igmp-snooping suppress-time

Function

The igmp-snooping suppress-time command sets the IGMP message suppression time in a VLAN.

The undo igmp-snooping suppress-time command restores the default IGMP message suppression time in a VLAN.

By default, the IGMP message suppression time is 10 seconds.

Format

igmp-snooping suppress-time suppress-time

undo igmp-snooping suppress-time

Parameters

Parameter	Description	Value
suppress-time	Specifies the IGMP message suppression time in a VLAN.	The value is an integer that ranges from 0 to 300, in seconds. The value 0 indicates that IGMP messages are not suppressed.

Views

VLAN view

Default Level

2: Configuration level

Usage Guidelines

Usage Scenario

To reduce the IGMP messages sent from a Layer 2 device to the upstream Layer 3 device and protect the Layer 3 device from attacks, enable the Layer 2 device to suppress IGMP Report and IGMP Leave messages sent by hosts in a VLAN. After this function is enabled, the Layer 2 device processes IGMP Report and IGMP Leave messages as follows:

After receiving an IGMP Report/Leave message and forwarding the message, the Layer 2 device does not forward the same type of messages to the router port within the suppression time.
If the Layer 2 device receives an IGMP General Query message or Group-Specific message, it does not suppress the first IGMP Report message that responds to the General Query message. In addition, the Layer 2 device resets the suppression timer when it receives the first IGMP Report message.

Prerequisites

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

Follow-up Procedure

Run the igmp-snooping max-response-time command to set the maximum response time for General Query messages. It is recommended that the suppression time be the same as the maximum response time for IGMP Query messages in a VLAN.

Precautions

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

The configured suppression time is invalid for IGMPv3 messages.

Example

# Set the IGMP message suppression time in VLAN 2 to 15 seconds.

<HUAWEI> system-view
[HUAWEI] igmp-snooping enable
[HUAWEI] vlan 2
[HUAWEI-vlan2] igmp-snooping enable
[HUAWEI-vlan2] igmp-snooping suppress-time 15