igmp-snooping max-response-time

Function

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

The undo igmp-snooping max-response-time command restores the default maximum response time for IGMP General Query messages in a VLAN.

By default, the maximum response time for IGMP General messages in a VLAN is 10 seconds.

Format

igmp-snooping max-response-time max-response-time

undo igmp-snooping max-response-time

Parameters

Parameter	Description	Value
max-response-time	Specifies the maximum response time for IGMP 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 IGMP snooping parameters helps improve the multicast forwarding performance. By setting the maximum response time for IGMP General Query messages, you can:

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

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

Prerequisites

IGMP snooping has been enabled globally using the igmp-snooping enable (system view) command.

Follow-up Procedure

Perform the following operations to improve multicast performance:

Run the igmp-snooping query-interval command to set the interval at which General Query messages are sent.
Run the igmp-snooping lastmember-queryinterval command to set the interval at which Group-Specific Query messages are sent.

Precautions

The configuration takes effect only after you run the igmp-snooping enable (VLAN view) command to enable IGMP snooping in the VLAN.

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

Example

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

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