Depending on the switch vendor it may be also be referred to as PVST (per-vlan-spanning-tree.)
Dan Farrell Applied Innovations [EMAIL PROTECTED] -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Philip Guenther Sent: Tuesday, May 16, 2006 3:38 PM To: Raja Subramanian Cc: misc@openbsd.org Subject: Re: vlan router problems On 5/16/06, Raja Subramanian <[EMAIL PROTECTED]> wrote: ... > In my current setup it seems that my switch does not permit > the same MAC ID (of my router NIC) to appear on different > VLANs. So long as I have only one vlan interface up at any > given time, everything works perfectly. Right. The 802.1Q spec for ethernet vlans did not specify whether the spanning tree was per-VLAN or shared among them. As a result, many (most?) vendors just used a single tree, which breaks setups where the (active) port to use for a given device can vary by VLAN. Check the documentation, particularly the documentation for the firmware patches, for a configuration switch that enables something like "spanning tree per VLAN" and enable it. (I recall hitting this back in, uh, 1999 or so while working with a bunch of 3com switches at a previous job. 3com ended up releasing firmware upgrades that added such a configuration option, but man was it frustrating trying to figure out why it wasn't working. The doubly-connected device would only be able to see the first VLAN that it sent out on...) Philip Guenther
