MPLS and QinQ

[mike]

Hi,

I have a layer 2 circuit which supports QinQ, could I configure MPLS on that circuit or that interface? Do I only need to concern MTU size over that interface?

Thx

[olorunloba]

I do not fully understand, but MPLS is configured on L3 interfaces that supports CEF.

[shailendra.singh]

Hi,

If your CE at both ends are routers, then you can configure both CE's with a Sub interface on the trunk link that is going towards PE. On this Sub interface of CEs you can configure IP address and also, if CEF is enabled on router and the interface then you can use mpls ip command on this sub interface and form LDP neighborship between both CEs over this l2 circuit.

Yes MTU size will have to be capable of supporting this increased packet size.

Regards,

Shailendra

[charlestran]

Set system mtu 1546.

Reset the router to take affect.

We have tried with various MTU size and this 1546 has been perfect for QinQ MPLS network.

Hope to save you a lot of headache.

[jwilde]

If you are just doing qinq, then you only need 1504.

System MTU size is 1504 bytes

System Jumbo MTU size is 1504 bytes