Chapter 2 Igmp Snooping Configuration; Igmp Snooping Fundamentals - Huawei Quidway S5600 Series Operation Manual

Operation Manual – Multicast Protocol
Quidway S5600 Series Ethernet Switches-Release 1510

Chapter 2 IGMP Snooping Configuration

2.1 Overview

2.1.1 IGMP Snooping Fundamentals

Internet group management protocol snooping (IGMP Snooping) is a multicast control
mechanism running on Layer 2 switch. It is used to manage and control multicast
groups.
When the IGMP messages transferred from the hosts to the router pass through the
Layer 2 switch, the switch uses IGMP Snooping to analyze and process the IGMP
messages, as shown in Table 2-1.
Table 2-1 IGMP message processing on the switch
Received
message type
IGMP host report
message
IGMP
message
By listening to IGMP messages, the switch establishes and maintains MAC multicast
address tables at data link layer, and uses the tables to forward the multicast packets
delivered from the router.
As shown in Figure 2-1, multicast packets are broadcasted at Layer 2 when IGMP
Snooping is disabled and multicasted (not broadcasted) at Layer 2 when IGMP
Snooping is enabled.
Sender
Host
leave
Host
Huawei Technologies Proprietary
2-1
Chapter 2 IGMP Snooping Configuration
Receiver Switch processing
Add
Switch
corresponding multicast group.
Remove the host from the
Switch
multicast group.
the host to the