Enable Source Specific Multicast (SSM) to optimize PIM-SM by simplifying the many-to-many model (servers-to-receivers). Because most multicast applications distribute content to a group in one direction, SSM uses a one-to-many model that uses only a subset of the PIM-SM features. This model is more efficient and reduces the load on multicast routing devices.
Configure a unicast protocol, such as Routing Information Protocol (RIP) or Open Shortest Path First (OSPF), globally and on the interfaces where you want to configure PIM. For more information about RIP, see RIP configuration using EDM. For more information about OSPF, see OSPF configuration using EDM.
Enable PIM globally.
Important
After you enable PIM in SSM mode, the IGMP parameters take effect. To take full advantage of SSM, enable IGMPv3 if hosts that attach to the switch run IGMPv3 or configure the SSM table.
SSM is a global configuration. After you enable SSM on a switch, it is enabled on all interfaces that run PIM. On an SSM-enabled switch, SSM behavior is limited to the SSM group range. For non-SSM groups, the protocol behavior is PIM-SM.