3Com 4800G Series, Configuration Manual

Page: 673 / 1246

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MSDP C
ONFIGURATION
When configuring MSDP, go to these sections for information you are interested
in:
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“MSDP Overview” on page 673
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“MSDP Configuration Task List” on page 679 * MERGEFORMAT
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“Displaying and Maintaining MSDP” on page 685
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“MSDP Configuration Examples” on page 685
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“Troubleshooting MSDP” on page 697
n
The term “router” in this document refers to a router in a generic sense or a Layer
3 switch running the MSDP protocol.
MSDP Overview
Introduction to MSDP Multicast source discovery protocol (MSDP) is an inter-domain multicast solution
developed to address the interconnection of protocol independent multicast
sparse mode (PIM-SM) domains. It is used to discover multicast source information
in other PIM-SM domains.
In the basic PIM-SM mode, a multicast source registers only with the RP in the local
PIM-SM domain, and the multicast source information of a domain is isolated
from that of another domain. As a result, the RP is aware of the source
information only within the local domain and a multicast distribution tree is built
only within the local domain to deliver multicast data from a local multicast source
to local receivers. If there is a mechanism that allows RPs of different PIM-SM
domains to share their multicast source information, the local RP will be able to
join multicast sources in other domains and multicast data can be transmitted
among different domains.
MSDP achieves this objective. By establishing MSDP peer relationships among RPs
of different PIM-SM domains, source active (SA) messages can be forwarded
among domains and the multicast source information can be shared.
c
CAUTION:
■
MSDP is applicable only if the intra-domain multicast protocol is PIM-SM.
■
MSDP is meaningful only for the any-source multicast (ASM) model.
How MSDP Works MSDP peers
With one or more pairs of MSDP peers configured in the network, an MSDP
interconnection map is formed, where the RPs of different PIM-SM domains are