Hi Carl,
When you do the " Show spanning-tree detail" on the switch, it will show the root swithc ID and its priority.
Once you do the " show spanning-tree detail" on the root switch, this will show you the same mac-address on the switch. There is not other method which will automatically tell you that which switch is the root switch. You have to do this manually on each switch. That's why when we set up the network for the first time, we define that which switch will be primary root switch adn which one will be the secondry root switch on the network. This will give us a total view of the L2 network topology.
Switch# show spanning-tree detail
VLAN0001 is executing the ieee compatible Spanning Tree protocol
Bridge Identifier has priority 49152, sysid 1, address 0003.fd63.9580
Configured hello time 2, max age 20, forward delay 15
Current root has priority 32768, address 0001.42e2.cdd0
Root port is 24 (GigabitEthernet0/1), cost of root path is 3038
Topology change flag not set, detected flag not set
Number of topology changes 0 last change occurred 1d16h ago
Times: hold 1, topology change 35, notification 2
hello 2, max age 20, forward delay 15
Timers: hello 0, topology change 0, notification 0, aging 300
Uplinkfast enabled
Port 1 (GigabitEthernet0/1) of VLAN0001 is forwarding
Port path cost 3019, Port priority 128, Port Identifier 128.24.
Designated root has priority 32768, address 0001.42e2.cdd0
Designated bridge has priority 32768, address 00d0.bbf5.c680
Designated port id is 128.25, designated path cost 19
Timers: message age 2, forward delay 0, hold 0
Number of transitions to forwarding state: 1
Link type is point-to-point by default
BPDU: sent 0, received 72364
HTH,Please rate if it does.
-amit singh
