Configuring Igmp Queries And Responses - H3C S3610-28P Operation Manual

Operation Manual – Multicast Protocol
H3C S3610&S5510 Series Ethernet Switches
IGMP last-member query interval,
Maximum response time to IGMP general queries,
Source address of IGMP general queries, and
Source address of IGMP group-specific queries.
2.5.2 Enabling IGMP Snooping Querier
In an IP multicast network running IGMP, a multicast router or Layer 3 multicast switch
is responsible for sending IGMP general queries, so that all Layer 3 multicast devices
can establish and maintain multicast forwarding entries, thus to forward multicast traffic
correctly at the network layer. This router or Layer 3 switch is called IGMP querier.
However, a Layer 2 multicast switch does not support IGMP, and therefore cannot send
general queries by default. By enabling IGMP Snooping on a Layer 2 switch in a VLAN
where multicast traffic needs to be Layer-2 switched only and no multicast routers are
present, the Layer 2 switch will act as the IGMP Snooping querier to send IGMP
queries, thus allowing multicast forwarding entries to be established and maintained at
the data link layer.
Follow these steps to enable IGMP Snooping querier:
Enter system view
Enter VLAN view
Enable IGMP Snooping
querier
Caution:
It is meaningless to configure an IGMP Snooping querier in a multicast network running
IGMP. Although an IGMP Snooping querier does not take part in IGMP querier
elections, it may affect IGMP querier elections because it sends IGMP general queries
with a low source IP address.

2.5.3 Configuring IGMP Queries and Responses

You can tune the IGMP general query interval based on actual condition of the network.
Upon receiving an IGMP query (general query or group-specific query), a host starts a
timer for each multicast group it has joined. This timer is initialized to a random value in
the range of 0 to the maximum response time (the host obtains the value of the
maximum response time from the Max Response Time field in the IGMP query it
To do...
system-view
vlan vlan-id
igmp-snooping querier
Chapter 2 IGMP Snooping Configuration
Use the command...
2-14
Remarks
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Required
Disabled by default