(Optional) Enabling Timed Gateway Address Detection

On a live network, services may be interrupted for a long time because the MFF-enabled device cannot immediately detect changes to the gateway MAC address. Timed gateway detection can solve this problem. With the timed gateway address detection function, which is enabled by default on all MFF-enabled devices, a device scans recorded gateway information within each interval. For each gateway recorded, the MFF-enabled device uses information about any user to construct an ARP request packet and sends it to the network interface. The MFF-enabled device then learns the gateway MAC address from the ARP reply packet. If the gateway MAC address has changed, the MFF-enabled device immediately updates the gateway information and broadcasts gratuitous ARP packets to user devices, so that user devices can update the gateway address.

If a gateway fails, traffic between users will be blocked. To avoid this situation, the device considers a gateway invalid if it does not receive a response from the gateway after five detection attempts. The device then deletes the MAC address entry of the invalid gateway. If the gateway detection interval is changed during a detection, the number of detection times is accumulated.