H3C Technologies H3C SecPath F1000-E - Manual (Page 171)

8
Embedded RP
The Embedded RP mechanism allows a router to resolve the RP address from an IPv6 multicast address
so that the IPv6 multicast group is mapped to an RP, which can take the place of the statically configured
RP or the RP dynamically calculated based on the BSR mechanism. The DR does not need to know the RP
address beforehand. The specific process is as follows.
• At the receiver side:
1. A receiver host initiates an MLD report to announce its joining an IPv6 multicast group.
2. Upon receiving the MLD report, the receiver-side DR resolves the RP address embedded in the IPv6
multicast address, and sends a join message to the RP.
• At the IPv6 multicast source side:
3. The IPv6 multicast source sends IPv6 multicast traffic to the IPv6 multicast group.
4. The source-side DR resolves the RP address embedded in the IPv6 multicast address, and sends a
register message to the RP.
RPT establishment
Figure 5 RPT establishment in an IPv6 PIM-SM domain
As shown in
Figure 5 , the process of building an RPT is as follows:
1. When a receiver joins IPv6 multicast group G, it uses an MLD report message to inform the directly
connected DR.
2. Upon getting the IPv6 multicast group G’s receiver information, the DR sends a join message,
which is hop by hop forwarded to the RP corresponding to the multicast group.
3. The routers along the path from the DR to the RP form an RPT branch. Each router on this branch
generates a (*, G) entry in its forwarding table. The * means any IPv6 multicast source. The RP is
the root, while the DRs are the leaves, of the RPT.
The IPv6 multicast data addressed to the IPv6 multicast group G flows through the RP, reaches the
corresponding DR along the established RPT, and finally is delivered to the receiver.