Allied Telesis AlliedWare Plus Operating System Version 5.4.4C (x310-26FT,x310-26FP,x310-50FT,x310-50FP) - Manual (Page 728)

IGMP and IGMP Snooping Introduction
Software Reference for x310 Series Switches
30.2 AlliedWare Plus TM Operating System - Version 5.4.4C C613-50046-01 REV A
Introduction
This chapter provides information about Internet Group Management Protocol (IGMP),
IGMP Snooping, and an introduction to the Query Solicitation feature when used with
IGMP Snooping. To see details on the commands used in this example, or to see the
outputs of the validation commands, refer to
Chapter 31, IGMP Snooping Commands .
IGMP
Internet Group Management Protocol (IGMP) is the protocol that hosts use to indicate that
they are interested in receiving a particular multicast stream. An example of a multicast
system within a single Layer 2 LAN is shown in
Figure 30-1 .
Figure 30-1: Multicast system within a single LAN
1 2 3 4
Path of multicast tree
1 4 to Multicast hosts/clients
Multicast
source
LAN
IGMP Querier
(also known as
a multicast router)
Layer 2 switches
perform IGMP
snooping
Querier sends IGMP queries
to discover which hosts are
still joined
multicast_2
Multicast hosts send IGMP requests to join and leave groups