Configuring Igmp; Igmp Overview; Igmp Versions; Introduction To Igmpv1 - HP A6600 Configuration Manual

Configuring IGMP

The interfaces in this document refer to Layer 3 interfaces in generic sense and Ethernet interfaces
operating in route mode. For more information about the operating mode of the Ethernet interface, see
Layer 2—LAN Switching Configuration Guide.

IGMP overview

As a TCP/IP protocol responsible for IP multicast group member management, the Internet Group
Management Protocol (IGMP) is used by IP hosts and adjacent multicast routers to establish and maintain
their multicast group memberships.

IGMP versions

IGMPv1 (documented in RFC 1112)
•
IGMPv2 (documented in RFC 2236)
•
IGMPv3 (documented in RFC 3376)
•
All IGMP versions support the ASM model. In addition to the ASM model, IGMPv3 can directly implement
the SSM model. IGMPv1 and IGMPv2 must work with the IGMP SSM mapping function to implement the
SSM model.
For more information about the ASM and SSM models, see

Introduction to IGMPv1

IGMPv1 manages multicast group memberships mainly based on the query and response mechanism.
All the multicast routers on the same subnet can get IGMP membership report messages—often called
"reports"— from hosts, but the subnet needs only one router for sending IGMP query messages—often
called "queries". The querier election mechanism determines which router acts as the IGMP querier on
the subnet.
In IGMPv1, the designated router (DR) elected by the working multicast routing protocol (such as PIM)
serves as the IGMP querier.
For more information about DR, see "Configuring PIM."
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"Configuring IP multicast."