118Configuring IGMP SSM mappingBecause of some possible restrictions, some receiver hosts on an SSM network might run IGMPv1 orIGMPv2. To provide SSM service support for these receiver hosts, configure the IGMP mapping featureon the last-hop router.Before you configure the IGMP SSM mapping feature, complete the following tasks:• Configure any unicast routing protocol so that all devices in the domain are interoperable at thenetwork layer.• Configure basic IGMP functions.Enabling SSM mappingStep Command Remarks1. Enter system view. system-view N/A2. Enter interface view. interface interface-typeinterface-number N/A3. Enable the IGMP SSMmapping feature. igmp ssm-mapping enable Disabled by defaultNOTE:To ensure SSM service for all hosts on a subnet, regardless of the IGMP version running on the hosts,enable IGMPv3 on the interface that forwards multicast traffic onto the subnet.Configuring SSM mappingsBy performing this configuration multiple times, you can map a multicast group to different multicastsources.If IGMPv3 is enabled on a VLAN interface of a switch, and if a port in that VLAN is configured as asimulated host, the simulated host will send IGMPv3 reports even if you did not specify a multicast sourcewhen you configure simulated joining with the igmp-snooping host-join command. In this case, thecorresponding multicast group will not be created based on the configured IGMP SSM mappings. Formore information about the igmp-snooping host-join command, see IP Multicast Command Reference.To configure an IGMP SSM mapping:Step Command Remarks1. Enter system view. system-view N/A2. Enter public networkIGMP view or VPNinstance IGMP view.igmp [ vpn-instance vpn-instance-name ] N/A3. Configure an IGMP SSMmapping.ssm-mapping group-address { mask |mask-length } source-addressNo IGMP mappings areconfigured by default.
