PIM in Source Specific Multicast operation uses information found on source addresses for a multicast group provided by receivers and performs source filtering on traffic.
- By default, PIM-SSM operates in the 232.0.0.0/8 multicast group range for IPv4 and ff3x::/32 (where x is any valid scope) in IPv6. To configure these values, use the ssm range command.
- If SSM is deployed in a network already configured for PIM-SM, only the last-hop routers must be upgraded with Cisco IOS XR software that supports the SSM feature.
- No MSDP SA messages within the SSM range are accepted, generated, or forwarded