If your ATT wifi not working for any reason then you must contact to ATT live service experts.
How to fix the Att wifi problem?
If your ATT wifi not working for any reason then you reset your gateway to counter this problem. The reset button is generally located at the back of the router. All you need to press it for a few seconds until the notification LED’s turned off. Feel free to have a word with ATT customer care experts if you have any doubt in that regard.
