BGP
This chapter provides information about configuring BGP.
BGP is supported on all 7210 SAS platforms as described in this document, except those operating in access-uplink mode.
BGP overview
Border Gateway Protocol (BGP) is an inter-autonomous system routing protocol. An autonomous system (AS) is a network or group of routers logically organized and controlled by a common network administration. BGP enables routers to exchange network reachability information, including information about other ASs that traffic must traverse to reach other routers in other ASs. To implement BGP, the ASN must be specified in the config>router context. A 7210 SAS BGP configuration must contain at least one group and include information about at least one 7210 SAS neighbor (peer).
AS paths are the routes to each destination. Other attributes, such as the origin of the path, the multiple exit discriminator (MED), the local preference, and communities included with the route are called path attributes. When BGP interprets routing and topology information, loops can be detected and eliminated. Route preference for routes learned from the configured peers can be enabled among groups of routes to enforce administrative preferences and routing policy decisions.
MP-BGP (family IPv4 and IPv6) for use in Layer 3 VPN services (also known as VPRN services) is supported on all platforms as described in this document.
BGP (family IPv4 and IPv6) is not available for use in the base routing instance. It is only available for use as a PE-CE routing protocol.
The VPN-IPv4, VPN-IPv6, and L2-VPN (BGP-AD) BGP address families are supported on the 7210 SAS-Mxp (standalone), 7210 SAS-Sx/S 1/10GE (standalone and standalone-VC), 7210 SAS-Sx 10/100GE (standalone and standalone-VC), and 7210 SAS-T (network).
The MVPN-IPv4 BGP address family is supported on the 7210 SAS-Mxp, 7210 SAS-R6, 7210 SAS-R12, 7210 SAS-Sx/S 1/10GE (standalone and standalone-VC), and 7210 SAS-T (network).
The EVPN BGP address family is supported only on the 7210 SAS-Mxp (standalone), 7210 SAS-R6, and 7210 SAS-R12.
BGP communication
There are two types of BGP peers: internal BGP (iBGP) and external BGP (eBGP) (BGP configuration):
iBGP is used to communicate with peers in the same autonomous system. Routes received from an iBGP peer in the same autonomous system are not advertised to other iBGP peers (unless the router is a route reflector) but can be advertised to an eBGP peer.
eBGP is used to communicate with peers in different autonomous systems. Routes received from an router in a different AS can be advertised to both eBGP and iBGP peers.
Autonomous systems share routing information, such as routes to each destination and information about the route or AS path, with other ASs using BGP. Routing tables contain lists of known routers, reachable addresses, and associated path cost metrics to each router. BGP uses the information and path attributes to compile a network topology.
Message types
Four message types are used by BGP to negotiate parameters, exchange routing information and indicate errors. They are:
Open message
After a transport protocol connection is established, the first message sent by each side is an Open message. If the Open message is acceptable, a Keepalive message confirming the Open is sent back. When the Open is confirmed, Update, Keepalive, and Notification messages can be exchanged.
Open messages consist of the BGP header and the following fields:
version
The current BGP version number is 4.
local ASN
The autonomous system number is configured in the config>router context.
hold time
Configure the maximum time BGP will wait between successive messages (either keep alive or update) from its peer, before closing the connection. Configure the local hold time with in the config>router>bgp context.
BGP identifier
IP address of the BGP system or the router ID. The router ID must be a valid host address.
Update message
Update messages are used to transfer routing information between BGP peers. The information contained in the packet can be used to construct a graph describing the relationships of the various autonomous systems. By applying rules, routing information loops and some other anomalies can be detected and removed from the inter-AS routing.
The update messages consist of a BGP header and the following optional fields:
unfeasible routes length
The field length which lists the routes being withdrawn from service because they are considered unreachable.
withdrawn routes
The associated IP address prefixes for the routes withdrawn from service.
total path attribute length
The total length of the path field that provides the attributes for a possible route to a destination.
path attributes
The path attributes presented in variable length TLV format.
network layer reachability information (NLRI)
IP address prefixes of reachability information.
keepalive Message
Keepalive messages, consisting of only a 19 octet message header, are exchanged between peers frequently so hold timers do not expire. The keepalive messages determine whether a link is unavailable.
notification
A Notification message is sent when an error condition is detected. The peering session is terminated and the BGP connection (TCP connection) is closed immediately after sending it.
The following figure shows BGP configuration.
Group configuration and peers
To enable BGP routing, participating routers must have BGP enabled and be assigned to an autonomous system and the neighbor (peer) relationships must be specified. A router typically belongs to only one AS. TCP connections must be established for neighbors to exchange routing information and updates. Neighbors exchange BGP open messages that includes information such as ASNs, BGP versions, router IDs, and hold-time values. Keepalive messages determine whether a connection is established and operational. The hold-time value specifies the maximum time BGP waits between successive messages (either keep alive or update) from its peer, before closing the connection.
In BGP, peers are arranged into groups. A group must contain at least one neighbor. A neighbor must belong to a group. Groups allow multiple peers to share similar configuration attributes.
Although neighbors do not have to belong to the same AS, they must be able to communicate with each other. If TCP connections are not established between two neighbors, the BGP peering is not established and updates are not exchanged.
Peer relationships are defined by configuring the IP address of the routers that are peers of the local BGP system. When neighbor and peer relationships are configured, the BGP peers exchange update messages to advertise network reachability information.
Hierarchical levels
BGP parameters are initially applied on the global level. These parameters are inherited by the group and neighbor (peer) levels. Parameters can be modified and overridden on a level-specific basis. BGP command hierarchy consists of three levels:
global level
group level
neighbor level
Many of the hierarchical BGP commands can be modified on different levels. The most specific value is used. That is, a BGP group-specific command takes precedence over a global BGP command. A neighbor-specific statement takes precedence over a global BGP and group-specific command; for example, if you modify a BGP neighbor-level command default, the new value takes precedence over group- and global- level settings.
Careful planning is essential to implement commands that can affect the behavior of global, group, and neighbor-levels. Because the BGP commands are hierarchical, analyze the values that can disable features on the global or group levels that must be enabled at the neighbor level. For example, if you enable the damping command on the global level but want it disabled only for a specific neighbor (not for all neighbors within the group), you cannot configure a double no command (no no damping) to enable the feature.
Route reflection
In a standard BGP configuration, all BGP speakers within an AS must have full BGP mesh to ensure that all externally learned routes are redistributed through the entire AS. iBGP speakers do not re-advertise routes learned from one iBGP peer to another iBGP peer. If a network grows, scaling issues could emerge because of the full mesh configuration requirement. Instead of peering with all other iBGP routers in the network, each iBGP router only peers with a router configured as a route reflector.
Route reflection circumvents the full mesh requirement but maintains the full distribution of external routing information within an AS. Route reflection is effective in large networks because it is manageable, scalable, and easy to implement. Route reflection is implemented in autonomous systems with a large internal BGP mesh to reduce the number of iBGP sessions required within an AS.
7210 SAS-R6 and 7210 SAS-R12 devices can be configured as route reflector clients or servers. These devices support route reflector server functionality for VPN-IPv4, VPN-IPv6, and BGP LU routes. All other 7210 SAS devices can be configured only as route reflector clients.
A route reflector (RR) provides route reflection services to iBGP peers called clients. Other iBGP peers of the RR are called non-clients. An RR and its client peers form a cluster. A large AS can be subdivided into multiple clusters, each identified by a unique 32-bit cluster ID. Each cluster contains at least one route reflector, which is responsible for redistributing route updates to all clients. Route reflector clients do not need to maintain a full peering mesh between each other. They only require peering to the route reflectors in their cluster. The route reflectors must maintain a full peering mesh between all non-clients within the AS.
Each route reflector must be assigned a cluster ID and specify which neighbors are clients and which are non-clients to determine which neighbors should receive reflected routes and which should be treated as a standard iBGP peer. Additional configuration is not required for the route reflector besides the typical BGP neighbor parameters.
The following figure shows a simple full-mesh configuration with several BGP routers. When SR-A receives a route from SR-1 (an external neighbor), it must advertise route information to all of its iBGP peers (SR-B, SR-C, SR-D, SR-E, SR-F). To prevent loops, iBGP learned routes are not re-advertised to other iBGP peers.
When route reflectors are configured, the routers within a cluster do not need to be fully meshed. The preceding figure shows a fully meshed network and BGP configuration with route reflectors shows the same network but with route reflectors configured to minimize the iBGP mesh between SR-A, SR-B, SR-C, and SR-D. SR-A, configured as the route reflector, is responsible for redistributing route updates to clients SR-B, SR-C, and SR-D. iBGP peering between SR-B, SR-C and SR-D is not necessary because even iBGP learned routes are reflected to the route reflector clients.
In the following figure, SR-E and SR-F are shown as non-clients of the route reflector. As a result, a full mesh of iBGP peerings must be maintained between SR-A, SR-E, and SR-F.
A route reflector enables communication between the clients and non-client peers. Clients of a route reflector do not need to be fully meshed but non-client peers need to be fully meshed within an AS.
A grouping (cluster) is composed of a route reflector (or a redundant pair of route reflectors configured with the same cluster ID) and its client peers. Each route reflector is assigned a cluster ID and this defines the cluster that it and its clients belong to. Multiple route reflectors can be configured within a cluster for redundancy. A router assumes the role as a route reflector by configuring the cluster cluster-id command. No other command is required unless the operator needs to disable reflection to specific clients.
When a route reflector receives an advertised route, it selects the best path. If the best path was received from an eBGP peer, then it is typically advertised, with next hop unchanged, to all clients and non-client peers of the route reflector. If the best path was received from a non-client peer, then it is advertised to all clients of the route reflector. If the best path was received from a client, then it is advertised to all clients and non-client peers.
A router becomes a route reflector whenever it has one or more client iBGP sessions. A client iBGP session is created with the cluster command, which also indicates the cluster ID of the client. The router ID is typically used as the cluster ID, but this is not necessary.
Basic route reflection operation (without add-path configured) can be summarized as follows:
If the best and valid path for an NLRI is learned from a client and disable-client-reflect is not configured, then that route is advertised to all clients, non-clients, and eBGP peers (as allowed by policy). If the client that advertised the best and valid path is a neighbor to which the split-horizon command (at the bgp, group, or neighbor level) applies, then the route is not advertised back to the sending client. In the route that is reflected to clients and non-clients:
The route reflector adds an ORIGINATOR_ID attribute if it does not already exist; the ORIGINATOR_ID indicates the BGP identifier (router ID) of the client that originated the route.
The route reflector prepends the cluster ID of the client that advertised the route and then the cluster ID of the client receiving the route (if applicable) to the CLUSTER_LIST attribute, creating the attribute if it does not already exist.
If the best and valid path for an NLRI is learned from a client and disable-client-reflect is configured, then that route is advertised to all clients in other clusters, non-clients, and eBGP peers (as allowed by policy). In the route that is reflected to clients in other clusters and non-clients:
The route reflector adds an ORIGINATOR_ID attribute if it does not already exist; the ORIGINATOR_ID indicates the BGP identifier (router ID) of the client that originated the route.
The route reflector prepends the cluster ID of the client that advertised the route and then the cluster ID of the client receiving the route (if applicable) to the CLUSTER_LIST attribute, creating the attribute if it does not already exist.
If the best and valid path for an NLRI is learned from a non-client, then that route is advertised to all clients and eBGP peers (as allowed by policy). In the route that is reflected to clients:
The route reflector adds an ORIGINATOR_ID attribute if it does not already exist; the ORIGINATOR_ID indicates the BGP identifier (router ID) of the non-client that originated the route.
The route reflector prepends the cluster ID of the client receiving the route to the CLUSTER_LIST attribute, creating the attribute if it already exists.
If the best and valid path for an NLRI is learned from an eBGP peer, then that route is advertised to all clients, non-clients, and other eBGP peers (as allowed by policy). The ORIGINATOR_ID and CLUSTER_LIST attributes are not added to the route.
If the best and valid path for an NLRI is locally originated by the RR — that is, it was learned through means other than BGP — then that route is advertised to all clients, non-clients, and eBGP peers (as allowed by policy). The ORIGINATOR_ID and CLUSTER_LIST attributes are not added to the route.
The ORIGINATOR_ID and CLUSTER_LIST attributes allow BGP to detect the looping of a route within the AS. If any router receives a BGP route with an ORIGINATOR_ID attribute containing its own BGP identifier, the route is considered invalid. In addition, if a route reflector receives a BGP route with a CLUSTER_LIST attribute containing a locally configured cluster ID, the route is considered invalid. Invalid routes are not installed in the route table and are not advertised to other BGP peers.
If VPN-IPv4 and VPN-IPv6 routes are advertised by a 7210 SAS router, the BGP next-hop address is set as follows for a reflected route:
When a route is reflected from one iBGP peer to another iBGP peer, the RR server does not modify the next hop by default; however, if the next-hop-self command is applied to the RR and enable-rr-vpn-forwarding is configured, then this combination of commands changes the next hop to the local address of the RR used with the peer.
If BGP 3107 LU service optimization has been configured using the config>router>bgp>group>neighbor>advertise-label ipv4 use-svc-routes command along with the enable-rr-vpn-forwarding command, only those BGP 3107 LU routes for which the node installs a swap entry for a VPN label are installed in the FIB.
On the 7210 SAS, the next-hop-self command can be used only in conjunction with the enable-rr-vpn-forwarding command or for BGP 3107 LU routes.
Fast external failover
Fast external failover on a group and neighbor basis is supported. For eBGP neighbors, this feature controls whether the router should drop an eBGP session immediately upon an interface-down event, or whether the BGP session should be kept up until the hold-time expires.
When fast external failover is disabled, the eBGP session stays up until the hold-time expires or the interface comes back up. If the BGP routes become unreachable as a result of the down IP interface, BGP withdraws the unavailable route immediately from other peers.
Sending of BGP communities
The capability to explicitly enable or disable the sending of the BGP community attribute to BGP neighbors, other than through the use of policy statements, is supported.
This feature allows an administrator to enable or disable the sending of BGP communities to an associated peer. This feature overrides communities that are already associated with a specific route or that may have been added via an export route policy. That is, even if the export policies leave BGP communities attached to a specific route, when the disable-communities feature is enabled, no BGP communities are advertised to the associated BGP peers.
ECMP and BGP route tunnels
ECMP is not supported for BGP route tunnels.
ECMP is not available for BGP route tunnels and also not on the transport LSP that is used to resolve BGP next-hop. If multiple LSP next-hops are available, only then the first next-hop is used and the rest ignored.
Next-hop resolution of BGP labeled routes to tunnels
The user enables the resolution of RFC 3107 BGP label route prefixes using tunnels to BGP next hops in the TTM with using following commands:
config>router>bgp>next-hop-res
labeled-route-transport-tunnel
[no] family family
resolution {any | disabled | filter}
resolution-filter
[no] ldp
[no] rsvp
[no] sr-isis
[no] sr-ospf
The 7210 SAS-Mxp does not support the use of RLFA with BGP 3107 labeled routes.
The transport-tunnel context allows the user to configure different types of BGP label routes: label-IPv4 and VPN routes (which includes both VPN-IPv4 and VPN-IPv6 routes). By default, all labeled routes resolve to LDP, even if the preceding CLI commands are not configured in the system.
If the resolution command is set to disabled, the default binding to LDP tunnels resumes. If resolution is set to any, the supported tunnel type selection is based on the TTM preference. The order of preference of TTM tunnels is the following:
RSVP
LDP
segment routing OSPF
segment routing IS-IS
If the rsvp option is enabled, BGP searches for the best metric RSVP LSP to the address of the BGP next-hop. The address can correspond to the system interface or to another loopback used by the BGP instance on the remote node. MPLS provides the LSP metric in the tunnel table. In the case of multiple RSVP LSPs with the same lowest metric, BGP selects the LSP with the lowest tunnel ID. When using RSVP LSP, only FRR one-to-one is supported for services using BGP 3107 labelled routes.
If the ldp option is enabled, BGP searches for an LDP LSP with a FEC prefix corresponding to the address of the BGP next-hop.
If the sr-isis or sr-ospf option is enabled, an SR tunnel to the BGP next-hop is selected in the TTM from the lowest preference IS-IS or OSPF instance. If many instances have the same lowest preference, the lowest numbered IS-IS or OSPF instance is chosen.
RLFA used with SR is not supported for BGP 3107 tunnels when services are resolved to use BGP 3107 tunnels.
resolution
command must be set to filter to
activate the list of tunnel types configured in the resolution-filter
context.VPN-IPv4 and VPN-IPv6 route resolution
The user enables the resolution of VPN-IPv4 and VPN-IPv6 prefixes using tunnels to MP-BGP peers using the following commands:
config>service>vprn
auto-bind-tunnel
resolution {any|disabled|filter}
resolution-filter
[no] ldp
[no] rsvp
[no] sr-isis
[no] sr-ospf
The auto-bind-tunnel context configures the binding of VPRN routes to tunnels. The user must configure the resolution command to enable auto-bind resolution to tunnels in the TTM. If the resolution command is set to disabled, auto-binding to a tunnel is removed.
If the resolution command is set to any, any supported tunnel type in the vprn context is selected following the TTM preference. If one or more explicit tunnel types are specified using the resolution-filter command, only these tunnel types are selected again following the TTM preference. The following tunnel types are supported in a vprn context in order of preference: RSVP, LDP, and segment routing (SR).
If the rsvp command is enabled, BGP searches for the best metric RSVP LSP to the address of the BGP next-hop. This address can correspond to the system interface or to another loopback that the BGP instance uses on the remote node. MPLS provides the LSP metric in the tunnel table. In the case of multiple RSVP LSPs with the same lowest metric, BGP selects the LSP with the lowest tunnel ID.
If the ldp command is enabled, BGP searches for an LDP LSP with a FEC prefix corresponding to the address of the BGP next-hop.
If the sr-isis or sr-ospf command is configured, an SR tunnel to the BGP next-hop is selected in the TTM from the lowest preference ISIS or OSPF instance. If many instances have the same lowest preference, the lowest numbered IS-IS or OSPF instance is chosen.
The BGP tunnel type is not explicitly configured in VPRN resolution and is therefore implicit. It is always preferred over any other tunnel type enabled in the auto-bind-tunnel context. However, the BGP tunnel type is configurable as a new tunnel type for BGP EVPN prefixes. The user must enable the BGP tunnel type to ensure that inter-area or inter-as prefixes are resolved.
The user must set the resolution command to filter to activate the list of tunnel types configured under resolution-filter.
When configured in a VPRN service (using the configure>service>vprn>spoke-sdp command), an explicit SDP to a BGP next-hop overrides the auto-bind-tunnel selection for that BGP next-hop only. There is no support for reverting automatically to the auto-bind-tunnel selection if the explicit SDP goes down. The user must delete the explicit spoke-SDP in the VPRN service to resume using the auto-bind-tunnel selection for the BGP next-hop.
Route selection criteria
For each prefix in the routing table, the routing protocol selects the best path. Then, the best path is compared to the next path in the list until all paths in the list are exhausted. The following criteria are used to determine the best path:
-
Routes are not considered if they are unreachable.
-
An RTM preference is lowered as well as the hierarchy of routes from a different protocol. The lower the preference the higher the chance of the route being the active route.
-
Routes with higher local preference have preference.
-
Routes with the shorter AS path have preference.
-
Routes with the lower origin have preference. IGP = 0 EGP = 1 INCOMPLETE = 2
-
Routes with the lowest MED metric have preference. Routes with no MED value are exempted from this step unless always-compare-med is configured.
-
Routes learned by an eBGP peer instead of those learned from an iBGP peer are preferred.
-
Routes with the lowest IGP cost to the next-hop path attribute are preferred.
-
Routes with the lowest BGP-ID are preferred.
-
Routes with shortest cluster list are preferred.
-
Routes with lowest next-hop IP address are preferred.
7210 SAS devices do not support BGP ECMP (multipath). An ECMP value is set to 1 and the following are assumed:
-
For BGP-VPN routes with the same prefix but a different Route Distinguisher (RD) that are imported in a VRF, if ECMP is not enabled in that VRF, the preceding selection criteria are used until parameter point 8. If all selection criteria are still the same after that point, the last updated route is selected.
-
For BGP-VPN routes with the same prefix but a different Route Distinguisher (RD) that reach parameter point 8 in the selection criteria, all routes are flagged as BEST and USED, although the actual number of used routes depends on the ECMP value configured in the VRF.
-
For BGP-VPN routes with the same prefix and same Route Distinguisher (RD) that reach parameter point 8 in the selection criteria, such routes are flagged as BEST, but parameter points 9 to 11 determine which routes are submitted to the VRF and marked as USED in accordance with the ECMP value configured in the VRF.
Enabling best external
Enabling the best-external feature is supported only at the config>router>bgp level. This feature can be enabled/disabled on a per address family basis, with IPv4 and IPv6 as the only options supported initially. Enabling best-external for IPv4 causes the new advertisement rules to apply to both regular IPv4 unicast routes as well as labeled-IPv4 (SAFI4) routes. Similarly, enabling best-external for IPv6 causes the new advertisement rules to apply to both regular IPv6 unicast routes as well as labeled-IPv6 (SAFI4) routes.
The advertise-external command cannot be applied to a route reflector unless client-to-client reflection is disabled (disable-client-reflect in the CLI).
BGP decision process with best external
When best-external is enabled for an address family, all routes belonging to that address family must be classified internally as either ‟internal” or ‟external”. A route is ‟internal” if:
It was received from an iBGP peer in the same AS.
It was originated by a router in the same or a different RR cluster of the same AS.
A route is ‟external” if it was received from an eBGP peer in a different AS.
The tie-breaking steps of the decision process are run as usual on all of the routes (both ‟internal” and ‟external”) for a particular destination until only one path, the best path, is left. If this is an external route then the decision process must be rerun on only the ‟internal” routes to find the single best path in that subset. This ‟best internal” route is advertised to confed-eBGP peers, as described in Advertisement rules with best external.
If the overall best path found by the first run of the decision process is an internal route with NEXT_HOP n the decision process must be rerun on only the ‟external” routes with NEXT_HOP not equal to n to find the single best path in that subset. This ‟best external” route is advertised to iBGP peers, as described in Advertisement rules with best external.
Advertisement rules with best external
The advertisement rules when advertise-external is enabled can be summarized as follows:
If a router has advertise-external enabled and its best overall route is an internal route then this best route should be advertised to:
all iBGP RR clients (if the route came from a non-client peer) or all iBGP non-clients (if the route came from a client peer).
all eBGP peers
If there is a best external route, it should be sent to iBGP client and non-client peers instead of the best overall route.
If a router has advertise-external enabled and its best overall route is an external route then this best route should be advertised to all iBGP peers and all eBGP peers.
Displaying best-external routes
BGP show commands display the following information for this feature:
For each RIB-IN entry in the output of the show router bgp routes prefix hunt command there is a Flags field that indicates the origin of the route and whether it is valid, best, used, and so on. This feature reflects an ‟Advertised” value in the Flags field. This indicates that the route was advertised to one or more peers. If the ‟Advertised” flag is present but the ‟Best” flag is not the operator can determine that the route was probably a best-external.
The show router bgp neighbor advertised-routes command displays all advertised routes to that peer, including routes that were overall best, best-external and best-internal.
The advertise-external configuration (specifically the address families for which it is enabled) is displayed as part of the show router bgp output.
Note that the overall best, best-external, and best-internal routes for a prefix can be determined from the output of the show router bgp routes prefix command. The first external route to be displayed in the output is always be the best-external route and the first internal route to be displayed in the output is always be the best-internal route. Only one of these routes will have the ‟Best” flag set, and this will be the overall best route.
BGP path attributes
A BGP route for a specific NLRI is distinguished from other BGP routes for the same NLRI by its set of path attributes. Each path attribute is encoded as a TLV in the Path Attributes field of the Update message, and describes a property of the path. The type field of the TLV identifies the path attribute and the value field carries data specific to the attribute type.
The 7210 SAS supports the following path attributes:
ORIGIN (well-known mandatory)
AS_PATH (well-known mandatory)
NEXT_HOP (well-known; required only in Update messages with IPv4 prefixes in the NLRI field); see Next-hop indirection for information about the NEXT_HOP attribute
MED (optional non-transitive)
LOCAL_PREF (well-known; required only in Update messages sent to iBGP peers)
ATOMIC_AGGR (well-known discretionary)
AGGREGATOR (optional transitive)
COMMUNITY (optional transitive)
ORIGINATOR_ID (optional non-transitive)
CLUSTER_LIST (optional non-transitive)
MP_REACH_NLRI (optional non-transitive)
MP_UNREACH_NLRI (optional non-transitive)
EXT_COMMUNITY (optional transitive)
AS4_PATH (optional transitive)
AS4_AGGREGATOR (optional transitive)
CONNECTOR (optional transitive)
PMSI_TUNNEL (supported only on platforms that support NG-MVPN with BGP signaling; see the 7210 SAS Software Release Notes 24.x.Rx for more information about NG-MVPN with BGP signaling)
NEXT_HOP attribute
The NEXT_HOP attribute indicates the IPv4 address of the BGP router that is the next hop to reach the IPv4 prefixes in the NLRI field. If the Update message is advertising routes other than IPv4 unicast routes, next hop of these routes is encoded in the MP_REACH_NLRI attribute and the NEXT_HOP attribute is not included in the Update message.
Next-hop indirection
The 7210 SAS supports next-hop indirection for most types of BGP routes. Next-hop indirection means that BGP next hops are logically separated from resolved next hops in the forwarding plane (IOMs). The separation allows the grouping of routes that share the same BGP next hops such that if the method of BGP next-hop resolution changes, only one forwarding plane update is required, instead of one update for each route in the group. The convergence time after the next-hop resolution change is uniform, and not linear, with the number of prefixes. The next-hop indirection technology supports Prefix-Independent Convergence (PIC). The 7210 SAS uses next-hop indirection whenever possible; there is no option to disable the functionality.
The following families support next-hop indirection on the 7210 SAS:
label-IPv4
MVPN-IPv4 (not supported on the 7210 SAS-Sx/S 1/10GE and 7210 SAS-Sx 10/100GE)
VPN-IPv4
label-IPv6
VPN-IPv6
L2-VPN
PW route
BGP Routing Information Base
The entire set of BGP routes learned and advertised by a BGP router make up its BGP Routing Information Base (RIB). Conceptually, the BGP RIB contains three parts:
RIB-IN
LOC-RIB
RIB-OUT
The RIB-IN (or Adj-RIBs-In, as defined in RFC 4271) contains the BGP routes received from peers that the router has stored in its memory.
The LOC-RIB contains modified versions of the BGP routes in the RIB-IN. The path attributes of a RIB-IN route can be modified using BGP import policies. All LOC-RIB routes for the NLRI are compared using the BGP decision process, which selects the best path for each NLRI. The local router uses the best paths in the LOC-RIB for forwarding, filtering, auto-discovery, and other tasks.
The RIB-OUT (or Adj-RIBs-Out, as defined in RFC 4271) contains the BGP routes selected for advertisement to peers. A BGP route is generally not advertised to a peer; that is, the router is not held in the RIB-OUT unless it is used locally, but there are exceptions. BGP export policies modify the path attributes of a LOC-RIB route to create the path attributes of the RIB-OUT route. A specific LOC-RIB route can be advertised with different path attribute values to different peers, and a 1:N relationship may exist between LOC-RIB and RIB-OUT routes.
When a VPN route is rejected by an import policy or not imported by any services, it is deleted from the RIB-IN. For VPN-IPv4 and VPN-IPv6 routes, this behavior can be changed by configuring the mp-bgp-keep command. Configuring this option maintains rejected VPN-IP routes in the RIB-IN and issuing a Route Refresh message is not required for an import policy change.
LOC-RIB features
The 7210 SAS implements the following LOC-RIB processing features:
BGP decision process
BGP route installation in the route table
BGP route installation in the tunnel table
BGP fast reroute
route flap damping (RFD)
The BGP fast reroute feature is described in BGP fast reroute and BGP fast reroute in a VPRN.
BGP fast reroute
BGP fast reroute uses indirection techniques in the forwarding plane and BGP backup path precomputation in the control plane to support the fast reroute of BGP traffic around unreachable or failed BGP next hops. BGP fast reroute is supported for label-IPv4, VPN-IPv4, and VPN-IPv6 routes. For information about BGP fast reroute in a VPRN, see BGP fast reroute in a VPRN.
The following table describes the scenarios supported in the base router BGP context.
Ingress packet |
Primary route |
Backup route |
PIC |
---|---|---|---|
IPv4 |
IPv4 route with next-hop A resolved by an IPv4 route or any shortcut tunnel |
IPv4 route with next-hop B resolved by an IPv4 route or any shortcut tunnel |
No |
IPv4 |
Label-IPv4 route with next-hop A resolved by any transport tunnel |
Label-IPv4 route with next-hop B resolved by any transport tunnel |
Yes |
IPv4 |
Label-IPv4 route with next-hop A resolved by a local route |
Label-IPv4 route with next-hop B resolved by a local route |
Yes |
IPv4 |
Label-IPv4 route with next-hop A resolved by a static route |
Label-IPv4 route with next-hop B resolved by a static route |
Yes |
Calculating backup paths
BGP fast reroute is optional on the 7210 SAS. Use the bgp backup-path command to enable the feature.
On the 7210 SAS, the backup-path command is supported only for label-IPv4 routes.
