Chapter 1 Msdp Configuration; Msdp Overview; Introduction - H3C S9500 Series Operation Manual

Operation Manual – MSDP
H3C S9500 Series Routing Switches

Chapter 1 MSDP Configuration

When configuring MSDP, go to these sections for information you are interested in:

MSDP Overview

MSDP Configuration
Displaying and Maintaining MSDP
MSDP Configuration Examples
1.1 MSDP Overview

1.1.1 Introduction

No ISP would like to forward multicast traffic by RPs of competitors, but do expect to
obtain information from the source and distribute it among the members, regardless of
the location of the multicast source RP. MSDP is proposed to solve this problem.
Multicast source discovery protocol (MSDP) describes interconnection mechanism of
multiple PIM-SM domains. It is used is to discover multicast source information in other
PIM-SM domains. MSDP allows the RPs of different domains to share the multicast
source information, but all these domains must use PIM-SM as their intro-domain
multicast routing protocol.
A RP configured with MSDP peer notifies all of its MSDP peers of the active multicast
source message in its domain via a source active (SA) message. In this way, multicast
source information in a PIM-SM domain is transmitted to another PIM-SM domain.
MSDP peer relationship can be established between RPs in different domains or in a
domain, between a RP and a common router, or between common routers. The
connection between MSDP peers is a TCP connection.
MSDP makes a PIM-SM domain independent of the RP in another PIM-SM domain.
After getting multicast source information in that domain, the receiver here can join
directly to the SPT of the multicast source in that domain.
Another application of MSDP is Anycast RP. In a domain, configure a certain interface
(usually Loopback interface) on different routers with the same IP address; designate
these interfaces as C-RPs; and create MSDP peer relationship among them. After the
unicast route convergence, the multicast source can select the nearest RP for
registration, and the receiver can also select the nearest RP to add into its RPT. The
RPs exchange individual registration source information via MSDP peers. Therefore,
every RP knows all multicast sources of the entire domain; and every receiver on each
RP can receive multicast data from all the multicast sources in the entire domain.
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Chapter 1 MSDP Configuration