[c-nsp] IP Q-in-Q Termination

[Tassos Chatzithomaoglou]

 From CCO (at least on SB IOS):


"A subinterface that is configured with multiple inner VLAN IDs is called an ambiguous Q-in-Q subinterface. By allowing multiple 
inner VLAN IDs to be grouped together, ambiguous Q-in-Q subinterfaces allow for a smaller configuration, improved memory usage, 
and better scalability."

"The any keyword in the second-dot1q command is not supported on a subinterface configured for IPoQ-in-Q because IP routing is not 
supported on ambiguous subinterfaces. Therefore, multiple values and ranges for the inner VLAN ID are not supported on IPoQ-in-Q."



--
Tassos

J Springer wrote on 20/8/2007 4:19 μμ:
> We are testing Q-in-Q termination with a 3660 router running 12.4(13c).
> 
> Config snippet:
> 
> interface FastEthernet0/1.14
>   encapsulation dot1Q 14 second-dot1q 33,66,99
>   ip address 192.168.1.1 255.255.255.0
> 
> 
> Monitoring traffic in both directions indicates that the inner and outer Vlan 
> tags are transitting to the router but the router only sends back traffic on the 
> first configured inner Vlan tag.
> 
> We would like to do (this doesn't work either):
> 
> interface FastEthernet0/1.14
>   encapsulation dot1Q 14 second-dot1q 1-4094
>   ip address 192.168.1.1 255.255.255.0
> 
> And I'd ultimately like to put this in a 7500.
> 
> Does this IOS support multiple inner Vlan tags?   And, is this configurable on 
> 3660 and 7500s?
>