Connect to the Internet using DHCP in AirPort Utility on Mac
When you use AirPort Utility Setup Assistant to set up your new base station or extend an existing network, it automatically configures the best settings for your network. It’s recommended that you manually configure your base station’s settings only if instructed to do so by your ISP or network administrator.
Open the AirPort Utility app on your Mac, located in the Utilities folder in the Applications folder.
In the graphical overview, select the base station you want to configure, then click Edit. You may need to enter a password for the base station.
Click Internet, click the Connect Using pop-up menu, then choose DHCP.
Important: Don’t modify the DNS Servers, IPv6 DNS Servers or Domain Name fields or click the Renew DHCP Lease button unless you’re instructed to do so by your ISP or network administrator.
Click Update to save your changes.