How to use High-Speed Internet Gateway with Existing Router

Without and Bridge Mode the T-Mobile product is useless for this kind of setup. Sadly it's already available in the hardware from Nokia but T-Mobile has removed it in their firmware. I will soon have to cancel my T-Mobile home internet service if they don't resolve this because it kills my VPN access to work. Since covid has pushed a lot of use to work remotely this is a critical need which T-Mobile has totally dropped the ball on.

I found that if I simply connected the router's Internet port to one of the lan ethernet ports, everything works. That was much easier than I was expecting.

What about creating a double NAT which will negatively impact gaming? Is this a problem? What games do you play and what kind of connection do you get? I'm interested in this, but if gaming doesn't work, it's a deal breaker.

Eric Terrell wrote:

I just got a T-Mobile High-Speed Internet Gateway and am trying out the ISP service. So far I'm very impressed with it.

I have the cylindrical device (5G21-12W-A).

I've read that it's possible to use this device with an existing router. Can anyone point me to instructions for doing so?

I want to do this as my router (NETGEAR Nighthawk Pro Gaming XR500 Wi-Fi Router) allows me to use an external USB hard drive as a NAS, which is very convenient.

If you're netgear has AP mode put it in that mode it will prevent double nat since the T-Mobile Gateway will provide the  local ip addresses then turn off the wifi on the T-Mobile highspeed gateway so you don't have interference from the T-Mobile wifi with the highspeed gateway you have to disable all ssid's in order to completely turn off the T-Mobile wifi. I have a netgear nighthawk router too that I use with my service and no double nat problems! Hope this helps!

You could disable NAT in the Netgear if double NAT is an issue for you.  For most things though, it won't make a difference. As mentioned, the easiest to ensure everything works easily is to just set the Netgear in AP Mode.  The modem doesn't have a Bridge Mode option and most that complain about that here seem hesitant and don't understand that disabling just a few settings within the modem will essentially achieve the same thing as Bridge Mode.  

Sadly, putting your original router into AP or bridge mode doesn't solve the problem very well, since most people have lots of networked gear already installed and configured - TV's, thermostats, cameras, Alexa's, lightbulbs and hubs, gaming consoles, etc etc.  Requiring all of those to be reconfigured to use TMobile as the authorative source for IP addresses and firewall rules (much of which cannot be adjusted using their simplified version of the controls) just isn't workable. To say nothing of range-extenders or meshed APs - all of which are common for the kind of customers who need 5G internet connection.
T-Mobile needs to keep iterating on the firmware here until they get this right for all their customers. Fingers crossed.

I am not a gamer, nor a networking expert so my answers will not completely satisfy you.

For what it’s worth, I did two ookla speed tests:

1. Hitting the Netgear router, which must have incurred the double NAT penalty
2. Hitting the T-Mobile device, which must not have incurred the penalty

The results (ping time, download and upload bandwidth) were almost identical.

@shaneg79@syaoran If I put my Netgear Nighthawk router in AP mode, will I still be able to have it host USB drives accessible in Windows?

I also have a network printer connected to one of the Netgear's ethernet ports, and have assigned a static IP address in the router config. Will that continue to work in AP mode?

¡Gracias!

Turning on Access Point Mode for some routers will disable the ability to login and manage the router until you factory reset.  I can't say for sure if that will happen with your Netgear.  The only two Netgear routers I ever owned, I returned promptly seeing how buggy the firmware was on both the AX80 and AX120.  Depending on your printer, it might not need a static IP.  My Brother MFC-9330CDW does not.  If you enable AP Mode on the Netgear and you can't access the Admin Web Interface for the router.  Hard reset it.  You can technically turn off some of the routing functions while still maintaining the web interface for the router by turning off DHCP, NAT, and a few other settings manually.  

Eric Terrell wrote:

@shaneg79@syaoranIf I put my Netgear Nighthawk router in AP mode, will I still be able to have it host USB drives accessible in Windows?

I also have a network printer connected to one of the Netgear's ethernet ports, and have assigned a static IP address in the router config. Will that continue to work in AP mode?

¡Gracias!

If you put it in AP mode you can still use the usb ready share on the nighthawk router if that's what you're asking. That option is not disabled in AP mode, I know because I have a 2 TB seagate drive that I connected to mine. Not sure about the static Ip addresses since the T-Mobile router would be the one handing out the ip addresses probably won't work just have to try it. Also I have no issues logging into the router like the above person stated you just need the ip addresses that the T-Mobile Gateway gives to your netgear router and then it will prompt for username and password. Not sure why the other person was having issues logging into theirs.