MAC address table static multicast entry

It is possible to statically assign a multicast MAC address to the MAC address table. This can be done by simply using the same command as you would would use for a unicast MAC address.

An example of how to achieve this can be seen below:

SW1(config)#mac address-table static 0100.5e00.1010 vlan 1 interface fastEthernet 0/1

The above command statically assigns the multicast MAC address of 01:00:5E:00:10:10 to the MAC address table.

It is important to note that adding a static multicast MAC address table entry manually will not be affected by IGMP snooping, as the static entry will remain in the table regardless of IGMP messages. However, you should be cautious when manually configuring multicast MAC address table entries, as it can interfere with the automatic operation of IGMP snooping and may cause unexpected results.

Unless there is a very good reason for it, and unless it’s done very carefully, it’s usually best practice to allow IGMP snooping to optimize multicast traffic forwarding in the network.

To find out more about IPv4 and IPv6 multicast MAC addresses, take a look at this Multicast MAC addresses note.