3Com 3031 Command Reference Manual page 703

IGMP Configuration Commands 703
Description
Using the igmp lastmember-queryinterval command, you can set the interval at
which IGMP querier sends the IGMP specified group query packet when it receives
IGMP Leave packet from the host. Using the undo igmp lastmember-queryinterval
command, you can restore the default value.
On a shared network, that is, when there are multiple hosts and multicast routers
on a network segment, the query router (querier for short) takes charge of
maintaining IGMP group membership on an interface. When the host in IGMP
Version 2 leaves a group, the host should send IGMP Leave packet. If IGMP querier
receives the packet, it must send the IGMP specified group query packet for
robust-value times according to the interval seconds configured via igmp
lastmember-queryinterval command (if the command is not configured, seconds is
1) and the robust coefficient robust-value configured via igmp robust-count (if the
command is not configured, robust-value is 2). If another host receives the IGMP
specified group query packet from IGMP querier and is interested in the group, it
will send IGMP Membership Report packet within the maximum response time
regulated by the packet. If IGMP querier receives IGMP Membership Report packet
from another host within the time robust-value x seconds, it will go on
maintaining the group membership. If not, it will regard the group is timeout and
stop maintaining the group membership.
The command is only valid when IGMP query router is running in IGMP Version 2.
If the host runs in IGMP Version 1, it may not send IGMP Leave packet when it
leaves a group. At that time, the command is invalid to the host.
For the related commands, see igmp robust-count and display igmp interface.
Example
Configure the query interval of the querier for the last group member on the
interface Ethernet1/0/0 to 3 seconds.
<3Com-Ethernet1/0/0] igmp lastmember-queryinterval 3
igmp max-response-time Syntax
igmp max-response-time seconds
undo igmp max-response-time
View
Interface view
Parameter
seconds: The maximum response time in the IGMP query packet in second,
ranging from 1 to 25. By default, the value is 10 seconds.
Description
Using the igmp max-response-time command, you can configure the maximum
response time contained in the IGMP query packet. Using the undo igmp
max-response-time command, you can restore the default value.