H3C Technologies H3C S10500 Series Switches - Manual (Page 393)

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Configuring C-RP timers globally
To enable the BSR to distribute the RP-set information within the IPv6 PIM-SM domain, C-RPs must
periodically send C-RP-Adv messages to the BSR. The BSR obtains the RP-set information from the received
messages, and encapsulates its own IPv6 address together with the RP-set information in its bootstrap
messages. The BSR then floods the bootstrap messages to all IPv6 routers in the network.
Each C-RP encapsulates a timeout value in its C-RP-Adv messages. After receiving a C-RP-Adv message,
the BSR obtains this timeout value and starts a C-RP timeout timer. If the BSR fails to obtain a subsequent
C-RP-Adv message from the C-RP when the timer times out, the BSR assumes the C-RP to have expired or
become unreachable.
You must configure the C-RP timers on C-RP routers.
Follow these steps to configure C-RP timers globally:
To do... Use the command... Remarks
Enter system view system-view —
Enter IPv6 PIM view pim ipv6 —
Configure the C-RP-Adv interval c-rp advertisement-interval interval
Optional
60 seconds by default
Configure C-RP timeout time c-rp holdtime interval
Optional
150 seconds by default
NOTE:
For more information about the configuration of other timers in IPv6 PIM-SM, see “ Configuring IPv6 PIM
common timers .”
Configuring a BSR
An IPv6 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 IPv6 PIM-SM domain.
Configuring a C-BSR
You should configure C-BSRs on routers in the backbone network. When you configure a router as a
C-BSR, be sure to specify the IPv6 address of an IPv6 PIM-SM-enabled interface on the router. The BSR
election process is as follows:
• Initially, every C-BSR assumes itself to be the BSR of this IPv6 PIM-SM domain and uses its interface
IPv6 address as the BSR address to send bootstrap messages.
• When a C-BSR receives the bootstrap message of another C-BSR, it first compares its own priority
with the other C-BSR’s priority carried in the message. The C-BSR with a higher priority wins. If a tie
exists in the priority, the C-BSR with a higher IPv6 address wins. The loser uses the winner’s BSR
address to replace its own BSR address and no longer assumes itself to be the BSR, and the winner
keeps its own BSR address and continues assuming itself to be the BSR.
Configuring a legal range of BSR addresses enables filtering of bootstrap messages based on the
address range, thereby preventing a maliciously configured host from masquerading as a BSR. You must
make the same configuration on all routers in the IPv6 PIM-SM domain. Typical BSR spoofing cases and
the corresponding preventive measures are as follows: