mld-snooping max-response-time

Function

The mld-snooping max-response-time command sets the maximum response time for MLD General Query messages in a VLAN.

The undo mld-snooping max-response-time command restores the maximum response time for MLD General Query messages in a VLAN to the default value.

By default, the maximum response time for MLD Listener Query messages is 10 seconds.

Format

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

undo mld-snooping max-response-time

Parameters

Parameter	Description	Value
max-response-time	Specifies the maximum response time for General Query messages.	The value is an integer that ranges from 1 to 25, in seconds. The default value is 10.

Views

VLAN view

Default Level

2: Configuration level

Usage Guidelines

Usage Scenario

Setting MLD snooping parameters helps improve the multicast forwarding performance on the switch. By setting the maximum response time for MLD General messages, you can:

Control the deadline for a host to send a Report message. When hosts are required to respond to Query messages quickly, set a short maximum response time. To avoid congestion caused by a large number of Report messages sent by hosts, set a long maximum response time.
Adjust the aging time of member ports. When the switch receives a Report message from a host, it starts the aging timer for the corresponding 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. This command sets the maximum response time in the formula. The number of times General Query messages are sent is set by the mld-snooping robust-count command, and the general query interval is set by the mld-snooping query-interval command.

The switch sets the maximum response time field in General Query messages to the value configured by the mld-snooping max-response-time command.

Prerequisites

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

Follow-up Procedure

Perform the following operations to improve multicast performance:

Run the mld-snooping query-interval command to set the interval at which General Query messages are sent.
Run the mld-snooping last-listener-query-interval command to set the interval at which Multicast-Address-Specific Query messages are sent.

Precautions

To make the configured maximum response time effective in a VLAN, run the mld-snooping enable command to enable MLD snooping in the VLAN.

The interval at which General Query messages are sent must be longer than the maximum response time for General Query messages. Otherwise, the switch will delete multicast memberships that should not be deleted.

Example

# Set the maximum response time for General Query messages in VLAN 3 to 20 seconds.

<HUAWEI> system-view
[HUAWEI] mld-snooping enable
[HUAWEI] vlan 3
[HUAWEI-vlan3] mld-snooping enable
[HUAWEI-vlan3] mld-snooping max-response-time 20