savi max dad-prepare-delay

Function

The savi max dad-prepare-delay command sets the time for listening to the duplicate address detection performed by the DHCPv6 client.

The undo savi max dad-prepare-delay command restores the default setting.

By default, the time for listening to the duplicate address detection performed by the DHCPv6 client is 2 seconds.

Format

savi max dad-prepare-delay value

undo savi max dad-prepare-delay

Parameters

Parameter	Description	Value
value	Specifies the time for listening to the duplicate address detection performed by the DHCPv6 client.	The value is an integer that ranges from 1 to 100, in seconds.

Views

System view

Default Level

2: Configuration level

Usage Guidelines

Usage Scenario

The savi max dad-prepare-delay command is applicable only for DHCPv6-Only scenarios and DHCPv6+SLAAC scenarios.

After detecting that the DHCPv6 client obtains the IPv6 address, the device detects whether the DHCPv6 client sends an NS packet for duplicate address detection.

In DHCPv6-Only scenarios:
- If no NS packet in the DAD process is detected in the configured listening period, the device sets the DHCPv6 snooping entry to the bound state. It indicates that the DHCPv6 does not perform the duplicate address detection on the obtained IPv6 address or no duplicate IPv6 address exists.
- If an NS packet in the DAD process is detected in the configured listening period, the device does not change the status of the mapping DHCPv6 snooping entry. The device sets the DHCPv6 snooping entry to the bound state only when the listening period expires.
In DHCPv6-Only scenarios, when detecting the DHCPv6 Decline packet or DHCPv6 Release packet from the DHCPv6 client, the device deletes the corresponding DHCPv6 snooping entry.
In DHCPv6+SLAAC scenarios:
- If no NS packet in the DAD process is detected in the configured listening period, the device sets the DHCPv6 snooping or ND snooping entry to the bound state. It indicates that the client does not perform the duplicate address detection on the obtained IPv6 address or no duplicate IPv6 address exists, and the client can use this IPv6 address.
- If an NS packet in the DAD process is detected in the configured listening period, the device sets the mapping DHCPv6 snooping or ND snooping entry to the detection state, and listens to the mapping NA packet. For the listening method, see savi max dad-delay.

Prerequisites

The SAVI function has been enabled using the savi enable command.

Precautions

This command is used together with ND snooping and DHCPv6 snooping.

Example

# Set the time for listening to the duplicate address detection performed by the DHCPv6 client to 5 seconds.

<HUAWEI> system-view
[HUAWEI] savi enable 
[HUAWEI] savi max dad-prepare-delay 5