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Re: T-Mobile NOK 5G21 Gateway and Netgear R8000P - Now DNS Problems

ServiceGear
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T-Mobile NOK 5G21 Gateway and Netgear R8000P - Now DNS Problems

I was successfully using my Netgear Nighthawk R8000P router to connect to the internet through my Spectrum cable modem for a couple years. When I saw T-Mobile had a cheaper internet service than Spectrum, I decided to try it out. I got the T-Mobile NOK 5G21 gateway and connected it via an ethernet cable to my Netgear router (after disconnecting the Spectrum cable modem, of course). So now, I basically had  two wifi networks in my house, the T-Mobile network and the Netgear network. Then, I noticed that there were some web sites I tried to access via the Netgear wifi (in my Chrome browser) that were giving me what looked like some sort of DNS errors, like, "This site can't be reached" with DNS_PROBE_FINISHED_NXDOMAIN. Sometimes, the error would appear and then, after a few seconds, the web site/web page would successfully display. Other times, it would just fail. The problems are intermittent but happen about 90% of the time for a small set (so far) of web sites. I tried deleting all the browser cache. I disconnected and turned off the T-Mobile gateway. I did a factory reset on the Netgear router and reconfigured it. I had Spetrum support "reprovision" the cable modem. The problem persists. It's MADDENING! Note that this problem does not occur on my IPad or my Android phone going through the same network. Also, the T-Mobile gateway as no trouble getting to any of these web sites. What the heck is going on here? What went wrong?

Message 1 of 8

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ServiceGear
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Re: T-Mobile NOK 5G21 Gateway and Netgear R8000P - Now DNS Problems

Summary: I was having trouble getting to some subset of internet sites. I was getting what looked like DNS errors of some sort. I THOUGHT that this problem started happening when I started switching from my Spectrum internet service to T-Mobile's internet service. I THOUGHT things started going bad when I connected my T-Mobile NOK 5G21 gateway to my Netgear R8000P router. What I forgot about was, not too long ago, I DID upgrade my Netgear router to the most recent firmware version (V1.4.2.84_1.3.42).  

 

In plemans' reponse to my posts, he suggested that the most recent version of the Netgear firmware might be having (or causing) some trouble with DNS resolution. Plemans suggested I update the Netgear firmware to an older version. So I downloaded firmware version V1.4.1.68_1.3.28. This was the firmware version immediately prior to the recent firmware upgrade. Much to my surprise and delight, this seems to have fixed this problem. 

 

I am still working through some of the options plemans suggested regarding how to connect the T-Mobile gateway to the Netgear router. So far, the T-Mobile gateway configuration screens do not support bridge mode, a DMZ (at least, as far as I can tell). I am not sure I want to put the Netgear router into AP mode (I will lose too much functionality). I have connected (via ethernet cable) the T-Mobile gateway to the Netgear router and it all seems to be working OK. But I am almost certainly getting double NAT in this configuration (again, as plemans suggested). 

 

Bottom Line: The main problem with the DNS resolution I think as been solved.

 

MANY THANKS to plemans for providing what looks like the solution to my problem.

 

View solution in original post

Model: R8000P|Nighthawk X6S AC4000 Tri Band WiFi Router
Message 7 of 8

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Re: T-Mobile NOK 5G21 Gateway and Netgear R8000P - Now DNS Problems


@ServiceGear wrote:

I was successfully using my Netgear Nighthawk R8000P router to connect to the internet through my Spectrum cable modem for a couple years.

 


What firmware version do you have on the device?

A number is more useful than "the latest". (It may not be by the time people read this.) There can also be newer versions, or "hot fixes", that do not show up if you check for new firmware in the browser interface.

 

Just another user.

My network DM200 -> R7800 -> GS316 -> PL1000 -> Orbi RBR40 -> Orbi RBS50Y -> RBS40V
Message 2 of 8
ServiceGear
Guide

Re: T-Mobile NOK 5G21 Gateway and Netgear R8000P - Now DNS Problems

Firmware Version: V1.4.2.84_1.3.42

Model: R8000P|Nighthawk X6S AC4000 Tri Band WiFi Router
Message 3 of 8
plemans
Guru

Re: T-Mobile NOK 5G21 Gateway and Netgear R8000P - Now DNS Problems

2 things you can try if you're staying on the spectrum modem. 

1. enable ipv6. then reboot the router/devices

2. downgrade the firmware a version. I've seen dns issues on the firmware version .

 

 

if you stay with tmobile, you can try the same but also it causes a double nat with the 2 routers. 

