Guidelines for Enabling or Disabling Egress Flooding

The following guidelines apply to enabling and disabling egress flooding:

• Egress flooding can be disabled on ports that are in a load-sharing group. In a load-sharing group, the ports in the group take on the egress flooding state of the master port; each member port of the load-sharing group has the same state as the master port.
• FDB learning takes place on ingress ports and is independent of egress flooding; either can be enabled or disabled independently.
• Disabling unicast (or all) egress flooding to a port also prevents the flooding of packets with unknown MAC addresses to that port.
• Disabling broadcast (or all) egress flooding to a port also prevents the flooding of broadcast packets to that port.
• For SummitStack and ExtremeSwitching series switches, the following guidelines apply:
  • You can enable or disable egress flooding for unicast, multicast, or broadcast MAC addresses, as well as for all packets on one or more ports.
  • Disabling multicasting egress flooding does not affect those packets within an IGMP membership group at all; those packets are still forwarded out.
  • If IGMP snooping is disabled, multicast packets with static FDB entries are forwarded according to the FDB entry.