4000 Router Series IP Multicast Configuration Guide

BSR encapsulates the RP-set information in the bootstrap messages (BSMs) and floods the BSMs to the

entire PIM-SM domain.

Figure 27 Information exchange between C-RPs and BSR

Based on the information in the RP-set, all routers in the network can select the proper RP for a specific

multicast group based on the following rules:

1. The C-RP that is designated to a smaller group range wins.

2. If the group ranges are the same, the C-RP with the highest priority wins.

3. If all the C-RPs have the same priority, the C-RP with the largest hash value (calculated through the

hash algorithm) wins.

4. If all the C-RPs have the same hash value, the C-RP with the highest IP address wins.

RPT building

Figure 28 RPT building in a PIM-SM domain

As shown in Figure 28, the process of building an RPT is as follows:

Source

Server

Host A

Host B

Host C

Receiver

Multicast packets

RPT

Join message

RP DR