EVC adds and removes QinQ outer tag

[Yacine BS]

Hello,

Sorry but can't seem to find a good title for my question, you may help me with that.

I have, as posted in the image:

In my backbone, I have a PE that is connected to a switch (Switch 2). This switch has many clients connected to it and is performing QinQ tunneling for each one of them (Tags represented). The PE has VFI configured for each client ( VPLS ).

What I need to do is have the trafic go from site 1 to site 2 as follows:

           - From Client X Site 1 to ASR 2: trafic is tagged with the local Vlan id (each client has a BD for its VFI)

           -From ASR2 to ASR1: trafic is tunneled via the Virtual Circuit and no rewrite needed

           -From ASR 1 to Switch: trafic is forwarded with an additional tag ( QinQ tag ) based on the BD it came on and the encapsulation described on the EVC for that BD

           -From ASR1 to ASR2: trafic is forwarded through the virtual circuit while removing only the QinQ tag and keeping the local Vlan tag

What I reached so far is that I can recognise the trafic coming to ASR1 based on the QinQ outer tag, but once forwarded through the tunnel, the packet keeps its outer tag. And for compatibility reasons, I can't have the QinQ tag removed in the other site.

Please share with me how can I do this with EVCs or any other means,

Thanks,

[flettster]

Hi,

It looks like you just might need to pop the S-Tag on the relevant ASR1 service instances using:
rewrite ingress tag pop 1 symmetric

That should leave the C-Tag in place on the VFI. 

Do you have the config to show? 

Cheers.

[Yacine BS]

This is the config I tried:

interface GigabitEthernet2

description ### Link to Switch ###
no ip address
negotiation auto
dot1q tunneling ethertype 0x9100
no mop enabled
no mop sysid
service instance 228 ethernet
encapsulation dot1ad 228 dot1q 200
bridge-domain 2000
!
end

However, when I capture the packets going out of the ASR, they have the 228 tag which is the S-Vlan,