CHAPT ER
49-1
Catalyst 3750-X and 3560-X Switch Software Configuration Guide
OL-21521-01
49
Configuring MSDP
This chapter describes how to configure the Multicast Source Discovery Protocol (MSDP) on the
Catalyst 3750-X or 3560-X switch. The MSDP connects multiple Protocol-Independent Multicast
sparse-mode (PIM-SM) domains.
MSDP is not fully supported in this software release because of a lack of support for Multicast Border
Gateway Protocol (MBGP), which works closely with MSDP. However, it is possible to create default
peers that MSDP can operate with if MBGP is not running.
To use this feature, the switch or stack master must be running the IP services feature set. Unless
otherwise noted, the term switch refers to a Catalyst 3750-X or 3560-X standalone switch and to a
Catalyst 3750-X switch stack.
Note For complete syntax and usage information for the commands used in this chapter, see the Cisco IOS IP
Command Reference, Volume 3 of 3: Multicast, Release 12.2.
This chapter consists of these sections:
Understanding MSDP, page 49-1
Configuring MSDP, page 49-3
Monitoring and Maintaining MSDP, page 49-19

Understanding MSDP

MSDP allows multicast sources for a group to be known to all rendezvous points (RPs) in different
domains. Each PIM-SM domain uses its own RPs and does not depend on RPs in other domains. An RP
runs MSDP over the Transmission Control Protocol (TCP) to discover multicast sources in other
domains.
An RP in a PIM-SM domain has an MSDP peering relationship with MSDP-enabled devices in another
domain. The peering relationship occurs over a TCP connection, primarily exchanging a list of sources
sending to multicast groups. The TCP connections between RPs are achieved by the underlying routing
system. The receiving RP uses the source lists to establish a source path.