Troubleshoot Common AT&T Internet Problems (All Fixes)

AT&T Internet will not work when you will see a red light on the router’s broadband status light and sometimes, a blinking red light on service. Moreover, mobile data users also experience the problem. In the case of a broadband router, the lights may remain normal but the signals get dropped frequently. Due to drop signals, you cannot even load a single web page correctly on AT&T Internet and will see missing images/items on the page.

The issue is also reported after heavy rains or power surges in a particular area. Individuals who relocated also faced the issue when using up AT&T Internet in their vicinity. Occasionally, the problem occurs only with a single device. Also, there are instances when only Wi-Fi devices were affected whereas, Ethernet worked correctly.

In this article, we will discuss the causes of the AT&T Internet issue and how to fix it. But before moving on, make sure your AT&T account is registered if the router’s broadband light shows red.

Why Doesn’t AT&T Internet Work?

Outdated Carrier Settings: The carrier settings are used to provide data service on your mobile phone. If these settings are outdated, the data requests from your phone will not be compatible with the network provider and thus cause the issue.
AT&T Internet Security: You will experience the issue if AT&T Internet Security is blocking the access of your network or a device to the Internet.
IPv6 Incompatibility: If your devices are failing to comply with the IPv6 protocol requirements of AT&T, Internet connectivity may get limited.
Improper DNS Settings: AT&T Internet will stop working if the DNS settings of your network or device are not proper and as a result, the IP address of the required website will not be found.

1. Enable and Disable Network Communications of the Device

Your AT&T Internet will not work if the network modules of your device are in an error state and need a fresh start to re-establish communications. This can be fixed by disabling and enabling the device’s network communications.

Enable and Disable Airplane Mode on the iPhone

Launch the iPhone Settings and enable Airplane Mode.
Enable Airplane Mode on the iPhone
Wait for a minute and disable Airplane Mode. Check if the AT&T Internet is working properly.

Disable and Enable the Windows PC’s Network Connection

Right-click on the network or Wi-Fi icon in the PC’s system tray and select Network & Internet Settings.
Open Network and Internet Settings of the Windows PC
Scroll down to the bottom and click on Advanced Network Settings.
Open Advanced Network Settings in the Windows Settings
Disable the problematic network type (Wi-Fi or Ethernet) by clicking on Disable in front of the option.
Disable Wi-Fi Network Adapter in the Windows Settings
Wait for a minute and enable back the network type. See if the AT&T Internet is functioning properly.

2. Reinsert the SIM into the Mobile Phone

If your SIM card fails to acquire accurate data from the cell tower, you will not be able to access mobile data. To address this, reinsert the SIM card into your phone which will reestablish communication with the cell tower.

Remove the SIM card from the phone and wait for 5 minutes.
Remove SIM Card from iPhone
Insert back the SIM and check if the ATT Internet is working fine.

If that does not work, then make sure your phone is compatible with the AT&T network.

3. Restart the Problematic Device and Networking Equipment

AT&T Internet will fail to work if the communication modules of your device or networking equipment malfunction and need reinitialization. You can solve this by restarting your device and networking equipment.

In the case of a mobile phone, restart it and check if that resolves the issue.
If not, restart the AT&T router and check if that solves the problem.
If that is not the case or did not work, power off the device, unplug its power cable (for PC) or remove the device’s battery (if possible).
Unplug Your Router from the Power Source
Remove other devices connected to your device e.g., a DVR connected to a TV.
Power off the networking equipment (such as a router) and unplug its power cable.
Wait for 5 minutes and connect back the power cable of the networking equipment.
Power on the networking equipment and connect back all the devices. Now check if the issue is resolved.

4. Update the Carrier Settings of Your Phone

If your phone’s carrier settings are not up-to-date, it will be incompatible with AT&T’s cell tower and will be unable to establish an Internet connection using mobile data. In this scenario, updating the carrier settings to the latest version will solve the problem.

