H3C S5600 Series Operation Manual page 522

Operation Manual – Multicast
H3C S5600 Series Ethernet Switches
RP 1
(1)
RP 2
Figure 5-3 Diagram for RPF check for SA messages
As illustrated in
the following RPF check rules:
1) When RP 2 receives an SA message from RP 1
Because the source-side RP address carried in the SA message is the same as the
MSDP peer address, which means that the MSDP peer where the SA is from is the RP
that has created the SA message, RP 2 accepts the SA message and forwards it to its
other MSDP peer (RP 3).
2) When RP 3 receives the SA message from RP 2
Because the SA message is from an MSDP peer (RP 2) in the same AS, and the MSDP
peer is the next hop on the optimal path to the source-side RP, RP 3 accepts the
message and forwards it to other peers (RP 4 and RP 5).
3) When RP 4 and RP 5 receive the SA message from RP 3
Because the SA message is from an MSDP peer (RP 3) in the same mesh group, RP 4
and RP 5 both accept the SA message, but they do not forward the message to other
members in the mesh group; instead, they forward it to other MSDP peers (RP 6 in this
example) out of the mesh group.
4) When RP 6 receives the SA messages from RP 4 and RP 5 (suppose RP 5 has a
higher IP address)
Although RP 4 and RP 5 are in the same SA (AS 3) and both are MSDP peers of RP 6,
because RP 5 has a higher IP address, RP 6 accepts only the SA message from RP 5.
5) When RP 7 receives the SA message from RP 6
Because the SA message is from a static RPF peer (RP 6), RP 7 accepts the SA
message and forwards it to other peer (RP 8).
6) When RP 8 receives the SA message from RP 7
Source
AS 1
(3)
(2)
Mesh group
RP 3
AS 2 (3)
MSDP peers
Static RPF peers
SA message
Figure 5-3, these MSDP peers dispose of SA messages according to
RP 5 RP 9
(4)
AS 3
(4)
RP 4 RP 6
5-6
Chapter 5 MSDP Configuration
RP 8
(7)
AS 5
(6)
(5)
RP 7
AS 4