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New Member

Q-in-Q and Bridge Groups

I am trying to connect a router to a network that has double tagged ethernet (IP) packets. I have configured an ethernet subinterface to a bridge group and to the router via a BVI (see below). Double tagged packets are received from the network to the BVI but when a response is sent, it only has the outer tag and is ultimately dropped by the network.  If I change the setup to use single tags it all works, or if I change the setup to an IP addressed subinterface, not going through the bridge group it works. I cannot find documentation on such a setup using double tag termination and bridge/BVI. Does IOS support this combination?

interface FastEthernet0/1.1

encapsulation dot1Q 3001 second-dot1q 30
bridge-group 1
end

interface BVI1

ip address 10.24.205.1 255.255.255.0

end

Thanks

keith

2 REPLIES
Hall of Fame Super Silver

Re: Q-in-Q and Bridge Groups

Hello Keith,

what is the router platform and what IOS image is running on it?

some platforms support double vlan tag termination see like 10000

http://www.cisco.com/en/US/docs/routers/10000/10008/feature/guides/qinq.html

Hope to help

Giuseppe

New Member

Re: Q-in-Q and Bridge Groups

In my lab the equipment is  a Cisco IOS Software, 2800 Software with Version 12.4(24)T

In the large lab (same equipment as field), the issue is seen on a 7206 VXR also with 12.4.

In both cases, if the bridge group is removed and q-in-q terminates at the layer 3 interface (the GigE), it works fine. When the bridge group is added and the layer 3 is provided by the BVI, the problem occurs.

Thanks for your help.


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