Cisco 2950 Software Configuration Guide - Page 425
Configuring IGMP Snooping and MVR, Understanding IGMP Snooping
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21 C H A P T E R Configuring IGMP Snooping and MVR This chapter describes how to configure Internet Group Management Protocol (IGMP) snooping on your Catalyst 2950 or Catalyst 2955 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, refer to the switch command reference for this release and the Cisco IOS Release Network Protocols Command Reference, Part 1, for Cisco IOS Release 12.1. This chapter consists of these sections: • Understanding IGMP Snooping, page 21-1 • Configuring IGMP Snooping, page 21-6 • Displaying IGMP Snooping Information, page 21-13 • Understanding Multicast VLAN Registration, page 21-14 • Configuring MVR, page 21-17 • Displaying MVR Information, page 21-21 • Configuring IGMP Filtering and Throttling, page 21-21 • Displaying IGMP Filtering and Throttling Configuration, page 21-27 Note For MAC addresses that map to IP multicast groups, you can either manage them through features such as IGMP snooping and MVR, or you can use static MAC addresses. However, you cannot use both methods simultaneously. Therefore, before using IGMP snooping or MVR, you should remove all statically configured MAC addresses that map to IP multicast groups. 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, 78-11380-10 Catalyst 2950 and Catalyst 2955 Switch Software Configuration Guide 21-1
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