R21xx-HP FlexFabric 11900 IP Multicast Configuration Guide
Table Of Contents
- Title Page
- Contents
- Multicast overview
- Configuring IGMP snooping
- Overview
- IGMP snooping configuration task list
- Configuring basic IGMP snooping functions
- Configuring IGMP snooping port functions
- Configuring IGMP snooping policies
- Displaying and maintaining IGMP snooping
- IGMP snooping configuration examples
- Troubleshooting IGMP snooping
- Configuring multicast routing and forwarding
- Configuring IGMP
- Configuring PIM
- Overview
- Configuring PIM-DM
- Configuring PIM-SM
- Configuring common PIM features
- Displaying and maintaining PIM
- PIM configuration examples
- Troubleshooting PIM
- Configuring MLD snooping
- Overview
- MLD snooping configuration task list
- Configuring basic MLD snooping functions
- Configuring MLD snooping port functions
- Configuring MLD snooping policies
- Displaying and maintaining MLD snooping
- MLD snooping configuration examples
- Troubleshooting MLD snooping
- Configuring IPv6 multicast routing and forwarding
- Configuring MLD
- Configuring IPv6 PIM
- PIM overview
- Configuring IPv6 PIM-DM
- Configuring IPv6 PIM-SM
- Configuring common IPv6 PIM features
- Displaying and maintaining IPv6 PIM
- IPv6 PIM configuration examples
- Troubleshooting IPv6 PIM
- Support and other resources
- Index

13
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 10,
when IGMP snooping is not enabled, the Layer 2 switch floods multicast packets
to all devices. When IGMP snooping is enabled, the Layer 2 switch forwards multicast packets of known
multicast groups to only the receivers.
Figure 10 Multicast packet transmission without and with IGMP snooping
Basic IGMP snooping concepts
IGMP snooping related port
As shown in Figure 11, IGMP snooping runs on Switch A and Switch B, and Host A and Host C are
receivers in a multicast group.










