r6400

[RobertSearl]

I installed the latest update: Firmware Version V1.0.1.72_1.0.45

Now I get messages like:

"This site can’t be reached

Check if there is a typo in login.gmx.com.

• If spelling is correct, try running Windows Network Diagnostics.

DNS_PROBE_FINISHED_NXDOMAIN"

....or something similar on several of my sites. I can find no problems with diagnostics and am current on all systems, Windows, Chrome etc. All ad blockers, etc. are turned off. The ONLY change to my system has been the Netgear update.

How do I "uninstall" the update?

[plemans]

What gateway/modem are you connected to? 

did you try a factory reset after the update? I'd try this before downgrading

Did you try a different dns server? like googles at 8.8.8.8 or 8.8.4.4  or even cloudfare at 1.1.1.1

[vjayer]

I have this exact same problem too, and it only seems to affect Windows machines.

It appeared before the current firmware, maybe about 2 firmware versions ago, although they have been released close together.

Basically, if I use the router's DHCP setting and not modify it per client, therefore accept it as the DNS resolver, Windows machines frequently have DNS timeouts/resolution problems.

Just retrying several times will eventually overcome the DNS issue, but it's frequent and annoying and will interfere with anything automated or queued

Interestingly Linux clients do not have this problem even when using the R6400 router for DNS resolution.

[vjayer]

just to update, I have a few times gotten dns issues on linux and Android devices since the recent firmware releases. But very rarely in comparison to Windows.

With the router acting as the dns server, I assume is just forwarding all the requests to my ISP (whose dns servers are listed in the Advanced > Internet Port section)

I don't know much about this, but is the router caching (the TTL in DNS) and is there an issue with this?

[atekkof]

Hello, I am writing to confirm that I am also having the same issue. I spent an entire week troubleshooting my DNS before finding this thread. Definitely the Netgear firmware and I'm using the R6400. It typically takes half a year between firmware versions, so I really hope someone in their dev department in paying attention.

Setting the DNS locally on the devices should help in the short term, but I have a lot of devices and I want them all to use the same DNS servers, so this is super annoying.

And yes, I second that it only seems to be Windows devices at this point.

[RobertSearl]

I did a reset, no joy.

[RobertSearl]

I am having the problem as you state. Probem is; I have no idea about DHCP or DNS settings. I have NEVER had a router problem until this last Netgear "update". If I could go back in time, I would.

Thanks for your help!

[plemans]

---

@RobertSearl wrote:

. If I could go back in time, I would.

---

You can downgrade. Simply go to the support site for your device, click on downloads, and then "view previous versions". 

Once downloaded, extract it, and follow the manual firmware update process but use the downgraded version of the firmware and not newer. 

Anytime you downgrade, I'd recommend doing it over a hardwired connection. 

[RobertSearl]

I could not find "view previous versions" for the R6400.

[plemans]

Just looked it up. 

you clicked on downloaded? 

then scroll down to the bottom. 

you'll see "+view previous versions"

I'd screen shot it for you but not on a device to do so right now

[Schneckre]

I have the same problem, but mine began after pressing a blue update button in the Night Hawk App. it updated to version: V1.0.1.74_1.0.48

It's driving us crazy. Need a fix. Trying to work form home.

[plemans]

@Schneckre did you try the downgrade as recommended?

If so and you're still having issues, start your own thread so we can individualize the help and not confuse your info with the OP's. 

[Schneckre]

Nervous about attempting dowgrade (Wife and Daughter work from home). I haven't found detailed instructions for this process. I have downloaded V1.0.1.72. Tried to print page 133 from the manual, I now get a printer connection error. It's a mess.

[plemans]

Downgrading is pretty easy. download the firmware version you want, extract it.

then follow the manual firmware update process but use the older firmware. 

I usually advise people to do a factory reset afterwards but you can try it without. 

I would advise using a hardwired connection (ethernet) for best results. 

https://kb.netgear.com/23960/How-do-I-manually-update-the-firmware-on-my-NETGEAR-router

[vjayer]

I think I found the solution:

Windows by default now prioritizes / prefers ipv6 name resolution
i.e. nslookup <hostname>
shows ipv6 addresses first, then ipv4

To change setting to allow this default Windows 10+ configuration,
in the netgear R6400 gui:

Advanced > Advanced Setup > IPv6
	Internet Connection Type: [Auto Detect] > Apply
- after a short time, resulted in [DHCP] for me with:
	Router's IPv6 Address On WAN: <... ipv6 address from your ISP ...>
	IPv6 Domain Name Server (DNS) Address > Get Automatically from ISP
	IP Address Assignment > Auto Config

So far I've had good luck by enabling ipv6 on the router. All proper DNS lookups resolve on the first try