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Configuring IGMP SSM mapping 
Because of some possible restrictions, some receiver hosts on an SSM network might run IGMPv1 or 
IGMPv2. To provide SSM service support for these receiver hosts, configure the IGMP mapping feature 
on 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 the 
network layer. 
•  Configure basic IGMP functions. 
Enabling SSM mapping 
 
Ste
 Command
Remarks
1.  Enter system view. 
system-view  N/A 
2.  Enter interface view. 
interface interface-type 
interface-number
 
N/A 
3.  Enable the IGMP SSM 
mapping feature. 
igmp ssm-mapping enable  Disabled by default 
 
  NOTE: 
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 mappings 
By performing this configuration multiple times, you can map a multicast group to different multicast 
sources. 
If IGMPv3 is enabled on a VLAN interface of a switch, and if a port in that VLAN is configured as a 
simulated host, the simulated host will send IGMPv3 reports even if you did not specify a multicast source 
when you configure simulated joining with the igmp-snooping host-join command. In this case, the 
corresponding multicast group will not be created based on the configured IGMP SSM mappings. For 
more information about the igmp-snooping host-join command, see IP Multicast Command Reference. 
To configure an IGMP SSM mapping: 
 
Ste
 Command
Remarks 
1.  Enter system view. 
system-view  N/A 
2.  Enter public network 
IGMP view or VPN 
instance IGMP view. 
igmp [ vpn-instance vpn-instance-name ]
N/A 
3.  Configure an IGMP SSM 
mapping. 
ssm-mapping group-address { mask | 
mask-length } source-address
 
No IGMP mappings are 
configured by default.