3Com Switch 8800 Configuration Guide Chapter 29 PIM-SM Configuration
29-5
At first, each candidate BSR considers itself as the BSR of the PIM-SM domain, and
sends Bootstrap message by taking the IP address of the interface as the BSR
address.
When receiving Bootstrap messages from other routers, the candidate BSR will
compare the BSR address of the newly received Bootstrap message with that of itself.
Comparison standards include priority and IP address. The bigger IP address is
considered better when the priority is the same. If the priority of the former is higher,
the candidate BSR will replace its BSR address and stop regarding itself as the BSR.
Otherwise, the candidate BSR will keep its BSR address and continue to regard itself
as the BSR.
Perform the following configuration in PIM view.
Table 29-2 Configuring candidate-BSRs
Operation Command
Configure a candidate-BSR c-bsr Vlan-interface Vlan-interface-number
hash-mask-len [ priority ]
Remove the candidate-BSR
configured undo c-bsr
Candidate-BSRs should be configured on the routers in the network backbone. By
default, no BSR is set. The default priority is 0.
Caution:
One router can only be configured with one candidate-BSR. When a candidate-BSR is
configured on another interface, it will replace the previous configuration.
In PIM-SM, the shared tree built by multicast routing data is rooted at the RP. There is a
mapping from a multicast group to an RP. A multicast group can be mappe d to only one
RP. Different multicast groups can be mapped to the same RP or different RPs.
Perform the following configuration in PIM view.
Table 29-3 Configuring candidate-RPs
Operation Command
Configure a candidate-RP c-rp interface-type interface-number [ group-policy
acl-number | priority priority-value ]*