loopback-detection action

Use loopback-detection action to set the loop protection action on a per-port basis.

Use undo loopback-detection action to restore the default.

Syntax

In Layer 2 Ethernet interface view:

loopback-detection action { block | no-learning | shutdown }

undo loopback-detection action

In Layer 2 aggregate interface view:

loopback-detection action shutdown

undo loopback-detection action

Default

When the device detects a loop on a port, it generates a log but performs no action on the port.

Views

Layer 2 Ethernet interface view

Layer 2 aggregate interface view

Predefined user roles

network-admin

mdc-admin

Parameters

block: Enables the block mode. If a loop is detected, the device performs the following operations:

• Generates a log.

• Disables MAC address learning.

• Blocks the port.

Layer 2 aggregate interfaces do not support this keyword.

no-learning: Enables the no-learning mode. If a loop is detected, the device generates a log and disables MAC address learning on the port. Layer 2 aggregate interfaces do not support this keyword.

shutdown: Enables the shutdown mode. If a loop is detected, the device generates a log and shuts down the port. The device automatically sets the port to the forwarding state after the time interval set by using the shutdown-interval command (see Fundamentals Command Reference).

Usage guidelines

To set the loop protection action globally, use the loopback-detection global action command.

The global configuration applies to all ports. The per-port configuration applies to the individual ports. The per-port configuration takes precedence over the global configuration.

Example

# Set the loop protection action to shutdown on Ten-GigabitEthernet 1/0/1.

<Sysname> system-view
[Sysname] interface ten-gigabitethernet 1/0/1
[System-Ten-GigabitEthernet1/0/1] loopback-detection action shutdown

Related commands

display loopback-detection

loopback-detection global action