mld-snooping lastmember-queryinterval

Function

The mld-snooping lastmember-queryinterval command sets an interval at which a querier sends group-specific or source-and group-specific Query messages.

The undo mld-snooping lastmember-queryinterval command restores the default interval.

By default, a querier sends group-specific or source-and group-specific Query messages at an interval of 1s.

Format

mld-snooping lastmember-queryinterval lastmember-queryinterval

undo mld-snooping lastmember-queryinterval

Parameters

Parameter	Description	Value
lastmember-queryinterval	Sets an interval at which a querier sends group-specific or source-and group-specific Query messages.	The value is an integer ranging from 1 to 5, in seconds.

Parameter

Description

Value

lastmember-queryinterval

Sets an interval at which a querier sends group-specific or source-and group-specific Query messages.

The value is an integer ranging from 1 to 5, in seconds.

Views

VLAN view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
l2mc	write

Usage Guidelines

Usage Scenario

The mld-snooping lastmember-queryinterval command provides the following functions:

Sets an interval at which a querier sends group-specific or source-and group-specific multicast group Query messages.
After the querier function is enabled, run this command to set a shorter interval if multicast group members change frequently. The device can then rapidly respond to users' requests.
Adjusts the aging time of member interfaces.
After receiving an MLD Snooping Done message from a host, a device sets the aging time of the corresponding member interface based on the following formula: Member interface aging time = Interval at which group-specific or source-and group-specific Query messages are sent x Number group-specific or source-and group-specific multicast group Query messages to be sent. By default, the device sets the aging time to 2s. To adjust the aging time, run the mld-snooping lastmember-queryinterval command to set the message sending interval, and run the mld-snooping robust-count command to set the number of group-specific or source-and group-specific multicast group Query messages to be sent.
If the querier receives a Report message for the multicast group from another host within the robust-count x lastmember-queryinterval period, it continues to maintain the member interface information for the group. Otherwise, the querier considers that there is no member of the group on the network segment, and does not maintain the member interface information for the group any more.

Prerequisites

MLD snooping has been enabled globally and in the VLAN view.

Configuration Impact

If the mld-snooping lastmember-queryinterval command is run more than once in the same VLAN view, the latest configuration overrides the previous one.

Precautions

To use the mld-snooping lastmember-queryinterval command configuration as a factor of adjusting the member interface aging time, set the same interval as that specified on its upstream device. Otherwise, multicast data transmission will be interrupted between the Layer 2 and Layer 3 devices.

The

mld-snooping lastmember-queryinterval command fails to be run in a VLAN or VSI view in any of the following conditions:

A dot1q termination sub-interface is added to the VLAN.
The VSI is bound to a BD.

Example

# Configure the querier in VSI aa to send group-specific or source-and group-specific Query messages at an interval of 4s.

<HUAWEI> system-view
~HUAWEI> mld-snooping enable
[*HUAWEI] mpls
[*HUAWEI-mpls] quit
[*HUAWEI] mpls l2vpn
[*HUAWEI-l2vpn] quit
[*HUAWEI] vsi aa
[*HUAWEI-vsi-aa] pwsignal ldp
[*HUAWEI-vsi-aa-ldp] vsi-id 1
[*HUAWEI-vsi-aa-ldp] quit
[*HUAWEI-vsi-aa] quit
[*HUAWEI-vsi-aa] mld-snooping lastmember-queryinterval 4

# Configure the querier in VLAN 2 to send group-specific or source-and group-specific Query messages at an interval of 2s.

<HUAWEI> system-view
[~HUAWEI] mld-snooping enable
[*HUAWEI] vlan 2
[*HUAWEI-vlan2] mld-snooping lastmember-queryinterval 2