A RP is the focal point for multicast traffic. Traffic is forwarded to the RP from multicast sources. The RP then forwards traffic to multicast receivers.
Used with PIMSM Auto-RP and version 2. If the RPs fail, the router reverts to dense mode.
Two or more RPs are configured with the same IP address. The IP addresses of the RPs are advertised using a unicast IP routing protocol. Each multicast router chooses the closest RP. If an RP fails, the routers switch to the next nearest RP after the unicast IP routing protocol converges. The MSDP is used between RPs to exchange active multicast source information.