Reader Walt Czeka's iPad has suddenly turned a blind eye to his local network. He writes:
After using my iPad for a short time this morning it suddenly wouldn't recognize my AirPort network, even after I switched it off and on. I picked up my iPhone and it sees the network perfectly well so I don't think it's a network problem. What should I do?
There are a variety of things you can try and they work with any router. The first (and the one most likely to meet with success) is to shut off your iPad, pull the power plug on your AirPort base station to power it down, wait half a minute or so, plug the base station back in, wait for its green light to shine, and then switch on the iPad. This can clear out some funk in the routing portion of the base station, which allows your iPad's network connection to return.
If this doesn't work because the iPad's the funky character in this passion play, you can fiddle with a couple of its settings. First, go to Settings > Wi-Fi and toggle the Wi-Fi switch Off and then back on again.
No success? Tap the blue dot icon to the right of your network's name in this same Wi-Fi pane and tap Forget This Network. Move back to the Wi-Fi page, tap your network's name, enter its password, and hope that this time it takes.
Still no? Travel to the General setting, swipe down to the bottom of the screen, tap Reset, and tap Reset Network Settings. Confirm your choice by tapping Reset in the window that appears. Your iPad will reboot. Once it has, return to the Wi-Fi setting, tap on your network's name, enter its password, and join in.
And then there are the more esoteric fixes--changing the channel on your router and switching the router's security scheme. But given that your iPhone sees the network I'll guess with a strong sense of confidence that you won't need to go that far.