Igmp Snooping Configuration; Igmp Snooping Overview; Principle Of Igmp Snooping - 3Com 5500-EI PWR Install Manual

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IGMP Snooping Configuration

When configuring IGMP snooping, go to these sections for information you are interested in:

IGMP Snooping Overview

Configuring IGMP Snooping
Displaying and Maintaining IGMP Snooping
IGMP Snooping Configuration Examples
Troubleshooting IGMP Snooping
In this manual, the term "router" refers to a router in the generic sense or a Layer 3 Ethernet switch
running an IP multicast protocol.
IGMP Snooping Overview
Internet Group Management Protocol Snooping (IGMP Snooping) is a multicast constraining
mechanism that runs on Layer 2 devices to manage and control multicast groups.

Principle of IGMP Snooping

By analyzing received IGMP messages, a Layer 2 device running IGMP Snooping establishes
mappings between ports and multicast MAC addresses and forwards multicast data based on these
mappings.
As shown in Figure
broadcast to all devices at Layer 2. When IGMP Snooping is running on the switch, multicast packets for
known multicast groups are multicast to the receivers, rather than broadcast to all hosts, at Layer 2.
However, multicast packets for unknown multicast groups are still broadcast at Layer 2.
6-1, when IGMP Snooping is not running on the switch, multicast packets are
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