spanning-tree extend system-id question

[Eric Hansen]

I am curious how disruptive this command would be on a 6500vss that has several switches and several vlan's already running?  Every downlevel access switch is connected with a 2gig etherchannel, neighboring Core/Dist switches are 8gig etherchannels,  so a show span shows nothing but "Desg FWD".  So I am wondering if this command would set off a topology change event or not.

I am trying to kick vtp into v3, it wants this command.  The switch in question is a 24/7 switch, user impact is less than desireable.

-e

[IAN WHITMORE]

According to Cisco doucmentation:

When you enable or disable the extended system ID, the bridge IDs of all active STP instances are updated, which might change the spanning tree topology.

So I would plan an out-of-hours change just in case. It could cause STP to be recalculated.

HTH,

Ian

[Eric Hansen]

Yeah i am just hanging on that *might*.