3Com Switch 7750 Series
Command Reference Guide – Multicast Chapter 4 IGMP Configuration Commands
4-9
System View: return to User View with Ctrl+Z.
[3Com] interface Vlan-interface 10
[3Com-Vlan-interface10] igmp enable
[3Com-Vlan-interface10] quit
[3Com] interface Ethernet 0/1
[3Com-Ethernet0/1] port access vlan 10
[3Com-Ethernet0/1] igmp host-join 225.0.0.1 vlan 10
4.1.9 igmp lastmember-queryinterval Syntax
igmp lastmember-queryinterval seconds
undo igmp lastmember-queryinterval
View
VLAN interface view
Parameter
seconds: Interval for the IGMP querier to send IGMP group-specific query packets
when it receives IGMP leave packets from the host. It is in the range of 1 second to 5
seconds.
Description
Use the igmp lastmember-queryinterval command to set the Interval for the IGMP
querier to send IGMP group-specific query packets when it receives IGMP leave
packets from the host.
Use the undo igmp lastmember-queryinterval command to restore the default value.
The interval for the IGMP querier to send IGMP group-specific query packets is one
second by default.
In the shared network, that is, a same network segment including multiple hosts and
multicast routers, the query router (also known as querier) is responsible for
maintaining the IGMP group membership on the interface. When the IGMP v2 host
leaves a group, it sends an IGMP Leave message.
When receiving the IGMP Leave message, the IGMP querier must send the IGMP
group-specific query messages for specified times (by the robust-value argument in the
igmp robust-count command, with default value as 2) in a specified time interval (by
the seconds argument in the igmp lastmember-queryinterval command, with default
value as 1 second). If other hosts which are interested in the specified group receive
the IGMP query message from the IGMP query router, they will send back the IGMP
Membership Report message within the specified maximum response time interval. If it
receives the IGMP Membership Report message within the defined period (equal to