The igmp-snooping lastmember-queryinterval command sets the last member query interval in a VSI, that is, the interval at which Group-Specific Query messages are sent in the VSI.
The undo igmp-snooping lastmember-queryinterval command restores the default last member query interval in a VSI.
By default, Group-Specific Query messages are sent in a VSI at intervals of 1 second.
igmp-snooping lastmember-queryinterval lastmember-queryinterval
undo igmp-snooping lastmember-queryinterval
Parameter |
Description |
Value |
|---|---|---|
lastmember-queryinterval |
Specifies the interval at which IGMP Group-Specific Query messages are sent. |
The value is an integer that ranges from 1 to 5, in seconds. |
Usage Scenario
When a member interface receives an IGMP Leave message from a downstream host, the switch starts the aging timer for the interface. The aging time is calculated using the following formula: Aging time = Last member query interval x Last member query count. The igmp-snooping lastmember-queryinterval command sets the last member query interval. The last member query count is set by the igmp-snooping robust-count command.
If the member interface receives Report messages from downstream hosts within the aging time, the switch retains the member interface in the outbound interface list of the corresponding Layer 2 multicast forwarding entry. If the member interface does not receive any Report messages within the aging time, the switch considers that no group member is connected to the interface, and therefore deletes the interface from the Layer 2 multicast forwarding entry.
Prerequisites
IGMP snooping has been enabled for VPLS using the igmp-snooping over-vpls enable command in the system view.
Precautions
The configuration takes effect only when IGMP snooping is enabled in the VSI using the igmp-snooping enable (VSI view) command.
Hosts running IGMPv1 do not send Leave messages when they leave a multicast group. Therefore, the igmp-snooping lastmember-queryinterval command is valid only when the IGMP message version is set to v2 or v3 in the VSI.