show spantree

Last Updated : Nov 06, 2012 |

Displays spanning-tree information. If no port is specified, information for all ports is displayed.

Syntax

show spantree [module[/port]]

Parameters

Parameter

Description

Possible Values

Default Value

module

Number of the module

port

Number of the port on the module

User level

read-only

Context

general

Example

To display spanning tree information for all ports:

Spanning tree state is enabled
Designated Root:  00-04-0d-ea-b0-2d
Designated Root Priority: 32768
Designated Root Cost: 0
Designated Root Port: No root port, Bridge is Designated root
Root Max Age: 20   Hello Time: 2
Root Forward Delay: 15
Bridge ID MAC ADDR: 00-04-0d-ea-b0-2d
Bridge ID priority: 32768
Bridge Max Age: 20        Bridge Hello Time: 2
Bridge Forward Delay: 15  Tx Hold Count 3
Spanning Tree Version is rapid spanning tree
Spanning Tree Default Path Costs is according to common spanning tree
Port   State         Cost       Priority
------ ------------- ---------- ------------
6/5 not-connected 4          128
10/6 not-connected 4          128

Output fields:

Field

Description

Spanning tree

Spanning-Tree Protocol status (enabled or disabled)

Designated root

MAC address of the designated spanning-tree root bridge

Designated Root Priority

Priority of the designated root bridge

Designated Root Cost

Total path cost to reach the root

Designated Root Port

Port through which the root bridge can be reached (shown only on non root bridges)

Root Max Age

Amount of time a BPDU packet should be considered valid

Hello Time

Number of times the root bridge sends BPDUs

Bridge ID MAC ADDR

Bridge MAC address used in the sent BPDUs

Bridge ID Priority

Bridge Priority

Port

Port number

State

Spanning-tree port state (disabled, inactive, not-connected, blocking, listening, learning, forwarding, bridging, or type-pvid-inconsistent)

Cost

Cost associated with the port

Priority

Priority associated with the port