Verifying the Configuration of M-LAG Configured Through the Root Bridge

After M-LAG is configured, if the peer-link fails but the heartbeat status is normal, some interfaces on the backup device will enter the Error-Down state. The device records the status of an interface as Error-Down when it detects that a fault occurs. The interface in Error-Down state cannot receive or send packets and the interface indicator is off. You can run the display error-down recovery command to check information about all interfaces in Error-Down state on the device.

When M-LAG is used for dual-homing to an Ethernet, VXLAN network, or IP network and the peer-link fails but the heartbeat is normal, all physical interfaces except the management interface, peer-link interface, and stack interface on the backup device will enter the error-down state. When the peer-link recovers, the M-LAG interface in Error-Down state becomes Up after 240 seconds by default, and the physical interfaces in Error-Down state are restored to Up state.

When the interface enters the Error-Down state, locate the cause. You are not advised to manually restore the interface or run the error-down auto-recovery cause m-lag interval interval-value command in the system view to enable the interface to go Up automatically. Otherwise, packet loss or forwarding failure may occur. Exercise caution when you perform the preceding operation.