252
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 Figure 227, w
hen IGMP snooping is not enabled, the Layer 2 switch floods multicast 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 227 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 Figure 228, IGMP snooping runs on Switch A and Switch B, Host A and Host C are receivers
in a multicast group.
To Next Page
Loading...
Need help?
General
