Configuring BSRs and RPs for PIM Sparse
After enabling PIM SM globally and locally, you need to identify an interface on
at least one device as a candidate PIM Sparse Bootstrap router (BSR) and candidate
PIM Sparse rendezvous point (RP).
Note: It is possible to configure the device as a candidate for either BSR or RP, but it
is recommended that you configure the same interface on the same device as both a
BSR and an RP.
- Enter global configuration mode.
- Globally enable PIM.
- Configure an interface as a candidate for BSR.
The hash number after the interface configuration specifies the number of bits in a group address that are significant when calculating the group-to-RP mapping. The hash value is from 1 through 32. It is recommended that you specify a value of 30 for IP version 4 (IPv4) networks. BSR priority can be configured as a value from 0 through 255. When the election process for BSR takes place, the candidate BSR with the highest priority becomes the BSR.
- Configure the device as a candidate RP.
By default, this command configures the device as a candidate RP for all group numbers beginning with 224. As a result, the device is a candidate RP for all valid PIM Sparse group numbers. You can change this by adding or deleting specific address ranges.
- (Optional) To add a group number range for which the device is a candidate RP, use
the
add option to explicitly add a range.
In this example, the device is a candidate RP for all groups that begin with 224.126. When you add a range, you override the default. The device then becomes a candidate RP only for the group address ranges you add.
- (Optional) To delete a group number range for which the device is a candidate RP,
use the
delete option to explicitly remove a range that was previously added.
This example deletes an address group from the devices for which it is a candidate RP.
The following example configures the PIM Sparse interface on port 1/2/2 as a BSR candidate, with a hash mask length of 30 and a priority of 255. The same interface is also configured as an RP candidate. An explicit group address range is configured and the device is now a candidate RP for prefixes starting with 224.126.
device# configure terminal device(config)# router pim device(config-pim-router)# bsr-candidate ethernet 1/2/2 30 255 device(config-pim-router)# rp-candidate ethernet 1/2/2 device(config-pim-router)# rp-candidate add 224.126.0.0 16