Chapter 3 Igmp Snooping Configuration; Igmp Snooping Overview - Huawei Quidway S3500 Series Operation Manual

Operation Manual - Multicast
Quidway S3500 Series Ethernet Switches

Chapter 3 IGMP Snooping Configuration

Note:
Among S3500 Series Ethernet Switches, S3552G/S3552P/S3552F/S3528G/S3528P
support IGMP Snooping.

3.1 IGMP Snooping Overview

3.1.1 IGMP Snooping Principle
IGMP Snooping (Internet Group Management Protocol Snooping) is a multicast control
mechanism running on the Layer 2 Ethernet switch and it is used for multicast group
management and control.
IGMP Snooping runs on the link layer. When receiving the IGMP messages transmitted
between the host and router, the Layer 2 Ethernet switch uses IGMP Snooping to
analyze the information carried in the IGMP messages. If the switch hears IGMP host
report message from an IGMP host, it will add the host to the corresponding multicast
table. If the switch hears IGMP leave message from an IGMP host, it will remove the
host from the corresponding multicast table. The switch continuously listens to the
IGMP messages to create and maintain MAC multicast address table on Layer 2. And
then it can forward the multicast packets transmitted from the upstream router
according to the MAC multicast address table.
When IGMP Snooping is disabled, the packets are multicast on Layer 2. See the
following figure:
Huawei Technologies Proprietary
3-1
Chapter 3 IGMP Snooping Configuration