Did AT&T push a firmware update that wiped out subnets?

We're here to assist with your gateway subnets, @marc9889!

If you haven't already go ahead and perform a reboot of your equipment. Doing this can usually resolve a host of concerns, such as the one you are experiencing.

Here are the steps to take:

1. Unplug the power cord from the back of your gateway or modem. If you have: 
   • An internal battery backup, remove it
   • DSL, unplug the phone cord from your modem or gateway
2. Wait 20 seconds.
3. Put the internal battery back in if you have one. 
4. Plug the power cord back in. If you have DSL service, reconnect the phone cord.
5. Wait for the gateway or modem to restart and your Broadband light to turn solid green. This can take up to 10 minutes.

If that doesn't work, go ahead and perform a factory reset of your gateway. This will clear any settings that could be causing the error to occur.

You can perform this with these steps:

1. Press and hold the gateway Reset button for at least 10 seconds. If you let go before 10 seconds, the gateway will reboot, but it won’t reset.
2. Wait until the gateway restarts and all the status lights are lit. 
3. See if the Broadband or Service status lights are solid green. If so, the reset worked.

Heads up: Be sure to jot down your custom settings, like your static IP address if you have one, or your Wi-Fi^® network name (SSID). You can then change them back after the factory reset.

let us know if this resolves your cocnern! If not, we can perofmr some more troubleshooting to see what is the root cause of this.

CalebP, AT&T Community Specialist 

Let me try again. 

I have an Arris gateway. After it was installed, I set up a subnet, and had several devices connected to that subnet. Those devices stopped working. Looking at the configuration of the Arris now, there are no subnets. To restate the question, did AT&T push a firmware update that would have removed existing subnets on my Arris gateway? 

Hi there, marc9889. We understand that your networking subnets are missing from the router. Let's look at that together. 

There was an update that was done to improve the Wi-Fi of the router a few weeks ago. However, this update was to improve the Wi-Fi functionality of the router. 

Since subnetting is a customized setting, unless the router itself was factory reset somehow, your subnets should be still there. 

Have you attempted to re-enter in your customized configuration again? If not, please attempt to do so and let us know if your subnets are back up and working again. 

Matthew, AT&T Community Specialist