Reference Guide

RPs by strategically mapping groups to RPs, but this technique is less effective as traffic increases because preemptive load
balancing requires prior knowledge of traffic distributions.
● lack of scalable register decasulation: With only a single RP per group, all joins are sent to that RP regardless of the
topological distance between the RP, sources, and receivers, and data is transmitted to the RP until the SPT switch
threshold is reached.
● slow convergence when an active RP fails: When you configure multiple RPs, there can be considerable convergence
delay involved in switching to the backup RP.
Anycast RP relieves these limitations by allowing multiple RPs per group, which can be distributed in a topologically significant
manner according to the locations of the sources and receivers.
1. All the RPs serving a given group are configured with an identical anycast address.
2. Sources then register with the topologically closest RP.
3. RPs use MSDP to peer with each other using a unique address.
Figure 86. MSDP with Anycast RP
Configuring Anycast RP
To configure anycast RP:
1. In each routing domain that has multiple RPs serving a group, create a Loopback interface on each RP serving the group
with the same IP address.
CONFIGURATION mode
interface loopback
2. Make this address the RP for the group.
494
Multicast Source Discovery Protocol (MSDP)