H3C S3610-28P Operation Manual page 825

Operation Manual – Multicast Protocol
H3C S3610&S5510 Series Ethernet Switches
hop towards DR 1 at the multicast source side, so that it can directly join the SPT
rooted at the source over other PIM-SM domains. Then, the multicast data can
flow along the SPT to RP 2 and is forwarded by RP 2 to the receivers along the
RPT. Upon receiving the multicast traffic, the DR at the receiver side (DR 2)
decides whether to initiate an RPT-to-SPT switchover process.
If no receivers for the group exist in the domain, RP 2 does dot create an (S, G)
entry and does join the SPT rooted at the source.
Note:
An MSDP mesh group refers to a group of MSDP peers that have MSDP peering
relationships among one another and share the same group name.
When using MSDP for inter-domain multicasting, once an RP receives information
form a multicast source, it no longer relies on RPs in other PIM-SM domains. The
receivers can override the RPs in other domains and directly join the multicast
source based SPT.
III. RPF check rules for SA messages
As shown in
through AS 5, with IGP enabled on routers within each AS and EBGP as the
interoperation protocol among different ASs. Each AS contains at least one PIM-SM
domain and each PIM-SM domain contains one ore more RPs. MSDP peering
relationships have been established among different RPs. RP 3, RP 4 and RP 5 are in
an MSDP mesh group. On RP 7, RP 6 is configured as its static RPF peer.
Note:
If only one MSDP peer exists in a PIM-SM domain, this PIM-SM domain is also called a
stub domain. For example, AS 4 in
stub domain can have multiple remote MSDP peers at the same time. You can
configure one or more remote MSDP peers as static RPF peers. When an RP receives
an SA message from a static RPF peer, the RP accepts the SA message and forwards
it to other peers without performing an RPF check.
Figure 7-3, there are five autonomous systems in the network, AS 1
7-5
Figure 7-3 is a stub domain. The MSDP peer in a
Chapter 7 MSDP Configuration