[c-nsp] Cat6500 VLAN cannot be assigned to a routed port sub-if?

[Peter Rathlev]

On Sat, 2016-09-17 at 14:24 +0200, Łukasz Bromirski wrote:
> > On 16 Sep 2016, at 17:32, Nick Cutting wrote:
> > Depends on supervisor - With sup 2t - you could reuse vlans on
> > subinterfaces, here is 2 subinterfaces on different ports, and an
> > SVI all on vlan 281
> > 
> > !
> > interface Vlan281
> > no ip address
> > shutdown
> > end
> > !
> > interface TenGigabitEthernet2/5/9.281
> > encapsulation dot1Q 281
> > end
> > !
> > interface TenGigabitEthernet2/5/8.281
> > encapsulation dot1Q 281
> > end
> 
> That’s actually config that will work with all Supervisors, wrong
> example :)

Nick is right, the config he showed would not work on Sup720 or
earlier. And it wouldn't matter if VTP was enabled or not. If the VLAN
exists "switched" then the first "encapsulation dot1q" command will be
rejected with "Command rejected: VLAN <N> already in use by interface
Vlan<N>". Trying to create more than two subinterfaces using the same
VLAN (on different interfaces of course) is rejected with "Command
rejected: VLAN <N> not available".

Sup2T doesn't have these problems.

> I understand Patrick is looking for a way to distinguish switched
> VLANs from routed VLANs, and indeed VLANs can be reused to forward
> different traffic with VLAN local significance on 6500/7600 starting
> from Sup2T.
> 
> For that (Patrick) needs bridge domains, so EVC infra - which is
> available on Sup2T with all ports, even with classical “LAN” cards -
> no SIPs needed.

I haven't played with it, but the implementation on Sup2T seems quite
limited. As a start you need to globally enable provider-bridge dot1ad
mode, which is incompatible with using LACP.

-- 
Peter