Enabling L2VPN Loop Detection on an AC Interface

Context

To prevent loops on an L2VPN network, you can configure L2VPN loop detection on an AC interface of the PE. After this function is enabled, when detecting a loop on the L2VPN network, the PE will automatically block an interface on the loop, report an alarm, and eliminate the loop.

Perform the following operations on the PE.

Procedure

Run system-view
The system view is displayed.
Run interface interface-type interface-number
The interface view is displayed.
(Optional) On an Ethernet interface, run undo portswitch
The interface is switched to Layer 3 mode.

By default, an Ethernet interface works in Layer 2 mode.

Only the S5720-EI, S5720-HI, S5730-HI, S5731-H, S5731-S, S5731S-H, S5731S-S, S5732-H, S6720-EI, S6720-HI, S6720S-EI, S6730-H, S6730S-H, S6730-S, and S6730S-S support switching between Layer 2 and Layer 3 modes.
Run loop-detect enable
L2VPN loop detection is enabled on the interface.

By default, L2VPN loop detection is disabled on the interface.
- The interface must be an AC interface bound to a specified VSI. For details about the binding between an AC interface and a VSI, see Binding VSIs to AC Interfaces.
- VSI encapsulation must use the VLAN encapsulation format that meets the 802.1Q standard. For details about how to configure the VSI encapsulation mode, see encapsulation (VSI view).