[c-nsp] Trunked links over EoMPLS

Sam Stickland sam_ml at spacething.org
Fri Nov 5 05:47:39 EST 2004


On Thu, 4 Nov 2004, McCallum, Robert wrote:

> Chris,  this is called QinQ.  However,  all that you can do is a dot1q trunk
> between the devices i.e. NO ISL.  ISL doesn't work (or at least didn't a
> week ago when we tested it).  If your switch is a 3550 the config looks like
> this.
>
>
> int fast0/1
> switchport dot1qtunnel
> switchport trunk allowed vlan blah blah blah.
> switchport access vlan xx (this is the vlan number for your network)
>
> you can then do l2protocol tunnel cdp,stp or vtp.  This command will allow
> total transparency.
>
>
> BTW if spanning tree is enabled for vlans then the customer shall see the
> vlan that you need to use to encapsulate their packets into.

Robert, could you elaborate on what you mean by this? It seems that you 
mean the customer will see the BDPUs for the vlan they are encapsulated 
into, but won't that cause problems? (STP will complain that the VLAN ids 
don't match).

Sam


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