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NOTE:
• For more information about DHCP snooping, see
Layer 3—IP Services Configuration Guide
.
• For more information about ARP snooping, see
Layer 3—IP Services Configuration Guide
.
• For more information about IP source guard, see the chapter “IP source guard configuration.”
• For more information about ARP detection, see the chapter “ARP attack protection configuration.”
• For more information about VLAN mappings, see
Layer 2—LAN Switching Configuration Guide
.
• An MFF-enabled device and a host cannot ping each other.
Basic concepts
A device with MFF enabled provides two types of ports: user port and network port.
User port
An MFF user port is directly connected to a host and processes the following packets differently:
• Allows DHCP packets and multicast packets to pass.
• Delivers ARP packets to the CPU.
• After learning gateways’ MAC addresses, a user port allows only the unicast packets with the
gateways’ MAC addresses as the destination MAC addresses to pass. If no gateways’ MAC
addresses are learned, a user port discards all received unicast packets.
Network port
An MFF network port is connected to a networking device, such as an access switch, a distribution switch
or a gateway. A network port processes the following packets differently:
• Allows multicast packets and DHCP packets to pass.
• Delivers ARP packets to the CPU.
• Denies broadcast packets.
NOTE:
• You need to configure the following ports as network ports: upstream ports connected to a gateway,
ports connected to the downstream MFF devices in a cascaded network (a network with multiple MFF
devices connected to one another), and ports between devices in a ring network.
• A network port is not always an upstream port.
• If you enable MFF for a VLAN, each port in the VLAN must be an MFF network or user port.
• Link aggregation is supported by network ports in an MFF-enabled VLAN, but is not supported by user
ports in the VLAN. You can add network ports to link a
re
ation
roups, but cannot add user ports to
link aggregation groups. For more information about link aggregation, see
Layer 2—LAN Switching
Configuration Guide
.
Operation modes
Manual mode
The manual mode applies to the case where IP addresses are statically assigned to the hosts, and the
hosts cannot obtain the gateway information through DHCP. A VLAN maintains only the MAC address
of the default gateway.