Follow Up: How to use the XR500 as a second router? How do I avoid double NAT?

Hi all,

I recently posted about a Double NAT issue I was facing with the Netgear Nighthawk XR500 and the Xbox One X here 👉 https://community.netgear.com/t5/Nighthawk-Pro-Gaming-Routers/How-to-use-the-XR500-as-a-second-router-How-do-I-avoid-double/m-p/1773111

This is a follow up to that...

A little bit background:

My ISP has installed a modem/router (D-Link DIR-825) on the ground floor of my house where the internet is set up. I recently purchased a Netgear Nighthawk XR500 Pro Gaming Router and set it up upstairs and connected it via ethernet cable to the modem downstairs. Everything works fine, except I get Double NAT issues on Xbox and I'm sure this also effects the performance of other devices.

After doing some research, I was able to find out that I need to put my first modem/router into "Bridge Mode". However, the first modem/router does not support "Bridge Mode". I've heard of solutions related to DMZ, Port Forwarding, and disabling DHCP servers as well.

What I tried:

As suggested by Netduma_Alex, I found out my XR500 router's WAN IP and placed the IP in the DMZ settings in the Modem/Router Upstream. This fixed the problem temporarily and my NAT status was OPEN. A few hours later, I checked the Network settings on Xbox and it was back to "Double NAT". I checked the DMZ settings again and everything was fine. I even ensured that the router has a fixed/reserved IP which it does.

What can I do?

Am I doing something wrong? Do I need to disable DHCP for the first modem/router even though my DMZ settings are correct? I'm really running out of options here and I'm willing to buy a new modem/router as the first modem/router.

Next Steps:

If there is nothing else I can do, I do not mind purchasing another modem/router to function simply as a bridge. If I am purchasing a new modem/router to function as a bridge, which Netgear model do you suggest will work best with the XR500? Also which Netgear Modem/Routers support Bridge mode?

In India, these are some of the models available:

1. Netgear R6400-100INS AC1750 Dual Band Smart Wi-Fi Router
2. Netgear R6260 AC1600 Smart WiFi Router (Black)
3. Netgear R6120-100INS AC1200 Dual-Band Wi-Fi Router

There are more models available but these are what I found first on amazon. Which do you suggest I purchase? And do all of these support Bridge Mode?

Please help

Netduma_Alex bacevedo