Layer 2 Protocol Tunneling (L2PT/L2CP Tunneling)
L2CP tunneling provides support for tunneling Control plane frames between CE nodes.
When control frames received at CEP port of PE bridge, predefined multicast address (01-00-C2-CD-CD-D0) is used for tunneling the packets across service provider network. If control packets are customer vlan tagged or untagged, then PE bridge will append corresponding service vlan tag to the control packet as per registration table / vlan translation table mapped to the port and send it across the service provider as a data packet.
When tunneled control packet with multicast address (01-00-C2-CD-CD-D0) received on PNP port, the multicast address is replaced with corresponding control packet multicast address and cvlan/svlan removal or updating is done as per registration table / vlan translation table.
Topology
Figure 2-5 displays a sample Provider Bridged topology with customer equipment.
Figure 2-5: Provider Bridging with Customer Equipment Topology
Configuring the L2PT Protocol on the Interface
The following L2PT protocols are supported:
• EFM: Ethernet first mile (Link OAM)
• ELMI: Ethernet Local Management Interface
• LACP: Link Aggregation Control Protocol
• LLDP: Link Layer Discovery Protocol
• STP: Spanning Tree Protocols
PB1
PB1#configure terminal | Enter Configure mode. |
PB1(config)#interface eth2 | Enter Interface mode |
PB1(config-if)#l2protocol stp peer | Configure STP protocol as peer |
PB1(config-if)#l2protocol elmi tunnel | Configure Elmi protocol as tunnel |
PB1(config-if)#l2protocol lldp tunnel | Configure LLDP protocol as tunnel |
PB1(config-if)#l2protocol lacp discard | Configure LACP protocol as discard |
PB1(config-if)#l2protocol efm discard | Configure EFM protocol as discard |
PB1(config-if)#commit | Commit the configuration. |
PB1(config-if)#exit | Exit of the interface |
Validation
PB1#show l2protocol processing interface eth2
Bridge Interface Name Protocol Processing Status
====== ============== ======== =================
1 eth2 stp Peer
1 eth2 gmrp Peer
1 eth2 gvrp Peer
1 eth2 mmrp Peer
1 eth2 mvrp Peer
1 eth2 lacp Discard
1 eth2 lldp Tunnel
1 eth2 efm Discard
1 eth2 elmi Tunnel
1 eth2 ptp Peer
Last modified date: 07/06/2023