In the base router context, the backup-path command is used to control fast reroute on a per-RIB basis (labeled IPv4 routes). When the command specifies a particular family, BGP attempts to find a backup path for every prefix learned by the associated BGP RIB.
A prefix supports ECMP paths or a backup path, but not both. The backup path is the best path after the primary path and any paths using the same BGP next hop as the primary path have been removed.
Failure detection and switchover to the backup path
When BGP fast reroute is enabled, BGP decides when a primary path is no longer usable and notifies the IOM. Based on BGP input, the IOM immediately reroutes affected traffic to the backup path.
When BGP fast reroute is enabled, the IOM reroutes traffic onto a backup path based on input from BGP. When BGP decides that a primary path is no longer usable, it notifies the IOM and affected traffic is immediately switched to the backup path.
The following events trigger failure notifications to the IOM and traffic rerouting to backup paths:
peer IP address is unreachable and peer tracking is enabled
BFD session associated with the BGP peer goes down
BGP session is terminated with the peer (for example, send or receive NOTIFICATION)
there is no longer any route (allowed by the next-hop resolution policy, if configured) that can resolve the BGP next-hop address
BGP tunnel that resolves the next hop goes down because the BGP label-IPv4 route is withdrawn by the peer or becomes invalid because of an unresolved next hop
BGP fast reroute in a VPRN
In a VPRN context, BGP fast reroute is supported for VPN-IPv4 and VPN-IPv6 routes. On the 7210 SAS, BGP fast reroute is not supported for unlabeled IPv4 and unlabeled IPv6 routes.
The following table describes the supported VPRN scenarios.
Ingress packet |
Primary route |
Backup route |
PIC |
---|---|---|---|
IPv4 (ingress PE) |
IPv4 route with next-hop A resolved by an IPv4 route |
IPv4 route with next-hop B resolved by an IPv4 route |
No |
IPv4 (ingress PE) |
VPN-IPv4 route with next-hop A resolved by an LDP, RSVP, or BGP tunnel |
VPN-IPv4 route with next-hop A resolved by an LDP, RSVP, or BGP tunnel |
Yes |
MPLS (egress PE) |
IPv4 route with next-hop A resolved by an IPv4 route |
IPv4 route with next-hop B resolved by an IPv4 route |
No |
MPLS (egress PE) |
IPv4 route with next-hop A resolved by an IPv4 route |
VPN-IPv4 route with next-hop B resolved by an LDP, RSVP, or BGP tunnel |
No |
BGP fast reroute in a VPRN configuration
In a VPRN context, BGP fast reroute is optional and must be enabled. Fast reroute can be applied to all IPv4 prefixes, all IPv6 prefixes, all IPv4 and IPv6 prefixes, or to a specific set of IPv4 and IPv6 prefixes.
If all IP prefixes require backup path protection, use a combination of the BGP instance-level backup-path and VPRN-level enable-bgp-vpn-backup commands. The VPRN BGP backup-path command enables BGP fast reroute for all IPv4 prefixes and/or all IPv6 prefixes that have a best path through a VPRN BGP peer. The VPRN-level enable-bgp-vpn-backup command enables BGP fast reroute for all IPv4 prefixes and/or all IPv6 prefixes that have a best path through a remote PE peer.
RIB-OUT features
This section describes features related to RIB-OUT processing.
BGP export policies
The export command is used to apply one or more policies (up to 15) to a neighbor or group, or to the entire BGP context. The export command that is most specific to a peer is applied. An export policy command applied at the neighbor level takes precedence over the same command applied at the group or global level. An export policy command applied at the group level takes precedence over the same command specified on the global level. The export policies applied at different levels are not cumulative. The policies listed in an export command are evaluated in the order in which they are specified in the configuration.
The export command can reference a policy before the policy has been created as a policy-statement.
The most common uses for BGP export policies are the following:
BGP export policies can be used to locally originate a BGP route by exporting (or redistributing) a non-BGP route that is installed in the route table and actively used for forwarding. The non-BGP route is most frequently a direct, static, or aggregate route (exporting IGP routes into BGP is generally not recommended).
BGP export policies can be used to block the advertisement of specified BGP routes toward specific BGP peers. The routes may be blocked on the basis of IP prefix, communities, and so on.
BGP export policies can be used to modify the attributes of BGP routes advertised to specific BGP peers. The following path attribute modifications are possible using BGP export policies:
change the ORIGIN value
add a sequence of AS numbers to the start of the AS_PATH. When a route is advertised to an eBGP peer, the addition of the local-AS or global-AS numbers to the AS_PATH is always the final step (done after export policy).
replace the AS_PATH with a new AS_PATH. When a route is advertised to an eBGP peer, the addition of the local-AS or global-AS numbers to the AS_PATH is always the final step (done after export policy).
prepend an AS number multiple times to the start of the AS_PATH. When a route is advertised to an eBGP peer, the addition of the local-AS or global-AS numbers to the AS_PATH is always the final step (done after export policy). The add or replace action on the AS_PATH supersedes the prepend action if both are specified in the same policy entry.
change the NEXT_HOP to a specific IP address. When a route is advertised to an eBGP peer, the next hop cannot be changed from the local-address.
change the NEXT_HOP to the local-address used with the peer (next-hop-self)
add a value to the MED. If the MED attribute does not exist, it is added.
subtract a value from the MED. If the MED attribute does not exist, it is added with a value of 0. If the result of the subtraction is a negative number, the MED metric is set to 0.
set the MED to a specific value
set the MED to the cost of the IP route (or tunnel) used to resolve the BGP next hop
set LOCAL_PREF to a specific value when advertising to an iBGP peer
add, remove, or replace standard communities
add, remove, or replace extended communities
add a static value to the AIGP metric when advertising the route to an AIGP-enabled peer with a modified BGP next hop. The static value is incremental to the automatic adjustment of the LOC-RIB AIGP metric to reflect the distance between the local router and the received BGP next hop.
increment the AIGP metric by a fixed amount when advertising the route to an AIGP-enabled peer with a modified BGP next hop. The static value is a substitute for the dynamic value of the distance between the local router and the received BGP next hop.
Outbound Route Filtering
The ORF mechanism allows the ORF-sending router to signal to a peer, the ORF-receiving router, a set of route filtering rules (ORF entries) that the ORF-receiving router should apply to its route advertisements toward the ORF-sending router. The ORF entries are encoded in Route Refresh messages.
The use of ORF on a session must be negotiated; that is, both routers must advertise the ORF capability in their Open messages. The ORF capability describes the address families that support ORF, and for each address family, the ORF types that are supported and the ability to send and receive each type. 7210 SAS routers support ORF type 3, which is ORF based on extended communities, for only the following address families:
VPN-IPv4
VPN-IPv6
MVPN-IPv4
On the 7210 SAS, the send and receive capability for ORF type 3 is configurable using the send-orf and accept-orf commands, but the setting applies to all supported address families.
The 7210 SAS support for ORF type 3 allows a PE router that imports VPN routes with a particular set of route target extended communities to indicate to a peer (for example, a route reflector) that it only wants to receive VPN routes that contain one or more of these extended communities. When the PE router wants to inform its peer about a new RT extended community, it sends a Route Refresh message to the peer containing an ORF type 3 entry instructing the peer to add a permit entry for the 8-byte extended community value. When the PE router wants to inform its peer about an RT extended community that is no longer needed, it sends a Route Refresh message to the peer containing an ORF type 3 entry instructing the peer to remove the permit entry for the 8-byte extended community value.
On the 7210 SAS, the type-3 ORF entries that are sent to a peer can be generated dynamically (if no route target extended communities are specified with the send-orf command) or specified statically. Dynamically generated ORF entries are based on the route targets that are imported by all locally-configured VPRNs.
A router that has installed ORF entries received from a peer can still apply BGP export policies to the session. If the evaluation of a BGP export policy results in a reject action for a VPN route that matches a permit ORF entry, the route is not advertised; that is, the export policy has the final word.
The 7210 SAS implementation of ORF filtering is efficient. It takes less time to filter a large number of VPN routes with ORF than it does to reject non-matching VPN routes using a conventional BGP export policy.
Despite the advantages of ORF compared to manually configured BGP export policies, RTC is the better technology when it comes to dynamic filtering based on route target extended communities. See RT constrained route distribution for more information about RTC.
RT constrained route distribution
The RTC mechanism allows a router to advertise an RTC route, which is a special type of MP-BGP route, to specific peers; the associated AFI is 1 and the SAFI is 132. The NLRI of an RTC route encodes an origin AS and a route target extended community with prefix-type encoding (for example, if there is a prefix-length and host bits after the prefix-length are set to zero). A peer receiving RTC routes does not advertise VPN routes to the RTC-sending router unless they contain a route target extended community that matches one of the received RTC routes. As with any other type of BGP route, RTC routes are propagated loop-free throughout and between ASs. If multiple RTC routes exist for the same NLRI, the BGP decision process selects one as the best path. The propagation of the best path installs RIB-OUT filter rules as it travels from one router to the next, and this process creates an optimal VPN route distribution tree rooted at the source of the RTC route.
RTC and extended community-based ORF mechanisms are similar in that they both allow a router to signal to a peer the route target extended communities they want to receive in VPN routes from that peer. However, RTC has distinct advantages over extended community-based ORF because it is more widely supported, it is simpler to configure, and its distribution scope is not limited to a direct peer.
The capability to exchange RTC routes is advertised when the route-target keyword is added to the relevant family command. RTC is supported on eBGP and iBGP sessions of the base router instance. On a specific session, either ORF or RTC may be used, but not both; if RTC is configured, the ORF capability is not announced to the peer.
RTC is supported for the following BGP address families:
VPN-IPv4
VPN-IPv6
MVPN-IPv4
L2-VPN (BGP-AD)
EVPN
BGP address family support varies per 7210 SAS platform. RTC is supported only for the BGP families that the specific 7210 SAS platform supports. See BGP overview for more information.
When RTC is negotiated with one or more peers, the software automatically originates and advertises to these peers one /96 RTC route (the origin AS and route target extended community are fully specified) for every route target imported by a locally-configured VPRN or BGP-based Layer 2 VPN. Route targets are supported for all BGP families in the preceding list.
When route-target is enabled, it is activated for all address families configured on the node under BGP. Per-family activation is not supported.
The 7210 SAS also supports the group or neighbor level default-route-target command, which causes routers to generate and send a 0:0:0/0 default RTC route to one or more peers. Sending the default RTC route to a peer conveys a request to receive all VPN routes from that peer. The default-route-target command is typically configured on sessions that a route reflector has established with its PE clients. A received default RTC route is never propagated to other routers.
The route reflector advertises RTC routes in accordance with the rules described in RFC 4684. These rules ensure that RTC routes for the same NLRI that are originated by different PE routers in the same AS are correctly distributed within the AS.
When a BGP session comes up and RTC is enabled on the session (both peers advertised the MP-BGP capability), routers delay sending any VPN-IPv4 and VPN-IPv6 routes until either the session has been up for 60 seconds or the end-of-RIB marker is received for the RTC address family. When the VPN-IPv4 and VPN-IPv6 routes are sent, they are filtered to include only those with a route target extended community that matches an RTC route from the peer. VPN-IP routes matching an RTC route originated in the local AS are advertised to any iBGP peer that advertises a valid path for the RTC NLRI. That is, route distribution is not constrained to only the iBGP peer advertising the best path. However, VPN-IP routes matching an RTC route originated outside the local AS are only advertised to the eBGP or iBGP peer that advertises the best path.
The 7210 SAS does not support an equivalent of BGP-Multipath for RTC routes. There is no way to distribute VPN routes across more than one ‟almost” equal set of inter-AS paths.
Minimum Route Advertisement Interval
In accordance with RFC 4271, a BGP router should not send updated NLRI reachability information to a BGP peer until a specific period of time (the minimum route advertisement interval (MRAI)) has elapsed since the last update. The RFC suggests that the MRAI should be configurable per peer, but does not propose a specific algorithm; consequently, MRAI implementation details vary from one router operating system to another.
On the 7210 SAS, the MRAI is configurable on a per-session basis using the min-route-advertisement command. This CLI command can be configured with any value between 1 and 255 seconds, and the configuration applies to all address families. The default value is 30 seconds, regardless of the session type (eBGP or iBGP). The MRAI timer is started at the configured value when the session is established and counts down continuously. When the timer reaches zero, it resets to the configured value and all pending RIB-OUT routes are sent to the peer.
To send Update messages that advertise new NLRI reachability information more frequently for some address families than others, use the rapid-update command to overrides the remaining time on a peer MRAI timer and immediately send routes belonging to specified address families (and all other pending updates) to the peers receiving these routes. The following address families support rapid-update:
EVPN
L2-VPN
MVPN-IPv4
In many cases, the default MRAI is appropriate for all address families (or at least those not included in the preceding list) when it applies to Update messages that advertise reachable NLRI, but it is not the best option for Update messages that advertise unreachable NLRI (route withdrawals). Fast reconvergence after some types of failures requires route withdrawals to propagate to other routers as quickly as possible so that they can calculate and start using new best paths, which would be impeded by the effect of the MRAI timer at each router hop. This is facilitated by the rapid-withdrawal configuration command.
When rapid-withdrawal is configured, Update messages containing withdrawn NLRI are sent immediately to a peer without waiting for the MRAI timer to expire. Update messages containing reachable NLRI continue to wait for the MRAI timer to expire, or for a rapid-update trigger, if it applies. When rapid-withdrawal is enabled, it applies to all address families.
Advertise-inactive
BGP does not allow a route to be advertised unless it is the best path in the RIB and an export policy allows the advertisement.
In some cases, it may be useful to advertise the best BGP path to peers despite the fact that the BGP path is inactive, for example, if the path is inactive because there are one or more preferred non-BGP routes to the same destination and one of these other routes is the active route. The 7210 SAS supports this flexibility using the advertise-inactive command; other supported methods include Add-paths.
When the BGP advertise-inactive command is configured on a BGP session, it has the following effect on the IPv4, IPv6, label-IPv4, and label-IPv6 routes advertised to that peer:
If the active route for the IP prefix is a BGP route, that route is advertised.If the active route for the IP prefix is a non-BGP route and there is at least one valid but inactive BGP route for the same destination, the best of the inactive and valid BGP routes is advertised unless the non-BGP active route is matched and accepted by an export policy applied to the session.
If the active route for the IP prefix is a non-BGP route and there are no (valid) BGP routes for the same destination, no route is advertised for the prefix unless the non-BGP active route is matched and accepted by an export policy applied to the session.
Split-horizon
Split-horizon refers to the action taken by a router to avoid advertising a route back to the peer from which it was received. By default, the 7210 SAS applies split-horizon behavior only to routes received from iBGP non-client peers, and split-horizon only works for routes to non-imported routes within a RIB. Split-horizon functionality, which can never be disabled, prevents a route learned from a non-client iBGP peer from being advertised to the sending peer or any other non-client peer.
To apply split-horizon behavior to routes learned from RR clients or eBGP peers, configure the split-horizon command in either the global BGP, group or neighbor contexts. When split-horizon is enabled on these types of sessions, it only prevents the advertisement of a route back to its originating peer; for example, the software does not prevent the advertisement of a route learned from one eBGP peer back to a different eBGP peer in the same neighbor AS.
Add-paths
Receiving multiple paths per prefix from a BGP peer
If the 7210 SAS receives an advertisement of an NLRI and path from a specific peer and that peer subsequently advertises the same NLRI with different path information (a different next-hop or different path attributes), the new path overwrites the existing path.
However, when the add-path has been negotiated with the peer, the newly advertised path is stored in the RIB-IN along with all paths previously advertised (and not withdrawn) by the peer.
For router A to receive multiple paths per NLRI from peer B for a specific address family (AFI x, SAFI y), the BGP capabilities advertisement during session setup must indicate that peer B must send multiple paths for (AFI x, SAFI y) and router A is able to receive multiple paths for (AFI x, SAFI y).
When the add-path receive capability for (AFI x, SAFI y) has been negotiated with a peer, all advertisements and withdrawals of NLRI within that address family by that peer include a path identifier.
If the add-path has been negotiated with a peer and a path identifier is expected but missing, or if the add-path has not been negotiated with a peer and a path identifier is present but not expected, a Notification message is sent with the error subcode indicating Invalid Network Field, in accordance with standard BGP error handling procedures.
The path identifiers have no significance to the receiving peer. If the combination of NLRI and path identifier in an advertisement from a peer is unique (does not match an existing route in the RIB-IN from that peer), the route is added to the RIB-IN. If the combination of NLRI and path identifier in a received advertisement is the same as an existing route in the RIB-IN from the peer, the new route replaces the existing one. If the combination of NLRI and path identifier in a received withdrawal matches an existing route in the RIB-IN from the peer, that route is removed from the RIB-IN.
A BGP Update message from an add-path peer may advertise and withdraw more than one NLRI belonging to one or more address families. In this case, the add-path may be supported for some address families and not others. In this situation, the receiving BGP router should not require that all path identifiers in the Update message be the same.
The following figure shows an Update message carrying a VPN-IPv4 NLRI with a path identifier.
The following figure shows an Update message carrying an IPv4 NLRI with a path identifier.
Currently, add-path is only supported by the iBGP sessions with other add-path capable peers. The add-path capability is not supported for eBGP sessions or for native IPv4 and IPv6 routes (that is, IPv4 and IPv6 routes advertised without a label) in iBGP sessions.The ability to receive multiple paths per prefix from an add-path peer is configurable per route type. The supported route types are the following:
label-IPv4
label-IPv6
VPN-IPv4
VPN-IPv6
Path selection with add-paths
The LOC-RIB may have multiple paths for a prefix. The path selection mode refers to the algorithm used to decide which of these paths to advertise to an add-paths peer. SR OS supports the Add-N path selection algorithm described in draft-ietf-idr-add-paths-guidelines. The Add-N algorithm selects, as candidates for advertisement, the N best paths with unique BGP next-hops. In the SR OS implementation, the default value of N is configurable, per address-family, at the BGP instance, group and neighbor levels, however, this default value can be overridden, for specific prefixes, using route policies. The maximum number of paths to advertise for a prefix to an add-paths neighbor is the value N assigned by a BGP import policy to the best path for P, otherwise it defaults to the neighbor, group or instance level configuration of N for the address family to which P belongs.
Add-paths allows non-best paths to be advertised to a peer, but it still complies with basic BGP advertisement rules such as the iBGP split horizon rule: a route learned from an iBGP neighbor cannot be readvertised to another iBGP neighbor unless the router is configured as a route reflector.
BGP decision process with ADD-PATH
To use multiple paths per NLRI for forwarding and to advertise multiple paths per NLRI to add-path peers, a router implementing an add-path must run a modified version of the BGP decision process. The existing BGP decision algorithm selects the one best path for any particular NLRI. Paths that are second best or third best remain in the RIB-IN but are not installed in the LOC-RIB and not advertised to peers.
The system automatically changes its BGP decision process for routes belonging to a particular address family whenever either of the following applies:
BGP edge PIC is enabled for the address family
the add-path send capability is enabled for that address family on one or more peering sessions
When BGP PIC is enabled, the BGP decision process selects a backup path per prefix or NLRI to install in the LOC_RIB. The algorithm is summarized as follows:
Select the single best path based on a full evaluation of all the BGP tie-breaking rules, as described in the following examples:
Select the route with the highest route preference.
From all routes with an AIGP metric, select the route with the lowest sum of the AIGP metric value stored with the RIB-IN copy of the route and the iteratively resolved distance between the calculating router and the BGP NEXT_HOP of the route.
Select the route with the highest local preference (LOCAL_PREF).
Select the route with the shortest AS path.
Select the route with the lowest origin.
Among routes advertised by the same neighbor AS (unless always-compare-med is configured). Select the route with the lowest MED.
Prefer routes learned from eBGP peers over routes learned from iBGP peers.
Select the route with the lowest IGP cost (unless ignore-nh-metric is configured).
Select the route received by the peer with the lowest originator ID or BGP identifier.
Select the route with the shortest cluster list.
Select the route received from the lowest peer IP address.
Select up to one additional second best path among the paths remaining after removing from consideration all paths with a NEXT_HOP or BGP identifier (or originator ID) in common with any of the previously-selected best paths. A full evaluation of all the BGP tie-breaking rules is required to find this single second-best path, as shown in the following examples:
Select the route with the highest route preference.
Select the route with the highest local preference (LOCAL_PREF).
Select the route with the shortest AS path (unless as-path-ignore is configured).
Select the route with the lowest origin.
Among routes advertised by the same neighbor AS (unless always-compare-med is configured) select the route with the lowest MED.
Prefer routes learned from eBGP peers over routes learned from iBGP peers.
Select the route with the lowest IGP cost.
Select the route received by the peer with the lowest originator ID or BGP identifier.
Select the route with the shortest cluster list.
Select the route received from the lowest peer IP address.
Advertising multiple paths using ADD-PATH
For router A to send multiple paths per NLRI to peer B for a particular address family (AFI x, SAFI y), the BGP capability advertisement during session setup must indicate that router A must send multiple paths for (AFI x, SAFI y), and peer B is able to receive multiple paths for (AFI x, SAFI y).
By default, unless changed through configuration, all paths for a particular NLRI in the LOC-RIB are advertised to all add-path peers with which the send capability has been negotiated. All such advertisements (and any subsequent withdrawals) include a path identifier. Each advertised path for a specific NLRI must have a unique path identifier. When a path is reflected or propagated from one peer to another, the path identifier is expected to change, even if there has been no change in the next-hop. A BGP Update message sent to an add-path peer may advertise and withdraw more than one NLRI belonging to one or more address families. In this case, the add-path may be supported for some address families and not others, and the path identifiers associated with different NLRI in the Update message may be the same or different.
In the current implementation, the add-path is only supported by the iBGP sessions it forms with other add-path capable peers. The add-path capability is not supported for eBGP sessions or for native IPv4 and IPv6 routes (that is, IPv4 and IPv6 routes advertised without a label) in iBGP sessions. The ability to receive multiple paths per prefix from an add-path peer is configurable per route type. Route type support is as follows:
label-IPv4
label-IPv6
VPN-IPv4
VPN-IPv6
Limiting the number of paths per prefix
Advertising multiple paths per prefix to a peer means that the peer must maintain more entries in its RIB-IN than would be the case without add-path. The memory and CPU resources associated with these extra paths may not be justified if the peer cannot take advantage of them. Operators may therefore want precise control over the number of paths per prefix to send to particular peers.
The new add-paths CLI node (BGP, group or neighbor level) has address family-specific commands to set the maximum number of paths to send per prefix.
To ensure routing consistency in cases where an add-path speaking router has a mix of add-path and non add-path peers and where the number of paths to send for a particular prefix can vary by add-path peer, the following behavior should be enforced: if the advertising router advertises n paths for prefix XYZ to peer1 and m paths to peer2, and n < m, then all the paths advertised to peer1 must be included in the paths advertised to peer2. Suppose the LOC-RIB has N paths for prefix XYZ. The preceding behavior can be guaranteed if:
the N paths are sorted in strict order of their preference by the BGP decision process: p1 (overall best path found during step 1 of BGP decision process with ADD-PATH), p2, p3, …, pN (a path found during step 2 or 3 of BGP decision process with ADD-PATH)
p1 (only) is advertised to non add-path peers, add-path peers that indicate a send-only capability and add-path peers for which the configured path-limit is 1
(p1, p2) is advertised to add-path peers for which the configured path-limit is 2
(p1, p2, p3, …, pN) is advertised to add-path peers for which the configured path-limit is N, or else the path-limit is configured as max (default)
AIGP metric
Accumulated Interior Gateway Protocol (AIGP) is only supported on 7210 SAS-Mxp, 7210 SAS-R6, and 7210 SAS-R12.
The AIGP metric is an optional, non-transitive attribute that can be attached to selected routes using route policies. In networks that use AIGP, BGP paths with a lower end-to-end IGP cost are preferred, even if the compared paths span more than one AS or IGP instance. AIGP differs from MED in the following important ways:
AIGP is not transitive between completely distinct autonomous systems. It is only transitive across internal AS boundaries.
AIGP is always compared in paths that have the AIGP attribute, regardless of whether they are located in different neighbor ASs.
AIGP is more important than MED in the BGP decision process.
AIGP is automatically incremented every time there is a BGP next-hop change, so that the system can track the end-to-end IGP cost. All arithmetic operations on MED attributes must be performed manually, such as by using route policies.
On the 7210 SAS, AIGP is supported only in the base router BGP instance and only for label-IPv4 and 6PE routes. The AIGP attribute is only sent to peers configured using the aigp command. If the attribute is received from a peer that is not configured for AIGP, or if the attribute is received in a non-supported route type, the attribute is discarded and not propagated to other peers. The AIGP attribute is still displayed in BGP show command output.
When the 7210 SAS receives a route with an AIGP attribute and it re-advertises the route to an AIGP-enabled peer without changes to the BGP next hop, the AIGP metric value is unchanged by the advertisement (RIB-OUT) process. However, if the route is re-advertised with a new BGP next hop, the AIGP metric value is automatically incremented, either by the route table or tunnel table cost to reach the received BGP next hop, or by a value configured using route policies.
Command interactions and dependencies
This section describes the BGP command interactions and dependencies that apply to the configuration or operational maintenance of 7210 SAS routers.
Changing the ASN
If the autonomous system number (ASN) is changed on a router with an active BGP instance, the new ASN is not used until the BGP instance is restarted, either by administratively disabling or enabling the BGP instance or by rebooting the system with the new configuration.
BGP advertisement
BGP advertisement allows a BGP router to indicate to a peer, using the Optional Parameter, the features that it supports so that the router and peer can coordinate and use only the features that both support. Each capability in the Optional Parameter is TLV-encoded with a unique type code. The 7210 SAS supports the following capability codes:
Multiprotocol BGP (code 1)
Route refresh (code 2)
Outbound route filtering (code 3)
Graceful restart (code 64)
4-octet ASN (code 65)
Add-path (code 69)
Changing the local ASN
Changing the local AS of an active BGP instance:
at the global level, causes the BGP instance to restart with the new local ASN
at the group level, causes BGP to reestablish the peer relationships with all peers in the group with the new local ASN
at the neighbor level, causes BGP to reestablish the peer relationship with the new local ASN
Changing the router ID at the configuration level
If you configure a new router ID in the config>router context, protocols are not automatically restarted with the new router ID. The updated router ID is only used the next time the protocol is initialized or reinitialized. An interim period can occur when the protocols use different router IDs.
Hold time and keep alive timer dependencies
The BGP hold time specifies the maximum time BGP waits between successive messages (either keep alive or update) from its peer, before closing the connection. This configuration parameter can be set at three levels. The most specific value is used.
global level
This applies to all peers.
group level
This applies to all peers in group.
neighbor level
This applies only to a specified peer.
Although the keep alive time can be user specified, the configured keep alive timer is overridden by the value of hold time under the following circumstances:
If the hold time specified is less than the configured keep alive time, then the operational keep alive time is set to one third of the specified hold time; the configured keep alive time is unchanged.
If the hold time is set to zero, then the operational value of the keep alive time is set to zero; the configured keep alive time is unchanged. This means that the connection with the peer is up permanently and no keep alive packets are sent to the peer.
If the hold time or keep alive values are changed, the changed timer values take effect when the new peering relationship is established. Changing the values cause the peerings to restart. The changed timer values are used when renegotiating the peer relationship.
Import and export route policies
Import and export route policy statements are specified for BGP on the global, group, and neighbor level. Up to five unique policy statement names can be specified in the command line per level. The most specific command is applied to the peer. Defining the policy statement name is not required before being applied. Policy statements are evaluated in the order in which they are specified within the command context.
The import and export policies configured on different levels are not cumulative. The most specific value is used. An import or export policy command specified on the neighbor level takes precedence over the same command specified on the group or global level. An import or export policy command specified on the group level takes precedence over the same command specified on the global level.
Route damping and route policies
To prevent BGP systems from sending excessive route changes to peers, BGP route damping can be implemented. Damping can reduce the number of update messages sent between BGP peers, to reduce the load on peers, without adversely affecting the route convergence time for stable routes.
The damping profile defined in the policy statement is applied to control route damping parameters. Route damping characteristics are specified in a route damping profile and are referenced in the action for the policy statement or in the action for a policy entry. Damping can be specified at the global, group, or neighbor level with the most specific command applied to the peer.
AS Override
The BGP-4 Explicit AS Override simplifies the use of the same ASN across multiple RFC 2547 VPRN sites.
The Explicit AS Override feature can be used in VPRN scenarios where a customer is running BGP as the PE-CE protocol and some or all of the CE locations are in the same Autonomous System (AS). With normal BGP, two sites in the same AS would not be able to reach each other directly because there is an apparent loop in the ASPATH.
With AS Override enabled on an egress eBGP session, the Service Provider network can rewrite the customer ASN in the ASPATH with its own ASN as the route is advertised to the other sites within the same VPRN.
Configuration guidelines for BGP
The following are the configuration guidelines for BGP:
The 7210 SAS platforms can act only as a route reflector clients, except for the 7210 SAS-R6 and 7210 SAS-R12, which can act as route reflector servers.
The 7210 SAS platforms support IPv4 family for PE-CE eBGP instance and for RFC 3107 labeled IPv4 routes. It does not support the IPv4 family in the base routing instance to exchange IPv4 routes.
