Catalyst5002> (enable) show spantree
VLAN 1
Spanning tree enabled
Spanning tree type ieee
Designated Root 00−00−80−0c−a1−b3
Designated Root Priority 32768
Designated Root Cost 0
Designated Root Port 1/0
Root Max Age 20 sec Hello Time 2 sec Forward Delay 15 sec
Bridge ID MAC ADDR 00−00−80−0c−a1−b3
Bridge ID Priority 32768
Bridge Max Age 20 sec Hello Time 2 sec Forward Delay 15 sec
Port Vlan Port−State Cost Priority Fast−Start Group−method
———————— ———— ———————————— ———— ———————— —————————— ————————————
1/1 1 not−connected 19 32 disabled
1/2 1 not−connected 19 32 disabled
2/1 1 forwarding 10 32 disabled
2/2 1 forwarding 10 32 disabled
2/3 1 forwarding 10 32 disabled
2/4 1 forwarding 10 32 disabled
2/5 1 forwarding 10 32 disabled
2/6 1 not−connected 19 32 disabled
2/7 1 forwarding 100 32 disabled
2/8 1 forwarding 100 32 disabled
2/9 1 not−connected 100 32 disabled
2/10 1 forwarding 10 32 disabled
2/11 1 forwarding 10 20 disabled
2/12 1 not−connected 19 32 disabled
2/13 1 forwarding 10 32 disabled
2/14 1 forwarding 10 32 disabled
2/15 1 forwarding 10 32 disabled
2/16 1 not−connected 19 32 disabled
2/17 1 forwarding 10 10 disabled
2/18 1 forwarding 10 32 disabled
2/19 1 not−connected 100 10 disabled
2/20 1 forwarding 10 32 disabled
2/21 1 forwarding 100 32 disabled
2/22 1 not−connected 100 32 disabled
2/23 1 forwarding 10 32 disabled
2/24 1 not−connected 100 32 disabled
Viewing the Spanning Tree Configuration on a CLI−Based IOS

The show spantree command can be used on a CLI−based IOS to obtain configuration information and

statistics on STP. Let’s take a look at the command, its optional syntaxes, and an example of its output:

show port <mod_num>
show port <mod_num/port_num>
1912EN#show spantree
VLAN1 is executing the IEEE compatible Spanning Tree Protocol
Bridge Identifier has priority 32768, address 0030.8054.6C00
Configured hello time 2, max age 20, forward delay 15
Current root has priority 32768, address 0000.0C00.4BD0
Root port is Ethernet 0/1, cost of root path is 100
Topology change flag not set, detected flag not set
Topology changes 0, last topology change occurred 0d00h00m00s ago
Times: hold 1, topology change 8960
hello 2, max age 20, forward delay 15
Timers: hello 2, topology change 35, notification 2

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