Advice Needed From L2TPV3 / Pseud Wire Expert

[BrianChernish]

I have an L2TPV3 / Pseudo Wire link established from a Remote Site to my Headend.

Connection between the 2 ASRs is over a Site-To-Site VPN Tunnel

The Remote Site has 2 separate and distinct Networks

• Network 1 subnet 10.101.12.0/24
• Network 2 subnet 10.101.13.0/24

The Head End has 2 Routers, which are the Gateway of Last Resort for their respective subnets

• Router 1 10.101.12.254/24
• Router 2 10.101.13.254/24

So my question is this: will the pseudo wire virtual circuit be able to deal with traffic from the 2 distinct subnets to the 2 routers without getting things confused?

I have boiled this down to this simple analogy purposely to try and keep the question as simple as possible. If requested I can provide more detailed Visio Drawings and complete router / VPN configs.

It is worth noting that I have Remote Network 1 working correctly and “talking to” its Gateway at the Head End. BUT I run into problems when I try to introduce traffic from Remote Network 2.

[Giuseppe Larosa]

Hello B-chernish,

an L2TPv3 pseudowire is a pure point to point L2 transport service over an IP internetwork.

It takes frames entering the access link FA0 on remote site C891 in your network diagram, it encapsulates each of them in an IP packet using the L2TPv3 protocol  with a destination on the headend C891 IP address.

The receiving router on the headend site de-encapsulates the L2TPv3 frames and delivers them as ethernet frames  to the access link associated to the pseudowire that is FA0 on C891 on headend site, so ethernet frames are delivered to the first motorola router with IP address 10.101.12.254.

Now, you would like to support the second IP subnet between FA1 of remote site C891 and the FA1 of C891 on headend site that connects to the second motorola router with IP address 10.101.13.254.

I notice that you have both access interfaces in Vlan2 on the remote site.

First of all, different IP subnets should be associated to different Vlans.

So you should create vlan 3 for example, and make FA1 a switchport that is member of vlan 3.

The same should be done on the headend site FA1 should be in a different Vlan then FA0.

At this point you are ready to configure a second L2TPv3 pseudowire from FA1 of C891 in remote site to FA1 of C891 of head end site.

This second point to point service will carry ethernet frames associated with Vlan 3 - IP subnet 10.101.13.0/24.

I don't know how you have configured the first L2TPv3 pseudowire if using the physical access port FA0 or the SVI interface Vlan2.

But you should be able to replicate using the new vlan3 or the physical interface FA1.

Hope to help

Giuseppe