Introduction To Igmp; Igmp Features Supported By The S3700 - Huawei Quidway s3700 series Configuration Manual

Quidway S3700 Series Ethernet Switches
Configuration Guide - Multicast

5.1 Introduction to IGMP

This section describes the principle of IGMP.
In the TCP/IP protocol suite, the Internet Group Management Protocol (IGMP) manages IPv4
multicast members. It sets up and maintains the multicast membership between IP hosts and
adjacent multicast routers.
As a routing switch, the S3700 supports IP multicast. When IGMP is configured, the S3700 can
be used as a multicast switch. IGMP is the signaling mechanism of the host towards the
S3700, which is used by IP multicast in an end user network. IGMP needs to be enabled on hosts
and on S3700s.
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At present, IGMP has three versions: IGMPv1 (defined by RFC 1112), IGMPv2 (defined by
RFC 2236), and IGMPv3 (defined by RFC 3376). All IGMP versions support the Any-Source
Multicast (ASM) model. IGMPv3 can be directly applied to the Source-Specific Multicast
(SSM) model, while IGMPv1 and IGMPv2 require the support of SSM mapping.

5.2 IGMP Features Supported by the S3700

This section describes IGMP features supported by the S3700.
Basic IGMP Functions
The basic IGMP features that the S3700 supports are as follows:
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Router-Alert Option
IGMPv2 and IGMPv3 have the Group-Specific and Source/Group-Specific Query messages.
The groups are varied and an S3700 cannot join all groups. Therefore, the IGMP needs to use
the Router-Alert option. Then the IGMP can send messages for the groups that the local
S3700 does not join to the upper-level protocol for processing.
Issue 01 (2011-10-26)
NOTE
The S3700SI does not support IGMP.
NOTE
l Whether the host supports IGMP depends on the used operating system.
l The switch mentioned in the following contents is an S3700 supporting the Layer 3 multicast protocol
and multicast router function.
All receiver hosts that participate in multicast transmission must be enabled with IGMP.
A host can join or leave a multicast group at any time and from any position. The number
of members of a multicast group is not limited.
Through IGMP, a multicast L3 device can know whether there is a multicast group receiver,
namely, a group member, on the network segment to which an interface of the router is
connected. Each host needs to save only the information about the groups that the host itself
joins.
Supporting IGMPv1, IGMPv2, and IGMPv3 and configurable version.
Supporting the static IGMP.
Configuring the range of multicast groups that an interface can join.
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5 IGMP Configuration
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