display stp abnormal-interface (All views)

Function

The display stp abnormal-interface command displays information about abnormal interfaces running the Spanning Tree Protocol (STP).

Format

display stp [ instance instance-id ] abnormal-interface

Parameters

Parameter	Description	Value
instance instance-id	Displays the status of and statistics about a specified spanning tree instance. If instance <instance-id> is not specified, the status of and statistics about all spanning tree instances will be displayed in the sequence of the interface numbers.	The value is an integer ranging from 0 to 4094, Value 0 indicates CIST.

Parameter

Description

Value

instance instance-id

Displays the status of and statistics about a specified spanning tree instance.

If instance <instance-id> is not specified, the status of and statistics about all spanning tree instances will be displayed in the sequence of the interface numbers.

The value is an integer ranging from 0 to 4094, Value 0 indicates CIST.

Views

All views

Default Level

1: Monitoring level

Task Name and Operations

Task Name	Operations
mstp	read

Usage Guidelines

Usage Scenario

If a device has many interfaces, querying information about abnormal STP interfaces by running the display stp command takes a long time.

To shorten the time, run the display stp abnormal-interface command.

Precautions

If you run this command in the MSTP process view without specifying an MSTP process, information about the MSTP process in this view is displayed by default. If you run this command in the other view without specifying an MSTP process, information about MSTP process 0 is displayed by default.

Example

The actual command output varies according to the device. The command output here is only an example.

# Display information about abnormal STP interfaces in instance 0.

<HUAWEI> display stp instance 0 abnormal-interface
MSTID    Interface                     Status          Reason                   
   0     GigabitEthernet0/1/8          DISCARDING      LOOP-Protected           
   0     GigabitEthernet0/1/9          DOWN            BPDU-Protected           
   0     GigabitEthernet0/1/10          DISCARDING      ROOT-Protected           
   0     GigabitEthernet0/1/11          DISCARDING      LOOP-Detected

**Table 1** Description of the **display stp abnormal-interface (All views)** command output
Item	Description
MSTID	MSTP instance ID.
Interface	Interface type.
Status	Status of an interface after the STP protection takes effect: DOWN: The physical status of the interface is Down (including error-down). DISCARDING: The interface is blocked after the topology of the spanning tree becomes stable.
Reason	An STP interface becomes abnormal due to one of the following: Root-Protected: The root protection takes effect. Loop-Protected: The loop protection takes effect. BPDU-Protected: The bridge protocol data unit (BPDU) protection takes effect. Loop-Detected: The ring detection takes effect.