Not getting response from NxFilter DNS server

[RothKevin]

Hello,

First of all, I want to say thank you for this amazing piece of software. I stumbled across it while googling around for DNS filtering options and have been messing with it for the past 4 hours!

I will try to explain my scenario as best possible - please be patient with me as I am not super savvy with DNS.

Currently I am having trouble getting a reply using 192.168.0.203 as DNS server (NxFilter):


Let me explain how I have setup Nxfilter:

1. Downloaded and installed NxFilter exe on Windows 11 machine
2. This machine currently has the IP of 192.168.0.203 and is acting as the "server" for nxfilter
3. Went through the initial nxfilter configuration / setup for DNS / users / filtering / enabled authentication:

I can access Nxfilter from host machine via loopback or via http://192.168.0.203/admin.jsp

1. Filtering ONLY WORKS through Nxproxy and Cxblock (chrome extension).
2. When attempting to setup DNS servers manually to 192.168.0.203 on either host machine or client machine I do not get a DNS reponse. Basically, there is DNS failure.
3. I can ping 192.168.0.203

I guess I am trying to understand this a little better please:

• Is it possible for 192.168.0.203 to be both the IP for my host machine and for Nxfilter DNS servers?
• Is there a reason why filtering only works through proxy / cxblock but will not work locally?
• Have I gone wrong anywhere in the setup here?

I am wondering if there are ports I need to open on the host machine's windows firewall?

Thank you in advance for the reponse!

[support200]

When we do development work for NxFilter. We also install it on our own system locally and set it to be the DNS server for our system. So, it should be working. But we don't recommend it in a production environment as NxFilter make some DNS queries while its startup time.

Can you use it as a DNS server through UDP/53 from other PCs then?

[RothKevin]

Currently, I have it installed on my local system to be DNS server but all queries are failing. This is a home network / non-production environment. I am unable to set it up on other PCs statically either.

[support200]

What I am saying is that you can do 'nslookup google.com 192.168.0.203' from another PC and see what happens. If you don't have one more PC, you can do it from your smartphone as there's nslookup or dig like utility for Andoroid/iOS.

[RothKevin]

I have another laptop here with me and get same result when doing Nslookup from it; it times out. But filtering does work through cxblock and Nxproxy on the laptop.

[support200]

Sorry, did you install NxProxy on the same PC as your NxFilter? Then your NxProxy is hijacking UDP/53 traffic to itself. So, your NxFilter can get any traffic through UDP/53/

NxProxy is basically for remote filtering. We recommend you to have a separated system for running NxFilter.

Do you use it for your home network? But you don't want to have another system running NxFilter? That's what you want? Maybe you can install it on Google Cloud. They offer some free credits for running a VM. you can install NxFilter there and you can install NxProxy on your PCs. Then you get your filtering wherever you go with your laptop.

[RothKevin]

Thanks for your reply.

Actually the host machine where nxfilter is installed only has nxfilter running. When I tried to install nxproxy on there it would have issues starting the service. I imagine the port conflict you mentioned. However, on my laptop or secondary client only nxproxy is installed and works fine.

I do not want to accomplish anything in particular other than setup nxfilter in my home network to block adult content and enable safe search. I thought setting the default dns servers on the NICs to 192.168.0.203 might do the trick but no luck.

After playing around for a bit I noticed something: when I run nslookup and specify the port I do get a reply both from host (nxfilter) and laptop (nxproxy client)
nslookup google.com 192.168.0.203:53



The laptop also gives a similar reply but with an address of 127.0.0.1 (loopback)

I'm also noticing that whenever I statically assign an IP to any computer I do not get connectivity. I have DHCP running off of my ISP provided modem/router. So I am guessing it might be a problem with that device since I am not able to assign static IP either?

What do you think?

[support200]

When you specify 53, it's about Invalid IP Address and its uses a default DNS server from your system settings.

Try this on your NxFilter system,

nslookup block.nxfilter.org. 127.0.0.1

And then,

nslookup block.nxfilter.org. 192.168.0.203

If the first works and the second one not working, it may be a firewall issue. Did you install it using our EXE package?

[support200]

Sorry, you mentioned that you installed it using EXE. We add some firewall rules during the install process. Anyway, see if it works when you use 127.0.0.1.

[RothKevin]

Thanks for clariying.

So this is interesting. Running nslookup via 127.0.0.1 times out briefly and gives a reply, but running nslookup via 192.168.0.203 gives no reply whatsoever

..


And yes I installed with EXE package

[support200]

For testing purpose, can you disable your firewall on NxFilter system?

[RothKevin]

Definitely worth a try. Unfortunately same result 😣

[support200]

That's very weird. Can you show me the result of this command then?

ipconfig /all

[RothKevin]

Here it is!

[support200]

Can you make it a static IP address then? You can change its IP as well to exclude the situation that you have a system having the same IP in your network.

[RothKevin]

Are you asking me to change to an IP other than 192.168.0.203? Here are my current settings:


When I try using 0.203 as DNS I don't have connectivity.