132Port status auto recoveryWhen the loop protection action block or no-learning is used, if the switch receives no loop detectionframe three loop detection intervals after a loop is detected on a port, the switch automatically sets theport to the forwarding state, and the switch notifies the user of the event.When the loop protection action shutdown is used, the switch automatically shuts down a port upondetecting a loop on the port. After the detection timer set by using the shutdown-interval commandexpires, the switch automatically brings up the port. The process is repeated until the loop is removed.NOTE:Incorrect recovery can occur when loop detection frames are discarded to reduce the load. To avoid thisproblem, use the shutdown action or manually remove the loop.Loop detection configuration task listTasks at a glance(Required.) Enabling loop detection(Optional.) Configuring the loop protection action(Optional.) Setting the loop detection intervalEnabling loop detectionYou can enable loop detection globally or on specific ports. The global configuration applies to all portsin the specified VLAN. The per-port configuration applies to the individual port only when the portbelongs to the specified VLAN. Per-port configurations take precedence over global configurations.H3C recommends not enabling loop detection on TRILL ports, because TRILL networks prevent loops frombeing generated. For information more about TRILL, see TRILL Configuration Guide.Enabling loop detection globallyStep Command Remarks1. Enter system view. system-view N/A2. Globally enable loopdetection.loopback-detection global enablevlan { vlan-list | all } Disabled by default.Enabling loop detection on a portStep Command Remarks1. Enter system view. system-view N/A
