Configuring a VSX switch as root for one or more RPVST instances

Procedure
  1. For a single RPVST instance, enter for example: 
    switch(config)# spanning-tree vlan 1 priority 1
  2. For multiple RPVST instances, enter a range for example: 
    switch(config)# spanning-tree vlan 1-100 priority 1
    switch(config)# spanning-tree vlan 10,20,30 priority 1