# Configuring Duplicate Address Detection Attempts

The duplicate address detection feature helps to verify that a new unicast IPv6 address is unique in the network. The router sends the IPv6 address in its neighbor solicitation messages. However, the router relies on the receiving device to understand the address duplication and does not prompt a conflict if the address already exists.

The CLI allows you to specify the number of consecutive neighbor solicitation messages that the router sends from the IPv6 interface.

ipv6 nd dad attempts

- Use to specify the number of consecutive neighbor solicitation messages that the router sends from the IPv6 interface.

- Use an attempt value of zero (0) to disable duplicate address detection on the current interface.

- The router suspends duplicate address detection on interfaces that are administratively down.

- Example
  host1(config-if)#ipv6 nd dad attempts 10

- Use the no version of this command to restore the default number of attempts to one (1).
- See ipv6 nd dad attempts