Layer 2 control protocols
SR OS has awareness of multiple Layer 2 Control Protocols (L2CP). In some configurations, these L2CP frames are extracted and processed by the receiving SR. However, there are some deployments where it is useful to have the SR transparently forward the L2CP frames through a Layer 2 VLL or VPLS service. The SR OS support for transparent tunneling is configured on a protocol basis, as described in this section.
L2CP frames are processed as follows:
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tunneled
SR OS passes the frames through any associated service.
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peered
SR OS extracts and processes the frame.
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discarded
SR OS extracts the frame and then discards it.
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STP/RSTP/MSTP (assuming Spanning Tree is not enabled if the ingress SAP is attached to a VPLS service)
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LAMP
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MAC specific control protocols
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provider bridge group address
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provider bridge MVRP address
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PAUSE frames
PAUSE frames are transmitted to request backward direction flow control. By default, SR OS peers pause frames on reception and pause the transmit side of the port. On some ports, this behavior can be changed to discard PAUSE frames. For applicable ports, use the following command to discard PAUSE frames:
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MD-CLI
configure port ethernet discard-rx-pause-frames true
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classic CLI
configure port ethernet discard-rx-pause-frames
PAUSE frames are never tunneled.
PAUSE frames are identified as frames with Ethertype (0x8808).
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LACP frames
If the port is part of a LAG, the LACP frames are peered. If the port is not part of a LAG, the LACP frames are discarded or tunneled based on the configuration of the following command.
configure port ethernet lacp-tunnel
LACP frames are identified as frames with Ethertype (0x8809) and the slow-protocol subtype (0x01).
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EFM-OAM frames
If the port has EFM-OAM processing enabled, the EFM-OAM frames are peered. If EFM-OAM processing is not enabled on the port, the EFM-OAM frames are discarded or tunneled based on the configuration of the following command.
configure port ethernet efm-oam tunneling
EFM-OAM frames are identified as frames with Ethertype (0x8809) and the slow-protocol sub-type (0x03).
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ESMC frames
If the port is an input reference to the central frequency clock, the ESMC frames are peered. If the port is not an input reference to the central frequency clock, the ESMC frames are discarded. Use the following command to override the preceding scenarios and tunnel the ESMC frames:
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MD-CLI
configure port ethernet ssm esmc-tunnel true
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classic CLI
configure port ethernet ssm esmc-tunnel
ESMC frames are identified as frames with Ethertype (0x8809) and the slow-protocol sub-type (0x0A).
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802.1x frames
By default, the 802.1x frames are extracted when they are received. For extracted frames, if a RADIUS server is configured, the frames are peered; otherwise, they are discarded. Use the following command to override the extraction and tunnel the 802.1x frames:
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MD-CLI
configure port ethernet dot1x tunneling true
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classic CLI
configure port ethernet dot1x tunneling
802.1x frames are identified as frames with Ethertype (0x888E).
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E-LMI frames
If Ethernet Local Management Interface (E-LMI) processing is enabled on the port, E-LMI frames are peered. Otherwise, the E-LMI frames are dropped from VPLS and tunneled for Epipe.
E-LMI frames from VPLS are tunneled when the following is the case:
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the following command is included in the service
configure service vpls tunnel-elmi
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the following command is not enabled on the port
configure port ethernet elmi
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the encapsulation of the E-LMI frame matches the VPLS service tagging
E-LMI frames are identified as frames with Ethertype (0x88EE) and a destination MAC address of 01:80:C2:00:00:07.
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LLDP frames
If LLDP processing is enabled on the port, LLDP frames are peered. Otherwise, LLDP frames are discarded or tunneled based on the configuration of the following command.
configure port ethernet lldp dest-mac tunnel-nearest-bridge
LLDP frames are identified as frames with Ethertype (0x88CC) and destination MAC address of 01-80-C2-00-00-0E.
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PTP peer delay frames
If the port is configured in the router as an active port within the PTP process, the frames are peered; otherwise, the frames are tunneled.
PTP message frames are identified as frames with Ethertype (0x88F7).
Configure the following commands on the port to achieve the maximum transparency of L2CP frames:
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MD-CLI
configure port ethernet discard-rx-pause-frames true configure port ethernet lacp-tunnel true configure port ethernet efm-oam tunneling true configure port ethernet ssm esmc-tunnel true configure port ethernet dot1x tunneling true configure port ethernet lldp dest-mac tunnel-nearest-bridge true
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classic CLI
configure port ethernet discard-rx-pause-frames configure port ethernet lacp-tunnel configure port ethernet efm-oam tunneling configure port ethernet ssm esmc-tunnel configure port ethernet dot1x tunneling configure port ethernet lldp dest-mac tunnel-nearest-bridge