Command Reference Guide

3Com Router 3000 Ethernet Family
Command Reference Guide Chapter 2 IGMP Configuration Commands
3Com Corporation
2-11
View
Interface view
Parameter
seconds: IGMP querier present time, in second. The value ranges from 1 to 131070
seconds. By default, the value is twice of IGMP query messages interval. It is 120
seconds in general.
Description
Use the igmp timer other-querier-present command to configure the overtime value
of presence of IGMP querier.
Use the undo igmp timer other-querier-present command to 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.
Related command: igmp timer query, 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
2.1.14 igmp timer query
Syntax
igmp timer query seconds
undo igmp timer query