Layer 2 control protocols

The following L2CP frames are always tunneled:

• STP/RSTP/MSTP (assuming Spanning Tree is not enabled if the ingress SAP is attached to a VPLS service)

• LAMP

• MAC Specific Control Protocols

• Provider Bridge Group Address

• Provider Bridge MVRP Address

Other frame types are processed according to CLI configuration, as follows:

• PAUSE frames

  PAUSE frames are transmitted to request backward direction flow control. By default, SR OS peers these frames on reception and pauses the transmit side of the port. On some ports, this behavior can be changed to discard these frames by using the config>port>ethernet discard-rx-pause-frames CLI command.

  PAUSE frames are never tunneled.

  PAUSE frames are identified as frames with Ethertype (0x8808).

• 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 tunnelled according to the configuration of the config>port>ethernet lacp-tunnel CLI command.

  LACP frames are identified as frames with Ethertype (0x8809) and the slow-protocol subtype (0x01)

• 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 tunnelled according to the configuration of the config>port>ethernet lacp-tunnel CLI command.

  EFM-OAM frames are identified as frames with Ethertype (0x8809) and the slow-protocol sub-type (0x03).

• 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. To override the preceding scenarios and tunnel the ESMC frames, configure the config>port>ethernet>ssm esmc-tunnel CLI command.

  ESMC frames are identified as frames with Ethertype (0x8809) and the slow-protocol sub-type (0x0A).

• 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. The extraction can be overridden and the 802.1x frames can be tunnelled by using the config>port>ethernet>dot1x tunneling CLI command.

  802.1x frames are identified as frames with Ethertype (0x888E).

• E-LMI frames

  If Ethernet Local Management Interface (E-LMI) processing is enabled on the port, E-LMI frames are peered. Otherwise, E-LMI frames are tunneled according to the configuration of the config>port>ethernet lacp-tunnel CLI command.

  E-LMI frames are identified as frames with Ethertype (0x88EE) and a destination MAC address of 01:80:C2:00:00:07.

• LLDP frames

  If LLDP processing is enabled on the port, LLDP frames are peered. Otherwise, LLDP frames are discarded or tunneled according to the configuration of the config>port>ethernet>lldp>dst-mac tunnel-nearest-bridge CLI command.

  LLDP frames are identified as frames with Ethertype (0x88CC) and destination MAC address of 01-80-C2-00-00-0E.

• 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).

The maximum transparency of L2CP frames is achieved by configuring the following CLI commands on the port:

config port ethernet 
  discard-rx-pause-frames
  lacp-tunnel
  efm-oam tunnelling
  ssm esmc-tunnel
  dot1x tunneling
  lldp dst-mac tunnel-nearest-bridge