122 CHAPTER 6: MULTICAST PROTOCOL
Configuring the IGMP Querier Present Timer
The IGMP querier present timer defines the period of time before the router takes
over as the querier.
Perform the following configuration in VLAN interface view.
By default, the value is 120 seconds. If the router has received no query message
within twice the interval specified by the igmp timer query command, it will
regard the previous querier invalid.
Configuring the Maximum Query Response Time
When a router receives a query message, the host will set a timer for each
multicast group it belongs to. The value of the timer is randomly selected between
0 and the maximum response time. When any timer becomes 0, the host will send
the membership report message of the multicast group.
Setting the maximum response time allows the host to respond to query messages
quickly. In this case, the router can master the existing status of the members of
the multicast group.
Perform the following configuration in VLAN interface view.
The smaller the maximum query response time value, the faster the router prunes
groups. The actual response time is a random value in the range from 1 to 25
seconds. The default value is 10 seconds.
Deleting IGMP Groups Joined on an Interface
You can delete an existing IGMP group from the interface via the following
command.
Perform the following configuration in VLAN interface view.
Tabl e 129 Configure the IGMP Querier Present Timer
Operation Command
Change the IGMP querier present timer igmp timer other-querier-present
seconds
Restore the IGMP querier present timer to the
default value
undo igmp timer
other-querier-present
Tabl e 130 Configure the Maximum Query Response Time
Operation Command
Configure the maximum query response time
for IGMP
igmp max-response-time seconds
Restore the maximum query response time to
the default value
undo igmp max-response-time
Tabl e 131 Delete IGMP Groups Joined on an Interface
Operation Command
Delete IGMP groups joined on an interface reset igmp group { all |
interface interface-type
interface-number { all |
group-address [ group-mask ] } }