If you did not enter the DNS information while in the setup assistant, you need only open the TCP/IP control panel and enter it there and then run the AirPort Setup Assistant. Figure 1 shows an example of the PPP section of the TCP/IP control panel.
Figure 1. TCP/IP control panel
Note: This information can also be entered during setup of your Base Station using the AirPort Setup Assistant.
Note: Wireless Internet access requires an Internet service provider (fees may apply) and AirPort (or AirPort-compatible) wireless Ethernet card and base station. Some ISPs are not compatible with AirPort. For more information, see technical document 106590: "AirPort: Requirements for Wireless Internet Access"