HP 4500G PWR 24-Port, Руководство по настройке

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1-3
Router A and Router B are MSDP peers on common multicast routers. Such MSDP peers just forward
received SA messages.
In a PIM-SM network running the BSR mechanism, the RP is dynamically elected from C-RPs. To
enhance network robustness, a PIM-SM network typically has more than one C-RP. As the RP election
result is unpredictable, MSDP peering relationships should be built among all C-RPs so that the winner
C-RP is always on the "MSDP interconnection map”, while loser C-RPs will assume the role of common
PIM-SM routers on the “MSDP interconnection map”.
Implementing inter-domain multicast delivery by leveraging MSDP peers
As shown in Figure 1-2 , an active source (Source) exists in the domain PIM-SM 1, and RP 1 has
learned the existence of Source through multicast source registration. If RPs in PIM-SM 2 and PIM-SM
3 also wish to know the specific location of Source so that receiver hosts can receive multicast traffic
originated from it, MSDP peering relationships should be established between RP 1 and RP 3 and
between RP 3 and RP 2 respectively.
Figure 1-2
MSDP peering relationships
RP 1
DR 1
Source
PIM-SM 1
PIM-SM 3
PIM-SM 2
PIM-SM 4
RP 3
RP 2
DR 2
MSDP peers
SA message
Join message
Multicast packets
Register message
Receiver
The process of implementing inter-domain multicast delivery by leveraging MSDP peers is as follows:
1) When the multicast source in PIM-SM 1 sends the first multicast packet to multicast group G, DR 1
encapsulates the multicast data within a register message and sends the register message to RP 1.
Then, RP 1 gets aware of the information related to the multicast source.
2) As the source-side RP, RP 1 creates SA messages and periodically sends the SA messages to its
MSDP peer. An SA message contains the source address (S), the multicast group address (G),
and the address of the RP which has created this SA message (namely RP 1).