mld-snooping max-response-time

Function

The mld-snooping max-response-time command sets the maximum time for a querier to wait for responses from downstream hosts.

The undo mld-snooping max-response-time restores the default value.

By default, the maximum time for a querier to wait for responses from downstream hosts is 10s.

Format

mld-snooping max-response-time max-response-time

undo mld-snooping max-response-time

Parameters

Parameter	Description	Value
max-response-time	Sets the maximum time for a querier to wait for responses from downstream hosts.	The value is an integer ranging from 1 to 25, in seconds.

Parameter

Description

Value

max-response-time

Sets the maximum time for a querier to wait for responses from downstream hosts.

The value is an integer ranging from 1 to 25, 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 max-response-time command provides the following functions:

Sets the maximum time for a querier to wait for responses from downstream hosts.
After the querier function is enabled, if you want hosts to rapidly respond to the querier, set a smaller value for ; if you want to prevent traffic congestions caused by frequently sent response messages, set a larger value for .
Ensure that is smaller than the interval at which general Query messages are sent; otherwise, multicast group member entries may be deleted incorrectly.
Adjusts the aging time of member interfaces.
After receiving an MLD Report message from a host, a device sets the aging time of the corresponding member interface based on the following formula: Member interface aging time = Number of group-specific Query messages to be sent x Interval at which general Query messages are sent + Maximum time for a querier to wait for responses from downstream hosts. By default, the device sets the aging time to 130s. To adjust the aging time, run the mld-snooping max-response-time command to set the maximum time for a querier to wait for responses from downstream hosts, run the mld-snooping robust-count command to set the number of group-specific Query messages to be sent, and run the mld-snooping query-interval command to set the sending interval of general Query messages.

Prerequisites

MLD snooping has been enabled using the mld-snooping enable command.

Configuration Impact

If the mld-snooping max-response-time command is run more than once in the same view, the latest configuration overrides the previous one.

Precautions

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

The maximum time for a downstream host to respond to a querier fails to be set in a VLAN in any of the following situations:

The VLAN is bound to a VSI.
The
mld-snooping max-response-time command fails to be run in a VSI view in the following condition:
The VSI is bound to a BD.

Example

# Set the maximum time for a querier in VLAN 100 to wait for responses from downstream hosts to 20s.

<HUAWEI> system-view
[~HUAWEI] mld-snooping enable
[*HUAWEI] vlan 100
[*HUAWEI-vlan100] mld-snooping max-response-time 20