3Com Switch 7700 Configuration Manual page 211

Perform the following configuration in VLAN-interface view.
Table 14 Limit the Access to IP Multicast Groups
Operation
Limit the range of allowed multicast groups
on current interface
Remove the filter set on the interface
By default, no filters are configured. All multicast groups are allowed on the
interface.
Configuring the IGMP Query Message Interval
Multicast routers send IGMP query messages to find present multicast groups on
other networks. Multicast routers send query messages periodically to refresh their
information of members present.
Perform the following configuration in VLAN interface view.
Table 15 Configure the IGMP Query Message Interval
Operation
Configure the IGMP query message interval
Restore the IGMP query message interval to
the default value
When there are multiple multicast routers on a network segment, the querier is
responsible for sending IGMP query messages to all hosts on the LAN.
The default interval is 60 seconds.
Configuring the IGMP Querier Present Timer
The IGMP querier present timer defines the period of time before the router takes
over as the querier.
Perform the following configuration in VLAN interface view.
Table 16 Configure the IGMP Querier Present Timer
Operation
Change the IGMP querier present timer
Restore the IGMP querier present timer to the
default value
By default, the value is 120 seconds. If the router has received no query message
within twice the interval specified by the igmp timer query command, it will
regard the previous querier invalid.
Configuring the Maximum Query Response Time
When a router receives a query message, the host will set a timer for each
multicast group it belongs to. The value of the timer is randomly selected between
0 and the maximum response time. When any timer becomes 0, the host will send
the membership report message of the multicast group.
Configuring IGMP
Command
igmp group-policy acl-number [ 1 | 2 ]
undo igmp group-policy
Command
igmp timer query seconds
undo igmp timer query
Command
igmp timer other-querier-present seconds
undo igmp timer other-querier-present
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