Label Distribution Protocol

Label Distribution Protocol

Label Distribution Protocol (LDP) is used to distribute labels in non-traffic-engineered applications. LDP allows routers to establish LSPs through a network by mapping network-layer routing information directly to data link LSPs.

An LSP is defined by the set of labels from the ingress LER to the egress LER. LDP associates a Forwarding Equivalence Class (FEC) with each LSP it creates. A FEC is a collection of common actions associated with a class of packets. When an ingress LER assigns a label to a FEC, it must allow other LSRs in the path know about the label. LDP helps to establish the LSP by providing a set of procedures that LSRs can use to distribute labels.

The FEC associated with an LSP specifies which packets are mapped to that LSP. LSPs are extended through a network by each LSR, where each LSR splices incoming labels for the FEC to the outgoing label assigned to the next hop for the FEC.

LDP allows an LSR to request a label from a downstream LSR so it can bind the label to a specific FEC. The downstream LSR responds to the request from the upstream LSR by sending the requested label.

LSRs can distribute a FEC label binding in response to an explicit request from another LSR. This is known as Downstream On Demand (DOD) label distribution. LSRs can also distribute label bindings to LSRs that have not explicitly requested them. This is called Downstream Unsolicited (DU). For LDP on the 7705 SAR, Downstream Unsolicited (DU) mode is implemented.

This section contains the following topics:

LDP and MPLS

LDP performs dynamic label distribution in MPLS environments. The LDP operation begins with a Hello discovery process network to form an adjacency with an LDP peer in the network. LDP peers are two MPLS routers that use LDP to exchange label/FEC mapping information. An LDP session is created between LDP peers. A single LDP session allows each peer to learn the other's label mappings and to distribute its own label information (LDP is bidirectional), and exchange label binding information.

LDP signaling works with the MPLS label manager to manage the relationships between labels and the corresponding FEC. For service-based FECs, LDP works in tandem with the Service Manager to identify the virtual leased lines (VLLs) and pseudowires (PWs) to signal.

An MPLS label identifies a set of actions that the forwarding plane performs on an incoming packet before discarding it. The FEC is identified through the signaling protocol (in this case LDP), and is allocated a label. The mapping between the label and the FEC is communicated to the forwarding plane. In order for this processing on the packet to occur at high speeds, optimized tables that enable fast access and packet identification are maintained in the forwarding plane.

After an unlabeled packet ingresses the 7705 SAR, classification policies associate it with a FEC, the appropriate label is imposed on the packet, and then the packet is forwarded. Other actions can also take place on a packet before it is forwarded, including imposing additional labels, other encapsulations, or learning actions. After all actions associated with the packet are completed, the packet is forwarded.

When a labeled packet ingresses the router, the label or stack of labels indicates the set of actions associated with the FEC for that label or label stack. The actions are performed on the packet and then the packet is forwarded.

The LDP implementation provides support for DU, ordered control, and liberal label retention mode.

For LDP label advertisement, DU mode is supported. To prevent filling the uplink bandwidth with unassigned label information, Ordered Label Distribution Control mode is supported.

A PW/VLL label can be dynamically assigned by targeted LDP operations. Targeted LDP allows the inner labels (that is, the VLL labels) in the MPLS headers to be managed automatically. This makes it easier for operators to manage the VLL connections. There is, however, additional signaling and processing overhead associated with this targeted LDP dynamic label assignment.

BFD for T-LDP

BFD is a simple protocol for detecting failures in a network. BFD uses a ‟hello” mechanism that sends control messages periodically to the far end and receives periodic control messages from the far end. BFD is implemented in asynchronous mode only, meaning that neither end responds to control messages; rather, the messages are sent in the time period configured at each end.

A T-LDP session is a session between either directly or non-directly connected peers and requires that adjacencies be created between two peers. BFD for T-LDP sessions allows support for tracking of failures of nodes that are not directly connected. BFD timers must be configured under the system router interface context before being enabled under T-LDP.

BFD tracking of an LDP session associated with a T-LDP adjacency allows for faster detection of the status of the session by registering the loopback address of the peer as the transport address.

LDP architecture

LDP comprises a few processes that handle the protocol PDU transmission, timer-related issues, and protocol state machine. The number of processes is kept to a minimum to simplify the architecture and to allow for scalability. Scheduling within each process prevents starvation of any particular LDP session, while buffering alleviates TCP-related congestion issues.

The LDP subsystems and their relationships to other subsystems are illustrated in LDP subsystem interrelationships. This illustration shows the interaction of the LDP subsystem with other subsystems, including memory management, label management, service management, SNMP, interface management, and RTM. In addition, debugging capabilities are provided through the logger.

Communication within LDP tasks is typically done by interprocess communication through the event queue, as well as through updates to the various data structures. The following list describes the primary data structures that LDP maintains:

  • FEC/label database — this database contains all the FEC-to-label mappings, including both sent and received. It also contains both address FECs (prefixes and host addresses) as well as service FECs (L2 VLLs).

  • Timer database — this database contains all the timers for maintaining sessions and adjacencies

  • Session database — this database contains all the session and adjacency records, and serves as a repository for the LDP MIB objects

LDP subsystem interrelationships

LDP subsystem interrelationships shows the relationships between LDP subsystems and other 7705 SAR subsystems. The following sections describe how the subsystems work to provide services.

Memory manager and LDP

LDP does not use any memory until it is instantiated. It preallocates some amount of fixed memory so that initial startup actions can be performed. Memory allocation for LDP comes out of a pool reserved for LDP that can grow dynamically as needed.

Fragmentation is minimized by allocating memory in large chunks and managing the memory internally to LDP. When LDP is shut down, it releases all memory allocated to it.

Label manager

LDP assumes that the label manager is up and running. LDP aborts initialization if the label manager is not running. The label manager is initialized at system boot-up; therefore anything that causes it to fail likely indicates that the system is not functional. The 7705 SAR uses a label range from 28 672 (28K) to 131 071 (128K-1) to allocate all dynamic labels, including VC labels.

Figure 1. LDP subsystem interrelationships

LDP configuration

The 7705 SAR uses a single consistent interface to configure all protocols and services. CLI commands are translated to SNMP requests and are handled through an agent-LDP interface. LDP can be instantiated or deleted through SNMP. Also, targeted LDP sessions can be set up to specific endpoints. Targeted session parameters are configurable.

Logger

LDP uses the logger interface to generate debug information relating to session setup and teardown, LDP events, label exchanges, and packet dumps. Per-session tracing can be performed. See the 7705 SAR System Management Guide for logger configuration information.

Service manager

All interaction occurs between LDP and the service manager, because LDP is used primarily to exchange labels for Layer 2 services. In this context, the service manager informs LDP when an LDP session is to be set up or torn down, and when labels are to be exchanged or withdrawn. In turn, LDP informs the service manager of relevant LDP events, such as connection setups and failures, timeouts, and labels signaled or withdrawn.

Execution flow

LDP activity in the 7705 SAR is limited to service-related signaling. Therefore, the configurable parameters are restricted to system-wide parameters, such as hello and keepalive timeouts.

Initialization

MPLS must be enabled when LDP is initialized. LDP makes sure that the various prerequisites are met, such as ensuring that the system IP interface and the label manager are operational, and ensuring that there is memory available. It then allocates a pool of memory to itself and initializes its databases.

Session lifetime

In order for a targeted LDP session to be established, an adjacency has to be created. The LDP extended discovery mechanism requires hello messages to be exchanged between two peers for session establishment. After the adjacency is established, session setup is attempted.

Adjacency establishment

In the 7705 SAR, adjacency management is done through the establishment of a Service Destination Point (SDP) object, which is a service entity in the Nokia service model.

The service model uses logical entities that interact to provide a service. The service model requires the service provider to create and configure four main entities:

  • customers

  • services

  • Service Access Points (SAPs) on local 7705 SAR routers

  • SDPs that connect to one or more remote 7705 SAR routers or 77x0 SR routers

An SDP is the network-side termination point for a tunnel to a remote 7705 SAR or 77x0 SR router. An SDP defines a local entity that includes the system IP address of the remote 7705 SAR routers and 77x0 SR routers, and a path type.

Each SDP comprises:

  • the SDP ID

  • the transport encapsulation type, MPLS

  • the far-end system IP address

If the SDP is identified as using LDP signaling, then an LDP extended hello adjacency is attempted.

If another SDP is created to the same remote destination and if LDP signaling is enabled, no further action is taken, because only one adjacency and one LDP session exists between the pair of nodes.

An SDP is a unidirectional object, so a pair of SDPs pointing at each other must be configured in order for an LDP adjacency to be established. After an adjacency is established, it is maintained through periodic hello messages.

Session establishment

When the LDP adjacency is established, the session setup follows as per the LDP specification. Initialization and keepalive messages complete the session setup, followed by address messages to exchange all interface IP addresses. Periodic keepalives or other session messages maintain the session liveness.

Because TCP is back-pressured by the receiver, it is necessary to be able to push that back-pressure all the way into the protocol. Packets that cannot be sent are buffered on the session object and reattempted as the back-pressure eases.

Label exchange

Label exchange is initiated by the service manager. After an SDP is attached to a service (that is, after the service gets a transport tunnel), a message is sent from the service manager to LDP. This causes a label mapping message to be sent. Additionally, when the SDP binding is removed from the service, the VC label is withdrawn. The peer must send a label release to confirm that the label is not in use.

Implicit null label

The implicit null label option enables an eLER to receive MPLS packets from the previous-hop LSR without the outer LSP label.

The implicit null label is signaled by the eLER to the previous-hop LSR during FEC signaling by the LDP control protocol. When the implicit null label is signaled to the LSR, it pops the outer label before sending the MPLS packet to the eLER; this is known as penultimate hop popping.

The implicit null label option can be enabled for all LDP FECs for which the router is the eLER by using the implicit-null-label command in the config>router>ldp context.

If the implicit null configuration is changed, LDP withdraws all the FECs and readvertises them using the new label value.

Other reasons for label actions

Label actions can also occur for the following reasons:

  • MTU changes — LDP withdraws the previously assigned label and resignals the FEC with the new Maximum Transmission Unit (MTU) in the interface parameter

  • clear labels — when a service manager command is issued to clear the labels, the labels are withdrawn and new label mappings are issued

  • SDP down — when an SDP goes administratively down, the VC label associated with that SDP for each service is withdrawn

  • memory allocation failure — if there is no memory to store a received label, the received label is released

  • VC type unsupported — when an unsupported VC type is received, the received label is released

Cleanup

LDP closes all sockets, frees all memory, and shuts down all its tasks when it is deleted, so that it uses no memory (0 bytes) when it is not running.

LDP filters

The 7705 SAR supports both inbound and outbound LDP label binding filtering.

Inbound filtering (import policy) allows the user to configure a policy to control the label bindings an LSR (Label Switch Router) accepts from its peers.

Import policy label bindings can be filtered based on the following:

  • neighbor — match on bindings received from the specified peer

  • prefix-list — match on bindings with the specified prefix/prefixes

The default import behavior is to accept all FECs received from peers.

Outbound filtering (export policy) allows the user to configure a policy to control the set of LDP label bindings advertised by the LSR (Label Switch Router).

Because the default behavior is to originate label bindings for the system IP address only, when a non-default loopback address is used as the transport address, the 7705 SAR does not advertise the loopback FEC automatically. With LDP export policy, the user is now able to explicitly export the loopback address to advertise the loopback address label and allow the node to be reached by other network elements.

Export policy label bindings can be filtered based on the following:

  • all — all local subnets by specifying ‟direct” as the match protocol

  • prefix-list — match on bindings with the specified prefix/prefixes

Note: In order for the 7705 SAR to consider a received label to be active, there must be an exact match to the FEC advertised together with the label found in the routing table, or a longest prefix match (if the aggregate-prefix-match option is enabled; see Multi-area and multi-instance extensions to LDP). This can be achieved by configuring a static route pointing to the prefix encoded in the FEC.

Per-LDP peer export policies

Prefix export policies provide a way to control which FEC prefixes received from other LDP peers are redistributed to a specific LDP peer. By default, all FEC prefixes are exported to the LDP peer.

FEC prefix export policies are configured using the config>router>ldp>session-params>peer>export-prefixes policy-name command.

LDP FEC statistics

LDP FEC statistics allow operators to monitor traffic being forwarded between any two PE routers and for all services using an LDP SDP. LDP FEC statistics are available for the egress data path at the ingress LER and LSR. Because an ingress LER is also potentially an LSR for an LDP FEC, combined egress data path statistics are provided whenever applicable. For more information, see RSVP LSP and LDP FEC statistics.

Multi-area and multi-instance extensions to LDP

When a network has two or more IGP areas, or instances, inter-area LSPs are required for MPLS connectivity between the PE devices that are located in the distinct IGP areas. To extend LDP across multiple areas of an IGP instance or across multiple IGP instances, the current standard LDP implementation based on RFC 3036, LDP Specification, requires that all /32 prefixes of PEs be leaked between the areas or instances. IGP route leaking is the distribution of the PE loopback addresses across area boundaries. An exact match of the prefix in the routing table (RIB) is required to install the prefix binding in the FIB and set up the LSP.

This behavior is the default behavior for the 7705 SAR when it is configured as an Area Border Router (ABR). However, exact prefix matching causes performance issues for the convergence of IGP on routers deployed in networks where the number of PE nodes scales to thousands of nodes. Exact prefix matching requires the RIB and FIB to contain the IP addresses maintained by every LSR in the domain and requires redistribution of a large number of addresses by the ABRs. Security is a potential issue as well, as host routes leaked between areas can be used in DoS and DDoS attacks and spoofing attacks.

To prevent these performance and security issues, the 7705 SAR can be configured for an optional behavior in which LDP installs a prefix binding in the LDP FIB by performing a longest prefix match with an aggregate prefix in the routing table (RIB). This behavior is described in RFC 5283, LDP Extension for Inter-Area Label Switched Paths. The LDP prefix binding continues to be advertised on a per-individual /32 prefix basis.

When the longest prefix match option is enabled and an LSR receives a FEC-label binding from an LDP neighbor for a prefix-address FEC element, FEC1, it installs the binding in the LDP FIB if:

  • the routing table (RIB) contains an entry that matches FEC1. Matching can either be a longest IP match of the FEC prefix or an exact match.

  • the advertising LDP neighbor is the next hop to reach FEC1

When the FEC-label binding has been installed in the LDP FIB, LDP programs an NHLFE entry in the egress data path to forward packets to FEC1. LDP also advertises a new FEC-label binding for FEC1 to all its LDP neighbors.

When a new prefix appears in the RIB, LDP checks the LDP FIB to determine if this prefix is a closer match for any of the installed FEC elements. If a closer match is found, this may mean that the LSR used as the next hop changes; if so, the NHLFE entry for that FEC must be changed.

When a prefix is removed from the RIB, LDP checks the LDP FIB for all FEC elements that matched this prefix to determine if another match exists in the routing table. If another match exists, LDP must use it. This may mean that the LSR used as the next hop changes; if so, the NHLFE entry for that FEC must be changed. If another match does not exist, the LSR removes the FEC binding and sends a label withdraw message to its LDP neighbors.

If the next hop for a routing prefix changes, LDP updates the LDP FIB entry for the FEC elements that matched this prefix. It also updates the NHLFE entry for the FEC elements.

ECMP support for LDP

Equal-Cost Multipath Protocol (ECMP) support for LDP performs load balancing for services that use LDP-based LSPs as transport tunnels, by having multiple equal-cost outgoing next hops for an IP prefix.

ECMP for LDP load-balances traffic across all equal-cost links based on the output of the hashing algorithm using the allowed inputs, based on the service type. For additional information, see ‟LAG and ECMP Hashing” in the 7705 SAR Interface Configuration Guide.

There is only one next-hop peer for a network link. To offer protection from a network link or next-hop peer failure, multiple network links can be configured to connect to different next-hop peers, or multiple links to the same peer. For example, an MLPPP link and an Ethernet link can be connected to two peers, or two Ethernet links can be connected to the same peer. ECMP occurs when the cost of each link reaching a target IP prefix is equal.

The 7705 SAR uses a liberal label retention mode, which retains all labels for an IP prefix from all next-hop peers. A 7705 SAR acting as an LSR load-balances the MPLS traffic over multiple links using a hashing algorithm.

The 7705 SAR supports the following optional fields as hash inputs and supports profiles for various combinations:

  • hashing algorithms

    • label-only option: hashing is done on the MPLS label stack, up to a maximum of 10 labels (default)

    • label-IP option: hashing is done on the MPLS label stack and the IPv4 source and destination IP address if an IPv4 header is present after the MPLS labels

    • Layer 4 header (source or destination UDP or TCP port number) and TEID: hashing is done on the MPLS label stack, the IPv4 source and destination IP address (if present), then on the Layer 4 source and destination UDP or TCP port fields (if present) and the TEID in the GTP header (if present)

  • label stack profile options on significance of the bottom-of-stack label (VC label)

    • profile 1: favors better load balancing for pseudowires when the VC label distribution is contiguous (default)

    • profile 2: similar to profile 1 where the VC labels are contiguous, but provides an alternate distribution

    • profile 3: all labels have equal influence in hash key generation

  • ingress LAG port at the LSR (default is disabled)

    The use-ingress-port option, when enabled, specifies that the ingress port is used by the hashing algorithm at the LSR. This option should be enabled for ingress LAG ports because packets with the same label stack can arrive on all ports of a LAG interface. In this case, using the ingress port in the hashing algorithm results in better egress load balancing, especially for pseudowires.

    The option should be disabled for LDP ECMP so that the ingress port is not used by the hashing algorithm. For ingress LDP ECMP, if the ingress port is used by the hashing algorithm, the hash distribution could be biased, especially for pseudowires.

  • system IP address – hashing on the system IP address is enabled and disabled at the system level only

All of the above options can be configured with the lsr-load-balancing command, with the exception of the system IP address, which is configured with the system-ip-load-balancing command.

Note: The global IF index is no longer a hash input for LSR ECMP load balancing. It has been replaced with the use-ingress-port configurable option in the lsr-load-balancing command. As well, the default treatment of the MPLS label stack has changed to focus on the bottom-of-stack label (VC label). In previous releases, all labels had equal influence.

LSR load balancing can be configured at the system level or interface level. Configuration at the interface level overrides the system-level settings for the specific interface. Configuration must be done on the ingress network interface (that is, the interface on the LDP LSR node that the packet is received on).

Configuration of load balancing at the interface level provides some control to the user; for example, the label-IP option can be disabled on a specific interface if labeled packets received on the interface include non-IP packets that can be confused by the hash routine for IP packets. Disabling the label-IP option can be used in cases where the first nibble of a non-IP packet is a 4, which would result in the packet being hashed incorrectly if the label-IP option was enabled.

If ECMP is not enabled, the label from only one of the next-hop peers is selected and installed in the forwarding plane. In this case, the algorithm used to distribute the traffic flow looks up the route information, and selects the network link with the lowest IP address. If the selected network link or next-hop peer fails, another next-hop peer is selected, and LDP reprograms the forwarding plane to use the label sent by the newly selected peer.

ECMP is supported on all Ethernet ports in network mode, and is also supported on the 4-port OC3/STM1 Clear Channel Adapter card when it is configured for POS (ppp-auto) encapsulation and network mode.

For information about configuring the 7705 SAR for LSR ECMP, see the lsr-load-balancing and system-ip-load-balancing commands in the 7705 SAR Basic System Configuration Guide, ‟System Information and General Commands” and the lsr-load-balancing command in the 7705 SAR Router Configuration Guide, ‟Router Interface Commands”.

For information about LDP treetrace commands for tracing ECMP paths, see the 7705 SAR OAM and Diagnostics Guide.

Note: LDP treetrace works best with label-IP hashing (lbl-ip) enabled, instead of label-only (lbl-only) hashing. These options are set with the lsr-load-balancing command.
Note:
  • Because of the built-in timeout to dynamic ARP, the MAC address of the remote peer needs to be renewed periodically. The flow of IP traffic resets the timers back to their maximum values. In the case of LDP ECMP, one link could be used for transporting user MPLS (pseudowire) traffic but the LDP session could possibly be using a different equal-cost link. For LDPs using ECMP and for static LSPs, it is important to ensure that the remote MAC address is learned and does not expire. Configuring static ARP entries or running continuous IP traffic ensures that the remote MAC address is always known. Running BFD for fast detection of Layer 2 faults or running any OAM tools with SAA ensures that the learned MAC addresses do not expire.

  • ARP entries are refreshed by static ARP and BFD, SAA, OSPF, IS-IS, or BGP.

  • For information about configuring static ARP and running BFD, see the 7705 SAR Router Configuration Guide.

Label operations

If an LSR is the ingress router for a specific IP prefix, LDP programs a PUSH operation for the prefix in the IOM. This creates an LSP ID to the Next Hop Label Forwarding Entry (NHLFE) mapping (LTN mapping) and an LDP tunnel entry in the forwarding plane. LDP also informs the Tunnel Table Manager (TTM) about this tunnel. Both the LSP ID to NHLFE (LTN) entry and the tunnel entry have an NHLFE for the label mapping that the LSR received from each of its next-hop peers.

If the LSR is to function as a transit router for a specific IP prefix, LDP programs a SWAP operation for the prefix in the IOM. This involves creating an Incoming Label Map (ILM) entry in the forwarding plane. The ILM entry may need to map an incoming label to multiple NHLFEs.

If an LSR is an egress router for a specific IP prefix, LDP programs a POP entry in the IOM. This too results in an ILM entry being created in the forwarding plane, but with no NHLFEs.

When unlabeled packets arrive at the ingress LER, the forwarding plane consults the LTN entry and uses a hashing algorithm to map the packet to one of the NHLFEs (PUSH label) and forward the packet to the corresponding next-hop peer. For a labeled packet arriving at a transit or egress LSR, the forwarding plane consults the ILM entry and either uses a hashing algorithm to map it to one of the NHLFEs if they exist (SWAP label) or routes the packet if there are no NHLFEs (POP label).

Graceful Restart Helper

Graceful Restart (GR) is part of the LDP handshake process (that is, the LDP peering session initialization) and needs to be supported by both peers. GR provides a mechanism that allows the peers to cope with a service interruption because of a CSM switchover, which is a period of time when the standby CSM is not capable of synchronizing the states of the LDP sessions and labels being advertised and received.

Graceful Restart Helper (GR-Helper) decouples the data plane from the control plane so that if the control plane is not responding (that is, there is no LDP message exchange between peers), then the data plane can still forward frames based on the last known (advertised) labels.

Because the 7705 SAR supports non-stop services / high-availability for LDP (and MPLS), the full implementation of GR is not needed. However, GR-Helper is implemented on the 7705 SAR to support non-high-availability devices. With GR-Helper, if an LDP peer of the 7705 SAR requests GR during the LDP handshake, the 7705 SAR agrees to it but does not request GR. For the duration of the LDP session, if the 7705 SAR LDP peer fails, the 7705 SAR continues to forward MPLS packets based on the last advertised labels and does not declare the peer dead until the GR timer expires.

Graceful handling of resource exhaustion

Graceful handling of resource exhaustion enhances the behavior of LDP when a data path or a CSM resource required for the resolution of a FEC is exhausted. In prior releases, the entire LDP protocol was shut down, causing all LDP peering sessions to be torn down and therefore impacting all peers. The user was required to fix the issue that caused the FEC scaling to be exceeded, and to restart the LDP session by executing the no shutdown CLI command. With graceful handling of resource exhaustion, only the responsible session or sessions are shut down, which impacts only the appropriate peer or peers.

Graceful handling of resources implements a capability by which the LDP interface to the peer, or the targeted peer in the case of a targeted LDP (T-LDP) session, is shut down.

If LDP tries to resolve a FEC over a link or a T-LDP session and runs out of data path or CSM resources, LDP brings down that interface or targeted peer, which brings down the Hello adjacency over that interface to all linked LDP peers or to the targeted peer. The interface is brought down for the LDP context only and is still available to other applications such as IP forwarding and RSVP LSP forwarding.

After taking action to free up resources, the user must manually perform a no shutdown command on the interface or the targeted peer to bring it back into operation. This re-establishes the Hello adjacency and resumes the resolution of FECs over the interface or to the targeted peer.

LDP support for unnumbered interfaces

Unnumbered interfaces are point-to-point interfaces that are not explicitly configured with a dedicated IP address and subnet; instead, they borrow (or link to) an IP address from another interface on the system (the system IP address, another loopback interface, or any other numbered interface) and use it as the source IP address for packets originating from the interface. For more information about support for unnumbered interfaces, see the 7705 SAR Router Configuration Guide, ‟Unnumbered Interfaces”.

This feature allows LDP to establish a Hello adjacency and to resolve unicast FECs over unnumbered LDP interfaces.

For example, LSR A and LSR B are the two endpoints of an unnumbered link. These interfaces are identified on each system with their unique link local identifier. The combination router ID and link local identifier uniquely identifies the interface in IS-IS throughout the network.

A borrowed IP address is also assigned to the interface to be used as the source address of IP packets that must originate from the interface. The borrowed IP address defaults to the system interface address, A and B in this example. The borrowed IP interface can be configured to any IP interface by using the following CLI command: config> router>interface>unnumbered {ip-int-name | ip-address}.

The fec-originate command, which defines how to originate a FEC for egress and non-egress LSRs, includes a parameter to specify the name of the interface that the label for the originated FEC is swapped to. For an unnumbered interface, this parameter is mandatory because an unnumbered interface does not have its own IP address.

When the unnumbered interface is added into LDP, the follow behavior occurs.

For link LDP (L-LDP) sessions:

  1. The Hello adjacency is brought up using a link Hello packet with the source IP address set to the interface borrowed IP address and a destination IP address set to 224.0.0.2.

  2. Hello packets with the same source IP address should be accepted when received over parallel unnumbered interfaces from the same peer LSR ID. The corresponding Hello adjacencies are associated with a single LDP session.

  3. The transport address for the TCP connection, which is encoded in the Hello packet, is always set to the LSR ID of the node whether the interface option was enabled using the config>router>ldp>interface-parameters> interface>transport-address command.

  4. The local-lsr-id option can be configured on the interface and the value of the LSR ID can be changed to either the local interface or to some other interface name. If the local interface is selected or the provided interface name corresponds to an unnumbered IP interface, the unnumbered interface borrowed IP address is used as the LSR ID. In all cases, the transport address for the LDP session is updated to the new LSR ID value, but the link Hello packets continue to use the interface borrowed IP address as the source IP address.

  5. The LSR with the highest transport address, the LSR ID in this case, bootstraps the TCP connection and LDP session.

  6. The source and destination IP addresses of LDP packets are the transport addresses, that is, the LDP LSR IDs of the LSRs at the endpoints of the link (A and B in the example).

For targeted LDP (T-LDP) sessions:

  1. The source and destination addresses of the targeted Hello packet are the LDP LSR IDs of systems A and B.

  2. The local-lsr-id option can be configured on the interface for the targeted session and the value of the LSR ID can be changed to either the local interface or to some other interface name. If the local interface is selected or the provided interface name corresponds to an unnumbered IP interface, the unnumbered interface borrowed IP address is used as the LSR ID. In all cases, the transport address for the LDP session and the source IP address of the targeted Hello message are updated to the new LSR ID value.

  3. The LSR with the highest transport address, the LSR ID in this case, bootstraps the TCP connection and LDP session.

  4. The source and destination IP addresses of LDP packets are the transport addresses, that is, the LDP LSR IDs of the LSRs at the endpoints of the link (A and B in the example).

FEC resolution:

  • LDP advertises/withdraws unnumbered interfaces using the Address/Address-Withdraw message. The borrowed IP address of the interface is used.

  • A FEC can be resolved to an unnumbered interface in the same way as it is resolved to a numbered interface. The outgoing interface and next hop are looked up in the RTM cache. The next hop is the router ID and link identifier of the interface at the peer LSR.

  • LDP FEC ECMP next hops over a mix of unnumbered and numbered interfaces are supported.

  • All LDP FEC types are supported.

  • The fec-originate command is supported when the next hop is over an unnumbered interface.

All LDP features supported for numbered IP interfaces are supported for unnumbered interfaces, with the following exceptions:

  • BFD is not supported on unnumbered IP interfaces

  • LDP FRR is not triggered by a BFD session timeout, only by a physical failure or the local interface going down

  • unnumbered IP interfaces cannot be added into LDP global and peer prefix policies

The unnumbered interface feature also extends the support of LSP ping and LSP traceroute to test an LDP unicast FEC that is resolved over an unnumbered LDP interface.

LDP Fast Reroute (FRR)

LDP Fast Reroute (FRR) provides local protection for an LDP FEC by precalculating and downloading a primary and a backup NHLFE for the FEC to the LDP FIB. The primary NHLFE corresponds to the label of the FEC received from the primary next hop as per the standard LDP resolution of the FEC prefix in the RTM. The backup NHLFE corresponds to the label received for the same FEC from a Loop-Free Alternate (LFA) next hop.

LDP FRR protects against single link or single node failure. SRLG failure protection is not supported.

Without FRR, when a local link or node fails, the router must signal the failure to its neighbors via the IGP providing the routing (OSPF or IS-IS), recalculate primary next-hop NHLFEs for all affected FECs, and update the FIB. Until the new primary next hops are installed in the FIB, any traffic destined for the affected FECs is discarded. This process can take hundreds of milliseconds.

LDP FRR improves convergence in case of a local link or node failure in the network, by using the label-FEC binding received from the LFA next hop to forward traffic for a specific prefix as soon as the primary next hop is not available. This means that a router resumes forwarding LDP packets to a destination prefix using the backup path without waiting for the routing convergence. Convergence times should be similar to RSVP-TE FRR, in the tens of milliseconds.

OSPF or IS-IS must perform the Shortest Path First (SPF) calculation of an LFA next hop, as well as the primary next hop, for all prefixes used by LDP to resolve FECs. The IGP also populates both routes in the RTM.

When LDP FRR is enabled and an LFA backup next hop exists for the FEC prefix in the RTM, or for the longest prefix the FEC prefix matches to when the aggregate-prefix-match option is enabled, LDP programs the data path with both a primary NHLFE and a backup NHLFE for each next hop of the FEC.

To perform a switchover to the backup NHLFE in the fast path, LDP follows the standard FRR failover procedures, which are also supported for RSVP-TE FRR.

When any of the following events occurs, the backup NHLFE is enabled for each affected FEC next hop:

  • an LDP interface goes operationally down or is administratively shut down

    In this case, LDP sends a neighbor/next hop down message to each LDP with which it has an adjacency over the interface.

  • an LDP session to a peer goes down because the Hello timer or keepalive timer has expired over an interface

    In this case, LDP sends a neighbor/next hop down message to the affected peer.

  • the TCP connection used by a link LDP session to a peer goes down

    In this case, LDP sends a neighbor/next hop down message to the affected peer.

See RFC 5286, Basic Specification for IP Fast Reroute: Loop-Free Alternates, for more information about LFAs.

ECMP vs FRR

If ECMP is enabled, which provides multiple primary next hops for a prefix, LDP FRR is not used. That is, the LFA next hops are not populated in the RTM and the ECMP paths are used instead.

IGP shortcuts (RSVP-TE tunnels)

IGP shortcuts are an MPLS functionality where LSPs are treated like physical links within IGPs; that is, LSPs can be used for next-hop reachability. If an RSVP-TE LSP is used as a shortcut by OSPF or IS-IS, it is included in the SPF calculation as a point-to-point link for both primary and LFA next hops. It can also be advertised to neighbors so that the neighboring nodes can also use the links to reach a destination via the advertised next hop.

IGP shortcuts can be used to simplify remote LFA support and simplify the number of LSPs required in a ring topology.

When both IGP shortcuts and LFA are enabled under OSPF or IS-IS, and LDP FRR is also enabled, the following applies:

  • a FEC that is resolved to a direct primary next hop can be backed up by a tunneled LFA next hop

  • a FEC that is resolved to a tunneled primary next hop does not have an LFA next hop; it relies on RSVP-TE FRR for protection

LDP FRR configuration

To configure LDP FRR, LFA calculation by the SPF algorithm must first be enabled under the OSPF or IS-IS protocol level with the command:

config>router>ospf>loopfree-alternates

or

config>router>ospf3>loopfree-alternates

or

config>router>isis>loopfree-alternates

Next, LDP must be enabled to use the LFA next hop with the command config>router>ldp>fast-reroute.

If IGP shortcuts are used, they must be enabled under the OSPF or IS-IS routing protocol. As well, they must be enabled under the MPLS LSP context, using the command config>router>mpls>lsp>igp-shortcut.

For information about LFA and IGP shortcut support for OSPF and IS-IS, see the 7705 SAR Routing Protocols Guide, ‟LDP and IP Fast Reroute for OSPF Prefixes” and ‟LDP and IP Fast Reroute for IS-IS Prefixes”.

Both LDP FRR and IP FRR are supported; for information about IP FRR, see the 7705 SAR Router Configuration Guide, ‟IP Fast Reroute (FRR)”.

LDP-to-segment routing stitching for IPv4 /32 prefixes (IS-IS)

This feature provides stitching between an LDP FEC and an SR node SID route for the same IPv4 /32 IS-IS prefix by allowing the export of SR tunnels from the Tunnel Table Manager (TTM) to LDP (IGP). In the LDP-to-SR data path direction, the LDP tunnel table route export policy supports the exporting of SR tunnels from the TTM to LDP.

A route policy option is configured to support LDP-to-SR stitching using the config>router>policy-options context. See the 7705 SAR Router Configuration Guide, ‟Configuring LDP-to-Segment Routing Stitching Policies”, for a configuration example and to ‟Route Policy Command Reference” for information about the commands that are used.

After the route policy option is configured, the SR tunnels are exported from the TTM into LDP (IGP) using the config>router>ldp>export-tunnel-table command. See LDP command reference for more information about this command.

When configuring a route policy option, the user can restrict the exporting of SR tunnels from the TTM to LDP from a specific prefix list by excluding the prefix from the list.

