How To Fix Gateway Authentication Failure

Gateway is a device that is used to connect two networks. In the current scenario, because of integrated functionality, network devices like routers, ONUs, and even modems are widely known as gateway devices.

If you are a user of the AT&T U-Verse Modem, you might be facing the Gateway Authentication Failure error. It occurs when your credentials can’t be verified on the AT&T network.

Now, without further ado, let’s look at the possible causes and solutions for this issue.

Causes for Gateway Authentication Failure

Troubleshooting Gateway Authentication Failure

There is not much you can do from your end except verify the physical integrity of your device along with all the connectors. You can always get in touch with the support personnel.

Here are some of the probable fixes you can try when you get the Gateway Authentication Failure error:

Power Cycle the Modem

The first method you should try is to cycle the power on the gateway. It clears the router cache and allows it to select the least crowded channel for a new connection. Doing so will fix the Gateway Authentication Failure error if there aren’t any other issues.

Please follow the steps below to power cycle your modem:

1. Turn the modem off by disconnecting the power supply cord.
2. Plug out all the cable connections and wait for a few minutes.
3. Plug the cables back in and turn the modem on.

Reset the Gateway

The next method you can try is to factory reset your gateway modem. Doing so will return all settings to the default state. So, you’ll need to re-enter your login info and set up your wireless network again.

There are two ways to reset the gateway. You can pick one according to your preference.

Reset Through the Modem

1. Locate the Reset button on the rear side of your modem.
2. Press the button for 20-30 seconds to reset your modem. You’ll need a pin or a toothpick for this.
   

Reset Using a Browser

1. Open a browser while connected with the modem.
2. Enter the default Gateway IP on the browser. 
3. For 2Wire/Pace Gateway, go to Settings > Diagnostics > Resets and select Reset to Factory Default State.
   
4. For NVG Gateway, go to Diagnostics > Resets and select Reset Device.
   
   

After resetting the gateway, please make the necessary changes in the settings or restore them from automatic backup.

Check Connections

This error can also occur as a result of loose connections. Please disconnect and properly reconnect all cables. To maintain a direct cable connection, you can also remove surge protectors, battery units, etc.

Many users have also suffered from this issue because they accidentally connected their cable to the wrong ONT port. So, please make sure to use the correct ONT port to plug in the cable. 

You can check in the user guide for the modem if you need to know which port is correct. On the 5268 Modem, the red/orange ONT port is the correct one.

Use the Online myAT&T Support Feature

Another solution is to use the self troubleshooting feature in the myAT&T website. You can check the probable reason and some simple fixes through this method. While the fixes are similar to those we have mentioned previously, using this feature is a good way to determine if the issue is due to a power outage.

In such a case, you can only wait for the power to restore or contact support.

Here’s how to use the troubleshooting feature:

1. Open the online ATT Internet Support on your browser.
2. Under Fix my internet, click on Sign in to start.
   
3. Enter your credentials and log in to your account.
4. Follow the on-screen troubleshooting instructions.

You can also perform this method through the myAT&T app on your smartphone.

Contact Service Provider

You can try contacting the AT&T service provider if you can’t fix the problem by applying the previous methods. Your account may not have been properly provisioned for your gateway. Or, some broken cables might be preventing the connection.

The AT&T support will check and fix any problems on their end. If the issue is with your end, they’ll most likely send a technician to your location to determine the exact reason for your problem and fix it.

Replace the Gateway

If the problem is with your modem, you’ll need to replace it. Sometimes you can get the AT&T technician to install a new gateway modem. Whilst most of the times, you’ll need to install it by yourself.

To do so, first, make a note of all the cable arrangements in the old modem, then connect each cable to the new one accordingly.

You can also use the user guide for this process. Finally, turn on your modem and wait for all the status lights to turn solid green. 

How to Restore My Gateway Settings After a Factory Reset?

If you have enabled automatic backups of your gateway settings, you can directly restore them instead of manually changing your settings after a reset. Here’s how you can do so:

1. Go to the AT&T restore website on your browser.
2. Log in with your Member ID and Password.
3. Here, click on View Available Backups.
4. Look for the backup you wish to restore and select Restore.
5. Pick View Details to look for the backup details.
6. Finally, choose Restore This to restore your gateway settings.

Restart your Wi-Fi devices to apply the settings in those devices.

How to Check the Default Gateway IP?

You’ll likely find the default Gateway IP on the modem itself. If not, you can use the command-line interface to check your network configuration and determine the address.

On Windows

1. Open the run dialog box (Win + R) and enter cmd.
2. In the Command Prompt, type ipconfig and press Enter.
3. Look for Default Gateway to determine its address.
   

On Mac

1. Launch the spotlight search (Command + Spacebar).
2. Search for Terminal and open it.
3. Type netstat -rn and press Enter.
   
4. Look for the address under Gateway and on the side of default.

Hopefully, this article helps you solve the gateway authentication failure problem on your AT&T connection.