Allied Telesis AR400 manual Default Query Interval, What this timer does, How to change this timer

Configurable IGMP timers and counters > Default Query Interval

Default Query Interval

What this timer does

To maintain an accurate picture of group membership, the Querier periodically sends General Queries to all its IGMP interfaces. The Default Query Interval is the gap between General Queries.

Note that General Queries are quite different from Specific Queries, which the Querier sends to a group address when it receives a Leave message for that group.

The router or switch only sends General or Specific Queries if it is the Querier. If another router or switch is elected as the Querier, the non-elected router or switch ignores the Default Query Interval and other such settings.

Potential problems with changing this timer

If you change the Default Query Interval, the Default Timeout Interval also needs to change so that clients have an appropriate amount of time to reply to the Query. Since software versions 281-03 and 2.9.1, this happens automatically. For earlier versions, you need to change it yourself as described on page 82.

How to change this timer

The Default Query Interval is an integer from 1 to 65535 seconds, specified using the queryinterval parameter. The default is 125 seconds. The following example tweaks the interval. Note that the Default Timeout Interval also changes.

Manager Switch 1> set ip igmp queryinterval=120

Info (1005003): Operation successful.

Manager Switch 1> show ip igmp

IGMP Protocol

------------------------------------------------------------------------

Status	Enabled
Default Query Interval	120	secs
Default Timeout Interval	250	secs
Last Member Query Interval	10 (1/10secs)
Last Member Query Count	2
Robustness Variable	2
Query Response Interval	100	(1/10secs)
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Page 76 AlliedWare™ OS How To Note: IGMP