The user can also restrict the exporting of SR tunnels from the TTM to a specific IS-IS IGP instance by specifying the instance ID in the from protocol statement. The from protocol statement is valid only when the protocol value is isis. Policy entries with any other protocol value are ignored when the route policy is applied. If the user configures multiple from protocol statements in the same policy or does not include the from protocol statement but adds a default-action of accept, then LDP routing uses the lowest instance ID in the IS-IS protocol to select the SR tunnel.

When the routing policy is enabled, LDP checks the SR tunnel entries in the TTM. Whenever an LDP FEC primary next hop cannot be resolved using an RTM route and an SR tunnel of type isis to the same destination IPv4 /32 prefix matches an entry in the export policy, LDP programs an LDP ILM and stitches it to the SR node SID tunnel endpoint. LDP then originates a FEC for the prefix and redistributes it to its LDP peer. When a LDP FEC is stitched to an SR tunnel, forwarded packets benefit from the protection of the LFA/remote LFA or TI-LFA backup next hop of the SR tunnel.

When resolving a FEC, LDP attempts a resolution in the RTM before attempting a resolution in the TTM, when both are available. That is, a swapping operation from the LDP ILM to an LDP NHLFE is attempted before stitching the LDP ILM to an SR tunnel endpoint.

In the SR-to-LDP data path direction, the SR mapping server provides a global policy for the prefixes corresponding to the LDP FECs the SR needs to stitch to. Therefore, a tunnel table export policy is not used. The user enables the exporting of the LDP tunnels for FEC prefixes advertised by the mapping server to an IGP instance using the command config>router>isis>segment-routing>export-tunnel-table ldp. See the 7705 SAR Routing Protocols Guide, ‟IS-IS Command Reference”, for more information about this command.

When the export-tunnel-table ldp command is enabled, the IGP monitors the LDP tunnel entries in the TTM. Whenever an IPv4 /32 LDP tunnel destination matches a prefix for which the IGP received a prefix SID sub-TLV from the mapping server, the IGP instructs the SR module to program the SR ILM and to stitch it to the LDP tunnel endpoint. The SR ILM can stitch to an LDP FEC resolved over the LDP link. When an SR tunnel is stitched to an LDP FEC, forwarded packets benefit from the protection of the LFA backup next hop of the LDP FEC.

When resolving a node SID, the IGP attempts a resolution of the prefix SID received in an IP reachability TLV before attempting a resolution of a prefix SID received via the mapping server, when both are available. That is, a swapping operation of the SR ILM to an SR NHLFE is attempted before stitching it to an LDP tunnel endpoint. See the 7705 SAR Routing Protocols Guide, ‟Prefix SID Resolution for a Segment Routing Mapping Server”, for more information about prefix SID resolution.

It is recommended that the bfd-enable option be enabled on the interfaces for both LDP and IGP contexts to speed up the failure detection and the activation of the LFA/remote LFA backup next hop in either direction. This applies particularly for remote failures. For the LDP context, the config>router>ldp>interface-parameters>interface>bfd-enable command string is used; see LDP commands. For the IGP context, the config>router>isis>interface>bfd-enable command string is used; see the 7705 SAR Routing Protocols Guide, ‟IS-IS Command Reference”.

The sections that follow describe how stitching is performed in the LDP-to-SR and SR-to-LDP data path directions.

Stitching in the LDP-to-SR direction

Stitching in the data plane in the LDP-to-SR direction is based on the LDP module monitoring the TTM for an SR tunnel of a prefix matching an entry in the LDP TTM export policy.

Figure 2. Stitching in the LDP-to-SR direction

In Stitching in the LDP-to-SR direction, router R1 is at the boundary between an SR domain and an LDP domain and is configured to stitch between SR and LDP. Link R1-R2 is LDP-enabled, but router R2 does not support SR or SR is disabled.

The following steps are performed by the boundary router R1 to configure stitching:

  1. Router R1 receives a prefix SID sub-TLV in an IS-IS IP reachability TLV originated by router Ry for prefix Y.

  2. R1 resolves the prefix SID and programs an NHLFE on the link toward the next hop in the SR domain. R1 programs an SR ILM and points it to the NHLFE.

  3. Because R1 is programmed to stitch LDP to SR, LDP in R1 checks the TTM and finds the SR tunnel to prefix Y. LDP programs an LDP ILM and points it to the SR tunnel. As a result, both the SR ILM and LDP ILM are now pointing to the SR tunnel, one via the SR NHLFE and the other via the SR tunnel endpoint.

  4. R1 advertises the LDP FEC for prefix Y to all its LDP peers. R2 is now able to install an LDP tunnel toward Ry.

  5. If R1 finds multiple SR tunnels to destination prefix Y, R1 uses the lowest instance ID in the IS-IS protocol to select the tunnel.

  6. If the user configured multiple from statements or did not include the from statement but added a default action of accept for the IS-IS protocol, R1 selects the tunnel to destination prefix Y by using the lowest instance ID in the IS-IS protocol.

    Note: If R1 has already resolved an LDP FEC for prefix Y, it has an ILM assigned to it. However, this ILM is not updated to point toward the SR tunnel because LDP attempts a resolution in the RTM before attempting a resolution in the TTM. Therefore, an LDP tunnel is selected before an SR tunnel. Similarly, if an LDP FEC is received after the stitching is programmed, the LDP ILM is updated to point to the LDP NHLFE because LDP is able to resolve the LDP FEC in the RTM.
  7. The user enables SR in R2. R2 resolves the prefix SID for prefix Y and installs the SR ILM and the SR NHLFE. R2 is now able to forward packets over the SR tunnel to router Ry. There is no activity in R1 because the SR ILM is already programmed.

  8. The user disables LDP over the R1-R2 interface in both directions. This causes the LDP FEC ILM and NHLFE to be removed in R1 and in R2, which can then only do forwarding using the SR tunnel toward Ry.

Stitching in the SR-to-LDP direction

Stitching in the data plane in the SR-to-LDP direction is based on the IGP monitoring the TTM for an LDP tunnel of a prefix matching an entry in the SR TTM export policy.

In Stitching in the LDP-to-SR direction, router R1 is at the boundary between an SR domain and an LDP domain and is configured to stitch between SR and LDP. Link R1-R2 is LDP-enabled but router R2 does not support SR or SR is disabled.

The following steps are performed by the boundary router R1 to configure stitching:

  1. R1 receives an LDP FEC for prefix X from router Rx in the LDP domain. The RTM in R1 indicates that the interface to R2 is the next hop for prefix X.

  2. LDP in R1 resolves the received FEC in the RTM and creates an LDP ILM for the FEC with an ingress label (for example, label L1), and points it to an LDP NHLFE toward R2 with egress label L2.

  3. R1 receives a prefix SID sub-TLV from the R5 mapping server for prefix X.

  4. The IGP in R1 attempts to resolve in its routing table the next hop of prefix X over the interface to R2. R1 detects that R2 did not advertise support of SR and therefore the SID resolution for prefix X in the routing table fails.

  5. The IGP in R1 then attempts to resolve the prefix SID of prefix X in the TTM because it detects that it is configured for SR-to-LDP stitching. R1 finds an LDP tunnel to prefix X in the TTM, instructs the SR module to program an SR ILM with ingress label L3, and points it to the LDP tunnel endpoint, therefore stitching ingress label L3 to egress label L2.

    Note:

    • The ILMs for LDP and SR are both pointing to the same LDP tunnel, one via NHLFE and one via the tunnel endpoint.

    • No SR tunnel to destination prefix X should be programmed in the TTM following the resolution of the prefix SID of prefix X in the TTM.

    • If the IGP is not able to resolve the SID resolution for prefix X in step4 and step5, a trap is generated for the prefix SID resolution failure. An existing trap for the prefix SID resolution failure is enhanced to state whether the prefix SID that failed the resolution attempts was part of a mapping server TLV or an IP reachability TLV.

  6. The user enables segment routing on R2.

  7. The IGP in R1 discovers that R2 supports SR.

    Because R1 still has a prefix SID for prefix X from the mapping server R5, it maintains the stitching of the SR ILM for prefix X to the LDP FEC.

  8. The user disables the LDP interface between R1 and R2 in both directions. This causes the LDP FEC ILM and NHLFE for prefix X to be removed in R1 and triggers the re-evaluation of the SIDs.

  9. R1 first attempts the resolution in the routing table. Because the next hop for prefix X supports SR, the IGP instructs the SR module to program an NHLFE for the prefix SID of prefix X with egress label L4 and with an outgoing interface to R2. R1 creates an SR tunnel in the TTM for destination prefix X. R1 also changes the SR ILM with ingress label L3 to point to the SR NHLFE with egress label L4.

    Router R2 now becomes the SR-LDP stitching router.

  10. Router Rx, which owns prefix X, is upgraded to support SR. Rx sends a prefix SID sub-TLV to R1 in an IS-IS IP reachability TLV for prefix X. The SID information may or may not be the same as the information received from the mapping server R5. If the SID information is not the same, the IGP in R1 chooses the prefix SID originated by Rx and updates the SR ILM and NHLFE with the appropriate labels.

  11. The user then cleans up the mapping server and removes the mapping entry for prefix X, which is then withdrawn by IS-IS.

TTL propagation and ICMP tunneling

When stitching is performed between an LDP FEC and an SR IS-IS node SID tunnel, the TTL of the outer LDP or SR label is decreased, similar to a regular swapping operation at an LSR.

LDP FRR remote LFA and TI-LFA backup using an SR tunnel for IPv4 /32 prefixes (IS-IS)

This feature allows an SR tunnel to be used as a remote LFA or TI-LFA backup tunnel next hop by an LDP FEC. The feature is enabled using the CLI command string config>router>ldp>fast-reroute backup-sr-tunnel. See LDP commands for more information.

This feature requires the LDP-to-segment routing stitching for IPv4 /32 prefixes (IS-IS) feature as a prerequisite, because the LSR performs the stitching of the LDP ILM to an SR tunnel when the primary LDP next hop of the FEC fails. Therefore, LDP monitors SR tunnels programmed by the IGP in the TTM without the need for a mapping server.

It is assumed that:

  • the backup-sr-tunnel option is enabled in LDP

  • the loopfree-alternates ti-lfa or loopfree-alternates remote-lfa option is enabled in the IGP instance (see the 7705 SAR Routing Protocols Guide, ‟IS-IS Command Reference”)

    Note: The loopfree-alternates options can be enabled separately or together. If both options are enabled, TI-LFA backup takes precedence over remote LFA backup.
  • LDP was able to resolve the primary next hop of the LDP FEC in the RTM

If the IGP LFA SPF does not find a regular LFA backup next hop for an LDP FEC prefix, it runs the TI-LFA and remote LFA algorithms. If the IGP LFA SPF finds a remote LFA or TI-LFA tunnel next hop, LDP programs the primary next hop of the FEC using an LDP NHLFE and programs the remote LFA or TI-LFA backup tunnel next hop using an LDP NHLFE pointing to the SR tunnel endpoint.

Note: The LDP packet is not sent over the SR tunnel. The LDP label is stitched to the segment routing label stack. LDP points both the LDP ILM and the LTN to the backup LDP NHLFE, which uses the SR tunnel endpoint.

Feature behavior

The following describes the behavior of this feature.

  • When LDP resolves a primary next hop in the RTM or a remote LFA or TI-LFA backup next hop using an SR tunnel in the TTM, LDP programs a primary LDP NHLFE and a backup LDP NHLFE with an implicit null label value pointing to the SR tunnel that has the remote LFA or TI-LFA backup programmed for the same prefix.

  • If the LDP FEC primary next hop fails and LDP has preprogrammed a remote LFA and TI-LFA next hop with an LDP backup NHLFE pointing to an SR tunnel, the LDP ILM/LTN switches to it.

    Note: If the LDP FEC primary next hop failure impacts only the LDP tunnel primary next hop but not the SR tunnel primary next hop, the LDP backup NHLFE points to the primary next hop of the SR tunnel; the LDP ILM/LTN traffic follows this path instead of the remote LFA or TI-LFA next hop of the SR tunnel until the remote LFA or TI-LFA next hop is activated.
  • If the LDP FEC primary next hop becomes unresolved in the RTM, LDP switches the resolution to an SR tunnel in the TTM, if one exists, following the steps described in Stitching in the LDP-to-SR direction.

  • If both the LDP primary next hop and a regular LFA next hop become resolved in RTM, the LDP FEC programs the primary NHLFE and backup NHLFE.

TCP MD5 authentication

The operation of a network can be compromised if an unauthorized system is able to form or hijack an LDP session and inject control packets by falsely representing itself as a valid neighbor. This risk can be mitigated by enabling TCP MD5 authentication on one or more of the sessions.

When TCP MD5 authentication is enabled on a session, every TCP segment exchanged with the peer includes a TCP option (19) containing a 16-byte MD5 digest of the segment (more specifically the TCP/IP pseudo-header, TCP header, and TCP data). The MD5 digest is generated and validated using an authentication key that must be known to both sides. If the received digest value is different from the locally computed one, the TCP segment is dropped, thereby protecting the router from a spoofed TCP segment.

The TCP Enhanced Authentication Option, as specified in draft-bonica-tcpauth-05.txt, Authentication for TCP-based Routing and Management Protocols, is a TCP extension that enhances security for LDP, BGP, and other TCP-based protocols. It extends the MD5 authentication option to include the ability to change keys in an LDP or BGP session seamlessly without tearing down the session, and allows for stronger authentication algorithms to be used. It is intended for applications where secure administrative access to both endpoints of the TCP connection is normally available.

TCP peers can use this extension to authenticate messages passed between one another. This strategy improves upon the practice described in RFC 2385, Protection of BGP Sessions via the TCP MD5 Signature Option. Using this new strategy, TCP peers can update authentication keys during the lifetime of a TCP connection. TCP peers can also use stronger authentication algorithms to authenticate routing messages.

TCP enhanced authentication uses keychains that are associated with every protected TCP connection.

Keychains are configured in the config>system>security>keychain context. For more information about configuring keychains, see the 7705 SAR System Management Guide, ‟TCP Enhanced Authentication and Keychain Authentication”.

LDP point-to-multipoint support

The 7705 SAR supports point-to-multipoint mLDP. This section contains information about the following topics:

LDP point-to-multipoint configuration

A node running LDP also supports point-to-multipoint LSP setup using LDP. By default, the node advertises the capability to a peer node using the point-to-multipoint capability TLV in LDP initialization message.

The multicast-traffic configuration option (per interface) restricts or allows the use of an interface for LDP multicast traffic forwarding toward a downstream node. The interface configuration option does not restrict or allow the exchange of the point-to-multipoint FEC by way of an established session to the peer on an interface, but only restricts or allows the use of next hops over the interface.

LDP point-to-multipoint protocol

Only a single generic identifier range is defined for signaling a multipoint data tree (MDT) for all client applications. Implementation on the 7705 SAR reserves the range 1 to 8292 for generic point-to-multipoint LSP ID values for static point-to-multipoint LSP on the root node.

Make-before-break (MBB)

After a transit or leaf node detects that the upstream node toward the root node of a multicast tree has changed, the node follows the graceful procedure that allows make-before-break transition to the new upstream node. Make-before-break support is optional via the mp-mbb-time command. If the new upstream node does not support MBB procedures, the downstream node waits for the configured timer to time out before switching over to the new upstream node.

ECMP support

If multiple ECMP paths exist between two adjacent nodes, then the upstream node of the multicast receiver programs all entries in the forwarding plane. Only one entry is active and it is based on the ECMP hashing algorithm.

Inter-AS non-segmented mLDP

This feature allows multicast services to use segmented protocols and span them over multiple autonomous systems (ASs) in the same way as unicast services. Because IP VPN or GRT services span multiple IGP areas or multiple ASs, either for a network designed to deal with scale or as result of commercial acquisitions, operators may require inter-AS VPN (unicast) connectivity. For example, an inter-AS VPN can break the IGP, MPLS, and BGP protocols into access segments and core segments, allowing higher scaling of protocols by segmenting them into their own islands. The 7705 SAR allows for a similar provisioning of multicast services and for spanning these services over multiple IGP areas or multiple ASs.

Multicast LDP (mLDP) supports non-segmented mLDP trees for inter-AS solutions that are applicable for NG-MVPN services.

LDP recursive FEC process

For inter-AS networks where the leaf node does not have the root in the RTM or where the leaf node has the root in the RTM using BGP, and the leaf’s local AS intermediate nodes do not have the root in their RTM because they are not BGP-enabled, RFC 6512 defines a recursive opaque value and procedure for LDP to build an LSP through multiple ASs.

For mLDP to be able to signal through a multiple-AS network where the intermediate nodes do not have a routing path to the root, a recursive opaque value is needed. The LDP FEC root resolves the local ASBR, and the recursive opaque value contains the point-to-multipoint FEC element, encoded as specified in RFC 6513, with a type field, a length field, and a value field of its own.

RFC 6826 section 3 defines the Transit IPv4 opaque for point-to-multipoint LDP FEC, where the leaf in the local AS wants to establish an LSP to the root for point-to-multipoint LSP. mLDP FEC for single AS with transit IPv4 opaque shows FEC in this network configuration.

Figure 3. mLDP FEC for single AS with transit IPv4 opaque

mLDP FEC for inter-AS with recursive opaque value shows an inter-AS FEC with recursive opaque based on RFC 6512.

Figure 4. mLDP FEC for inter-AS with recursive opaque value

As shown in mLDP FEC for inter-AS with recursive opaque value, the root ‟10.0.0.21” is an ASBR and the opaque value contains the original mLDP FEC. Therefore, in the leaf AS where the actual root ‟10.0.0.14” is not known, the LDP FEC can be routed using the local root of ASBR. When the FEC arrives at an ASBR that is colocated in the same AS as the actual root, an LDP FEC with transit IPv4 opaque is generated.

Non-VPN mLDP with recursive opaque for inter-AS shows an end-to-end example of a non-VPN mLDP with recursive opaque for inter-AS.

Figure 5. Non-VPN mLDP with recursive opaque for inter-AS

As shown in Non-VPN mLDP with recursive opaque for inter-AS, the leaf is in AS3s where the AS3 intermediate nodes do not have ROOT-1 in their RTM. The leaf has S1 installed in the RTM via BGP. All ASBRs are acting as next-hop-self in the BGP domain. The leaf resolving S1 via BGP generates an mLDP FEC with recursive opaque, represented as:

Leaf FEC: <Root=ASBR-3, opaque-value=<Root=Root-1, <opaque-value = S1,G1>>>

This FEC is routed through the AS3 Core to ASBR-3.

Note: AS3 intermediate nodes are not BGP-capable because they do not have ROOT-1 in their RTM.

At ASBR-3, the FEC is changed to:

ASBR-3 FEC: <Root=ASBR-1, opaque-value=<Root=Root-1, <opaque-value = S1,G1>>>

This FEC is routed from ASBR-3 to ASBR-1. ASBR-1 is colocated in the same AS as ROOT-1. Therefore, ASBR-1 does not need a FEC with a recursive opaque value.

ASBR-1 FEC: <Root=Root-1, <opaque-value =S1,G1>>

This process allows all multicast services to work over inter-AS networks.

Supported recursive opaque values

A recursive FEC is built using the Recursive Opaque Value (opaque value 7). All non-recursive opaque values can be recursively embedded into a recursive opaque.

Opaque types lists the supported opaque values for the 7705 SAR.

Table 1. Opaque types

Opaque

Type

Opaque Name

RFC

7705 SAR Use

FEC Representation

1

Generic LSP Identifier

RFC 6388

VPRN Local AS

<Root, Opaque<P2MPID>>

7

Recursive

Opaque Value

RFC 6512

Inter-AS Option C MVPN over mLDP

<ASBR, Opaque<Root, Opaque<P2MPID>>>

Redundancy and resiliency

For mLDP, MoFRR is only supported within a single AS. In an inter-area Option C scenario, MoFRR is not supported end-to-end with PEs crossing ASBR boundaries.

Figure 6. ASBRs using EBGP without IGP
ASBR physical connection

Non-segmented mLDP functions with ASBRs directly connected or connected via an IGP domain, as shown in ASBRs using EBGP without IGP.

OAM

LSPs are unidirectional tunnels. When an LSP ping is sent, the echo request is transmitted via the tunnel and the echo response is transmitted as an IP packet to the source. Similarly, for a p2mp-lsp-ping, on the root, the echo request is transmitted via the mLDP point-to-multipoint tunnel to all leafs and the leafs use the IP packet to respond to the root.

The echo request for mLDP is generated carrying a root Target FEC Stack TLV (see ECHO request target FEC stack TLV), which is used to identify the multicast point-to-multipoint LSP under test at the leaf. The Target FEC Stack TLV must carry an mLDP point-to-multipoint FEC Stack Sub-TLV from RFC 6388 or RFC 6512.

Figure 7. ECHO request target FEC stack TLV

The same concept applies to inter-AS and non-segmented mLDP. The leafs in the remote AS should be able to resolve the root via GRT routing. This is possible for inter-AS Option C where the root is usually in the leaf RTM, which is a next-hop ASBR.

OAM functionality for Option C is summarized in OAM functionality for Option C.

Table 2. OAM functionality for Option C

OAM command (for mLDP)

Leaf and root in same AS

Leaf and root in different AS (Option C)

p2mp-lsp-ping ldp

ECMP support

In ECMP support, the leaf discovers ROOT-1 from all three ASBRs (ASBR-3, ASBR-4 and ASBR-5).

Figure 8. ECMP support

The leaf chooses which ASBR is used for the multicast stream using the following process.

  1. The leaf determines the number of ASBRs that should be part of the hash calculation.

    The number of ASBRs that are part of the hash calculation comes from the ECMP value (configured with the config>router>ecmp command). For example, if the ECMP value is set to 2, only two of the ASBRs are part of the hash algorithm selection.

  2. After selecting the upstream ASBR, the leaf determines whether there are multiple equal cost paths between it and the chosen ASBR.

    • If there are multiple ECMP paths between the leaf and the ASBR, the leaf performs another ECMP selection based on the configured ECMP value. This is a recursive ECMP lookup.

    • The first lookup chooses the ASBR and the second lookup chooses the path to that ASBR.

    For example, if ASBR 5 was chosen in ECMP support, there are three paths between the leaf and ASBR-5. A second ECMP decision is therefore made to choose the path.

  3. At ASBR-5, the process is repeated. For example, in ECMP support, ASBR-5 goes through steps 1 and 2 to choose between ASBR-1 and ASBR-2 and perform a second recursive ECMP lookup to choose the path to that ASBR.

When there are several candidate upstream LSRs, the LSR must select one upstream LSR. The algorithm used for the LSR selection is a local decision. If the LSR selection is done over a LAN interface, the procedure described in ECMP hash algorithm should be applied to ensure that the same upstream LSR is elected from the set of candidate receivers on that LAN.

The ECMP hash algorithm ensures that there is a single forwarder over the LAN for a particular LSP.

ECMP hash algorithm

The ECMP hash algorithm requires the opaque value of the FEC (see Opaque types) and is based on RFC 6388 section 2.4.1.1.

The following hash is performed: H = (CRC32 (Opaque Value)) modulo N, where N is the number of upstream LSRs. The Opaque Value is the field identified in the FEC element after Opaque Length. The Opaque Length field indicates the size of the opaque value used in this calculation.

The candidate upstream LSRs are numbered from lowest to highest IP addresses. The selected upstream LSR is the LSR that has the value H, as calculated by the hash algorithm.

Intra-AS non-segmented mLDP

Non-segmented mLDP intra-AS (inter-area) is supported on Option C only. Intra-AS non-segmented Topology shows a typical intra-AS topology with a backbone IGP area 0 and access non-backbone IGP areas 1 and 2. In these topologies, the ABRs usually do a next-hop-self for BGP label routes, which requires recursive FEC.

Figure 9. Intra-AS non-segmented Topology

ABR MoFRR for intra-AS

With ABR multicast-only fast reroute (MoFRR) in the intra-AS environment, the leaf chooses a local primary ABR and a backup ABR, with separate mLDP signaling toward these two ABRs. In addition, each path from a leaf to the primary ABR and from a leaf to the backup ABR supports IGP MoFRR.

End-to End Intra-AS MoFRR is not supported, and stops at each IGP instance. MoFRR stops at the ABR if the ABR has a leaf.

Interaction with an inter-AS non-segmented mLDP solution

Intra-AS option C is supported in conjunction with inter-AS option C. Intra-AS option C with inter-AS option B is not supported.

Multicast LDP fast upstream switchover

This feature allows a downstream LSR of a multicast LDP (mLDP) FEC to perform a fast switchover to source the traffic from another upstream LSR while IGP and LDP are converging because of a failure of the upstream LSR, where the upstream LSR is the primary next hop of the root LSR for the point-to-multipoint FEC. The feature is enabled using the mcast-upstream-frr command.

The feature provides upstream fast reroute (FRR) node protection for mLDP FEC packets. The protection is at the expense of traffic duplication from two different upstream nodes into the node that performs the fast upstream switchover.

The detailed procedures for this feature are described in draft-pdutta-mpls-mldp-up-redundancy.

mLDP Fast upstream switchover configuration

To enable the mLDP fast upstream switchover feature, configure the following option in the CLI:

config>router>ldp>mcast-upstream-frr

When mcast-upstream-frr is enabled and LDP is resolving an mLDP FEC received from a downstream LSR, LDP checks for the existence of an ECMP next hop or a loop-free alternate (LFA) next hop to the root LSR node. If LDP finds one, it programs a primary incoming label map (ILM) on the interface corresponding to the primary next hop and a backup ILM on the interface corresponding to the ECMP or LFA next hop. LDP then sends the corresponding labels to both upstream LSR nodes. In normal operation, the primary ILM accepts packets and the backup ILM drops them. If the interface or the upstream LSR of the primary ILM goes down, causing the LDP session to go down, the backup ILM starts accepting packets.

To use the ECMP next hop, configure the ecmp max-ecmp-routes value in the system to be at least 2, using the following command:

config>router>ecmp max-ecmp-routes

To use the LFA next hop, enable LFA using the following commands (as needed):

config>router>isis>loopfree-alternates

or

config>router>ospf>loopfree-alternates

Enabling IP FRR or LDP FRR is not strictly required, because LDP only needs to know the location of the alternate next hop to the root LSR to send the label mapping message and program the backup ILM during the initial signaling of the tree. That is, enabling the LFA option is sufficient for providing the backup ILM information. However, if unicast IP and LDP prefixes need to be protected, then IP FRR and LDP FRR—and the mLDP fast upstream switchover—can be enabled concurrently using the following commands:

config>router>ip-fast-reroute

or

config>router>ldp>fast-reroute

An mLDP FRR fast switchover relies on the fast detection of a lost LDP session to the upstream peer to which the primary ILM label had been advertised. To ensure fast detection of a lost LDP session, do the following:

  1. Enable BFD on all LDP interfaces to upstream LSR nodes. When BFD detects the loss of the last adjacency to the upstream LSR, it brings down the LDP session immediately, which causes the CSM to activate the backup ILM.

  2. If there is a concurrent T-LDP adjacency to the same upstream LSR node, enable BFD on the T-LDP peer in addition to enabling it on the interface.

  3. Enable the ldp-sync-timer option on all interfaces to the upstream LSR nodes. If an LDP session to the upstream LSR to which the primary ILM is resolved goes down for any reason other than a failure of the interface or the upstream LSR, then routing and LDP go out of synchronization. This means that the backup ILM remains activated until the next time SPF is run by IGP.

    By enabling the IGP-LDP synchronization feature, the advertised link metric changes to the maximum value as soon as the LDP session goes down. This, in turn, triggers an SPF, and LDP likely downloads a new set of primary and backup ILMs.

mLDP Fast upstream switchover behavior

This feature allows a downstream LSR to send a label binding to two upstream LSR nodes, but only accept traffic as follows:

  • for normal operation, traffic is accepted from the ILM on the interface to the primary next hop of the root LSR for the point-to-multipoint FEC

  • for failure operation, traffic is accepted from the ILM on the interface to the backup next hop

A candidate upstream LSR node must be either an ECMP next hop or an LFA next hop. Either option allows the downstream LSR to perform a fast switchover and to source the traffic from another upstream LSR while IGP is converging because of a failure of the LDP session of the upstream peer, which is the primary next hop of the root LSR for the point-to-multipoint FEC. That is, the candidate upstream LSR node provides upstream FRR node protection for the mLDP FEC packets.

Multicast LDP fast upstream switchover is illustrated in Multicast LDP fast upstream switchover. LSR U is the primary next hop for the root LSR R of the point-to-multipoint FEC. LSR U' is an ECMP or LFA backup next hop for the root LSR R of the same point-to-multipoint FEC.

Figure 10. Multicast LDP fast upstream switchover

In Multicast LDP fast upstream switchover, downstream LSR Z sends a label mapping message to both upstream LSR nodes, and programs the primary ILM on the interface to LSR U and the backup ILM on the interface to LSR U'. The labels for the primary and backup ILMs must be different. Thus LSR Z attracts traffic from both ILMs. However, LSR Z blocks the ILM on the interface to LSR U' and only accepts traffic from the ILM on the interface to LSR U.

If the link to LSR U fails, or LSR U fails, causing the LDP session to LSR U to go down, LSR Z detects the failure and reverse the ILM blocking state. In addition, LSR Z immediately starts receiving traffic from LSR U' until IGP converges and provides a new primary next hop and a new ECMP or LFA backup next hop, which may or may not be on the interface to LSR U'. When IGP convergence is complete, LSR Z updates the primary and backup ILMs in the datapath.

Note: LDP uses the interface of either an ECMP next hop or an LFA next hop to the root LSR prefix, whichever is available, to program the backup ILM. However, ECMP next hop and LFA next hop are mutually exclusive for a specific prefix. IGP installs the ECMP next hop in preference to the LFA next hop as a prefix in the routing table manager (RTM).

If one or more ECMP next hops for the root LSR prefix exist, LDP picks the interface for the primary ILM based on the rules of mLDP FEC resolution specified in RFC 6388, Label Distribution Protocol Extensions for Point-to-Multipoint and Multipoint-to-Multipoint Label Switched Paths:

  1. The candidate upstream LSRs are numbered from lowest to highest IP address.

  2. The following hash is performed:

    H = (CRC32(Opaque Value)) modulo N

    where N is the number of upstream LSRs

    The Opaque Value is the field in the point-to-multipoint FEC element immediately after the Opaque Length field. The Opaque Length indicates the opaque value used in this calculation.

  3. The selected upstream LSR U is the LSR that has the number H.

LDP then picks the interface for the backup ILM using the following new rules:

if (H + 1 < NUM_ECMP) {

// If the hashed entry is not last in the next hops then pick up the next as backup.

backup = H + 1;

} else {

// Wrap around and pick up the first.

backup = 1;

}

In some topologies, it is possible that no ECMP or LFA next hop is found. In this case, LDP programs the primary ILM only.

LDP IPv6

The 7705 SAR extends the LDP control plane and data plane to support LDP IPv6 adjacencies and sessions using 128-bit LSR ID.

The implementation allows for concurrent support of independent LDP IPv4 (which uses a 32-bit LSR ID) and LDP IPv6 adjacencies and sessions between peer LSRs and over the same interfaces or different set of interfaces.

LDP adjacency and session over an IPv6 interface shows an example of an LDP adjacency and session over an IPv6 interface.

Figure 11. LDP adjacency and session over an IPv6 interface

LSR-A and LSR-B have the following IPv6 LDP identifiers respectively:

  • <LSR Id=A/128> : <label space id=0>

  • <LSR Id=B/128> : <label space id=0>

By default, LSR-A/128 and LSR-B/128 use the system interface IPv6 address.

Although the LDP control plane can operate using only the IPv6 system address, it is recommended that the user must configure the IPv4-formatted router ID in order for OSPF, IS-IS, and BGP to operate properly.

The following sections describe LDP IPv6 behavior on the 7705 SAR:

Link LDP

LDP IPv6 uses a 128-bit LSR ID as defined in draft- pdutta-mpls-ldp-v2-00. See LDP process overview for more information about interoperability of this implementation with a 32-bit LSR ID, as defined in draft-ietf- mpls-ldp-ipv6-14.

A Hello adjacency is brought up using a link Hello packet with a source IP address set to the interface link local unicast address and a destination IP address set to the link local multicast address FF02:0:0:0:0:0:0:2.

The transport address for the TCP connection, which is encoded in the Hello packet, is set by default to the LSR ID of the LSR. The transport address is instead set to the interface IPv6 address if the user enables the interface option in one of the following contexts:

  • config>router>ldp>if-params>ipv6>transport-address

  • config>router>ldp>if-params>if>ipv6>transport-address

The user can configure the local-lsr-id option on the interface and change the value of the LSR ID to either the local interface or to another interface name, including loopback. The global unicast IPv6 address corresponding to the primary IPv6 address of the interface is used as the LSR ID. If the interface does not have a global unicast IPv6 address in the configuration of the transport address or the configuration of the local-lsr-id option, the session does not come up and an error message is displayed.

The LSR with the highest transport address bootstraps the IPv6 TCP connection and IPv6 LDP session.

The source and destination addresses of LDP/TCP session packets are the IPv6 transport addresses.

Targeted LDP

The source and destination addresses of targeted Hello packets are the LDP IPv6 LSR- IDs of systems A and B in LDP adjacency and session over an IPv6 interface.

The user can configure the local-lsr-id option on the targeted session and change the value of the LSR ID to either the local interface or to some other interface name, including loopback or not. The global unicast IPv6 address corresponding to the primary IPv6 address of the interface is used as the LSR ID. If the user invokes an interface that does not have a global unicast IPv6 address in the configuration of the transport address or the configuration of the local-lsr-id option, the session does not come up and an error message is displayed. In all cases, the transport address for the LDP session and the source IP address of targeted Hello messages are updated with the new LSR ID value.

The LSR with the highest transport address (in this case, the LSR ID) bootstraps the IPv6 TCP connection and IPv6 LDP session.

The source and destination IP addresses of LDP/TCP session packets are the IPv6 transport addresses the LDP LSR IDs of systems A and B in LDP adjacency and session over an IPv6 interface.

