Users Guide
Electing an RP using the BSR Mechanism
Every PIM router within a domain must map a particular multicast group address to the same RP. The group-to-RP mapping may be
statically or dynamically congured. RFC 5059 species a dynamic, self-conguring method called the Bootstrap Router (BSR) mechanism,
by which an RP is elected from a pool of RP candidates (C-RPs).
Some routers within the domain are congured to be C-RPs. Other routers are congured to be Bootstrap Router candidates (C-BSRs);
one router is elected the BSR for the domain and the BSR is responsible for forwarding BSM containing RP-set information to other
routers.
The RP election process is as follows:
1 C-BSRs ood their candidacy throughout the domain in a BSM. Each message contains a BSR priority value, and the C-BSR with the
highest priority value becomes the BSR.
2 Each C-RP unicasts periodic Candidate-RP-Advertisements to the BSR. Each message contains an RP priority value and the group
ranges for which it is a C-RP.
3 The BSR determines the most ecient and stable group-to-RP mappings, which is called the RP-Set.
4 The BSR oods the RP-Set throughout the domain periodically in case new C-RPs are announced, or an RP failure occurs.
To enable RP election, perform the following steps:
1 Enter the following command to make a PIM router a BSR candidate:
CONFIGURATION
ip pim bsr-candidate
2 Enter the following command to make a PIM router a RP candidate:
CONFIGURATION
ip pim rp-candidate
3 Display Bootstrap Router information.
EXEC Privilege
show ip pim bsr-router
Enabling RP to Server Specic Multicast Groups
When you congure an RP candidate, its advertisement is sent to the entire multicast address range and the group-to-RP mapping is
advertised for the entire range of multicast address. Starting with Dell Networking OS 9.11.0.0, you can congure an RP candidate for a
specied range of multicast group address.
The Congured multicast group ranges are used by the BSR protocol to advertise the candidate RPs in the bootstrap messages.
You can congure the multicast group ranges as a standard ACL list of multicast prexes. You can then associate the congured group list
with the RP candidate.
NOTE
: • If there is no multicast group list congured for the RP-candidate, the RP candidate will be advertised for all the
multicast groups.
To enable an RP to serve specic group of multicast addresses, perform the following step:
Enter the following command to associate a multicast group to an RP candidate:
CONFIGURATION
PIM
Source-Specic Mode (PIM-SSM) 597