HP 6125XLG - Configuring a BSR

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The C-RPs periodically send advertisement messages to the BSR, which collects RP set information. You
can configure the interval for sending the advertisement messages.
The holdtime option in C-RP advertisement messages defines the C-RP lifetime for the advertising C-RP.
The BSR starts a holdtime timer for a C-RP after the BSR receives an advertisement message. If the BSR
does not receive any advertisement message when the timer expires, it regards the C-RP failed or
unreachable.
To guard against C-RP spoofing, configure a filtering policy on the BSR to define the legal C-RP address
range and the multicast group range to which the C-RP is designated. In addition, because every C-BSR
might become the BSR, you must configure the same filtering policy on all C-BSRs in the PIM-SM domain.
To configure a C-RP:
Ste
p
Command Remarks
1. Enter system view.
system-view
N/A
2. Enter PIM view.
pim [ vpn-instance vpn-instance-name ]
N/A
3. Configure a C-RP.
c-rp ip-address [ advertisement-interval
adv-interval | group-policy acl-number
| holdtime hold-time | priority priority ]
*
By default, no C-RP is
configured.
4. (Optional.) Configure a legal
C-RP address range and the
multicast group range to
which the C-RP is designated.
crp-policy acl-number
By default, no restrictions are
defined.
Configuring a BSR
You must configure a BSR if C-RPs are configured to dynamically select the RP. In a network with a static
RP, this configuration task is unnecessary.
A PIM-SM domain can have only one BSR, but must have at least one C-BSR. Any router can be
configured as a C-BSR. Elected from C-BSRs, the BSR is responsible for collecting and advertising RP
information in the PIM-SM domain.
Configuring a C-BSR
C-BSRs should be configured on routers on the backbone network. The BSR election process is
summarized as follows:
1. Initially, each C-BSR regards itself as the BSR of the PIM-SM domain and sends BSMs to other
routers in the domain.
2. When a C-BSR receives the BSM from another C-BSR, it compares its own priority with the priority
carried in the message. The C-BSR with a higher priority wins the BSR election. If a tie exists in the
priority, the C-BSR with a higher IP address wins. The loser uses the winner's BSR address to
replace its own BSR address and no longer regards itself as the BSR. The winner retains its own
BSR address and continues to regard itself as the BSR.
In a PIM-SM domain, the BSR does the following:
• Collects C-RP information from the received advertisement messages from the C-RPs.
• Encapsulates the C-RP information in the RP-set information.
• Distributes the RP-set information to all routers in the PIM-SM domain.