FEC resolution

LDP advertises and withdraws all interface IPv6 addresses using the Address/ Address-Withdraw message. Both the link local unicast address and the configured global unicast addresses of an interface are advertised.

Like LDP IPv4 sessions, LDP FEC types can be exchanged over an LDP IPv6 session. The LSR does not advertise a FEC for a link local address and, if received, the LSR does not resolve it.

An IPv4 or IPv6 prefix FEC can be resolved to an LDP IPv6 interface in the same way it is resolved to an LDP IPv4 interface. The outgoing interface and next hop are looked up in the RTM cache. The next hop can be the link local unicast address of the other side of the link or a global unicast address. The FEC is resolved to the LDP IPv6 interface of the downstream LDP IPv6 LSR that advertised the IPv4 or IPv6 address of the next hop.

A PW FEC can be resolved to a targeted LDP IPv6 adjacency with an LDP IPv6 LSR if there is a context for the FEC with local spoke SDP configuration or spoke SDP auto-creation from a service such as BGP-AD VPLS, BGP-VPWS, or dynamic MS- PW.

LDP session capabilities

LDP can advertise all FEC types over an LDP IPv4 or an LDP IPv6 session. The FEC types are: IPv4 prefix FEC, IPv6 prefix FEC, IPv4 P2MP FEC (with MVPN), and PW FEC 128.

LDP also supports signaling the enabling or disabling of the advertisement of the following subset of FEC types during the LDP IPv4 or IPv6 session initialization phase, and when the session is already up.

  • IPv4 prefix FEC

    This is performed using the State Advertisement Control (SAC) capability TLV as specified in draft-ietf-mpls-ldp-ip-pw-capability. The SAC capability TLV includes the IPv4 SAC element having the D-bit (Disable- bit) set or reset to disable or enable this FEC type respectively. The LSR can send this TLV in the LDP Initialization message and subsequently in an LDP capability message.

  • IPv6 prefix FEC

    This is performed using the State Advertisement Control (SAC) capability TLV as specified in draft-ietf-mpls-ldp-ip-pw-capability. The SAC capability TLV includes the IPv6 SAC element having the D-bit (Disable- bit) set or reset to disable or enable this FEC type respectively. The LSR can send this TLV in the LDP Initialization message and subsequently in an LDP capability message to update the state of this FEC type.

  • P2MP FEC (IPv4 only)

    This is performed using the P2MP capability TLV as specified in RFC 6388. The P2MP capability TLV has the S-bit (State-bit) with a value of set or reset to enable or disable this FEC type respectively. The LSR can send this TLV in the LDP initialization message and, subsequently, in an LDP capability message to update the state of this FEC type.

During LDP session initialization, each LSR indicates to its peers which FEC type it supports by including the capability TLV for it in the LDP initialization message. The 7705 SAR enables the IPv4 and IPv6 Prefix FEC types by default and sends their corresponding capability TLVs in the LDP initialization message. If one or both peers advertise the disabling of a capability in the LDP Initialization message, no FECs of the corresponding FEC type are exchanged between the two peers for the lifetime of the LDP session unless a capability message is sent to explicitly enable it. The same behavior applies if no capability TLV for a FEC type is advertised in the LDP initialization message, except for the IPv4 prefix FEC which is assumed to be supported by all implementations by default.

Dynamic Capability, as defined in RFC 5561, allows all FEC types to update the enabled or disabled state after the LDP session initialization phase. An LSR informs its peer that it supports Dynamic Capability by including the Dynamic Capability Announcement TLV in the LDP initialization message. If both LSRs advertise this capability, the user can enable or disable any of the above FEC types while the session is up and the change takes effect immediately. The LSR then sends a SAC capability message with the IPv4 or IPv6 SAC element having the D-bit (Disable-bit) set or reset, or the P2MP capability TLV (IPv4 only) in a capability message with the S-bit (State-bit) set or reset. Each LSR then takes the consequent action of withdrawing or advertising the FECs of that type to the peer LSR. If one or both LSRs did not advertise the Dynamic Capability Announcement TLV in the LDP initialization message, any change to the enabled or disabled FEC types only takes effect the next time the LDP session is restarted.

The user can enable or disable a specific FEC type for a specific LDP session to a peer by using the following CLI commands:

  • config>router>ldp>session-params>peer>fec-type-capability>prefix-ipv4

  • config>router>ldp>session-params>peer>fec-type-capability>prefix-ipv6

  • config>router>ldp>session-params>peer>fec-type-capability>p2mp

LDP adjacency capabilities

Adjacency-level FEC-type capability advertisement is defined in draft-pdutta-mpls- ldp-adj-capability. By default, all FEC types supported by the LSR are advertised in the LDP IPv4 or IPv6 session initialization; see LDP session capabilities for more information. If a specific FEC type is enabled at the session level, it can be disabled over a specified LDP interface at the IPv4 or IPv6 adjacency level for all IPv4 or IPv6 peers over that interface. If a specific FEC type is disabled at the session level, then FECs are not advertised and enabling that FEC type at the adjacency level do not have any effect. The LDP adjacency capability can be configured on link Hello adjacency only and does not apply to targeted Hello adjacency.

The LDP adjacency capability TLV is advertised in the Hello message with the D-bit (Disable-bit) set or reset to disable or enable the resolution of this FEC type over the link of the Hello adjacency. It is used to restrict which FECs can be resolved over a specified interface to a peer. This provides the ability to dedicate links and data path resources to specific FEC types. For IPv4 and IPv6 prefix FECs, a subset of ECMP links to an LSR peer may be configured to carry one of the two FEC types. An mLDP P2MP FEC (IPv4 only) can exclude specific links to a downstream LSR from being used to resolve this type of FEC.

Like the LDP session-level FEC-type capability, the adjacency FEC-type capability is negotiated for both directions of the adjacency. If one or both peers advertise the disabling of a capability in the LDP Hello message, no FECs of the corresponding FEC type is resolved by either peer over the link of this adjacency for the lifetime of the LDP Hello adjacency, unless one or both peers sends the LDP adjacency capability TLV subsequently to explicitly enable it.

The user can enable or disable an FEC type for a specific LDP interface to a peer by using the following CLI commands:

  • config>router>ldp>if-params>if>ipv4>fec-type-capability>p2mp-ipv4

  • config>router>ldp>if-params>if>ipv4/ipv6>fec-type-capability>prefix-ipv4

  • config>router>ldp>if-params>if> ipv4/ipv6>fec-type-capability>prefix-ipv6

These commands, when applied to the IPv4 P2MP FEC, deprecate the existing multicast-traffic command under the interface. Unlike the session-level capability, these commands can disable multicast FEC for IPv4.

The encoding of the adjacency capability TLV uses a PRIVATE Vendor TLV. It is used only in a Hello message to negotiate a set of capabilities for a specific LDP IPv4 or IPv6 hello adjacency.

0                   1                   2                   3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|1|0| ADJ_CAPABILITY_TLV       |      Length                    |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                    VENDOR_OUI                                 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|S| Reserved  |                                                 |
+-+-+-+-+-+-+-+-+                                               +
|          Adjacency capability elements                        |
+                                                               +
|                                                               |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

The value of the U-bit for the TLV is set to 1 so that a receiver must silently ignore if the TLV is deemed unknown.

The value of the F-bit is 0. After being advertised, this capability cannot be withdrawn; therefore, the S-bit is set to 1 in a Hello message.

Adjacency capability elements are encoded as follows:

0 1 2 3 4 5 6 7 
+-+-+-+-+-+-+-+-+
|D| CapFlag     |
+-+-+-+-+-+-+-+-+

D bit: Controls the capability state.

  • 1 : Disable capability

  • 0 : Enable capability

CapFlag: The adjacency capability

  • 1 : Prefix IPv4 forwarding

  • 2 : Prefix IPv6 forwarding

  • 3 : P2MP IPv4 forwarding

  • 4 : P2MP IPv6 forwarding (not supported on the 7705 SAR)

  • 5 : MP2MP IPv4 forwarding

  • 6 : MP2MP IPv6 forwarding

Each CapFlag appears no more than once in the TLV. If duplicates are found, the D-bit of the first element is used. For forward compatibility, if the CapFlag is unknown, the receiver must silently discard the element and continue processing the rest of the TLV.

IP address and FEC distribution

When an LDP LSR initializes the LDP session to the peer LSR and the session comes up, IP addresses and FECs are distributed. Local IPv4 and IPv6 interface addresses are exchanged using the Address and Address Withdraw messages. FECs are exchanged using label mapping messages.

By default, IPv6 address distribution is determined by whether the dual-stack capability TLV, which is defined in draft-ietf-mpls-ldp-ipv6, is present in the Hello message from the peer. This requirement is designed to address interoperability issues found with existing third-party LDP IPv4 implementations.

IP address and FEC distribution behavior is described below.

  • If the peer LSR sent the dual-stack capability TLV in the Hello message, then local IPv6 addresses are sent to the peer. The user can configure an address export policy to restrict which local IPv6 interface addresses are sent to the peer.

    • If the peer explicitly stated enabling of LDP IPv6 FEC type by including the IPv6 SAC TLV in the initialization message with the D-bit set to 0, then IPv6 FECs are also sent to the peer.

    • If the peer sent the dual-stack capability TLV in the Hello message, but explicitly stated disabling of LDP IPv6 FEC type by including the IPv6 SAC TLV in the initialization message with the D-bit set to 1, then IPv6 local addresses instead of IPv6 FECs are sent to the peer. The user can configure an address export policy to further restrict which local IPv6 interface addresses to send to the peer.

  • If the peer did not send the dual-stack capability TLV in the Hello message, then no IPv6 addresses or IPv6 FECs are sent to that peer, regardless of the presence or not of the IPv6 SAC TLV in the initialization message. This case is added to prevent interoperability issues with some third-party LDP IPv4 implementations. The user can override the distribution defined by the initial Hello message by explicitly configuring an address export policy and a FEC export policy to select IPv6 addresses and FECs to send to the peer.

The above behavior applies to LDP IPv4 and IPv6 addresses and FECs. The procedure is summarized in the flowchart diagrams in LDP IPv6 address and FEC distribution procedure and LDP IPv6 address and FEC distribution procedure.

Figure 12. LDP IPv6 address and FEC distribution procedure
Figure 13. LDP IPv6 address and FEC distribution procedure

IGP and static route synchronization with LDP

The IGP-LDP synchronization and the static route-to-LDP synchronization features are modified to operate on a dual-stack IPv4 or IPv6 LDP interface as follows.

  • If the router interface goes down or both LDP IPv4 and LDP IPv6 sessions go down, IGP sets the interface metric to the maximum value and all static routes with the ldp-sync option enabled and resolved on this interface are deactivated.

  • If the router interface is up and only one of the LDP IPv4 or LDP IPv6 interfaces goes down, no action is taken.

  • When the router interface comes up from a down state, and the LDP IPv4 or LDP IPv6 sessions comes up, IGP starts the sync timer. When the sync timer expires, the interface metric is restored to its configured value and all static routes with the ldp-sync option enabled are activated.

Given the above behavior, it is recommended that the user configures the sync timer to a value that allows enough time for both the LDP IPv4 and LDP IPv6 sessions to come up.

BFD operation

The operation of BFD over an LDP interface tracks the next hop of prefix IPv4 and prefix IPv6 in addition to tracking of the LDP peer address of the Hello adjacency over that link. Tracking is required because LDP can resolve both IPv4 and IPv6 prefix FECs over a single IPv4 or IPv6 LDP session and therefore, the next hop of a prefix does not necessarily match the LDP peer source address of the Hello adjacency. If any of the BFD tracking sessions fail, the LFA backup NHLFE for the FEC is activated, or, if there is no FRR backup, the FEC is re-resolved.

The user can configure tracking with only an IPv4 BFD session, only an IPv6 BFD session, or with both using the config>router>ldp>if-params>if>bfd-enable [ipv4] [ipv6] command.

This command provides flexibility in case the user does not need to track both Hello adjacency and the next hops of FECs.

For example, if the user configures bfd-enable ipv6 only to save on the number of BFD sessions, then LDP tracks the IPv6 Hello adjacency and the next hops of IPv6 prefix FECs. LDP does not track next hops of IPv4 prefix FECs resolved over the same LDP IPv6 adjacency. If the IPv4 data plane encounters errors and the IPv6 Hello adjacency is not affected and remains up, traffic for the IPv4 prefix FECs resolved over that IPv6 adjacency is blackholed. If the BFD tracking the IPv6 Hello adjacency times out, then all IPv4 and IPv6 prefix FECs are updated.

Services using SDP with an LDP IPv6 FEC

The 7705 SAR supports SDPs of type LDP with far-end options using IPv6 addresses. The addresses need not be of the same family (IPv6 or IPv4) for the SDP configuration to be allowed. The user can have an SDP with an IPv4 (or IPv6) control plane for the T-LDP session and an IPv6 (or IPv4) LDP FEC as the tunnel.

Because IPv6 LSP is only supported with LDP, the use of a far-end IPv6 address is not allowed with a BGP or RSVP/MPLS LSP. In addition, the CLI does not allow an SDP with a combination of an IPv6 LDP LSP and an IPv4 LSP of a different control plane. As a result, the following commands are blocked in the SDP configuration context when the far end is an IPv6 address:

  • bgp-tunnel

  • lsp

  • mixed-lsp-mode

SDP admin groups are not supported with an SDP using an LDP IPv6 FEC, and the attempt to assign them is blocked in CLI.

Services that use the LDP control plane (such as T-LDP VPLS and R-VPLS, VLL, and IES/VPRN spoke interface) have the spoke SDP (PW) signaled with an IPv6 T-LDP session when the far-end option is configured to an IPv6 address. By default, the spoke SDP for these services binds to an SDP that uses an LDP IPv6 FEC that matches the prefix of the far end address.

In addition, the IPv6 PW control word is supported with data plane packets and VCCV OAM packets. Hash label is also supported with the above services, including the signaling and negotiation of hash label support using T-LDP (Flow sub-TLV) with the LDP IPv6 control plane. Finally, network domains are supported in VPLS.

Mirror services

The user can configure a spoke SDP bound to an LDP IPv6 LSP to forward mirrored packets from a mirror source to a remote mirror destination. In the configuration of the mirror destination service at the destination node, the remote-source command must use a spoke SDP with a VC ID that matches the VC-ID that is configured in the mirror destination service at the mirror source node. The far-end option is not supported with an IPv6 address.

Configuration at mirror source node

Use the following rules and syntax to configure a spoke SDP at the mirror source node.

  • The sdp-id must match an SDP that uses an LDP IPv6 FEC.

  • Configuring the egress-vc-label is optional.

CLI syntax:
no spoke-sdp sdp-id:vc-id
spoke-sdp sdp-id:vc-id [create] egress
vc-label egress-vc-label

Configuration at mirror destination node

Use the following rules and syntax to configure mirror service at the mirror destination node.

  • The far-end ip-address command is not supported with LDP IPv6 transport tunnel. The user must reference a spoke SDP using an LDP IPv6 SDP coming from mirror source node.

  • In the spoke-sdp sdp-id:vc-id command, the vc-id should match that of the spoke-sdp configured in the mirror-destination context at the mirror source node.

  • Configuring the ingress-vc-label is optional; both Static and T-LDP are supported.

CLI syntax:
far-end ip-address [vc-id vc-id] [ing-svc-label ingress- vc-label | tldp] [icb]
no far-end ip-address
spoke-sdp sdp-id:vc-id [create] ingress-vc-label ingress-vc-label exit
no shutdown exit
exit

Mirroring is also supported with the PW redundancy feature when the endpoint spoke SDP, including the ICB, is using an LDP IPv6 tunnel.

OAM support with LDP IPv6

MPLS OAM tools LSP ping and LSP trace can operate with LDP IPv6 and support the following:

  • use of IPv6 addresses in the echo request and echo reply messages, including in DSMAP TLV, as per RFC 4379

  • use of LDP IPv6 prefix target FEC stack TLV, as per RFC 4379

  • use of IPv6 addresses in the DDMAP TLV and FEC stack change sub-TLV, as per RFC 6424

  • use of 127/8 IPv4 mapped IPv6 address; that is, in the range ::ffff:127/104, as the destination address of the echo request message, as per RFC 4379

  • use of 127/8 IPv4 mapped IPv6 address; that is, in the range ::ffff:127/104, as the path-destination address when the user wants to exercise a specific LDP ECMP path

The behavior at the sender and receiver nodes supports both LDP IPv4 and IPv6 target FEC stack TLVs. Specifically:

  • The IP family (IPv4/IPv6) of the UDP/IP echo request message always matches the family of the LDP target FEC stack TLV as entered by the user in the prefix option.

  • The src-ip-address option is extended to accept IPv6 address of the sender node. If the user did not enter a source IP address, the system IPv6 address is used. If the user entered a source IP address of a different family than the LDP target FEC stack TLV, an error is returned and the command is aborted.

  • The IP family of the UDP/IP echo reply message must match that of the received echo request message.

  • For lsp-trace, the downstream information in DSMAP/DDMAP is encoded as the same family as the LDP control plane of the link LDP or targeted LDP session to the downstream peer.

  • The sender node inserts the experimental value of 65503 in the Router Alert Option in the echo request packet IPv6 header, as per RFC 5350. After a value is allocated by IANA for MPLS OAM as part of draft-ietf-mpls-oam-ipv6-rao, it is updated.

VCCV ping and VCCV trace for a single-hop PW support IPv6 PW FEC 128, as per RFC 6829. In addition, the PW OAM control word is supported with VCCV packets when the control-word option is enabled on the spoke SDP configuration. When the value of the Channel Type field is set to 0x57, it indicates that the Associated Channel carries an IPv6 packet, as per RFC 4385.

Interoperability

Interoperability with implementations compliant with draft- ietf-mpls-ldp-ipv6

The 7705 SAR uses a 128-bit LSR ID as defined in draft-pdutta-mpls-ldp-v2 to establish an LDP IPv6 session with a peer LSR. This is so that a routable system IPv6 address can be used by default to bring up the LDP task on the router and establish link LDP and T-LDP sessions to other LSRs. More importantly, using a 128-bit LSR ID allows for the establishment of control plane-independent LDP IPv4 and IPv6 sessions between two LSRs over the same interface or different set of interfaces because each session uses a unique LSR ID (32-bit for IPv4 and 128-bit for IPv6).

The 7705 SAR LDP implementation does not interoperate with a system using a 32-bit LSR ID (as defined in draft-ietf-mpls-ldp-ipv6) to establish an IPv6 LDP session. The latter specifies that an LSR can send both IPv4 and IPv6 Hello messages over an interface, allowing the system to establish either an IPv4 or an IPv6 LDP session with LSRs on the same subnet. It does not allow for separate LDP IPv4 and LDP IPv6 LDP sessions between two routers.

The 7705 SAR LDP implementation interoperates with systems using a 32-bit LSR ID (as defined in draft-ietf-mpls-ldp-ipv6) to establish an IPv4 LDP session and to resolve both IPv4 and IPv6 prefix FECs.

The 7705 SAR otherwise complies with all other aspects of draft-ietf-mpls-ldp-ipv6, including the support of the dual-stack capability TLV in the Hello message. The latter is used by an LSR to inform its peer that it is capable of establishing either an LDP IPv4 or LDP IPv6 session and to convey the IP family preference for the LDP Hello adjacency and thus for the resulting LDP session. This is required because the implementation described in draft-ietf-mpls-ldp-ipv6 allows for a single session between LSRs, and both LSRs must agree if the session should be brought up using IPv4 or IPv6 when both IPv4 and IPv6 Hellos are exchanged between the two LSRs. The 7705 SAR implementation has a separate session for each IP family between two LSRs and, as such, this TLV is used to specify the family preference and to indicate that the system supports resolving IPv6 FECs over an IPv4 LDP session.

Interoperability with implementations compliant with RFC 5036 for IPv4 LDP control plane only

Some third-party LDP implementations are compliant with RFC 5036 for LDP IPv4 but are not compliant with RFC 5036 for handling IPv6 address or IPv6 FECs over an LDP IPv4 session.

An LSR based on the 7705 SAR in a LAN with a broadcast interface can peer with any third-party LSR, including those that are incapable of handling IPv6 address or IPv6 FECs over an LDP IPv4 session. When the 7705 SAR uses the IPv4 LDP control plane to advertise IPv6 addresses or IPv6 FECs to that peer, it can cause the IPv4 LDP session to go down.

To address this issue, draft-ietf-mpls-ldp-ipv6 modifies RFC 5036 and requires compliant systems to check for the dual-stack capability TLV in the IPv4 Hello message from the peer. If the peer does not advertise this TLV, the LSR does not send IPv6 addresses and FECs to that peer. The 7705 SAR supports advertising and resolving IPv6 prefix FECs over an LDP IPv4 session using a 32-bit LSR ID in compliance with draft-ietf-mpls-ldp-ipv6.

Upgrading from IPv4 to IPv6

For smooth transition from IPv4 to IPv6, it is recommended to follow the steps below.

  1. Create a new IPv6 interface in the 7750 SR management VPRN.

  2. Configure a new Layer 3 Spoke SDP configured with LDPv6 and a far-end IPv6 address, and assign it to the new IPv6 interface.

  3. On the 7705 SAR, in the management Epipe create an endpoint object and assign the endpoint to the existing IPv4 PW. Ensure there is no traffic lost during this step.

  4. On the 7705 SAR, create a new SDP with LDPv6 and a far-end IPv6 address.

  5. On the 7705 SAR, within the management Epipe, assign the new SDP to a spoke SDP with the same endpoint as the IPv4 spoke SDP.

  6. On the 7750 SAR, shut down the IPv4 interface.

  7. On the 7705 SAR, start IPv6 traffic and ensure reachability to 7705 via the IPv6 SDP.

  8. Remove the IPv4 SDP and spokes from the 7705 SAR Epipe and 7750 SR VPRN.

Smooth management transition from IPv4 to IPv6 shows an example of a network ensuring a smooth upgrade from IPv4 to IPv6 with PW redundancy.

Figure 14. Smooth management transition from IPv4 to IPv6

Configuration notes

See the 7705 SAR Services Guide for information about signaling.

LDP configuration overview

When the 7705 SAR implementation of LDP is instantiated, the protocol is in the no shutdown state. In addition, targeted sessions are then enabled. The default parameters for LDP are set to the documented values for targeted sessions in draft-ietf-mpls-ldp-mib-09.txt.

LDP must be enabled in order for signaling to be used to obtain the ingress and egress labels in frames transmitted and received on the service destination point (SDP). When signaling is off, labels must be manually configured when the SDP is bound to a service.

Basic LDP configuration

This section provides information to configure LDP and gives configuration examples of common configuration tasks.

The LDP protocol instance is created in the no shutdown (enabled) state.

The following example displays the default LDP configuration output.

ALU-1>config>router>ldp# info 
----------------------------------------------
            interface-parameters
            exit
            targeted-session
            exit
----------------------------------------------
ALU-1>config>router>ldp#

Common configuration tasks

Enabling LDP

LDP must be enabled in order for the protocol to be active. MPLS must also be enabled. MPLS is enabled in the config>router>mpls context.

Use the following CLI syntax to enable LDP on a 7705 SAR router:

CLI syntax:
ldp
Example:
config>router# ldp

The following example displays the enabled LDP configuration output.

ALU-1>config>router# info
----------------------------------------------
...
#------------------------------------------
echo "LDP Configuration"
#------------------------------------------
        ldp
            interface-parameters
            exit
            targeted-session
            exit
        exit
----------------------------------------------
...
ALU-1>config>router#

Configuring Graceful Restart Helper parameters

Graceful Restart Helper advertises to its LDP neighbors by carrying the fault tolerant (FT) session TLV in the LDP initialization message, assisting the LDP in preserving its IP forwarding state across the restart. The 7705 SAR recovery is self-contained and relies on information stored internally to self-heal.

Maximum recovery time is the time (in seconds) that the sender of the TLV would like the receiver to wait, after detecting the failure of LDP communication with the sender.

Neighbor liveness time is the time (in seconds) that the LSR is willing to retain its MPLS forwarding state. The time should be long enough to allow the neighboring LSRs to resynchronize all the LSPs in a graceful manner, without creating congestion in the LDP control plane.

Use the following syntax to configure graceful restart parameters:

CLI syntax:
config>router>ldp
    [no] graceful-restart
        [no] maximum-recovery-time interval
        [no] neighbor-liveness-time interval
Example:
config>router>ldp
config>router>ldp# graceful-restart
config>router>ldp>graceful-restart# maximum-recovery-
  time 120
config>router>ldp>graceful-restart# neighbor-liveness-
  time 60
config>router>ldp# exit
config>router# 

The following example displays the import policy configuration output.

ALU-1>config>router>ldp>graceful-restart# info
----------------------------------------------
                maximum-recovery-time 120
                neighbor-liveness-time 60
----------------------------------------------
ALU-1>config>router>ldp>graceful-restart#

Applying import and export policies

Inbound filtering (import policy) allows a route policy to control the label bindings that an LSR accepts from its peers. An import policy can accept or reject label bindings received from LDP peers. Label bindings can be filtered based on the following:

  • neighbor — match on bindings received from the specified peer

  • prefix-list — match on bindings with the specified prefix or prefixes

Outbound filtering (export policy) allows a route policy to control the label bindings advertised by the LSR to its peers. Label bindings can be filtered based on the following:

  • all — all local subnets by specifying direct as the match protocol

  • prefix-list — match on bindings with the specified prefix/prefixes

Import or export policies must already exist before they are applied to LDP. Policies are configured in the config>router>policy-options context. See the ‟Route Policies” section in the 7705 SAR Router Configuration Guide for details.

Note:
  • The 7705 SAR supports a specific number of labels, which varies by platform and software release. If the number of labels is exceeded for a specific protocol (for example, LDP or RSVP), a log message will appear by default in logs 99 and 100. The log message states the affected protocol and the label count that was exceeded. For example: ‟mpls_label_ilm_helper: XXXX XXX XXXX limit reached max obj count of YYYY”.

  • For the LDP protocol, when the label count is exceeded, LDP sessions will be shut down and all labels will be removed. To recover the LDP sessions, perform a shutdown/no shutdown combination of commands in the config>router>ldp context.

Use the following CLI syntax to apply import or export policies:

CLI syntax:
config>router>ldp
    import policy-name [policy-name...(up to 5 max)]
    export policy-name [policy-name...(up to 5 max)]
Example:
config>router>ldp
config>router>ldp# import LDP-import
config>router>ldp# export LDP-export
config>router>ldp# exit
config>router# 

The following example displays the import and export policy configuration output.

ALU-1>config>router>ldp# info
----------------------------------------------
            export "LDP-export"
            import "LDP-import"
            interface-parameters
            exit
            targeted-session
            exit
----------------------------------------------

Configuring interface parameters

Use the following CLI syntax to configure LDP interface parameters:

CLI syntax:
config>router# ldp
    interface-parameters
        hello timeout factor
        interface ip-int-name
            hello timeout factor
            keepalive timeout factor
            local-lsr-id {system | interface}
            transport-address {system | interface}
              no shutdown
        keepalive timeout factor
        transport-address {system|interface}
Example:
config>router# ldp
config>router>ldp# interface-parameters
config>router>ldp>if-params# interface to-104
config>router>ldp>if-params>if# hello 15 3
config>router>ldp>if-params>if# local-lsr-id system
config>router>ldp>if-params>if# no shutdown
config>router>ldp>if-params>if# exit
config>router>ldp>if-params# exit
config>router>ldp#

The following example displays the LDP interface parameter configuration output.

ALU-1>config>router>ldp# info
----------------------------------------------
          import "LDP-import"
            interface-parameters
                hello 15 3
                keepalive 30 3
                interface "to-104"
                    hello 15 3
                    keepalive 30 3
                    local-lsr-id system
                    no shutdown
                exit
            exit
          targeted-session
          exit
          no shutdown
----------------------------------------------
ALU-1>config>router>ldp#

Specifying targeted session parameters

Use the following CLI syntax to specify targeted session parameters:

CLI syntax:
config>router# ldp
    targeted-session
        disable-targeted-session
        hello timeout factor
        keepalive timeout factor
        peer ip-address
            bfd-enable
            hello timeout factor
            keepalive timeout factor
            local-lsr-id interface-name
              no shutdown
Example:
config>router# ldp
config>router>ldp# targeted-session
config>router>ldp>targ-session# bfd-enable
config>router>ldp>targ-session# hello 5000 255
config>router>ldp>targ-session# keepalive 5000 255
config>router>ldp>targ-session# peer 10.10.10.104
config>router>ldp>targ-session>peer# hello 2500 100
config>router>ldp>targ-session>peer# keepalive 15 3
config>router>ldp>targ-session>peer# local-lsr-id to-104
config>router>ldp>targ-session>peer# no shutdown
config>router>ldp>targ-session>peer# exit
config>router>ldp>targ-session# exit
config>router>ldp# 

The following example displays the LDP targeted session configuration output.

ALU-1>config>router>ldp# info
----------------------------------------------
          import "LDP-import"
          interface-parameters
                hello 15 3
                keepalive 30 3
                interface "to-104"
                    hello 15 3
                    keepalive 30 3
                    no shutdown
                exit
          exit
            targeted-session
                hello 5000 255
                keepalive 5000 255
                peer 10.10.10.104
                    hello 2500 100
                    keepalive 15 3
                    local-lsr-id ‟to-104”
                exit
            exit
----------------------------------------------

Specifying peer parameters

Use the following CLI syntax to specify LDP peer parameters:

CLI syntax:
config>router# ldp
    peer-parameters
        peer ip-address
            auth-keychain name
            authentication-key {authentication-key | hash-key} [hash | hash2]
Example:
config>router# ldp
config>router>ldp# peer-parameters
config>router>ldp>peer-params# peer 10.10.10.104
config>router>ldp>peer-params>peer$ authentication-key
  testuser
config>router>ldp>peer-params>peer$ exit

The following example displays the LDP peer parameters configuration output.

ALU-1>config>router>ldp# info
----------------------------------------------
           import "LDP-import"
           graceful-restart
           exit
           import "LDP-import"
           peer-parameters
                peer 10.10.10.104
                    authentication-key "nGjXyHQtCgHxbBm.kDeYdzSmPZy9KK03" hash2
                exit
           exit
           interface-parameters
                interface "test"
                exit
                interface "to-104"
                    hello 15 3
                exit
           exit
           targeted-session
                hello 5000 255
                keepalive 5000 255
                peer 10.10.10.104
                    hello 2500 100
                    keepalive 15 3
                exit
           exit
----------------------------------------------
ALU-1>config>router>ldp#

Configuring LDP support for multicast VPN (MVPN)

For LDP support for MVPN, configure the multicast-traffic, mp-mbb-time, and mcast-upstream-frr commands.

The following example displays the LDP MVPN configuration output.

*A:SarAx Dut-D>config>router>ldp# info detail
----------------------------------------------
            no aggregate-prefix-match
            no export
            no fast-reroute
            no import
            no graceful-restart
            mcast-upstream-frr
            mp-mbb-time 5
            no tunnel-down-damp-time
            interface-parameters
                hello 15 3
                keepalive 30 3
                transport-address system
                interface "mcast_if"
                    no bfd-enable
                    no hello
                    no keepalive
                    no local-lsr-id
                    multicast-traffic enable
                    no transport-address
                    no shutdown
                exit
            exit
            targeted-session
                no disable-targeted-session
                hello 45 3
                keepalive 40 4
            exit
            no shutdown
----------------------------------------------
*A:SarAx Dut-D>config>router>ldp#

Configuring LDP support for LDP-to-SR stitching

Configure the export-tunnel-table command using the following CLI syntax to support LDP-to-SR stitching.

CLI syntax:
config>router# ldp
    export-tunnel-table policy-name [policy-name...(up to 5 max)]
Note: The specified policy name must be the same as the policy-statement name defined when configuring the route policy options for LDP-to-SR stitching. See the 7705 SAR Router Configuration Guide, ‟Configuring LDP-to-Segment Routing Stitching Policies”.
Example:
config>router>ldp# export-tunnel-table "export-SR"
config>router>ldp# exit

The following example displays the LDP-to-SR stitching LDP configuration output.

*A:NOK-1 Dut-B>config>router>ldp# info
----------------------------------------------
            export-tunnel-table "export-SR"
            ...
            exit
            ...
----------------------------------------------
*A:NOK-1 Dut-B>config>router>ldp#

Enabling LDP signaling and services

When LDP is enabled, targeted sessions can be established to create remote adjacencies with nodes that are not directly connected. When service destination points (SDPs) are configured, extended discovery mechanisms enable LDP to send periodic targeted hello messages to the SDP’s far-end point. The exchange of LDP hellos triggers session establishment. The SDP’s signaling default enables tldp. The SDP uses the targeted-session parameters configured in the config>router>ldp> targeted-session context.

The service>sdp>ldp and router>lsp commands are mutually exclusive; you can either specify an LSP or enable an LDP. There cannot be two methods of transport in a single SDP.

To enable LDP on the SDP when an LSP is already specified, the LSP must be removed from the configuration using the no lsp lsp-name command. For more information about configuring SDPs, see the 7705 SAR Services Guide.

Use the following CLI syntax to enable LDP on an MPLS SDP:

CLI syntax:
config>service>sdp#
    ldp
    signaling {off|tldp}

The following example displays an SDP configuration output with the signaling default tldp enabled.

ALU-1>config>service>sdp# info detail
----------------------------------------------
            description "MPLS: to-99"
            far-end 10.10.10.99
            ldp
            signaling tldp
            path-mtu 4462
            keep-alive
                hello-time 10
                hold-down-time 10
                max-drop-count 3
                timeout 5
                no message-length
                no shutdown
            exit
            no shutdown
----------------------------------------------
ALU-1>config>service>sdp#

LDP configuration management tasks

This section discusses the following LDP configuration management tasks:

Disabling LDP

The no ldp command disables the LDP protocol on the router. All parameters revert to the default settings. LDP must be shut down before it can be disabled.

