[c-nsp] Cisco and extreme .1q trunks

[Phil Mayers]

Phil Mayers wrote:
> Alex Foster wrote:
>> Currently experiencing issues building a .1q trunk between a 3550 and my
>> SPs black diamond switch... anybody had experience with interop'ing
>> these together.  The trunk comes up fine but we cant send traffic over
>> the VLANs on the trunk ?? 
> 
> Yes, they work fine.

By way of a slightly more verbose reply, here is such a configuration 
with just one untagged vlan (193) on it:

xx-c3550-1#sh run int g0/1
Building configuration...

Current configuration : 286 bytes
!
interface GigabitEthernet0/1
  description gi0/1: xx-extr-1 port 12
  switchport trunk encapsulation dot1q
  switchport trunk native vlan 193
  switchport trunk allowed vlan 193
  switchport mode trunk
  speed nonegotiate
end

We have similar configurations on 3750s and 6500s that push multiple 
vlans e.g. 4000 untagged, 4001-3 tagged

interface GigabitEthernet8/1
  description Summit5i
  switchport trunk encapsulation dot1q
  switchport trunk native vlan 4000
  switchport trunk allowed vlan 4000,4001,4002,4003
  switchport mode trunk
  speed nonegotiate
end

The equivalent config on the summit would be:

create vlan foo
conf foo tag 4000
conf foo ipaddress 10.40.0.1/24
conf foo add port X untagged

create vlan bar
conf bar tag 4001
conf bar ipaddress 10.40.1.1/24
conf bar add port X tagged

...but I guess you don't have access to that end.

Bear in mind that the Extremes can do cisco-compatible PVST (and also 
some weird and wonderful/awful other STP variants) so you might want to 
do "no span vlan XXX" or disable STP on that specific port.

> 
> What does a monitor session show you on the port?