Adding an Interface to a Multicast Group

You can manually add an interface to a multicast group. This is useful in the following cases:

• Hosts attached to the interface are unable to add themselves as members of the group using IGMP.
• There are no members for the group attached to the interface.

When you manually add an interface to a multicast group, the device forwards multicast packets for the group but does not itself accept packets for the group.

You can manually add a multicast group to individual ports only. If the port is a member of a virtual routing and forwarding (VRF) interface, you must add the ports to the group individually.

To manually add a port 1/1/1 to multicast group 224.2.2.2:

device# configure terminal
device(config)# interface ethernet 1/1/1
device(config-if-e10000-1/1/1)# ip igmp static-group 224.2.2.2

To add a port 1/4/2 in VRF interface 1 to multicast group 224.2.2.2:

device# configure terminal
device(config)# interface ve 1
device(config-vif-1)# ip igmp static-group 224.2.2.2 ethernet 1/4/2

You can display information about manually added group using the following commands:

• show ip igmp group
• show ip pim group

To display static multicast groups in the default VRF, use the show ip igmp static command.

device# show ip igmp static

Group Address  Interface Port List
----------------------------------
    224.2.2.2  v1 ethe   1/4/2

To display information for IP PIM groups, use the show ip pim group command.

device> show ip pim group

Total number of groups for VRF default-vrf: 1
1    Group 224.2.2.2
     Group member at  e1/4/2