3Com 3031 Command Reference Manual page 706

706 C 7: M C C C
HAPTER ULTICAST OMMON ONFIGURATION OMMANDS
Description
Using the igmp timer other-querier-present command, you can configure the
overtime value of presence of IGMP querier. Using the undo igmp timer
other-querier-present command, you can restore the default value.
On a shared network, i.e., there are multiple multicast routers on the same
network segment, the query router (querier for short) takes charge of sending
query messages periodically on the interface. If other non-queriers receive no
query messages within the valid period, the router will consider the previous query
to be invalid and the router itself becomes a querier.
In IGMP Version 1, the selection of a querier is determined by the multicast routing
protocol. In IGMP Version 2, the router with the lowest IP address on the shared
network segment acts as the querier.
For the related commands, see igmp timer query and display igmp interface.
CAUTION: If the querier present time configured is less than the twice of query
interval, it may lead to the repeated changes of queriers in the network.
Example
Configure the querier present time on the interface Ethernet1/0/0 to 200 seconds.
<3Com-Ethernet1/0/0] igmp timer other-querier-present 200
igmp timer query Syntax
igmp timer query seconds
undo igmp timer query
View
Interface view
Parameter
seconds: Interval at which the router sends the IGMP query messages, in second. It
ranges from 1 to 18000. By default, the value is 60 seconds.
Description
Using the igmp timer query command, you can configure the interval at which a
router interface sends IGMP query messages. Using the undo igmp timer query
command, you can restore the default value.
A multicast router sends IGMP query messages at intervals to find out whether
there are multicast group members on the network. The query interval can be
modified according to the practical conditions of the network.
For the related command, see igmp timer other-querier-present.
Example
Configure the interval at which multicast router Ethernet1/0/0 sends IGMP query
packet to 125 seconds.
<3Com-Ethernet1/0/0] igmp timer query 125