How do I configure RSTP on Catalyst Switches.

Configuring RSTP

Running the RSTP on a Cisco switch is just a matter of a single command in global configuration mode:

sw#configure terminal

sw(config)#spanning-tree mode rapid-pvst

sw(config)#exit

RSTP

 But for overall configuration of RSTP we must need to configure all access ports as portfast.

(access ports - the ports towards end stations, notebooks, PCs, servers, network printers, etc.)

This will enable the ports to go straight to a forwarding state, meaning the ports will be up as soon as power is on.

For eg: go on switch and make the following command on every access port.

Example:

sw#configure terminal

sw(config)#interface fa0/3

(config-if)#spanning-tree portfast

(config-if)#exit

Lastly also, make sure that all your links are recognized as point-to-point (P2P) in the show spanning-tree output. RSTP is capable of rapid convergence only on point-to-point link types.

Verify, if RSTP is configured correctly.

To verify RSTP we can go through the configuration by using the show running-config command and verifying spanning-tree mode rapid-pvst has been entered on the switch.

The next command we can verify RSTP with is show spanning-tree, this will show what type of spanning-tree is enabled and root bridge/interface status.

Hope this was helpful.