L2CP tunneling provides support for tunneling Control plane frames across VxLAN/MH.

 

 

 

 

VXLAN creates LAN segments using a MAC in IP encapsulation. The encapsulation carries the original L2

frame received from a host to the destination in another server using IP tunnels. The endpoints of the virtualized tunnel

formed using VXLAN are called VTEPs (VXLAN Tunnel EndPoints).

L2CP tunneling provides support for tunneling control plane frames across VXLAN with MH/SH combination.

Any L2CP frame that is destined towards other end with a multicast destination MAC Address for L2 protocol is decided by looking at the frame and upon the configured values of the L2CP Service Attributes.

As and when Control packets with default destination MAC address for any L2 protocol is generated, it will be forwarded by VTEPs that are part of MH towards the VTEP that is part of SH and vice versa.

During this operation, the default destination MAC address for any L2 protocol is replaced with predefined multicast address as destination for tunneling the packets across SPINE nodes. When tunneled control packet with pre-defined multicast address received on ingress port on the other end of the VTEP, the multicast address is replaced with corresponding control packet multicast address.

If control packets are received at the PE router on AC port (vlan tagged/untagged), corresponding AC port properties will take care of forwarding to peer PE node. These packets are encapsulated with MPLS headers and sent across the network to the remote PE router. The egress PE router receives the packet and performs MPLS decapsulation and forwards to the CE. Except for LACP, all other control packets are tunnels across the MPLS circuit.

When the incoming port is configured as Hybrid (Bridge+L2VPN), L2CP switches to peering mode. You can override this behavior with the help of L2CP configurations.