HPE 5820X Series, Руководство по настройке

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Figure 58 Where MSDP peers are in the network
As shown in Figure 58 , an MSDP peer can be created on any PIM-SM router. MSDP peers created
on PIM-SM routers that assume different roles function differently.
1.
MSDP peers on RPs include the following types:
{
Source-side MSDP peer
—The MSDP peer nearest to the multicast source (Source),
typically the source-side RP, like RP 1. The source-side RP creates SA messages and
sends the messages to its remote MSDP peer to notify the MSDP peer of the locally
registered multicast source information. A source-side MSDP peer must be created on the
source-side RP. Otherwise, it cannot advertise the multicast source information out of the
PIM-SM domain.
{
Receiver-side MSDP peer
—The MSDP peer nearest to the receivers, typically the
receiver-side RP, like RP 3. After receiving an SA message, the receiver-side MSDP peer
resolves the multicast source information carried in the message. Then, it joins the SPT
rooted at the source across the PIM-SM domain. When multicast data from the multicast
source arrives, the receiver-side MSDP peer forwards the data to the receivers along the
RPT.
{
Intermediate MSDP peer
—An MSDP peer with multicast remote MSDP peers, like RP 2.
An intermediate MSDP peer forwards SA messages received from one remote MSDP peer
to other remote MSDP peers. It acts as a relay of multicast source information.
2.
MSDP peers created on common PIM-SM routers (other than RPs):
Router A and Router B are MSDP peers on common multicast routers. Such MSDP peers just
forward received SA messages.
NOTE:
In a PIM-SM network using 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 relationship must be built among all C-RPs so that
the winner C-RP is always on the "MSDP interconnection map," and loser C-RPs assumes the role
of common PIM-SM routers on the "MSDP interconnection map."
Inter-domain multicast delivery through MSDP
As shown in Figure 59 , an active source (Source) exists in the domain PIM-SM 1, and RP 1 has
learned the existence of Source through multicast source registration. RPs in PIM-SM 2 and PIM-SM
3 also seek the specific location of Source so that receiver hosts can receive multicast traffic that the
source sends. MSDP peering relationship must be established between RP 1 and RP 3 and between
RP 3 and RP 2, respectively.