Configuring igmp snooping, Overview, Basic igmp snooping concepts – H3C Technologies H3C S12500-X Series Switches User Manual
Page 24: Igmp snooping related ports, Multicast support for vpns, Introduction to vpn instances

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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
, when 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.
Figure 11 Multicast packet transmission without and with IGMP snooping
Basic IGMP snooping concepts
IGMP snooping related ports
As shown in
, IGMP snooping runs on Switch A and Switch B, and Host A and Host C are
receivers in a multicast group.
- H3C S9800 Series Switches H3C S5560 Series Switches H3C S5130 Series Switches H3C S5120 Series Switches H3C S12500 Series Switches H3C SR8800 H3C SR6600-X H3C SR6600 H3C WX6000 Series Access Controllers H3C WX5000 Series Access Controllers H3C WX3000 Series Unified Switches H3C LSWM1WCM10 Access Controller Module H3C LSWM1WCM20 Access Controller Module H3C LSQM1WCMB0 Access Controller Module H3C LSRM1WCM2A1 Access Controller Module H3C LSBM1WCM2A0 Access Controller Module