The 7210 SAS platforms support IPv6 family for PE-CE eBGP instance and for RFC 3107 labeled IPv6 routes. It does not support the IPv6 family in the base routing instance to exchange IPv6 routes.
BGP configuration process overview
The following figure shows the process to provision basic BGP parameters.
Configuration notes
This section describes BGP configuration restrictions.
General
Before BGP can be configured, the router ID (a valid host address, not the MAC address default) and autonomous system global parameters must be configured.
BGP instances must be explicitly created on each BGP peer. There are no default BGP instances on a 7210 SAS.
BGP defaults
The following list summarizes the BGP configuration defaults:
By default, the 7210 SAS is not assigned to an AS.
A BGP instance is created in the administratively enabled state.
A BGP group is created in the administratively enabled state.
A BGP neighbor is created in the administratively enabled state.
No BGP router ID is specified. If no BGP router ID is specified, BGP uses the router system interface address.
The 7210 SAS BGP timer defaults are the values recommended in IETF drafts and RFCs (see BGP MIB notes)
If no import route policy statements are specified, then all BGP routes are accepted.
If no export route policy statements specified, then all best and used BGP routes are advertised and non-BGP routes are not advertised.
BGP MIB notes
The 7210 SAS implementation of the RFC 1657 MIB variables listed in the following table differs from the IETF MIB specification.
MIB variable |
Description |
RFC 1657 allowed values |
Allowed values |
---|---|---|---|
bgpPeerMinASOriginationInterval |
Time interval in seconds for the MinASOriginationInterval timer. The suggested value for this timer is 15 seconds. |
1 to 65535 |
2 to 255 |
bgpPeerMinRouteAdvertisementInterval |
Time interval in seconds for the MinRouteAdvertisementInterval timer. The suggested value for this timer is 30. |
1 to 65535 |
1 to 255 1 |
If SNMP is used to set a value of X to the MIB variable in the following table, there are three possible results:
Condition |
Result |
---|---|
X is within IETF MIB values and X is within 7210 SAS values |
SNMP set operation does not return an error MIB variable set to X |
X is within IETF MIB values and X is outside 7210 SAS values |
SNMP set operation does not return an error MIB variable set to ‟nearest” 7210 SAS supported value (for example, 7210 SAS range is 2 to 255 and X = 65535, MIB variable is set to 255) Log message generated |
X is outside IETF MIB values and X is outside 7210 SAS values |
SNMP set operation returns an error |
When the value set using SNMP is within the IETF allowed values and outside the 7210 SAS values as specified in the preceding tables, a log message is generated. The log messages that display are similar to the following log messages:
Sample log message for setting bgpPeerMinASOriginationInterval to 65535
576 2006/11/12 19:45:48 [Snmpd] BGP-4-bgpVariableRangeViolation: Trying to set
bgpPeerMinASOrigInt to 65535 - valid range is [2-255] - setting to 255
Sample log message for setting bgpPeerMinASOriginationInterval to 1
594 2006/11/12 19:48:05 [Snmpd] BGP-4-bgpVariableRangeViolation: Trying to set
bgpPeerMinASOrigInt to 1 - valid range is [2-255] - setting to 2
Sample log message for setting bgpPeerMinRouteAdvertisementInterval to 256
535 2006/11/12 19:40:53 [Snmpd] BGP-4-bgpVariableRangeViolation: Trying to set
bgpPeerMinRouteAdvInt to 256 - valid range is [2-255] - setting to 255
Sample log message for setting bgpPeerMinRouteAdvertisementInterval to 1
566 2006/11/12 19:44:41 [Snmpd] BGP-4-bgpVariableRangeViolation: Trying to set
bgpPeerMinRouteAdvInt to 1 - valid range is [2-255] - setting to 2
Configuring BGP with CLI
This section provides information to configure BGP using the command line interface.
BGP configuration overview
Preconfiguration requirements
Before BGP can be implemented, the following entities must be configured:
the autonomous system (AS) number for the router
An ASN is a globally unique value which associates a router to a specific autonomous system. This number is used to exchange exterior routing information with neighboring ASs and as an identifier of the AS. Each router participating in BGP must have an ASN specified.
To implement BGP, the ASN must be specified in the config>router context.
router ID
The router ID is the IP address of the local router. The router ID identifies a packet origin. The router ID must be a valid host address.
BGP hierarchy
BGP is configured in the config>router>bgp context. Three hierarchical levels are included in BGP configurations:
global level
group level
neighbor level
Commands and parameters configured on the global level are inherited to the group and neighbor levels although parameters configured on the group and neighbor levels take precedence over global configurations.
Internal and external BGP configurations
A BGP system consists of ASs that share network reachability information. Network reachability information is shared with adjacent BGP systems neighbors. Further logical groupings are established within BGP systems within ASs. BGP supports two types of routing information exchanges:
External BGP (EBGP) is used between ASs
EBGP speakers peer to different ASs and typically share a subnet. In an external group, the next hop is dependent upon the interface shared between the external peer and the specific neighbor. The
multihop
command must be specified if an EBGP peer is more than one hop away from the local router. The next hop to the peer must be configured so that the two systems can establish a BGP session.Internal BGP (IBGP) is used within an AS
An IBGP speaker peers to the same AS and typically does not share a subnet. Neighbors do not have to be directly connected to each other. Because IBGP peers are not required to be directly connected, IBGP uses the IGP path (the IP next-hop learned from the IGP) to reach an IBGP peer for its peering connection.
Basic BGP configuration
This section provides information to configure BGP and configuration examples of common configuration tasks. The minimal BGP parameters that need to be configured are:
an autonomous system number for the router
a router ID
Note that if a new or different router ID value is entered in the BGP context, the new value takes precedence and overwrites the router-level router ID.
a BGP peer group
a BGP neighbor with which to peer
a BGP peer-AS that is associated with the preceding peer
The BGP configuration commands have three primary configuration levels: bgp for global configurations, group name for BGP group configuration, and neighbor ip-addressfor BGP neighbor configuration. Within the different levels, many of the configuration commands are repeated. For the repeated commands, the command that is most specific to the neighboring router is in effect, that is, neighbor settings have precedence over group settings which have precedence over BGP global settings.
The following is a sample configuration that includes the preceding parameters. The other parameters are optional.
info
#--------------------------------------------------
echo "IP Configuration"
#--------------------------------------------------
...
autonomous-system 200
router-id 10.10.10.103
#--------------------------------------------------
...
#--------------------------------------------------
echo "BGP Configuration"
#--------------------------------------------------
bgp
exit
cluster 0.0.0.100
export "direct2bgp"
router-id 10.0.0.12
group "To_AS_10000"
connect-retry 20
hold-time 90
keepalive 30
local-preference 100
remove-private
peer-as 10000
neighbor 10.0.0.8
description "To_Router B - EBGP Peer"
connect-retry 20
hold-time 90
keepalive 30
local-address 10.0.0.12
passive
preference 99
peer-as 10000
exit
exit
group "To_AS_30000"
connect-retry 20
hold-time 90
keepalive 30
local-preference 100
remove-private
peer-as 30000
neighbor 10.0.3.10
description "To_Router C - EBGP Peer"
connect-retry 20
hold-time 90
keepalive 30
peer-as 30000
exit
exit
group "To_AS_40000"
connect-retry 20
hold-time 30
keepalive 30
local-preference 100
peer-as 65206
neighbor 10.0.0.15
no bfd-enable
description "To_Router E - Sub Confederation AS 65205"
connect-retry 20
hold-time 90
keepalive 30
local-address 10.0.0.12
peer-as 65205
exit
exit
exit
#--------------------------------------------------
....
A:ALA-48>config>router#
Common configuration tasks
This section provides a brief overview of the tasks that must be performed to configure BGP and provides the CLI commands. To enable BGP, one AS must be configured and at least one group must be configured which includes neighbor (system or IP address) and peering information (ASN).
Configure BGP hierarchically, the global level (applies to all peers), the group level (applies to all peers in peer-group), or the neighbor level (only applies to specified peer). By default, group members inherit the group configuration parameters although a parameter can be modified on a per-member basis without affecting the group-level parameters.
Many of the hierarchical BGP commands can be used on different levels. The most specific value is used. That is, a BGP group-specific command takes precedence over a global BGP command. A neighbor-specific statement takes precedence over a global BGP or group-specific command.
All BGP instances must be explicitly created on each node. When created, BGP is administratively enabled.
Configuring a basic autonomous system
Configuration planning is essential to organize ASs and the 7210 SAS nodes within the ASs, and determine the internal and external BGP peering.
To configure a basic autonomous system, perform the following tasks:
-
Prepare a plan detailing the autonomous systems, the 7210 SAS node belonging to each group, group names, and peering connections.
-
Associate each 7210 SAS node with an autonomous system number.
-
Configure each 7210 SAS node with a router ID.
-
Associate each 7210 SAS node with a peer group name.
-
Specify the local IP address that will be used by the group or neighbor when communicating with BGP peers.
-
Specify neighbors.
-
Specify the autonomous system number associated with each neighbor.
Creating an autonomous system
Before BGP can be configured, the autonomous system must be configured first. In BGP, routing reachability information is exchanged between autonomous systems (ASs). An AS is a group of networks that share routing information. The autonomous-system command associates an autonomous system number to the router being configured. A 7210 SAS device can only belong to one AS. The autonomous-system command is configured in the config>router context.
Use the following syntax to associate a 7210 SAS device to an autonomous system.
config>router# autonomous-system autonomous-system
The 7210 SAS device supports 4 bytes ASNs by default. This means autonomous-system can have any value from 1 to 4294967295.
Autonomous system configuration command usage
config>router# autonomous-system 100
Autonomous system configuration output
ALA-B>config>router# info
#------------------------------------------
# IP Configuration
#------------------------------------------
interface "system"
address 10.10.10.104/32
exit
interface "to-103"
address 10.0.0.104/24
port 1/1/1
exit
autonomous-system 100
#------------------------------------------
ALA-B>config>router#
Configuring a router ID
In BGP, routing information is exchanged between autonomous systems. The BGP router ID, expressed like an IP address, uniquely identifies the router. It can be set to be the same as the loopback address.
Note that if a new or different router ID value is entered in the BGP context, then the new router ID value is used instead of the router ID configured on the router level, system interface level, or inherited from the MAC address. The router-level router ID value remains intact. A router ID can be derived by:
defining the value in the config>router router-id context
defining the system interface in the config>router>interface ip-int-name context
inheriting the last four bytes of the MAC address
the BGP protocol level (the router ID can be defined in the config>router>bgp router-id context and is only used within BGP)
When configuring a new router ID, protocols are not automatically restarted with the new router ID. The next time a protocol is (re) initialized the new router ID is used. An interim period of time can occur when different protocols use different router IDs. To force the new router ID, issue the shutdown and no shutdown commands for each protocol that uses the router ID or restart the entire router.
Use the following CLI syntax to configure the router ID:
config>router# router-id router-id
Command usage to configure a router ID
config>router# router-id 10.10.10.104
Router ID configuration output
ALA-B>config>router# info
----------------------------------------------
# IP Configuration
#------------------------------------------
interface "system"
address 10.10.10.104/32
exit
interface "to-103"
address 10.0.0.104/24
port 1/1/1
exit
autonomous-system 100
router-id 10.10.10.104
#------------------------------------------
...
ALA-B>config>router#
BGP components
The following section describes the syntax used to configure the BGP attributes.
Configuring BGP
When the BGP protocol instance is created, the no shutdown command is not required because BGP is administratively enabled upon creation. Minimally, to enable BGP on a router, you must associate an autonomous system number for the router, have a preconfigured router ID or system interface, create a peer group, neighbor, and associate a peer ASN. There are no default groups or neighbors. Each group and neighbor must be explicitly configured.
All parameters configured for BGP are applied to the group and are inherited by each peer, but a group parameter can be overridden on a specific basis. BGP command hierarchy consists of three levels:
the global level
the group level
the neighbor level
config>router# bgp (global level)
group (group level)
neighbor (neighbor level)
Careful planning is essential when implementing commands that can affect the behavior of global, group, and neighbor levels. Because the BGP commands are hierarchical, analyze the values that can disable features on a particular level.
Basic BGP configuration output
ALA-B>config>router# info
#------------------------------------------
# BGP Configuration
#------------------------------------------
#------------------------------------------
# BGP
#------------------------------------------
bgp
exit
#------------------------------------------
ALA-B>config>router#
Configuring group attributes
A group is a collection of related BGP peers. The group name should be a descriptive name for the group. Follow your group, name, and ID naming conventions for consistency and to help when troubleshooting faults.
All parameters configured for a peer group are applied to the group and are inherited by each peer (neighbor), but a group parameter can be overridden on a specific neighbor-level basis.
The following is a sample BGP group configuration output.
ALA-B>config>router>bgp# info
----------------------------------------------
...
group "headquarters1"
description "HQ execs"
local-address 10.0.0.104
disable-communities standard extended
ttl-security 255
exit
exit
...
----------------------------------------------
ALA-B>config>router>bgp#
Configuring neighbor attributes
After you create a group name and assign options, add neighbors within the same autonomous system to create IBGP connections and neighbors in different autonomous systems to create EBGP peers. All parameters configured for the peer group level are applied to each neighbor, but a group parameter can be overridden on a specific neighbor basis.
The following is a sample output for neighbors configured in group ‟headquarters1”.
ALA-B>config>router>bgp# info
----------------------------------------------
...
group "headquarters1"
description "HQ execs"
local-address 10.0.0.104
disable-communities standard extended
ttl-security 255
neighbor 10.0.0.5
passive
peer-as 300
exit
neighbor 10.0.0.106
peer-as 100
exit
neighbor 10.5.0.2
hold-time 90
keepalive 30
min-as-origination 15
local-preference 170
peer-as 10701
exit
neighbor 10.5.1.2
hold-time 90
keepalive 30
min-as-origination 15
local-preference 100
min-route-advertisement 30
preference 170
peer-as 10702
exit
exit
...
----------------------------------------------
ALA-B>config>router>bgp#
Configuring AIGP
AIGP is only supported on 7210 SAS-Mxp.
The AIGP metric is an optional, non-transitive attribute that can be attached to selected routes using route policies. In networks that use AIGP, BGP paths with a lower end-to-end IGP cost are preferred, even if the compared paths span more than one AS or IGP instance.
AIGP is supported only in the base router BGP instance and only for label-IPv4 and 6PE routes. The AIGP attribute is only sent to peers configured using the configure>router>bgp>group>aigp and configure>router>bgp>group>neighbor>aigp commands.
The following is a sample BGP policy configuration output with AIGP attribute information included.
*A:Dut-C>config>router>policy-options# info
----------------------------------------------
policy-statement "AIGP_ADD"
description "Policy From bgp To bgp"
entry 10
description "Entry 10 - From Prot. bgp To bgp"
from
protocol bgp
exit
to
protocol bgp
exit
action accept
aigp-metric add 555
exit
exit
exit
policy-statement "AIGP_EXPORT_PLCY"
description "Policy From bgp To bgp"
entry 10
description "Entry 10 - From Prot. bgp To bgp"
from
protocol bgp
exit
to
protocol bgp
exit
action accept
next-hop 10.20.1.3
exit
exit
exit
----------------------------------------------
The following is a sample BGP instance configuration output with AIGP attribute information included.
*A:Dut-C>config>router>bgp# info
----------------------------------------------
min-route-advertisement 1
router-id 10.20.1.3
group "PEER_TO_A"
neighbor 10.10.1.1
local-address 10.10.1.3
peer-as 200
advertise-label ipv4
exit
exit
group "PEER_RR_TO_D_E_B"
cluster 10.20.1.3
aigp
neighbor 10.20.1.2
local-address 10.20.1.3
med-out 100
import "AIGP_ADD"
peer-as 300
advertise-label ipv4
exit
neighbor 10.20.1.4
local-address 10.20.1.3
med-out 100
peer-as 300
advertise-label ipv4
exit
neighbor 10.20.1.5
local-address 10.20.1.3
export "AIGP_EXPORT_PLCY"
peer-as 300
advertise-label ipv4
exit
exit
no shutdown
----------------------------------------------
BGP configuration management tasks
This section describes the BGP configuration management tasks.
Modifying an ASN
You can modify an ASN on a 7210 SAS but the new ASN is not used until the BGP instance is restarted either by administratively disabling or enabling the BGP instance or by rebooting the system with the new configuration.
Because the ASN is defined in the config>router context, not in the BGP configuration context, the BGP instance is not aware of the change. Re-examine the plan detailing the autonomous systems, the SRs belonging to each group, group names, and peering connections. Changing an ASN on a 7210 SAS could cause configuration inconsistencies if associated peer-as values are not also modified as required. At the group and neighbor levels, BGP reestablishes the peer relationships with all peers in the group with the new ASN.
Use the following syntax to change an ASN.
config>router# autonomous-system autonomous-system
config>router# bgp
group name
neighbor ip-addr
peer-as asn
config>router# autonomous-system 400
config>router# bgp
config>router>bgp# group headquarters1
config>router>bgp>group# neighbor 10.10.10.103
config>router>bgp>group# peer-as 400
config>router>bgp>group# exit
Modifying the BGP router ID
Changing the router ID number in the BGP context causes the new value to overwrite the router ID configured on the router level, system interface level, or the value inherited from the MAC address. Changing the router ID on a router could cause configuration inconsistencies if associated values are not also modified.
When configuring a new router ID, protocols are not automatically restarted with the new router ID. The next time BGP is (re) initialized the new router ID is used. To force the new router ID, issue the shutdown and no shutdown commands for BGP or restart the entire router.
config>router>bgp# router-id 10.0.0.104
config>router>bgp# shutdown
config>router>bgp# router-id 10.0.0.123
config>router>bgp# no shutdown
This following is a sample BGP configuration with the BGP router ID specified.
ALA-B>config>router>bgp# info detail
----------------------------------------------
no shutdown
no description
no always-compare-med
ibgp-multipath load-balance
. . .
router-id 10.0.0.123
----------------------------------------------
ALA-B>config>router>bgp#
Modifying the router-level router ID
Changing the router ID number in the config>router context causes the new value to overwrite the router ID configured on the protocol level, system interface level, or the value inherited from the MAC address. Changing the router ID on a router could cause configuration inconsistencies if associated values are not also modified.
When configuring a new router ID, protocols are not automatically restarted with the new router ID. The next time a protocol is (re) initialized the new router ID is used. An interim period of time can occur when different protocols use different router IDs. To force the new router ID, issue the shutdown and no shutdown commands for each protocol that uses the router ID or restart the entire router.
Use the following syntax to change a router ID.
config>router# router-id router-id
config>router# router-id 10.10.10.104
config>router# no shutdown
config>router>bgp# shutdown
config>router>bgp# no shutdown
The following is a sample router ID configuration output.
ALA-A>config>router# info
#------------------------------------------
# IP Configuration
#------------------------------------------
interface "system"
address 10.10.10.104/32
exit
interface "to-103"
address 10.0.0.104/24
port 1/1/1
exit
autonomous-system 100
router-id 10.10.10.104
#------------------------------------------
ALA-B>config>router#
Deleting a neighbor
To delete a neighbor, you must shut down the neighbor before issuing the no neighbor ip-addr command.
Use the following syntax to delete a neighbor.
config>router# bgp
group name
no neighbor ip-address
shutdown
no peer-as asn
shutdown
config>router# bgp
config>router>bgp# group headquarters1
config>router>bgp>group# neighbor 10.0.0.103
config>router>bgp>group>neighbor# shutdown
config>router>bgp>group>neighbor# exit
config>router>bgp>group# no neighbor 10.0.0.103
The following is a sample ‟headquarters1
”
configuration output with the neighbor 10.0.0.103
removed.
ALA-B>config>router>bgp# info
----------------------------------------------
group "headquarters1"
description ‟HQ execs”
local-address 10.0.0.104
neighbor 10.0.0.5
passive
peer-as 300
exit
exit
----------------------------------------------
ALA-B>config>router>bgp#
Deleting groups
To delete a group, the neighbor configurations must first be shut down. After each neighbor shuts down, you must shut down the group before issuing the no group namecommand.
Use the following syntax to shut down a peer and neighbor and then delete a group.
config>router# bgp
no group name
shutdown
no neighbor ip-address
shutdown
shutdown
config>router# bgp
config>router>bgp# group headquarters1
config>router>bgp>group# neighbor 10.0.0.105
config>router>bgp>group>neighbor# shutdown
config>router>bgp>group>neighbor# exit
config>router>bgp>group# neighbor 10.0.0.103
config>router>bgp>group# shutdown
config>router>bgp>group# exit
config>router>bgp# no headquarters1
Trying to delete the group without shutting it down results in the following message:
ALA-B>config>router>bgp# no group headquarters1
MINOR: CLI BGP Peer Group should be shutdown before deleted. BGP Peer Group not
deleted.
Editing BGP parameters
Use the following syntax to change existing BGP parameters. The changes are applied immediately.
config>router# bgp
group name
. . .
neighbor ip-address
. . .
config>router# bgp
See BGP components for a complete list of BGP parameters.
BGP command reference
Command hierarchies
Configuration commands
Global BGP commands
config
- router [router-name]
- [no] bgp
- [no] add-paths
- ipv4 send send-limit
- ipv4 send send-limit receive [none]
- no ipv4
- ipv6 send send-limit
- ipv6 send send-limit receive [none]
- no ipv6
- vpn-ipv4 send send-limit
- vpn-ipv4 send send-limit receive [none]
- no vpn-ipv4
- vpn-ipv6 send send-limit
- vpn-ipv6 send send-limit receive [none]
- no vpn-ipv6
- [no] advertise-inactive
- [no] aggregator-id-zero
- authentication-key [authentication-key | hash-key] [hash | hash2]
- no authentication-key
- auth-keychain name
- [no] backup-path [ipv4]
- best-path-selection
- always-compare-med {zero | infinity}
- always-compare-med strict-as {zero | infinity}
- no always-compare-med
- as-path-ignore [ipv4] [vpn-ipv4]
- no as-path-ignore
- ignore-nh-metric
- no ignore-nh-metric
- ignore-router-id
- no ignore-router-id
- cluster cluster-id
- no cluster
- connect-retry seconds
- no connect-retry
- [no] damping
- description description-string
- no description
- [no] disable-4byte-asn
- [no] disable-client-reflect
- disable-communities [standard] [extended]
- no disable-communities
- [no] disable-fast-external-failover
- [no] enable-peer-tracking
- [no] enable-rr-vpn-forwarding
- export policy-name [policy-name…(up to 15 max)]
- no export
- family [ipv4] [vpn-ipv4] [ipv6] [vpn-ipv6] [l2-vpn] [ms-pw] [mvpn-ipv4] [route-target]
- no family
- hold-time seconds [strict]
- no hold-time
- import policy-name [policy-name …(up to 15 max)]
- no import
- keepalive seconds
- no keepalive
- local-preference local-preference
- no local-preference
- loop-detect {drop-peer | discard-route | ignore-loop | off}
- no loop-detect
- med-out {number | igp-cost}
- no med-out
- min-as-origination seconds
- no min-as-origination
- min-route-advertisement seconds
- no min-route-advertisement
- [no] mp-bgp-keep
- multihop ttl-value
- no multihop
- next-hop-resolution
- label-route-transport-tunnel
- family family
- resolution {any | filter | disabled}
- resolution-filter
- [no] ldp
- [no] rsvp
- [no] sr-isis
- [no] sr-ospf
- [no] outbound-route-filtering
- [no] extended-community
- [no] accept-orf
- send-orf [comm-id...(up to 32 max)]
- no send-orf comm-id
- [no] path-mtu-discovery
- preference preference
- purge-timer
- no purge-timer
- no preference
- rapid-update [l2-vpn] [mvpn-ipv4] [evpn]
- no rapid-update
- [no] rapid-withdrawal
- [no] remove-private [limited]
- router-id ip-address
- no router-id
- [no] shutdown
- [no] split-horizon
- [no] vpn-apply-export
- [no] vpn-apply-import
Group BGP commands
config
- router [router-name]
- [no] bgp
- [no] group name
- [no] add-paths
- ipv4 send send-limit
- ipv4 send send-limit receive [none]
- no ipv4
- ipv6 send send-limit
- ipv6 send send-limit receive [none]
- no ipv6
- vpn-ipv4 send send-limit
- vpn-ipv4 send send-limit receive [none]
- no vpn-ipv4
- vpn-ipv6 send send-limit
- vpn-ipv6 send send-limit receive [none]
- no vpn-ipv6
- [no] advertise-inactive
- [no] aggregator-id-zero
- [no] aigp
- authentication-key [authentication-key | hash-key] [hash | hash2]
- no authentication-key
- auth-keychain name
- cluster cluster-id
- no cluster
- connect-retry seconds
- no connect-retry
- [no] damping
- [no] default-route-target
- description description-string
- no description
- [no] disable-4byte-asn
- [no] disable-capability-negotiation
- [no] disable-client-reflect
- disable-communities [standard] [extended]
- no disable-communities
- [no] disable-fast-external-failover
- [no] enable-peer-tracking
- export policy-name [policy-name…(up to 15 max)]
- no export
- family [ipv4] [vpn-ipv4][ipv6] [vpn-ipv6] [l2-vpn] [ms-pw] [mvpn-ipv4] [route-target]
- no family
- hold-time seconds [strict]
- no hold-time
- import policy-name [policy-name …(up to 15 max)]
- no import
- keepalive seconds
- no keepalive
- local-address ip-address
- no local-address
- local-as as-number [private]
- no local-as
- local-preference local preference
- no local-preference
- loop-detect {drop-peer | discard-route | ignore-loop | off}
- no loop-detect
- med-out {number | igp-cost}
- no med-out
- min-as-origination seconds
- no min-as-origination
- min-route-advertisement seconds
- no min-route-advertisement
- multihop ttl-value
- no multihop
- no next-hop-self
- [no] outbound-route-filtering
- [no] extended-community
- [no] accept-orf
- send-orf [comm-id...(up to 32 max)]
- no send-orf [comm-id]
- [no] path-mtu-discovery
- peer-as as-number
- no peer-as
- preference preference
- no preference
- prefix-limit limit
- no prefix-limit
- [no] remove-private [limited]
- [no] shutdown
- type {internal | external}
- no type
- [no] vpn-apply-export
- [no] vpn-apply-import
Neighbor BGP commands
config
- router [router-name]
- [no] bgp
- [no] group name
- [no] neighbor ip-address
- [no] add-paths
- ipv4 send send-limit
- ipv4 send send-limit receive [none]
- no ipv4
- ipv6 send send-limit
- ipv6 send send-limit receive [none]
- no ipv6
- no vpn-ipv4
- vpn-ipv4 send send-limit
- vpn-ipv4 send send-limit receive [none]
- no vpn-ipv6
- vpn-ipv6 send send-limit
- vpn-ipv6 send send-limit receive [none]
- [no] advertise-inactive
- advertise-label [ipv4 [use-svc-routes]] [ipv6]
- [no] advertise-label
- [no] aggregator-id-zero
- [no] aigp
- auth-keychain name
- authentication-key [authentication-key | hash-key] [hash | hash2]
- no authentication-key
- cluster cluster-id
- no cluster
- connect-retry seconds
- no connect-retry
- [no] damping
- [no] default-route-target
- description description-string
- no description
- [no] disable-4byte-asn
- [no] disable-capability-negotiation
- [no] disable-client-reflect
- disable-communities [standard] [extended]
- no disable-communities
- [no] disable-fast-external-failover
- [no] enable-peer-tracking
- export policy-name [policy-name…(up to 15 max)]
- no export
- family [ipv4] [vpn-ipv4] [ipv6] [vpn-ipv6] [l2-vpn] [ms-pw] [mvpn-ipv4] [route-target]
- no family
- hold-time seconds [strict]
- no hold-time
- import policy-name [policy-name …(up to 15 max)]
- no import
- keepalive seconds
- no keepalive
- local-address ip-address
- no local-address
- local-as as-number [private]
- no local-as
- local-preference local-preference
- no local-preference
- loop-detect {drop-peer | discard-route | ignore-loop | off}
- no loop-detect
- med-out {number | igp-cost}
- no med-out
- min-as-origination seconds
- no min-as-origination
- min-route-advertisement seconds
- no min-route-advertisement
- multihop ttl-value
- no multihop
- no next-hop-self
- [no] outbound-route-filtering
- [no] extended-community
- [no] accept-orf
- send-orf [comm-id...(up to 32 max)]
- no send-orf [comm-id]
- [no] path-mtu-discovery
- peer-as as-number
- no peer-as
- preference preference
- no preference
- prefix-limit limit
- no prefix-limit
- [no] remove-private {limited}
- [no] shutdown
- type {internal | external}
- no type
- [no] vpn-apply-export
- [no] vpn-apply-import
Other BGP-related commands
config
- router [router-name]
- autonomous-system as-number
- no autonomous-system
Show commands
show
- router [router-instance]
- bgp
- auth-keychain keychain-name
- damping [ip-prefix[/prefix-length] [damp type | detail] [ipv4]
- damping [ip-prefix | prefix-length] [detail] vpn-ipv4
- group [name] [detail]
- neighbor [ip-address [detail]]
- neighbor [as-number [detail]]
- neighbor ip-address [family [type mvpn-type]] filter1 [brief]
- neighbor ip-address [family] filter2
- neighbor as-number [family] filter2
- neighbor ip-address orf [filter3]
- neighbor ip-address graceful-restart
- paths
- routes [family] [brief]
- routes [family] prefix [detail | longer | hunt [brief]]
- routes [family ] community comm-id
- routes l2-vpn l2vpn-type {[rd rd] | [siteid site-id] | [veid veid] [offset vpls-base-offset]}
- summary [all]
- summary [family family] [neighbor ip-address]
Clear commands
clear
- router
- bgp
- damping [{ip-prefix/ip-prefix-length] [neighbor ip-address]} | {group name}]
- flap-statistics [{ip-prefix/mask [neighbor ip-address] | [group group-name] | [regex reg-exp | policy policy-name}]
- neighbor {ip-address | as as-number | external | all} [soft | soft-inbound]
- neighbor {ip-address | as as-number | external | all} statistics
- neighbor ip-address end-of-rib
- protocol
Debug commands
debug
- router
- bgp
- events [neighbor ip-address | group name]
- no events
- keepalive [neighbor ip-address | group name]
- no keepalive
- notification [neighbor ip-address | group name]
- no notification
- open [neighbor ip-address | group name]
- no open
- [no] outbound-route-filtering
- packets [neighbor ip-address | group name]
- no packets
- route-refresh [neighbor ip-address | group name]
- no route-refresh
- rtm [neighbor ip-address | group name]
- no rtm
- socket [neighbor ip-address | group name]
- no socket
- timers [neighbor ip-address | group name]
- no timers
- update [neighbor ip-address | group name]
- no update
Command descriptions
Configuration commands
bgp
Syntax
[no] bgp
Context
config>router
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command enables the BGP protocol instance and BGP configuration context. BGP is administratively enabled upon creation.
