M-LAG (Multichassis Link Aggregation Group) is a key reliability technology in the Huawei Xinghe Intelligent Campus architecture. It provides device-level redundancy by virtualizing two switches into a single logical entity. One of the primary performance requirements for M-LAG in high-availability designs is ensuring millisecond-level failover. In the event of a single link failure (e.g., an uplink from an access switch to one of the M-LAG core switches), the traffic is rerouted through the peer-link or the remaining active member of the Eth-Trunk in less than 50 ms, ensuring 'hitless' service for sensitive applications like voice or industrial control.