Configuring an Anycast RP in a PIM-SM Domain

Anycast RP indicates that when multiple RPs with the same address reside in the same PIM-SM domain and MSDP peer relationships are set up between these RPs, IP routing automatically selects the topologically closest RP for each source and receiver. In this manner, burdens on a single RP are released, RP backup is implemented, and the forwarding path is optimized.

Configuring the Interface Address of an RP: Before configuring anycast Rendezvous Point (RP) on the devices in a PIM-SM domain, configure a loopback interface on each device and assign the same IP address to the loopback interfaces. In addition, advertise the IP address of the RP through unicast routes to ensure that each device has a reachable route to the RP interface.

Configuring a C-RP: A loopback interface is configured as a Candidate-RP (C-RP) on the device to be configured with anycast Rendezvous Point (RP).

Statically Configuring an RP: To configure a static Rendezvous Point (RP), you need to configure the addresses of the loopback interfaces as the RP addresses on all the devices in a PIM-SM domain.

Configuring an MSDP Peer: MSDP peer relationships need be set up between RPs. If there are more than three devices, MSDP peer relationships should be set up between any two devices and all MSDP peers should be added to one mesh group.

Specifying the Logical RP Address for an SA Message: After receiving a Source Active (SA) message, an MSDP peer performs the Reverse Path Forwarding (RPF) check on the message. If the remote Rendezvous Point (RP) address carried in the SA message is the same as the local RP address, the MSDP peer discards the SA message. Therefore, you need to specify a logical RP address for SA messages on the device on which anycast RP is to be configured.