SW1(config)#spanning-tree vlan 10 root primary SW2(config)#spanning-tree vlan 20 root primary SW3(config)#interface fastEthernet 0/1 SW3(config-if)#spanning-tree vlan 20 cost 999 SW3(config-if)#interface fastEthernet 0/2 SW3(config-if)#spanning-tree vlan 10 cost 999 SW1(config)#spanning-tree mode rapid-pvst SW1(config)#spanning-tree mst configuration SW1(config-mst)#name Region1 SW1(config-mst)#revision 1 SW1(config-mst)#instance 1 vlan 101-150 SW1(config-mst)#instance 2 vlan 151-200 SW1(config)#spanning-tree mode mst SW1(config)#spanning-tree mst 1 root primary SW2(config)#spanning-tree mst 2 root primary SW3(config)#interface fastEthernet 0/1 SW3(config-if)#spanning-tree mst 2 cost 999 SW3(config-if)#interface fastEthernet 0/2 SW3(config-if)#spanning-tree mst 1 cost 999