The ipv6 nd dad attempts command sets the number of times NS packets are sent when the system performs Duplicate Address Detection (DAD).
The undo ipv6 nd dad attempts command restores the default value.
By default, the number of times NS packets are sent when the system performs DAD is 1.
| Parameter | Description | Value |
|---|---|---|
| value | Specifies the number of times NS packets are sent when the system performs DAD. | The value is an integer that ranges from 0 to 600. The default value is 1, which is recommended. |
Usage Scenario
When you configure an IPv6 address (a global unicast address or a link-local address) for an interface, check whether other interfaces connected to this interface have used the IPv6 address to be configured to prevent address conflicts. The default number of detection times is recommended. If there is a long link delay, you can increase the number of detection times. When a loopback address is configured for an interface, the loopback address may fail the address conflict detection. In this case, you can set the number of detection times to 0 to disable detection, allowing the loopback address to be used.
Prerequisites
The IPv6 function has been enabled on the interface using the ipv6 enable command in the interface view.
Precautions
If the number of times NS packets are sent when the system performs DAD is set 0, DAD is prohibited.
If the physical link connected to an interface fails, DAD cannot be performed on the interface.
If the ipv6 nd dad attempts command has been run, running the ipv6 nd ra command will change the number of configured detection times.
DAD transmits node configuration variables. The system automatically determines the time to send neighbor request messages while DAD is performed to detect a tentative unicast IPv6 address.
# Set the number of times NS packets are sent when the system performs DAD to 20 on VLANIF100.
<HUAWEI> system-view [HUAWEI] ipv6 [HUAWEI] interface vlanif 100 [HUAWEI-Vlanif100] ipv6 enable [HUAWEI-Vlanif100] ipv6 nd dad attempts 20
# Set the number of times NS packets are sent when the system performs DAD to 20 on GE0/0/1.
<HUAWEI> system-view [HUAWEI] ipv6 [HUAWEI] interface gigabitethernet 0/0/1 [HUAWEI-GigabitEthernet0/0/1] undo portswitch [HUAWEI-GigabitEthernet0/0/1] ipv6 enable [HUAWEI-GigabitEthernet0/0/1] ipv6 nd dad attempts 20