A double nat happens when you cascade more than 1 router.
https://kb.netgear.com/30186/What-is-Double-NAT
Fixes? There’s 3 options but only use 1.
1. Put the modem/gateway in modem only/pass through mode. This disables its routing functions.
2. Leave the modem/gateway in router mode but put the Netgears IP address into its DMZ. This forwards the data to the netgear. You can either leave the modem/gateway’s wireless enabled or disabled. Just make sure its using a different wifi channel to prevent interference
3. Put the Netgear into access point mode. This disables its routing functions. Wifi/ethernet still works but it does disable some features.
https://kb.netgear.com/26765/Which-features-are-disabled-on-my-NETGEAR-router-when-it-is-set-to-AP-M...

Current setup: CM2000-> RBKE963B-> Trendnet TEG-S380-> GS716T-> pi-hole
also in AP setup: RAXE500->EAX80
1.4gig download/50mbps upload from Xfinity
We’re members of the public helping out on our own time.
Message 4 of 8
ServiceGear
Guide

Re: T-Mobile NOK 5G21 Gateway and Netgear R8000P - Now DNS Problems

Questions:

1. How do I downgrade the router firmware?

2. You say that if I choose to stay with T-Mobile, I can try to "Put the modem/gateway in modem only/pass through mode". Are you saying to put the T-Mobile gateway into modem only/pass through mode? If so, I can try that, but the T-Mobile gateway has a limited number of options and controls. I haven't come across anything in its configuration screens (yet) that allows for that choice or option. I may have to reach out to T-Mobile tech support if I choose to go that way. 

Message 5 of 8
plemans
Guru

Re: T-Mobile NOK 5G21 Gateway and Netgear R8000P - Now DNS Problems


@ServiceGear wrote:

Questions:

1. How do I downgrade the router firmware?----you download the firmware from the support site (downloads---->+view previous versions). Then follow the manual update process but use the older firmware. Pretty easy to do. 

2. You say that if I choose to stay with T-Mobile, I can try to "Put the modem/gateway in modem only/pass through mode". Are you saying to put the T-Mobile gateway into modem only/pass through mode? If so, I can try that, but the T-Mobile gateway has a limited number of options and controls. I haven't come across anything in its configuration screens (yet) that allows for that choice or option. I may have to reach out to T-Mobile tech support if I choose to go that way. -----I just mean you'd need to use 1 of those 3 options to fix the double nat. You just have to use what works for your setup. 


 

Current setup: CM2000-> RBKE963B-> Trendnet TEG-S380-> GS716T-> pi-hole
also in AP setup: RAXE500->EAX80
1.4gig download/50mbps upload from Xfinity
We’re members of the public helping out on our own time.
Message 6 of 8
ServiceGear
Guide

Re: T-Mobile NOK 5G21 Gateway and Netgear R8000P - Now DNS Problems

Summary: I was having trouble getting to some subset of internet sites. I was getting what looked like DNS errors of some sort. I THOUGHT that this problem started happening when I started switching from my Spectrum internet service to T-Mobile's internet service. I THOUGHT things started going bad when I connected my T-Mobile NOK 5G21 gateway to my Netgear R8000P router. What I forgot about was, not too long ago, I DID upgrade my Netgear router to the most recent firmware version (V1.4.2.84_1.3.42).  

 

In plemans' reponse to my posts, he suggested that the most recent version of the Netgear firmware might be having (or causing) some trouble with DNS resolution. Plemans suggested I update the Netgear firmware to an older version. So I downloaded firmware version V1.4.1.68_1.3.28. This was the firmware version immediately prior to the recent firmware upgrade. Much to my surprise and delight, this seems to have fixed this problem. 

 

I am still working through some of the options plemans suggested regarding how to connect the T-Mobile gateway to the Netgear router. So far, the T-Mobile gateway configuration screens do not support bridge mode, a DMZ (at least, as far as I can tell). I am not sure I want to put the Netgear router into AP mode (I will lose too much functionality). I have connected (via ethernet cable) the T-Mobile gateway to the Netgear router and it all seems to be working OK. But I am almost certainly getting double NAT in this configuration (again, as plemans suggested). 

 

Bottom Line: The main problem with the DNS resolution I think as been solved.

 

MANY THANKS to plemans for providing what looks like the solution to my problem.

 

Model: R8000P|Nighthawk X6S AC4000 Tri Band WiFi Router
Message 7 of 8
plemans
Guru

Re: T-Mobile NOK 5G21 Gateway and Netgear R8000P - Now DNS Problems

glad you got the biggest part of it fixed!

Current setup: CM2000-> RBKE963B-> Trendnet TEG-S380-> GS716T-> pi-hole
also in AP setup: RAXE500->EAX80
1.4gig download/50mbps upload from Xfinity
We’re members of the public helping out on our own time.
Message 8 of 8
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