That's not an option. That option only works for "Choose a Network...". If you touch the right arrow the next screen is titled "AirPort Setup". The message you get is "The AirPort Extreme named "Apple Network a94b6f" cannot be set up by this software. Go to apple.com.support.airport for more information." The only option at the top is "Cancel".
I am not wanting to setup the AirPort, it is already setup and working fine.
How can I get the iPhone to forget the AirPort Extreme
If you never joined/set up the Airport extreme network on your phone, how can you "forget it"???
What I suggested is how to forget networks that have already been found and joined. If you haven't joined/connected, there is nothing to forget - which begs the question what you actually want to do.
If what you actually want is for your phone not to see or show it, there are 2 possiblities:
1. Settings > WiFi > Ask to Join Networks > OFF
2. Set your Airport Extreme to not broadcast its SSID.
The AirPort Extreme doesn't show up as a network, so no I can't "forget it". Maybe my terminology is not correct...
What I want is for my iPhone to stop automatically selecting the AirPort Extreme network when I walk back into the house after going into town. I'll access some wifi network at a variety of locations during almost any trip into town.
I can simulate the problem by setting the "Ask to Join Networks" to OFF and restarting the iPhone. I took some screen shots from the phone, but I can't get them to upload to this site.
I don't think setting my AirPort Extreme to not broadcast its SSID is a valid solution. I still need to be able to select this network from my MacBook Pro and Mac Pro to be able to print.
I've had my iPhone for a couple of years and have not had this problem until recently. I'm not sure exactly when is started and if it start shortly after the latest iOS update.
The AirPort Extreme doesn't show up as a network, so no I can't "forget it"
What I want is for my iPhone to stop automatically selecting the AirPort Extreme network when I walk back into the house after going into town.
I can simulate the problem by setting the "Ask to Join Networks" to OFF
This makes no sense since the phone does not "select" any network it hasn't previously joined and it will only display it as an option to join if "Ask to Join Networks" is ON. There must be something corrupted in the WiFi network settings for this to happen as you describe.
Try the following troubleshooting steps as needed:
1. Reset phone (no data loss): press both home and power buttons for at least 10 seconds, releasing when the Apple logo appears.
2. Settings > General > Reset > Reset Network Settings. You will have to rejoin all WiFi networks.
3. Restore phone in iTunes using a backup
4. Restore in iPhone as new (without using a backup).