I have an ATT netgear nighthawk WiFi box. Xbox is wired to it. Can’t get rid of double nat....

Hello Cowboyfresh,my name is Marvina, I will be happy to help you with your problem.

I am very sorry for what you are going through, that kind of problem can be very annoying since Double NAT is a problem that occurs when two or more network devices perform the routing function. This can cause connectivity and performance issues, especially for online gaming.

As a possible solution to your problem it would be:
Log in to the router's web-based configuration page and make sure UPnP is enabled. ...

Disable UPnP and save the changes.
Restart the console after a complete shutdown and restart all network hardware (modem and router).

Source: https://support.xbox.com/help/hardware-network/connect-network/xbox-one-nat-error

These are basic solutions to these problems, but they can lead to a solution, remember that this is a public forum where we are players like you who want to help, good luck and happy day.

Sincerely,
Marvina.

Hardwired the Xbox directly to the ATT "gateway" and it still shows strict NAT. I got the ports forwarded through my Orbi's setup and my xbox shows "Open nat" until i perform a nat test and it goes straight back to strict/double NAT. I have tried to go
through the ATT's gaming/nat setup and forwarded the same ports as well with the same result. After resetting the Xbox it goes to open but if i perform any tests especially nat test... right back to strict/double. This happens both wireless and wired to
either the Orbi, or the ATT paperweight =-(

To clarify a little on the gateway side as well... As far as i can tell its is bridged but then this ATT has so many settings inside of it who knows. I have shut down the ATT box's wifi bands totally and did the " IP Passthrough" in order to use my Orbi
system as the primary routing setup for the house.

Check out Netgear R7000 Nighthawk, their ads said "it's optimized for Xbox one / 360". I got one, an have no problem with NAT being open, on the Xboxes. Great WiFi range, an dual band, and QoS support.

Hardwired the Xbox directly to the ATT "gateway" and it still shows strict NAT. I got the ports forwarded through my Orbi's setup and my xbox shows "Open nat" until i perform a nat test and it goes straight back to strict/double NAT. I have tried to go
through the ATT's gaming/nat setup and forwarded the same ports as well with the same result. After resetting the Xbox it goes to open but if i perform any tests especially nat test... right back to strict/double. This happens both wireless and wired to
either the Orbi, or the ATT paperweight =-(

To clarify a little on the gateway side as well... As far as i can tell its is bridged but then this ATT has so many settings inside of it who knows. I have shut down the ATT box's wifi bands totally and did the " IP Passthrough" in order to use my Orbi
system as the primary routing setup for the house.

Could you connect your PC/Mac directly to your AT&T and find out what IP your client get assigned.

On a Windows machine: Bring up the command prompt (cmd) and type "ipconfig" (without quotes).

On a Mac: Bring up terminal window and type "ifconfig" (...).

Post up the first two octets of your IPv4 address. For example, 192.168.xxx.xxx. Remember, only the first two octets.

Party chat is also not functional for me. I am behind an Open NAT through one of the new Netgear Nighthawk routers on a wired connection. I suspect this is an issue with something on Microsoft's end.