Use the following CLI syntax to disable LDP:

CLI syntax:
no ldp
    shutdown
Example:
config>router# ldp
config>router>ldp# shutdown
config>router>ldp# exit
config>router# no ldp

Modifying targeted session parameters

You can modify targeted session parameters without shutting down entities. However, for any LDP timers (hello or keepalive timers), the changes do not take effect until a shutdown or no shutdown command is performed on the LDP session.

The no form of a targeted-session parameter command reverts modified values back to the default.

The following example displays the CLI syntax to revert targeted session parameters back to the default values.

Example:
config>router# ldp
config>router>ldp# targeted-session	
config>router>ldp>targeted# no disable-targeted-session
config>router>ldp>targeted# no hello
config>router>ldp>targeted# no keepalive 
config>router>ldp>targeted# shutdown
config>router>ldp>targeted# no shutdown
config>router>ldp>targeted# no peer 10.10.10.99

The following example displays the default value output.

ALU-1>config>router>ldp>targeted# info detail
----------------------------------------------
                no disable-targeted-session
                hello 45 3
                keepalive 40 4
----------------------------------------------
ALU-1>config>router>ldp>targeted#

Modifying interface parameters

You can modify LDP interface parameters without shutting down entities. However, at the global timer configuration level (ldp>interface-parameters), the hello and keepalive parameter modifications do not take effect until a shutdown or no shutdown command is performed on the LDP session. At the interface timer configuration level (ldp>interface-parameters>interface), any changes to the keepalive parameter do not take effect until a shutdown/no shutdown command is performed on the LDP session. For all other parameters, the changes take effect immediately.

Individual parameters cannot be deleted. The no form of an interface-parameter command changes modified values back to the defaults.

The following example displays the CLI syntax to change interface parameters back to the default values.

Example:
config>router# ldp
config>router>ldp>interface-parameters
config>router>ldp>if-params# no hello
config>router>ldp>if-params# interface to-104
config>router>ldp>if-params>if# no keepalive
config>router>ldp>if-params>if# no transport-address
config>router>ldp>if-params>if# shutdown
config>router>ldp>if-params>if# no shutdown
config>router>ldp>if-params>if# exit
config>router>ldp>if-params# exit
config>router>ldp# shutdown
config>router>ldp# no shutdown

The following example displays the default value output.

ALU-1>config>router>ldp>if-params# info detail
----------------------------------------------
                hello 15 3
                keepalive 30 3
                no transport-address
----------------------------------------------
ALU-1>config>router>ldp>params#

LDP command reference

Command hierarchies

LDP commands

config
    - router[router-name]
        - [no] ldp
            - [no] aggregate-prefix-match
                - prefix-exclude policy-name [policy-name...(up to 5 max)]
                - no prefix-exclude
                - [no] shutdown
            - egress-statistics
                - [no] fec-prefix ip-prefix[/mask]
                    - accounting-policy policy-id
                    - no accounting-policy
                    - [no] collect-stats
                    - [no] shutdown
            - export policy-name [policy-name...(up to 5 max)]
            - no export 
            - export-tunnel-table policy-name [policy-name...(up to 5 max)]
            - no export-tunnel-table
            - fast-reroute [backup-sr-tunnel]
            - no fast-reroute
            - fec-originate ip-address/mask [advertised-label in-label] [swap-label out-label] interface interface-name
            - fec-originate ip-address/mask [advertised-label in-label] next-hop ip-address [swap-label out-label]
            - fec-originate ip-address/mask [advertised-label in-label] next-hop ip-address [swap-label out-label] interface interface-name
            - fec-originate ip-address/mask [advertised-label in-label] pop
            - no fec-originate ip-address/mask interface interface-name
            - no fec-originate ip-address/mask next-hop ip-address
            - no fec-originate ip-address/mask next-hop ip-address interface interface-name
            - no fec-originate ip-address/mask pop
            - [no] graceful-restart 
                - maximum-recovery-time interval
                - no maximum-recovery-time
                - neighbor-liveness-time interval
                - no neighbor-liveness-time
            - [no] implicit-null-label 
            - import policy-name [policy-name...(up to 5 max)]
            - no import
            - interface-parameters
                -  interface ip-int-name [dual-stack]
                - [no] interface ip-int-name
                    - bfd-enable [ipv4] [ipv6]
                    - [no] bfd-enable
                    - [no] ipv4
                        - fec-type-capability
                            - p2mp-ipv4 {enable | disable}
                            - p2mp-ipv6 {enable | disable}
                            - prefix-ipv4 {enable | disable}
                            - prefix-ipv6 {enable | disable}
                        - hello timeout factor
                        - no hello
                        - keepalive timeout factor
                        - no keepalive
                        - local-lsr-id {system | interface}
                        - no local-lsr-id
                        - [no] shutdown
                        - transport-address {system | interface}
                        - no transport-address
                    - [no] ipv6
                        - fec-type-capability
                            - p2mp-ipv4 {enable | disable}
                            - p2mp-ipv6 {enable | disable}
                            - prefix-ipv4 {enable | disable}
                            - prefix-ipv6 {enable | disable}
                        - hello timeout factor
                        - no hello
                        - keepalive timeout factor
                        - no keepalive
                        - local-lsr-id {system | interface}
                        - no local-lsr-id
                        - [no] shutdown
                        - transport-address {system | interface}
                        - no transport-address
                - ipv4
                    - hello timeout factor
                    - no hello
                    - keepalive timeout factor
                    - no keepalive
                    - transport-address {system | interface}
                    - no transport-address
                - ipv6
                    - hello timeout factor
                    - no hello
                    - keepalive timeout factor
                    - no keepalive
                    - transport-address {system | interface}
                    - no transport-address
            - [no] legacy-ipv4-lsr-interop
            - [no] mcast-upstream-frr
            - mp-mbb-time interval 
            - no mp-mbb-time 
            - session-parameters
                - [no] peer ip-address
                    - export-addresses policy-name [policy-name... (up to 5 max)]
                    - no export-addresses 
                    - export-prefixes policy-name [policy-name... (up to 5 max)]
                    - no export-prefixes
                    - fec-type-capability 
                        - p2mp {enable | disable}
                        - prefix-ipv4 {enable | disable}
                        - prefix-ipv6 {enable | disable}
            - [no] shutdown
            - targeted-session
                - [no] disable-targeted-session
                -  ipv4
                    - hello timeout factor
                    - no hello
                    - keepalive timeout factor
                    - no keepalive
                -  ipv6
                    - hello timeout factor
                    - no hello
                    - keepalive timeout factor
                    - no keepalive
                - [no] peer ip-address
                    - [no] bfd-enable
                    - hello timeout factor
                    - no hello
                    - keepalive timeout factor 
                    - no keepalive
                    - local-lsr-id interface-name
                    - no local-lsr-id 
                    - [no] shutdown
                    - [no] tunneling 
                        - [no] lsp lsp-name 
            - tcp-session-parameters
                - [no] peer-transport ip-address
                    - auth-keychain name
                    - no auth-keychain 
                    - authentication-key {authentication-key | hash-key} [hash | hash2]
                    - no authentication-key 
                    - no authentication-key 
            - tunnel-down-damp-time seconds
            - no tunnel-down-damp-time

Show commands

The show commands in this section are organized into the following areas:

Show LDP commands
show
    - router [router-instance]
        - ldp
            - discovery [state state] [detail | summary] [adjacency-type type] [session ip-addr[label-space]]
            - discovery [state state] [detail | summary] [adjacency-type type] [family]
            - discovery interface [ip-int-name] [state state] [detail | summary] [session ip-addr[label-space]] [family]
            - discovery peer [ip-address] [state state] [detail | summary] [session ip-addr[label-space]]
            - fec-egress-stats [ip-prefix/mask]
            - fec-egress-stats [active] [family]
            - fec-originate [ip-address/mask] [operation-type]
            - fec-originate [operation-type] [family]
            - interface [ip-int-name | ip-address] [detail] [family] 
            - parameters
            - session [ip-addr[:label-space]] local-addresses [sent | recv] ip-addr ip-address
            - session [ip-addr[:label-space]] [session-type] [state state] [detail | summary]
            - session [ip-addr[:label-space]] local-addresses [sent | recv] [family]
            - session [ip-addr[:label-space]] statistics [packet-type] [session-type]
            - session statistics [packet-type] [session-type] [family]
            - session [session-type] [state state] [detail | summary] [family]
            - session-parameters [family]
            - session-parameters [peer-ip-address]
            - status
            - targ-peer [ip-address] [detail]
            - targ-peer [detail] [family] 
            - tcp-session-parameters [family] 
            - tcp-session-parameters [keychain keychain]
            - tcp-session-parameters transport-peer-ip-address
Show LDP bindings commands
show
    - router
        - ldp
            - bindings 
                - active detail [family] [egress-if port-id] 
                - active detail [family] [egress-lsp tunnel-id]
                - active detail [egress-nh ip-address] [family]
                - active egress-if port-id [summary | detail] [family]
                - active egress-lsp tunnel-id [summary | detail] [family]
                - active egress-nh [family] [summary | detail] ip-address
                - active ipv4 [summary | detail] [egress-if port-id]
                - active ipv4 [summary | detail] [egress-lsp tunnel-id]
                - active ipv4 [summary | detail] [egress-nh ip-address]
                - active ipv6 [summary | detail] [egress-if port-id]
                - active ipv6 [summary | detail] [egress-nh ip-address]
                - active ipv6 [summary | detail] [egress-lsp tunnel-id]
                - active p2mp p2mp-id identifier root ip-address [summary | detail] [egress-if port-id]
                - active p2mp p2mp-id identifier root ip-address [summary | detail] [egress-lsp tunnel-id] 
                - active p2mp p2mp-id identifier root ip-address [summary | detail] [egress-nh ip-address]  
                - active p2mp [family] [summary | detail] [egress-if port-id] [opaque-type opaque-type]
                - active p2mp [family] [summary | detail] [egress-lsp tunnel-id] [opaque-type opaque-type]
                - active p2mp [family] [summary | detail] [egress-nh ip-address] [opaque-type opaque-type]
                - active p2mp source ip-address group mcast-address root ip-address [summary | detail] [egress-if port-id] inner-root ip-address
                - active p2mp source ip-address group mcast-address root ip-address [summary | detail] [egress-lsp tunnel-id] inner-root ip-address
                - active p2mp source ip-address group mcast-address root ip-address [summary | detail] [egress-nh ip-address] inner-root ip-address
                - active p2mp source ip-address group mcast-address root ip-address [rd rd] [summary | detail] [egress-if port-id]
                - active p2mp source ip-address group mcast-address root ip-address [rd rd] [summary | detail] [egress-lsp tunnel-id]
                - active p2mp source ip-address group mcast-address root ip-address [rd rd] [summary | detail] [egress-nh ip-address]
                - active p2mp source ip-address group mcast-address [family] [summary | detail] [innermost-root ip-address]
                - active prefixes [family] [summary | detail] [egress-if port-id]
                - active prefixes [family] [summary | detail] [egress-lsp tunnel-id]
                - active prefixes [egress-nh ip-address] [family] [summary | detail]
                - active prefixes prefix ip-prefix/ip-prefix-length [summary | detail] [egress-if port-id]
                - active prefixes prefix ip-prefix/ip-prefix-length [summary | detail] [egress-lsp tunnel-id]
                - active prefixes prefix ip-prefix/ip-prefix-length [egress-nh ip-address] [summary | detail]
                - active summary [family] [egress-if port-id]
                - active summary [family] [egress-lsp tunnel-id]
                - active summary [egress-nh ip-address] [family]
show
    - router
        - ldp 
            - bindings 
                - detail [session ip-addr [label-space]] [family]
                - ipv4 [session ip-addr[label-space]] [summary | detail] 
                - ipv6 [session ip-addr[label-space]] [summary | detail] 
                - label-type start-label start-label [end-label end-label] label-type [family]
                - p2mp p2mp-id identifier root ip-address [session ip-addr [label-space]] [summary | detail]
                - p2mp [session ip-addr [label-space]] [family] [summary | detail] [opaque-type opaque-type]
                - p2mp source ip-address group mcast-address root ip-address [session ip-addr [label-space]] [family] [summary | detail] inner-root ip-address
                - p2mp source ip-address group mcast-address root ip-address [rd rd] [session ip-addr [label-space]] [summary | detail]
                - p2mp source ip-address group mcast-address [session ip-addr [label-space]] [family] [summary | detail] [innermost-root ip-address]
                - prefixes prefix ip-prefix/ip-prefix-length [summary | detail] [session ip-addr[label-space]]
                - prefixes [family] [summary | detail] [session ip-addr[label-space]]
                - services vc-type vc-type saii global-id:prefix:ac-id  [256 chars max]taii agi agi [detail] [service-id service-id] [session ip-addr[label-space]]
                - services vc-type vc-type agi agi [detail] [service-id service-id] [session ip-addr[label-space]]
                - services [vc-type vc-type] [svc-fec-type] [detail] [service-id service-id] [session ip-addr[label-space]]
                - services vc-type vc-type vc-id vc-id [detail] [service-id service-id] [session ip-addr[label-space]]
                - session [family] [summary | detail] ip-addr[label-space]
                - summary [session ip-addr[label-space]] [ipv4 | ipv6]

Monitor commands

monitor
    - router
        - ldp 
            - fec-egress-stats ip-prefix/mask [interval seconds] [repeat repeat] [absolute | rate]
            - session ldp-id[ldp-id...(up to 5 max)] [interval seconds] [repeat repeat] [absolute | rate] 
            - statistics [interval seconds] [repeat repeat] [absolute | rate]

Command descriptions

Configuration commands

Generic commands
shutdown
Syntax

[no] shutdown

Context

config>router>ldp

config>router>ldp>egress-statistics

config>router>ldp>if-params>interface

config>router>ldp>if-params>if>ipv4

config>router>ldp>if-params>if>ipv6

config>router>ldp>targ-session>peer

config>router>ldp>aggregate-prefix-match

Description

This command administratively disables an entity. When disabled, an entity does not change, reset, or remove any configuration settings or statistics.

The operational state of the entity is disabled as well as the operational state of any entities contained within. Many objects must be shut down before they can be deleted.

The no form of this command administratively enables an entity.

Unlike other commands and parameters where the default state is not indicated in the configuration file, the shutdown and no shutdown states are always indicated in system-generated configuration files.

Default

no shutdown

LDP global commands
ldp
Syntax

[no] ldp

Context

config>router

Description

This command enables the context to configure an LDP protocol instance.

When an LDP instance is created, the protocol is enabled (in the no shutdown state). To suspend the LDP protocol, use the shutdown command. Configuration parameters are not affected.

The no form of the command deletes the LDP protocol instance, removing all associated configuration parameters. The LDP instance must first be disabled with the shutdown command before being deleted.

Default

n/a — LDP must be explicitly enabled

aggregate-prefix-match
Syntax

[no] aggregate-prefix-match

Context

config>router>ldp

Description

This command enables LDP to use the aggregate prefix match function instead of requiring an exact prefix match.

When this command is enabled and an LSR receives a FEC-label binding from an LDP neighbor for a prefix-address FEC element, FEC1, it installs the binding in the LDP FIB if:

  • the routing table (RIB) contains an entry that matches FEC1. Matching can either be a longest IP match of the FEC prefix or an exact match.

  • the advertising LDP neighbor is the next hop to reach FEC1

When the FEC-label binding has been installed in the LDP FIB, LDP programs an NHLFE entry in the egress data path to forward packets to FEC1. LDP also advertises a new FEC-label binding for FEC1 to all its LDP neighbors.

When a new prefix appears in the RIB, LDP checks the LDP FIB to determine if this prefix is a closer match for any of the installed FEC elements. If a closer match is found, this may mean that the LSR used as the next hop changes; if so, the NHLFE entry for that FEC must be changed.

When a prefix is removed from the RIB, LDP checks the LDP FIB for all FEC elements that matched this prefix to determine if another match exists in the routing table. If another match exists, LDP must use it. This may mean that the LSR used as the next hop also changes; if so, the NHLFE entry for that FEC must be changed. If another match does not exist, the LSR removes the FEC binding and sends a label withdraw message to its LDP neighbors.

If the next hop for a routing prefix changes, LDP updates the LDP FIB entry for the FEC elements that matched this prefix. It also updates the NHLFE entry for the FEC elements.

The no form of this command disables the use of the aggregate prefix match function. LDP then only performs an exact prefix match for FEC elements.

Default

no aggregate-prefix-match

prefix-exclude
Syntax

prefix-exclude policy-name[policy-name …(up to 5 max)]

no prefix-exclude

Context

config>router>ldp>aggregate-prefix-match

Description

This command specifies the policy name containing the prefixes to be excluded from the aggregate prefix match function. Against each excluded prefix, LDP performs an exact match of a specific FEC element prefix, instead of a longest prefix match of one or more LDP FEC element prefixes, when it receives a FEC-label binding or when a change to the prefix occurs in the routing table.

The no form of this command removes all policies from the configuration; therefore, no prefixes are excluded.

Default

no prefix-exclude

Parameters
policy-name

specifies the import route policy name. Allowed values are any string up to 32 characters long composed of printable, 7-bit ASCII characters. If the string contains special characters (such as #, $, spaces), the entire string must be enclosed within double quotes.

egress-statistics
Syntax

egress-statistics

Context

config>router>ldp

Description

This command enters the context to enable egress data path statistics at the ingress LER for this FEC.

Default

n/a

fec-prefix
Syntax

[no] fec-prefix ip-prefix[/mask]

Context

config>router>ldp>egress-statistics

Description

This command configures statistics in the egress data path at the ingress LER or LSR for an LDP FEC. The user must also execute the no shutdown command in this context to enable statistics collection.

The no form of this command disables the statistics in the egress data path and removes the accounting policy association from the LDP FEC.

Default

n/a

Parameters
ip-prefix[/mask]

the IP prefix and prefix length associated with the prefix FEC

Values

ipv4-prefix:

a.b.c.d

ipv4-prefix-length:

32

ipv6-prefix:

x:x:x:x:x:x:x:x (eight 16-bit pieces)

x:x:x:x:x:x:d.d.d.d

x - [0 to FFFF]H

d - [0 to 255]D

ipv6-prefix-length:

128

accounting-policy
Syntax

accounting-policy policy-id

no accounting-policy

Context

config>router>ldp>egr-stats>fec-prefix

Description

This command associates an accounting policy with an LDP FEC. Only one accounting policy at a time can be associated with an LDP FEC on a particular node.

An accounting policy must first be configured in the config>log>accounting-policy context before it can be associated; otherwise an error message is generated.

The no form of this command removes the accounting policy association.

Default

no accounting policy

Parameters
policy-id

the accounting policy ID

Values

1 to 99

collect-stats
Syntax

[no] collect-stats

Context

config>router>ldp>egr-stats>fec-prefix

Description

This command enables accounting and statistical data collection.

The collected statistic counters can be retrieved via show and monitor commands or with the SNMPv3 interface. The counters can be saved to an accounting file if the specific statistics collection record is included in the default accounting policy or in a user-defined accounting policy.

When the no form of this command is issued, statistics are still accumulated by the forwarding engine; however, the CPU does not obtain the results and write them to the accounting file. If a subsequent collect-stats command is issued, then the counters written to the accounting file also includes all the traffic that went through while the no collect-stats command was in effect.

Default

no collect-stats

export
Syntax

export policy-name[policy-name …(up to 5 max)]

no export

Context

config>router>ldp

Description

This command specifies export route policies that determine which routes are exported to LDP neighbors. Configuring an export policy allows the LSR (Label Switch Router) to advertise addresses other than the system IP address. Policies are configured in the config>router>policy-options context. See the ‟Route Policies” section in the 7705 SAR Router Configuration Guide.

If no export policy is specified, non-LDP routes are not be exported from the routing table manager to LDP, and only LDP-learned routes are exported to LDP neighbors.

If multiple policy names are specified, the policies are evaluated in the order they are specified. The first policy that matches is applied. If multiple export commands are issued, the last command entered overrides the previous command. A maximum of five policy names can be specified. The specified names must already be defined.

The no form of the command removes all policies from the configuration.

Default

no export

Parameters
policy-name

specifies the export route policy name. Allowed values are any string up to 32 characters long composed of printable, 7-bit ASCII characters. If the string contains special characters (such as #, $, spaces), the entire string must be enclosed within double quotes.

export-tunnel-table
Syntax

export-tunnel-table policy-name [policy-name...(up to 5 max)]

no export-tunnel-table

Context

config>router>ldp

Description

This command enables exporting of SR tunnels from the TTM into LDP (IGP) for the purpose of stitching an LDP FEC to an SR tunnel for the same destination IPv4 /32 IS-IS prefix.

The no form of the command disables the exporting of SR tunnels to LDP.

Default

no export-tunnel-table

Parameters
policy-name

the export-tunnel-table route policy name; must be an existing policy-statement name

fast-reroute
Syntax

fast-reroute [backup-sr-tunnel]

no fast-reroute

Context

config>router>ldp

Description

This command enables LDP Fast Reroute (FRR). LDP FRR provides local protection for an LDP FEC by precalculating and downloading a primary and a backup NHLFE for the FEC to the LDP FIB.

This command is limited to IPv4 /32 prefixes in both LDP and SR.

When LDP FRR is enabled and an LFA backup next hop exists for the FEC prefix in the RTM, or for the longest prefix the FEC prefix matches to when the aggregate-prefix-match command is enabled, LDP programs the data path with both a primary NHLFE and a backup NHLFE for each next hop of the FEC.

The backup NHLFE is enabled for each affected FEC next hop when any of the following events occurs:

  • an LDP interface goes operationally down or is administratively shut down

  • an LDP session to a peer goes down because the Hello timer or keepalive timer has expired over an interface

  • the TCP connection used by a link LDP session to a peer goes down

The tunnel-down-damp-time command, when enabled, does not cause the corresponding timer to be activated for a FEC as long as a backup NHLFE is still available.

Because LDP can detect the loss of a neighbor/next hop independently, it is possible that it can switch to the LFA next hop while the IGP (OSPF or IS-IS) is still using the primary next hop. As well, when the interface for the previous primary next hop is restored, the IGP may reconverge before LDP completes the FEC exchange with its neighbor over that interface. This may cause LDP to deprogram the LFA next hop from the FEC and blackhole traffic. To avoid this situation, IGP-LDP synchronization should be enabled on the LDP interface with the config>router>if>ldp-sync-timer command (see the 7705 SAR Router Configuration Guide, ‟IP Router Command Reference”, for information about configuring the ldp-sync-timer).

The backup-sr-tunnel option allows an SR tunnel to be used as a remote LFA or TI-LFA backup tunnel next hop by an LDP FEC. Before this option can be used, the LDP-to-SR stitching feature must be enabled. See LDP-to-segment routing stitching for IPv4 /32 prefixes (IS-IS) for more information about this feature.

The no form of this command disables LDP FRR.

Default

no fast-reroute

Parameters
backup-sr-tunnel

allows an SR tunnel to be used as a remote LFA or TI-LFA backup tunnel next hop by an LDP FEC

fec-originate
Syntax

fec-originate ip-address/mask [advertised-label in-label] [swap-label out-label] interface interface-name

fec-originate ip-address/mask [advertised-label in-label] next-hop ip-address [swap-label out-label]

fec-originate ip-address/mask [advertised-label in-label] next-hop ip-address [swap-label out-label] interface interface-name

fec-originate ip-address/mask [advertised-label in-label] pop

no fec-originate ip-address/mask interface interface-name

no fec-originate ip-address/mask next-hop ip-address

no fec-originate ip-address/mask next-hop ip-address interface interface-name

no fec-originate ip-address/mask pop

Context

config>router>ldp

Description

This command adds a FEC to the LDP prefix database with a specific label operation on the node.

Permitted operations are swap to originate a FEC for which the LSR is not egress or pop to originate a FEC for which the LSR is egress.

For a swap operation, an incoming label can be swapped with a label in the range of 16 to 1048575. If a swap-label is not configured, the default value is 3.

A route-table entry is required for a FEC with a pop operation to be advertised. For a FEC with a swap operation, a route-table entry must exist and the user-configured next hop for the swap operation must match one of the next hops in the route-table entry.

The next-hop, advertised-label, and swap-label parameters are optional. If a next-hop is configured but no swap-label is specified, the swap occurs with label 3 (implicit null), then the label is popped and the packet is forwarded to the next hop. If the next-hop and swap-label parameters are configured, a regular swap occurs. If no parameters are specified, a pop and forwarding is performed.

Default

no fec-originate

Parameters
ip-address/mask

specifies the IP prefix and mask length

Values

ipv4-address

a.b.c.d (host bits must be 0)

ipv6-address

x:x:x:x:x:x:x:x (eight 16-bit pieces)

x:x:x:x:x:x:d.d.d.d

x: [0 to FFFF]H

d: [0 to 255]D

ipv6-prefix-length - [0 to 128]

mask

0 to 32

advertised label

specifies the label advertised to the upstream peer. If not configured, the label that is advertised should be from the label pool. If the configured static label is not available, the IP prefix is not advertised.

in-label

the LSR to swap the label. If configured, the LSR should swap the label with the configured out-label. If not configured, the default action is pop if the next-hop parameter is not defined.

Values

32 to 2047

out-label

the number of labels to send to the peer associated with this FEC

Values

16 to 1048575

interface-name

specifies the name of the interface that the label for the originated FEC is swapped to. For an unnumbered interface, this parameter is mandatory because there is no address for the next hop. For a numbered interface, it is optional.

next-hop ip-address

specifies the IP address of the next hop

Values

a.b.c.d

pop

specifies to pop the label and transmit the packet

graceful-restart
Syntax

[no] graceful-restart

Context

config>router>ldp

Description

This command enables graceful restart helper.

The no form of the command disables graceful restart.

Default

graceful-restart

maximum-recovery-time
Syntax

maximum-recovery-time interval

no maximum-recovery-time

Context

config>router>ldp>graceful-restart

Description

This command configures the local maximum recovery time, which is the time (in seconds) that the sender of the TLV would like the receiver to wait, after detecting the failure of LDP communication with the sender.

The no form of the command returns the default value.

Default

120

Parameters
interval

specifies the maximum length of recovery time, in seconds

Values

15 to 1800

neighbor-liveness-time
Syntax

neighbor-liveness-time interval

no neighbor-liveness-time

Context

config>router>ldp>graceful-restart

Description

This command configures the neighbor liveness time, which is the time (in seconds) that the LSR retains its MPLS forwarding state. The time should be long enough to allow the neighboring LSRs to resynchronize all the LSPs in a graceful manner, without creating congestion in the LDP control plane.

The no form of the command returns the default value.

Default

120

Parameters
interval

specifies the length of time, in seconds

Values

5 to 300

implicit-null-label
Syntax

[no] implicit-null-label

Context

config>router>ldp

Description

This command enables the implicit null label option for all LDP FECs for which the router is the eLER.

The implicit null label is signaled by the eLER to the previous-hop LSR during FEC signaling by the LDP control protocol. When the implicit null label is signaled to the LSR, it pops the outer label before sending the MPLS packet to the eLER; this is known as penultimate hop popping.

The no form of the command disables the signaling of the implicit null label.

Default

no implicit-null-label

import
Syntax

import policy-name[policy-name …(up to 5 max)]

no import

Context

config>router>ldp

Description

This command specifies import route policies that determine which routes are accepted from LDP neighbors. Policies are configured in the config>router>policy-options context. See the ‟Route Policies” section in the 7705 SAR Router Configuration Guide.

If no import policy is specified, LDP accepts all routes from configured LDP neighbors. Import policies can be used to limit or modify the routes accepted and their corresponding parameters and metrics.

If multiple policy names are specified, the policies are evaluated in the order they are specified. The first policy that matches is applied. If multiple import commands are issued, the last command entered overrides the previous command. A maximum of five policy names can be specified. The specified names must already be defined.

The no form of the command removes all policies from the configuration.

Default

no import

Parameters
policy-name

specifies the import route policy name. Allowed values are any string up to 32 characters long composed of printable, 7-bit ASCII characters. If the string contains special characters (such as #, $, spaces), the entire string must be enclosed within double quotes.

hello
Syntax

hello timeoutfactor

no hello

Context

config>router>ldp>if-params>ipv4

config>router>ldp>if-params>ipv6

config>router>ldp>if-params>if>ipv4

config>router>ldp>if-params>if>ipv6

config>router>ldp>targ-session>ipv4

config>router>ldp>targ-session>ipv6

config>router>ldp>targ-session>peer

Description

This command configures the hold time. This is the time interval to wait before declaring a neighbor down. The factor parameter derives the hello interval.

Hold time is local to the system and is sent in the hello messages to the neighbor. Hold time cannot be less than three times the hello interval. The hold time can be configured globally (applies to all LDP interfaces) or per interface. The most specific value is used.

After an LDP session is being set up, the hold time is negotiated to the lower of the two peers. After an operational value is agreed upon, the hello factor is used to derive the value of the hello interval.

The no form of the command:

  • at the interface-parameters and targeted-session levels, sets the hello timeout and the hello factor to the default values

  • at the interface level, sets the hello timeout and the hello factor to the value defined under the interface-parameters level

  • at the peer level, sets the hello timeout and the hello factor to the value defined under the targeted-session level

Default

The default value is dependent upon the CLI context. Hello Timeout Factor default values lists the hello timeout factor default values.

Table 3. Hello Timeout Factor default values

Context

Timeout

Factor

config>router>ldp>if-params>ipv4

config>router>ldp>if-params>ipv6

15

3

config>router>ldp>if-params>interface>ipv4

config>router>ldp>if-params>interface>ipv6

Inherits values from interface-parameters context

config>router>ldp>targ-session>ipv4

config>router>ldp>targ-session>ipv6

45

3

config>router>ldp>targ-session>peer

Inherits values from targeted-session IPv4 or IPv6 context

Parameters
timeout

configures the time interval, in seconds, that LDP waits before declaring a neighbor down

Values

1 to 65535

factor

specifies the number of keepalive messages that should be sent on an idle LDP session in the hello timeout interval

Values

1 to 255

keepalive
Syntax

keepalive timeoutfactor

no keepalive

Context

config>router>ldp>if-params>ipv4

config>router>ldp>if-params>ipv6

config>router>ldp>if-params>if>ipv4

config>router>ldp>if-params>if>ipv6

config>router>ldp>targ-session>ipv4

config>router>ldp>targ-session>ipv6

config>router>ldp>targ-session>peer

Description

This command configures the time interval, in seconds, that LDP waits before tearing down the session. The factor parameter derives the keepalive interval.

If no LDP messages are exchanged for the configured time interval, the LDP session is torn down. Keepalive timeout is usually three times the keepalive interval. To maintain the session permanently, regardless of the activity, set the value to zero.

After an LDP session is set up, the keepalive timeout is negotiated to the lower of the two peers. After an operational value is agreed upon, the keepalive factor is used to derive the value of the keepalive interval.

The no form of the command:

  • at the IPv4, IPv6, and targeted-session levels, sets the keepalive timeout and the keepalive factor to the default value

  • at the IPv4 or IPv6 interface level, sets the keepalive timeout and the keepalive factor to the value defined under the corresponding interface-parameters level

  • at the peer level, sets the keepalive timeout and the keepalive factor to the value defined under the targeted-session level

Default

The default value is dependent upon the CLI context. Keepalive Timeout Factor default values lists the keepalive timeout factor default values.

Table 4. Keepalive Timeout Factor default values

Context

Timeout

Factor

config>router>ldp>if-params>ipv4

config>router>ldp>if-params>ipv6

30

3

config>router>ldp>if-params>interface>ipv4

config>router>ldp>if-params>interface>ipv6

Inherits values from interface-parameters context

config>router>ldp>targ-session>ipv4

config>router>ldp>targ-session>ipv6

40

4

config>router>ldp>targ-session>peer

Inherits values from targeted-session IPv4 or IPv6 context

Parameters
timeout

configures the time interval, expressed in seconds, that LDP waits before tearing down the session

Values

1 to 65535

factor

specifies the number of keepalive messages, expressed as a decimal integer, that should be sent on an idle LDP session in the keepalive timeout interval

Values

1 to 255

legacy-ipv4-lsr-interop
Syntax

[no] legacy-ipv4-lsr-interop

Context

config>router>ldp

Description

This command allows interoperability with third-party legacy IPv4 LSR implementations that do not comply with RFC 5036 with respect to the processing of Hello TLVs with the U-bit set.

The command is a global LDP configuration that disables the Nokia proprietary Interface Info TLV (0x3E05) in the Hello message sent to the peer. Disabling this Hello TLV also results in the non-generation of the Nokia proprietary Hello Adjacency Status TLV (0x3E06) because the Interface Info TLV is not sent.

In addition, this command disables the RFC 7552 standard dual-stack capability TLV (0x701) and the Nokia proprietary Adjacency capability TLV (0x3E07).

mcast-upstream-frr
Syntax

[no] mcast-upstream-frr

Context

config>router>ldp

Description

This command enables the mLDP fast upstream switchover feature.

When this command is enabled and LDP is resolving an mLDP FEC received from a downstream LSR, it checks whether an ECMP next hop or an LFA next hop to the root LSR node exists. If LDP finds one, it programs a primary ILM on the interface corresponding to the primary next hop and a backup ILM on the interface corresponding to the ECMP or LFA next hop. Then, LDP sends the corresponding labels to both upstream LSR nodes. Under normal operation, the primary ILM accepts packets while the backup ILM drops them. If the interface or the upstream LSR of the primary ILM goes down, causing the LDP session to go down, the backup ILM starts accepting packets.

To make use of the ECMP next hop, the user must configure the ecmp value in the system to at least ‟2”, using the following command:

config>router>ecmp

To make use of the LFA next hop, the user must enable LFA using the following commands (as needed):

config>router>isis>loopfree-alternates

config>router>ospf>loopfree-alternates

Enabling the IP FRR or LDP FRR feature is not strictly required because LDP only needs to know the location of the alternate next hop to the root LSR so it can send the Label Mapping message to program the backup ILM at the initial signaling of the tree. Therefore, enabling the LFA option is sufficient. However, if unicast IP and LDP prefixes need to be protected, then these features and the mLDP fast upstream switchover can be enabled concurrently.

