Try unplugging it and plugging it back in.
If your AirPort Extreme stops responding completely, you may need to reset it to the
factory default settings.
Resetting your AirPort Extreme to factory default settings erases all
of your base station settings and resets them to the settings that came with your
To return your AirPort Extreme to the factory settings:
Use the tip of a ballpoint pen to press and hold down the reset button until the status
light flashes quickly (about 5 seconds).
The AirPort Extreme resets with the following settings:
The AirPort Extreme receives its IP address using DHCP.
The network name reverts to Apple Network XXXXXX (where XXXXXX is replaced
with the last six digits of the AirPort ID).
The base station password returns to public.
If your base station is still not responding, try the following:
Unplug your AirPort Extreme.
Use the tip of a ballpoint pen to hold down the reset button while you plug in your