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Catalyst 3750 SwitchSoftware Configuration Guide
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Configuring IP Multicast Routing
This chapter describes how to configure IP multicast routing on the Catalyst 3750 switch. IP multicasting
is a more efficient way to use network resources, especially for bandwidth-intensive services such as
audio and video. IP multicast routing enables a host (source) to send packets to a group of hosts
(receivers) anywhere within the IP network by using a special form of IP address called the IP multicast
group address. The sending host inserts the multicast group address into the IP destination address field
of the packet, and IP multicast routers and multilayer switches forward incoming IP multicast packets
out all interfaces that lead to members of the multicast group. Any host, regardless of whether it is a
member of a group, can send to a group. However, only the members of a group receive the message.
To use the IP multicast routing features, the stack master must be running the IP serv ices image. To use
the PIM stub routing feature, the stack master can be running the IP base image.
Unless otherwise noted, the term switch refers to a standalone switch and to a 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 from the Cisco.com page under
Documentation > Cisco IOS Software > 12.2 Mainline > Command References.
This chapter consists of these sections:
Understanding Cisco’s Implementation of IP Multicast Routing, page46-2
Multicast Routing and Switch Stacks, page46-10
Configuring IP Multicast Routing, page46-10
Configuring Advanced PIM Features, page46-35
Configuring Optional IGMP Features, page46-38
Configuring Optional Multicast Routing Features, page46-44
Configuring Basic DVMRP Interoperability Features, page46-48
Configuring Advanced DVMRP Interoperability Features, page46-53
Monitoring and Maintaining IP Multicast Routing, page46-61
For information on configuring the Multicast Source Discovery Protocol (MSDP), see Chapter47,
“Configuring MSDP.”