Enabling Automatic LBDT
Context
The switch joins VLAN 1 by default, and the PVID of all interfaces is VLAN 1. When an interface changes from Down to Up, a loop may occur. You can configure automatic LBDT to detect loops in the VLAN specified by the PVID on an interface. When the switch is enabled with MAC address flapping detection, if MAC address flapping is detected in a VLAN, automatic LBDT is triggered to detect loops in the VLAN.
Procedure
- Run system-view
The system view is displayed.
- Run undo loopback-detect
auto disable
Automatic LBDT is enabled on all interfaces.
By default, automatic LBDT is enabled on all interfaces. When a loop is detected in the VLAN specified by the PVID on an interface, a trap is reported.
To disable automatic LBDT, run the loopback-detect auto disable command.
When the loopback-detect enable command is used to configure manual LBDT, automatic LBDT becomes invalid.
When the loopback-detect enable command is used to configure manual LBDT, automatic LBDT on the corresponding interface becomes invalid.
Follow-up Procedure
To enable LBDT triggered by MAC address flapping, first configure MAC address flapping detection. For details on how to configure MAC address flapping detection, see Configuring MAC Address Flapping Detection.
By default, global MAC address flapping detection is enabled. The switch detects MAC address flapping in all VLANs.
- trap: The interface only sends a trap.
- quitvlan: The interface is removed from the VLAN where a loop occurs.
You can run the loopback-detect auto action { quitvlan | trap } command in the system view to configure the action when automatic LBDT is triggered to automatically detect loops in the VLAN where MAC address flapping is detected.
By default, the action is trap when automatic LBDT is triggered to detect loops in the VLAN where MAC address flapping is detected.
The quitvlan action that is configured using this command takes effect only in the scenario where automatic LBDT is triggered to detect a loop between interfaces in the VLAN where MAC address flapping is detected. The trap action is used in the scenario where automatic LBDT is triggered to detect a loop on the downstream network or device in the VLAN where MAC address flapping is detected.