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gateway's MAC address, the MFF device updates the MAC address upon receiving an ARP packet with
a different sender MAC address from the default gateway.
MFF working mechanism
Hosts connecting to an MFF device use the ARP fast-reply mechanism for Layer 3 communication. 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.
Protocols and standards
RFC 4562,
MAC-Forced Forwarding
Configuring MFF
Enabling MFF
To make MFF function in manual mode, enable ARP snooping on the device.
To enable MFF:
Step Command
Remarks
1.
Enter system view.
system-view
N/A
2.
Enter VLAN view.
vlan
vlan-id
N/A
3.
Enable MFF in manual mode
mac-forced-forwarding
default-gateway
gateway-ip
By default, MFF is disabled.
Configuring a network port
Step Command
Remarks
1.
Enter system view.
system-view
N/A