Configuration Examples L2 Protocol Tunneling

I looking for some configuration examples of using L2PT. I have 2 X460 w/Core licensing at different locations. I would like to create a layer 2 tunnel between this two switches over a MPLS circuit. Basically extending a layer 2 VLAN in to two locations. The two switch do not participate in the MPLS environment. Any help?

1 reply

Userlevel 6

L2PT does not create a layer 2 tunnel between two devices, it just encapsulates L2 protocols so they can traverse switches to a destination over a layer 2 path without being "interpreted" by the switches transporting them.

Imagine that you are trying to send STP information to a remote site. If you sent STP BPDUs through a vlan, the first switch has STP enabled will send the BPDU to the STP protocol process instead of transmitting it as regular traffic. To prevent this you must use L2TP to encapsulate the BPDU so the switch considers it "traffic" and forwards it. The same goes for LACP and other L2 protocols.

If you want to create a Layer 2 tunnel between two switches over an MPLS network you will need to create a VPLS tunnel between them. To do so, the X460s will need MPLS licenses...