QinQ with ISR 4331

[Xividar]

I am wanting to pvoide a customer with L2 transport across our MPLS network, we have the XCONNECT set-up PE to PE, on the custoer side, the CE will be a ISR4331 with a switch port module. I can run a trunk to the PE, but the question is, how do I double tag the customer VLAN's? 

Thanks a lot :)

[Giuseppe Larosa]

Hello,

on the CE router try the following on a port of the switch module

interface gi1/1/0

switchport

switchport access vlan 100

switchport mode tunnel dot1q

if the last command is accepted you have the tunneling interface that is towards the internal switch

Another port has to be configured as a trunk and must allow vlan 100 the customer Vlan

interface gi1/1/1

desc to PE router

switchport

switchport trunk enc dot1q

switchport mode trunk

swiirchport trunk allowed vlan 100

!

Hope to help

Giuseppe

[Xividar]

Thanks a lot for the reply, Giuseppe, "switchport mode tunnel dot1q" isn't supported. The other question is, this would be to extend one single VLAN, true? If the customer has multiple VLAN's, then what?

[Giuseppe Larosa]

Hello,

with QinQ when supported you use a double stack of Vlans.

The external vlan 100, the one associated to the dot1q tunnel accepts frames with any Vlan tag.

So to be more precise, you need to dedicate one Vlan to each customer, but each customer can carry any Vlan over the tunnel.

In metro ethernet forum terms the external Vlan is called the S- vlan (S= service provider) and the inner Vlan is called C- vlan customer vlan.

QinQ provides the simplest way to support multiple customers without mixing their Vlans.

However, no more then four thousands customers can be supported as each customer requires a dedicated Vlan in Vlan space of the service provider.

In your case you should look at different ways to transport L2 traffic over an IP routing network

L2TPv3 provide a point to point service.

Hope to help

Giuseppe

[Xividar]

Thanks. I ended up having to go back to using an ME3400, "dot1q- tunnel" isn't supported under the ISR NIM switch module. I can't work out if that's a limitation of software or by design though?

[Giuseppe Larosa]

Hello,

the ISR switch module is actually built on hardware taken from a Cisco 2960 or a Cisco 3560 switch (depending on type of NIM).

For sure the lower end version that is derived from Cat 2960 does not support 802.1Q tunneling.

The other one might support it.

I have seen you have solved using a ME 3400 that is a good choice.

Hope to help

Giuseppe