[c-nsp] dot1q-tunneling

[Mikael Abrahamsson]

On Wed, 2 Aug 2006, Bill Wichers wrote:

> then you need the cisco-facing ports on the extreme to be trunk ports, or
> at least tagged with the correct VLAN. VLAN tags won't pass through

Just as a FYI, there is no such thing on an extreme switch as "trunk 
port". A vlan is configured to be tagged or untagged to a port or several 
ports. If it's not configured to the port or it's not created in the 
switch at all, any frames coming in on that port to a vlan that is not 
configured to be on that port, is dropped.

Imagine it as a cisco with a requirement to have all vlans as "switchport 
trunk allowed vlan" and then you have to list them all, at all times. 
Extreme also has a vlan-centric configuration, you create a vlan and add 
it to a port, instead of the cisco way where it's all port/interface 
based.

Coming from Extreme to Cisco, I prefer the Extreme way because it gives 
more control. I have noticed people used to Cisco coming to Extreme having 
the totally opposite view, they like the flexibility Cisco gives. Otoh 
we've more and more started to configure "switchport trunk allow vlan" to 
get this control, which makes it all even between the brands. With the 
added risk when it comes to cisco if you want to add a vlan to a trunkport 
and you forget the "add" statement, and hose all the other vlans on that 
trunkport.

-- 
Mikael Abrahamsson    email: swmike at swm.pp.se