The no form of this command deletes the BGP protocol instance and removes all configuration parameters for the BGP instance. BGP must be shutdown before deleting the BGP instance. An error occurs if BGP is not shutdown first.
add-paths
Syntax
[no] add-paths
Context
config>router>bgp
config>router>bgp>group
config>router>bgp>group>neighbor
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command enables the add-paths configuration context and enables add-paths to be configured for one or more BGP route types. The BGP add-paths capability allows the router to send and receive multiple paths per prefix to and from a peer.
The no form of this command (no add-paths) removes add-paths from the configuration of BGP, the group, or the neighbor, causing sessions established using add-paths to go down and come back up without the add-paths capability.
Default
no add-paths
ipv4
Syntax
ipv4 send send-limit receive [none]
ipv4 send send-limit
no ipv4
Context
config>router>bgp>add-paths
config>router>bgp>group>add-paths
config>router>bgp>group>neighbor>add-paths
Platforms
Supported on all 7210 SAS platforms as described in this document.
Description
This command configures the add-paths capability for IPv4 routes. By default, the add-paths capability is disabled for IPv4 routes.
Add-paths are supported only for the label-IPv4 family.
The maximum number of paths to send per IPv4 NLRI is the configured send-limit, which is a mandatory parameter. The capability to receive multiple paths per prefix from a peer is configurable using the optional receive keyword. If the receive keyword is not included in the command, the receive capability is enabled by default.
The no form of this command disables add-paths support for IPv4 routes, causing sessions established using add-paths for IPv4 to go down and come back up without the add-paths capability.
Default
no ipv4
Parameters
- send-limit
Specifies the maximum number of paths per IPv4 NLRI that are allowed to be advertised to add-path peers. The actual number of advertised routes may be less depending on the next-hop diversity requirement, other configuration options, route policies, and route advertisement rules.
- receive
Keyword to specify that the router negotiates the add-paths receive capability for IPv4 routes with its peers.
- none
Keyword to specify that the router does not negotiate the add-paths receive capability for IPv4 routes with its peers.
ipv6
Syntax
ipv6 send send-limit receive [none]
ipv6 send send-limit
no ipv6
Context
config>router>bgp>add-paths
config>router>bgp>group>add-paths
config>router>bgp>group>neighbor>add-paths
Platforms
Supported on all 7210 SAS platforms as described in this document.
Description
This command configures the add-paths capability for IPv6 routes. By default, the add-paths capability is disabled for IPv6 routes.
Add-paths are supported only for the label-IPv4 family.
The maximum number of paths to send per IPv6 NLRI is the configured send-limit, which is a mandatory parameter. The capability to receive multiple paths per prefix from a peer is configurable using the optional receive keyword. If the receive keyword is not included in the command, the receive capability is enabled by default.
The no form of this command disables add-paths support for IPv6 routes, causing sessions established using add-paths for IPv6 to go down and come back up without the add-paths capability.
Default
no ipv4
Parameters
- send-limit
Specifies the maximum number of paths per IPv6 NLRI that are allowed to be advertised to add-path peers. The actual number of advertised routes may be less depending on the next-hop diversity requirement, other configuration options, route policies, and route advertisement rules.
- receive
Keyword to specify that the router negotiates the add-paths receive capability for IPv6 routes with its peers.
- none
Keyword to specify that the router does not negotiate the add-paths receive capability for IPv6 routes with its peers.
vpn-ipv4
Syntax
vpn-ipv4 send send-limit receive [none]
vpn-ipv4 send send-limit
no vpn-ipv4
Context
config>router>bgp>add-paths
config>router>bgp>group>add-paths
config>router>bgp>group>neighbor>add-paths
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command configures the add-paths capability for VPN-IPv4 routes. By default, add-paths is not enabled for VPN-IPv4 routes.
The maximum number of paths per VPN-IPv4 NLRI to send is the configured send-limit, which is a mandatory parameter. The capability to receive multiple paths per prefix from a peer is configurable using the optional receive keyword. If the receive keyword is not included in the command, the receive capability is enabled by default.
The no form of this command disables add-paths support for VPN-IPv4 routes, causing sessions established using add-paths for VPN-IPv4 to go down and come back up without the add-paths capability.
Default
no vpn-ipv4
Parameters
- send-limit
Specifies the maximum number of paths per VPN-IPv4 NLRI that are allowed to be advertised to add-paths peers (the actual number of advertised routes may be less depending on the next-hop diversity requirement, other configuration options, route policies, or route advertisement rules).
- receive
Keyword to specify the router negotiates the add-paths receive capability for VPN-IPv4 routes with its peers.
- none
Keyword to specify the router does not negotiate the add-paths receive capability for VPN-IPv4 routes with its peers.
vpn-ipv6
Syntax
vpn-ipv6 send send-limit receive [none]
vpn-ipv6 send send-limit
no vpn-ipv6
Context
config>router>bgp>add-paths
config>router>bgp>group>add-paths
config>router>bgp>group>neighbor>add-paths
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command configures the add-paths capability for VPN-IPv6 routes. By default, add-paths is not enabled for VPN-IPv6 routes.
The maximum number of paths per VPN-IPv6 NLRI to send is the configured send-limit, which is a mandatory parameter. The capability to receive multiple paths per prefix from a peer is configurable using the optional receive keyword. If the receive keyword is not included in the command the receive capability is enabled by default.
The no form of this command disables add-paths support for VPN-IPv6 routes, causing sessions established using add-paths for VPN-IPv6 to go down and come back up without the add-paths capability.
Default
no vpn-ipv6
Parameters
- send-limit
Specifies the maximum number of paths per VPN-IPv6 NLRI that are allowed to be advertised to add-paths peers (the actual number of advertised routes may be less depending on the next-hop diversity requirement, other configuration options, route policies and/or route advertisement rules).
- receive
Keyword to specify the router negotiates the add-paths receive capability for VPN-IPv6 routes with its peers.
- none
Keyword to specify the router does not negotiate the Add-Paths receive capability for VPN-IPv6 routes with its peers.
advertise-inactive
Syntax
[no] advertise-inactive
Context
config>router>bgp
config>router>bgp>group
config>router>bgp>group>neighbor
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command enables the advertising of inactive BGP routes to other BGP peers. By default, BGP only advertises BGP routes to other BGP peers if a specific BGP route is chosen by the route table manager as the most preferred route within the system and is active in the forwarding plane. This command allows system administrators to advertise a BGP route even though it is not the most preferred route within the system for a specific destination.
The no form of this command disables the advertising of inactive BGP routers to other BGP peers.
Default
no advertise-inactive
advertise-label
Syntax
advertise-label [ipv4 [use-svc-routes]] [ipv6]
no advertise-label
Context
config>router>bgp>group>neighbor
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command configures the IPv4 or IPv6 transport peers to exchange RFC 3107-labeled IPv4 or IPv6 routes.
If IPv4 is enabled, all IPv4 routes advertised to the remote BGP peer are sent with an RFC 3107-formatted label for the destination route.
If IPv6 is enabled, all IPv6 routes advertised to the remote BGP peer are sent with an RFC 3107-formatted label for the destination route.
The optional use-svc-routes parameter limits the number of BGP 3107 IPv4 labeled routes that are installed in the MPLS FIB. If this parameter is specified, only those BGP 3107 labeled routes that are required by services or required for establishing a BGP session with a configured neighbor are installed in the MPLS FIB. The following conditions trigger the installation of the MPLS label into the MPLS FIB for the received BGP 3107 IPv4 labeled route:
configuration of SDP to use a BGP tunnel to the far end
dynamic creation of spoke-SDP binding when a route is received through BGP AD and the far end of the SDP binding is reachable using the labeled route
installation of VPN-IPv4 routes received from a PE that is reachable using the labeled route
configuration of a BGP session to a BGP peer, using the bgp>neighbor CLI command, and the BGP peer is reachable using the labeled route
on the 7210 SAS-R6 and 7210 SAS-R12, if this command is enabled along with the config router bgp enable-rr-vpn-forwarding command, only those BGP 3107 routes that are required to resolve the VPN-IPv4 or VPN-IPv6 routes, and for which the 7210 SAS node is swapping the VPN label, are added to the FIB (the rest are only held in the RIB)
other IP applications, such as FTP and SSH, do not trigger the installation of the IPv4 labeled routes into the MPLS FIB
The no form of this command disables all configured options.
Default
no advertise-label
Parameters
- ipv4
Keyword to specify the advertisement label address family for core IPv4 routes. This keyword can be specified only for an IPv4 peer.
- use-svc-routes
Keyword to enable the user to limit the number of BGP 3107 labeled routes that are installed in the MPLS FIB.
- ipv6
Keyword to specify the advertisement label address family for core IPv6 routes. This keyword can be specified only for an IPv6 peer.
aggregator-id-zero
Syntax
[no] aggregator-id-zero
Context
config>router>bgp
config>router>bgp>group
config>router>bgp>group>neighbor
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command sets the router ID in the BGP aggregator path attribute to zero when BGP aggregates routes. This prevents different routers within an AS from creating aggregate routes that contain different AS paths.
When BGP is aggregating routes, it adds the aggregator path attribute to the BGP update messages. By default, BGP adds the ASN and router ID to the aggregator path attribute.
When this command is enabled, BGP adds the router ID to the aggregator path attribute. This command is used at the group level to revert to the value defined under the global level, while this command is used at the neighbor level to revert to the value defined under the group level.
The no form of this command used at the global level reverts to default where BGP adds the ASN and router ID to the aggregator path attribute.
The no form of this command used at the group level reverts to the value defined at the global level.
The no form of this command used at the neighbor level reverts to the value defined at the group level.
Default
no aggregator-id-zero
aigp
Syntax
[no] aigp
Context
config>router>bgp>group
config>router>bgp>group>neighbor
Platforms
7210 SAS-Mxp, 7210 SAS-R6, and 7210 SAS-R12
Description
This command enables accumulated Interior Gateway Protocol (AIGP) path attribute support with one or more BGP peers. BGP path selection among routes with an associated AIGP metric is based on the end-to-end IGP metrics of the different BGP paths, even when these BGP paths span more than one AS and IGP instance.
The no form of this command disables AIGP path attribute support, removes the AIGP attribute from advertised routes, and causes the AIGP attribute in received routes to be ignored.
Default
no aigp
auth-keychain
Syntax
auth-keychain name
Context
config>router>bgp
config>router>bgp>group
config>router>bgp>group>neighbor
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command configures a TCP authentication keychain to use for the session. The keychain allows the rollover of authentication keys during the lifetime of a session.
Default
no auth-keychain
Parameters
- name
Specifies the name of the keychain, up to 32 characters, to use for the specified TCP session or sessions.
authentication-key
Syntax
authentication-key [authentication-key | hash-key] [hash | hash2]
no authentication-key
Context
config>router>bgp
config>router>bgp>group
config>router>bgp>group>neighbor
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command configures the BGP authentication key.
Authentication is performed between neighboring routers before setting up the BGP session by verifying the password. Authentication is performed using the MD-5 message based digest.
The no form of this command reverts to the default value.
Default
MD5 Authentication disabled
Parameters
- authentication-key
Specifies the authentication key. The key can be any combination of ASCII characters up to 255 characters (unencrypted). If spaces are used in the string, enclose the entire string in quotation marks (‟ ”).
- hash-key
Specifies the hash key. The key can be any combination of ASCII characters up to 342 characters (encrypted). If spaces are used in the string, enclose the entire string in quotation marks (‟ ”).
This is useful when a user must configure the parameter, but, for security purposes, the actual unencrypted key value is not provided.
- hash
Keyword to specify that the key is entered in an encrypted form. If the hash parameter is not used, the key is assumed to be in a non-encrypted, clear text form. For security, all keys are stored in encrypted form in the configuration file with the hash parameter specified.
- hash2
Keyword to specify that the key is entered in a more complex encrypted form. If the hash2 parameter is not used, the less encrypted hash form is assumed.
backup-path
Syntax
[no] backup-path [ipv4]
Context
config>router>bgp
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command enables the computation and use of a backup path for labeled IPv4 BGP-learned prefixes belonging to the base router. Multiple paths must be received for a prefix to take advantage of this feature. When a prefix has a backup path and its primary paths fail, the affected traffic is rapidly diverted to the backup path without waiting for control plane reconvergence to occur. When many prefixes share the same primary paths, and in some cases also the same backup path, the time to failover traffic to the backup path is independent of the number of prefixes.
By default, IPv4 prefixes do not have a backup path installed in the IOM.
The no form of this command disables the use of a backup path.
Default
no backup-path
Parameters
- ipv4
Keyword that enables BGP fast reroute for labeled IPv4 routes.
best-path-selection
Syntax
best-path-selection
Context
config>router>bgp
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command enables path selection configuration.
always-compare-med
Syntax
always-compare-med {zero | infinity}
no always-compare-med strict-as {zero | infinity}
no always-compare-med
Context
config>router>bgp>best-path-selection
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command configures the comparison of BGP routes based on the Multi-Exit Discriminator (MED) path attribute.
The default behavior of 7210 SAS (equivalent to the no form of this command) is to only compare two routes on the basis of MED if they have the same neighbor AS (the first non-confed AS in the received AS_PATH attribute). Also by default, a route without a MED attribute is handled the same as though it had a MED attribute with the value 0.
This command without the strict-as keyword allows MED to be compared even if the paths have a different neighbor AS; in this case, if neither the zero nor infinity keyword is specified, the zero option is inferred, meaning a route without a MED is handled as though it had a MED attribute with the value 0. When the strict-as keyword is present, MED is only compared between paths from the same neighbor AS; in this case, zero or infinity is mandatory and tells BGP how to interpret paths without a MED attribute.
The no form of this command only compares two routes on the basis of MED if they have the same neighbor AS.
Default
no always-compare-med
Parameters
- zero
Keyword to specify that for routes learned without a MED attribute, a zero (0) value is used in the MED comparison. The routes with the lowest metric are the most preferred.
- infinity
Keyword to specify that for routes learned without a MED attribute, a value of infinity (2^32-1) is used in the MED comparison. This in effect makes these routes the least desirable.
- strict-as
Keyword to specify that BGP paths are to be compared even with different neighbor AS.
as-path-ignore
Syntax
as-path-ignore [ipv4] [vpn-ipv4] [l2-vpn] [mvpn-ipv4]
no as-path-ignore
Context
config>router>bgp>best-path-selection
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command specifies whether the AS path is used to determine the best BGP route.
If this command is enabled, the AS paths of incoming routes are not used in the route selection process.
The no form of this command removes the parameter from the configuration.
Default
no as-path-ignore
Parameters
- ipv4
Keyword to specify that the AS-path length is ignored for all IPv4 routes.
- vpn-ipv4
Keyword to specify that the length AS-path is ignored for all IPv4 VPRN routes.
- l2-vpn
Keyword to specify that the AS-path length is ignored for all L2-VPN NLRIs.
- mvpn-ipv4
Keyword to specify that the AS-path length is ignored for all mVPN IPv4 multicast routes. Supported on 7210 SAS-T, 7210 SAS-R6, 7210 SAS-R12, 7210 SAS-Sx/S 1/10GE (standalone and standalone-VC), 7210 SAS-Sx 10/100GE, and 7210 SAS-Mxp devices only.
ignore-nh-metric
Syntax
ignore-nh-metric
no ignore-nh-metric
Context
config>router>bgp>best-path-selection
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command configures BGP to disregard the resolved distance to the BGP next hop in its decision process for selecting the best route to a destination.
When configured in the config>router>bgp>best-path-selection context, this command applies to the comparison of two BGP routes with the same NLRI learned from base router BGP peers. When configured in the config>service>vprn context, this command applies to the comparison of two BGP-VPN routes for the same IP prefix imported into the VPRN from the base router BGP instance. When configured in the config>service>vprn>bgp>best-path-selection context, this command applies to the comparison of two BGP routes for the same IP prefix learned from VPRN BGP peers.
The no form of this command reverts to the default behavior whereby BGP factors the distance to the next hop into its decision process.
Default
no ignore-nh-metric
ignore-router-id
Syntax
ignore-router-id
no ignore-router-id
Context
config>router>bgp>best-path-selection
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command modifies the route selection behavior.
When the this command is enabled and the current best path to a destination was learned from eBGP peer X with BGP identifier x, new paths that are received from eBGP peer Y with BGP identifier y and are equivalent do not change the best path even if y is less than x during BGP identifier comparison.
The no form of this command reverts to the default behavior of selecting the route with the lowest BGP identifier (y) as best.
Default
no ignore-router-id
cluster
Syntax
cluster cluster-id
no cluster
Context
config>router>bgp
config>router>bgp>group
config>router>bgp>group>neighbor
Platforms
7210 SAS-R6 and 7210 SAS-R12
Description
This command configures the cluster ID for a route reflector server.
Route reflectors reduce the number of iBGP sessions required within an AS. Normally, all BGP speakers within an AS must have a BGP peering with every other BGP speaker in an AS. A route reflector and its clients form a cluster. Peers that are not part of the cluster are considered to be non-clients.
When a route reflector receives a route, it must first select the best path from all the paths received. If the route was received from a non-client peer, the route reflector sends the route to all clients in the cluster. If the route came from a client peer, the route reflector sends the route to all non-client peers and to all client peers except the originator.
For redundancy, a cluster can have multiple route reflectors.
The no form of this command deletes the cluster ID and disables the route reflection at the global BGP level or for the specified group or neighbor.
Default
no cluster
Parameters
- cluster-id
Specifies the route reflector cluster ID, expressed in dotted-decimal notation.
connect-retry
Syntax
connect-retry seconds
no connect-retry
Context
config>router>bgp
config>router>bgp>group
config>router>bgp>group>neighbor
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command configures the BGP connect retry timer value.
When this timer expires, BGP tries to reconnect to the configured peer. This configuration parameter can be set at three levels: global level (applies to all peers), peer-group level (applies to all peers in group) or neighbor level (only applies to specified peer). The most specific value is used.
The no form of this command used at the global level reverts to the default value.
The no form of this command used at the group level reverts to the value defined at the global level.
The no form of this command used at the neighbor level reverts to the value defined at the group level.
Default
connect-retry 120
Parameters
- seconds
Specifies the BGP connect retry timer value, in seconds, expressed as a decimal integer.
damping
Syntax
[no] damping
Context
config>router>bgp
config>router>bgp>group
config>router>bgp>group>neighbor
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command enables BGP route damping for learned routes that are defined within the route policy. Use damping to reduce the number of update messages sent between BGP peers and reduce the load on peers without affecting the route convergence time for stable routes. Damping parameters are set through route policy definition.
The no form of this command used at the global level reverts route damping.
The no form of this command used at the group level reverts to the value defined at the global level.
The no form of this command used at the neighbor level reverts to the value defined at the group level.
When damping is enabled and the route policy does not specify a damping profile, the default damping profile is used. This profile is always present and consists of the following parameters:
Half-life: |
15 minutes |
Max-suppress: |
60 minutes |
Suppress-threshold: |
3000 |
Reuse-threshold: |
750 |
Default
no damping
default-route-target
Syntax
[no] default-route-target
Context
config>router>bgp>group
config>router>bgp>group>neighbor
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command originates the default RTC route (zero prefix length) toward the selected peers.
The no form of this command disables the advertisement of the default RTC route.
Default
no default-route-target
description
Syntax
description description-string
no description
Context
config>router>bgp
config>router>bgp>group
config>router>bgp>group>neighbor
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command enables a text description stored in the configuration file for a configuration context.
The no form of this command removes the description string from the context.
Parameters
- string
Specifies the description character string. Allowed values are any string up to 80 characters composed of printable, 7-bit ASCII characters. If the string contains special characters (#, $, spaces, and so on), the entire string must be enclosed within double quotes.
disable-4byte-asn
Syntax
[no] disable-4byte-asn
Context
config>router>bgp
config>router>bgp>group
config>router>bgp>group>neighbor
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command disables the use of 4-byte ASNs. It can be configured at all three level of the hierarchy so it can be specified down to the per peer basis.
If this command is enabled, 4-byte ASN support should not be negotiated with the associated remote peers.
The no form of this command reverts to the default behavior, which is to enable the use of 4-byte ASN.
disable-capability-negotiation
Syntax
[no] disable-capability-negotiation
Context
config>router>bgp>group
config>router>bgp>group>neighbor
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command disables the exchange of capabilities when the command is enabled. After the peering is flapped, any new capabilities are not negotiated and strictly support IPv4 routing exchanges with that peer.
The no form of this command removes this command from the configuration and reverts to the default behavior.
Default
no disable-capability-negotiation
disable-client-reflect
Syntax
[no] disable-client-reflect
Context
config>router>bgp
config>router>bgp>group
config>router>bgp>group>neighbor
Platforms
7210 SAS-R6 and 7210 SAS-R12
Description
This command disables the reflection of routes by the route reflector at the BGP, group, or neighbor level.
This command only disables the reflection of routes from other client peers. Routes learned from non-client peers are still reflected to all clients.
The no form of this command re-enables client reflection of routes.
Default
no disable-client-reflect
disable-communities
Syntax
disable-communities [standard] [extended]
no disable-communities
Context
config>router>bgp
config>router>bgp>group
config>router>bgp>group>neighbor
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command configures BGP to disable sending communities.
Parameters
- standard
Keyword to specify standard communities that existed before VPRNs or 2547.
- extended
Keyword to specify BGP communities used were expanded after the concept of 2547 was introduced, to include handling the VRF target.
disable-fast-external-failover
Syntax
[no]disable-fast-external-failover
Context
config>router>bgp
config>router>bgp>group
config>router>bgp>group>neighbor
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command configures BGP fast external failover.
disallow-igp
Syntax
[no] disallow-igp
Context
config>router>bgp
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command enables the use of the IGP next hop to the BGP next hop as the next hop of last resort.
enable-peer-tracking
Syntax
[no] enable-peer-tracking
Context
config>router>bgp
config>router>bgp>group
config>router>bgp>group>neighbor
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command enables BGP peer tracking. BGP peer tracking allows a BGP peer to be dropped immediately if the route used to resolve the BGP peer address is removed from the IP routing table, and there is no alternative available. The BGP peer does not wait for the hold timer to expire; therefore, the BGP reconvergence process is accelerated.
The no form of this command disables peer tracking.
Default
no enable-peer-tracking
enable-rr-vpn-forwarding
Syntax
[no] enable-rr-vpn-forwarding
Context
config>router>bgp
Platforms
7210 SAS-R6 and 7210 SAS-R12
Description
This command enables a route reflector of VPN-IP routes to be deployed in the datapath between two BGP peers (a peer X and a peer Y) in a next-hop resolution.
Scaling and convergence should be considered before enabling this command.
When this command is configured, all received VPN-IP routes, regardless of route target, are imported into the dummy VRF, where the BGP next hops are resolved. The label-route-transport-tunnel command in the config>router>bgp>next-hop-resolution context determines what types of tunnels are eligible to resolve the next hops.
If a received VPN-IP route from iBGP peer X is resolved and selected as best so that it can be readvertised to an iBGP peer Y, and the BGP next hop is modified toward peer Y (by using the next-hop-self command in the Y group or neighbor context, or by using the next-hop action command in an export policy applied to Y), BGP allocates a new VPN service label value for the route, signals that new label value to Y, and programs the IOM to do the corresponding label swap operation. The supported combinations of X and Y are the following:
from X (client) to Y (client)
from X (client) to Y (non-client)
from X (non-client) to Y (client)
The no form of this command causes the route to be readvertised without a new service label, or a new service label to not be advertised between the two peers.
Default
no enable-rr-vpn-forwarding
export
Syntax
export policy-name [policy-name…up to 15 max]
no export [policy-name]
Context
config>router>bgp
config>router>bgp>group
config>router>bgp>group>neighbor
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command specifies the export route policy used to determine which routes are advertised to peers. Route policies are configured in the config>router>policy-options context.
This configuration parameter can be set at three levels: global level (applies to all peers), group level (applies to all peers in peer-group), or neighbor level (only applies to specified peer). The most specific level is used.
When multiple policy names are specified, the policies are evaluated in the order they are specified. A maximum of 15 policy names can be configured. The first policy that matches is applied.
When multiple export commands are issued, the last command entered overrides the previous command.
When no export policies are specified, BGP routes are advertised and non-BGP routes are not advertised by default.
The no form of this command removes the policy association with the BGP instance. To remove association of all policies, use the no export command without arguments.
Default
no export
Parameters
- policy-name
Specifies the route policy name. Allowed values are any string up to 32 characters composed of printable, 7-bit ASCII characters. If the string contains special characters (#, $, spaces, and so on), the entire string must be enclosed within double quotes.
family
Syntax
family [ipv4] [vpn-ipv4] [ipv6] [vpn-ipv6] [l2-vpn] [ms-pw] [mvpn-ipv4] [route-target]
no family
Context
config>router>bgp
config>router>bgp>group
config>router>bgp>group>neighbor
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command specifies the address family or families to support over BGP peerings in the base router. This command is additive; entering the family command adds the specified address family to the list.
The no form of this command removes the specified address family from the associated BGP peerings. If an address family is not specified, the supported address family is reset back to the default.
Default
family ipv4
Parameters
- ipv4
Keyword to provision support for IPv4 routing information.
- vpn-ipv4
Keyword word to exchange IPv4 VPN routing information.
- ms-pw
Keyword to exchange dynamic MS-PW related information.
- ipv6
Keyword to exchange IPv6 routing information.
- vpn-ipv6
Keyword to exchange IPv6 VPN routing information.
- l2-vpn
Keyword to exchange Layer 2 VPN information.
- mvpn-ipv4
Keyword to exchange multicast VPN related information. This keyword is supported only on the 7210 SAS-Mxp, 7210 SAS-R6, 7210 SAS-R12, 7210 SAS-Sx/S 1/10GE (standalone and standalone-VC), and 7210 SAS-T (network). This family is not supported for 7210 SAS-Sx 10/100GE devices.
- route-target
Keyword to exchange RT constrained route information.
split-horizon
Syntax
[no] split-horizon
Context
config>router>bgp
config>router>bgp>group
config>router>bgp>group>neighbor
Platforms
7210 SAS-R6 and 7210 SAS-R12
Description
This command enables the use of split horizon. Split horizon prevents routes from being reflected back to a peer that sends the best route. It applies to routes of all address families and to eBGP or iBGP sending peers.
The no form of this command means that no effort is taken to prevent a best route from being reflected back to the sending peer.
Default
no split-horizon
vpn-apply-export
Syntax
[no] vpn-apply-export
Context
config>router>bgp
config>router>bgp>group
config>router>bgp>group>neighbor
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command causes the base instance BGP export route policies to be applied to VPN-IPv4 routes.
The no form of this command disables the application of the base instance BGP route policies to VPN-IPv4 routes.
Default
no vpn-apply-export
vpn-apply-import
Syntax
[no] vpn-apply-import
Context
config>router>bgp
config>router>bgp>group
config>router>bgp>group>neighbor
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command causes the base instance BGP import route policies to be applied to VPN-IPv4 routes.
The no form of this command disables the application of the base instance BGP import route policies to VPN-IPv4 routes.
Default
no vpn-apply-import
group
Syntax
[no] group name
Context
config>router>bgp
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
Commands in this context configure a BGP peer group.
The no form of this command deletes the specified peer group and all configurations associated with the peer group. The group must be shutdown before it can be deleted.
Parameters
- name
Specifies the peer group name. Allowed values are any string up to 32 characters composed of printable, 7-bit ASCII characters. If the string contains special characters (#, $, spaces, and so on), the entire string must be enclosed within double quotes.
hold-time
Syntax
hold-time seconds [strict]
no hold-time
Context
config>router>bgp
config>router>bgp>group
config>router>bgp>group>neighbor
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command configures the BGP hold time, expressed in seconds.
