show spanning-tree root

Privileged EXEC Mode

Command Name

show spanning-tree root

Synopsis

This show spanning-tree root command provides information about the root bridge in the Spanning-Tree Protocol (STP) configuration on a network switch.

Description

The show spanning-tree root command is used to view details related to the root bridge of the Spanning-Tree topology. It can display various aspects such as the root bridge's address, cost, priority, and specific port information. This command is valuable for network administrators to understand the STP topology and the role of the current switch in relation to the root bridge.

Syntax

show spanning-tree root [{address | cost | forward-time | id | max-age | port | priority | detail}]

Parameters

• address: Displays the MAC address of the root bridge.

• cost: Shows the cost of the path from the current switch to the root bridge.

• forward-time: Indicates the forward delay time for the root bridge.

• id: Displays the identifier of the root bridge.

• max-age: Shows the maximum age of the root bridge information.

• port: Provides information about the port leading towards the root bridge.

• priority: Displays the priority of the root bridge.

• detail: Gives detailed information about the root bridge.

Options

N/A

Examples

• To display the address of the root bridge:

  show spanning-tree root address
  

• To view the cost to the root bridge:

  show spanning-tree root cost
  

• To check the priority of the root bridge:

  show spanning-tree root priority
  

• For detailed information about the root bridge:

  show spanning-tree root detail
  

Command Mode

Privileged EXEC Mode

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Summary

The show spanning-tree root command is essential for network professionals to assess the STP topology's root bridge configuration. It provides insights into how the current switch is connected to the root and the path characteristics such as cost and port information. Understanding the root bridge's details helps in network optimization, troubleshooting, and ensuring effective STP operation. When working in environments with multiple switches, the ability to specify a switch identifier is particularly useful to focus the output on a specific device, aiding in precise network analysis and management.