# Configuring SSM Mapping

SSM mapping enables the router to determine one or more source addresses for group G. The mapping effectively translates an MLDv1 multicast listener report to an MLDv2 report, enabling the router to continue as if it had initially received an MLDv2 report. After the router is joined to these groups, it sends out PIM join messages and continues to enable joining from these groups, as long as it continues to receive MLDv1 membership reports and no change occurs to the SSM mapping for the group.

When you statically configure SSM mapping, the router can discover source addresses from a statically configured table.

The following applies when you configure SSM mapping:

- When enabled, and either you have not configured a static SSM map or the router cannot find any matching access lists, the router continues to accept (*,G) groups. The PIM SSM range must deny any unacceptable SSM group addresses.
- When you issue the no ipv6 mld ssm-map enable command, the router removes all SSM map (S,G) states and establishes a (*,G) state.
- You can enter multiple ssm-map static commands for different access lists. Also, you can enter multiple ssm-map static commands for the same access list, as long as the access list uses different source addresses.
- SSM maps do not process statically configured groups.

ipv6 mld ssm-map enable

- Use to enable SSM mapping on the router. SSM mapping statically assigns sources to MLDv1 groups. You must use SSM mapping for MLDv1 hosts to interoperate with PIM SSM. SSM mapping allows the router use a statically configured list to translate (*,G) memberships to (S,G) memberships.
- Example
  host1:boston(config)#ipv6 mld ssm-map enable
- Use the no version to disable the SSM map.
- See ipv6 mld ssm-map enable.

ipv6 mld ssm-map static

- Use to specify an access list and source address for use in SSM mapping. SSM mapping statically assigns sources to MLDv1 groups. You must use SSM mapping for MLDv1 hosts to interoperate with PIM SSM. SSM mapping allows the router to use a statically configured list to translate (*,G) memberships to (S,G) memberships.
- The ipv6 mld ssm-map static command uses IPv6 access lists, which allow both source and destination/group addresses to be specified. You must set the source address to “ any.”
- Example
  host1:boston(config)#ipv6 mld ssm-map static boston-list 2001::1
- Use the no version to remove the SSM map association.
- See ipv6 mld ssm-map static.