You can configure Source-Specific Multicast (SSM) mapping on the interface that connects the multicast device to the user network segment. This enables the user hosts that support only IGMPv1 or IGMPv2 but not IGMPv3 to join a specific source/group. In this manner, the multicast device running a later IGMP version is compatible with the hosts running an earlier IGMP version and can provide the SSM service for these hosts.
igmp [ vpn-instance vpn-instance-name ]
ssm-mapping group-address { mask | mask-length } source-address
To map a multicast group to multiple sources, run the command multiple times.
group-address { mask | mask-length } specifies the multicast group address and mask.
source-address specifies the address of the source to be mapped to the multicast group.