3Com 3C13636 Configuration Manual page 766

3Com Router 3000 Ethernet Family
Configuration Guide
send a join message to the node of a higher level toward the source S, which results in
switching from the RPT to the SPT.
II. Preparation before configuring PIM-SM
1) Configure Candidate-RPs
In a PIM-SM network, multiple Candidate-RPs (C-RPs) can be configured. Each C-RP
is responsible for forwarding multicast packets with the destination addresses in a
certain range, implementing RP load balancing. These C-RPs are equal. All multicast
routers calculate the RP for a connected multicast group by the same algorithm after
receiving the RP information reported by the BSR.
It should be noted that one RP can serve multiple or all multicast groups, while a
multicast group can have one RP at a time.
2) Configure BSR
BSR is the management kernel of the PIM-SM networks. It is responsible for collecting
and broadcasting the information sent by C-RPs.
There can be only one BSR in a network but multiple Candidate-BSRs (C-BSRs). In
this case, if the BSR fails, a candidate can assume its role by automatic election..
3) Configure static RP
RP is the kernel router for the multicast routing. If the dynamic RP elected by BSR
mechanism fails, a static RP can be configured. As the backup of dynamic RP, static RP
improves robustness and operability of the multicast network.
4.2 PIM-DM Configuration
Basic configuration tasks of PIM-DM include:
Enable Multicast
Enable IGMP on an interface
Enter PIM view
Enable PIM-DM
Advanced configuration tasks of PIM-DM include:
Configure the interval of Hello messages
Configure multicast source (group) policy
Configure PIM neighbor policy
Limit the number of PIM neighbors of an interface
4.2.1 Enabling Multicast
Refer back to the chapter "Common Multicast Configuration".
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Chapter 4 PIM Configuration