MFF working mechanism
An MFF-enabled device implements Layer 3 communication between hosts by intercepting ARP requests from the hosts and replies with the MAC address of a gateway. This mechanism helps reduce the number of broadcast messages.
The MFF device processes ARP packets as follows:
After receiving an ARP request from a host, the MFF device sends the MAC address of the corresponding gateway to the host. In this way, hosts in the network have to communicate at Layer 3 through a gateway.
After receiving an ARP request from a gateway, the MFF device sends the requested host's MAC address to the gateway if the corresponding entry is available. If the entry is not available, the MFF device forwards the ARP request.
The MFF device forwards ARP replies between hosts and gateways.
If the source MAC addresses of ARP requests from gateways are different from those recorded, the MFF device updates and broadcasts the IP and MAC addresses of the gateways.