The mLDP FRR fast switchover relies on the fast detection of a loss of an LDP session to the upstream peer to which the primary ILM label had been advertised. It is strongly recommended that the following be performed:

  1. Enable BFD on all LDP interfaces to upstream LSR nodes. When BFD detects the loss of the last adjacency to the upstream LSR, it immediately brings down the LDP session, which causes the CSM to activate the backup ILM.

  2. If there is a concurrent T-LDP adjacency to the same upstream LSR node, enable BFD on the T-LDP peer in addition to enabling it on the interface.

  3. Enable the ldp-sync-timer option on all interfaces to the upstream LSR nodes. If an LDP session to the upstream LSR to which the primary ILM is resolved goes down for any reason other than a failure of the interface or of the upstream LSR, routing and LDP goes out of synchronization. This means that the backup ILM remains activated until the next time SPF is run by IGP. By enabling the IGP-LDP synchronization feature, the advertised link metric is changed to the maximum value as soon as the LDP session goes down. This, in turn, triggers an SPF, and LDP downloads a new set of primary and backup ILMs.

The no form of this command disables fast upstream switchover for mLDP FECs.

Default

no mcast-upstream-frr

mp-mbb-time
Syntax

mp-mbb-time interval

no mp-mbb-time

Context

config>router>ldp

Description

This command configures the maximum time a point-to-multipoint transit or bud node must wait before switching over to the new path if the new node does not send an MBB TLV to inform the transit or bud node of the availability of the data plane.

The no form of the command sets the wait time to the default.

Default

3 s

Parameters
interval

specifies the MP MBB wait time

Values

1 to 10 seconds

tunnel-down-damp-time
Syntax

tunnel-down-damp-time seconds

no tunnel-down-damp-time

Context

config>router>ldp

Description

This command specifies the time interval, in seconds, that LDP waits before posting a tunnel down event to the Tunnel Table Manager (TTM).

When LDP can no longer resolve a FEC and deactivates it, it deprograms the NHLFE in the data path; however, it delays deleting the LDP tunnel entry in the TTM until the tunnel-down-damp-time timer expires. This means that users of the LDP tunnel, such as SDPs (for all services) and BGP (for Layer 3 VPNs), is not be notified immediately. Traffic is still blackholed because the NHLFE has been deprogrammed.

If the FEC gets resolved before the tunnel-down-damp-time timer expires, LDP programs the IOM with the new NHLFE and posts a tunnel modify event to the TTM, updating the dampened entry in the TTM with the new NHLFE information.

If the FEC does not get resolved and the tunnel-down-damp-time timer expires, LDP posts a tunnel down event to the TTM, which deletes the LDP tunnel.

The no form of the command resets the damp timer value back to the default value of 3. If the timer value is set to 0, tunnel down events are not dampened but are reported immediately.

Default

3

Parameters
seconds

the time interval that LDP waits before posting a tunnel down event to the TTM

Values

0 to 20

Interface parameters commands
interface-parameters
Syntax

interface-parameters

Context

config>router>ldp

Description

This command enables the context to configure LDP interfaces and parameters that apply to LDP interfaces.

interface
Syntax

interface ip-int-namedual-stack]

[no] interface ip-int-name

Context

config>router>ldp>if-params

Description

This command enables LDP on the specified IP interface.

The no form of the command deletes the LDP interface and all configuration information associated with the LDP interface.

The LDP interface must be disabled using the shutdown command before it can be deleted.

You can configure different parameters for IPv4 and IPv6 LDP interfaces by entering ipv4 or ipv6 as the next command.

Parameters
dual-stack

distinguishes between configurations created before 7705 SAR Release 9.0 from those created in Release 9.0 or later when the interface node implementation was changed to include both IPv4 and IPv6 contexts. If the dual-stack keyword is used, then the IPv4 interface context is not created. If the keyword is not used, then the IPv4 interface context is automatically created.

When entering an already configured interface, there is no need to provide the keyword; it is ignored if it is included.

By default, all configurations created in Release 9.0 or later include dual-stack.

ip-int-name

specifies an existing interface. If the string contains special characters (such as #, $, spaces), the entire string must be enclosed within double quotes.

ipv4
Syntax

[no] ipv4

Context

config>router>ldp>if-params

config>router>ldp>if-params>if

config>router>ldp>targeted-session

Description

This command enables the context to configure IPv4 LDP parameters that apply to the interface.

ipv6
Syntax

[no] ipv6

Context

config>router>ldp>if-params

config>router>ldp>if-params>if

config>router>ldp>targeted-session

Description

This command enables the context to configure IPv6 LDP parameters applied to the interface.

local-lsr-id
Syntax

local-lsr-id {system | interface}

no local-lsr-id

Context

config>router>ldp>if-params>if>ipv4

config>router>ldp>if-params>if>ipv6

Description

This command enables the use of the address of the link LDP interface as the LSR ID to establish an LDP adjacency and session with a directly connected LDP peer.

By default, the LDP session uses the system interface address as the LSR ID unless the LSR ID is explicitly configured. This means that targeted LDP (T-LDP) and interface LDP share a common LDP TCP session and therefore a common LDP label space. The system interface must always be configured on the router or the LDP protocol does not come up on the node.

At initial configuration, the LDP session to the peer remains down while the interface is down. If the user changes the LSR ID while the LDP session is up, LDP immediately tears down the session and attempts to re-establish it using the new LSR ID. If the interface used for the local LSR ID goes down, the LDP session also goes down.

The interface option is the recommended setting when static route-LDP synchronization is enabled.

When the interface option is selected, the transport connection (TCP) for the link LDP session configured by the transport-address command is automatically set to interface. Having both the local-lsr-id and transport address set to the local interface creates two TCP sessions to the peer and therefore two different LDP label spaces: one to the interface IP address for link LDP (L-LDP) and one to the system IP address for T-LDP.

The no form of the command resets the local-lsr-id to the default value.

Default

system

Parameters
system

specifies that the system IP address is used to set up the LDP session between peers

interface

specifies that the IP interface address is used to set up the LDP session between peers

p2mp-ipv4
Syntax

p2mp-ipv4 {enable | disable}

Context

config>router>ldp>session-params>if>ipv4>fec-type-capability

config>router>ldp>session-params>if>ipv6>fec-type-capability

Description

This command enables or disables IPv4 P2MP FEC capability on the interface.

Default

p2mp disable

Parameters
enable | disable

enables or disables IPv4 P2MP FEC capability

p2mp-ipv6
Syntax

p2mp-ipv6 {enable | disable}

Context

config>router>ldp>session-params>if>ipv4>fec-type-capability

config>router>ldp>session-params>if>ipv6>fec-type-capability

Description

This command enables or disables IPv6 P2MP FEC capability on the interface.

Default

p2mp disable

Parameters
enable | disable

enables or disables IPv6 P2MP FEC capability

transport-address
Syntax

transport-address {system | interface}

no transport-address

Context

config>router>ldp>if-params>ipv4

config>router>ldp>if-params>ipv6

config>router>ldp>if-params>if>ipv4

config>router>ldp>if-params>if>ipv6

Description

This command configures the transport address to be used when setting up the LDP TCP sessions. The transport address can be configured globally (applies to all LDP interfaces) or per interface. The most specific value is used.

With the transport-address command, you can set up the LDP interface to the connection that can be set to the interface address or the system address. However, there can be an issue of which address to use when there are parallel adjacencies. This address selection situation can also occur when there is a link and a targeted adjacency, because targeted adjacencies request the session to be set up only to the system IP address.

The transport-address value should not be interface if multiple interfaces exist between two LDP neighbors.

Depending on the first adjacency to be formed, the TCP endpoint is chosen. In other words, if one LDP interface is set up as transport-address interface and another as transport-address system, then, depending on which adjacency was set up first, the TCP endpoint addresses are determined. After that, because the hello contains the LSR ID, the LDP session can be checked to verify that it is set up and then the adjacency can be matched to the session.

The no form of the command:

  • at the global level, sets the transport address to the default value

  • at the interface level, sets the transport address to the value defined under the global level

Default

system

Parameters
interface

specifies that the IP interface address is used to set up the LDP session between neighbors. The transport address interface cannot be used if multiple interfaces exist between two neighbors, because only one LDP session is set up between two neighbors.

system

specifies that the system IP address is used to set up the LDP session between neighbors

Session parameters commands
session-parameters
Syntax

session-parameters

Context

config>router>ldp

Description

This command enables the context to configure peer-specific parameters.

peer
Syntax

[no] peer ip-address

Context

config>router>ldp>session-params

Description

This command configures parameters for an LDP peer.

Default

n/a

Parameters
ip-address

specifies the LDP peer in dotted-decimal notation

export-addresses
Syntax

export-addresses policy-name [policy-name...(up to 5 max)]

no export-addresses

Context

config>router>ldp>session-params>peer

Description

This command specifies the export prefix policy to local addresses advertised to this peer.

Policies are configured in the config>router>policy-options context. A maximum of five policy names can be specified.

The no form of the command removes the policy from the configuration.

Default

no export-addresses

Parameters
policy-name

the name of an existing export prefix route policy

export-prefixes
Syntax

export-prefixes policy-name [policy-name...(up to 5 max)]

no export-prefixes

Context

config>router>ldp>session-params>peer

Description

This command specifies the export route policy used to determine which prefixes received from other LDP peers are redistributed to this LDP via the LDP session to this peer. Any prefix that has been accepted in the route policy will be exported. Any prefix that has been filtered out of the route policy will not be exported.

Policies are configured in the config>router>policy-options context. A maximum of five policy names can be specified. The peer address must be the peer LSR ID.

If no export policy is specified, all FEC prefixes learned will be exported to this LDP peer. This policy is applied in addition to the global LDP export policy and targeted sessions.

The no form of the command removes the policy from the configuration.

Default

no export-prefixes

Parameters
policy-name

the name of an existing export policy

fec-type-capability
Syntax

fec-type-capability

Context

config>router>ldp>if-params>if>ipv4

config>router>ldp>if-params>if>ipv6

config>router>ldp>session-params>peer

Description

This command enables or disables the advertisement of a FEC type for a specified LDP session or Hello adjacency to a peer.

Default

n/a

p2mp
Syntax

p2mp {enable | disable}

Context

config>router>ldp>session-params>peer>fec-type-capability

Description

This command enables or disables P2MP FEC capability for the session.

Default

p2mp disable

Parameters
enable | disable

enables or disables P2MP FEC capability

prefix-ipv4
Syntax

prefix-ipv4 {enable | disable}

Context

config>router>ldp>if-params>if>ipv4>fec-type-capability

config>router>ldp>if-params>if>ipv6>fec-type-capability

config>router>ldp>session-params>peer>fec-type-capability

Description

This command enables or disables IPv4 prefix FEC capability on the session or interface.

Default

prefix-ipv4 disable

Parameters
enable | disable

enables or disables IPv4 prefix FEC capability

prefix-ipv6
Syntax

prefix-ipv6 {enable | disable}

Context

config>router>ldp>if-params>if>ipv4

config>router>ldp>if-params>if>ipv6

config>router>ldp>session-params>peer>fec-type-capability

Description

This command enables or disables IPv6 prefix FEC capability on the session or interface.

Default

prefix-ipv6 disable

Parameters
enable | disable

enables or disables IPv6 prefix FEC capability

tcp-session-parameters
Syntax

tcp-session-parameters

Context

config>router>ldp

Description

This command enables the context to configure parameters for the TCP transport session of an LDP session to a remote peer.

Default

n/a

peer-transport
Syntax

[no] peer-transport ip-address

Context

config>router>ldp>tcp-session-parameters

Description

This command configures the peer transport address, which is the IPv4 or IPv6 destination address of the TCP connection to the LDP peer.

Default

n/a

Parameters
ip-address

the IPv4 or IPv6 address of the TCP connection to the LDP peer in dotted-decimal notation

auth-keychain
Syntax

auth-keychain name

no auth-keychain

Context

config>router>ldp>tcp-session-params>peer-transport

Description

This command associates an authentication keychain with LDP. The keychain is a collection of keys used to authenticate LDP messages from remote peers. The keychain allows the rollover of authentication keys during the lifetime of a session and also supports stronger authentication algorithms than clear text and MD5.

The keychain must already be defined in the config>system>security>keychain context.

Either the authentication-key command or the auth-keychain command can be used by LDP, but both cannot be supported at the same time. If both commands are configured, the auth-keychain configuration is applied and the authentication-key command is ignored.

By default, authentication is not enabled.

Default

no auth-keychain

Parameters
name

the name of an existing keychain, up to 32 characters

authentication-key
Syntax

authentication-key {authentication-key|hash-key}[hash | hash2]

no authentication-key

Context

config>router>ldp>tcp-session-params>peer-transport

Description

This command specifies the authentication key to be used between LDP peers before establishing sessions. Authentication uses the MD5 message-based digest.

Either the authentication-key command or the auth-keychain command can be used by LDP, but both cannot be supported at the same time. If both commands are configured, the auth-keychain configuration is applied and the authentication-key command is ignored.

The no form of this command disables authentication.

Default

n/a

Parameters
authentication-key

specifies the authentication key. Allowed values are any string up to 16 characters long (unencrypted) composed of printable, 7-bit ASCII characters. If the string contains special characters (such as #, $, spaces), the entire string must be enclosed within double quotes.

hash-key

specifies the hash key. Allowed values are any string up to 33 characters long composed of printable, 7-bit ASCII characters. If the string contains special characters (such as #, $, spaces), the entire string must be enclosed within double quotes.

This is useful when a user must configure the parameter; however, for security purposes, the actual unencrypted key value is not provided.

hash

specifies that the key is entered and stored on the node in encrypted form

hash2

specifies that the key is entered and stored on the node in a more complex encrypted form

Note: If neither the hash nor hash2 keyword is specified, the key is entered in clear text. However, for security purposes, the key is stored on the node using hash encryption.
Targeted session commands
targeted-session
Syntax

targeted-session

Context

config>router>ldp

Description

This command configures targeted LDP sessions. Targeted sessions are LDP sessions between non-directly connected peers. Hello messages are sent directly to the peer platform instead of to all the routers on this subnet multicast address.

The discovery messages for an indirect LDP session are addressed to the specified peer and not to the multicast address.

Default

n/a

disable-targeted-session
Syntax

[no] disable-targeted-session

Context

config>router>ldp>targeted-session

Description

This command disables support for targeted sessions. Targeted sessions are LDP sessions between non-directly connected peers. The discovery messages for an indirect LDP session are addressed to the specified peer and not to the multicast address.

The no form of the command enables the setup of any targeted sessions.

Default

no disable-targeted-session

peer
Syntax

[no] peer ip-address

Context

config>router>ldp>targeted-session

Description

This command configures parameters for an LDP peer.

Default

n/a

Parameters
ip-address

specifies the IPv4 or IPv6 address of the LDP peer in dotted-decimal notation

bfd-enable
Syntax

bfd-enable [ipv4][ipv6]

[no] bfd-enable

Context

config>router>ldp>if-params>if

config>router>ldp>targeted-session>peer

Description

This command enables or disables bidirectional forwarding detection (BFD) tracking of the LDP session for the interface or the T-LDP session for the peer.

When BFD is enabled on an LDP interface, the system tracks the next hop of the IPv4 and IPv6 prefixes in addition to tracking the LDP peer address of the Hello adjacency over that link. This is required because LDP can resolve both IPv4 and IPv6 prefix FECs over a single IPv4 or IPv6 LDP session and therefore, the next hop of a prefix does not necessarily match the LDP peer source address of the Hello adjacency.

The no form of the command disables BFD tracking.

Default

n/a

local-lsr-id
Syntax

local-lsr-id interface-name

no local-lsr-id

Context

config>router>ldp>targeted-session>peer

Description

This command enables the use of the address of a specific interface as the LSR ID to establish a targeted LDP (T-LDP) adjacency and session with one or more non-directly connected LDP peers. The interface can be a regular interface or a loopback interface, including the system interface.

By default, a T-LDP session uses the system interface address as the LSR ID, unless the LSR ID is explicitly configured. This means that T-LDP and interface LDP share a common LDP TCP session and therefore a common LDP label space. The system interface must be always be configured on the router or the LDP protocol does not come up on the node.

At initial configuration, the LDP session to the peers remains down while the interface is down. If the user changes the LSR ID while the LDP session is up, LDP immediately tears down the session and attempts to re-establish it using the new LSR ID. If the interface used for the local LSR ID goes down, the LDP session to all peers using this LSR ID also goes down.

The user-configured LSR ID is used for extended peer discovery to establish the T-LDP hello adjacency. It is also used as the transport address for the LDP TCP session when it is bootstrapped by the T-LDP hello adjacency. The user-configured LSR ID is not used in basic peer discovery to establish a link-level LDP hello adjacency.

The no form of the command resets the local-lsr-id to the default value, which means that the system interface address is used as the LSR ID.

Default

no local-lsr-id

Parameters
interface-name

specifies the name, up to 32 characters in length, of the network IP interface. An interface name cannot be in the form of an IP address. If the string contains special characters (such as #, $, spaces), the entire string must be enclosed within double quotes.

tunneling
Syntax

[no] tunneling

Context

config>router>ldp>targeted-session>peer

Description

This command enables LDP over tunnels.

The no form of the command disables tunneling.

Default

no tunneling

lsp
Syntax

[no] lsp lsp-name

Context

config>router>ldp>targeted-session>peer>tunneling

Description

This command configures an LSP destined for this peer to be used for tunneling an LDP FEC over RSVP-TE. A maximum of four RSVP-TE LSPs can be used for tunneling LDP FECs to the T-LDP peer.

It is not necessary to specify any RSVP-TE LSP in this context unless there is a need to restrict the tunneling to selected LSPs. All RSVP-TE LSPs with a to address matching that of the T-LDP peer are eligible by default. The user can also exclude specific LSP names by using the ldp-over-rsvp exclude command in the config>router>mpls>lsp lsp-name context.

The no form of this command removes the LSP association.

Parameters
lsp-name

specifies the name of the LSP

Show commands

Note: The following command outputs are examples only; actual displays may differ depending on supported functionality and user configuration.
Show router LDP commands
discovery
Syntax

discovery [state state] [detail | summary] [adjacency-type type] [session ip-addr [label-space]]

discovery [state state] [detail | summary] [adjacency-type type] [family]

discovery interface [ip-int-name] [state state] [detail | summary] [session ip-addr [label-space]] [family]

discovery peer [ip-address] [state state] [detail | summary] [session ip-addr [label-space]]

Context

show>router>ldp

Description

This command displays the status of the interfaces participating in LDP discovery.

Parameters
state

specifies the current operational state of the adjacency

Values

established, trying, down

detail

displays detailed information

summary

displays summary information

type

specifies the adjacency type

Values

link, targeted

ip-addr

the IP address of the session

label-space

specifies the label space identifier that the router is advertising on the interface

Values

0 to 65535

family

displays either IPv4 or IPv6 LDP session information

ip-int-name

specifies an existing interface. If the string contains special characters (such as #, $, spaces), the entire string must be enclosed within double quotes.

ip-address

specifies the IP address of the peer

Output

The following outputs are examples of LDP discovery information, and LDP discovery field descriptions describes the fields.

Output example
ALU-12# show router ldp discovery
===============================================================================
LDP IPv4 Hello Adjacencies
===============================================================================
Interface Name                   Local Addr      Peer Addr       AdjType State
-------------------------------------------------------------------------------
N/A                              10.10.10.103    10.10.10.93     Targ    Trying
N/A                              10.10.10.103    10.10.10.104    Targ    Estab
to-104                           10.0.0.103      224.0.0.2       Link    Trying
-------------------------------------------------------------------------------
No. of Hello Adjacencies: 3
===============================================================================
ALU-12#
Output example - show router ldp discovery detail
ALU-12# show router ldp discovery detail
===============================================================================
LDP IPv4 Hello Adjacencies (Detail)
===============================================================================
Peer 10.10.10.93
-------------------------------------------------------------------------------
Local Address      : 10.10.10.103       Peer Address       : 10.10.10.93
Adjacency Type     : Targeted           State              : Trying

-------------------------------------------------------------------------------
Peer 10.10.10.104
-------------------------------------------------------------------------------
Local Address      : 10.10.10.103       Peer Address       : 10.10.10.104
Adjacency Type     : Targeted           State              : Established
Up Time            : 0d 18:26:36        Hold Time Remaining: 38
Hello Mesg Recv    : 76616920           Hello Mesg Sent    : 466580812
Remote Cfg Seq No  : 159                Remote IPv4 Address  : 198.51.100.255
Local Cfg Seq No   : 1674451            Local IPv4  Address  : 198.51.100.1
-------------------------------------------------------------------------------
Interface "to-104"
-------------------------------------------------------------------------------
Local Address      : 10.0.0.103         Peer Address       : 224.0.0.2
Adjacency Type     : Link               State              : Trying

===============================================================================
ALU-12#
Table 5. LDP discovery field descriptions

Label

Description

Interface Name

The name of the interface

Local Addr

The IP address of the originating (local) router

Peer Addr

The IP address of the peer

Adj Type

The adjacency type between the LDP peer and LDP session

State

Established — indicates that the adjacency is established

Trying — indicates that the adjacency is not yet established

No. of Hello Adjacencies

The total number of hello adjacencies discovered

Up Time

The amount of time the adjacency has been enabled

Hold-Time Remaining

The time left before a neighbor is declared to be down

Hello Mesg Recv

The number of Hello messages received for this adjacency

Hello Mesg Sent

The number of Hello messages that have been sent for this adjacency

Remote Cfg Seq No

The configuration sequence number that was in the Hello message received when this adjacency started up. This configuration sequence number changes when there is a change of configuration.

Remote IP Address

The IP address used on the remote end for the LDP session

Local Cfg Seq No

The configuration sequence number that was used in the Hello message sent when this adjacency started up. This configuration sequence number changes when there is a change of configuration.

Local IPv4 Address

Local IPv6 Address

The IP address used locally for the LDP session

fec-egress-stats
Syntax

fec-egress-stats [ip-prefix/mask]

fec-egress-stats [active] [family]

Context

show>router>ldp

Description

This command displays LDP FEC egress statistical information.

Parameters
ip-prefix[/mask]

the IP prefix and prefix length associated with the prefix FEC

Values

ipv4-prefix:

a.b.c.d

ipv4-prefix-length:

32

ipv6-prefix:

x:x:x:x:x:x:x:x (eight 16-bit pieces)

x:x:x:x:x:x:d.d.d.d

x - [0 to FFFF]H

d - [0 to 255]D

ipv6-prefix-length:

128

active

displays information from all LDP FECs with statistics collection enabled

family

displays either IPv4 or IPv6 LDP information

Values

ipv4 or ipv6

Output

The following output is an example of LDP FEC egress statistical information.

Output example
e.show>router>ldp>bindings>fec-egress-stats 2.2.2.2/32
========================================================================
LDP Egress Statistics 
========================================================================
-------------------------------------------------------------------------------
FEC Prefix/Mask    : 10.10.10.29/32
-------------------------------------------------------------------------------
Collect Stats      : Disabled             Accounting Plcy.     : None
Admin State        : Up                   
FC BE
InProf Pkts        : 0                    OutProf Pkts         : 0
InProf Octets      : 0                    OutProf Octets       : 0
FC L2
InProf Pkts        : 0                    OutProf Pkts         : 0
InProf Octets      : 0                    OutProf Octets       : 0
FC AF
InProf Pkts        : 0                    OutProf Pkts         : 0
InProf Octets      : 0                    OutProf Octets       : 0
FC L1
InProf Pkts        : 0                    OutProf Pkts         : 0
InProf Octets      : 0                    OutProf Octets       : 0
FC H2
InProf Pkts        : 0                    OutProf Pkts         : 0
InProf Octets      : 0                    OutProf Octets       : 0
FC EF
InProf Pkts        : 0                    OutProf Pkts         : 0
InProf Octets      : 0                    OutProf Octets       : 0
FC H1
InProf Pkts        : 0                    OutProf Pkts         : 0
InProf Octets      : 0                    OutProf Octets       : 0
FC NC
InProf Pkts        : 0                    OutProf Pkts         : 0
InProf Octets      : 0                    OutProf Octets       : 0
------------------------------------------------------------------------
LDP Egress Statistics : 1
========================================================================
fec-originate
Syntax

fec-originate [ip-address/mask] [operation-type]

fec-originate [operation-type] [family]

Context

show>router>ldp

Description

This command displays LDP static prefix FECs.

Parameters
ip-address/mask

specifies the IP prefix and prefix length

Values

ipv4-address a.b.c.d (host bits must be 0)

mask 0 to 32

operation-type

specifies the operation type to display

Values

pop | swap

family

the address family filter

Values

ipv4 or ipv6

Output

The following output is an example of FEC originate information, and FEC-originate field descriptions describes the fields.

Output example
*A:ALU-12# show router ldp fec-originate
===============================================================================
LDP Static Prefix FECs
===============================================================================
Prefix             NHType  NextHop       IngLabel     EgrLabel   OperIngLabel
-------------------------------------------------------------------------------
10.1.0.0/16         Pop     n/a           --           --        0
10.1.0.1/32         Pop     n/a           --           --        0
10.1.0.2/32         Pop     n/a           --           --        0
10.1.0.3/32         Pop     n/a           --           --        0
10.1.0.4/32         Pop     n/a           --           --        0
10.1.0.5/32         Pop     n/a           --           --        0
10.1.0.6/32         Pop     n/a           --           --        0
10.1.0.7/32         Pop     n/a           --           --        0
10.1.0.8/32         Pop     n/a           --           --        0
10.1.0.9/32         Pop     n/a           --           --        0
...
10.251.0.0/16       Pop     n/a           --           --        0
10.252.0.0/16       Pop     n/a           --           --        0
10.253.0.0/16       Pop     n/a           --           --        0
10.254.0.0/16       Pop     n/a           --           --        0
-------------------------------------------------------------------------------
No. of FECs: 508
===============================================================================

===============================================================================
LDP IPv6 Static Prefix FECs
===============================================================================
Prefix             NHType  NextHop       IngLabel     EgrLabel   OperIngLabel
-------------------------------------------------------------------------------
No Matching Entries Found
===============================================================================
*A:ALU-12#
Table 6. FEC-originate field descriptions

Label

Description

Prefix

The static prefix FEC

NHType

The type of next hop for this entry:

Unknown: the next-hop type has not been set

IP Addr: the next hop is an IP address

Pop: there is no next hop; label is popped and packet routed

Unnumbered: the next hop is an unnumbered interface

Next Hop

The IP address of the next hop, or Unnumbered for unnumbered interfaces

IngLabel

The label that is advertised to the upstream peer. If this variable is set to the default value of 4294967295, the ingress label is dynamically assigned by the label manager.

EgrLabel

The egress label associated with this next-hop entry. The LSR swaps the incoming label with the configured egress label. If this egress label has a value of 4294967295, the LSR pops the incoming label.

OperIngLabel

The actual or operational value of the label that was advertised to the upstream peer

interface
Syntax

interface [ip-int-name | ip-address] [detail]

Context

show>router>ldp

Description

This command displays configuration information about LDP interfaces.

Parameters
ip-int-name

specifies an existing interface. If the string contains special characters (such as #, $, spaces), the entire string must be enclosed within double quotes.

ip-address

identifies the LDP neighbor by IP address

detail

displays detailed information

Output

The following output is an example of LDP interface information, and LDP interface field descriptions describes the fields.

Output example
A:ALU-12# show router ldp interface
===============================================================================
LDP Interfaces
===============================================================================
Interface                   Adm/Opr   Hello  Hold  KA     KA      Transport
 Sub-Interface<s>            Adm/Opr  Fctr   Time  Fctr   Time    Address
-------------------------------------------------------------------------------
ip-10.10.1.1                  Up/Up    
   ipv4                       Up/Dwn  3      15    3      30      System
   ipv6                       Up/Dwn  3      15    3      30      System
-------------------------------------------------------------------------------
No. of Interfaces: 1
===============================================================================
A:ALU-12# 
A:ALU-12>show>router>ldp# interface detail
===============================================================================
LDP Interfaces (Detail)
===============================================================================
-------------------------------------------------------------------------------
Interface "back"
-------------------------------------------------------------------------------
-------------------------------------------------------------------------------
BASE
-------------------------------------------------------------------------------
Admin State        : Up                  Oper State       : Down
BFD Status         : ipv4
-------------------------------------------------------------------------------
IPv4
-------------------------------------------------------------------------------
IPv4 Admin State:    Up                  IPv4 Oper State   : Down
IPv4 Oper Down Rea*: interfaceDown
Hold Time          : 1000                Hello Factor     : 15
Keepalive Timeout  : 1000                Keepalive Factor : 15
Transport Addr     : System              Last Modified    : 08/08/2007 09:50:15
Active Adjacencies : 0
Tunneling          : Disabled
Lsp Name           : None

===============================================================================
A:ALU-12>show>router>ldp#
Table 7. LDP interface field descriptions

Label

Description

Interface

The interface associated with the LDP instance

Adm

Up — indicates that the LDP is administratively enabled

Down — indicates that the LDP is administratively disabled

Opr

Up — indicates that the LDP is operationally enabled

Down — indicates that the LDP is operationally disabled

Hello Fctr

The value by which the hello timeout should be divided to give the hello time; that is, the time interval, in seconds, between LDP Hello messages. LDP uses hello messages to discover neighbors and to detect loss of connectivity with its neighbors.

Hold Time

The time interval, in seconds, that LDP waits before declaring a neighbor to be down. Hold time (also known as Hello time) is local to the system and is sent in the hello messages to a neighbor.

KA Fctr

The value by which the keepalive timeout should be divided to give the keepalive time; that is, the time interval, in seconds,

between LDP keepalive messages. LDP keepalive messages are sent to keep the LDP session from timing out when no other LDP traffic is being sent between the neighbors.

KA Time

The time interval, in seconds, that LDP waits before tearing down a session. If no LDP messages are exchanged during this time interval, the LDP session is torn down. Generally the value is configured to be three times the keepalive time (the time interval between successive LDP keepalive messages).

Transport Address

The transport address entity

No. of Interfaces

The total number of LDP interfaces

Oper Down Reason

The reason for the LSP being in the down state

Active Adjacencies

The number of active adjacencies

Last Modified

The time of the last modification to the LDP interface

Lsp Name

The LSP name

parameters
Syntax

parameters

Context

show>router>ldp

Description

This command displays configuration information about LDP parameters.

Output

The following output is an example of LDP parameters information, and LDP parameters field descriptions describes the fields.

Output example
A:ALU-12# show router ldp parameters             
===============================================================================
LDP Parameters (IPv4 LSR ID 10.20.1.1:0)
               (IPv6 LSR ID 3ffe::a14:101[0])
===============================================================================
-------------------------------------------------------------------------------
Graceful Restart Parameters
-------------------------------------------------------------------------------
Graceful Restart   : Disabled           
Nbor Liveness Time : 120 sec            Max Recovery Time   : 120
-------------------------------------------------------------------------------
IPv4 Interface Parameters
-------------------------------------------------------------------------------
Keepalive Timeout  : 30 sec             Keepalive Factor    : 3
Hold Time          : 15 sec             Hello Factor        : 3
Transport Address  : system             
-------------------------------------------------------------------------------
IPv6 Interface Parameters
-------------------------------------------------------------------------------
Keepalive Timeout  : 30 sec             Keepalive Factor    : 3
Hold Time          : 15 sec             Hello Factor        : 3
Transport Address  : system             
-------------------------------------------------------------------------------
Targeted Session Parameters
-------------------------------------------------------------------------------
Import Pfx Policies: None               Export Pfx Policies : None
Prefer Tunl-in-Tunl: Disabled           SDP Auto Targ Sess  : Enabled
-------------------------------------------------------------------------------
IPv4 Targeted Session Parameters
-------------------------------------------------------------------------------
Keepalive Timeout  : 30 sec             Keepalive Factor    : 3
Hold Time          : 15 sec             Hello Factor        : 3
Hello Reduction    : Disabled           Hello Reduction Fctr: 3
-------------------------------------------------------------------------------
IPv6 Targeted Session Parameters
-------------------------------------------------------------------------------
Keepalive Timeout  : 40 sec             Keepalive Factor    : 4
Hold Time          : 45 sec             Hello Factor        : 3
Hello Reduction    : Disabled           Hello Reduction Fctr: 3
===============================================================================
A:ALU-12A# 
Table 8. LDP parameters field descriptions

Label

Description

Graceful Restart Parameters

Nbor Liveliness Time

The neighbor liveness time

Max Recovery Time

The local maximum recovery time

IPv4 Interface Parameters

IPv6 Interface Parameters

Keepalive Timeout

The time interval, in seconds, that LDP waits before tearing down a session. If no LDP messages are exchanged during this time interval, the LDP session is torn down. Generally the value is configured to be three times the keepalive time (the time interval between successive LDP keepalive messages).

Keepalive Factor

The value by which the keepalive timeout should be divided to give the keepalive time; that is, the time interval, in seconds, between LDP keepalive messages. LDP keepalive messages are sent to keep the LDP session from timing out when no other LDP traffic is being sent between the neighbors.

Hold Time

The time interval, in seconds, that LDP waits before declaring a neighbor to be down. Hold time (also known as Hello time) is local to the system and is sent in the hello messages to a neighbor.

Hello Factor

The value by which the hello timeout should be divided to give the hello time; that is, the time interval, in seconds, between LDP Hello messages. LDP uses hello messages to discover neighbors and to detect loss of connectivity with its neighbors.

Propagate Policy

Specifies whether the LSR should generate FECs and which FECs it should generate

system — indicates that the LDP distributes label bindings only for the router’s system IP address

interface — indicates that the LDP distributes label bindings for all LDP interfaces

all — indicates that the LDP distributes label bindings for all prefixes in the routing table

none — indicates that the LDP does not distribute any label bindings

Transport Address

interface — the interface IP address is used to set up the LDP session between neighbors. If multiple interfaces exist between two neighbors, the interface mode cannot be used because only one LDP session is actually set up between the two neighbors.

system — the system IP address is used to set up the LDP session between neighbors

Label-Distribution

The label distribution method

Label-Retention

liberal — all advertised label mappings are retained whether they are from a valid next hop or not. When the label distribution value is downstream unsolicited, a router may receive label bindings for the same destination for all its neighbors. Labels for the non-next-hops for the FECs are retained in the software but not used. When a network topology change occurs where a non-next-hop becomes a true next hop, the label received earlier is then used.

conservative — advertised label mappings are retained only if they are used to forward packets; for example if the label came from a valid next hop. Label bindings received from non-next-hops for each FEC are discarded.

