Command

Enable the IGMP querier

Multicast switches can send IGMP host-query messages to discover which multicast groups are present on attached networks. These messages are sent to the all-systems group address of 224.0.0.1 with a time-to-live (TTL) value of 1.

Multicast switches continue to periodically send host-query messages to refresh their knowledge of memberships present on their networks. If, after some number of queries, the switch software discovers that no local hosts are members of a multicast group, the software stops forwarding onto the local network multicast packets from remote origins for that group and sends a prune message upstream toward the source.

The switch can be configured to send IGMP queries which are used to solicit IGMP hosts report messages. The switch uses the report messages to keep track of which ports belong to which IP multicast group.

To enable/disable IGMP querier , use the command below:

Command

Purpose

 

 

set igmp-querier {enable disable}

Enable/Disable IGMP querier

 

 

Modifying the IGMP Host-Query Message Interval

Multicast switches elect a designated switch for the LAN (subnet). The designated switch is the one with the highest IP address. The switch is responsible for sending IGMP host-query messages to all hosts on the LAN. By default, the designated switch sends IGMP host-query messages every 60 seconds in order to keep the IGMP overhead on hosts and networks very low. To modify this interval, use the following command in interface configuration mode:

Command

Purpose

 

 

set igmp query-interval <10-3600 seconds>

Configure the frequency at which the designated switch sends

 

IGMP host-query messages.

 

 

The following example shows setting the IGMP query interval to 200.

Switch(config)# set igmp query-interval 200

Changing the Maximum Query Response Time

By default, the maximum query response time advertised in IGMP queries is 10 seconds. If the switch is using IGMP Version 2, you can change this value. To change the maximum query response time, use the following command in configuration mode:

Command

 

Purpose

 

 

 

set igmp query-resinterval <0-200 seconds>

Set the maximum query response time advertised

 

 

in IGMP queries.

 

 

 

 

 

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Asante IntraCore IC3624/48

User’s Manual

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Asante Technologies 3624/48 user manual Command, Purpose, set igmp query-interval 10-3600 seconds, IGMP host-query messages