Usage Scenario
L2VPN loop detection detects whether a loop exists between the AC interfaces of two PEs on a VPLS or VLL network to which a user network is dual homed. To prevent an AC interface from being unexpectedly blocked, run the loop-detection identifier command on the two PEs to configure the same identifier for them. After a PE receives a detection packet, it checks whether the identifier in the packet is the same as its local one. The PE considers the packet valid only when the identifiers are the same.
Prerequisites
L2VPN loop detection has been enabled globally using the loop-detection enable command.
Precautions
The loop-detection identifier command takes effect only for L2VPN loop detection.