The BGP hold time specifies the maximum time BGP waits between successive messages (either keepalive or update) from its peer, before closing the connection. This configuration parameter can be set at three levels: global level (applies to all peers), group level (applies to all peers in group), or neighbor level (only applies to specified peer). The most specific value is used.
Even though the 7210 SAS implementation allows setting the keepalive time separately, the configured keepalive timer is overridden by the hold-time value under the following circumstances.
If the specified hold-time is less than the configured keepalive time, the operational keepalive time is set to a third of the hold-time; the configured keepalive time is not changed.
If the hold-time is set to zero, the operational value of the keepalive time is set to zero; the configured keepalive time is not changed. This means that the connection with the peer is up permanently and no keepalive packets are sent to the peer.
The no form of this command used at the global level reverts to the default value.
The no form of this command used at the group level reverts to the value defined at the global level.
The no form of this command used at the neighbor level reverts to the value defined at the group level.
Default
hold-time 90
Parameters
- seconds
Specifies the hold-time, in seconds, expressed as a decimal integer. A value of 0 indicates the connection to the peer is up permanently.
- strict
Keyword to specify that the advertised BGP hold-time from the far-end BGP peer must be greater than or equal to the specified value.
import
Syntax
import policy-name [policy-name…up to 15 max]
no import [policy-name]
Context
config>router>bgp
config>router>bgp>group
config>router>bgp>group>neighbor
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command specifies the import route policy to use to determine which routes are accepted from peers. Route policies are configured in the config>router>policy-options context.
This configuration parameter can be set at three levels: global level (applies to all peers), group level (applies to all peers in peer-group), or neighbor level (only applies to specified peer). The most specific level is used.
When multiple policy names are specified, the policies are evaluated in the order they are specified. A maximum of 15 policy names can be specified. The first policy that matches is applied.
When multiple import commands are issued, the last command entered overrides the previous command.
When an import policy is not specified, BGP routes are accepted by default.
The no form of this command removes the policy association with the BGP instance. To remove association of all policies, use no import without arguments.
Default
no import
Parameters
- policy-name
Specifies the route policy name. Allowed values are any string up to 32 characters composed of printable, 7-bit ASCII characters. If the string contains special characters (#, $, spaces, and so on), the entire string must be enclosed within double quotes.
keepalive
Syntax
keepalive seconds
no keepalive
Context
config>router>bgp
config>router>bgp>group
config>router>bgp>group>neighbor
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command configures the BGP keepalive timer. A keepalive message is sent every time this timer expires.
The keepalive parameter can be set at three levels: global level (applies to all peers), group level (applies to all peers in peer-group), or neighbor level (only applies to specified peer). The most specific value is used.
The keepalive value is generally one third of the hold-time interval. The 7210 SAS implementation allows the keepalive value and the hold-time interval to be independently set; however, under the following circumstances, the configured keepalive value is overridden by the hold-time value.
If the specified keepalive value is greater than the configured hold-time, the specified value is ignored, and keepalive is set to one-third of the current hold-time value.
If the specified hold-time interval is less than the configured keepalive value, the keepalive value is reset to one third of the specified hold-time interval.
If the hold-time interval is set to zero, the configured the keepalive value is ignored. This means that the connection with the peer is up permanently and no keepalive packets are sent to the peer.
The no form of this command used at the global level reverts to the default value.
The no form of this command used at the group level reverts to the value defined at the global level.
The no form of this command used at the neighbor level reverts to the value defined at the group level.
Default
keepalive 30
Parameters
- seconds
Specifies the keepalive timer, in seconds, expressed as a decimal integer.
local-address
Syntax
local-address ip-address
no local-address
Context
config>router>bgp>group
config>router>bgp>group>neighbor
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command configures the local IP address used by the group or neighbor when communicating with BGP peers.
Outgoing connections use the local-address as the source of the TCP connection when initiating connections with a peer.
When a local address is not specified, 7210 SAS uses the system IP address when communicating with iBGP peers and uses the interface address for directly connected EBGP peers. This command is used at the neighbor level to revert to the value defined under the group level.
The no form of this command removes the configured local address for BGP.
The no form of this command used at the group level reverts to the value defined at the global level.
The no form of this command used at the neighbor level reverts to the value defined at the group level.
Default
no local-address
Parameters
- ip-address
Specifies the local address expressed in dotted decimal notation. Allowed value is a valid routable IP address on the router, either an interface or system IP address.
local-as
Syntax
local-as as-number [private]
no local-as
Context
config>router>bgp
config>router>bgp>group
config>router>bgp>group>neighbor
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command configures a BGP virtual autonomous system (AS) number.
In addition to the ASN configured for BGP in the config>router>autonomous-system context, a virtual (local) ASN is configured.The virtual ASN is added to the as-path message before the router ASN makes the virtual AS the second AS in the as-path.
This command can be configured at three levels: global level (applies to all peers), group level (applies to all peers in peer-group), or neighbor level (only applies to specified peer). By specifying this command at each neighbor level, it is possible to have a separate AS number for each eBGP session.
When a command is entered multiple times for the same AS, the last command entered is used in the configuration. Add or remove the private keyword dynamically by reissuing the command.
Changing the local AS at the global level in an active BGP instance causes the BGP instance to restart with the new local ASN. Changing the local AS at the global level in an active BGP instance causes BGP to reestablish the peer relationships with all peers in the group with the new local ASN. Changing the local AS at the neighbor level in an active BGP instance causes BGP to reestablish the peer relationship with the new local ASN.
This is an optional command and can be used in a circumstance like the following example. Provider router P is moved from AS1 to AS2. The customer router that is connected to P, however, is configured to belong to AS1. To avoid reconfiguring the customer router, the local-as value on router P can be set to AS1. Therefore, router P adds AS1 to the as-path message for routes it advertises to the customer router.
The no form of this command used at the global level removes any virtual ASN configured.
The no form of this command used at the group level reverts to the value defined at the global level.
The no form of this command used at the neighbor level reverts to the value defined at the group level.
Default
no local-as
Parameters
- as-number
Specifies the virtual AS number, expressed as a decimal integer.
- private
Keyword to specify that the local AS is hidden in paths learned from the peering.
local-preference
Syntax
local-preference local-preference
no local-preference
Context
config>router>bgp
config>router>bgp>group
config>router>bgp>group>neighbor
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command configures the BGP local preference attribute in incoming routes, if not specified, and configures the default value for the attribute.
This command is used if the BGP route arrives from a BGP peer without the local-preference command configured.
The specified value can be overridden by any value set via a route policy. This configuration parameter can be set at three levels: global level (applies to all peers), group level (applies to all peers in peer-group), or neighbor level (only applies to specified peer). The most specific value is used.
The no form of this command at the global level specifies that incoming routes with local-preference set are not overridden, and routes arriving without local-preference set are interpreted as if the route had local-preference value of 100.
The no form of this command used at the group level reverts to the value defined at the global level.
The no form of this command used at the neighbor level reverts to the value defined at the group level.
Default
no local-preference
Parameters
- local-preference
Specifies the local preference value to use as the override value, expressed as a decimal integer.
loop-detect
Syntax
loop-detect {drop-peer | discard-route | ignore-loop | off}
no loop-detect
Context
config>router>bgp
config>router>bgp>group
config>router>bgp>group>neighbor
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command configures how the BGP peer session handles loop detection in the AS path.
This command can be set at three levels: global level (applies to all peers), group level (applies to all peers in peer-group), or neighbor level (only applies to specified peer). The most specific value is used.
Dynamic configuration changes of loop-detect are not recognized.
The no form of this command used at the global level reverts to the default value.
The no form of this command used at the group level reverts to the value defined at the global level.
The no form of this command used at the neighbor level reverts to the value defined at the group level.
Default
loop-detect ignore-loop
Parameters
- drop-peer
Keyword that sends a notification to the remote peer and drops the session.
- discard-route
Keyword that discards routes received from a peer with the same ASN as the router. This option prevents routes looped back to the router from being added to the routing information base and consuming memory. When this option is changed, the change is not active for an established peer until the connection is reestablished for the peer.
- ignore-loop
Keyword that ignores routes with loops in the AS path but maintains peering.
- off
Keyword that disables loop detection.
med-out
Syntax
med-out {number | igp-cost}
no med-out
Context
config>router>bgp
config>router>bgp>group
config>router>bgp>group>neighbor
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command enables advertising the MED and assigns the value used for the path attribute for the MED advertised to BGP peers if the MED is not already set.
The specified value can be overridden by any value set via a route policy.
This command can be set at three levels: global level (applies to all peers), group level (applies to all peers in peer-group), or neighbor level (only applies to specified peer). The most specific value is used.
The no form of this command used at the global level reverts to default where the MED is not advertised.
The no form of this command used at the group level reverts to the value defined at the global level.
The no form of this command used at the neighbor level reverts to the value defined at the group level.
Default
no med-out
Parameters
- number
Specifies the MED path attribute value expressed as a decimal integer.
- igp-cost
Keyword to specify the MED is set to the IGP cost of the specific IP prefix.
min-as-origination
Syntax
min-as-origination seconds
no min-as-origination
Context
config>router>bgp
config>router>bgp>group
config>router>bgp>group>neighbor
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command configures the minimum interval at which a path attribute, originated by the local router, can be advertised to a peer.
This command can be set at three levels: global level (applies to all peers), group level (applies to all peers in peer-group), or neighbor level (only applies to specified peer). The most specific value is used.
The no form of this command used at the global level reverts to the default value.
The no form of this command used at the group level reverts to the value defined at the global level.
The no form of this command used at the neighbor level reverts to the value defined at the group level.
Default
min-as-origination 15
Parameters
- seconds
Specifies the minimum path attribute advertising interval, in seconds, expressed as a decimal integer.
min-route-advertisement
Syntax
min-route-advertisement seconds
no min-route-advertisement
Context
config>router>bgp
config>router>bgp>group
config>router>bgp>group>neighbor
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command configures the minimum interval at which a prefix can be advertised to a peer.
This command can be set at three levels: global level (applies to all peers), group level (applies to all peers in peer-group), or neighbor level (only applies to specified peer). The most specific value is used.
The no form of this command used at the global level reverts to default value.
The no form of this command used at the group level reverts to the value defined at the global level.
The no form of this command used at the neighbor level reverts to the value defined at the group level.
Default
min-route-advertisement 30
Parameters
- seconds
Specifies the minimum route advertising interval, in seconds, expressed as a decimal integer.
mp-bgp-keep
Syntax
[no] mp-bgp-keep
Context
config>router>bgp
Description
When this command is enabled, route refresh messages are not required or issued when VPN route policy changes are made; RIB-IN retains all MP-BGP routes.
The no form of this command disables the feature.
Default
no mp-bgp-keep
multihop
Syntax
multihop ttl-value
no multihop
Context
config>router>bgp
config>router>bgp>group
config>router>bgp>group>neighbor
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command configures the time to live (TTL) value entered in the IP header of packets sent to an eBGP peer multiple hops away.
The no form of this command conveys to the BGP instance that the eBGP peers are directly connected.
The no form of this command used at the global level reverts to the default value.
The no form of this command used at the group level reverts to the value defined at the global level.
The no form of this command used at the neighbor level reverts to the value defined at the group level.
Default
multihop 1 (eBGP peers are directly connected)
multihop 64 (iBGP)
Parameters
- ttl-value
Specifies the TTL value, expressed as a decimal integer.
next-hop-self
Syntax
[no] next-hop-self
Context
config>router>bgp>group
config>router>bgp>group>neighbor
Platforms
7210 SAS-R6 and 7210 SAS-R12
Description
This command configures BGP to advertise routes to members of a group or to a specific neighbor using a local address of the BGP instance as the BGP next-hop address. This command is set regardless of the route source (eBGP or iBGP) or its family. When used with VPN-IPv4 and VPN-IPv6 routes, the enable-rr-vpn-forwarding command should also be configured.
The no form of this command uses standard protocol behavior to decide whether to set next-hop-self in advertised routes.
Default
no next-hop-self
next-hop-resolution
Syntax
next-hop-resolution
Context
config>router>bgp
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
Commands in this context configure next-hop resolution.
label-route-transport-tunnel
Syntax
label-route-transport-tunnel
Context
config>router>bgp>next-hop-resolution
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
Commands in this context configure the binding of BGP labeled routes to tunnels.
family
Syntax
family family
Context
config>router>bgp>next-hop-res>label-route-transport-tunnel
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command configures the binding of BGP labeled routes to tunnels for a specific family.
Default
family ipv4
Parameters
- family
Specifies the family.
resolution
Syntax
resolution {any | filter | disabled}
Context
config>router>bgp>next-hop-res>lbl-rt-tunn>family
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command configures the resolution state of BGP labeled routes using tunnels to BGP peers.
Default
resolution filter
Parameters
- any
Keyword that enables binding to any supported tunnel type in the BGP label route context following TTM preference.
- filter
Keyword that enables binding to the subset of tunnel types configured under the resolution-filter context.
- disabled
Keyword that disables the resolution of BGP label routes using tunnels to BGP peers.
resolution-filter
Syntax
resolution-filter
Context
config>router>bgp>next-hop-res>lbl-rt-tunn>family
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
Commands in this context configure the subset of tunnel types used in the resolution of BGP label routes using tunnels to BGP peers.
ldp
Syntax
[no] ldp
Context
config>router>bgp>next-hop-res>lbl-rt-tunn>family>resolution-filter
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command configures LDP tunneling for next-hop resolution.
rsvp
Syntax
[no] rsvp
Context
config>router>bgp>next-hop-res>lbl-rt-tunn>family>resolution-filter
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command configures RSVP tunneling for next-hop resolution.
Default
no rsvp
sr-isis
Syntax
[no] sr-isis
Context
config>router>bgp>next-hop-res>lbl-rt-tunn>family>resolution-filter
Platforms
7210 SAS-Mxp, 7210 SAS-Sx/S 1/10GE (standalone mode), and 7210 SAS-Sx 10/100GE (standalone mode)
Description
This command selects the SR tunnel type programmed by an IS-IS instance in the TTM for next-hop resolution and specifies SR tunnels (shortest path) to destinations reachable by the IS-IS protocol.
This command allows BGP to use the SR tunnel in the tunnel table submitted by the lowest preference IS-IS instance or, in the case of IS-IS instances with the same lowest preference, the IS-IS instance with the lowest ID number.
Default
no sr-isis
sr-ospf
Syntax
[no] sr-ospf
Context
config>router>bgp>next-hop-res>lbl-rt-tunn>family>resolution-filter
Platforms
7210 SAS-Mxp, 7210 SAS-Sx/S 1/10GE (standalone mode), and 7210 SAS-Sx 10/100GE (standalone mode)
Description
This command selects the SR tunnel type programmed by an OSPF instance in the TTM for next-hop resolution and specifies SR tunnels (shortest path) to destinations reachable by the OSPF protocol.
This command allows BGP to use the SR tunnel in the tunnel table submitted by the lowest preference OSPF instance or, in the case of OSPF instances with the same lowest preference, the OSPF instance with the lowest ID number.
Default
no sr-ospf
outbound-route-filtering
Syntax
[no] outbound-route-filtering
Context
config>router>bgp
config>router>bgp>group
config>router>bgp>group>neighbor
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command opens the configuration tree for sending or accepting BGP filter lists from peers (outbound route filtering).
Default
no outbound-route-filtering
extended-community
Syntax
[no] extended-community
Context
config>router>bgp>orf
config>router>bgp>group>orf
config>router>bgp>group>neighbor>orf
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
Commands in this context configure sending or accepting extended-community-based BGP filters.
For the no form of the command to work, all subcommands (send-orf, accept-orf) must be removed first.
accept-orf
Syntax
[no] accept-orf
Context
config>router>bgp>orf>ext-comm
config>router>bgp>group>orf>ext-comm
config>router>bgp>group>neighbor>orf>ext-comm
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command instructs the router to negotiate the receive capability in the BGP ORF negotiation with a peer and to accept filters that the peer wants to send.
The no form of this command causes the router to remove the accept capability in the BGP ORF negotiation with a peer and to clear any existing ORF filters that are currently in place.
send-orf
Syntax
send-orf [comm-id...(up to 32 max)]
no send-orf [comm-id]
Context
config>router>bgp>orf>ext-comm
config>router>bgp>group>orf>ext-comm
config>router>bgp>group>neighbor>orf>ext-comm
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command instructs the router to negotiate the send capability in the BGP outbound route filtering (ORF) negotiation with a peer.
This command also causes the router to send a community filter, prefix filter, or AS path filter configured as an inbound filter on the BGP session to its peer as an ORF Action ADD.
The no form of this command causes the router to remove the send capability in the BGP ORF negotiation with a peer.
The no form also causes the router to send an ORF remove action for a community filter, prefix filter, or AS path filter configured as an inbound filter on the BGP session to its peer.
If the comm-id parameters are not exclusively route target communities, the router extracts appropriate route targets and uses those. If the comm-id parameters specified contain no route targets, the router does not send an ORF.
Default
no send-orf
Parameters
- comm-id
Specifies a community policy that consists exclusively of route target extended communities. If the policy is not specified, the ORF policy is automatically generated from configured route target lists, accepted client route target ORFs, and locally configured route targets.
neighbor
Syntax
[no] neighbor ip-address
Context
config>router>bgp>group
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command creates a BGP peer/neighbor instance within the context of the BGP group.
This command can be issued repeatedly to create multiple peers and their associated configuration.
The no form of this command removes the specified neighbor and the entire configuration associated with the neighbor. The neighbor must be administratively shut down before attempting to delete it. If the neighbor is not shut down, the command does not result in any action except a warning message on the console indicating that the neighbor is still administratively up.
Parameters
- ip-address
Specifies the IP address of the BGP peer router, in dotted decimal notation.
peer-as
Syntax
peer-as as-number
Context
config>router>bgp>group
config>router>bgp>group>neighbor
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command configures the AS number for the remote peer. The peer AS number must be configured for each configured peer.
For eBGP peers, the peer AS number configured must be different from the AS number configured for this router under the global level, because the peer is in a different AS than this router.
For iBGP peers, the peer AS number must be the same as the AS number of this router configured under the global level.
This is a required command for each configured peer. This command can be configured under the group level for all neighbors in a particular group.
Parameters
- as-number
Specifies the AS number, expressed as a decimal integer.
path-mtu-discovery
Syntax
[no] path-mtu-discovery
Context
config>router>bgp
config>router>bgp>group
config>router>bgp>group>neighbor
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command enables path MTU discovery for the associated TCP connections. In doing so, the MTU for the associated TCP session is initially set to the egress interface MTU. The DF bit is also set so that if a router along the path of the TCP connection cannot handle a packet of a particular size without fragmenting, an ICMP message is sent back to set the path MTU for the specific session to a lower value that can be forwarded without fragmenting.
The no form of this command disables path MTU discovery.
Default
no path-mtu-discovery
preference
Syntax
[no] preference preference
Context
config>router>bgp
config>router>bgp>group
config>router>bgp>group>neighbor
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command configures the route preference for routes learned from the configured peers.
This command can be set at three levels: global level (applies to all peers), group level (applies to all peers in peer-group), or neighbor level (only applies to specified peer). The most specific value is used.
The lower the preference, the higher the chance of the route being the active route. The 7210 SAS assigns BGP routes highest default preference compared to routes that are direct, static, or learned through MPLS or OSPF.
The no form of this command used at the global level reverts to default value.
The no form of this command used at the group level reverts to the value defined at the global level.
The no form of this command used at the neighbor level reverts to the value defined at the group level.
Default
preference 170
Parameters
- preference
Specifies the route preference, expressed as a decimal integer.
purge-timer
Syntax
[no] purge-timer minutes
Context
config>router>bgp
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command configures the maximum time before stale routes are purged.
Parameters
- minutes
Specifies the duration of the purge timer, in minutes.
rapid-update
Syntax
rapid-update [l2-vpn] [mvpn-ipv4] [evpn]
no rapid-update
Context
config>router>bgp
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command enables BGP rapid update for specified address families.
If rapid update is enabled for a set of address families, and a route belonging to a family in that set is received by the router and chosen for propagation to specific BGP peers, the remaining time on the MRAI timer of these peers is ignored and the route is transmitted immediately, along with all other pending routes for these peers, including routes of address families not specified in the rapid-update command.
The rapid-update command overrides the peer-level time and applies the minimum setting of 0 seconds to routes belonging to specified address families; routes of other address families continue to be advertised according to the session-level MRAI setting.
The no form of this command disables rapid update for all address families.
Default
no rapid-update
Parameters
- l2-vpn
Keyword to enable the BGP rapid update for the 12-byte Virtual Switch Instance identifier (VSI-ID) value, which consists of the 8-byte route distinguisher (RD) followed by a 4-byte value.
- mvpn-ipv4
Keyword to enable the BGP rapid update for the MVPN-IPv4 address family. The MVPN-IPv4 address is a variable size value consisting of the 1-byte route type, 1-byte length, and variable size that is route type specific. Route type defines encoding for the route type specific field. Length indicates the length in octets of the route type specific field.
This keyword is supported only on the 7210 SAS-Mxp, 7210 SAS-R6, 7210 SAS-R12, 7210 SAS-Sx/S 1/10GE (standalone and standalone-VC), and 7210 SAS-T (network). This family is not supported for 7210 SAS-Sx 10/100GE devices.
- evpn
Keyword to enable the BGP rapid update for the EVPN address family by including EVPN routes from the set of routes that can trigger rapid update. This keyword is supported only on the 7210 SAS-Mxp, 7210 SAS-R6, and 7210 SAS-R12.
rapid-withdrawal
Syntax
[no] rapid-withdrawal
Context
config>router>bgp
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command disables the delay (Minimum Route Advertisement) on sending BGP withdrawals. Normal route withdrawals may be delayed up to the minimum route advertisement to allow for efficient packing of BGP updates.
The no form of this command removes this command from the configuration and reverts withdrawal processing to the normal behavior.
Default
no rapid-withdrawal
prefix-limit
Syntax
prefix-limit limit [log-only] [threshold percentage]
no prefix-limit
Context
config>router>bgp>group
config>router>bgp>group>neighbor
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command configures the maximum number of routes BGP can learn from a peer.
When the number of routes reaches 90% of this limit, an SNMP trap is sent. When the limit is exceeded, the BGP peering is dropped and disabled.
The no form of this command removes the configuration.
Default
no prefix-limit
Parameters
- limit
Specifies the number of routes that can be learned from a peer, expressed as a decimal integer.
- log-only
Keyword that enables the warning message to be sent at the specified threshold percentage, and also when the limit is exceeded. However, the BGP peering is not dropped.
- percentage
Specifies the threshold value (as a percentage) that triggers a warning message to be sent.
remove-private
Syntax
[no] remove-private [limited]
Context
config>router>bgp
config>router>bgp>group
config>router>bgp>group>neighbor
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command enables private ASNs to be removed from the AS path before advertising them to BGP peers.
When this command is set at the global level, it applies to all peers regardless of group or neighbor configuration. When the command is set at the group level, it applies to all peers in the group regardless of the neighbor configuration.
7210 SAS software recognizes the set of ASNs that are defined by IANA as private. These are ASNs in the range of 64512 through 65535, inclusive.
The no form of this command used at the global level reverts to the default value.
The no form of this command used at the group level reverts to the value defined at the global level.
The no form of this command used at the neighbor level reverts to the value defined at the group level.
Default
no remove-private
Parameters
- limited
Optional keyword that removes private ASNs up to the first public ASN encountered, at which point it stops removing private ASNs.
router-id
Syntax
router-id ip-address
no router-id
Context
config>router>bgp
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command specifies the router ID to be used with this BGP instance.
Changing the BGP router ID on an active BGP instance causes the BGP instance to restart with the new router ID. The router ID must be set to a valid host address. By default, no router ID is configured for BGP; the system interface IP address is used.
Parameters
- ip-address
Specifies the router ID, expressed in dotted decimal notation. Allowed value is a valid routable IP address on the router, either an interface or system IP address. Nokia highly recommends that this address be the system IP address.
shutdown
Syntax
[no] shutdown
Context
config>router>bgp
config>router>bgp>group
config>router>bgp>group>neighbor
Platforms
Supported on all 7210 SAS platforms as described in this document
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 may be deleted.
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 administrative states for services and service entities are described in Special Cases.
The no form of this command places an entity in an administratively enabled state.
Special Cases
- BGP Protocol Handling
On all 7210 SAS platforms, BGP is created in the no shutdown state.
On the 7210 SAS-Mxp, the protocol is handled as follows.
The configure router bgp command instantiates the protocol in the no shutdown state, and resources are allocated to enable the node to process the protocol.
To deallocate resources, issue the configure router bgp shutdown and configure router no bgp commands to allow the node to boot up correctly after the reboot. It is not sufficient to only issue a configure router bgp shutdown command.
The resources for BGP are allocated when the BGP context is enabled either in the base routing instance or the VPRN service instance. Resources are deallocated when the configuration of the last BGP context under either base routing instances or VPRN service is removed or shut down.
- BGP Global
The BGP protocol is created in the no shutdown state on all 7210 SAS platforms.
- BGP Group
BGP groups are created in the no shutdown state.
- BGP Neighbor
BGP neighbors/peers are created in the no shutdown state.
type
Syntax
[no] type {internal | external}
Context
config>router>bgp>group
config>router>bgp>group>neighbor
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command designates the BGP peer as type internal or external.
Specifying the internal parameter type indicates the peer is an iBGP peer; specifying the external parameter type indicates the peer is an eBGP peer.
By default, 7210 SAS derives the type of neighbor based on the local AS specified. If the local AS specified is the same as the AS of the router, the peer is considered internal. If the local AS is different, the peer is considered external.
The no form of this command used at the group level reverts to the default value.
The no form of this command used at the neighbor level reverts to the value defined at the group level.
Default
no type
Parameters
- internal
Keyword that configures the peer as internal.
- external
Keyword that configures the peer as external.
Other BGP-related commands
autonomous-system
Syntax
autonomous-system autonomous-system
no autonomous-system
Context
config>router
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command configures the autonomous system number (ASN) for the router. A router can only belong to one AS. An ASN is a globally unique number with an AS. This number is used to exchange exterior routing information with neighboring ASs and as an identifier of the AS.
If the ASN is changed on a router with an active BGP instance, the new AS number is not used until the BGP instance is restarted either by administratively disabling and enabling (shutdown or no shutdown) the BGP instance or rebooting the system with the new configuration.
Parameters
- as-number
Specifies the AS number, expressed as a decimal integer.
router-id
Syntax
router-id ip-address
no router-id
Context
config>router
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command configures the router ID for the router instance.
The router ID is used by both OSPF and BGP routing protocols in this instance of the routing table manager.
When configuring a new router ID, protocols are not automatically restarted with the new router ID. The next time a protocol is initialized, the new router ID is used. This can result in an interim period of time when different protocols use different router IDs.
To force the new router ID to be used, issue the shutdown and no shutdown commands for each protocol that uses the router ID, or restart the entire router.
By default, the system uses the system interface address (which is also the loopback address). If a system interface address is not configured, use the last 32 bits of the chassis MAC address.
The no form of this command to reverts to the default value.
Parameters
- ip-address
Specifies the 32-bit router ID, expressed in dotted decimal notation or as a decimal value.
Show commands
router
Syntax
router [router-instance]
Context
show
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command displays router instance information.
Parameters
- router-instance
Specifies either the router name or service ID.
bgp
Syntax
bgp
Context
show>router
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
Commands in this context display BGP-related information.
auth-keychain
Syntax
auth-keychain [keychain]
Context
show>router>bgp
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command displays BGP sessions using a particular authentication keychain.
Parameters
- keychain
Specifies an existing keychain name, up to 32 characters.
Output
The following outputs are examples of BGP authentication keychain information, and Output fields: BGP PIC describes the output fields.
