The following article discusses the source of the 192.42.249.12 address seen on AirPort Base Station.

192.42.249.12 is the default address for a new base station. It is also the address assigned after a soft reset or after updating the software on the Base Station.

Note: The 192.42.249.13 address will be seen after performing a hard reset and before uploading the software into the base station.

You will also see this 192.42.249.12 when the base station is not assigned a static IP address and it is unable to receive one dynamically from a DHCP server or a dial-up Internet service provider.

Why Not a 169.254.x.x Address?

First, the base station was not equipped with the algorithm to generate such an address. Secondly, it was not designed to behave like a Macintosh computer in this manner. When the AirPort Base Station is started up, it is preset to try to obtain an IP address from a DHCP server. If no DHCP server responds, the base station will default back to the 192.42.249.12 address.

Even though the AirPort Base Station is initially setup to look for a DHCP server, it will default to 192.42.249.12 address if one cannot be found). The 192.42.249.12 address is a clue that your base station does not see a DHCP server on your network. It would be a good idea to look for any basic connectivity issues at this point, such as bad or improper cabling. If you're not even using DHCP or attempting to use a dial-up connection, this means that you have not programmed your base station and need to run the AirPort Setup Assistant.

Why Then, the 192.42.249.12 Address?

This 192.42.249.12 address is a globally valid IP address arbitrarily assigned to the base station by Apple.

How to Access a Base Station with a 192.42.249.12 address?

If you are having difficulties using the AirPort Admin Utility to reconfigure an AirPort Base Station with the 192.42.249.12 address, you have two alternate methods to access it.

These methods require that you make changes to the TCP/IP control panel or change the IP address of the computer trying to access the Base Station.

Method 1: Change the method of connection in the TCP/IP control panel.

1. Open the TCP/IP control panel and change the configuration from AirPort to PPP.

2. Close and save the setting in the TCP/IP control panel.

3. Open the TCP/IP control panel and change it back to AirPort and Using DHCP. The fields for IP Address, Subnet mask; and Router Address will say "< will be suppled by server >".

4. Close and save the settings.

For additional information, refer to article 58618: " AirPort: Reason for 169.254.xxx.xxx IP Address ".

Note: Wireless Internet access requires AirPort Card, AirPort Base Station, and Internet Access (fees may apply). Some ISPs are not currently compatible with AirPort, including America Online. Range may vary with site conditions.