igmp-snooping query-interval
Function
The igmp-snooping query-interval command sets the general query interval in a VLAN, that is, the interval at which IGMP General Query messages are sent in the VLAN.
The undo igmp-snooping query-interval command restores the default general query interval in a VLAN.
By default, the general query interval is 60 seconds.
Usage Guidelines
Usage Scenario
By setting the general query interval, you can:
Configure the wireless access controller to send IGMP General Query messages at intervals to maintain memberships of interfaces. When a shorter interval is configured, the wireless access controller is more sensitive to multicast membership changes, but more bandwidth and system resources are consumed.
Change the aging time of multicast member ports.
When receiving an IGMP Report message from a host, the wireless access controller starts the aging timer for the multicast member port. The aging time is calculated using the following formula: Aging time = General query count x General query interval + Maximum response time for General Query messages. The igmp-snooping query-interval command sets the general query interval. The general query count is set by the igmp-snooping robust-count command, and the maximum response time for General Query messages is set by the igmp-snooping max-response-time command.
The default interval value in this command is 60 seconds, which is different than the default value 125 seconds defined by the RFC standard. A Huawei querier and a non-Huawei querier must send IGMP general query messages at the same interval.
Prerequisites
IGMP snooping has been enabled globally using the igmp-snooping enable (system view) command.
Precautions
The configuration takes effect only after you run the igmp-snooping enable (VLAN view) command to enable IGMP snooping in the VLAN.
Use this command only when the wireless access controller can send IGMP Query messages. The wireless access controller can send IGMP Query messages only when IGMP snooping proxy is enabled using the igmp-snooping proxy command, or IGMP snooping querier is enabled using the igmp-snooping querier enable command.
The interval at which General Query messages are sent must be longer than the maximum response time for General Query messages. Otherwise, the wireless access controller may delete multicast memberships that should not be deleted.
