Configuring IGMP SSM Mapping
Context
The source-specific multicast (SSM) model allows IGMPv3 hosts to specify the multicast sources which they want to receive data from. However, some hosts can only run IGMPv1 or IGMPv2. To enable these hosts to use the SSM service, configure IGMP SSM mapping on the switch. IGMP SSM mapping is implemented based on static SSM mapping entries on the switch. The switch converts (*, G) information in IGMPv1 and IGMPv2 Report messages to (S, G) information according to static SSM mapping entries to provide the SSM service for IGMPv1 and IGMPv2 hosts. By default, SSM group addresses range from 232.0.0.0 to 232.255.255.255. You can expand this range if required. For details, see (Optional) Configuring an SSM Group Policy.
Procedure
- Run system-view
The system view is displayed.
- Run interface interface-type interface-number
The interface view is displayed.
- (Optional) On an Ethernet interface, run undo portswitch
The interface is switched to Layer 3 mode.
By default, an Ethernet interface works in Layer 2 mode.
Only the S5720-EI, S5720-HI, S5730-HI, S5731-H, S5731-S, S5731S-H, S5731S-S, S5732-H, S6720-EI, S6720-HI, S6720S-EI, S6730-H, S6730S-H, S6730-S, and S6730S-S support switching between Layer 2 and Layer 3 modes.
- Run igmp ssm-mapping enable
IGMP SSM mapping is enabled on the interface.
By default, IGMP SSM mapping is disabled on an interface.
Enable IGMPv3 on switch interfaces to ensure that hosts running any IGMP version on a network segment can obtain the SSM service.
- Run quit
Return to the system view.
- Run igmp [ vpn-instance vpn-instance-name ]
The IGMP view is displayed.
- Run ssm-mapping group-address { group-mask | group-mask-length } source-address
An SSM mapping rule is configured to map a group address to a multicast source.
By default, no SSM mapping rule is configured.
Verifying the Configuration
Run the following commands in any view to check the configured mapping entries and whether IGMP SSM mapping is enabled on the interface.
- Run the display igmp group [ group-address | interface interface-type interface-number ]* ssm-mapping [ verbose ] command to check information about group memberships established with IGMP SSM mapping.
- Run the display igmp ssm-mapping { group [ group-address ] | interface [ interface-type interface-number ] } command to check SSM mapping entries configured and whether IGMP SSM mapping is enabled on an interface.