Spanning-tree modes: PVST vs RAPID-PVST

CanEHdian · ‎09-14-2006

I am upgrading an old network and as I add switches, I would like them to run rapid-pvst, instead of just pvst which is what the older switches are running.

Last I checked (with a Cisco techie at Networkers 2006), it was OK to have trunked switches with different modes (pvst and rapid-pvst)... but now I'm hearing differently from a few other sources.

Can someone please verify if this is a concern and if so, how should one proceed?

Cheers...

gpulos · ‎09-14-2006

rapid-pvst+ can be migrated into your pvst+ environment.

rapid-pvst+ configured switches revert to pvst+ to provide interoperability.

cisco recommends configuring the rapid-pvst+ and pvst+ for different STP instances. the rapid-pvst+ root switch must be running rapid-pvst+ and the pvst+ root switch must be running pvst+; as well, the pvst+ switches should be at the edge of the network.

(this being said, upgrade your core first and move outward. keep your pvst+ root switch out of the core where rapid-pvst+ will be running)

please see the following link for more info:

http://www.cisco.com/en/US/products/hw/switches/ps5206/products_configuration_guide_chapter09186a00801ce264.html#wp1150840