q-in-q router 0x8100

[erlangm]

Hi

I would like use the ethertype 0x8100 for the s-vlan tag.

i am using an 3845 Router.

example:

interface gig0/1

..

interface gig0/1.1

ip address x.x.x.x x.x.x.x

encapsulation dot1Q 500 second-dot1q 100

because its not possible to enter at the main-interface the command:

"dot1q tunneling ethertype 0x8100"

only ethertype 0x88a8 and 0x9100 is allowed!

so i ommited this command!

does this config work?

and which ethertype uses the router?

thanks

[ivillegas]

I have seen this command work with Cisco IOS XR software. http://www.cisco.com/en/US/docs/ios/12_0s/feature/guide/qinq.html

[erlangm]

thats right!

but the XR-Software isn't working with 3845 Router!

[Pavel Bykov]

By default Cisco uses 0x8100, which IANA assigned to 802.1Q.

0x88a8 and 0x9100 are not assigned by IANA.

See: http://www.iana.org/assignments/ethernet-numbers

Hope this helps.

[erlangm]

Hi

with infistream i could intercept the frames, which the router is sending into the lan.

so i can see now, that the frames are really double-tagged with ethertype 0x8100.

thanks