Control Mode

ordered — label bindings are not distributed in response to a label request until a label binding has been received from the next hop for the destination

independent — label bindings are distributed immediately in response to a label request even if a label binding has not yet been received from the next hop for the destination

Route Preference

The route preference assigned to LDP routes. When multiple routes are available to a destination, the route with the lowest preference is used. This value is only applicable to LDP interfaces and not for targeted sessions.

IPv4 Targeted Session Parameters

IPv6 Targeted Session Parameters

Keepalive Timeout

The factor used to derive the keepalive interval

Keepalive Factor

The time interval, in seconds, that LDP waits before tearing down the session

Hold Time

The time left before a neighbor is declared to be down

Hello Factor

The value by which the hello timeout should be divided to give the hello time; that is, the time interval, in seconds, between LDP Hello messages. LDP uses hello messages to discover neighbors and to detect loss of connectivity with its neighbors.

Disable — indicates that no authentication is being used

Passive Mode

True — indicates that LDP responds only when it gets a connect request from a peer and does not attempt to actively connect to its neighbors

False — indicates that LDP actively tries to connect to its peers

Targeted Sessions

Enabled — indicates that targeted sessions are enabled

Disabled — indicates that targeted sessions are disabled

session
Syntax

session [ip-addr [:label-space]] local-addresses [sent | recv] ip-addr ip-address

session [ip-addr [:label-space]] [session-type] [state state] [detail | summary]

session [ip-addr [:label-space]] local-addresses [sent | recv] [family]

session [ip-addr [:label-space]] statistics [packet-type] [session-type]

session statistics [packet-type] [session-type] [family]

session [session-type] [state state] [detail | summary] [family]

Context

show>router>ldp

Description

This command displays configuration information about LDP sessions.

Parameters
ip-addr

specifies the IP address of the LDP peer

label-space

specifies the label space identifier that the router is advertising on the interface

Values

0 to 65535

detail

displays detailed information

summary

displays summary information

ip-address

specifies the IP address

state

specifies the current operational state of the adjacency

Values

established, trying, down

packet-type

specifies the packet type

Values

hello, keepalive, init, label, notification, address

family

displays either IPv4 or IPv6 LDP session information

session-type

specifies the session type

Values

link, targeted, both

Output

The following output is an example of LDP session information, and LDP session field descriptions describes the fields.

Output example
ALU-12# show router ldp session
===============================================================================
LDP IPv4 Sessions
===============================================================================
Peer LDP Id           Adj Type State        Msg Sent  Msg Recv  Up Time
-------------------------------------------------------------------------------
10.10.10.104:0        Targeted Established  13943      13947      0d 21:12:41
-------------------------------------------------------------------------------
No. of IPv4 Sessions: 1

===============================================================================
LDP IPv6 Sessions
===============================================================================
Peer LDP Id                                                       
 Adj Type             State          Msg Sent       Msg Recv       Up Time
-------------------------------------------------------------------------------
3ffe::a14:102[0]
  Link                Established    1788           1792           0d 01:19:19
3ffe::a14:103[0]
  Link                Established    1789           1788           0d 01:19:19
-------------------------------------------------------------------------------
No. of IPv6 Sessions: 2
===============================================================================
ALU-12#
ALU-12# show router ldp session detail
================================================================
LDP IPv4 Sessions (Detail)
================================================================
Session with Peer 10.1.1.33:0
------------------------------------------------------------------------------
Adjacency Type    : Link           State                 : Established
Up Time           : 0d 00:03:51
Max PDU Length    : 4096           KA/Hold Time Remaining: 26
Link Adjacencies  : 1              Targeted Adjacencies  : 0
Local Address     : 10.1.1.30      Peer Address          : 10.1.1.33
Local TCP Port    : 646            Peer TCP Port         : 50232
Local KA Timeout  : 30             Peer KA Timeout       : 30
Mesg Sent         : 89             Mesg Recv             : 126
FECs Sent         : 3              FECs Recv             : 3
GR State          : Not Capable
Nbr Liveness Time : 0              Max Recovery Time     : 0
Number of Restart : 0              Last Restart Time     : Never
Advertise         : Address
------------------------------------------------------------------------------
Session with Peer 10.1.1.57:0
------------------------------------------------------------------------------
Adjacency Type    : Targeted       State                 : Established
Up Time           : 0d 00:03:49
Max PDU Length    : 4096           KA/Hold Time Remaining: 36
Link Adjacencies  : 0              Targeted Adjacencies  : 1
Local Address     : 10.1.1.30      Peer Address          : 10.1.1.57
Local TCP Port    : 646            Peer TCP Port         : 49574
Local KA Timeout  : 40             Peer KA Timeout       : 40
Mesg Sent         : 55             Mesg Recv             : 61
FECs Sent         : 11             FECs Recv             : 8
GR State          : Not Capable
Nbr Liveness Time : 0              Max Recovery Time     : 0
Number of Restart : 0              Last Restart Time     : Never
Advertise         : Address/Servi*
================================================================
ALU-12#
Table 9. LDP session field descriptions

Label

Description

Peer LDP Id

The IP address of the LDP peer

Adj Type

The adjacency type between the LDP peer and LDP session that is targeted

Link — specifies that this adjacency is a result of a Link Hello

Targeted — specifies that this adjacency is a result of a Targeted Hello

State

Established — the adjacency is established

Trying — the adjacency is not yet established

Msg Sent

The number of messages sent

Msg Rcvd

The number of messages received

Up Time

The amount of time the adjacency has been enabled

session-parameters
Syntax

session-parameters [family]

session-parameters [peer-ip-address]

Context

show>router>ldp

Description

This command displays LDP peer information.

Parameters
family

the address family filter

Values

ipv4 or ipv6

peer-ip-address

specifies the peer IP address

Output

The following output is an example of LDP session-parameters information.

Output example
A:ALU-12# show router ldp session-parameters
===============================================================================
LDP IPv4 Session Parameters
===============================================================================
-------------------------------------------------------------------------------
Peer : 10.2.3.4
-------------------------------------------------------------------------------
DOD                : Disabled           Adv Adj Addr Only  : Disabled
FEC129             : Disabled
Fec Limit          : 0                  Fec Limit Threshold: 90
Fec Limit Log Only : Disabled
Import Policies    : None               Export Policies    : None
IPv4 Prefix Fec Cap: Enabled            IPv6 Prefix Fec Cap: Enabled
P2MP Fec Cap       : Enabled
Address Export     : None
===============================================================================
No. of IPv4 Peers: 1
===============================================================================
* indicates that the corresponding row element may have been truncated.
===============================================================================
LDP IPv6 Session Parameters
===============================================================================
No Matching Entries Found
===============================================================================
status
Syntax

status

Context

show>router>ldp

Description

This command displays LDP status information.

Output

The following output is an example of LDP status information, and LDP status field descriptions describes the fields.

Output example
A:ALU-12# show router ldp status

 ===============================================================================
 LDP Status for IPv4 LSR ID 2.2.2.2
                IPv6 LSR ID ::
 ===============================================================================
 Created at         : 10/18/17 13:08:17    
 Last Change        : 10/18/17 13:08:17    
 Admin State        : Up                   
 IPv4 Oper State    : Up                   IPv6 Oper State      : Up
 IPv4 Up Time       : 1d 01:35:18          IPv6 Up Time         : 1d 01:35:18
 IPv4 Oper Down Rea*: n/a                  IPv6 Oper Down Reason: n/a
 IPv4 Oper Down Eve*: 0                    IPv6 Oper Down Events: 0
 Tunn Down Damp Time: 3 sec                Weighted ECMP        : Disabled
 Label Withdraw Del*: 0 sec                Implicit Null Label  : Disabled
 Short. TTL Local   : Enabled              Short. TTL Transit   : Enabled
 ConsiderSysIPByPol*: Disabled             
 Import Policies    : None                 Export Policies      : None
 Tunl Exp Policies  : None                 
 FRR                : Disabled             Mcast Upstream FRR   : Disabled
 Mcast Upst ASBR FRR: Disabled             
 MP MBB Time        : 3                    
 Aggregate Prefix   : False                Agg Prefix Policies  : None
 Class Forwarding   : Disabled             
 Legacy LSR Interop : False                
 Entropy Label Capa*: False                
 Generate Basic FEC : Disabled             
 Resolve Via Mcast *: Disabled             
 -------------------------------------------------------------------------------
 Capabilities
 -------------------------------------------------------------------------------
 Dynamic            : Enabled              P2MP                 : Enabled
 IPv4 Prefix Fec    : Enabled              IPv6 Prefix Fec      : Enabled
 Service Fec128     : Enabled              Service Fec129       : Enabled
 MP MBB             : Enabled              Overload             : Enabled
 Unrecognized Notif*: Enabled              
 ===============================================================================
 * indicates that the corresponding row element may have been truncated.
Table 10. LDP status field descriptions

Label

Description

Created at

The date and time that the LDP instance was created

Last Change

The date and time that the LDP instance was last modified

Admin State

Up — indicates that LDP is administratively enabled

Down — indicates that LDP is administratively disabled

IPv4 Oper State

IPv6 Oper State

Up — indicates that LDP is operationally enabled

Down — indicates that LDP is operationally disabled

IPv4 Up Time

IPv6 Up Time

The time, in hundredths of seconds, that the LDP instance has been operationally up

IPv4 Oper Down Time

IPv6 Oper Down Time

The time, in hundredths of seconds, that the LDP instance has been operationally down

IPv4 Oper Down Events

IPv6 Oper Down Events

The number of times the LDP instance has gone operationally down since the instance was created

Import Policies

The import policy associated with the LDP instance

Active Adjacencies

The number of active adjacencies (established sessions) associated with the LDP instance

Active Sessions

The number of active sessions (session in some form of creation)

associated with the LDP instance

Active Interfaces

The number of active (operationally up) interfaces associated with the LDP instance

Inactive Interfaces

The number of inactive (operationally down) interfaces associated with the LDP instance

Active Peers

The number of active LDP peers

Inactive Peers

The number of inactive LDP peers

Addr FECs Sent

The number of labels that have been sent to the peer associated with this FEC

Addr FECs Recv

The number of labels that have been received from the peer associated with this FEC

Serv FECs Sent

The number of labels that have been sent to the peer associated with this FEC

Serv FECs Recv

The number of labels that have been received from the peer associated with this FEC

Attempted Sessions

The total number of attempted sessions for this LDP instance

No Hello Err

The total number of ‟Session Rejected” or ‟No Hello Error” notification messages sent or received by this LDP instance

Param Adv Err

The total number of ‟Session Rejected” or ‟Parameters Advertisement Mode Error” notification messages sent or received by this LDP instance

Max PDU Err

The total number of ‟Session Rejected” or ‟Parameters Max PDU Length Error” notification messages sent or received by this LDP instance

Label Range Err

The total number of ‟Session Rejected” or ‟Parameters Label Range Error” notification messages sent or received by this LDP instance

Bad LDP Id Err

The number of bad LDP identifier fatal errors detected for sessions associated with this LDP instance

Bad PDU Len Err

The number of bad PDU length fatal errors detected for sessions associated with this LDP instance

Bad Mesg Len Err

The number of bad message length fatal errors detected for sessions associated with this LDP instance

Bad TLV Len Err

The number of bad TLV length fatal errors detected for sessions associated with this LDP instance

Malformed TLV Err

The number of malformed TLV value fatal errors detected for sessions associated with this LDP instance

Keepalive Expired Err

The number of session keepalive timer expired errors detected for sessions associated with this LDP instance

Shutdown Notif Sent

The number of shutdown notifications sent related to sessions associated with this LDP instance

Shutdown Notif Recv

The number of shutdown notifications received related to sessions associated with this LDP instance

targ-peer
Syntax

targ-peer [ip-address] [detail]

targ-peer [detail] [family]

Context

show>router>ldp

Description

This command displays configuration information about LDP targeted peers.

Parameters
ip-address

specifies the IP address of the LDP peer

detail

displays detailed information

family

the address family filter

Values

ipv4 or ipv6

Output

The following output is an example of LDP peer information, and LDP targeted peer field descriptions describes the fields.

Output example
A:ALU-12# show router ldp targ-peer
===============================================================================
LDP IPv4 Targeted Peers
===============================================================================
Peer                 Adm/   Hello   Hold    KA      KA       Passive   Auto
                     Opr    Fctr    Time    Fctr    Time     Mode      Created
-------------------------------------------------------------------------------
10.10.10.93          Up/Up  3       45      4       40       Disabled  Yes
10.10.10.104         Up/Up  3       45      4       40       Disabled  Yes
-------------------------------------------------------------------------------
No. of IPv4 Targeted Peers: 2
===============================================================================

===============================================================================
LDP IPv6 Targeted Peers
===============================================================================
Peer                                    Adm/    Hello Hold  KA   KA    Auto
                                        Opr     Fctr  Time  Fctr Time  Created
-------------------------------------------------------------------------------
3ffe::a0a:203                        Up/Up   3     15    3    30    no

-------------------------------------------------------------------------------
No. of IPv6 Targeted Peers: 1
===============================================================================
A:ALU-12#
A:ALU-12# show router ldp targ-peer detail
===============================================================================
LDP IPv4 Targeted Peers (Detail)
===============================================================================
-------------------------------------------------------------------------------
Peer 10.2.3.4
-------------------------------------------------------------------------------
Admin State        : Up              Oper State           : Down
Hold Time          : 45              Hello Factor         : 3
Keepalive Timeout  : 40              Keepalive Factor     : 4
Passive Mode       : Disabled        Last Modified        : 05/01/2008 21:44:17
Active Adjacencies : 0               Auto Created         : No
Tunneling          : None
Lsp Name           : None
===============================================================================
No. of IPv4 Targeted Peers: 1
===============================================================================

===============================================================================
LDP IPv6 Targeted Peers
===============================================================================
No Matching Entries Found
===============================================================================
A:ALU-12#
Table 11. LDP targeted peer field descriptions

Label

Description

Peer

The IP address of the peer

Adm

Up — indicates that LDP is administratively enabled

Down — indicates that LDP is administratively disabled

Opr

Up — indicates that LDP is operationally enabled

Down — indicates that LDP is operationally disabled

Hello Factor

The value by which the hello timeout should be divided to give the hello time; that is, the time interval, in seconds, between LDP Hello messages. LDP uses hello messages to discover neighbors and to detect loss of connectivity with its neighbors.

Hold Time

The time interval, in seconds, that LDP waits before declaring a neighbor to be down. Hold time (also known as Hello time) is local to the system and is sent in the hello messages to a neighbor.

Keepalive Factor

The value by which the keepalive timeout should be divided to give the keepalive time; that is, the time interval, in seconds,

between LDP keepalive messages. LDP keepalive messages are sent to keep the LDP session from timing out when no other LDP traffic is being sent between the neighbors.

Keepalive Timeout

The time interval, in seconds, that LDP waits before tearing down a session. If no LDP messages are exchanged during this time interval, the LDP session is torn down. Generally the value is configured to be three times the keepalive time (the time interval between successive LDP keepalive messages).

Passive Mode

The mode used to set up LDP sessions. This value is only applicable to targeted sessions and not to LDP interfaces. This mode is always set to False.

True — indicates that LDP responds only when it gets a connect request from a peer and does not attempt to actively connect to its neighbors

False — indicates that LDP actively tries to connect to its peers

Auto Create

Specifies whether a targeted peer was automatically created through a Service Manager. For an LDP interface, this value is always false.

No. of Peers

The total number of LDP peers

LSP

The LSP name

tcp-session-parameters
Syntax

tcp-session-parameters [family]

tcp-session-parameters [keychain keychain]

tcp-session-parameters transport-peer-ip-address

Context

show>router>ldp

Description

This command displays information about the TCP transport session of an LDP peer.

Parameters
family

displays either IPv4 or IPv6 LDP session information

keychain

specifies the authentication keychain name up to 32 characters in length

Values

ipv4 or ipv6

transport-peer-ip-address

specifies the IP address of the transport peer

Output

The following output is an example of TCP session parameter information.

Output example
*A:Dut-A# show router ldp tcp-session-parameters
===============================================================================
LDP IPv4 TCP Session Parameters
===============================================================================
-------------------------------------------------------------------------------
Peer Transport: 10.20.1.2
-------------------------------------------------------------------------------
Authentication Key : Disabled Path MTU Discovery : Disabled
Auth key chain : LdpAuth Min-TTL : 0
-------------------------------------------------------------------------------
Peer Transport: 10.20.1.3
-------------------------------------------------------------------------------
Authentication Key : Disabled Path MTU Discovery : Disabled
Auth key chain : LdpAuth Min-TTL : 0
===============================================================================
No. of IPv4 Peers: 2
===============================================================================
===============================================================================
LDP IPv6 TCP Session Parameters
===============================================================================
-------------------------------------------------------------------------------
Peer Transport: 3ffe::a14:102
-------------------------------------------------------------------------------
Authentication Key : Disabled Path MTU Discovery : Disabled
Auth key chain : LdpAuth Min-TTL : 0
-------------------------------------------------------------------------------
Peer Transport: 3ffe::a14:103
-------------------------------------------------------------------------------
Authentication Key : Disabled Path MTU Discovery : Disabled
Auth key chain : LdpAuth Min-TTL : 0
===============================================================================
No. of IPv6 Peers: 2
===============================================================================
Show router LDP bindings commands
bindings
Syntax

bindings

Context

show>router>ldp

Description

This command shows LDP bindings information. The bindings command can be used with the following keywords:

  • active: displays LDP active bindings

  • detail: displays details of LDP bindings

  • ipv4: displays LDP IPv4 bindings

  • ipv6: displays LDP IPv6 bindings

  • label-type: displays LDP FEC bindings by matching labels

  • p2mp: displays LDP P2MP FEC bindings

  • prefixes: displays LDP prefix FEC bindings

  • services: displays LDP service FEC bindings

  • session: displays LDP FEC bindings by matching peer LSR ID

  • summary: displays summary of LDP bindings

Output

The following output is an example of LDP bindings parameter information, and LDP bindings field descriptions describes the fields.

Output example
*A:Sar18 Dut-B>show>router>ldp# bindings 
===============================================================================
LDP Bindings (IPv4 LSR ID 2.2.2.2)
             (IPv6 LSR ID ::)
===============================================================================
Legend: U - Label In Use, N - Label Not In Use, W - Label Withdrawn
        S - Status Signaled Up,  D - Status Signaled Down
        E - Epipe Service, V - VPLS Service, M - Mirror Service
        A - Apipe Service, F - Fpipe Service, I - IES Service, R - VPRN service
        P - Ipipe Service, WP - Label Withdraw Pending, C - Cpipe Service
        BU - Alternate For Fast Re-Route, TLV - (Type, Length: Value), 
                                          H - Hpipe Service
        LF - Lower FEC, UF - Upper FEC
===============================================================================
LDP IPv4 Prefix Bindings 
===============================================================================
Prefix                                      IngLbl                    EgrLbl
Peer                                        EgrIntf/LspId
EgrNextHop
-------------------------------------------------------------------------------
10.1.1.1/32                                    --                      131071
10.1.1.1:0                                  1/1/1:100
10.1.1.1
10.2.2.2/32                                 131071U                     --
10.1.1.1:0                                     --
  --
-------------------------------------------------------------------------------
No. of IPv4 Prefix Bindings: 2
===============================================================================
===============================================================================
LDP IPv6 Prefix Bindings
===============================================================================
Prefix                                      IngLbl                    EgrLbl
Peer                                        EgrIntf/LspId             
EgrNextHop                                                            
-------------------------------------------------------------------------------
3ffe::a14:101/128                           262142U                     --
3ffe::a14:102[0]                              --                      
-------------------------------------------------------------------------------
No. of IPv6 Prefix Bindings: 2
===============================================================================
===============================================================================
LDP Generic IPv4 P2MP Bindings
===============================================================================
P2MP-Id
RootAddr                                    Interface       IngLbl    EgrLbl
EgrNH                                       EgrIf/LspId
Peer
-------------------------------------------------------------------------------
No Matching Entries Found
===============================================================================
===============================================================================
LDP Generic IPv6 P2MP Bindings
===============================================================================
P2MP-Id
RootAddr                                    Interface       IngLbl    EgrLbl
EgrNH                                       EgrIf/LspId
Peer
-------------------------------------------------------------------------------
No Matching Entries Found
===============================================================================
===============================================================================
LDP In-Band-SSM IPv4 P2MP Bindings
===============================================================================
Source
Group
RootAddr                                    Interface       IngLbl    EgrLbl
EgrNH                                       EgrIf/LspId
Peer
-------------------------------------------------------------------------------
No Matching Entries Found
===============================================================================
===============================================================================
LDP In-Band-SSM IPv6 P2MP Bindings
===============================================================================
Source
Group
RootAddr                                    Interface       IngLbl    EgrLbl
EgrNH                                       EgrIf/LspId
Peer
-------------------------------------------------------------------------------
No Matching Entries Found
===============================================================================
===============================================================================
LDP In-Band-VPN-SSM IPv4 P2MP Bindings
===============================================================================
Source
Group                                       RD
RootAddr                                    Interface       IngLbl    EgrLbl
EgrNH                                       EgrIf/LspId
Peer
-------------------------------------------------------------------------------
No Matching Entries Found
===============================================================================
===============================================================================
LDP In-Band-VPN-SSM IPv6 P2MP Bindings
===============================================================================
Source
Group                                       RD
RootAddr                                    Interface       IngLbl    EgrLbl
EgrNH                                       EgrIf/LspId
Peer
-------------------------------------------------------------------------------
No Matching Entries Found
===============================================================================
===============================================================================
LDP Recursive with In-Band-SSM IPv4 P2MP Bindings
===============================================================================
RootAddr
InnerRootAddr
Source
Group                                       Interface       IngLbl    EgrLbl
EgrNH                                       EgrIf/LspId
Peer
-------------------------------------------------------------------------------
No Matching Entries Found
===============================================================================
===============================================================================
LDP Recursive with In-Band-SSM IPv6 P2MP Bindings
===============================================================================
RootAddr
InnerRootAddr
Source
Group                                       Interface       IngLbl    EgrLbl
EgrNH                                       EgrIf/LspId
Peer
-------------------------------------------------------------------------------
No Matching Entries Found
===============================================================================
===============================================================================
LDP VPN Recursive with Generic IPv4 P2MP Bindings
===============================================================================
P2MP-Id                                     RD
RootAddr                                    Interface
InnerRootAddr                                               IngLbl    EgrLbl
EgrNH                                       EgrIf/LspId
Peer
-------------------------------------------------------------------------------
No Matching Entries Found
===============================================================================
===============================================================================
LDP VPN Recursive with Generic IPv6 P2MP Bindings
===============================================================================
P2MP-Id                                     RD
RootAddr                                    Interface
InnerRootAddr                                               IngLbl    EgrLbl
EgrNH                                       EgrIf/LspId
Peer
-------------------------------------------------------------------------------
No Matching Entries Found
===============================================================================
===============================================================================
LDP GRT Recursive with Generic IPv4 P2MP Bindings
===============================================================================
P2MP-Id
RootAddr                                    Interface       IngLbl    EgrLbl
InnerRootAddr
EgrNH                                       EgrIf/LspId
Peer
-------------------------------------------------------------------------------
No Matching Entries Found
===============================================================================
===============================================================================
LDP GRT Recursive with Generic IPv6 P2MP Bindings
===============================================================================
P2MP-Id
RootAddr                                    Interface       IngLbl    EgrLbl
InnerRootAddr
EgrNH                                       EgrIf/LspId
Peer
-------------------------------------------------------------------------------
No Matching Entries Found
===============================================================================
===============================================================================
LDP Service FEC 128 Bindings
===============================================================================
Type                                          VCId       SDPId     IngLbl  LMTU
Peer                                          SvcId                EgrLbl  RMTU
-------------------------------------------------------------------------------
?-Eth                                         10         R. Src      --    None
10.1.1.1:0                                    Ukwn                 131070D 1500
-------------------------------------------------------------------------------
No. of VC Labels: 1
===============================================================================
===============================================================================
LDP Service FEC 129 Bindings
===============================================================================
SAII                                            AGII        IngLbl    LMTU
TAII                                            Type        EgrLbl    RMTU
Peer                                            SvcId       SDPId
-------------------------------------------------------------------------------
No Matching Entries Found
===============================================================================
*A:Sar18 Dut-B>show>router>ldp#
Table 12. LDP bindings field descriptions

Label

Description

Legend

U: Label In Use

N: Label Not In Use

W: Label Withdrawn

S: Status Signaled Up

D: Status Signaled Down

E: Epipe Service

V: VPLS Service

M: Mirror Service

A: Apipe Service

F: Fpipe Service

I: IES Service

R: VPRN service

P: Ipipe Service

WP: Label Withdraw Pending

C: Cpipe Service

BU: Alternate for Fast Re-Route

TLV: (Type, Length: Value)

H: Hpipe

LF: Lower FEC

UF: Upper FEC

Type

The service type exchanging labels in the SDP. The possible types displayed are Epipe, Spoke, and Unknown.

VCId

The value used by each end of an SDP tunnel to identify the VC

SvcID

Identifies the service in the service domain

SDPId

Identifies the SDP in the service domain

Peer

The IP address of the peer

IngLbl

The ingress LDP label

U — indicates that the label is in use

R — indicates that the label has been released

EgrLbl

The egress LDP label

LMTU

The local MTU value

RMTU

The remote MTU value

No. of Prefix Bindings

The total number of LDP bindings on the router

EgrIntf/LspId

The egress interface LSP ID

EgrNextHop

The egress next-hop address, or Unnumbered for unnumbered interfaces

AGI Type

The address group identifier (AGI)

SAII Peer

The source attachment individual identifier (SAII)

TAII EgrLbl

The target attachment individual identifier (TAII)

Prefix

The FEC address

P2MP-Id

The Internal identifier of Point to Multi-point LSP

RootAddr

The Root Address (only IPV4)

Interface

The Logical Interface ID

EgrNH

The egress next-hop address

Source

The Source Address

Group

The Multicast Group address

InnerRootAddr

The Inner Root Address

No. of VC Labels

The total number of VC labels

No. of Service Bindings

The total number of service bindings

Vc-switching

Not applicable – always indicates No

Egr. Flags

Specifies the egress flags, if any

Egr. Ctl Word

Indicates whether egress control words are used

Egr. Status Bits

Indicates whether egress status bits are supported

Egr If Name

The egress interface name

Ing. Flags

Specifies the ingress flags, if any

Ing. Ctl Word

Indicates whether ingress control words are used

Ing. Status Bits

Indicates whether ingress status bits are supported

Metric

The metric of the LSP

Mtu

The size of the MTU for the global FEC or tunnel to which the LDP binding is applied

Op

The operation performed on the ingress or egress label in the LDP stack (push or pop)

active
Syntax

active detail [family][egress-if port-id]

active detail [family][egress-lsp tunnel-id]

active detail [egress-nh ip-address] [family]

active egress-if port-id [summary | detail] [family]

active egress-lsp tunnel-id[summary | detail] [family]

active egress-nh [family] [summary | detail] ip-address

active ipv4 [summary | detail][egress-if port-id]

active ipv4 [summary | detail][egress-lsp tunnel-id]

active ipv4 [summary | detail][egress-nh ip-address]

active ipv6 [summary | detail] [egress-if port-id]

active ipv6 [summary | detail][egress-nh ip-address]

active ipv6 [summary | detail][egress-lsp tunnel-id]

active p2mp p2mp-id identifier root ip-address [summary | detail] [egress-if port-id]

active p2mp p2mp-id identifier root ip-address [summary | detail] [egress-lsp tunnel-id]

active p2mp p2mp-id identifier root ip-address [summary | detail] [egress-nh ip-address]

active p2mp [family] [summary | detail] [egress-if port-id] [opaque-type opaque-type]

active p2mp [family] [summary | detail] [egress-lsp tunnel-id] [opaque-type opaque-type]

active p2mp [family] [summary | detail] [egress-nh ip-address] [opaque-type opaque-type]

active p2mp source ip-address group mcast-address root ip-address [summary | detail] [egress-if port-id] inner-root ip-address

active p2mp source ip-address group mcast-address root ip-address [summary | detail] [egress-lsp tunnel-id] inner-root ip-address

active p2mp source ip-address group mcast-address root ip-address [summary | detail] [egress-nh ip-address] inner-root ip-address

active p2mp source ip-address group mcast-address root ip-address [rd rd] [summary | detail] [egress-if port-id]

active p2mp source ip-address group mcast-address root ip-address [rd rd] [summary | detail] [egress-lsp tunnel-id]

active p2mp source ip-address group mcast-address root ip-address [rd rd] [summary | detail] [egress-nh ip-address]

active p2mp source ip-address group mcast-address family[rd rd] [summary | detail] [innermost-root ip-address]

active prefixes [family] [summary | detail] [egress-if port-id]

active prefixes [family] [summary | detail] [egress-lsp tunnel-id]

active prefixes [egress-nh ip-address] [family] [summary | detail]

active prefixes prefix ip-prefix/ip-prefix-length [summary | detail][egress-if port-id]

active prefixes prefix ip-prefix/ip-prefix-length [summary | detail] [egress-lsp tunnel-id]

active prefixes prefix ip-prefix/ip-prefix-length [egress-nh ip-address] [summary | detail]

active summary [family] [egress-if port-id]

active summary [family] [egress-lsp tunnel-id]

active summary [egress-nh ip-address] [family]

Context

show>router>ldp>bindings

Description

This command displays information about LDP active bindings.

Parameters
detail

displays detailed information

summary

displays information in a summarized format

family

displays either IPv4 or IPv6 active LDP information

Values

ipv4 or ipv6

egress-if port-id

displays LDP active bindings by matching egress-if

Values

slot[/mda[/port]] or slot/mda/port[.channel]

aps-id : aps-group-id[.channel]

group-id : 1 to 24]

mw-link-id : mw-link-link-num

link-num : 1 to 24

egress-lsp tunnel-id

displays LDP active bindings by matching on the egress RSVP-TE LSP tunnel-id for LDP FECs that are tunneled over an RSVP-TE LSP. The tunnel-id for the RSVP-TE LSP can be found in the output of the show router mpls lsp detail command and in the show router tunnel-table command. It is not the Path LSP ID shown in the output of the show router mpls lsp path detail command.

Values

0 to 4294967295

egress-nh ip-address

displays LDP active bindings by matching egress-nh

Values

ipv4-address

a.b.c.d

ipv6-address

x:x:x:x:x:x:x:x (eight 16-bit pieces)

x:x:x:x:x:x:d.d.d.d

x - [0 to FFFF]H

d - [0 to 255]D

opaque-type opaque-type

specifies the type of a multipoint opaque value element

Values

generic, ssm, vpn-ssm, recursive-ssm, vpn-recursive, grt-recursive

inner-root ip-address

displays recursive FECs whose inner root address matches the specified address

innermost-root ip-address

displays recursive FECs whose inner root address matches the specified address and non-recursive FECs that have a root address that matches the specified address

p2mp source ip-address

displays LDP active P2MP source bindings

Values

ipv4-address

a.b.c.d

ipv6-address

x:x:x:x:x:x:x:x (eight 16-bit pieces)

x:x:x:x:x:x:d.d.d.d

x - [0 to FFFF]H

d - [0 to 255]D

p2mp-id identifier

displays LDP active P2MP identifier bindings

Values

0 to 4294967295

group mcast-address

displays the P2MP group multicast address bindings

Values

ipv4-mcast-addr or ipv6-mcast-addr

root ip-address

displays root IP address information

rd rd

displays information for the route distinguisher

Values

rd : ip-addr:comm-val or 2byte-asnumber:ext-comm-val or 4byte-asnumber:comm-val

prefix ip-prefix/ip-prefix-length

displays information for the specified IP prefix and mask length

Values

ipv4-address

a.b.c.d

ipv4-prefix-length

0 to 32

ipv6-address

x:x:x:x:x:x:x:x (eight 16-bit pieces)

x:x:x:x:x:x:d.d.d.d

x - [0 to FFFF]H

d - [0 to 255]D

ipv6-prefix-length

0 to 128

Output

The following output is an example of LDP active bindings information, and LDP bindings field descriptions describes the fields.