Sample output*A:ALA-48# show router 2 bgp auth-keychain
===============================================================================
Sessions using key chains
===============================================================================
Peer address Group Keychain name
-------------------------------------------------------------------------------
10.20.1.3 1 eta_keychain1
10.1.0.2 1 eta_keychain1
===============================================================================
*A:ALA-48#
*A:ALA-48>config>router>bgp# show router bgp group "To_AS_10000"
===============================================================================
BGP Group : To_AS_10000
-------------------------------------------------------------------------------
Group : To_AS_10000
-------------------------------------------------------------------------------
Group Type : No Type State : Up
Peer AS : 10000 Local AS : 200
Local Address : n/a Loop Detect : Ignore
Import Policy : None Specified / Inherited
Hold Time : 90 Keep Alive : 30
Cluster Id : 0.0.0.100 Client Reflect : Enabled
NLRI : Unicast Preference : 170
TTL Security : Disabled Min TTL Value : n/a
Graceful Restart : Enabled Stale Routes Time: 360
Auth key chain : testname
List of Peers
- 10.0.0.8 :
To_Router B - EBGP Peer
Total Peers : 1 Established : 0
-------------------------------------------------------------------------------
Peer Groups : 1
===============================================================================
*A:ALA-48>config>router>bgp#
Sample output: BGP PIC
*A:7210SAS>show>service>id# show service id 1 base
===============================================================================
Service Basic Information
===============================================================================
Service Id : 1 Vpn Id : 0
Service Type : VPRN
Name : (Not Specified)
Description : Default Description For VPRN ID 1
Customer Id : 1
Last Status Change: 01/08/2000 22:57:35
Last Mgmt Change : 01/08/2000 22:57:35
Admin State : Up Oper State : Up
Route Dist. : 100:1 VPRN Type : regular
AS Number : 100 Router Id : 10.1.1.1
ECMP : Enabled ECMP Max Routes : 1
Max IPv4 Routes : No Limit Auto Bind : MPLS
Max IPv6 Routes : No Limit
Ignore NH Metric : Disabled
Hash Label : Disabled
Vrf Target : target:200:1
Vrf Import : None
Vrf Export : None
MVPN Vrf Target : None
MVPN Vrf Import : None
MVPN Vrf Export : None
Label mode : vrf
BGP VPN Backup : ipv4 ipv6
SAP Count : 1 SDP Bind Count : 3
-------------------------------------------------------------------------------
Service Access & Destination Points
-------------------------------------------------------------------------------
Identifier Type AdmMTU OprMTU Adm Opr
-------------------------------------------------------------------------------
sap:1/1/2:1 q-tag 9212 9212 Up Up
sdp:1002:1 S(2.2.2.2) Spok 0 9186 Up Up
sdp:1003:1 S(3.3.3.3) Spok 0 9186 Up Up
sdp:1004:1 S(4.4.4.4) Spok 0 9186 Up Up
===============================================================================
*A:7210SAS>show>service>id#
Label |
Description |
---|---|
Service Id |
Displays the service ID |
VPN Id |
Displays the VPN ID |
Service Type |
Displays the service type |
Name |
Displays the service name |
Description |
Displays the description of the service |
Customer Id |
Displays the customer ID |
Last Status Change |
Displays the date and time of the most recent change in the administrative or operating status of the service |
Last Mgmt Change |
Displays the date and time of the most recent management-initiated change to this service |
Admin State |
Displays the required state of the service |
Oper State |
Displays the current operational state of the service |
Route Dist. |
Displays the route distribution number |
VPRN Type |
Only valid in services that accept mesh SDP bindings It validates the VC ID portion of each mesh SDP binding defined in the service. |
AS Number |
Displays the autonomous system number |
Router Id |
Displays the router ID for this service |
ECMP Max Routes |
Displays the maximum number of routes that can be received from the neighbors in the group or for the specific neighbor |
ECMP |
Displays equal cost multipath information |
Max IPv4 Routes |
Displays the maximum number of IPv4 routes that can be used for path sharing |
Auto Bind |
Displays the automatic binding type for the SDP assigned to this service |
Max IPv6 Routes |
Displays the maximum number of IPv6 routes that can be used for path sharing |
Ignore NH Metric |
Indicates whether ignore NH metric is enabled or disabled |
Hash Label |
Indicates whether the hash label is enabled or disabled |
Vrf Target |
Displays the route target in the VRF applied to this service |
Vrf Import |
Displays the VRF import policy applied to this service |
Vrf Export |
Displays the VRF export policy applied to this service |
MVPN Vrf Target |
Displays the route target in the MVPN VRF applied to this service |
MVPN Vrf Import |
Displays the MVPN VRF import policy applied to this service |
MVPN Vrf Export |
Displays the MVPN VRF export policy applied to this service |
Label mode |
Displays the label mode |
BGP VPN Backup |
Indicates whether the BGP VPN backup is enabled or disabled |
SAP Count |
Displays the number of SAPs specified for this service |
SDP Bind Count |
Displays the number of SDPs bound to this service |
Service Access and Destination Points |
|
Identifier |
Displays the SAP or SDP identifier |
type |
Indicates whether this service SDP binding is a spoke or a mesh |
AdmMTU |
Displays the required largest service frame size (in octets) that can be transmitted through this SAP or SDP to the far-end router, without requiring the packet to be fragmented |
OprMTU |
Displays the actual largest service frame size (in octets) that can be transmitted through this SAP or SDP to the far-end router, without requiring the packet to be fragmented |
Adm |
Displays the administrative state of this SAP or SDP |
Opr |
Displays the operational state of this SAP or SDP |
damping
Syntax
damping [ip-prefix[/ip-prefix-length]] [damp-type] [detail]
Context
show>router>bgp
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command displays BGP routes that have been dampened because of route flapping. This command can be entered with or without a route parameter.
When the detail keyword is included, more detailed information displays.
When only the command is entered (without any parameters included except detail), all dampened routes are listed.
When a parameter is specified, the matching route or routes are listed.
When a decayed, history, or suppressed keyword is specified, only those types of dampened routes are listed.
Parameters
- ip-prefix/ip-prefix-length
Displays damping information for the specified IP prefix and length.
- damp-type
Specifies the type of damping to display.
- detail
Displays detailed information.
Output
The following outputs are examples of BGP damping information, and Output fields: BGP damping describes the output fields.
Sample outputA:ALA-12# show router bgp damping
===============================================================================
BGP Router ID : 10.0.0.14 AS : 65206 Local AS : 65206
===============================================================================
Legend -
Status codes : u - used, s - suppressed, h - history, d - decayed, * - valid
Origin codes : i - IGP, e - EGP, ? - incomplete, - best
===============================================================================
BGP Damped Routes
===============================================================================
Flag Network From Reuse AS-Path
-------------------------------------------------------------------------------
ud*i 10.149.7.0/24 10.0.28.1 00h00m00s 60203 65001 19855 3356
1239 22406
si 10.155.6.0/23 10.0.28.1 00h43m41s 60203 65001 19855 3356
2914 7459
si 10.155.8.0/22 10.0.28.1 00h38m31s 60203 65001 19855 3356
2914 7459
si 10.155.12.0/22 10.0.28.1 00h35m41s 60203 65001 19855 3356
2914 7459
si 10.155.22.0/23 10.0.28.1 00h35m41s 60203 65001 19855 3356
2914 7459
si 10.155.24.0/22 10.0.28.1 00h35m41s 60203 65001 19855 3356
2914 7459
si 10.155.28.0/22 10.0.28.1 00h34m31s 60203 65001 19855 3356
2914 7459
si 10.155.40.0/21 10.0.28.1 00h28m24s 60203 65001 19855 3356
7911 7459
si 10.155.48.0/20 10.0.28.1 00h28m24s 60203 65001 19855 3356
7911 7459
ud*i 10.8.140.0/24 10.0.28.1 00h00m00s 60203 65001 19855 3356
4637 17447
ud*i 10.8.141.0/24 10.0.28.1 00h00m00s 60203 65001 19855 3356
4637 17447
ud*i 10.9.0.0/18 10.0.28.1 00h00m00s 60203 65001 19855 3356
3561 9658 6163
. . .
ud*i 10.213.184.0/23 10.0.28.1 00h00m00s 60203 65001 19855 3356
6774 6774 9154
-------------------------------------------------------------------------------
A:ALA-12#
A:ALA-12# show router bgp damping detail
===============================================================================
BGP Router ID : 10.0.0.14 AS : 65206 Local AS : 65206
===============================================================================
Legend -
Status codes : u - used, s - suppressed, h - history, d - decayed, * -
valid
Origin codes : i - IGP, e - EGP, ? - incomplete, - best
===============================================================================
BGP Damped Routes
===============================================================================
-------------------------------------------------------------------------------
Network : 10.149.7.0/24
-------------------------------------------------------------------------------
Network : 10.149.7.0/24 Peer : 10.0.28.1
NextHop : 10.0.28.1 Reuse time : 00h00m00s
Peer AS : 60203 Peer Router-Id : 10.32.27.203
Local Pref : none
Age : 00h22m09s Last update : 02d00h58m
FOM Present : 738 FOM Last upd. : 2039
Number of Flaps : 2 Flags : ud*i
Path : 60203 65001 19855 3356 1239 22406
Applied Policy : default-damping-profile
-------------------------------------------------------------------------------
Network : 10.142.48.0/20
-------------------------------------------------------------------------------
Network : 10.142.48.0/20 Peer : 10.0.28.1
NextHop : 10.0.28.1 Reuse time : 00h00m00s
Peer AS : 60203 Peer Router-Id : 10.32.27.203
Local Pref : none
Age : 00h00m38s Last update : 02d01h20m
FOM Present : 2011 FOM Last upd. : 2023
Number of Flaps : 2 Flags : ud*i
Path : 60203 65001 19855 3356 3561 5551 1889
Applied Policy : default-damping-profile
-------------------------------------------------------------------------------
Network : 10.200.128.0/19
-------------------------------------------------------------------------------
Network : 10.200.128.0/19 Peer : 10.0.28.1
NextHop : 10.0.28.1 Reuse time : 00h00m00s
Peer AS : 60203 Peer Router-Id : 10.32.27.203
Local Pref : none
Age : 00h00m38s Last update : 02d01h20m
FOM Present : 2011 FOM Last upd. : 2023
Number of Flaps : 2 Flags : ud*i
Path : 60203 65001 19855 1299 702 1889
Applied Policy : default-damping-profile
-------------------------------------------------------------------------------
Network : 15.203.192.0/18
-------------------------------------------------------------------------------
Network : 10.203.192.0/18 Peer : 10.0.28.1
NextHop : 10.0.28.1 Reuse time : 00h00m00s
Peer AS : 60203 Peer Router-Id : 10.32.27.203
Local Pref : none
Age : 00h00m07s Last update : 02d01h20m
FOM Present : 1018 FOM Last upd. : 1024
Number of Flaps : 1 Flags : ud*i
Path : 60203 65001 19855 1299 702 1889
Applied Policy : default-damping-profile
-------------------------------------------------------------------------------
A:ALA-12#
A:ALA-12# show router bgp damping 15.203.192.0/18 detail
===============================================================================
BGP Router ID : 10.0.0.14 AS : 65206 Local AS : 65206
===============================================================================
Legend -
Status codes : u - used, s - suppressed, h - history, d - decayed, * - valid
Origin codes : i - IGP, e - EGP, ? - incomplete, - best
===============================================================================
BGP Damped Routes 10.203.192.0/18
===============================================================================
-------------------------------------------------------------------------------
Network : 10.203.192.0/18
-------------------------------------------------------------------------------
Network : 10.203.192.0/18 Peer : 10.0.28.1
NextHop : 10.0.28.1 Reuse time : 00h00m00s
Peer AS : 60203 Peer Router-Id : 10.32.27.203
Local Pref : none
Age : 00h00m42s Last update : 02d01h20m
FOM Present : 2003 FOM Last upd. : 2025
Number of Flaps : 2 Flags : ud*i
Path : 60203 65001 19855 3356 702 1889
Applied Policy : default-damping-profile
-------------------------------------------------------------------------------
Paths : 1
===============================================================================
A:ALA-12#
A:ALA-12# show router bgp damping suppressed detail
===============================================================================
BGP Router ID : 10.0.0.14 AS : 65206 Local AS : 65206
===============================================================================
Legend -
Status codes : u - used, s - suppressed, h - history, d - decayed, * - valid
Origin codes : i - IGP, e - EGP, ? - incomplete, - best
===============================================================================
BGP Damped Routes (Suppressed)
===============================================================================
-------------------------------------------------------------------------------
Network : 10.142.48.0/20
-------------------------------------------------------------------------------
Network : 10.142.48.0/20 Peer : 10.0.28.1
NextHop : 10.0.28.1 Reuse time : 00h29m22s
Peer AS : 60203 Peer Router-Id : 10.32.27.203
Local Pref : none
Age : 00h01m28s Last update : 02d01h20m
FOM Present : 2936 FOM Last upd. : 3001
Number of Flaps : 3 Flags : si
Path : 60203 65001 19855 3356 702 1889
Applied Policy : default-damping-profile
-------------------------------------------------------------------------------
Network : 10.200.128.0/19
-------------------------------------------------------------------------------
Network : 10.200.128.0/19 Peer : 10.0.28.1
NextHop : 10.0.28.1 Reuse time : 00h29m22s
Peer AS : 60203 Peer Router-Id : 10.32.27.203
Local Pref : none
Age : 00h01m28s Last update : 02d01h20m
FOM Present : 2936 FOM Last upd. : 3001
Number of Flaps : 3 Flags : si
Path : 60203 65001 19855 3356 702 1889
Applied Policy : default-damping-profile
-------------------------------------------------------------------------------
Network : 10.203.240.0/20
-------------------------------------------------------------------------------
Network : 10.203.240.0/20 Peer : 10.0.28.1
NextHop : 10.0.28.1 Reuse time : 00h29m22s
Peer AS : 60203 Peer Router-Id : 10.32.27.203
Local Pref : none
Age : 00h01m28s Last update : 02d01h20m
FOM Present : 2936 FOM Last upd. : 3001
Number of Flaps : 3 Flags : si
Path : 60203 65001 19855 3356 702 1889
Applied Policy : default-damping-profile
-------------------------------------------------------------------------------
Network : 10.206.0.0/17
-------------------------------------------------------------------------------
Network : 10.206.0.0/17 Peer : 10.0.28.1
NextHop : 10.0.28.1 Reuse time : 00h29m22s
Peer AS : 60203 Peer Router-Id : 10.32.27.203
Local Pref : none
Age : 00h01m28s Last update : 02d01h20m
FOM Present : 2936 FOM Last upd. : 3001
Number of Flaps : 3 Flags : si
Path : 60203 65001 19855 3356 702 1889
Applied Policy : default-damping-profile
-------------------------------------------------------------------------------
A:ALA-12#
Label |
Description |
---|---|
BGP Router ID |
Displays the local BGP router ID |
Local AS |
Displays the configured autonomous system number |
Network |
Displays the route IP prefix and mask length for the route |
Flags |
Legend: Status codes: u- used, s-suppressed, h-history, d-decayed, *-valid. If a ‟*” is not present, the status is invalid. Origin codes: i-IGP, e-EGP, ?-incomplete, >-best |
From |
Displays the originator ID path attribute value |
Reuse time |
Displays the time when a suppressed route can be used again |
From |
Displays the originator ID path attribute value |
Reuse time |
Displays the time when a suppressed route can be used again |
AS Path |
Displays the BGP AS path for the route |
Peer |
Displays the router ID of the advertising router |
NextHop |
Displays the BGP next hop for the route |
Peer AS |
Displays the autonomous system number of the advertising router |
Peer Router-Id |
Displays the router ID of the advertising router |
Local Pref |
Displays the BGP local preference path attribute for the route |
Age |
Displays the length of time in hour/minute/second (HH:MM:SS) format |
Last update |
Displays the time when BGP was updated last in day/hour/minute (DD:HH:MM) format |
FOM Present |
Displays the current Figure of Merit (FOM) value |
Number of Flaps |
Displays the number of route flaps in the neighbor connection |
Reuse time |
Displays the time when the route can be reused |
Path |
Displays the BGP AS path for the route |
Applied Policy |
Displays the applied route policy name |
group
Syntax
group [name] [detail]
Context
show>router>bgp
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command displays group information for a BGP peer group. This command can be entered with or without parameters.
When this command is entered without a group name, information about all peer groups displays.
When this command is issued with a specific group name, information pertaining only to that specific peer group displays.
The ‟State” field displays the BGP group operational state. Valid states are the following:
Up
The BGP global process is configured and running.
Down
The BGP global process is administratively shutdown and not running.
Disabled
The BGP global process is operationally disabled. The process must be restarted by the operator.
Parameters
- name
Displays information for the BGP group specified, up to 32 characters.
- detail
Displays detailed information.
Output
The following outputs are examples of BGP group information, and Output fields: BGP group describes the output fields.
Sample detailed outputA:ALA-12# show router bgp group detail
===============================================================================
BGP Groups (detail)
-------------------------------------------------------------------------------
Group : To_AS_40000
-------------------------------------------------------------------------------
Description : Not Available
Group Type : No Type State : Up
Peer AS : 40000 Local AS : 65206
Local Address : n/a Loop Detect : Ignore
Connect Retry : 20 Authentication : None
Local Pref : 100 MED Out : 0
Multihop : 0 (Default)
Min Route Advt. : 30 Min AS Originate : 15
Prefix Limit : No Limit Passive : Disabled
Next Hop Self : Disabled Aggregator ID 0 : Disabled
Remove Private : Disabled Damping : Disabled
Export Policy : direct2bgp
Hold Time : 90 Keep Alive : 30
Cluster Id : None Client Reflect : Enabled
NLRI : Unicast Preference : 170
List of Peers
- 10.0.0.1 : To_Jukebox
- 10.0.0.12 : Not Available
- 10.0.0.13 : Not Available
- 10.0.0.14 : To_SR1
- 10.0.0.15 : To_H-215
Total Peers : 5 Established : 2
===============================================================================
A:ALA-12#
A:SetupCLI>show>router>bgp# group
===============================================================================
BGP Group
-------------------------------------------------------------------------------
Group : bgp_group_1 34567890123456789012
-------------------------------------------------------------------------------
Description : Testing the length of the group value for the DESCRIPTION
parameter of BGP
Group Type : No Type State : Up
Peer AS : n/a Local AS : 100
Local Address : n/a Loop Detect : Ignore
Import Policy : test i1
: test i2
: test i3
: test i4
: test i5 890123456789012345678901
Export Policy : test e1
: test e2
: test e3
: test e4
: test e5 890123456789012345678901
Hold Time : 120 Keep Alive : 30
Cluster Id : None Client Reflect : Disabled
NLRI : Unicast Preference : 101
TTL Security : Disabled Min TTL Value : n/a
Graceful Restart : Disabled Stale Routes Time: n/a
Auth key chain : n/a Bfd Enabled : Yes
List of Peers
- 3.3.3.3 :
Testing the length of the neighbor value for the DESCRIPTION parameter of
BGP
Total Peers : 1 Established : 0
-------------------------------------------------------------------------------
Peer Groups : 1
===============================================================================
A:SetupCLI>show>router>bgp#
Sample output
A:ALA-12# show router bgp group
===============================================================================
BGP Groups
-------------------------------------------------------------------------------
Group : To_AS_40000
-------------------------------------------------------------------------------
Description : Not Available
Group Type : No Type State : Up
Peer AS : 40000 Local AS : 65206
Local Address : n/a Loop Detect : Ignore
Export Policy : direct2bgp
Hold Time : 90 Keep Alive : 30
Cluster Id : None Client Reflect : Enabled
NLRI : Unicast Preference : 170
List of Peers
- 10.0.0.1 : To_Jukebox
- 10.0.0.12 : Not Available
- 10.0.0.13 : Not Available
- 10.0.0.14 : To_SR1
- 10.0.0.15 : To_H-215
Total Peers : 5 Established : 2
===============================================================================
A:ALA-12#
Label |
Description |
---|---|
Group |
Displays the BGP group name |
Group Type |
No Type — peer type not configured External — peer type configured as external BGP peers Internal — peer type configured as internal BGP peers |
State |
Disabled — the BGP peer group has been operationally disabled Down — the BGP peer group is operationally inactive
|
Peer AS |
Displays the configured or inherited peer AS for the specified peer group |
Local AS |
Displays the configured or inherited local AS for the specified peer group |
Local Address |
Displays the configured or inherited local address for originating peering for the specified peer group |
Loop Detect |
Displays the configured or inherited loop detect setting for the specified peer group |
Connect Retry |
Displays the configured or inherited connect retry timer value |
Authentication |
None — no authentication is configured MD5 — MD5 authentication is configured |
Bfd |
Yes — BFD is enabled No — BFD is disabled |
Local Pref |
Displays the configured or inherited local preference value |
MED Out |
Displays the configured or inherited MED value assigned to advertised routes without a MED attribute |
Min Route Advt. |
Displays the minimum amount of time that must pass between route updates for the same IP prefix |
Min AS Originate |
Displays the minimum amount of time that must pass between updates for a route originated by the local router |
Multihop |
Displays the maximum number of router hops a BGP connection can traverse |
Prefix Limit |
No Limit — no route limit assigned to the BGP peer group 1 to 4294967295 — yhe maximum number of routes BGP can learn from a peer |
Passive |
Disabled — BGP attempts to establish a BGP connection with neighbor in the specified peer group Enabled — BGP will not actively attempt to establish a BGP connection with neighbor in the specified peer group |
Next Hop Self |
Disabled — BGP is not configured to send only its own IP address as the BGP next hop in route updates to neighbors in the peer group Enabled — BGP sends only its own IP address as the BGP next hop in route updates to neighbors in the specified peer group |
Aggregator ID 0 |
Disabled — BGP is not configured to set the aggregator ID to 0.0.0.0 in all originated route aggregates sent to the neighbor in the peer group Enabled — BGP is configured to set the aggregator ID to 0.0.0.0 in all originated route aggregates sent to the neighbor in the peer group |
Remove Private |
Disabled — BGP will not remove all private ASNs from the AS path attribute in updates sent to the neighbor in the peer group Enabled — BGP removes all private ASNs from the AS path attribute in updates sent to the neighbor in the peer group |
Damping |
Disabled — the peer group is configured not to dampen route flaps Enabled — the peer group is configured to dampen route flaps |
Export Policy |
Displays the configured export policies for the peer group |
Import Policy |
Displays the configured import policies for the peer group |
Hold Time |
Displays the configured hold-time setting |
Keep Alive |
Displays the configured keepalive setting |
Cluster Id |
Displays the configured route reflector cluster ID None — no cluster ID has been configured |
Client Reflect |
Disabled — the BGP route reflector does not reflect routes to this neighbor Enabled — the BGP route reflector is configured to reflect routes to this neighbor |
NLRI |
Displays the type of NLRI information that the specified peer group can accept Unicast — IPv4 unicast routing information can be carried |
Preference |
Displays the configured route preference value for the peer group |
List of Peers |
Displays a list of BGP peers configured under the peer group |
Total Peers |
Displays the total number of peers configured under the peer group |
Established |
Displays the total number of peers that are in an established state |
neighbor
Syntax
neighbor [ip-address [detail]]
neighbor [as-address [detail]]
neighbor [as-number [detail] filter2]
neighbor ip-address [family [type mvpn-type]] filter1 [brief]
neighbor ip-number [family] filter2
neighbor as-number [family] filter2
neighbor ip-address orf [filter3]
neighbor ip-address graceful-restart
Context
show>router>bgp
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command displays BGP neighbor information. This command can be entered with or without parameters.
When this command is issued without any parameters, information about all BGP peers displays.
When the command is issued with a specific IP address or ASN, information about only that specific peer or peers with the same AS displays.
When either received-routes or advertised-routes is specified, the routes received from or sent to the specified peer is listed (see second output example).
This information is not available when using SNMP.
When either history or suppressed is specified, the routes learned from those peers that either have a history or are suppressed (respectively) are listed.
The ‟State” field displays the BGP peer protocol state. In addition to the standard protocol states, this field can also display the ‟Disabled” operational state, which indicates the peer is operationally disabled and must be restarted.
Parameters
- ip-address
Displays information for the specified IP address.
- as-number
Displays information for the specified ASN.
- family
Specifies the type of routing information to be distributed by this peer group.
- filter1
Displays information for the specified IP address.
- filter2
Displays information for the specified ASN.
- brief
Displays information in a brief format. This parameter is only supported with received routes and advertised routes.
- orf
Displays Outbound Route Filtering (ORF) for the BGP instance. ORF is used to inform a neighbor of targets (using target-list) that it is willing to receive. This mechanism helps lessen the update exchanges between neighbors and saves CPU cycles to process routes that could have been received from the neighbor only to be dropped or ignored.
- filter3
Displays path information for the specified IP address.
- graceful-restart
Displays neighbors configured for graceful restart.
Output
The following outputs are example of BGP neighbor information. The associated tables describe the output fields.
-
Sample output, Sample output — detailed, Output fields: BGP neighbor
-
Sample output — received routes, Output fields: BGP neighbor received routes
-
Sample output — add-path, Output fields: show neighbor add-path
*A:7210-SAS>show>router>bgp# neighbor
===============================================================================
BGP Neighbor
===============================================================================
-------------------------------------------------------------------------------
Peer : 10.1.1.1
Group : sample
-------------------------------------------------------------------------------
Peer AS : 12345 Peer Port : 0
Peer Address : 10.1.1.1
Local AS : 143 Local Port : 0
Local Address : 0.0.0.0
Peer Type : External
State : Active Last State : Connect
Last Event : openFail
Last Error : Cease
Local Family : IPv4 VPN-IPv4
Remote Family : Unused
Hold Time : 10000 (strict) Keep Alive : 21845
Active Hold Time : 0 Active Keep Alive : 0
Cluster Id : None
Preference : 10 Num of Flaps : 0
Recd. Paths : 0
IPv4 Recd. Prefixes : 0 IPv4 Active Prefixes : 0
IPv4 Suppressed Pfxs : 0 VPN-IPv4 Suppr. Pfxs : 0
VPN-IPv4 Recd. Pfxs : 0 VPN-IPv4 Active Pfxs : 0
Mc IPv4 Recd. Pfxs. : 0 Mc IPv4 Active Pfxs. : 0
Mc IPv4 Suppr. Pfxs : 0 IPv6 Suppressed Pfxs : 0
IPv6 Recd. Prefixes : 0 IPv6 Active Prefixes : 0
VPN-IPv6 Recd. Pfxs : 0 VPN-IPv6 Active Pfxs : 0
VPN-IPv6 Suppr. Pfxs : 0
MVPN-IPv4 Suppr. Pfxs: 0 MVPN-IPv4 Recd. Pfxs : 0
MVPN-IPv4 Active Pfxs: 0
Input Queue : 0 Output Queue : 0
i/p Messages : 0 o/p Messages : 1
i/p Octets : 0 o/p Octets : 0
i/p Updates : 0 o/p Updates : 0
TTL Security : Disabled Min TTL Value : n/a
Graceful Restart : Enabled Stale Routes Time : 3600
Advertise Inactive : Enabled Peer Tracking : Enabled
Advertise Label : None
Auth key chain : keychain-one
Bfd Enabled : Disabled L2 VPN Cisco Interop : Disabled
Local Capability : RtRefresh MPBGP ORFSendExComm ORFRecvExComm
Remote Capability :
Import Policy : abcd
Export Policy : abcd
-------------------------------------------------------------------------------
Peer : 10.1.3.4
Group : test
-------------------------------------------------------------------------------
Peer AS : 0 Peer Port : 0
Peer Address : 10.1.3.4
Local AS : 12345 Local Port : 0
Local Address : 0.0.0.0
Peer Type : External
State : Idle Last State : Idle
Last Event : none
Last Error : Unrecognized Error
Local Family : VPN-IPv4
Remote Family : Unused
Hold Time : 0 (strict) Keep Alive : 0
Active Hold Time : 0 Active Keep Alive : 0
Cluster Id : None
Preference : 10 Num of Flaps : 0
Recd. Paths : 0
IPv4 Recd. Prefixes : 0 IPv4 Active Prefixes : 0
IPv4 Suppressed Pfxs : 0 VPN-IPv4 Suppr. Pfxs : 0
VPN-IPv4 Recd. Pfxs : 0 VPN-IPv4 Active Pfxs : 0
Mc IPv4 Recd. Pfxs. : 0 Mc IPv4 Active Pfxs. : 0
Mc IPv4 Suppr. Pfxs : 0 IPv6 Suppressed Pfxs : 0
IPv6 Recd. Prefixes : 0 IPv6 Active Prefixes : 0
VPN-IPv6 Recd. Pfxs : 0 VPN-IPv6 Active Pfxs : 0
VPN-IPv6 Suppr. Pfxs : 0
MVPN-IPv4 Suppr. Pfxs: 0 MVPN-IPv4 Recd. Pfxs : 0
MVPN-IPv4 Active Pfxs: 0
Input Queue : 0 Output Queue : 0
i/p Messages : 0 o/p Messages : 0
i/p Octets : 0 o/p Octets : 0
i/p Updates : 0 o/p Updates : 0
TTL Security : Disabled Min TTL Value : n/a
Graceful Restart : Enabled Stale Routes Time : 100
Advertise Inactive : Enabled Peer Tracking : Enabled
Advertise Label : None
Auth key chain : n/a
Bfd Enabled : Enabled L2 VPN Cisco Interop : Disabled
Local Capability : RtRefresh MPBGP
Remote Capability :
Import Policy : abcd
Export Policy : abcd
-------------------------------------------------------------------------------
*A:7210-SAS>
*A:Dut-B>config>service# show router bgp neighbor
===============================================================================
BGP Neighbor
===============================================================================
-------------------------------------------------------------------------------
Peer : 10.20.1.3
Description : (Not Specified)
Group : PEER_TO_C
-------------------------------------------------------------------------------
Peer AS : 300 Peer Port : 179
Peer Address : 10.20.1.3
Local AS : 300 Local Port : 49635
Local Address : 10.20.1.5
Peer Type : Internal
State : Established Last State : Active
Last Event : recvKeepAlive
Last Error : Cease (Other Configuration Change)
Local Family : IPv4
Remote Family : IPv4
Hold Time : 90 Keep Alive : 30
Min Hold Time : 0
Active Hold Time : 90 Active Keep Alive : 30
Cluster Id : None
Preference : 170 Num of Update Flaps : 20
Recd. Paths : 5
IPv4 Recd. Prefixes : 10 IPv4 Active Prefixes : 10
IPv4 Suppressed Pfxs : 0 VPN-IPv4 Suppr. Pfxs : 0
VPN-IPv4 Recd. Pfxs : 0 VPN-IPv4 Active Pfxs : 0
Mc IPv4 Recd. Pfxs. : 0 Mc IPv4 Active Pfxs. : 0
Mc IPv4 Suppr. Pfxs : 0 IPv6 Suppressed Pfxs : 0
IPv6 Recd. Prefixes : 0 IPv6 Active Prefixes : 0
VPN-IPv6 Recd. Pfxs : 0 VPN-IPv6 Active Pfxs : 0
VPN-IPv6 Suppr. Pfxs : 0
Mc IPv6 Recd. Pfxs. : 0 Mc IPv6 Active Pfxs. : 0
Mc IPv6 Suppr. Pfxs : 0 L2-VPN Suppr. Pfxs : 0
L2-VPN Recd. Pfxs : 0 L2-VPN Active Pfxs : 0
MVPN-IPv4 Suppr. Pfxs: 0 MVPN-IPv4 Recd. Pfxs : 0
MVPN-IPv4 Active Pfxs: 0 MDT-SAFI Suppr. Pfxs : 0
MDT-SAFI Recd. Pfxs : 0 MDT-SAFI Active Pfxs : 0
Flow-IPv4 Suppr. Pfxs: 0 Flow-IPv4 Recd. Pfxs : 0
Flow-IPv4 Active Pfxs: 0 Rte-Tgt Suppr. Pfxs : 0
Rte-Tgt Recd. Pfxs : 0 Rte-Tgt Active Pfxs : 0
Backup IPv4 Pfxs : 0 Backup IPv6 Pfxs : 0
Mc Vpn Ipv4 Recd. Pf*: 0 Mc Vpn Ipv4 Active P*: 0
Mc Vpn Ipv4 Suppr. P*: 0
Backup Vpn IPv4 Pfxs : 0 Backup Vpn IPv6 Pfxs : 0
Input Queue : 0 Output Queue : 0
i/p Messages : 30 o/p Messages : 26
i/p Octets : 1321 o/p Octets : 470
i/p Updates : 8 o/p Updates : 0
Flow-IPv6 Suppr. Pfxs: 0 Flow-IPv6 Recd. Pfxs : 0
Flow-IPv6 Active Pfxs: 0
Evpn Suppr. Pfxs : 0 Evpn Recd. Pfxs : 0
Evpn Active Pfxs : 0
MS-PW Suppr. Pfxs : 0 MS-PW Recd. Pfxs : 0
MS-PW Active Pfxs : 0
TTL Security : Disabled Min TTL Value : n/a
Graceful Restart : Disabled Stale Routes Time : n/a
Restart Time : n/a
Advertise Inactive : Disabled Peer Tracking : Disabled
Advertise Label : ipv4
Auth key chain : n/a
Disable Cap Nego : Disabled Bfd Enabled : Disabled
Flowspec Validate : Disabled Default Route Tgt : Disabled
Aigp Metric : Enabled Split Horizon : Disabled
Damp Peer Oscillatio*: Disabled Update Errors : 0
GR Notification : Disabled Fault Tolerance : Disabled
Rem Idle Hold Time : 00h00m00s
Next-Hop Unchanged : None
L2 VPN Cisco Interop : Disabled
Local Capability : RtRefresh MPBGP 4byte ASN
Remote Capability : RtRefresh MPBGP 4byte ASN
Local AddPath Capabi*: Disabled
Remote AddPath Capab*: Send - None
: Receive - None
Import Policy : None Specified / Inherited
Export Policy : None Specified / Inherited
Origin Validation : N/A
EBGP Link Bandwidth : n/a
IPv4 Rej. Pfxs : 0 IPv6 Rej. Pfxs : 0
VPN-IPv4 Rej. Pfxs : 0 VPN-IPv6 Rej. Pfxs : 0
Mc IPv4 Rej. Pfxs : 0 Mc IPv6 Rej. Pfxs : 0
MVPN-IPv4 Rej. Pfxs : 0 MVPN-IPv6 Rej. Pfxs : 0
Flow-IPv4 Rej. Pfxs : 0 Flow-IPv6 Rej. Pfxs : 0
L2-VPN Rej. Pfxs : 0 MDT-SAFI Rej. Pfxs : 0
Rte-Tgt Rej. Pfxs : 0 MS-PW Rej. Pfxs : 0
Mc Vpn Ipv4 Rej. Pfxs: 0 Evpn Rej. Pfxs : 0
-------------------------------------------------------------------------------
Neighbors : 1
===============================================================================
* indicates that the corresponding row element may have been truncated.
