Cisco Gigabit Ethernet Switch Module for HP p-Class BladeSystem Software Configuration Guide

CHAPTER

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Configuring IGMP Snooping and MVR

This chapter describes how to configure Internet Group Management Protocol (IGMP) snooping on the

switch, including an application of local IGMP snooping, Multicast VLAN Registration (MVR). It also

includes procedures for controlling multicast group membership by using IGMP filtering and procedures

for configuring the IGMP throttling action.

Note For complete syntax and usage information for the commands used in this chapter, see the switch

command reference for this release and the “IP Multicast Routing Commands” section in the Cisco IOS

IP Command Reference, Volume 3 of 3:Multicast, Release 12.2.

This chapter consists of these sections:

• Understanding IGMP Snooping, page 17-1

• Configuring IGMP Snooping, page 17-6

• Displaying IGMP Snooping Information, page 17-15

• Understanding Multicast VLAN Registration, page 17-17

• Configuring MVR, page 17-19

• Displaying MVR Information, page 17-23

• Configuring IGMP Filtering and Throttling, page 17-23

• Displaying IGMP Filtering and Throttling Configuration, page 17-28

Note You can either manage IP multicast group addresses through features such as IGMP snooping and MVR,

or you can use static IP addresses.

Understanding IGMP Snooping

Layer 2 switches can use IGMP snooping to constrain the flooding of multicast traffic by dynamically

configuring Layer 2 interfaces so that multicast traffic is forwarded to only those interfaces associated

with IP multicast devices. As the name implies, IGMP snooping requires the LAN switch to snoop on

the IGMP transmissions between the host and the router and to keep track of multicast groups and

member ports. When the switch receives an IGMP report from a host for a particular multicast group,

the switch adds the host port number to the forwarding table entry; when it receives an IGMP Leave

Group message from a host, it removes the host port from the table entry. It also periodically deletes

entries if it does not receive IGMP membership reports from the multicast clients.