Igmp configuration, Overview, Igmp versions – H3C Technologies H3C SecPath F1000-E User Manual
Page 357: Introduction to igmpv1
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IGMP Configuration
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When configuring IGMP, go to the following sections for the information you are interested in:
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NOTE:
The term "router" in this document refers to a network device running an IP routing protocol.
Overview
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.
IGMP Versions
So far, there are three IGMP versions:
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IGMPv1 (documented in RFC 1112)
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IGMPv2 (documented in RFC 2236)
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IGMPv3 (documented in RFC 3376)
All IGMP versions support the Any-Source Multicast (ASM) model. In addition to support of the ASM
model, IGMPv3 can be directly deployed to implement the Source-Specific Multicast (SSM) model, while
IGMPv1 and IGMPv2 need to work with the IGMP SSM mapping function to implement the SSM model.
NOTE:
Currently, the Web interface does not support configuration of IGMP SSM mapping.
Introduction to IGMPv1
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). In this case, 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 the working multicast routing protocol (such as PIM)
serves as the IGMP querier.
NOTE:
For more information about DR, see
PIM Configuration in the Firewall Web Configuration Manual.