ECS4660-28F_Management Guide-R03

C HAPTER 21 | Multicast Routing
Configuring PIM for IPv4
– 842 –
CONFIGURING A
PIM BSR CANDIDATE
Use the Routing Protocol > PIM > SM (BSR Candidate) page to configure
the switch as a Bootstrap Router (BSR) candidate.
CLI REFERENCES
◆ "ip pim bsr-candidate" on page 1938
COMMAND USAGE
◆ When this router is configured as a BSR candidate, it starts sending
bootstrap messages to all of its PIM-SM neighbors. The primary IP
address of the designated VLAN is sent as the candidate’s BSR address.
Each neighbor receiving the bootstrap message compares the BSR
address with the address from previous messages. If the current
address is the same or a higher address, it accepts the bootstrap
message and forwards it. Otherwise, it drops the message.
◆ This router will continue to be the BSR until it receives a bootstrap
message from another candidate with a higher priority (or a higher IP
address if the priorities are the same).
◆ To improve failover recovery, it is advisable to select at least two core
routers in diverse locations, each to serve as both a candidate BSR and
candidate RP. It is also preferable to set up one of these routers as both
the primary BSR and RP.
PARAMETERS
These parameters are displayed:
◆ BSR Candidate Status – Configures the switch as a Bootstrap Router
(BSR) candidate. (Default: Disabled)
◆ VLAN ID – Identifier of configured VLAN interface. (Range: 1-4094)
◆ Hash Mask Length – Hash mask length (in bits) used for RP selection
(see "Configuring a PIM Static Rendezvous Point" on page 843 and
"Configuring a PIM RP Candidate" on page 845). The portion of the
hash specified by the mask length is ANDed with the group address.
Therefore, when the hash function is executed on any BSR, all groups
with the same seed hash will be mapped to the same RP. If the mask
length is less than 32, then only the first portion of the hash is used,
and a single RP will be defined for multiple groups. (Range: 0-32;
Default: 10)
◆ Priority – Priority used by the candidate bootstrap router in the
election process. The BSR candidate with the largest priority is
preferred. If the priority values are the same, the candidate with the
larger IP address is elected to be the BSR. Setting the priority to zero
means that this router is not eligible to server as the BSR. At least one
router in the PIM-SM domain must be set to a value greater than zero.
(Range: 0-255; Default: 0)