Configuring Igmp Snooping; Overview; Basic Igmp Snooping Concepts - HP FlexNetwork NJ5000 User Manual

Configuring IGMP snooping

Overview

IGMP snooping runs on a Layer 2 switch as a multicast constraining mechanism to improve multicast
forwarding efficiency. It creates Layer 2 multicast forwarding entries from IGMP packets that are
exchanged between the hosts and the router.
As shown in
packets to all hosts. When IGMP snooping is enabled, the Layer 2 switch forwards multicast packets
of known multicast groups to only the receivers of the multicast groups.
Figure 204 Multicast forwarding before and after IGMP snooping is enabled

Basic IGMP snooping concepts

This section lists the basic IGMP snooping concepts.
IGMP snooping related ports
As shown in
receivers in a multicast group.
Figure 204, when IGMP snooping is not enabled, the Layer 2 switch floods multicast
Figure 205, IGMP snooping runs on Switch A and Switch B, Host A and Host C are
204