Users Guide

NOTE: If you have enabled the override option, configuring static RP without using the override option does not
remove the override configuration. You must delete the static RP configuration using the override option and then
reconfigure static RP again.
To view the RP for a multicast group, use the show ip pim rp command.
OS10# show ip pim rp
Group RP
---------------------------------
225.1.1.1 171.1.1.1
225.1.1.2 171.1.1.1
225.1.1.3 171.1.1.1
225.1.1.4 171.1.1.1
225.1.1.5 171.1.1.1
225.1.1.6 171.1.1.1
To view the RP for a multicast group range, use the show ip pim rp mapping command.
OS10# show ip pim rp mapping
PIM Group-to-RP Mappings
Group(s): 230.1.1.1/32
RP:14.1.1.1, v2
Info source: 42.1.1.1, via bootstrap, priority 255
expires: 00:01:53
Group(s): 231.1.1.1/32
RP: 9.1.1.1, v2
Info source: 42.1.1.1, via bootstrap, priority 254
expires: 00:01:54
Configure dynamic RP using the BSR mechanism
You can configure a subset of PIM routers within the domain as candidate BSRs (C-BSRs). The C-BSRs exchange bootstrap
messages (BSM) to elect the BSR. The BSR informs its status to all the routers.
Every PIM router within a domain must map a particular multicast group address to the same RP. With BSR, group-to-RP
mapping is dynamic. You can configure a subset of routers within a domain as C-RPs. Each PIM router selects an RP for a
multicast group from the list of group-to-RP mappings learnt from the BSR messages.
The RP election process is:
1. The C-BSRs announce their candidacy throughout the domain in BSMs. Each BSM contains a BSR priority. The C-BSR with
the highest priority becomes the BSR.
2. Each C-RP unicasts periodic candidate RP advertisements to the BSR. Each message contains an RP priority value and the
multicast group ranges for which the router is a C-RP.
3. The BSR determines the most efficient and stable group-to-RP mapping, which is called the RP-set formation.
4. The BSR sends the group-to-RP mapping sets to all the multicast routers. To select an RP from a set of RPs, multicast
routers use the algorithm that is specified in RFC 4601.
5. The BSR sends the group range-to-RP mappings to all the routers in the domain.
Configuration notes
● A PIM router supports only one candidate BSR per VRF instance.
● A PIM router supports only one candidate RP per VRF instance.
● You can configure a PIM BSR candidate and an RP candidate with Layer 3 (L3) VLAN, Loopback, physical, or port channel
interface. The system derives the IP address from this interface to determine the BSR or RP address.
● PIM BSR and RP candidate configurations are not supported on VXLAN bridge interfaces.
● Before you configure a candidate BSR:
○ Enable multicast routing globally and establish PIM neighborship between routers. Ensure that the unicast routing table is
populated.
○ Configure an IP address on the candidate BSR interface.
● Before you configure a candidate RP:
802
Multicast