*A:Dut-B>config>service#
A:ALA-48# show router 2 bgp neighbor 10.20.1.3
===============================================================================
BGP Neighbor
===============================================================================
Peer : 10.20.1.3
Group : 1
-------------------------------------------------------------------------------
Peer AS : 100 Peer Port : 49725
Peer Address : 10.20.1.3
Local AS : 100 Local Port : 179
Local Address : 10.20.1.2
Peer Type : Internal
State : Established Last State : Established
Last Event : recvKeepAlive
Last Error : Cease
Local Family : IPv4
Remote Family : IPv4
Hold Time : 3 Keep Alive : 1
Active Hold Time : 3 Active Keep Alive : 1
Cluster Id : None
Preference : 170 Num of Flaps : 0
Recd. Paths : 1
IPv4 Recd. Prefixes : 11 IPv4 Active Prefixes : 10
IPv4 Suppressed Pfxs : 0 VPN-IPv4 Suppr. Pfxs : 0
VPN-IPv4 Recd. Pfxs : 0 VPN-IPv4 Active Pfxs : 0
Mc IPv4 Recd. Pfxs. : 0 Mc IPv4 Active Pfxs. : 0
Mc IPv4 Suppr. Pfxs : 0
Input Queue : 0 Output Queue : 0
i/p Messages : 471 o/p Messages : 473
i/p Octets : 3241 o/p Octets : 3241
i/p Updates : 4 o/p Updates : 4
TTL Security : Disabled Min TTL Value : n/a
Advertise Inactive : Disabled Peer Tracking : Disabled
Advertise Label : None
Auth key chain : eta_keychain1
Local Capability : RouteRefresh MP-BGP
Remote Capability : RouteRefresh MP-BGP
Import Policy : None Specified / Inherited
Export Policy : static2bgp
-------------------------------------------------------------------------------
Neighbors : 1
===============================================================================
A:ALA-48#
A:ALA-12# show router bgp neighbor 10.0.0.11 orf
===============================================================================
BGP Neighbor 10.0.0.11 ORF
===============================================================================
Send List (Automatic)
-------------------------------------------------------------------------------
target:65535:10
target:65535:20
===============================================================================
A:ALA-12
A:ALA-22 show router bgp neighbor 10.0.0.1 orf
===============================================================================
BGP Neighbor 10.0.0.1 ORF
===============================================================================
Receive List
-------------------------------------------------------------------------------
target:65535:10
target:65535:20
===============================================================================
A:ALA-22
Sample output — detailed
A:ALA-12# show router bgp neighbor detail
===============================================================================
BGP Neighbor (detail)
-------------------------------------------------------------------------------
Peer : 10.0.0.15 Group : To_AS_40000
-------------------------------------------------------------------------------
Peer AS : 65205 Peer Port : 0
Peer Address : 10.0.0.15
Local AS : 65206 Local Port : 0
Local Address : 10.0.0.16
Peer Type : External
State : Active Last State : Connect
Last Event : openFail
Last Error : Hold Timer Expire
Connect Retry : 20 Local Pref. : 100
Min Route Advt. : 30 Min AS Orig. : 15
Damping : Disabled Loop Detect : Ignore
MED Out : No MED Out Authentication : None
Next Hop Self : Disabled AggregatorID Zero: Disabled
Remove Private : Disabled Passive : Disabled
Prefix Limit : No Limit
Hold Time : 90 Keep Alive : 30
Active Hold Time : 0 Active Keep Alive: 0
Cluster Id : None Client Reflect : Enabled
Preference : 170 Num of Flaps : 0
Recd. Prefixes : 0 Active Prefixes : 0
Recd. Paths : 0 Suppressed Paths : 0
Input Queue : 0 Output Queue : 0
i/p Messages : 0 o/p Messages : 0
i/p Octets : 0 o/p Octets : 0
i/p Updates : 0 o/p Updates : 0
Export Policy : direct2bgp
===============================================================================
A:ALA-12#
*A:SetupCLI>show>router>bgp# neighbor
===============================================================================
BGP Neighbor
===============================================================================
Peer : 10.3.3.3
Group : bgp_group_1 34567890123456789012
-------------------------------------------------------------------------------
Peer AS : 20 Peer Port : 0
Peer Address : 10.3.3.3
Local AS : 100 Local Port : 0
Local Address : 0.0.0.0
Peer Type : Internal
State : Active Last State : Idle
Last Event : stop
Last Error : Cease
Local Family : IPv4
Remote Family : Unused
Hold Time : 10 Keep Alive : 30
Active Hold Time : 0 Active Keep Alive : 0
Cluster Id : 2.2.3.4
Preference : 101 Num of Flaps : 0
Recd. Paths : 0
IPv4 Recd. Prefixes : 0 IPv4 Active Prefixes : 0
IPv4 Suppressed Pfxs : 0 VPN-IPv4 Suppr. Pfxs : 0
VPN-IPv4 Recd. Pfxs : 0 VPN-IPv4 Active Pfxs : 0
Mc IPv4 Recd. Pfxs. : 0 Mc IPv4 Active Pfxs. : 0
Mc IPv4 Suppr. Pfxs : 0
Input Queue : 0 Output Queue : 0
i/p Messages : 0 o/p Messages : 0
i/p Octets : 0 o/p Octets : 0
i/p Updates : 0 o/p Updates : 0
TTL Security : Disabled Min TTL Value : n/a
Graceful Restart : Enabled Stale Routes Time : 360
Advertise Inactive : Disabled Peer Tracking : Enabled
Advertise Label : None Bfd Enabled : Yes
Auth key chain : n/a
Local Capability : RouteRefresh MP-BGP
Remote Capability :
Import Policy : test i1
: test i2
: test i3
: test i4
: test i5 890123456789012345678901
Export Policy : test e1
: test e2
: test e3
: test e4
: test e5 890123456789012345678901
-------------------------------------------------------------------------------
Neighbors : 1
===============================================================================
Label |
Description |
---|---|
Peer |
Displays the IP address of the configured BGP peer |
Group |
Displays the BGP peer group to which this peer is assigned |
Peer AS |
Displays the configured or inherited peer AS for the peer group |
Peer Address |
Displays the configured address for the BGP peer |
Peer Port |
Displays the TCP port number used on the far-end system |
Local AS |
Displays the configured or inherited local AS for the peer group |
Local Address |
Displays the configured or inherited local address for originating peering for the peer group |
Local Port |
Displays the TCP port number used on the local system |
Peer Type |
External — peer type configured as external BGP peers Internal — peer type configured as internal BGP peers |
Bfd |
Yes — BFD is enabled No — BFD is disabled |
State |
Idle — the BGP peer is not accepting connections Active — BGP is listening for and accepting TCP connections from this peer Connect — BGP is attempting to establish a TCP connections from this peer Open Sent — BGP has sent an OPEN message to the peer and is waiting for an OPEN message from the peer Open Confirm — BGP has received a valid OPEN message from the peer and is awaiting a KEEPALIVE or NOTIFICATION Established — BGP has successfully established a peering and is exchanging routing information |
Last State |
Idle — the BGP peer is not accepting connections Active — BGP is listening for and accepting TCP connections from this peer Connect — BGP is attempting to establish a TCP connections from this peer Open Sent — BGP has sent an OPEN message to the peer and is waiting for an OPEN message from the peer Open Confirm — BGP has received a valid OPEN message from the peer and is awaiting a KEEPALIVE or NOTIFICATION |
Last Event |
start — BGP has initialized the BGP neighbor stop — BGP has disabled the BGP neighbor open — BGP transport connection opened close — BGP transport connection closed openFail — BGP transport connection failed to open error — BGP transport connection error connectRetry — connect retry timer expired holdTime — hold time timer expired keepAlive — keepalive timer expired recvOpen — receive an OPEN message revKeepalive — receive a KEEPALIVE message recvUpdate — receive an UPDATE message recvNotify — receive a NOTIFICATION message None — no events have occurred |
Last Error |
Displays the last BGP error and subcode to occur on the BGP neighbor |
Connect Retry |
Displays the configured or inherited connect retry timer value |
Local Pref. |
Displays the configured or inherited local preference value |
Min Route Advt. |
Displays the minimum amount of time that must pass between route updates for the same IP prefix |
Min AS Originate |
Displays the minimum amount of time that must pass between updates for a route originated by the local router |
Multihop |
Displays the maximum number of router hops a BGP connection can traverse. |
Damping |
|
Loop Detect |
Ignore — the BGP neighbor is configured to ignore routes with an AS loop Drop — the BGP neighbor is configured to drop the BGP peering if an AS loop is detected Off — AS loop detection is disabled for the neighbor |
MED Out |
Displays the configured or inherited MED value assigned to advertised routes without a MED attribute |
Authentication |
None — no authentication is configured MD5 — MD5 authentication is configured |
Next Hop Self |
Disabled — BGP is not configured to send only its own IP address as the BGP next hop in route updates to the specified neighbor Enabled — BGP sends only its own IP address as the BGP next hop in route updates to the neighbor |
AggregatorID Zero |
Disabled — the BGP neighbor is not configured to set the aggregator ID to 0.0.0.0 in all originated route aggregates Enabled — The BGP neighbor is configured to set the aggregator ID to 0.0.0.0 in all originated route aggregates |
Remove Private |
Disabled — BGP does not remove all private ASNs from the AS path attribute, in updates sent to the specified neighbor Enabled — BGP removes all private ASNs from the AS path attribute, in updates sent to the specified neighbor |
Passive |
Disabled — BGP actively attempts to establish a BGP connection with the specified neighbor Enabled — BGP does not actively attempt to establish a BGP connection with the specified neighbor |
Prefix Limit |
No Limit — no route limit assigned to the BGP peer group 1 to 4294967295 — the maximum number of routes BGP can learn from a peer |
Hold Time |
Displays the configured hold time setting |
Keep Alive |
Displays the configured keepalive setting |
Active Hold Time |
Displays the negotiated hold time, if the BGP neighbor is in an established state |
Active Keep Alive |
Displays the negotiated keepalive time, if the BGP neighbor is in an established state |
Cluster Id |
Displays the configured route reflector cluster ID
|
Client Reflect |
Disabled — the BGP route reflector is configured not to reflect routes to this neighbor Enabled — the BGP route reflector is configured to reflect routes to this neighbor |
Preference |
Displays the configured route preference value for the peer group |
Num of Flaps |
Displays the number of route flaps in the neighbor connection |
Recd. Prefixes |
Displays the number of routes received from the BGP neighbor |
Active Prefixes |
Displays the number of routes received from the BGP neighbor and active in the forwarding table |
Recd. Paths |
Displays the number of unique sets of path attributes received from the BGP neighbor |
Suppressed Paths |
Displays the number of unique sets of path attributes received from the BGP neighbor and suppressed as a result of route damping |
Input Queue |
Displays the number of BGP messages to be processed |
Output Queue |
Displays the number of BGP messages to be transmitted |
i/p Messages |
Displays total number of packets received from the BGP neighbor |
o/p Messages |
Displays the total number of packets sent to the BGP neighbor |
i/p Octets |
Displays the total number of octets received from the BGP neighbor |
o/p Octets |
Displays the total number of octets sent to the BGP neighbor |
Export Policy |
Displays the configured export policies for the peer group |
Import Policy |
Displays the configured import policies for the peer group |
A:ALA-12# show router bgp neighbor 10.0.0.16 received-routes
===============================================================================
BGP Router ID : 10.0.0.16 AS : 65206 Local AS : 65206
===============================================================================
Legend -
Status codes : u - used, s - suppressed, h - history, d - decayed, * - valid
Origin codes : i - IGP, e - EGP, ? - incomplete, > - best
===============================================================================
BGP IPv4 Routes
===============================================================================
Flag Network Nexthop LocalPref MED As-Path
-------------------------------------------------------------------------------
? 10.0.0.16/32 10.0.0.16 100 none No As-Path
? 10.0.6.0/24 10.0.0.16 100 none No As-Path
? 10.0.8.0/24 10.0.0.16 100 none No As-Path
? 10.0.12.0/24 10.0.0.16 100 none No As-Path
? 10.0.13.0/24 10.0.0.16 100 none No As-Path
? 10.0.204.0/24 10.0.0.16 100 none No As-Path
===============================================================================
A:ALA-12#
Label |
Description |
---|---|
BGP Router ID |
Displays the local BGP router ID |
AS |
Displays the configured autonomous system number |
Local AS |
Displays the configured local AS setting. If not configured, then it is the same value as the AS |
Flag |
u — used s — suppressed h — history d — decayed * — valid i — igp e — egp ? — incomplete > — best |
Network |
Displays the route IP prefix and mask length for the route |
Next Hop |
Displays the BGP next hop for the route |
LocalPref |
Displays the BGP local preference path attribute for the route |
MED |
Displays the BGP Multi-Exit Discriminator (MED) path attribute for the route |
AS Path |
Displays the BGP AS path for the route |
*A:7210SAS# show router bgp neighbor 10.2.2.2
===============================================================================
BGP Neighbor
===============================================================================
-------------------------------------------------------------------------------
Peer : 10.2.2.2
Group : toPE
-------------------------------------------------------------------------------
Peer AS : 100 Peer Port : 50854
Peer Address : 10.2.2.2
Local AS : 100 Local Port : 179
Local Address : 10.1.1.1
Peer Type : Internal
State : Established Last State : Established
Last Event : recvKeepAlive
Last Error : Cease (Connection Collision Resolution)
Local Family : IPv4 VPN-IPv4 IPv6 VPN-IPv6
Remote Family : IPv4 VPN-IPv4 IPv6 VPN-IPv6
Hold Time : 90 Keep Alive : 30
Min Hold Time : 0
Active Hold Time : 90 Active Keep Alive : 30
Cluster Id : None
Preference : 170 Num of Update Flaps : 0
Recd. Paths : 0
IPv4 Recd. Prefixes : 0 IPv4 Active Prefixes : 0
IPv4 Suppressed Pfxs : 0 VPN-IPv4 Suppr. Pfxs : 0
VPN-IPv4 Recd. Pfxs : 0 VPN-IPv4 Active Pfxs : 0
Mc IPv4 Recd. Pfxs. : 0 Mc IPv4 Active Pfxs. : 0
Mc IPv4 Suppr. Pfxs : 0 IPv6 Suppressed Pfxs : 0
IPv6 Recd. Prefixes : 0 IPv6 Active Prefixes : 0
VPN-IPv6 Recd. Pfxs : 0 VPN-IPv6 Active Pfxs : 0
VPN-IPv6 Suppr. Pfxs : 0 L2-VPN Suppr. Pfxs : 0
L2-VPN Recd. Pfxs : 0 L2-VPN Active Pfxs : 0
MVPN-IPv4 Suppr. Pfxs: 0 MVPN-IPv4 Recd. Pfxs : 0
MVPN-IPv4 Active Pfxs: 0 MDT-SAFI Suppr. Pfxs : 0
MDT-SAFI Recd. Pfxs : 0 MDT-SAFI Active Pfxs : 0
FLOW-IPV4-SAFI Suppr*: 0 FLOW-IPV4-SAFI Recd.*: 0
FLOW-IPV4-SAFI Activ*: 0 Rte-Tgt Suppr. Pfxs : 0
Rte-Tgt Recd. Pfxs : 0 Rte-Tgt Active Pfxs : 0
Backup IPv4 Pfxs : 0 Backup IPv6 Pfxs : 0
Mc Vpn Ipv4 Recd. Pf*: 0 Mc Vpn Ipv4 Active P*: 0
Backup Vpn IPv4 Pfxs : 0 Backup Vpn IPv6 Pfxs : 0
Input Queue : 0 Output Queue : 0
i/p Messages : 9042 o/p Messages : 65
i/p Octets : 111 o/p Octets : 278
i/p Updates : 0 o/p Updates : 0
TTL Security : Disabled Min TTL Value : n/a
Graceful Restart : Disabled Stale Routes Time : n/a
Advertise Inactive : Disabled Peer Tracking : Disabled
Advertise Label : ipv4 ipv6
Auth key chain : n/a
Disable Cap Nego : Disabled Bfd Enabled : Enabled
Flowspec Validate : Disabled Default Route Tgt : Disabled
L2 VPN Cisco Interop : Disabled
Local Capability : RtRefresh MPBGP 4byte ASN
Remote Capability : RtRefresh MPBGP 4byte ASN
Local AddPath Capabi*: Send - VPN-IPv4 (1) VPN-IPv6 (4)
: Receive - VPN-IPv6
Remote AddPath Capab*: Send - VPN-IPv6
: Receive - VPN-IPv4 VPN-IPv6
Import Policy : None Specified / Inherited
Export Policy : P1
-------------------------------------------------------------------------------
Neighbors : 1
===============================================================================
* indicates that the corresponding row element may have been truncated.
*A:7210SAS#
*A:ALA-48>config>router>bgp# show router bgp auth-keychain testname
=========================================================================
Sessions using key chain: keychain
=========================================================================
Peer address Group Keychain name
-------------------------------------------------------------------------
10.0.0.8 To_AS_10000 testname
=========================================================================
*A:ALA-48>config>router>bgp#
Label |
Description |
---|---|
Peer |
Displays the IP address of the configured BGP peer |
Group |
Displays the BGP peer group to which this peer is assigned |
Peer AS |
Displays the configured or inherited peer AS for the peer group |
Peer Address |
Displays the configured address for the BGP peer |
Peer Port |
Displays the TCP port number used on the far-end system |
Local AS |
Displays the configured or inherited local AS for the peer group |
Local Address |
Displays the configured or inherited local address for originating peering for the peer group |
Local Port |
Displays the TCP port number used on the local system |
Peer Type |
External — peer type configured as external BGP peers Internal — peer type configured as internal BGP peers |
State |
Idle — the BGP peer is not accepting connections (shut down) is also displayed if the peer is administratively disabled Active — BGP is listening for and accepting TCP connections from this peer Connect — BGP is attempting to establish a TCP connection with this peer Open Sent — BGP has sent an OPEN message to the peer and is waiting for an OPEN message from the peer Open Confirm — BGP has received a valid OPEN message from the peer and is awaiting a KEEPALIVE or NOTIFICATION Established — BGP has successfully established a peering session and is exchanging routing information |
Last State |
Idle — the BGP peer is not accepting connections Active — BGP is listening for and accepting TCP connections from this peer Connect — BGP is attempting to establish a TCP connections with this peer Open Sent — BGP has sent an OPEN message to the peer and is waiting for an OPEN message from the peer Open Confirm — BGP has received a valid OPEN message from the peer and is awaiting a KEEPALIVE or NOTIFICATION |
Last Event |
start — BGP has initialized the BGP neighbor stop — BGP has disabled the BGP neighbor open — BGP transport connection is opened close — BGP transport connection is closed openFail — BGP transport connection failed to open error — BGP transport connection error connectRetry — the connect retry timer expired holdTime — the hold time timer expired keepAlive — the keepalive timer expired recvOpen — BGP has received an OPEN message revKeepalive — BGP has received a KEEPALIVE message recvUpdate — BGP has received an UPDATE message recvNotify —BGP has received a NOTIFICATION message None — no events have occurred |
Last Error |
Displays the last BGP error and subcode to occur on the BGP neighbor |
Local Family |
Displays the configured local family value |
Remote Family |
Displays the configured remote family value |
Hold Time |
Displays the configured hold-time setting |
Keep Alive |
Displays the configured keepalive setting |
Min Hold Time |
Displays the configured minimum hold-time setting |
Active Hold Time |
Displays the negotiated hold time, if the BGP neighbor is in an established state |
Active Keep Alive |
Displays the negotiated keepalive time, if the BGP neighbor is in an established state |
Cluster Id |
Displays the configured route reflector cluster ID None — no cluster ID is configured |
Preference |
Displays the configured route preference value for the peer group |
Num of Flaps |
Displays the number of route flaps in the neighbor connection |
Recd. Prefixes |
Displays the number of routes received from the BGP neighbor |
Recd. Paths |
Displays the number of unique sets of path attributes received from the BGP neighbor |
IPv4 Recd. Prefixes |
Displays the number of unique sets of IPv4 path attributes received from the BGP neighbor |
IPv4 Active Prefixes |
Displays the number of IPv4 routes received from the BGP neighbor and active in the forwarding table |
IPv4 Suppressed Pfxs |
Displays the number of unique sets of IPv4 path attributes received from the BGP neighbor and suppressed because of route damping |
VPN-IPv4 Suppr. Pfxs |
Displays the number of unique sets of VPN-IPv4 path attributes received from the BGP neighbor and suppressed because of route damping |
VPN-IPv4 Recd. Pfxs |
Displays the number of unique sets of VPN-IPv4 path attributes received from the BGP neighbor |
VPN-IPv4 Active Pfxs |
Displays the number of VPN-IPv4 routes received from the BGP neighbor and active in the forwarding table |
IPv6 Recd. Prefixes |
Displays the number of unique sets of IPv6 path attributes received from the BGP neighbor |
IPv6 Active Prefixes |
Displays the number of IPv6 routes received from the BGP neighbor and active in the forwarding table |
VPN-IPv6 Recd. Pfxs |
Displays the number of unique sets of VPN-IPv6 path attributes received from the BGP neighbor |
VPN-IPv6 Active Pfxs |
Displays the number of VPN-IPv6 routes received from the BGP neighbor and active in the forwarding table |
VPN-IPv6 Suppr. Pfxs |
Displays the number of unique sets of VPN-IPv6 path attributes received from the BGP neighbor and suppressed as a result of route damping |
Backup IPv4 Pfxs |
Displays the number of BGP Fast Reroute backup path IPv4 prefixes |
Backup IPv6 Pfxs |
Displays the number of BGP Fast Reroute backup path IPv6 prefixes |
Backup Vpn IPv4 Pfxs |
Displays the number of BGP Fast Reroute backup path VPN IPv4 prefixes |
Backup Vpn IPv6 Pfxs |
Displays the number of BGP Fast Reroute backup path VPN IPv6 prefixes |
Input Queue |
Displays the number of BGP messages to be processed |
Output Queue |
Displays the number of BGP messages to be transmitted |
i/p Messages |
Displays the total number of packets received from the BGP neighbor |
o/p Messages |
Displays the total number of packets sent to the BGP neighbor |
i/p Octets |
Displays the total number of octets received from the BGP neighbor |
o/p Octets |
Displays the total number of octets sent to the BGP neighbor |
i/p Updates |
Displays the total number of updates received from the BGP neighbor |
o/p Updates |
Displays the total number of updates sent to the BGP neighbor |
TTL Security |
Enabled — TTL security is enabled Disabled — TTL security is disabled |
Min TTL Value |
Displays the minimum TTL value configured for the peer |
Graceful Restart |
Displays the state of graceful restart |
Stale Routes Time |
Displays the length of time that stale routes are kept in the route table |
Advertise Inactive |
Displays the state of advertising inactive BGP routes to other BGP peers (enabled or disabled) |
Peer Tracking |
Displays the state of tracking a neighbor IP address in the routing table for a BGP session |
Advertise Label |
Indicates the enabled address family for supporting RFC 3107 BGP label capability |
Auth key chain |
Displays the value for the authentication key chain |
Bfd Enabled |
Enabled — BFD is enabled Disabled — BFD is disabled |
Local Capability |
Displays the capability of the local BGP speaker; for example, route refresh, MP-BGP, ORF |
Remote Capability |
Displays the capability of the remote BGP peer; for example, route refresh, MP-BGP, ORF |
Local AddPath Capabi* |
Displays the state of the local BGP add-paths capabilities The add-paths capability allows the router to send and receive multiple paths per prefix to or from a peer. |
Remote AddPath Capab* |
Displays the state of the remote BGP add-paths capabilities |
Import Policy |
Displays the configured import policies for the peer group |
Export Policy |
Displays the configured export policies for the peer group |
next-hop
Syntax
next-hop [family] [ip-address] [detail]
Context
show>router>bgp
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command displays BGP next-hop information.
Parameters
- family
Specifies the type of routing information to be distributed by the BGP instance.
- ip-address
Displays the next-hop information for the specified IP address.
- detail
Displays a more detailed version of the output.
Output
The following output is an example of BGP next-hop information, and Output fields: BGP next-hop describes the output fields.
Sample output*A:Dut-C# show router bgp next-hop
===============================================================================
BGP Router ID:10.20.1.3 AS:5000 Local AS:5000
===============================================================================
===============================================================================
BGP Next Hop
===============================================================================
Next Hop Pref Owner
Resolving Prefix Metric
Resolved Next Hop Ref. Count
-------------------------------------------------------------------------------
10.20.1.1 7 RSVP
10.20.1.1/32 1000
10.10.2.1 2
10.20.1.2 7 RSVP
10.20.1.2/32 1000
10.10.3.2 2
10.20.1.4 7 RSVP
10.20.1.4/32 1000
10.10.11.4 2
-------------------------------------------------------------------------------
Next Hops : 3
A:ALA-49>show>router>bgp# next-hop 192.168.2.194
-------------------------------------------------------------------------------
BGP Router ID : 10.10.10.104 AS : 200 Local AS : 200
===============================================================================
BGP Next Hop
===============================================================================
Next Hop Resolving Owner Preference Reference Resolved
Prefix Count Next Hop
-------------------------------------------------------------------------------
A:ALA-49>show>router>bgp# next-hop 10.10.10.104
Label |
Description |
---|---|
BGP ID |
Displays the local BGP router ID |
AS |
Displays the configured autonomous system number |
Local AS |
Displays the configured local AS setting. If not configured, the value is the same as the AS. |
Next Hop |
Displays the next-hop address |
Resolving Prefix |
Displays the prefix of the best next hop |
Owner |
Displays the routing protocol used to derive the best next hop |
Preference |
Displays the BGP preference attribute for the routes |
Reference Count |
Displays the number of routes using the resolving prefix |
Resolved Next Hop |
Displays the IP address of the next hop |
paths
Syntax
paths
Context
show>router>bgp
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command displays a summary of BGP path attributes.