To do so on an iPhone:

Navigate to Settings > General > About.
If there is a Carrier update shown, tap on Update.
Open About in the General iPhone Settings
Once the update process completes, restart the iPhone and verify if AT&T Internet is working properly.
Update the Carrier Settings of Your iPhone

5. Clear the Alternate Mac Address (For Xbox)

Xbox utilizes the Alternate MAC address to communicate on a secure network that allows the device to be whitelisted based on its MAC address. However, if it is not required by the AT&T router in use, then it can create Mac Address duplication in the router settings and will cause the issue.

To address this, clear the Alternate Mac address of the Xbox.

Navigate to Profile and System > Settings > General > Network Settings > Advanced Settings.
Open Advanced Network Settings of Xbox
Select the Alternate Mac address and click on Clear.
Select Alternate Mac Address in the Advanced Settings of Xbox
Select Restart and once restarted, determine if the AT&T Internet is working correctly on the Xbox.
Clear Alternate Mac Address of Xbox

6. Update the Router’s Firmware

When a router’s firmware is outdated, it will not be compatible with the networking protocols utilized by the AT&T network. This will result in the inability to connect to the Internet using the network. In such a case, updating the router’s firmware to the most recent version will solve the problem.

Access the admin portal of the ATT router and log in.
Navigate to the AT&T Software Update tab and click on Check for Updates.
If a firmware update is available, install the update.
Once updated, restart the router and connected devices. See if the AT&T Internet problem is solved.

7. Disable IPv6 in the Router’s Settings

Not all applications, devices, and networks are compatible with IPv6 and will fail to communicate on the Internet when utilizing the IPv6 protocol of AT&T. Furthermore if AT&T’s IPv6 DNS servers are not functioning correctly, this might also contribute to the issue. In such a case, disabling IPv6 in the router’s settings will solve the problem.

Head to the admin portal of the ATT router and log in.
Navigate to Settings > LAN or Home Network > IPv6.
Disable IPv6 and save the changes.
Disable IPv6 in the ATT Router’s Settings
Restart the router along with connected devices and check if the AT&T Internet is working.
If this does not work, disable IPv6 in your device’s network settings and check if that solves the problem.

8. Disable AT&T Internet Security on the Router

AT&T Internet will not work properly on your devices if the router’s Internet security, due to a bug, the feature is not letting these devices access the Internet. You can confirm this by temporarily disabling the Internet security feature and see if this does the trick.

Warning:

Advance at your own risk as disabling Internet Security on the router may expose your devices, data, and network to threats.

Download and install the ATT Smart Home Manager app.
Launch the App and log in using your credentials.
Go to the App Preferences and disable ATT Internet Security.
Disable AT&T Internet Security
Restart the router with other connected devices and check if the AT&T Internet is operating properly.

If the issue persists and you are using VPN on any of the devices (not only on the problematic device) connected to the same AT&T network, check if disabling VPN on all the devices solves the problem.

9. Restore and Re-add the APN Settings on the Phone

Mobile devices utilize Access Point Name (APN) settings to connect to the Internet using mobile data. If these APN settings are no longer valid, the mobile device will fail to connect to the Internet through the AT&T network. Here, re-adding the APN settings on the phone will resolve the issue.

Usually, these settings are fetched automatically by the phone but sometimes manual addition is required. To do so on an Android phone:

Navigate to Settings > Wireless & Networks> Mobile Networks > Access Point Names.
Select Restore to Defaults. In some cases, you may need to tap on the three vertical ellipses to show the option.
Restore Access Point Names to the Defaults in the Android Phone Settings
Confirm to reset the phone’s APN settings and once done, restart your phone. Check if the AT&T mobile data problem is solved.
If not, steer to the APN settings of your phone and select Add a New APN.

Add the following:

Name                               NXTGENPHONE

APN                                NXTGENPHONE

Proxy                              Not set  

Port                               Not set

Username                           Not set 

Password                           Not set 

Server                             Not set 

MMSC                               http://mmsc.mobile.att.net       

MMS proxy                          mobile.att.net       

MMS port                           80            

MCC                                310         

MNC                                410         

Authentication type                None      

APN type                           default,mms,supl,hipri 

APN protocol                       IPv4      

Bearer                             Unspecified

For a 5G-capable Android phone, you may set the Name and APN options to ENHANCEDPHONE and keep other details as above.
Save the changes made and restart your phone. See if the Internet is working.
If not, set MNC to 280 in the phone’s APN settings and check if that resolves the issue.

