Igmp Overview; Igmp Versions; Work Mechanism Of Igmpv1 - 3Com MSR 50 Series Configuration Manual

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IGMP Overview

IGMP Versions

Work Mechanism of
IGMPv1
IGMP C
When configuring IGMP, go to the following sections for the information you are
interested in:
"IGMP Overview" on page 1115
■
"IGMP Configuration Task List" on page 1119
■
"Configuring Basic Functions of IGMP" on page 1120
■
"Adjusting IGMP Performance" on page 1123
■
"Displaying and Maintaining IGMP" on page 1127
■
"IGMP Configuration Example" on page 1127
■
"Troubleshooting IGMP" on page 1129
■
As a TCP/IP protocol responsible for IP multicast group member management, the
Internet Group Management Protocol (IGMP) is used by IP hosts to establish and
maintain their multicast group memberships to immediately neighboring multicast
routers.
So far, there are three IGMP versions:
IGMPv1 (documented in RFC 1112)
■
IGMPv2 (documented in RFC 2236)
■
IGMPv3 (documented in RFC 3376)
■
All IGMP versions support the Any-Source Multicast (ASM) model. In addition,
IGMPv3 can be directly used to implement the Source-Specific Multicast (SSM)
model.
n
For more information about the ASM and SSM models, see
page 1088.
IGMPv1 manages multicast group memberships mainly based on the query and
response mechanism.
Of multiple multicast routers on the same subnet, all the routers can hear IGMP
membership report messages (often referred to as reports) from hosts, but only
one router is needed for sending IGMP query messages (often referred to as
queries). So, a querier election mechanism is required to determine which router
will act as the IGMP querier on the subnet.
In IGMPv1, the designated router (DR) elected by a multicast routing protocol
(such as PIM) serves as the IGMP querier.
ONFIGURATION
"Multicast Models" on