When I launch the AirPort Setup Assistant, I see an error message stating that the required AirPort hardware can't be found.
The AirPort software requires that you have an AirPort card installed on the machine you use to configure a HAP base station. If an AirPort card is not found, the software won't run.
If you don't have an AirPort card installed in your Mac, you need to do so before running the AirPort Setup Assistant.
If you do have an AirPort card installed, it is not properly installed. Repeat the installation steps to ensure that the card is properly installed.
To learn how to install an AirPort card, see "Installing an AirPort Card," p. 318.
When I try to configure a base station manually, I get an error stating that the base station can't be configured.
This problem can occur for various reasons. First, try resetting the base station (see the next section). If that doesn't work, try opening the AirPort Setup Assistant and configuring the base station using the assistant. Then, go back into the AirPort Admin Utility and try to configure the base station again. This sometimes clears the error.
I can't access the base station because I don't know its password.
When you have trouble with an AirPort HAP, you can reset it to its factory defaults by inserting a paper clip into the reset button hole on the bottom or back of the unit. Hold down the button for 5 seconds and the base station is reset?all settings are returned to the default and the password becomes public.
My AirPort signal strength is low. Or, I can't find the network to which I want to connect.
Two primary factors affect the strength of the AirPort signal your Mac receives from a base station (hardware or software) or from Macs providing a computer-to-computer network. One is the distance from the base station to your Mac; the other is the amount of interference in the area.
If your Mac is within 150 feet of the base station you want to use, there should be no trouble getting a strong enough signal. If you are at the edge of or beyond that range, move your Mac closer to the base station or move the base station closer to you. You can also try repositioning the base station because it can sometimes be affected by materials or other fields between it and your Mac.
If you are close to the base station but can't get a strong signal, try changing the frequency of the network in the event that it is being interfered with by another signal of some type.
To learn how to change an AirPort network's frequency, see "Configuring a Base Station Manually," p. 307.
If you use an AirPort Extreme base station with an antenna port, you can add an antenna to extend its range. You can also daisy-chain base stations together.
To learn how to use WDS, see "Making AirPort Go Farther," p. 326.
My Mac is connected to an AirPort network, but I can't access the Internet.
If you are connecting to the Internet through a HAP, the most likely cause is that the access point has lost its Internet connection. Use some means to confirm that Internet services are available to the base station, such as by using a machine connected independently or calling your service provider. If services are available, use the AirPort Admin Utility to check its configuration to ensure that it is correct. If all else fails, reset the access point.
If you are connecting through a network provided by a Mac acting as a base station, make sure that the Mac is still running and that its firewall is not turned on. The Mac OS X firewall blocks access to the Internet from machines attempting to use it in that way.
It is also possible that the base station Mac went into Sleep mode. If so, wake it; then quit any Internet applications on the machine with which you are trying to connect to the Internet and restart them.
If that doesn't work, restart the machine itself and try again.
If none of these steps works and you have a broadband modem connected to the base station that provides DHCP services, use the following steps to attempt to reset the connection:
Unplug the modem for at least 20 seconds, and then plug it back in again. This forces the modem to get a new address.
Reset the base station by pressing its reset button for 5 seconds.
Open the AirPort Setup Assistance and select the Join an Existing Network option.
Follow the onscreen instructions to update the base station.