Show & diagnostics
show spanning-tree
STP state: root bridge, port roles, port states.
Works on: SwitchMode: enable
Sample output
VLAN0001
Spanning tree enabled protocol rstp
Root ID Priority 32769
Address 0200.af22.3a9f
This bridge is the root
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Bridge ID Priority 32769 (priority 32768 sys-id-ext 1)
Address 0200.af22.3a9f
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 300 sec
Interface Role Sts Cost Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
VLAN0010
Spanning tree enabled protocol rstp
Root ID Priority 32778
Address 0200.af22.3a9f
This bridge is the root
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Bridge ID Priority 32778 (priority 32768 sys-id-ext 10)
Address 0200.af22.3a9f
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 300 sec
Interface Role Sts Cost Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Fa0/1 Desg FWD 19 128.Fa0/1 P2p Edge
Fa0/2 Desg FWD 19 128.Fa0/2 P2p Edge
Gi0/1 Desg FWD 4 128.Gi0/1 P2p Edge
VLAN0020
Spanning tree enabled protocol rstp
Root ID Priority 32788
Address 0200.af22.3a9f
This bridge is the root
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Truncated at 40 of 67 lines — run it in the lab for the full output.
Captured from the NetForge-AI simulator running a real topology.
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Frequently asked
What does the "show spanning-tree" command do?
STP state: root bridge, port roles, port states.