[c-nsp] Q-in-Q frame sent into Q-in-Q tunnel

[Jon Harald Bøvre]

Hi

done some testing as we had problems with this some months ago.
QinQ tunnel 1 (transport vlan 5) - outer tunnel where customer are 
connected - STP,CDP (L2) forwarded
QinQ tunnel 2 (transport vlan 6) - inner SP tunnel where tunnel 1 should 
be transported - STP,CDP NOT L2 forwarded
No problem with this.

But if you configure inner SP tunnel with L2 forwarding there will be 
problems
QinQ tunnel 2 edge ports will see the encapsulated frames as invalid, 
and err-disable the port.

Solution:
-do not enable errdisable l2pt-guard on switches where SP tunnels are 
configured (probably undesired?)
or
-do not forward l2protocol on inner SP tunnel (customer will still have 
their STP,CDP forwarded)



Jon Harald Bøvre



On 10.02.2011 22:31, Stevan Zupanic wrote:
> Hello,
>
> As long as you adjust your switching MTU for 4 dot1q tags, things should
> work fine.  We have a customer who is doing Q-in-Q on in our Q-in-Q already.
> I believe (but don't quote me on this!) you can have up to 8 layer 2 dot1q
> tags at once.
>
>
> Stevan Zupanic
>
>
>
> -----Original Message-----
> From: cisco-nsp-bounces at puck.nether.net
> [mailto:cisco-nsp-bounces at puck.nether.net] On Behalf Of Jeff Fitzwater
> Sent: Thursday, February 10, 2011 3:01 PM
> To: cisco-nsp at puck.nether.net
> Subject: [c-nsp] Q-in-Q frame sent into Q-in-Q tunnel
>
>
>
>   I have an external customer which I need to tunnel across our network, but
> the traffic they are sending is QinQ  already;   Can I QinQ the traffic
> again so that I can control the VLAN ID ?
>
> Is my only concern the additional 4 bytes that I have to add to the MTU size
> in all the switches it propagates through?
>
>
>
> Thanks for any help.
>
>
>
>
> Jeff Fitzwater
> OIT Network Systems
> Princeton University
>
>
>
>
>
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