339
Figure 93
RPT building at the receiver side
Source
Server A
Server B
Host B
Host C
Receiver
Receiver
IPv6 Multicast packets
Receiver-side RPT
Join message
RP
Source
Host A
Receiver
As shown in
, the process for building a receiver-side RPT is similar to that for building an RPT
in IPv6 PIM-SM:
1.
When a receiver joins IPv6 multicast group G, it uses an IGMP message to inform the directly
connected router.
2.
Upon getting the receiver information, the router sends a join message, which is forwarded hop by
hop to the RP of the IPv6 multicast group.
3.
The routers along the path from the receiver’s directly connected router to the RP form an RPT
branch, and each router on this branch adds a (*, G) entry to its forwarding table. The * means
any IPv6 multicast source.
When a receiver is no longer interested in the multicast data addressed to IPv6 multicast group G, the
directly connected router sends a prune message, which goes hop by hop along the reverse direction of
the RPT to the RP. Upon receiving the prune message, each upstream node deletes the interface
connected with the downstream node from the outgoing interface list and checks whether it has receivers
in that IPv6 multicast group. If not, the router continues to forward the prune message to its upstream
router.
Summary of Contents for A5500 EI Switch Series
Page 12: ...xii Conventions 425 Index 427 ...
