3Com 10014298 manual Configuring the Igmp Querier Present Timer

122CHAPTER 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.

Table 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	undo igmp timer
default value	other-querier-present

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.

Table 130 Configure the Maximum Query Response Time

Operation	Command
Configure the maximum query response time	igmp max-response-time seconds
for IGMP
Restore the maximum query response time to	undo igmp max-response-time
the default value

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.

Table 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 ] } }