Configuring Actions In Response to Layer 2 Loops

The CPU determines whether to enable or disable Layer 2 loop detection based on packet loss caused by the committed access rate (CAR). After Layer 2 loop detection is enabled, the CPU will take the configured actions in response to Layer 2 loops after the system detects an existing or a potential loop on an interface.

Context

The system can be configured to take one of the following actions in response to an existing or possible Layer 2 loop on an interface:

Shut down the interface: The system will shut down the interface only after detecting an existing Layer 2 loop on the interface. This action stops the interface from sending numerous packets to the CPU.
Send a trap: The system will send a trap after detecting an existing or a potential Layer 2 loop. The trap message can help a user locate the interface where the Layer 2 loop has occurred or may occur.
Send a trap and shut down the interface: The system will send a trap and shut down the interface after detecting an existing Layer 2 loop on the interface.
Ignore Layer 2 loops: The system will stop Layer 2 loop, but not shut down the interface or send a trap.

Procedure

Run system-view
The system view is displayed.
Run slot slot-id
The slot view is displayed.
Run l2-loop-detect action { shutdown [ up-times up-times | up-interval up-interval ] ^* | trap disable }
A responsive action for Layer 2 loops is configured.
- To enable the system to shut down the interface, run the l2-loop-detect action shutdown [ up-times up-times | up-interval up-interval ] ^* command.
- By default, the function of sending a trap is enabled. If the function is disabled, running the undo l2-loop-detect action trap disable command will enable it.
- To enable the system to send a trap and shut down the interface, run the undo l2-loop-detect action trap disable command to enable the function of sending a trap, and run the l2-loop-detect action shutdown [ up-times up-times | up-interval up-interval ] ^* command to enable the system to shut down the interface.
- To configure the system to ignore Layer 2 loops, run the undo l2-loop-detect action shutdown and l2-loop-detect action trap disable commands to disable the function of shutting down the interface and the function of sending a trap, respectively.
Run commit
The configuration is committed.