nd snooping wait-time life-time

Function

The nd snooping wait-time life-time command configures the wait time for a device to send an NS packet to detect the user status and the lifetime of an ND snooping binding entry when a device detects the user status.

The undo nd snooping wait-time life-time command restores the default settings.

By default, the wait time for a device to send an NS packet to detect the user status is 250 milliseconds and the lifetime of an ND snooping binding entry when a device detects the user status is 500 milliseconds.

Format

nd snooping wait-time wait-time life-time life-time

undo nd snooping wait-time life-time

Parameters

Parameter	Description	Value
wait-time	Specifies the wait time for a device to send an NS packet to detect the user status.	The value is an integer that ranges from 1 to 5000, in milliseconds. The default value is 250 milliseconds.
life-time	Specifies the lifetime of an ND snooping binding entry when a device detects the user status.	The value is an integer that ranges from 1 to 10000, in milliseconds. The default value is 500 milliseconds.

Views

System view

Default Level

2: Configuration level

Usage Guidelines

Usage Scenario

A device updates the ND snooping binding table by detecting the received NA packets. If an ND snooping binding entry exists and the device receives an NA packet with the IP address the same as that in the corresponding entry and inbound port number different from that in the entry, the NA packet conflicts with the entry. The device is then triggered to send an NS packet to detect whether the user corresponding to the entry is online. You can run the nd snooping wait-time wait-time life-time life-time command to configure the wait time for a device to send an NS packet to detect the user status and the lifetime of an ND snooping binding entry when a device detects the user status.

If the entry is within the lifetime and the device receives an NA packet from the port corresponding to the entry, the user corresponding to the entry is still online and the device updates the IP address lease in the corresponding entry.
If the entry is within the lifetime and the device does not receive an NA packet from the port corresponding to the entry, the user corresponding to the entry is offline and the device updates the user's IP address lease time in the entry and updates the port number in the entry to that in the previously received NA packet.

Prerequisites

ND snooping has been enabled using the nd snooping enable command in the system view.

Precautions

After the device receives an NA packet conflicting with an ND snooping binding entry and user status detection is enabled, periodic user status detection is suspended.

Example

# Set the wait time for a device to send an NS packet to detect the user status to 300 milliseconds and the lifetime of an ND snooping binding entry when a device detects the user status to 2000 milliseconds.

<HUAWEI> system-view
[HUAWEI] nd snooping enable
[HUAWEI] nd snooping wait-time 300 life-time 2000