10. Change the DNS Settings of the Devices

You will fail to connect to the Internet on AT&T if DNS (Domain Name Servers) is not configured correctly in your setup or if DNS servers are malfunctioning. This will not let the DNS servers return the queries from the client devices and thus cause the problem.

Here, changing the DNS settings of the devices or router will resolve the issue. To do so on a Windows PC:

Right-click on the Wi-Fi or network icon in the system’s tray and select Network and Internet Settings.
Scroll down to the bottom and select Advanced Network Settings.
Open More Network Adapter Options in the Related Settings section and right-click on your network adapter (like Wi-Fi).
Open More Network Adapter Options in the Windows Settings
Select Properties and double-click on Internet Protocol Version 4 (TCP/IPv4).
Open Properties of the Network Adapter
Select the radio button of the Use the Following DNS Server Addresses option and enter the following in the relevant DNS boxes:
```
Preferred DNS Server
8.8.8.8

Secondary DNS Server
8.8.4.4
```
Open Properties of Internet Protocol Version 4 (TCP IPv4)
Click on OK and check if the problem is solved.
Change the DNS Server of Your PC
If the issue persists, add the following as the IPv6 DNS servers and check if that resolves the issue:
```
2001:4860:4860::8888

2001:4860:4860::8844
```

If that does not work, check if changing the DNS in the router’s settings solves the problem but it may break the operation of AT&T Uverse devices if you are using them.

11. Reset the Network Settings

When your device’s network settings are invalid or overloaded with outdated data, you will experience issues with AT&T’s Internet. To resolve this, reset your device’s network settings to the defaults.

Remember to note down the network info (such as Wi-Fi credentials or APN settings) that may be required later.

For an iPhone

Navigate to Settings > General > Reset.
Reset the Network Settings of the phone and restart your iPhone.
Tap on Reset Network Settings on iPhone
Upon restart, join the iPhone to a Wi-Fi network or set up an ATT APN (if required), and see if the ATT Internet is working.

For a Windows PC

Right-click on the network or Wi-Fi icon in the system’s tray and select Network & Internet Settings.
Open Advanced Network Settings and select Network Reset.
Click on Reset Now and confirm to reset the network settings.
Open Network Reset in the Windows Settings
Once done, restart your PC and connect the PC to the ATT Internet. Check if the Internet is working.
Click on Reset Now in the Windows Network Settings
If that fails, make sure the default gateway address of your PC is set correctly (same as the Wi-Fi or pointing to your router), and check if that clears the ATT issue at hand.

If that did not work and the issue occurs on a car (like a Nissan car), check if resetting the car’s location settings solves the problem. If the problem occurs on a Mac, check if renewing the DHCP lease in Mac’s network preferences solves the issue.

12. Reset the Router to Factory Defaults

If your router’s firmware contains conflicting data with the AT&T network or is invalid, your Internet connection will not function properly. To solve this, reset your router to its default settings.

Do not forget to note the manual configuration which will be required after resetting the router. Alternatively, you can contact AT&T for assistance in obtaining the necessary settings for your router.

Press and hold the router’s reset button for at least 10 seconds.
Reset the ATT Router to Factory Defaults
Release the button and check if all the status lights are on.
Check if the Service Status or Broadband light is solid green. If so, the reset has succeeded,
Configure the router and check if the AT&T Internet is working. In the case of a Wi-Fi router, keep in mind it will revert to the default SSID and password (written on the router).
If that did not work, unplug the router’s power cable for 30 seconds and then plug back the cable into the router.
Hold the router’s reset button for 90 seconds.
Release the reset button and wait till the reset operation completes.
Once done, configure the router as per ATT instructions and check if the Internet is working.

13. Reset the Device to Factory Defaults

If a single device (such as your phone) is not able to use AT&T Internet, then that could be caused by the invalid OS modules. Here, resetting that device to the factory defaults will solve the problem.

Before resetting, make sure the ATT network is working fine on other devices and the internet issue is limited to your device only.

Note: Factory resetting the device will erase all data on it. Make sure to have it backed up and have your credentials at hand.