Output example
*A:Sar18 Dut-B>show>router>ldp# bindings active
===============================================================================
LDP Bindings (IPv4 LSR ID 10.20.1.3:0)
             (IPv6 LSR ID 3ffe::a14:103[0])
===============================================================================
Legend: U - Label In Use,  N - Label Not In Use, W - Label Withdrawn
        WP - Label Withdraw Pending, BU - Alternate For Fast Re-Route
        LF - Lower FEC, UF - Upper FEC
        (S) - Static           (M) - Multi-homed Secondary Support
        (B) - BGP Next Hop     (BU) - Alternate Next-hop for Fast Re-Route
        (I) - SR-ISIS Next Hop (O) - SR-OSPF Next Hop
===============================================================================
LDP IPv4 Prefix Bindings (Active)
===============================================================================
Prefix                                      Op              IngLbl    EgrLbl
EgrNextHop                                  EgrIf/LspId               
-------------------------------------------------------------------------------
10.20.1.1/32                                Push              --      262143
10.10.2.1                                   1/1/1                      
                                                                       
10.20.1.1/32                                Swap            262141    262143
10.10.2.1                                   1/1/1                      
-------------------------------------------------------------------------------
No. of IPv4 Prefix Active Bindings: 2
===============================================================================
===============================================================================
LDP IPv6 Prefix Bindings (Active)
===============================================================================
Prefix                                         Op              IngLbl    EgrLbl
EgrNextHop                                     EgrIf/LspId               
-------------------------------------------------------------------------------
3ffe::a14:101/128                              Push              --      262142
fe80::21                                       1/1/1                      
                                                                       
3ffe::a14:101/128                              Swap            262136    262142
fe80::21                                       1/1/1                      
-------------------------------------------------------------------------------
No. of IPv6 Prefix Active Bindings: 2
===============================================================================
===============================================================================
LDP In-Band-SSM IPv6 P2MP Bindings (Active)
===============================================================================
Source
Group                                       Interface
RootAddr                                    Op              IngLbl    EgrLbl
EgrNH                                       EgrIf/LspId
-------------------------------------------------------------------------------
No Matching Entries Found
===============================================================================
===============================================================================
LDP Recursive with In-Band-SSM IPv4 P2MP Bindings (Active)
===============================================================================
RootAddr
InnerRootAddr
Source                                      Interface
Group                                       Op              IngLbl    EgrLbl
EgrNH                                       EgrIf/LspId
-------------------------------------------------------------------------------
No Matching Entries Found
===============================================================================
===============================================================================
LDP Recursive with In-Band-SSM IPv6 P2MP Bindings (Active)
===============================================================================
RootAddr
InnerRootAddr
Source                                      Interface
Group                                       Op              IngLbl    EgrLbl
EgrNH                                       EgrIf/LspId
-------------------------------------------------------------------------------
No Matching Entries Found
===============================================================================
===============================================================================
LDP In-Band-VPN-SSM IPv4 P2MP Bindings (Active)
===============================================================================
Source
Group                                       RD              Op
RootAddr                                    Interface       IngLbl    EgrLbl
EgrNH                                       EgrIf/LspId
-------------------------------------------------------------------------------
No Matching Entries Found
===============================================================================
===============================================================================
LDP In-Band-VPN-SSM IPv6 P2MP Bindings (Active)
===============================================================================
Source
Group                                       RD              Op
RootAddr                                    Interface       IngLbl    EgrLbl
EgrNH                                       EgrIf/LspId
-------------------------------------------------------------------------------
No Matching Entries Found
===============================================================================
===============================================================================
VPN Recursive with Generic IPv4 P2MP Bindings (Active)
===============================================================================
P2MP-Id                                     Interface
RootAddr                                    Op              IngLbl    EgrLbl
InnerRootAddr                               RD
EgrNH                                       EgrIf/LspId
-------------------------------------------------------------------------------
No Matching Entries Found
===============================================================================
===============================================================================
LDP VPN Recursive with Generic IPv6 P2MP Bindings (Active)
===============================================================================
P2MP-Id                                     Interface
RootAddr                                    Op              IngLbl    EgrLbl
InnerRootAddr                               RD
EgrNH                                       EgrIf/LspId
-------------------------------------------------------------------------------
No Matching Entries Found
===============================================================================
===============================================================================
LDP GRT Recursive with Generic IPv4 P2MP Bindings (Active)
===============================================================================
P2MP-Id                                     Interface
RootAddr                                    Op              IngLbl    EgrLbl
InnerRootAddr
EgrNH                                       EgrIf/LspId
-------------------------------------------------------------------------------
No Matching Entries Found
===============================================================================
===============================================================================
LDP GRT Recursive with Generic IPv6 P2MP Bindings (Active)
===============================================================================
P2MP-Id                                     Interface
RootAddr                                    Op              IngLbl    EgrLbl
InnerRootAddr
EgrNH                                       EgrIf/LspId
-------------------------------------------------------------------------------
No Matching Entries Found
===============================================================================
*A:Sar18 Dut-B>show>router>ldp#
detail
Syntax

detail [session ip-addr [label-space]] [family]

Context

show>router>ldp>bindings

Description

This command displays details of LDP bindings.

Parameters
family

displays either IPv4 or IPv6 LDP information

session ip-addr[label-space]

specifies the IP address and label space identifier

Values

ip-addr[label-spa* : ipv4-address:label-space

ipv6-address[label-space]

label-space : 0 to 65535]

Output

The following output is an example of detailed LDP bindings information, and LDP bindings field descriptions describes the fields.

Output example
*A:Sar18 Dut-B>show>router>ldp# bindings active detail
===============================================================================
LDP Bindings (IPv4 LSR ID 10.20.1.3:0)
             (IPv6 LSR ID 3ffe::a14:103[0])
===============================================================================
Legend: U - Label In Use,  N - Label Not In Use, W - Label Withdrawn
        WP - Label Withdraw Pending, BU - Alternate For Fast Re-Route
        (S) - Static       (M) - Multi-homed Secondary Support
        (B) - BGP Next Hop (BU) - Alternate Next-hop for Fast Re-Route
==============================================================================
LDP IPv4 Prefix Bindings (Active)
==============================================================================
-------------------------------------------------------------------------------
Prefix         : 10.20.1.1/32
Op             : Push               
Ing Lbl        :   --               Egr Lbl    : 262143
Egr Int/LspId  : 1/1/1              
EgrNextHop     : 10.10.2.1
Egr. Flags     : None               Ing. Flags : None
Egr If Name    : ip-10.10.2.3       
Metric         : 1000               Mtu        : 1500
-------------------------------------------------------------------------------
Prefix         : 10.20.1.1/32
Op             : Swap               
Ing Lbl        : 262141             Egr Lbl    : 262143
Egr Int/LspId  : 1/1/1              
EgrNextHop     : 10.10.2.1
Egr. Flags     : None               Ing. Flags : None
Egr If Name    : ip-10.10.2.3       
Metric         : 1000               Mtu        : 1500
===============================================================================
No. of IPv4 Prefix Active Bindings: 2
==============================================================================

==============================================================================
LDP IPv6 Prefix Bindings (Active)
==============================================================================
-------------------------------------------------------------------------------
Prefix         : 3ffe::a14:101/128
Op             : Push               
Ing Lbl        :   --               Egr Lbl    : 262142
Egr Int/LspId  : 1/1/1              
EgrNextHop     : fe80::21
Egr. Flags     : None               Ing. Flags : None
Egr If Name    : ip-10.10.2.3       
Metric         : 1000               Mtu        : 1500
-------------------------------------------------------------------------------
Prefix         : 3ffe::a14:101/128
Op             : Swap               
Ing Lbl        : 262136             Egr Lbl    : 262142
Egr Int/LspId  : 1/1/1              
EgrNextHop     : fe80::21
Egr. Flags     : None               Ing. Flags : None
Egr If Name    : ip-10.10.2.3       
Metric         : 1000               Mtu        : 1500
-------------------------------------------------------------------------------
===============================================================================
No. of IPv6 Prefix Active Bindings: 2
==============================================================================

==============================================================================
LDP Generic IPv4 P2MP Bindings
==============================================================================
No Matching Entries Found
==============================================================================
==============================================================================
LDP Generic IPv6 P2MP Bindings
==============================================================================
No Matching Entries Found
==============================================================================
==============================================================================
LDP In-Band-SSM IPv4 P2MP Bindings
==============================================================================
No Matching Entries Found
==============================================================================
==============================================================================
LDP In-Band-SSM IPv6 P2MP Bindings
==============================================================================
No Matching Entries Found
==============================================================================
==============================================================================
LDP In-Band-VPN-SSM IPv4 P2MP Bindings
==============================================================================
No Matching Entries Found
==============================================================================
==============================================================================
LDP In-Band-VPN-SSM IPv6 P2MP Bindings
==============================================================================
No Matching Entries Found
==============================================================================
==============================================================================
LDP Recursive with In-Band-SSM IPv4 P2MP Bindings
==============================================================================
No Matching Entries Found
==============================================================================
==============================================================================
LDP Recursive with In-Band-SSM IPv6 P2MP Bindings
==============================================================================
No Matching Entries Found
==============================================================================
==============================================================================
LDP VPN Recursive with Generic IPv4 P2MP Bindings
==============================================================================
No Matching Entries Found
==============================================================================
==============================================================================
LDP VPN Recursive with Generic IPv6 P2MP Bindings
==============================================================================
No Matching Entries Found
==============================================================================
==============================================================================
LDP GRT Recursive with Generic IPv4 P2MP Bindings
==============================================================================
No Matching Entries Found
==============================================================================
==============================================================================
LDP GRT Recursive with Generic IPv6 P2MP Bindings
==============================================================================
No Matching Entries Found
==============================================================================
===============================================================================
LDP Service FEC 128 Bindings
===============================================================================
Type               : ?-Eth               VcId                : 10
SvcId              : Ukwn                SdpId               : R. Src
Peer Address       : 1.1.1.1:0
Vc-switching       : No
LMTU               : None                RMTU                : 1500
Egr. Lbl           : 131070D             Egr. Ctl Word       : No
Egr. Flags         : None                Egr. Status Bits    : Supported (0x1e)
Egr. Flow Label Tx : No                  Egr. Flow Label Rx  : No
Egr. PW Status Sig : Enabled
Egr. Vccv CV Bits  : lsp-ping
Egr. Vccv CC Bits  : router-alert-label
Ing. Lbl           :  --                 Ing. Ctl Word       : None
Ing. Flags         : None                Ing. Status Bits    : N/A
Ing. Flow Label Tx : None                Ing. Flow Label Rx  : None
Ing. Wdraw Reason  : None
Ing. PW Status Sig : None
Ing. Vccv CV Bits  : None
Ing. Vccv CC Bits  : None
-------------------------------------------------------------------------------
===============================================================================
No. of VC Labels: 1
===============================================================================
===============================================================================
LDP Service FEC 129 Bindings
===============================================================================
No Matching Entries Found
===============================================================================
*A:Sar18 Dut-B>show>router>ldp#
ipv4
Syntax

ipv4 [session ip-addr[label-space]][summary | detail]

Context

show>router>ldp>bindings

Description

This command displays LDP active IPv4 bindings.

Parameters
ip-addr[label-space]

specifies the IP address and label space identifier

Values

ip-addr[label-spa* : ipv4-address:label-space

ipv6-address[label-space]

label-space : 0 to 65535]

detail

displays detailed information

summary

displays information in a summarized format

Output

The following outputs are examples of LDP active IPv4 bindings information, and LDP bindings field descriptions describes the fields.

Output example
*A:Sar18 Dut-B>show>router>ldp# bindings ipv4
===============================================================================
LDP Bindings (IPv4 LSR ID 10.10.10.10)
             (IPv6 LSR ID ::)
===============================================================================
Legend: U - Label In Use, N - Label Not In Use, W - Label Withdrawn
        S - Status Signaled Up,  D - Status Signaled Down
        E - Epipe Service, V - VPLS Service, M - Mirror Service
        A - Apipe Service, F - Fpipe Service, I - IES Service, R - VPRN service
        P - Ipipe Service, WP - Label Withdraw Pending, C - Cpipe Service
        BU - Alternate For Fast Re-Route, TLV - (Type, Length: Value), H -
 Hpipe Service
        LF - Lower FEC, UF - Upper FEC
===============================================================================
LDP IPv4 Prefix Bindings
===============================================================================
Prefix                                      IngLbl                    EgrLbl
Peer                                        EgrIntf/LspId
EgrNextHop
-------------------------------------------------------------------------------
10.10.10.10/32                                    --                      131071
10.10.10.10:0                                   1/1/1:100
10.1.1.1
10.12.12.12/32                                  131071U                     --
10.10.10.10:0                                     --
  --
-------------------------------------------------------------------------------
No. of IPv4 Prefix Bindings: 2
===============================================================================
===============================================================================
LDP Generic IPv4 P2MP Bindings
===============================================================================
P2MP-Id
RootAddr                                    Interface       IngLbl    EgrLbl
EgrNH                                       EgrIf/LspId
Peer
-------------------------------------------------------------------------------
No Matching Entries Found
===============================================================================
===============================================================================
LDP In-Band-SSM IPv4 P2MP Bindings
===============================================================================
Source
Group
RootAddr                                    Interface       IngLbl    EgrLbl
EgrNH                                       EgrIf/LspId
Peer
-------------------------------------------------------------------------------
No Matching Entries Found
===============================================================================
===============================================================================
LDP In-Band-VPN-SSM IPv4 P2MP Bindings
===============================================================================
Source
Group                                       RD
RootAddr                                    Interface       IngLbl    EgrLbl
EgrNH                                       EgrIf/LspId
Peer
-------------------------------------------------------------------------------
No Matching Entries Found
===============================================================================
===============================================================================
LDP Recursive with In-Band-SSM IPv4 P2MP Bindings
===============================================================================
RootAddr
InnerRootAddr
Source
Group                                       Interface       IngLbl    EgrLbl
EgrNH                                       EgrIf/LspId
Peer
-------------------------------------------------------------------------------
No Matching Entries Found
===============================================================================
===============================================================================
LDP VPN Recursive with Generic IPv4 P2MP Bindings
===============================================================================
P2MP-Id                                     RD
RootAddr                                    Interface
InnerRootAddr                                               IngLbl    EgrLbl
EgrNH                                       EgrIf/LspId
Peer
-------------------------------------------------------------------------------
No Matching Entries Found
===============================================================================
===============================================================================
LDP GRT Recursive with Generic IPv4 P2MP Bindings
===============================================================================
P2MP-Id
RootAddr                                    Interface       IngLbl    EgrLbl
InnerRootAddr
EgrNH                                       EgrIf/LspId
Peer
-------------------------------------------------------------------------------
No Matching Entries Found
===============================================================================
*A:Sar18 Dut-B>show>router>ldp#
*A:Sar18 Dut-B>show>router>ldp# bindings  ipv4 session 10.10.10.10:22 summary
 No. of IPv4 Prefix Bindings: 0
 No. of Generic IPv4 P2MP Bindings: 0
 No. of In-Band-SSM IPv4 P2MP Bindings: 0
 No. of In-Band-VPN-SSM IPv4 P2MP Bindings: 0
 No. of Recursive with In-Band-SSM IPv4 P2MP Bindings: 0
 No. of VPN Recursive with Generic IPv4 P2MP Bindings: 0
 No. of GRT Recursive with Generic IPv4 P2MP Bindings: 0
*A:Sar18 Dut-B>show>router>ldp#
*A:Sar18 Dut-B>show>router>ldp# bindings ipv4 detail
===============================================================================
LDP Bindings (IPv4 LSR ID 10.10.10.10)
             (IPv6 LSR ID ::)
===============================================================================
Legend: U - Label In Use, N - Label Not In Use, W - Label Withdrawn
        S - Status Signaled Up,  D - Status Signaled Down
        E - Epipe Service, V - VPLS Service, M - Mirror Service
        A - Apipe Service, F - Fpipe Service, I - IES Service, R - VPRN service
        P - Ipipe Service, WP - Label Withdraw Pending, C - Cpipe Service
        BU - Alternate For Fast Re-Route, TLV - (Type, Length: Value), H - Hpipe Se
rvice
        LF - Lower FEC, UF - Upper FEC
==============================================================================
LDP IPv4 Prefix Bindings
==============================================================================
-------------------------------------------------------------------------------
Prefix         : 10.10.10.10/32
-------------------------------------------------------------------------------
Peer           : 10.10.10.10:0
Ing Lbl        :   --               Egr Lbl    : 131071
Egr Int/LspId  : 10/10/10:100
EgrNextHop     : 10.1.1.1
Egr. Flags     : None               Ing. Flags : None
Egr If Name    : toA
Metric         : 1                  Mtu        : 1554
-------------------------------------------------------------------------------
Prefix         : 10.12.12.12/32
-------------------------------------------------------------------------------
Peer           : 10.10.10.1:0
Ing Lbl        : 131071U            Egr Lbl    :   --
Egr Int/LspId  :   --
EgrNextHop     :   --
Egr. Flags     : None               Ing. Flags : None
===============================================================================
No. of IPv4 Prefix Bindings: 2
==============================================================================
==============================================================================
LDP Generic IPv4 P2MP Bindings
==============================================================================
No Matching Entries Found
==============================================================================
==============================================================================
LDP In-Band-SSM IPv4 P2MP Bindings
==============================================================================
No Matching Entries Found
==============================================================================
==============================================================================
LDP In-Band-VPN-SSM IPv4 P2MP Bindings
==============================================================================
No Matching Entries Found
==============================================================================
==============================================================================
LDP Recursive with In-Band-SSM IPv4 P2MP Bindings
==============================================================================
No Matching Entries Found
==============================================================================
==============================================================================
LDP VPN Recursive with Generic IPv4 P2MP Bindings
==============================================================================
No Matching Entries Found
==============================================================================
==============================================================================
LDP GRT Recursive with Generic IPv4 P2MP Bindings
==============================================================================
No Matching Entries Found
==============================================================================
*A:Sar18 Dut-B>show>router>ldp#
ipv6
Syntax

ipv6 [session ip-addr[label-space]][summary | detail]

Context

show>router>ldp>bindings

Description

This command displays LDP active IPv6 bindings.

Parameters
ip-addr[label-space]

specifies the IP address and label space identifier

Values

ip-addr[label-spa* : ipv4-address:label-space

ipv6-address[label-space]

label-space : 0 to 65535]

detail

displays detailed information

summary

displays information in a summarized format

Output

The following output is an example of LDP active IPv6 bindings information, and LDP bindings field descriptions describes the fields.

Output example
*A:Sar18 Dut-B# show router ldp bindings ipv6 
===============================================================================
LDP Bindings (IPv4 LSR ID 10.12.12.12)
             (IPv6 LSR ID ::)
===============================================================================
Legend: U - Label In Use, N - Label Not In Use, W - Label Withdrawn
        S - Status Signaled Up,  D - Status Signaled Down
        E - Epipe Service, V - VPLS Service, M - Mirror Service
        A - Apipe Service, F - Fpipe Service, I - IES Service, R - VPRN service
        P - Ipipe Service, WP - Label Withdraw Pending, C - Cpipe Service
        BU - Alternate For Fast Re-Route, TLV - (Type, Length: Value), H -
 Hpipe Service
        LF - Lower FEC, UF - Upper FEC
===============================================================================
LDP IPv6 Prefix Bindings
===============================================================================
Prefix                                      IngLbl                    EgrLbl
Peer                                        EgrIntf/LspId
EgrNextHop
-------------------------------------------------------------------------------
No Matching Entries Found
===============================================================================
===============================================================================
LDP Generic IPv6 P2MP Bindings
===============================================================================
P2MP-Id
RootAddr                                    Interface       IngLbl    EgrLbl
EgrNH                                       EgrIf/LspId
Peer
-------------------------------------------------------------------------------
No Matching Entries Found
===============================================================================
===============================================================================
LDP In-Band-SSM IPv6 P2MP Bindings
===============================================================================
Source
Group
RootAddr                                    Interface       IngLbl    EgrLbl
EgrNH                                       EgrIf/LspId
Peer
-------------------------------------------------------------------------------
No Matching Entries Found
===============================================================================
===============================================================================
LDP In-Band-VPN-SSM IPv6 P2MP Bindings
===============================================================================
Source
Group                                       RD
RootAddr                                    Interface       IngLbl    EgrLbl
EgrNH                                       EgrIf/LspId
Peer
-------------------------------------------------------------------------------
No Matching Entries Found
===============================================================================
===============================================================================
LDP Recursive with In-Band-SSM IPv6 P2MP Bindings
===============================================================================
RootAddr
InnerRootAddr
Source
Group                                       Interface       IngLbl    EgrLbl
EgrNH                                       EgrIf/LspId
Peer
-------------------------------------------------------------------------------
No Matching Entries Found
===============================================================================
===============================================================================
LDP VPN Recursive with Generic IPv6 P2MP Bindings
===============================================================================
P2MP-Id                                     RD
RootAddr                                    Interface
InnerRootAddr                                               IngLbl    EgrLbl
EgrNH                                       EgrIf/LspId
Peer
-------------------------------------------------------------------------------
No Matching Entries Found
===============================================================================
===============================================================================
LDP GRT Recursive with Generic IPv6 P2MP Bindings
===============================================================================
P2MP-Id
RootAddr                                    Interface       IngLbl    EgrLbl
InnerRootAddr
EgrNH                                       EgrIf/LspId
Peer
-------------------------------------------------------------------------------
No Matching Entries Found
===============================================================================
*A:Sar18 Dut-B#
label-type
Syntax

label-type start-label start-label [end-label end-label] label-type [family]

Context

show>router>ldp>bindings

Description

This command displays LDP FEC bindings by matching labels.

Parameters
start-label

specifies a label value to begin the display

Values

16 to 1048575

end-label

specifies a label value to end the display

Values

17 to 1048575

label-type

specifies a label type to display

Values

ingress-label or egress-label

family

displays either IPv4 or IPv6 LDP information

Values

ipv4 or ipv6

Output

The following output is an example of LDP FEC bindings information by matching labels, and LDP bindings field descriptions describes the fields.

Output example
*A:Sar18 Dut-B>show>router>ldp# bindings label-type start-label 16 end-
label 99 ingress-label
===============================================================================
LDP Bindings (IPv4 LSR ID 10.12.12.12)
             (IPv6 LSR ID ::)
===============================================================================
Legend: U - Label In Use,  N - Label Not In Use, W - Label Withdrawn
        WP - Label Withdraw Pending, BU - Alternate For Fast Re-Route
        LF - Lower FEC, UF - Upper FEC
===============================================================================
LDP IPv4 Prefix Bindings
===============================================================================
Prefix                                      IngLbl                    EgrLbl
Peer                                        EgrIntf/LspId
EgrNextHop
-------------------------------------------------------------------------------
No Matching Entries Found
===============================================================================
===============================================================================
LDP IPv6 Prefix Bindings
===============================================================================
Prefix                                      IngLbl                    EgrLbl
Peer                                        EgrIntf/LspId
EgrNextHop
-------------------------------------------------------------------------------
No Matching Entries Found
===============================================================================
===============================================================================
LDP Service FEC 128 Bindings
===============================================================================
Type                                          VCId       SDPId     IngLbl  LMTU
Peer                                          SvcId                EgrLbl  RMTU
-------------------------------------------------------------------------------
No Matching Entries Found
===============================================================================
===============================================================================
LDP Service FEC 129 Bindings
===============================================================================
SAII                                            AGII        IngLbl    LMTU
TAII                                            Type        EgrLbl    RMTU
Peer                                            SvcId       SDPId
-------------------------------------------------------------------------------
No Matching Entries Found
===============================================================================
*A:Sar18 Dut-B>show>router>ldp#
p2mp
Syntax

p2mp p2mp-id identifier root ip-address [session ip-addr [label-space]] [summary | detail]

p2mp [session ip-addr [label-space]] [family] [summary | detail] [opaque-type opaque-type]

p2mp source ip-address group mcast-address root ip-address [session ip-addr [label-space]][family][summary | detail] inner-root ip-address

p2mp source ip-address group mcast-address root ip-address [rd rd] [session ip-addr [label-space]] [summary | detail]

p2mp source ip-address group mcast-address [session ip-addr [label-space]] [family] [summary | detail][innermost-root ip-address]

Context

show>router>ldp>bindings

Description

This command displays LDP P2MP FEC bindings.

Parameters
detail

displays detailed information

summary

displays information in a summarized format

family

displays either IPv4 or IPv6 active LDP information

group mcast-address

displays the P2MP group multicast address bindings

inner-root ip-address

displays recursive FECs whose inner root address matches the specified address

innermost-root ip-address

displays recursive FECs whose inner root address matches the specified address and non-recursive FECs that have a root address that matches the specified address

opaque-type opaque-type

specifies the type of a multipoint opaque value element

Values

generic, ssm, vpn-ssm, recursive-ssm, vpn-recursive, grt-recursive

p2mp-id identifier

displays LDP active P2MP identifier bindings

Values

0 to 4294967295

rd rd

displays information for the route distinguisher

Values

ip-addr:comm-val | 2byte-asnumber:ext-comm-val | 4byte-asnumber:comm-val

root ip-address

displays root IP address information

session ip-addr[label-space]

displays information for the LDP session IP address and label space

Values

ipv4-address:label-space

ipv6-address[label-space]

label-space: 0 to 65535

source ip-address

displays LDP active P2MP source bindings

Values

ipv4-address

a.b.c.d

ipv6-address

x:x:x:x:x:x:x:x (eight 16-bit pieces)

x:x:x:x:x:x:d.d.d.d

x - [0 to FFFF]H

d - [0 to 255]D

Output

The following output is an example of LDP P2MP FEC bindings information, and LDP bindings field descriptions describes the fields.

Output example
*A:7705:Dut-F# show router ldp bindings p2mp detail 
===============================================================================
LDP Bindings (IPv4 LSR ID 10.20.1.6)
             (IPv6 LSR ID ::)
===============================================================================
Legend: U - Label In Use,  N - Label Not In Use, W - Label Withdrawn
        WP - Label Withdraw Pending, BU - Alternate For Fast Re-Route
        LF - Lower FEC, UF - Upper FEC
==============================================================================
LDP Generic IPv4 P2MP Bindings
==============================================================================
-------------------------------------------------------------------------------
P2MP Type      : 1                  P2MP-Id    : 8193
Root-Addr      : 10.20.1.1
-------------------------------------------------------------------------------
Peer           : 10.20.1.4:0
Ing Lbl        : 131062U            
Egr Lbl        :   --               
Egr Int/LspId  :   --
EgrNextHop     :   --
Egr. Flags     : None               Ing. Flags : None
-------------------------------------------------------------------------------
P2MP Type      : 1                  P2MP-Id    : 8193
Root-Addr      : 10.20.1.1
-------------------------------------------------------------------------------
Peer           : 10.20.1.5:0
Ing Lbl        :   --               
Egr Lbl        : 131062             
Egr Int/LspId  : 1/1/3:0
EgrNextHop     : 10.180.10.5
Egr. Flags     : None               Ing. Flags : None
Egr If Name    : ip-10.180.10.6
Metric         : 1                  Mtu        : 1496
-------------------------------------------------------------------------------
P2MP Type      : 1                  P2MP-Id    : 8193
Root-Addr      : 10.20.1.2
-------------------------------------------------------------------------------
Peer           : 10.20.1.4:0
Ing Lbl        : 131064U            
Egr Lbl        :   --                 
Egr Int/LspId  :   --
EgrNextHop     :   --
Egr. Flags     : None               Ing. Flags : None
-------------------------------------------------------------------------------
P2MP Type      : 1                  P2MP-Id    : 8193
Root-Addr      : 10.20.1.2
-------------------------------------------------------------------------------
Peer           : 10.20.1.5:0
Ing Lbl        :   --               
Egr Lbl        : 131064             
Egr Int/LspId  : 1/1/3:0
EgrNextHop     : 10.180.10.5
Egr. Flags     : None               Ing. Flags : None
Egr If Name    : ip-10.180.10.6
Metric         : 1                  Mtu        : 1496
-------------------------------------------------------------------------------
P2MP Type      : 1                  P2MP-Id    : 8193
Root-Addr      : 10.20.1.3
-------------------------------------------------------------------------------
Peer           : 10.20.1.4:0
Ing Lbl        : 131063U            
Egr Lbl        :   --               
Egr Int/LspId  :   --
EgrNextHop     :   --
Egr. Flags     : None               Ing. Flags : None
-------------------------------------------------------------------------------
P2MP Type      : 1                  P2MP-Id    : 8193
Root-Addr      : 10.20.1.3
-------------------------------------------------------------------------------
Peer           : 10.20.1.5:0
Ing Lbl        :   --               
Egr Lbl        : 131063             
Egr Int/LspId  : 1/1/3:0
EgrNextHop     : 10.180.10.5
Egr. Flags     : None               Ing. Flags : None
Egr If Name    : ip-10.180.10.6
Metric         : 1                  Mtu        : 1496
-------------------------------------------------------------------------------
P2MP Type      : 1                  P2MP-Id    : 8193
Root-Addr      : 10.20.1.5            
-------------------------------------------------------------------------------
Peer           : 10.20.1.4:0
Ing Lbl        :   --               
Egr Lbl        : 131065             
Egr Int/LspId  : 1/1/1:0
EgrNextHop     : 10.180.9.4
Egr. Flags     : None               Ing. Flags : None
Egr If Name    : ip-10.180.9.6
Metric         : 1                  Mtu        : 1496
-------------------------------------------------------------------------------
P2MP Type      : 1                  P2MP-Id    : 8193
Root-Addr      : 10.20.1.5
-------------------------------------------------------------------------------
Peer           : 10.20.1.5:0
Ing Lbl        : 131065U            
Egr Lbl        :   --               
Egr Int/LspId  :   --
EgrNextHop     :   --
Egr. Flags     : None               Ing. Flags : None
-------------------------------------------------------------------------------
P2MP Type      : 1                  P2MP-Id    : 8193
Root-Addr      : 10.20.1.6
-------------------------------------------------------------------------------
Peer           : 10.20.1.4:0
Ing Lbl        :   --               
Egr Lbl        : 131061             
Egr Int/LspId  : 1/1/1:0
EgrNextHop     : 10.180.9.4
Egr. Flags     : None               Ing. Flags : None
Egr If Name    : ip-10.180.9.6
Metric         : 1                  Mtu        : 1496
-------------------------------------------------------------------------------
P2MP Type      : 1                  P2MP-Id    : 8193
Root-Addr      : 10.20.1.6
-------------------------------------------------------------------------------
Peer           : 10.20.1.5:0
Ing Lbl        :   --               
Egr Lbl        : 131061             
Egr Int/LspId  : 1/1/3:0
EgrNextHop     : 10.180.10.5          
Egr. Flags     : None               Ing. Flags : None
Egr If Name    : ip-10.180.10.6
Metric         : 1                  Mtu        : 1496
===============================================================================
No. of Generic IPv4 P2MP Bindings: 10
==============================================================================
==============================================================================
LDP Generic IPv6 P2MP Bindings
==============================================================================
No Matching Entries Found
==============================================================================
==============================================================================
LDP In-Band-SSM IPv4 P2MP Bindings
==============================================================================
No Matching Entries Found
==============================================================================
==============================================================================
LDP In-Band-SSM IPv6 P2MP Bindings
==============================================================================
No Matching Entries Found
==============================================================================
==============================================================================
LDP In-Band-VPN-SSM IPv4 P2MP Bindings
==============================================================================
No Matching Entries Found
==============================================================================
==============================================================================
LDP In-Band-VPN-SSM IPv6 P2MP Bindings
==============================================================================
No Matching Entries Found
==============================================================================
==============================================================================
LDP Recursive with In-Band-SSM IPv4 P2MP Bindings
==============================================================================
No Matching Entries Found
==============================================================================
==============================================================================
LDP Recursive with In-Band-SSM IPv6 P2MP Bindings
==============================================================================
No Matching Entries Found
==============================================================================
==============================================================================
LDP VPN Recursive with Generic IPv4 P2MP Bindings
==============================================================================
No Matching Entries Found
==============================================================================
==============================================================================
LDP VPN Recursive with Generic IPv6 P2MP Bindings
==============================================================================
No Matching Entries Found
==============================================================================
==============================================================================
LDP GRT Recursive with Generic IPv4 P2MP Bindings
==============================================================================
No Matching Entries Found
==============================================================================
==============================================================================
LDP GRT Recursive with Generic IPv6 P2MP Bindings
==============================================================================
No Matching Entries Found
==============================================================================
*A:7705:Dut-F# 
prefixes
Syntax

prefixes prefix ip-prefix/ip-prefix-length [summary | detail] [session ip-addr[label-space]]

prefixes [family] [summary | detail] [session ip-addr[label-space]]

Context

show>router>ldp>bindings

Description

This command displays LDP prefix FEC bindings.

Parameters
prefix ip-prefix/ip-prefix-length

specifies information for the specified IP prefix and mask length

Values

ipv4-prefix

a.b.c.d

ipv4-prefix-length

0 to 32

ipv6-address

x:x:x:x:x:x:x:x (eight 16-bit pieces)

x:x:x:x:x:x:d.d.d.d

x - [0 to FFFF]H

d - [0 to 255]D

ipv6-prefix-length

0 to 128

detail

displays detailed information

summary

displays information in a summarized format

family

displays either IPv4 or IPv6 active LDP information

Values

ipv4 or ipv6

session ip-addr

displays configuration information about LDP sessions

label-space

specifies the label space identifier that the router is advertising on the interface

Values

0 to 65535

Output

The following output is an example of LDP prefix FEC bindings information, and LDP bindings field descriptions describes the fields.

Output example
*A:Sar18 Dut-B>show>router>ldp# bindings prefixes
===============================================================================
LDP Bindings (IPv4 LSR ID 10.12.12.2)
             (IPv6 LSR ID ::)
===============================================================================
Legend: U - Label In Use,  N - Label Not In Use, W - Label Withdrawn
        WP - Label Withdraw Pending, BU - Alternate For Fast Re-Route
        LF - Lower FEC, UF - Upper FEC
===============================================================================
LDP IPv4 Prefix Bindings
===============================================================================
Prefix                                      IngLbl                    EgrLbl
Peer                                        EgrIntf/LspId
EgrNextHop
-------------------------------------------------------------------------------
10.10.10.1/32                                   --                      131071
1.1.1.1:0                                   1/1/1:100
10.1.1.1
10.12.12.12/32                              131071U                     --
10.1.1.1:0                                      --
  --
-------------------------------------------------------------------------------
No. of IPv4 Prefix Bindings: 2
===============================================================================
===============================================================================
LDP IPv6 Prefix Bindings
===============================================================================
Prefix                                      IngLbl                    EgrLbl
Peer                                        EgrIntf/LspId
EgrNextHop
-------------------------------------------------------------------------------
No Matching Entries Found
===============================================================================
*A:Sar18 Dut-B>show>router>ldp#
*A:Sar18 Dut-B>show>router>ldp# bindings prefixes detail
===============================================================================
LDP Bindings (IPv4 LSR ID 10.12.12.2)
             (IPv6 LSR ID ::)
===============================================================================
Legend: U - Label In Use,  N - Label Not In Use, W - Label Withdrawn
        WP - Label Withdraw Pending, BU - Alternate For Fast Re-Route
        LF - Lower FEC, UF - Upper FEC
==============================================================================
LDP IPv4 Prefix Bindings
==============================================================================
-------------------------------------------------------------------------------
Prefix         : 10.10.10.1/32
-------------------------------------------------------------------------------
Peer           : 10.10.10.1:0
Ing Lbl        :   --               Egr Lbl    : 131071
Egr Int/LspId  : 10/10/10:100
EgrNextHop     : 10.1.1.1
Egr. Flags     : None               Ing. Flags : None
Egr If Name    : toA
Metric         : 1                  Mtu        : 1554
-------------------------------------------------------------------------------
Prefix         : 10.12.12.2/32
-------------------------------------------------------------------------------
Peer           : 10.10.10.1:0
Ing Lbl        : 131071U            Egr Lbl    :   --
Egr Int/LspId  :   --
EgrNextHop     :   --
Egr. Flags     : None               Ing. Flags : None
===============================================================================
No. of IPv4 Prefix Bindings: 2
==============================================================================
==============================================================================
LDP IPv6 Prefix Bindings
==============================================================================
No Matching Entries Found
==============================================================================
*A:Sar18 Dut-B>show>router>ldp#
services
Syntax

services vc-type vc-type saii global-id:prefix:ac-id taii [256 chars max] agi agi [detail] [service-id service-id] [session ip-addr[label-space]]

services vc-type vc-type agi agi [detail] [service-id service-id] [session ip-addr[label-space]]

services [vc-type vc-type] [svc-fec-type] [detail] [service-id service-id] [session ip-addr[label-space]]

services vc-type vc-type vc-id vc-id [detail] [service-id service-id] [session ip-addr[label-space]]

Context

show>router>ldp>bindings

Description

This command displays LDP service FEC bindings.

