HP MSR1002-4 Configuration Manual page 338

As shown in
messages) to the BSR. An advertisement message contains the address of the advertising C-RP
and the IPv6 multicast group range to which it is designated. The BSR collects these advertisement
messages and organizes the C-RP information into an RP-set, which is a database of mappings
between IPv6 multicast groups and RPs. The BSR encapsulates the RP-set information in the
bootstrap messages (BSMs) and floods the BSMs to the entire IPv6 PIM-SM domain.
Figure 94 Information exchange between C-RPs and BSR
Bootstrap message
Advertisement message
Based on the information in the RP-set, all routers on the network can select an RP for a specific
IPv6 multicast group based on the following rules:
1. The C-RP that is designated to the smallest IPv6 multicast group range wins.
2. If the C-RPs are designated to the same IPv6 multicast group range, the C-RP with the highest
priority wins.
3. If C-RPs have the same priority, the C-RP with the largest hash value wins. The hash value is
calculated through the hash algorithm.
4. If the C-RPs have the same priority and hash value, the C-RP with the highest IPv6 address
wins.
Embedded RP
The embedded RP mechanism enables a router to resolve the RP address from an IPv6 multicast
group address to map the IPv6 multicast group to an RP. This RP can take the place of the
configured static RP or the RP dynamically elected by the bootstrap mechanism. A DR does not
need to learn the RP address beforehand. The process is as follows:
•
At the receiver side:
a. A receiver host initiates an MLD report to express its interest in an IPv6 multicast group.
b. After receiving the MLD report, the receiver-side DR resolves the RP address embedded in
the IPv6 multicast group address and sends a join message to the RP.
•
At the IPv6 multicast source side:
c. The IPv6 multicast source sends IPv6 multicast traffic to an IPv6 multicast group.
d. The source-side DR resolves the RP address embedded in the IPv6 multicast address, and
sends a register message to the RP.
Anycast RP
IPv6 PIM-SM requires only one active RP to serve each IPv6 multicast group. If the active RP fails,
the multicast traffic might be interrupted. The Anycast RP mechanism enables redundancy backup
among RPs by configuring multiple RPs with the same IPv6 address for one multicast group. An IPv6
Figure 94, each C-RP periodically unicasts its advertisement messages (C-RP-Adv
IPv6 PIM-SM
C-RP
BSR
C-RP
C-BSR
C-RP
329