Configuring a root switch on IOS based Cisco switches

Contributed by Headhunter September 29, 2004  
Tagged: Cisco switch

When we use spanning tree a root switch is elected but when it comes to troubleshooting a switched network knowing where the root switch is makes it much easier. Another reason for “manually choosing” a root switch is that we can use our most powerfull switch to become the root.

To set the root switch for a particular VLAN is quite an easy task.
We use the following global configuration command:
Switch(config)#spanning-tree vlan vlan_id root primary

If we also want to manually set the backup root switch for the network we use the following command on our designated backup switch:
Switch(config)#spanning-tree vlan vlan_id root secondary

The vlan_id has to be the same in both command lines.