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How to fix Gateway Authentication Failure error?

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  • 4 min read

If you’re trying to connect to the internet using a U-verse router, at times, you might encounter an authentication failure error. The error indicates either an error in your router’s configuration or a build-up of corrupt launch configurations by the router. 

In some cases, your router might even get corrupted because of sudden shutdowns, which can prevent it from connecting to the internet.

In this article, we’re looking at several fixes that can get rid of the issue. Also, since these fixes are mostly generic in nature, you can try them on any other router to resolve any connectivity issues you’re facing. 

Also read: What is a Router and how does it work?

Power cycle your router

One possible cause of the issue is when the internet cache built by the router over time gets corrupted. To reset this cache, we’re going to have to power cycle the router. 

Step 1: Unplug your router from the wall socket.

Step 2: Hold down the power button for at least 15 seconds. 

Step 3: Plug the router back in and turn on the power.

This is one of the easiest fixes that can get just about any router up and running. 

Also read: How are gaming routers different from regular ones? Top 5 gaming routers

Reset the router

If power cycling your router didn’t fix the issue, try resetting your router to set all settings back to default. There are two ways you can reset routers.

  • Using the router’s firmware.
  • Using the reset button on the router itself.

Using the router’s firmware

To reset a router using its firmware, you’re going to have to log in to your router using the default IP address of your network. For a U-verse router, the IP will most likely be

Type in your browser’s search bar >> press Enter >> Settings >> Diagnostics >> Reset >> Reset to Factory Default State.

Wait for the browser to restart and it should configure itself just fine. 

Using the reset button

For this method, the first thing you’re going to have find is a small pin or anything small enough to insert in the router’s reset switch hole. Once you have it, put the pin in, wait for around 15-20 seconds and wait for the router to reset.

The router should automatically configure itself and establish a connection with the server. Now check to see if your issue is resolved. 

Also read: How to turn an old router into a repeater?

Check the ONT port

The error is likely to occur if there’s a connection fault at the ONT port. Check if you have the ethernet connection on the right ONT port. Ensure that the cable is properly inserted in the port and that there are no faults with the cable itself.

What is WiFi 6 (802.11ax): Everything you need to know

You can refer to the user guide provided with the router/modem to check the right ONT port for you. 

Check for an outage

Another possible reason for the issue could be an outage at AT&T’s end. In such cases, all you can do is contact your service provider for an exact ETA when services resume.

Alternatively, you can log on to the MyATT website using your member ID and password and run a diagnostic test yourself. 

Also read: What is the difference between Router and Switch?


Yadullah Abidi

Yadullah is a Computer Science graduate who writes/edits/shoots/codes all things cybersecurity, gaming, and tech hardware. When he's not, he streams himself racing virtual cars. He's been writing and reporting on tech and cybersecurity with websites like Candid.Technology and MakeUseOf since 2018. You can contact him here: