To configure the router to be a statically connected member of the specified group on the interface, or to statically forward for a multicast group onto the interface, use the ip igmp static-group command in interface configuration mode. To remove the router as a member of the group, use the no form of this command.
ip igmp static-group {* | group-address [source {source-address | ssm-map}]}
no ip igmp static-group {* | group-address [source {source-address | ssm-map}]}
When you configure the ip igmp static-group command, packets to the group are fast-switched out the interface, provided that packets were received on the correct reverse path forwarding (RPF) interface.
Configuring the ip igmp static-group command is unlike configuring the ip igmp join-group command, which allows the router to join the multicast group. This configuration of the ip igmp static-group command would cause the upstream routers to maintain the multicast routing table information for that group, which would ensure that all the paths to that multicast group are active.