Pim-Sm Packets; Join/Prune Packets - HP 7102dl - ProCurve Secure Router Configuration Manual

Configuring Multicast Support with PIM-SM
Overview
N o t e
13-18
RP Set
Router A 244.0.0.0 7.255.255.255
Router B Any
Router A
Router C
Figure 13-7. Static RP Selection
Because you must configure exactly the same RP set on each router in the
domain, attempts to assign specific routers to specific groups can lead to
misconfigurations.

PIM-SM Packets

ProCurve Secure Routers exchange PIM-SM packets to:
build entries in their multicast routing tables
transition from an RP tree to an SP tree
eliminate redundant multicasts in multi-access networks
If you so desire, you can learn more about the mechanics of these processes
by reading about the various PIM-SM packets. Understanding basic informa-
tion about these packets will help you to troubleshoot PIM-SM.

Join/Prune Packets

All PIM routers send join/prune packets. Routers send join/prune packets out
the incoming interface for the group they want to join or leave. For RP tree
join/prunes, this is the interface that connects to the RP or the upstream RP
neighbor. For SP tree joins and prunes, this is the interface that connects to
the source or the upstream SP neighbor.
The join/prune packet includes one or more group entries. Each group entry
includes the group's multicast address, a join list, and a prune list. The join list
and the prune list consist of addresses, either for RPs or for multicast sources.
RP Set
Router A 244.0.0.0 7.255.255.255
Router B Any
RP Set
Router A 244.0.0.0 7.255.255.255
Router B Any
Router B