Subject: RE: VLAN tags?

From: Andrew Smith <[email-masked]>
Date: Thu, 8 Jul 1999 16:03:24 -0700

802.1Q VLANs are pretty common these days - most L3 switches and even some
routers support them now I think (and there are even some brave customers
who turn them on :-)). 

Maybe I don't understand enough about IS-IS but I'm not sure why you would
want to couple the L2 and L3 topologies like this unless you want to enforce
a 1:1 correspondance between IP subnets and VLANs. If the application is
just autoconfiguration of where the VLANs are to extend to then maybe look
at something like the 802.1Q GVRP protocol. If it's something cleverer then
I'd love to hear more about this idea from Radia.

Andrew Smith
Extreme Networks

-----Original Message-----
From: Hannes Gredler
To: [email-masked]
Cc: [email-masked]
Sent: 7/8/99 1:06 PM
Subject: Re: VLAN tags?

> One other thought. What about VLAN tag. Might it be useful when
> a bunch of routers are all connected to the same bridged topology,
> but that bridged topology is actually separated into a bunch
> of VLANs, to specify somewhere which VLAN this particular pseudonode
> is associated with? This would probably be a TLV only in the
pseudonode
> LSP.

radia,

in most vendors vlan implementation  a vlan has only switch-local
significance
(not 802.1Q) e.g. a given lan; on switch a the port to our lan may be in
vlan 10
and on switch b the port to the lan may be in vlan 20;

hardly to express this in the pseudonode lsp :-)

however, if you're talking about 802.1q you proposal would make sense.
(as the vlan tags are unique through the whole lan).

kind regards

Hannes Gredler

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