332 CHAPTER 18: MULTICAST PROTOCOL
Configuring the Present Time of IGMP Querier
The IGMP querier present timer defines the period of time before the router takes
over as the querier sending query messages, after the previous querier has stopped
doing so.
Perform the following configuration in 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 Maximum Response Time for IGMP Query Message
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 reasonably can enable the host to respond to
query messages quickly. In this case, the router can fast master the existing status of
the members of the multicast group.
Perform the following configuration in 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. By default, the maximum query response time is 10 seconds.
Deleting IGMP Groups Joined on an Interface
You can delete an existing IGMP group from the interface using the following
command.
Perform the following configuration in Interface view.
Table 337 Configuring the present time of IGMP querier
Operation Command
Change the present time of IGMP
querier
igmp timer other-querier-present seconds
Restore the default value undo igmp timer other-querier-present
Table 338 Configuring the maximum response time for IGMP query message
Operation Command
Configure the maximum response time for IGMP
query message
igmp max-response-time seconds
Restore the maximum query response time to the
default value
undo igmp max-response-time
Table 339 Deleting 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 ] } }