Output
The following output is an example of BGP path attribute information, and Output fields: BGP paths describes the output fields.
Sample output===============================================================================
BGP Router ID : 10.0.0.14 AS : 65206 Local AS : 65206
===============================================================================
BGP Paths
===============================================================================
Path: 60203 65001 19855 3356 15412
-------------------------------------------------------------------------------
Origin : IGP Next Hop : 10.0.28.1
MED : 60203 Local Preference : none
Refs : 4 ASes : 5
Segments : 1
Flags : EBGP-learned
Aggregator : 15412 62.216.140.1
-------------------------------------------------------------------------------
Path: 60203 65001 19855 3356 1 1236 1236 1236 1236
-------------------------------------------------------------------------------
Origin : IGP Next Hop : 10.0.28.1
MED : 60203 Local Preference : none
Refs : 2 ASes : 9
Segments : 1
Flags : EBGP-learned
Label |
Description |
---|---|
BGP Router ID |
Displays the local BGP router ID |
AS |
Displays the configured AS number |
Local AS |
Displays the configured local AS setting. If not configured, the value is the same as the AS. |
Path |
Displays the AS path attribute |
Origin |
EGP — the NLRI is learned by an EGP protocol IGP — the NLRI is interior to the originating AS INCOMPLETE — NLRI was learned another way |
Next Hop |
Displays the advertised BGP next hop |
MED |
Displays the Multi-Exit Discriminator value |
Local Preference |
Displays the local preference value. This value is used if the BGP route arrives from a BGP peer without the Local Pref attribute set. It is overridden by any value set using a route policy. |
Refs |
Displays the number of routes using a specified set of path attributes |
ASes |
Displays the number of AS numbers in the AS path attribute |
Segments |
Displays the number of segments in the AS path attribute |
Flags |
EBGP-learned — path attributes learned by an eBGP peering IBGP-Learned — path attributes learned by an iBGP peering |
Aggregator |
Displays the route aggregator ID |
Community |
Displays the BGP community attribute list |
Originator ID |
Displays the originator ID path attribute value |
Cluster List |
Displays the route reflector cluster list |
routes
Syntax
routes [family] [brief]
routes [family] prefix [detail | longer | hunt [brief]]
routes [family [type mvpn-type]] community comm-id
routes [family [type mvpn-type]] aspath-regex reg-ex
routes ms-pw [rd rd] [aii-type2 aii-type2] [brief]
routes l2-vpn l2vpn-type {[rd rd] | [siteid site-id] | [veid veid] [offset vpls-base-offset ]}
Context
show>router>bgp
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command displays BGP route information.
If this command is issued without any parameters, the entire BGP routing table is displayed.
If this command is issued with an IP prefix/mask or IP address, the best match for the parameter is displayed.
Parameters
- family
Specifies the type of routing information distributed by the BGP instance.
- brief
Keyword that provides a summarized display of the set of peers tow hich a BGP route is advertised.
- prefix
Specifies the type of routing information to display.
- filter
Specifies route criteria.
- aspath-regex reg-ex
Displays all routes with an AS path matching the specified regular expression reg-exp.
- community comm-id
Displays all routes with the specified BGP community.
- rd
Specifies the route distinguisher.
- veid
Specifies the VE ID.
- vpls-base-offset
Specifies the VPLS base offset value.
- site-id
Specifies the site ID.
- l2vpn-type
Specifies the L2 VPN type.
- ms-pw
Displays routes for the MS-PW family.
Output
The following output is an example of BGP route information, and Output fields: BGP routes describes the output fields.
Sample output*A:Dut-C# show router bgp routes hunt 10.1.1.1/32
===============================================================================
BGP Router ID:10.20.1.3 AS:5000 Local AS:5000
===============================================================================
Legend -
Status codes : u - used, s - suppressed, h - history, d - decayed, * -
valid Origin codes : i - IGP, e - EGP, ? - incomplete, > - best
===============================================================================
BGP IPv4 Routes
===============================================================================
-------------------------------------------------------------------------------
RIB In Entries
-------------------------------------------------------------------------------
Network : 10.1.1.1/32
Nexthop : 10.20.1.1
From : 10.20.1.1
Res. Nexthop : 10.20.1.1 (RSVP LSP: 1)
Local Pref. : 100 Interface Name : ip-10.10.2.3
Aggregator AS : None Aggregator : None
Atomic Aggr. : Not Atomic MED : None
Community : No Community Members
Cluster : No Cluster Members
Originator Id : None Peer Router Id : 10.20.1.1
Flags : Used Valid Best Incomplete
AS-Path : No As-Path
-------------------------------------------------------------------------------
RIB Out Entries
-------------------------------------------------------------------------------
-------------------------------------------------------------------------------
Routes : 1
===============================================================================
A:ALA-12>config>router>bgp# show router bgp routes family ipv4
===============================================================================
BGP Router ID : 10.10.10.103 AS : 200 Local AS : 200
===============================================================================
Legend -
Status codes : u - used, s - suppressed, h - history, d - decayed, * - valid
Origin codes : i - IGP, e - EGP, ? - incomplete, > - best
===============================================================================
BGP Routes
===============================================================================
Flag Network Nexthop LocalPref MED
VPN Label As-Path
-------------------------------------------------------------------------------
No Matching Entries Found
===============================================================================
A:ALA-12>config>router>bgp#
A:ALA-12>config>router>bgp# show router bgp routes 10.1.0.0/24 de
===============================================================================
BGP Router ID : 10.128.0.161 AS : 65535 Local AS : 65535
===============================================================================
Legend - Status codes : u - used, s - suppressed, h - history, d - decayed, * -
valid Origin codes : i - IGP, e - EGP, ? - incomplete, > - best
===============================================================================
BGP Routes
===============================================================================
Original Attributes
Network : 10.1.0.0/24 Nexthop :10.20.1.20
Route Dist. : 10070:100 VPN Label :152784
From : 10.20.1.20 Res. Nexthop:10.130.0.2
Local Pref. :100
Aggregator AS:none Aggregator : none
Atomic Aggr.:Not Atomic MED :none
Community :target:10070:1
Cluster :No Cluster Members
Originator Id:None Peer Router Id:10.20.1.20
Flags :Used Valid Best IGP
AS-Path :10070 {14730}
Modified Attributes
Network :10.1.0.0/24 Nexthop :10.20.1.20
Route Dist.: 10001:100 VPN Label :152560
From :10.20.1.20 Res. Nexthop :10.130.0.2
Local Pref.:100
Aggregator AS: none Aggregator:none
Atomic Aggr.:Not Atomic MED :none
Community :target:10001:1
Cluster :No Cluster Members
Originator Id:None Peer Router Id:10.20.1.20
Flags :Used Valid Best IGP
AS-Path :No As-Path
-------------------------------------------------------------------------------
...
===============================================================================
A:ALA-12>config>router>bgp#
A:7210-12# show router bgp routes 10.0.0.0/30 hunt
===============================================================================
BGP Router ID : 10.20.1.1 AS : 100Local AS : 100
===============================================================================
Legend -
Status codes : u - used, s - suppressed, h - history, d - decayed, * - valid
Origin codes : i - IGP, e - EGP, ? - incomplete, > - best
===============================================================================
BGP Routes
===============================================================================
RIB In Entries
-------------------------------------------------------------------------------
Network : 10.0.0.0/30
Nexthop : 10.20.1.2
Route Dist. : 10.20.1.2:1VPN Label: 131070
From : 10.20.1.2
Res. Nexthop : 10.10.1.2
Local Pref. : 100Interface Name: to-sr7
Aggregator AS : noneAggregator: none
Atomic Aggr. : Not AtomicMED: none
Community : target:10.20.1.2:1
Cluster : No Cluster Members
Originator Id : NonePeer Router Id: 10.20.1.2
Flags : Used Valid Best IGP
AS-Path : No As-Path
VPRN Imported : 1 2 10 12
-------------------------------------------------------------------------------
RIB Out Entries
-------------------------------------------------------------------------------
Routes : 1
===============================================================================
A:7210-12#
*A:Dut-C>config>router>policy-options# show router bgp routes 10.10.0.0/24 hunt
===============================================================================
BGP Router ID:10.20.1.3 AS:300 Local AS:300
===============================================================================
Legend -
Status codes : u - used, s - suppressed, h - history, d - decayed, * - valid
l - leaked, x - stale, > - best, b - backup, p - purge
Origin codes : i - IGP, e - EGP, ? - incomplete
===============================================================================
BGP IPv4 Routes
===============================================================================
-------------------------------------------------------------------------------
RIB In Entries
-------------------------------------------------------------------------------
Network : 10.10.0.0/24
Nexthop : 10.20.1.2
Path Id : None
From : 10.20.1.2
Res. Nexthop : 10.10.11.2 (LDP)
Local Pref. : 100 Interface Name : INT_TO_C3_D_1
Aggregator AS : None Aggregator : None
Atomic Aggr. : Not Atomic MED : None
AIGP Metric : 555
Connector : None
Community : No Community Members
Cluster : No Cluster Members
Originator Id : None Peer Router Id : 10.20.1.2
IPv4 Label : 131065
Flags : Used Valid Best IGP
Route Source : Internal
AS-Path : 400 500
Route Tag : 0
Neighbor-AS : 400
Orig Validation: NotFound
Add Paths Send : Default
Last Modified : 00h15m47s
Network : 10.10.0.0/24
Nexthop : 10.20.1.4
Path Id : None
From : 10.20.1.4
Res. Nexthop : 10.10.5.4 (LDP)
Local Pref. : 100 Interface Name : INT_TO_C4_E_1
Aggregator AS : None Aggregator : None
Atomic Aggr. : Not Atomic MED : None
AIGP Metric : None
Connector : None
Community : No Community Members
Cluster : No Cluster Members
Originator Id : None Peer Router Id : 10.20.1.4
IPv4 Label : 131065
Flags : Valid IGP
TieBreakReason : AIGP
Route Source : Internal
AS-Path : 400 500
Route Tag : 0
Neighbor-AS : 400
Orig Validation: NotFound
Add Paths Send : Default
Last Modified : 00h15m49s
Network : 10.10.0.0/24
Nexthop : 10.10.1.1
Path Id : None
From : 10.10.1.1
Res. Nexthop : 10.10.1.1
Local Pref. : None Interface Name : INT_TO_C1_A
Aggregator AS : None Aggregator : None
Atomic Aggr. : Not Atomic MED : None
AIGP Metric : None
Connector : None
Community : No Community Members
Cluster : No Cluster Members
Originator Id : None Peer Router Id : 10.20.1.1
IPv4 Label : 131071
Flags : Invalid IGP AS-Loop
Route Source : External
AS-Path : 200 300 400 500
Route Tag : 0
Neighbor-AS : 200
Orig Validation: NotFound
Add Paths Send : Default
Last Modified : 00h15m48s
-------------------------------------------------------------------------------
RIB Out Entries
-------------------------------------------------------------------------------
Network : 10.10.0.0/24
Nexthop : 10.20.1.2
Path Id : None
To : 10.20.1.4
Res. Nexthop : n/a
Local Pref. : 100 Interface Name : NotAvailable
Aggregator AS : None Aggregator : None
Atomic Aggr. : Not Atomic MED : 100
AIGP Metric : 555
Connector : None
Community : No Community Members
Cluster : 10.20.1.3
Originator Id : 10.20.1.2 Peer Router Id : 10.20.1.4
IPv4 Label : 131065
Origin : IGP
AS-Path : 400 500
Route Tag : 0
Neighbor-AS : 400
Orig Validation: NotFound
Network : 10.10.0.0/24
Nexthop : 10.20.1.2
Path Id : None
To : 10.20.1.2
Res. Nexthop : n/a
Local Pref. : 100 Interface Name : NotAvailable
Aggregator AS : None Aggregator : None
Atomic Aggr. : Not Atomic MED : 100
AIGP Metric : 555
Connector : None
Community : No Community Members
Cluster : 10.20.1.3
Originator Id : 10.20.1.2 Peer Router Id : 10.20.1.2
IPv4 Label : 131065
Origin : IGP
AS-Path : 400 500
Route Tag : 0
Neighbor-AS : 400
Orig Validation: NotFound
Network : 10.10.0.0/24
Nexthop : 10.20.1.2
Path Id : None
To : 10.20.1.5
Res. Nexthop : n/a
Local Pref. : 100 Interface Name : NotAvailable
Aggregator AS : None Aggregator : None
Atomic Aggr. : Not Atomic MED : None
AIGP Metric : 555
Connector : None
Community : No Community Members
Cluster : 10.20.1.3
Originator Id : 10.20.1.2 Peer Router Id : 10.20.1.5
IPv4 Label : 131065
Origin : IGP
AS-Path : 400 500
Route Tag : 0
Neighbor-AS : 400
Orig Validation: NotFound
Network : 10.10.0.0/24
Nexthop : 10.10.1.3
Path Id : None
To : 10.10.1.1
Res. Nexthop : n/a
Local Pref. : n/a Interface Name : NotAvailable
Aggregator AS : None Aggregator : None
Atomic Aggr. : Not Atomic MED : None
AIGP Metric : None
Connector : None
Community : No Community Members
Cluster : No Cluster Members
Originator Id : None Peer Router Id : 10.20.1.1
IPv4 Label : 131067
Origin : IGP
AS-Path : 300 400 500
Route Tag : 0
Neighbor-AS : 300
Orig Validation: NotFound
-------------------------------------------------------------------------------
Routes : 7
===============================================================================
*A:Dut-C>config>router>policy-options#
*A:7210SAS# show router bgp routes mvpn-ipv4
===============================================================================
BGP Router ID:16.16.16.16 AS:100 Local AS:100
===============================================================================
Legend -
Status codes : u - used, s - suppressed, h - history, d - decayed, * - valid
Origin codes : i - IGP, e - EGP, ? - incomplete, > - best, b - backup
===============================================================================
BGP MVPN-IPv4 Routes
===============================================================================
Flag RouteType OriginatorIP LocalPref MED
RD SourceAS VPNLabel
Nexthop SourceIP
As-Path GroupIP
-------------------------------------------------------------------------------
u*>i Intra-Ad 10.17.17.17 100 0
1:2 - -
17.17.17.17 -
No As-Path -
*i Source-Join - 100 0
1:2 100 -
1.1.1.1 10.1.1.2
No As-Path 239.1.1.1
*i Source-Join - 100 0
1:2 100 -
2.2.2.2 10.1.1.2
No As-Path 239.1.1.1
*i Source-Join - 100 0
1:2 100 -
1.1.1.1 10.1.1.2
No As-Path 239.1.1.2
*i Source-Join - 100 0
1:2 100 -
2.2.2.2 10.1.1.2
No As-Path 239.1.1.2
*A:7210SAS#
*A:praragon-sim1# show router bgp routes mvpn-ipv4 type source-join
source-as 200 source-ip 10.100.1.2 group-ip 239.0.0.0 detail
===============================================================================
BGP Router ID:10.20.1.3 AS:200 Local AS:200
===============================================================================
Legend -
Status codes : u - used, s - suppressed, h - history, d - decayed, * - valid
Origin codes : i - IGP, e - EGP, ? - incomplete, > - best
===============================================================================
BGP MVPN-IPv4 Routes
===============================================================================
Route Type : Source-Join
Route Dist. : 1:1
Source AS : 200
Source IP : 10.100.1.2
Group IP : 239.0.0.0
Nexthop : 10.20.1.4
From : 10.20.1.4
Res. Nexthop : 0.0.0.0
Local Pref. : 100 Interface Name : NotAvailable
Aggregator AS : None Aggregator : None
Atomic Aggr. : Not Atomic MED : 0
Community : target:10.20.1.3:2
Cluster : No Cluster Members
Originator Id : None Peer Router Id : 10.20.1.4
Flags : Used Valid Best IGP
AS-Path : No As-Path
-------------------------------------------------------------------------------
Routes : 1
===============================================================================
*A:praragon-sim1#
Label |
Description |
---|---|
BGP Router ID |
Displays the local BGP router ID |
AS |
Displays the configured autonomous system number |
Local AS |
Displays the configured local AS setting. If not configured, the value is the same as the AS. |
Route Dist. |
Displays the route distinguisher identifier attached to routes that distinguishes the VPN it belongs |
VPN Label |
Displays the label generated by the PE label manager |
Network |
Displays the IP prefix and mask length |
Nexthop |
Displays the BGP next hop |
From |
Displays the advertising BGP neighbor IP address |
Res. Nexthop |
Displays the resolved next hop |
Local Pref. |
Displays the local preference value. This value is used if the BGP route arrives from a BGP peer without the Local Pref attribute set. It is overridden by any value set using a route policy. |
Flag |
u — used s — suppressed h — history d — decayed * — valid i — igp e — egp ? — incomplete > — best |
Aggregator AS |
The aggregator AS value none — aggregator AS attributes are not present |
Aggregator |
The aggregator attribute value none — aggregator attributes are not present |
Atomic Aggr. |
Atomic — the atomic aggregator flag is set Not Atomic — the atomic aggregator flag is not set |
MED |
Displays the MED metric value none — MED metrics are present |
Community |
Displays the BGP community attribute list |
Cluster |
Displays the route reflector cluster list |
Originator Id |
Displays the originator ID path attribute value none — the originator ID attribute is not present |
Peer Router Id |
Displays the router ID of the advertising router |
AS-Path |
Displays the BGP AS path attribute |
VPRN Imported |
Displays the VPRNs where a particular BGP-VPN received route has been imported and installed |
summary
Syntax
summary [all]
summary [family family] [neighbor ip-address]
Context
show>router>bgp
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command displays a summary of BGP neighbor information.
The ‟State” field displays the global BGP operational state. The valid values are the following:
Up
The BGP global process is configured and running.
Down
The BGP global process is administratively shutdown and not running.
Disabled
The BGP global process is operationally disabled. The process must be restarted by the operator.
For example, if a BGP peer is operationally disabled, the state in the summary table shows the state ‟Disabled.”
Parameters
- family
Specifies the type of routing information to be distributed by the BGP instance.
- neighbor ip-address
Clears damping information for entries received from the BGP neighbor.
Output
The following output is an example of summary BGP neighbor information, and Output fields: BGP summary describes the output fields.
Sample outputA:Dut-C# show router bgp summary neighbor 3FFE::A0A:1064
===============================================================================
BGP Router ID : 10.20.1.3 AS : 100 Local AS : 100
===============================================================================
BGP Admin State : Up BGP Oper State : Up
Number of Peer Groups : 4 Number of Peers : 5
Total BGP Paths : 8 Total Path Memory : 1212
Total BGP Active Rts. : 0 Total BGP Rts. : 0
Total Supressed Rts. : 0 Total Hist. Rts. : 0
Total Decay Rts. : 0
Total VPN Peer Groups : 0 Total VPN Peers : 0
Total VPN Local Rts. : 0
Total VPN Remote Rts. : 0 Total VPN Remote Active Rts.: 0
Total VPN Supp. Rts. : 0 Total VPN Hist. Rts. : 0
Total VPN Decay Rts. : 0
Total IPv6 Remote Rts. : 5 Total IPv6 Rem. Active Rts. : 4
===============================================================================
BGP Summary
===============================================================================
Neighbor
AS PktRcvd InQ Up/Down State|Rcv/Act/Sent (IPv4)
PktSent OutQ Rcv/Act/Sent (VpnIPv4)
Rcv/Act/Sent (IPv6)
Rcv/Act/Sent (MCastIPv4)
-------------------------------------------------------------------------------
103 489 0 00h40m28s IPv4 Incapable
569 0 VPN-IPv4 Incapable
1/1/3
===============================================================================
A:Dut-C#
A:SetupCLI>show>router# bgp summary
===============================================================================
BGP Router ID : 10.3.4.5 AS : 35012 Local AS : 100
===============================================================================
BGP Admin State : Up BGP Oper State : Up
Confederation AS : 40000
Member Confederations : 35012 65205 65206 65207 65208
Rapid Withdrawal : Disabled
Bfd Enabled : Yes
Number of Peer Groups : 1 Number of Peers : 1
Total BGP Paths : 3 Total Path Memory : 396
Total BGP Active Rts. : 0 Total BGP Rts. : 0
Total Supressed Rts. : 0 Total Hist. Rts. : 0
Total Decay Rts. : 0
Total VPN Peer Groups : 1 Total VPN Peers : 1
Total VPN Local Rts. : 0
Total VPN Remote Rts. : 0 Total VPN Remote Active Rts.: 0
Total VPN Supp. Rts. : 0 Total VPN Hist. Rts. : 0
Total VPN Decay Rts. : 0
===============================================================================
BGP Summary
===============================================================================
Neighbor
AS PktRcvd InQ Up/Down State|Rcv/Act/Sent (IPv4)
PktSent OutQ Rcv/Act/Sent (VpnIPv4)
Rcv/Act/Sent (MCastIPv4)
-------------------------------------------------------------------------------
10.3.3.3 20 0 0 01h55m56s Active
0 0
===============================================================================
A:SetupCLI>show>router#
Label |
Description |
---|---|
BGP Router ID |
Displays the local BGP router ID |
AS |
Displays the configured autonomous system number |
Local AS |
Displays the configured local AS setting. If not configured, the value is the same as the AS. |
BGP Admin State |
Down — BGP is administratively disabled Up — BGP is administratively enabled |
BGP Oper State |
Down — BGP is operationally disabled Up — BGP is operationally enabled |
Bfd |
Yes — BFD is enabled No — BFD is disabled |
Number of Peer Groups |
Displays the total number of configured BGP peer groups |
Number of Peers |
Displays the total number of configured BGP peers |
Total BGP Active Routes |
Displays the total number of BGP routes used in the forwarding table |
Total BGP Routes |
Displays the total number of BGP routes learned from BGP peers |
Total BGP Paths |
Displays the total number of unique sets of BGP path attributes learned from BGP peers |
Total Path Memory |
Displays the total amount of memory used to store the path attributes |
Total Suppressed Routes |
Displays the total number of suppressed routes as a result of route damping |
Total History Routes |
Displays the total number of routes with history as a result of route damping |
Total Decayed Routes |
Displays the total number of decayed routes as a result of route damping |
Total VPN Peer Groups |
Displays the total number of configured VPN peer groups |
Total VPN Peers |
Displays the total number of configured VPN peers |
Total VPN Local Rts |
Displays the total number of configured local VPN routes |
Total VPN Remote Rts |
Displays the total number of configured remote VPN routes |
Total VPN Remote Active Rts. |
Displays the total number of active remote VPN routes used in the forwarding table |
Total VPN Supp.Rts. |
Displays the total number of suppressed VPN routes as a result of route damping |
Total VPN Hist. Rts. |
Displays the total number of VPN routes with history as a result of route damping |
Total VPN Decay Rts. |
Displays the total number of decayed routes as a result of route damping |
Neighbor |
Displays the BGP neighbor address |
AS (Neighbor) |
Displays the BGP neighbor autonomous system number |
PktRcvd |
Displays the total number of packets received from the BGP neighbor |
PktSent |
Displays the total number of packets sent to the BGP neighbor |
InQ |
Displays the number of BGP messages to be processed |
OutQ |
Displays the number of BGP messages to be transmitted |
Up/Down |
Displays the amount of time that the BGP neighbor has either been established or not established depending on its current state |
State|Recv/Actv/Sent |
Displays the BGP neighbor current state (if not established) or the number of received routes, active routes and sent routes (if established) |
Clear commands
damping
Syntax
damping [{ip-prefix/ip-prefix-length] [neighbor ip-address]} | [group name]
Context
clear>router>bgp
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command clears or resets the route damping information for received routes.
Parameters
- ip-prefix/ip-prefix-length
Clears damping information for entries that match the IP prefix and prefix length.
- neighbor ip-address
Clears damping information for entries received from the BGP neighbor.
- group name
Clears damping information for entries received from any BGP neighbors in the peer group.
flap-statistics
Syntax
flap-statistics [[ip-prefix/mask] [neighbor ip-address]] | [group group-name] | [regex reg-exp] | [policy policy-name]
Context
clear>router>bgp
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command clears route flap statistics.
Parameters
- ip-prefix/mask
Clears route flap statistics for entries that match the specified IP prefix and mask length.
- neighbor ip-address
Clears route flap statistics for entries received from the specified BGP neighbor.
- group group-name
Clears route flap statistics for entries received from any BGP neighbors in the specified peer group.
- regex reg-exp
Clears route flap statistics for all entries that have the regular expression and the AS path that matches the regular expression.
- policy policy-name
Clears route flap statistics for entries that match the specified route policy.
neighbor
Syntax
neighbor {ip-address | as as-number | external | all} [soft | soft-inbound]
neighbor {ip-address | as as-number | external | all} statistics
neighbor ip-address end-of-rib
Context
clear>router>bgp
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command resets the specified BGP peers. This can cause existing BGP connections to be shut down and restarted.
Parameters
- ip-address
Resets the BGP neighbor with the specified IP address.
- as as-number
Resets all BGP neighbors with the specified peer AS.
- external
Keyword that resets all EBGP neighbors.
- all
Keyword that resets all BGP neighbors.
- soft
Keyword that specifies the BGP neighbors reevaluate all routes in the local-RIB against the configured export policies.
- soft-inbound
Keyword that specifies BGP neighbors reevaluate all routes in the RIB-In against the configures import policies.
- statistics
Keyword that clears the BGP neighbor statistics.
- end-of-rib
Keyword that clears the routing information base (RIB).
protocol
Syntax
protocol
Context
clear>router>bgp
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command resets the entire BGP protocol.
Debug commands
events
Syntax
events [neighbor ip-address | group name]
no events
Context
debug>router>bgp
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command logs all events changing the state of a BGP peer.
Parameters
- neighbor ip-address
Debugs only events affecting the specified BGP neighbor.
- group name
Debugs only events affecting the specified peer group and associated neighbors.
keepalive
Syntax
keepalive [neighbor ip-addr | group name]
no keepalive
Context
debug>router>bgp
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command decodes and logs all sent and received keepalive messages in the debug log.
Parameters
- neighbor ip-address
Debugs events affecting only the specified BGP neighbor.
- group name
Debugs events affecting only the specified peer group and associated neighbors.
notification
Syntax
notification [neighbor ip-address | group name]
no notification
Context
debug>router>bgp
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command decodes and logs all sent and received notification messages in the debug log.
Parameters
- neighbor ip-address
Debugs events affecting only the specified BGP neighbor.
- group name
Debugs events affecting only the specified peer group and associated neighbors.
open
Syntax
open [neighbor ip-address | group name]
no open
Context
debug>router>bgp
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command decodes and logs all sent and received open messages in the debug log.
Parameters
- neighbor ip-address
Debugs events affecting only the specified BGP neighbor.
- group name
Debugs events affecting only the specified peer group and associated neighbors.
outbound-route-filtering
Syntax
[no] outbound-route-filtering
Context
debug>router>bgp
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command enables debugging for all BGP ORF packets. ORF is used to inform a neighbor of targets (using target-list) that it is willing to receive.
packets
Syntax
packets [neighbor ip-address | group name]
packets
Context
debug>router>bgp
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command decodes and logs all sent and received BGP packets in the debug log.
Parameters
- neighbor ip-address
Debugs events affecting only the specified BGP neighbor.
- group name
Debugs events affecting only the specified peer group and associated neighbors.
route-refresh
Syntax
route-refresh [neighbor ip-address | group name]
no route-refresh
Context
debug>router>bgp
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command enables and disables debugging for BGP route-refresh.
Parameters
- neighbor ip-address
Debugs events affecting only the specified BGP neighbor.
- group name
Debugs events affecting only the specified peer group and associated neighbors.
rtm
Syntax
rtm [neighbor ip-address | group name]
no rtm
Context
debug>router>bgp
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command logs RTM changes in the debug log.
Parameters
- neighbor ip-address
Debugs events affecting only the specified BGP neighbor.
- group name
Debugs events affecting only the specified peer group and associated neighbors.
socket
Syntax
socket [neighbor ip-address | group name]
no socket
Context
debug>router>bgp
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command logs all TCP socket events to the debug log.
Parameters
- neighbor ip-address
Debugs events affecting only the specified BGP neighbor.
- group name
Debugs events affecting only the specified peer group and associated neighbors.
timers
Syntax
timers [neighbor ip-address | group name]
no timers
Context
debug>router>bgp
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command logs all BGP timer events to the debug log.
Parameters
- neighbor ip-address
Debugs events affecting only the specified BGP neighbor.
- group name
Debugs events affecting only the specified peer group and associated neighbors.
update
Syntax
update [neighbor ip-address | group name]
no update
Context
debug>router>bgp
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command decodes and logs all sent and received update messages in the debug log.
Parameters
- neighbor ip-address
Debugs events affecting only the specified BGP neighbor.
- group name
Debugs events affecting only the specified peer group and associated neighbors.