Most of my switches are running 12.2.25 or later. That version is capable of running Rapid Spanning Tree (802.1w). The show run says "spanning-tree mode pvst", and the show spanning-tree vlan 1 says "Spanning tree enabled protocol ieee". I have never changed the STP defaults. Am I running 802.1d or 802.1w? thanks. jc
>> If I attempt to move to RSTP on all my switches capable of running RSTP, what is the worst that can happen?
that the move will be not effective if most of the switches are still running PVST and so there is no real faster convergence.
So you have to evaluate how much is important for your network to improve STP convergence time.
If supporting VoIP the ability to have sub-second convergence can help.
Hope to help