Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. If you'd prefer to explore, try our test area to get started. And see here for current known issues.

New Member

Spanning-tree convergence times

As a temporary solution to a problem I'm about to propose that we use one 1GB link between our two sites. As a backup we would use 2X 100MG etherchannel. If the Gig link were to fail how long would it take RSTP to reconverge?

The switches are currently using pvst. To change to rpvst is it just a case of entering spanning-tree mode command and if so is there anything I need to be aware of.

Many Thanks


Re: Spanning-tree convergence times

For PVST you need to take in to conideration the timers suuch as by default Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec. If you are using backbonefast you can save a switch up to 20 seconds (max_age) when it recovers from an indirect link failure includding using uplink fast.

with RSTP these features are built in.

see this link for migration from pvst to rstp.

Re: Spanning-tree convergence times