D-Link DI-1750 Reference Manual page 306

7.2.6 Configure IGMP Querier interval
For the IGMP-Router port protocol version 2 and version 3, if exist routers, they run the same
IGMP-Router port protocol in the same network, it need to face the problem of querier select ion, the
definition of querier is the router which could send the query message (in fact, the port on the router
which start the IGMP-Router port protocol), under the normal running, there is only one querier in the
same network, it means only one router could send IGMP Query message. For IGMP-Router port
protocol version 1, there is no problem about querier select ion, because in IGMP-Router version 1,
which router could send IGMP Query message is specified by multicast-group route protocol.
For the IGMP-Router port protocol version 2 and version 3, use the same querier select ion mechanism:
the router which have the least ip address is the querier of the network. For the non-querier, it needs to
save one clock which used to record the time querier existed, when the clock is overtime, non-querier
change to querier, and then start sending IGMP Query message until the router receives the IGMP
Query message which is sent by the router who have the less ip address, and the querier change to
non-querier again.
For IGMP-Router port protocol version 2, other querier existance interval could be configured by the
following command :
Command
ip igmp querier-timeout time
Choose the 17th option in the parameter clew, notify
(00)access-group
......
(06)igmp
......
Please Input the code of command to be excute(0-22): 6
input 6，choose igmp option，notify：
(00)helper-address
......
(04)querier-timeout
......
Please Input the code of command to be excute(0-8): 4
input 4，choose querier-timeout option，then input
Example of configuring IGMP Querier Interval
The following example demonstrate the process that administrator change the IGMP Querier Interval
on one port to 100s.
interface ethernet 0/0
ip igmp querier-timeout 100
7.2.7 Configure IGMP max response time
For the IGMP-Router port protocol version 2 and version 3, when sending IGMP General Query
message, there is special data domain which specify the max response time of IGMP host in the IGMP
message, it means that IGMP host must send the response message for the General Query message
in the max response time after it receive the IGMP General Query message. If the max response time
is set too long, it will lead to the delay of the IGMP host multicast-group member identity change. If the
max response time is set too short, it will lead to the large flow of IGMP message in the network.
Note : IGMP max response time must less than the IGMP Query Interval, when using the configuration
command, if max response time is more than the IGMP Query Interval, system will auto set the max
response time to query-interval-1.
For the IGMP-Router port protocol version 2 and version 3, set IGMP max response time could use the
following command under the port configuration.
Model Name
Purpose
Configure other querier existence interval, unit is
second.
Specify access control for packets
IGMP interface command
relay igmp packet
other querier exist time
time.
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