Router PIM context commands for configuring PIM-SM operation

This section describes the commands used in the Router PIM context to:

Enable or disable SNMP trap status for PIM events (default: disabled)
Configure candidate BSR operation
Configure C-RP operation or the (optional) static RP operation


	NOTE: Before configuring BSR, RP, and SNMP trap operation for PIM-SM, it is necessary to enable PIM-SM on at least one VLAN on the router.

Configuring a BSR candidate

Selecting the VLAN interface to advertise as a BSR candidate.

Syntax:

[no]bsr-candidate source-ip-vlan [vid]
[no] router pim bsr-candidate source-ip-vlan [vid]

Configures the router to advertise itself as a candidate PIM-SM BSR on the VLAN interface specified by source-ip-vlan [vid], and enables BSR candidate operation. This makes the router eligible to be elected as the BSR for the PIM-SM domain in which it operates. Note that one BSR candidate VLAN interface is allowed per-router. The no form of the command deletes the BSR source IP VLAN configuration and also disables the router from being a BSR candidate, if this option has been enabled.(See the BSR-candidate command, below.)

Enabling or disabling a BSR Candidate

Enable or disable BSR candidate operation on a router.

Syntax:

[no] bsr-candidate
[no] 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]

[no] bsr-candidate bsm-interval [5-300]

Specifies the interval in seconds for sending periodic RP-Set messages on all PIM-SM interfaces on a router operating as the elected BSR in a domain.

NOTE: This setting must be smaller than the rp-candidate hold-time settings (range of 30 to 255; default 150) configured in the RPs operating in the domain.

(Default: 60; Range 5–300)

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	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.


	NOTE: This setting must be smaller than the `rp-candidate hold-time` settings (range of 30 to 255; default 150) configured in the RPs operating in the domain.