Parameters
vc-type vc-type

displays information about the VC type associated with this service FEC

Values

ethernet, vlan, mirror, frdlci, atmsdu, atmcell, atmvcc, atmvpc, ipipe, satop-e1, satop-t1, cesopsn, cesopsn-cas

vc-id vc-id

displays information about the VC ID associated with this service FEC

Values

1 to 4294967295

saii global-id:prefix:ac-id

specifies the SAII (source attachment individual identifier)

Values

number:number | a.b.c.d:number

taii

specifies the TAII (target attachment individual identifier), up to 256 characters, associated with this service FEC

svc-fec-type

specifies the FEC type

Values

fec128, fec129

agi agi

specifies the attachment group identifier TLV associated with this service FEC

Values

ip-addr:comm-val | 2byte-asnumber:ext-comm-val | 4byte-asnumber:comm-val

ip-addr : a.b.c.d

comm-val : 0 to 65535

2byte-asnumber : 1 to 65535

ext-comm-val : 0 to 4294967295

4byte-asnumber : 1 to 4294967295

null - means all value is 0

detail

displays detailed information

service-id

specifies the service ID number to display

Values

1 to 2148007980 | svc-name (64 char max)

svc-fec-type

specifies the FEC type

Values

fec128, fec129

ip-addr[label-space]

specifies the IP address and the label space identifier that the router is advertising on the interface

Values

ipv4-address:label-space

ipv6-address[label-space]

label-space : 0 to 65535

Output

The following outputs are examples of LDP service FEC bindings information, and LDP bindings field descriptions describes the fields.

Output example
*A:Sar18 Dut-B>show>router>ldp# bindings services vc-type ethernet vc-id 999
===============================================================================
LDP Bindings (IPv4 LSR ID 10.2.2.2)
             (IPv6 LSR ID ::)
===============================================================================
Legend: U - Label In Use, N - Label Not In Use, W - Label Withdrawn
        S - Status Signaled Up,  D - Status Signaled Down
        E - Epipe Service, V - VPLS Service, M - Mirror Service
        A - Apipe Service, F - Fpipe Service, I - IES Service, R - VPRN service
        P - Ipipe Service, WP - Label Withdraw Pending, C - Cpipe Service
        BU - Alternate For Fast Re-Route, TLV - (Type, Length: Value), H -
 Hpipe Service
        LF - Lower FEC, UF - Upper FEC
===============================================================================
LDP Service FEC 128 Bindings
===============================================================================
Type                                          VCId       SDPId     IngLbl  LMTU
Peer                                          SvcId                EgrLbl  RMTU
-------------------------------------------------------------------------------
No Matching Entries Found
===============================================================================
*A:Sar18 Dut-B>show>router>ldp# bindings services vc-type ethernet vc- 
id 999 service-id 7777 
===============================================================================
LDP Bindings (IPv4 LSR ID 10.2.2.2)
             (IPv6 LSR ID ::)
===============================================================================
Legend: U - Label In Use, N - Label Not In Use, W - Label Withdrawn
        S - Status Signaled Up,  D - Status Signaled Down
        E - Epipe Service, V - VPLS Service, M - Mirror Service
        A - Apipe Service, F - Fpipe Service, I - IES Service, R - VPRN service
        P - Ipipe Service, WP - Label Withdraw Pending, C - Cpipe Service
        BU - Alternate For Fast Re-Route, TLV - (Type, Length: Value), H - 
         Hpipe Service
        LF - Lower FEC, UF - Upper FEC
===============================================================================
LDP Service FEC 128 Bindings
===============================================================================
Type                                          VCId       SDPId     IngLbl  LMTU
Peer                                          SvcId                EgrLbl  RMTU
-------------------------------------------------------------------------------
No Matching Entries Found
===============================================================================
*A:Sar18 Dut-B>show>router>ldp# bindings services vc-type ethernet vc-
id 999 service-id 7777 session 10.1.1.1:333
===============================================================================
LDP Bindings (IPv4 LSR ID 10.2.2.2)
             (IPv6 LSR ID ::)
===============================================================================
Legend: U - Label In Use, N - Label Not In Use, W - Label Withdrawn
        S - Status Signaled Up,  D - Status Signaled Down
        E - Epipe Service, V - VPLS Service, M - Mirror Service
        A - Apipe Service, F - Fpipe Service, I - IES Service, R - VPRN service
        P - Ipipe Service, WP - Label Withdraw Pending, C - Cpipe Service
        BU - Alternate For Fast Re-Route, TLV - (Type, Length: Value), H - 
         Hpipe Service
        LF - Lower FEC, UF - Upper FEC
===============================================================================
LDP Service FEC 128 Bindings
===============================================================================
Type                                          VCId       SDPId     IngLbl  LMTU
Peer                                          SvcId                EgrLbl  RMTU
-------------------------------------------------------------------------------
No Matching Entries Found
===============================================================================
*A:Sar18 Dut-B>show>router>ldp#
session
Syntax

session [family] [summary | detail] ip-addr[label-space]

Context

show>router>ldp>bindings

Description

This command displays LDP FEC bindings by matching peer LSR ID.

Parameters
detail

displays detailed information

summary

displays information in a summarized format

family

displays either IPv4 or IPv6 LDP session information

Values

ipv4 or ipv6

ip-addr[label-space]

specifies the IP address and the label space identifier that the router is advertising on the interface

Values

ipv4-address:label-space

ipv6-address[label-space]

label-space : 0 to 65535

Output

The following outputs are examples of LDP P2MP FEC bindings information by matching peer LSR ID, and LDP bindings field descriptions describes the fields.

Output example
*A:Dut-A# show router ldp bindings session 3ffe::a14:103 summary 
 No. of IPv4 Prefix Bindings: 0
 No. of IPv6 Prefix Bindings: 6
 No. of Generic IPv4 P2MP Bindings: 0
 No. of Generic IPv6 P2MP Bindings: 0
 No. of In-Band-SSM IPv4 P2MP Bindings: 0
 No. of In-Band-SSM IPv6 P2MP Bindings: 0
 No. of In-Band-VPN-SSM IPv4 P2MP Bindings: 0
 No. of In-Band-VPN-SSM IPv6 P2MP Bindings: 0
 No. of VC Labels: 0
 No. of FEC 129s: 0
*A:Dut-A# show router ldp bindings session 3ffe::a14:103 detail  
===============================================================================
LDP Bindings (IPv4 LSR ID 10.20.1.1:0)
             (IPv6 LSR ID 3ffe::a14:101[0])
===============================================================================
Legend: U - Label In Use, N - Label Not In Use, W - Label Withdrawn
        S - Status Signaled Up,  D - Status Signaled Down
        E - Epipe Service, V - VPLS Service, M - Mirror Service
        A - Apipe Service, F - Fpipe Service, I - IES Service, R - VPRN service
        P - Ipipe Service, WP - Label Withdraw Pending, C - Cpipe Service
        BU - Alternate For Fast Re-Route, TLV - (Type, Length: Value)
==============================================================================
LDP IPv4 Prefix Bindings
==============================================================================
No Matching Entries Found
==============================================================================
==============================================================================
LDP IPv6 Prefix Bindings
==============================================================================
-------------------------------------------------------------------------------
Prefix         : 3ffe::a14:101/128
-------------------------------------------------------------------------------
Peer           : 3ffe::a14:103[0]
Ing Lbl        : 262142U            Egr Lbl    :   --
Egr Int/LspId  :   --               
EgrNextHop     :   --
Egr. Flags     : None               Ing. Flags : None
-------------------------------------------------------------------------------
Prefix         : 3ffe::a14:102/128
-------------------------------------------------------------------------------
Peer           : 3ffe::a14:103[0]
Ing Lbl        : 262136U            Egr Lbl    : 262138
Egr Int/LspId  :   --               
EgrNextHop     :   --
Egr. Flags     : None               Ing. Flags : None
Egr If Name    : n/a                
-------------------------------------------------------------------------------
Prefix         : 3ffe::a14:103/128
-------------------------------------------------------------------------------
Peer           : 3ffe::a14:103[0]
Ing Lbl        :   --               Egr Lbl    : 262142
Egr Int/LspId  : 1/1/2              
EgrNextHop     : fe80::23
Egr. Flags     : None               Ing. Flags : None
Egr If Name    : ip-10.10.2.1       
Metric         : 1000               Mtu        : 1500
-------------------------------------------------------------------------------
Prefix         : 3ffe::a14:104/128
-------------------------------------------------------------------------------
Peer           : 3ffe::a14:103[0]
Ing Lbl        : 262132U            Egr Lbl    : 262134
Egr Int/LspId  :   --               
EgrNextHop     :   --
Egr. Flags     : None               Ing. Flags : None
Egr If Name    : n/a                
-------------------------------------------------------------------------------
Prefix         : 3ffe::a14:105/128
-------------------------------------------------------------------------------
Peer           : 3ffe::a14:103[0]
Ing Lbl        : 262134N            Egr Lbl    : 262132
Egr Int/LspId  : 1/1/2              
EgrNextHop     : fe80::23
Egr. Flags     : None               Ing. Flags : None
Egr If Name    : ip-10.10.2.1       
Metric         : 2000               Mtu        : 1500
-------------------------------------------------------------------------------
Prefix         : 3ffe::a14:106/128
-------------------------------------------------------------------------------
Peer           : 3ffe::a14:103[0]
Ing Lbl        : 262133U            Egr Lbl    : 262133
Egr Int/LspId  :   --               
EgrNextHop     :   --
Egr. Flags     : None               Ing. Flags : None
Egr If Name    : n/a                
===============================================================================
No. of IPv6 Prefix Bindings: 6
==============================================================================
==============================================================================
LDP Generic IPv4 P2MP Bindings
==============================================================================
No Matching Entries Found
==============================================================================
==============================================================================
LDP Generic IPv6 P2MP Bindings
==============================================================================
No Matching Entries Found
==============================================================================
==============================================================================
LDP In-Band-SSM IPv4 P2MP Bindings
==============================================================================
No Matching Entries Found
==============================================================================
==============================================================================
LDP In-Band-SSM IPv6 P2MP Bindings
==============================================================================
No Matching Entries Found
==============================================================================
==============================================================================
LDP In-Band-VPN-SSM IPv4 P2MP Bindings
==============================================================================
No Matching Entries Found
==============================================================================
==============================================================================
LDP In-Band-VPN-SSM IPv6 P2MP Bindings
==============================================================================
No Matching Entries Found
==============================================================================
===============================================================================
LDP Service FEC 128 Bindings
===============================================================================
No Matching Entries Found
===============================================================================
===============================================================================
LDP Service FEC 129 Bindings
===============================================================================
No Matching Entries Found
===============================================================================
*A:Dut-A# 
*A:Dut-A# show router ldp bindings session 10.20.1.3 ipv4 
===============================================================================
LDP Bindings (IPv4 LSR ID 10.20.1.1:0)
             (IPv6 LSR ID 3ffe::a14:101[0])
===============================================================================
Legend: U - Label In Use, N - Label Not In Use, W - Label Withdrawn
        S - Status Signaled Up,  D - Status Signaled Down
        E - Epipe Service, V - VPLS Service, M - Mirror Service
        A - Apipe Service, F - Fpipe Service, I - IES Service, R - VPRN service
        P - Ipipe Service, WP - Label Withdraw Pending, C - Cpipe Service
        BU - Alternate For Fast Re-Route, TLV - (Type, Length: Value)
===============================================================================
LDP IPv4 Prefix Bindings
===============================================================================
Prefix                                      IngLbl                    EgrLbl
Peer                                        EgrIntf/LspId             
EgrNextHop                                                            
-------------------------------------------------------------------------------
10.20.1.1/32                                262143U                     --
10.20.1.3:0                                   --                      
  --                                                                  
                                                                       
10.20.1.2/32                                262141U                   262140
10.20.1.3:0                                   --                      
  --                                                                  
                                                                       
10.20.1.3/32                                  --                      262143
10.20.1.3:0                                 1/1/2                     
10.10.2.3                                                             
                                                                       
10.20.1.4/32                                262139U                   262139
10.20.1.3:0                                   --                      
  --                                                                  
                                                                       
10.20.1.5/32                                262138N                   262137
10.20.1.3:0                                 1/1/2                     
10.10.2.3                                                             
                                                                       
10.20.1.6/32                                262135U                   262135
10.20.1.3:0                                   --                      
  --                                                                  
                                                                       
-------------------------------------------------------------------------------
No. of IPv4 Prefix Bindings: 6
===============================================================================
===============================================================================
LDP Generic IPv4 P2MP Bindings
===============================================================================
P2MP-Id                                                                
RootAddr                                    Interface       IngLbl    EgrLbl
EgrNH                                       EgrIf/LspId               
Peer                                                                  
-------------------------------------------------------------------------------
No Matching Entries Found
===============================================================================

===============================================================================
LDP In-Band-SSM IPv4 P2MP Bindings
===============================================================================
Source                                                                 
Group                                                                  
RootAddr                                    Interface       IngLbl    EgrLbl
EgrNH                                       EgrIf/LspId               
Peer                                                                  
-------------------------------------------------------------------------------
No Matching Entries Found
===============================================================================

===============================================================================
LDP In-Band-VPN-SSM IPv4 P2MP Bindings
===============================================================================
Source                                                                 
Group                                       RD                         
RootAddr                                    Interface       IngLbl    EgrLbl
EgrNH                                       EgrIf/LspId               
Peer                                                                  
-------------------------------------------------------------------------------
No Matching Entries Found
===============================================================================
*A:Dut-A# 
summary
Syntax

summary [session ip-addr[label-space]] [ipv4 | ipv6]

Context

show>router>ldp>bindings

Description

This command displays a summary of LDP bindings.

Parameters
session ip-addr[label-space]

specifies the IP address and label space identifier

Values

ip-addr[label-spa* : ipv4-address:label-space ipv6-address[label-space] label-space: 0 to 65535

ipv4

displays IPv4 summary bindings information

ipv6

displays IPv6 summary bindings information

Output

The following output is an example of summary LDP bindings information, and LDP bindings field descriptions describes the fields.

Output example
*A:Sar18 Dut-B>show>router>ldp# bindings summary
 No. of IPv4 Prefix Bindings: 2
 No. of IPv6 Prefix Bindings: 0
 No. of Generic IPv4 P2MP Bindings: 0
 No. of Generic IPv6 P2MP Bindings: 0
 No. of In-Band-SSM IPv4 P2MP Bindings: 0
 No. of In-Band-SSM IPv6 P2MP Bindings: 0
 No. of In-Band-VPN-SSM IPv4 P2MP Bindings: 0
 No. of In-Band-VPN-SSM IPv6 P2MP Bindings: 0
 No. of Recursive with In-Band-SSM IPv4 P2MP Bindings: 0
 No. of Recursive with In-Band-SSM IPv6 P2MP Bindings: 0
 No. of VPN Recursive with Generic IPv4 P2MP Bindings: 0
 No. of VPN Recursive with Generic IPv6 P2MP Binding: 0
 No. of GRT Recursive with Generic IPv4 P2MP Bindings: 0
 No. of GRT Recursive with Generic IPv6 P2MP Binding: 0
 No. of VC Labels: 1
 No. of FEC 129s: 0
*A:Sar18 Dut-B>show>router>ldp# bindings summary

Clear commands

fec-egress-statistics
Syntax

fec-egress-statistics [ip-prefix/mask]

Context

clear>router>ldp

Description

This command clears LDP FEC statistics.

Note: When LDP FEC statistics are cleared, the current aggregate statistics count is recorded as a baseline and is used to provide a relative count each time the statistics are viewed with the show command. Because this baseline number is not reconciled between the active and inactive CSMs, after a CSM activity switch the statistics on the newly active CSM shows the aggregate count as though no clear command has been executed.
Parameters
ip-prefix[/mask]

the IP prefix and prefix length associated with the prefix FEC

Values

ipv4-prefix:

a.b.c.d

ipv4-prefix-length:

32

ipv6-prefix:

x:x:x:x:x:x:x:x (eight 16-bit pieces)

x:x:x:x:x:x:d.d.d.d

x - [0 to FFFF]H

d - [0 to 255]D

ipv6-prefix-length:

128

instance
Syntax

instance

Context

clear>router>ldp

Description

This command resets the LDP instance.

interface
Syntax

interface ip-int-name[statistics]

Context

clear>router>ldp

Description

This command restarts or clears statistics for LDP interfaces.

Parameters
ip-int-name

specifies an existing interface. If the string contains special characters (such as #, $, spaces), the entire string must be enclosed within double quotes.

statistics

clears only the statistics for an interface

peer
Syntax

peer ip-address[statistics]

Context

clear>router>ldp

Description

This command restarts or clears statistics for LDP targeted peers.

Parameters
ip-address

specifies a targeted peer

statistics

clears only the statistics for a targeted peer

session
Syntax

session ip-addr [:label-space][statistics]

Context

clear>router>ldp

Description

This command restarts or clears statistics for LDP sessions.

Parameters
ip-addr

specifies the IP address of the LDP peer

label-space

specifies the label space identifier that the router is advertising on the interface

Values

0 to 65535

statistics

clears only the statistics for a session

statistics
Syntax

statistics

Context

clear>router>ldp

Description

This command clears LDP instance statistics.

Monitor commands

fec-egress-stats
Syntax

fec-egress-stats ip-prefix/mask[interval seconds][repeat repeat][absolute | rate]

Context

monitor>router>ldp

Description

This command displays egress statistics for LDP FEC prefixes at the configured interval until the configured count is reached.

Monitor commands are similar to show commands, but only statistical information is displayed. Monitor commands display the selected statistics according to the configured number of times at the interval specified.

Parameters
ip-prefix[/mask]

the IP prefix and prefix length associated with the prefix FEC

Values

ipv4-prefix:

a.b.c.d

ipv4-prefix-length:

32

ipv6-prefix:

x:x:x:x:x:x:x:x (eight 16-bit pieces)

x:x:x:x:x:x:d.d.d.d

x - [0 to FFFF]H

d - [0 to 255]D

ipv6-prefix-length:

128

seconds

specifies the interval for each display, in seconds

Values

3 to 60

Default

10

repeat

specifies how many times the command is repeated

Values

1 to 999

Default

10

absolute

displays raw statistics, without processing. No calculations are performed on the delta or rate statistics.

rate

displays the rate per second for each statistic instead of the delta

Output

The following output is an example of statistics for an LDP FEC instance.

===============================================================================
Monitor egress statistics for LDP FEC prefix 10.10.10.29/32
===============================================================================
-------------------------------------------------------------------------------
At time t = 0 sec (Base Statistics)
-------------------------------------------------------------------------------
-------------------------------------------------------------------------------
FEC Prefix/Mask    : 10.10.10.29/32
-------------------------------------------------------------------------------
Collect Stats      : Disabled             Accounting Plcy.     : None
Admin State        : Up                   
FC BE
InProf Pkts        : 0                    OutProf Pkts         : 0
InProf Octets      : 0                    OutProf Octets       : 0
FC L2
InProf Pkts        : 0                    OutProf Pkts         : 0
InProf Octets      : 0                    OutProf Octets       : 0
FC AF
InProf Pkts        : 0                    OutProf Pkts         : 0
InProf Octets      : 0                    OutProf Octets       : 0
FC L1
InProf Pkts        : 0                    OutProf Pkts         : 0
InProf Octets      : 0                    OutProf Octets       : 0
FC H2
InProf Pkts        : 0                    OutProf Pkts         : 0
InProf Octets      : 0                    OutProf Octets       : 0
FC EF
InProf Pkts        : 0                    OutProf Pkts         : 0
InProf Octets      : 0                    OutProf Octets       : 0
FC H1
InProf Pkts        : 0                    OutProf Pkts         : 0
InProf Octets      : 0                    OutProf Octets       : 0
FC NC
InProf Pkts        : 0                    OutProf Pkts         : 0
InProf Octets      : 0                    OutProf Octets       : 0
-------------------------------------------------------------------------------
At time t = 3 sec (Mode: Absolute)
-------------------------------------------------------------------------------
===============================================================================
Monitor egress statistics for LDP FEC prefix 10.10.10.29/32
===============================================================================
-------------------------------------------------------------------------------
At time t = 0 sec (Base Statistics)
-------------------------------------------------------------------------------
-------------------------------------------------------------------------------
FEC Prefix/Mask    : 10.10.10.29/32
-------------------------------------------------------------------------------
Collect Stats      : Disabled             Accounting Plcy.     : None
Admin State        : Up                   
FC BE
InProf Pkts        : 0                    OutProf Pkts         : 0
InProf Octets      : 0                    OutProf Octets       : 0
FC L2
InProf Pkts        : 0                    OutProf Pkts         : 0
InProf Octets      : 0                    OutProf Octets       : 0
FC AF
InProf Pkts        : 0                    OutProf Pkts         : 0
InProf Octets      : 0                    OutProf Octets       : 0
FC L1
InProf Pkts        : 0                    OutProf Pkts         : 0
InProf Octets      : 0                    OutProf Octets       : 0
FC H2
InProf Pkts        : 0                    OutProf Pkts         : 0
InProf Octets      : 0                    OutProf Octets       : 0
FC EF
InProf Pkts        : 0                    OutProf Pkts         : 0
InProf Octets      : 0                    OutProf Octets       : 0
FC H1
InProf Pkts        : 0                    OutProf Pkts         : 0
InProf Octets      : 0                    OutProf Octets       : 0
FC NC
InProf Pkts        : 0                    OutProf Pkts         : 0
InProf Octets      : 0                    OutProf Octets       : 0
-------------------------------------------------------------------------------
At time t = 3 sec (Mode: Rate)
-------------------------------------------------------------------------------
session
Syntax

sessionldp-id[ldp-id...(up to 5 max)][intervalseconds][repeatrepeat][absolute | rate]

Context

monitor>router>ldp

Description

This command displays statistical information for LDP sessions at the configured interval until the configured count is reached.

The first screen displays the current statistics related to the specified LDP sessions. The subsequent statistical information listed for each interval is displayed as a delta to the previous screen output.

When the keyword rate is specified, the rate per second for each statistic is displayed instead of the delta.

Monitor commands are similar to show commands, but only statistical information is displayed. Monitor commands display the selected statistics according to the configured number of times at the interval specified.

Parameters
ldp-id

specifies the IP address of the LDP session to display

Values

ip-addr[:label-space]

ip-addr — a.b.c.d

label-space — [0 to 65535]

seconds

configures the interval for each display in seconds

Values

3 to 60

Default

10

repeat

configures how many times the command is repeated

Values

1 to 999

Default

10

absolute

displays raw statistics, without processing. No calculations are performed on the delta or rate statistics.

rate

displays the rate per second for each statistic instead of the delta

Output

The following output is an example of statistical information for the LDP session.

ALU-103>monitor>router>ldp# session 10.10.10.104 interval 3 repeat 3 absolute
===============================================================================
Monitor statistics for LDP Session 10.10.10.104
===============================================================================
                              Sent                     Received
-------------------------------------------------------------------------------
At time t = 0 sec (Base Statistics)
-------------------------------------------------------------------------------
FECs                          1                        2
Hello                         5288                     5289
Keepalive                     8225                     8225
Init                          1                        1
Label Mapping                 1                        4
Label Request                 0                        0
Label Release                 0                        0
Label Withdraw                0                        0
Label Abort                   0                        0
Notification                  0                        0
Address                       1                        1
Address Withdraw              0                        0
-------------------------------------------------------------------------------
At time t = 3 sec (Mode: Absolute)
-------------------------------------------------------------------------------
FECs                          1                        2
Hello                         5288                     5289
Keepalive                     8226                     8226
Init                          1                        1
Label Mapping                 1                        4
Label Request                 0                        0
Label Release                 0                        0
Label Withdraw                0                        0
Label Abort                   0                        0
Notification                  0                        0
Address                       1                        1
Address Withdraw              0                        0
-------------------------------------------------------------------------------
At time t = 6 sec (Mode: Absolute)
-------------------------------------------------------------------------------
FECs                          1                        2
Hello                         5288                     5290
Keepalive                     8226                     8226
Init                          1                        1
Label Mapping                 1                        4
Label Request                 0                        0
Label Release                 0                        0
Label Withdraw                0                        0
Label Abort                   0                        0
Notification                  0                        0
Address                       1                        1
Address Withdraw              0                        0
-------------------------------------------------------------------------------
At time t = 9 sec (Mode: Absolute)
-------------------------------------------------------------------------------
FECs                          1                        2
Hello                         5288                     5290
Keepalive                     8226                     8226
Init                          1                        1
Label Mapping                 1                        4
Label Request                 0                        0
Label Release                 0                        0
Label Withdraw                0                        0
Label Abort                   0                        0
Notification                  0                        0
Address                       1                        1
Address Withdraw              0                        0
========================================================================
ALU-12>monitor>router>ldp#
ALU-12>monitor>router>ldp# session 10.10.10.104 interval 3 repeat 3 rate
===============================================================================
Monitor statistics for LDP Session 10.10.10.104
===============================================================================
                              Sent                     Received
-------------------------------------------------------------------------------
At time t = 0 sec (Base Statistics)
-------------------------------------------------------------------------------
FECs                          1                        2
Hello                         5289                     5290
Keepalive                     8227                     8227
Init                          1                        1
Label Mapping                 1                        4
Label Request                 0                        0
Label Release                 0                        0
Label Withdraw                0                        0
Label Abort                   0                        0
Notification                  0                        0
Address                       1                        1
Address Withdraw              0                        0
-------------------------------------------------------------------------------
At time t = 3 sec (Mode: Rate)
-------------------------------------------------------------------------------
FECs                          0                        0
Hello                         0                        0
Keepalive                     0                        0
Init                          0                        0
Label Mapping                 0                        0
Label Request                 0                        0
Label Release                 0                        0
Label Withdraw                0                        0
Label Abort                   0                        0
Notification                  0                        0
Address                       0                        0
Address Withdraw              0                        0
-------------------------------------------------------------------------------
At time t = 6 sec (Mode: Rate)
-------------------------------------------------------------------------------
FECs                          0                        0
Hello                         0                        0
Keepalive                     0                        0
Init                          0                        0
Label Mapping                 0                        0
Label Request                 0                        0
Label Release                 0                        0
Label Withdraw                0                        0
Label Abort                   0                        0
Notification                  0                        0
Address                       0                        0
Address Withdraw              0                        0
-------------------------------------------------------------------------------
At time t = 9 sec (Mode: Rate)
-------------------------------------------------------------------------------
FECs                          0                        0
Hello                         0                        0
Keepalive                     0                        0
Init                          0                        0
Label Mapping                 0                        0
Label Request                 0                        0
Label Release                 0                        0
Label Withdraw                0                        0
Label Abort                   0                        0
Notification                  0                        0
Address                       0                        0
Address Withdraw              0                        0
===============================================================================
ALU-12>monitor>router>ldp#
statistics
Syntax

statistics [interval seconds][repeat repeat][absolute | rate]

Context

monitor>router>ldp

Description

This command displays statistics for an LDP instance at the configured interval until the configured count is reached.

The first screen displays the current statistics related to the LDP statistics. The subsequent statistical information listed for each interval is displayed as a delta to the previous screen output.

When the keyword rate is specified, the rate per second for each statistic is displayed instead of the delta.

Monitor commands are similar to show commands, but only statistical information is displayed. Monitor commands display the selected statistics according to the configured number of times at the interval specified.

Parameters
seconds

configures the interval for each display in seconds

Values

3 to 60

Default

10

repeat

configures how many times the command is repeated

Values

1 to 999

Default

10

absolute

displays raw statistics, without processing. No calculations are performed on the delta or rate statistics.

rate

displays the rate per second for each statistic instead of the delta

Output

The following outputs are examples of statistics for an LDP instance.

ALU-12>monitor>router>ldp# statistics interval 3 repeat 3 absolute
===============================================================================
Monitor statistics for LDP instance
===============================================================================
At time t = 0 sec (Base Statistics)
-------------------------------------------------------------------------------
Addr FECs Sent    : 0                    Addr FECs Recv     : 0
Serv FECs Sent    : 1                    Serv FECs Recv     : 2
...
-------------------------------------------------------------------------------
At time t = 3 sec (Mode: Absolute)
-------------------------------------------------------------------------------
Addr FECs Sent    : 0                    Addr FECs Recv     : 0
Serv FECs Sent    : 1                    Serv FECs Recv     : 2
...
-------------------------------------------------------------------------------
At time t = 6 sec (Mode: Absolute)
-------------------------------------------------------------------------------
Addr FECs Sent    : 0                    Addr FECs Recv     : 0
Serv FECs Sent    : 1                    Serv FECs Recv     : 2
...
-------------------------------------------------------------------------------
At time t = 9 sec (Mode: Absolute)
-------------------------------------------------------------------------------
Addr FECs Sent    : 0                    Addr FECs Recv     : 0
Serv FECs Sent    : 1                    Serv FECs Recv     : 2
...
===============================================================================
ALU-12>monitor>router>ldp#
ALU-12>monitor>router>ldp# statistics interval 3 repeat 3 rate
===============================================================================
Monitor statistics for LDP instance
===============================================================================
At time t = 0 sec (Base Statistics)
-------------------------------------------------------------------------------
Addr FECs Sent    : 0                    Addr FECs Recv     : 0
Serv FECs Sent    : 1                    Serv FECs Recv     : 2
...
-------------------------------------------------------------------------------
At time t = 3 sec (Mode: Rate)
-------------------------------------------------------------------------------
Addr FECs Sent    : 0                    Addr FECs Recv     : 0
Serv FECs Sent    : 0                    Serv FECs Recv     : 0
...
-------------------------------------------------------------------------------
At time t = 6 sec (Mode: Rate)
-------------------------------------------------------------------------------
Addr FECs Sent    : 0                    Addr FECs Recv     : 0
Serv FECs Sent    : 0                    Serv FECs Recv     : 0
...
-------------------------------------------------------------------------------
At time t = 9 sec (Mode: Rate)
-------------------------------------------------------------------------------
Addr FECs Sent    : 0                    Addr FECs Recv     : 0
Serv FECs Sent    : 0                    Serv FECs Recv     : 0
...
===============================================================================

Debug commands

The following output shows debug LDP configurations discussed in this section.

ALU-12# debug router ldp peer 10.10.10.104
ALU-12>debug>router>ldp# show debug ldp
debug
    router "Base"
        ldp peer 10.10.10.104
            event
                bindings
                messages
            exit
            packet
                hello
                init
                keepalive
                label
            exit
        exit
    exit
exit
ALU-12>debug>router>ldp#
ldp
Syntax

[no] ldp

Context

debug>router

Description

This command configures LDP debugging.

interface
Syntax

[no] interface interface-name

Context

debug>router>ldp

Description

This command configures debugging for a specific LDP interface.

Parameters
interface-name

specifies an existing interface

peer
Syntax

[no] peer ip-address

Context

debug>router>ldp

Description

This command configures debugging for a specific LDP peer.

Parameters
ip-address

specifies the LDP peer to debug

event
Syntax

[no] event

Context

debug>router>ldp>interface

debug>router>ldp>peer

Description

This command configures debugging for specific LDP events.

bindings
Syntax

[no] bindings

Context

debug>router>ldp>peer>event

Description

This command displays debugging information about addresses and label bindings learned from LDP peers for LDP bindings.

The no form of the command disables the debugging output.

messages
Syntax

[no] messages

Context

debug>router>ldp>if>event

debug>router>ldp>peer>event

Description

This command displays specific information (for example, message type, source, and destination) about LDP messages sent to and received from LDP peers.

The no form of the command disables debugging output for LDP messages.

packet
Syntax

[no] packet

Context

debug>router>ldp>interface

debug>router>ldp>peer

Description

This command enables debugging for specific LDP packets.

The no form of the command disables the debugging output.

hello
Syntax

hello [detail]

no hello

Context

debug>router>ldp>if>packet

debug>router>ldp>peer>packet

Description

This command enables debugging for sent and received LDP Hello packets.

The no form of the command disables the debugging output.

Parameters
detail

displays detailed information

init
Syntax

init [detail]

no init

Context

debug>router>ldp>peer>packet

Description

This command enables debugging for LDP Init packets. The detail option displays detailed information about the type length value (TLV) included in mac-flush packets.

The no form of the command disables the debugging output.

Parameters
detail

displays detailed information

keepalive
Syntax

[no] keepalive

Context

debug>router>ldp>peer>packet

Description

This command enables debugging for LDP keepalive packets.

The no form of the command disables the debugging output.

label
Syntax

label [detail]

no label

Context

debug>router>ldp neighbor>packet

Description

This command enables debugging for LDP label packets.

The no form of the command disables the debugging output.

Parameters
detail

displays detailed information