Configuring MLD SSM Mapping
Context
The source-specific multicast (SSM) model allows MLDv2 hosts to specify the multicast sources from which they want to receive data. However, some hosts can only run MLDv1. To allow these hosts to use SSM, configure MLD SSM mapping on the switch. MLD SSM mapping is implemented based on static SSM mapping entries on the switch. The switch converts (*, G) information in MLDv1 Multicast Listener Report messages to (S, G) information according to static SSM mapping entries to provide the SSM service for MLDv1 hosts. By default, the range of IPv6 SSM group addresses is FF3x::/32, in which x cannot be 1 or 2. You can expand the range of IPv6 SSM group addresses. For the configuration, 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 mld ssm-mapping enable
SSM mapping is enabled on the interface.
To ensure that hosts running any MLD version on a network segment can obtain SSM services, it is recommended that you enable MLDv2 on switch interfaces.
- Run quit
Return to the system view.
- Run mld
The MLD view is displayed.
- Run ssm-mapping ipv6-group-address ipv6-group-mask-length ipv6-source-address
One or more multicast group addresses are mapped to a multicast source address.
Verifying the Configuration
After configuring MLD SSM mapping on an interface, run the following commands in any view to check the configured mapping entries and whether MLD SSM mapping is enabled on the interface.
- Run the display mld interface [ interface-type interface-number | up | down ] [ verbose ] command to check the MLD information on an interface.
- Run the display mld group [ ipv6-group-address | interface interface-type interface-number ]* ssm-mapping [ verbose ] command to check information about multicast group entries established with MLD SSM mapping.
- Run the display mld ssm-mapping { group [ ipv6-group-address ] | interface [ interface-type interface-number ] } command to check the configuration of MLD SSM mapping.