KB.15.15

router pim bsr-candidate

Disables or re-enables the router for advertising itself as a Candidate-BSR on the

VLAN interface specified by source-ip-vlan [vid]. This command is used to

disable and re-enable BSR candidate operation after the bsr-candidate

source-ip-vlan [vid] command has been used to enable C-BSR operation

on the router. (This command operates only after the BSR source-ip-VLAN ID

has been configured.)

(Default: Disabled)

Changing the priority setting

Changing the priority setting for a BSR-candidate router.

Syntax:

bsr-candidate priority [0-255]

[no] router pim bsr-candidate priority [0-255]

Specifies the priority to apply to the router when a BSR election process occurs in

the PIM-SM domain. The candidate with the highest priority becomes the BSR for

the domain. If the highest priority is shared by multiple routers, the candidate having

the highest IP address becomes the domain's BSR. Zero (0) is the lowest priority.

To make BSR selection easily predictable, use this command to assign a different

priority to each candidate BSR in the PIM-SM domain.

(Default: 0; Range 0–255)

NOTE: Disabling PIM-SM on the elected BSR or disabling the C-BSR functionality

on the elected BSR causes the router to send a Bootstrap Message (BSM) with a

priority setting of 0 to trigger a new BSR election. If all BSRs in the domain are set

to the default priority (0), the election will fail because the result is to re-elect the

BSR that has become unavailable. For this reason, it is recommended that all C-BSRs

in the domain be configured with a bsr-candidate priority greater than 0.

Changing the distribution

Changing the distribution of multicast groups across a domain.

Syntax:

bsr-candidate hash-mask-length [1-32]

[no] router pim bsr-candidate hash-mask-length [1-32]

Controls distribution of multicast groups among the C-RPs in a domain where there

is overlapping coverage of the groups among the RPs. This value specifies the length

(number of significant bits) taken into account when allocating this distribution. A

longer hash-mask-length results in fewer multicast groups in each block of

group addresses assigned to the various RPs. Because multiple blocks of addresses

are typically assigned to each C-RP, this results in a wider dispersal of addresses

and enhances load-sharing of the multicast traffic of different groups being used in

the domain at the same time.

(Default: 30; Range 1–32)

Changing the message interval

Changing the BSR message interval.

Syntax:

bsr-candidate bsm-interval [5-300]

72 PIM-SM (Sparse Mode)