Relationship Among Pim Protocols - HP FlexFabric 5950 series Configuration Manual

Figure 53 SPT building in PIM-SSM
Source
Server
As shown in
their DRs to express their interest in the multicast information that the multicast source S sends to
the multicast group G.
After receiving a report message, the DR first checks whether the group address in this message is
in the SSM group range and does the following:
•
If the group address is in the SSM group range, the DR sends a subscribe message hop by hop
toward the multicast source S. All routers along the path from the DR to the source create an (S,
G) entry to build an SPT. The SPT is rooted at the multicast source S and has the receivers as
its leaves. This SPT is the transmission channel in PIM-SSM.
•
If the group address is not in the SSM group range, the receiver-side DR sends a (*, G) join
message to the RP. The multicast source registers with the source-side DR.
In PIM-SSM, the term "subscribe message" refers to a join message.

Relationship among PIM protocols

In a PIM network, PIM-DM cannot run together with PIM-SM, BIDIR-PIM, or PIM-SSM. However,
PIM-SM, BIDIR-PIM, and PIM-SSM can run together.
protocol from among them for a receiver trying to join a group.
For more information about IGMP SSM mapping, see "Configuring IGMP."
RP
SPT
Subscribe message
Multicast packets
Figure 53, Host B and Host C are receivers. They send IGMPv3 report messages to
DR
Figure 54
127
Host A
Receiver
DR
Host B
Receiver
Host C
shows how the device selects one