How to block Ultrasurf and Tor application (on win 10) - new user

[moshe]

Hi,
i have used k9 for years but seem that it can be break using ultrasurf and tor.
i have install nxfilter and i am completely new to this app - can someone please guide me how to block those applications? ?
any help will be appreciated,
thank you,
Moshe

[support200]

We only can block something on DNS level. We can't block them.

If you want to block UltraSurf, you need to lock webproxy settings as it's a webproxy. Our users do that using GPO of Active Directory mostly.

For Tor, it's more difficult as it has its own browser. You have to find some kind of application control program if there's any. However, using Tor is not that easy as it's slow and many websites block Tor users.

[moshe]

thank you for the answer.
i will appreciate the answer to the following question:
1. is nxfilter better vs K9 (blue coat)
2. when i block "porn" category. if i search on google for porn images - will i get results? and if so will they be bluer or clear to see?
thank you

[support200]

K9 is a personal software. I guess you are using it for your kids.

NxFilter is a network wide filtering server. You can use it for whole family.

There's an option for safe search on a policy. You can force safe search for users. You can block Porn category and force safe search for your kids and then you even block some search keywords if they use Chrome or Edge using CxBlock. https://tutorial.nxfilter.org/d-cxbl...ltering.php#ur

NxFilter supports user authentication using IP association and login page. It means that you can have multiple policies in your network based on usernames. You can force safe search to your kids but not for yourself.

It's not basically for family protection. There are schools using it for their students and staffs with multiple policies. You can see the usage reports here from some of them, https://forum.nxfilter.org/usage-reports

The schools are the members of our test user group. Some of them have several thousand users. And there are many companies using NxFilter in their offices. And we have some telecom companies as our customers. One of them service NxFilter to their mobile users and the number of users is bigger than 75000 at the moment.

Maye you can compare NxFilter to Blue Coat WebFilter but not to K9.

Read our tutorials. You can find what it is. https://tutorial.nxfilter.org/index.php

[moshe]

thank you so much for your answer 🙏.
your right - i use it for my kids, and i don't even want that by mistake some not appropriate image will jump to the screen while they surfing
a. i don't know the difference between Blue Coat and K9 (i know that K9 is from Blue Coat , and also i think the support for K9 came to its end).
b. can i use both k9 and Nxfilter? - or its no need? (i mean - or they cant work together or Nxfilter, makes better job regards filtering not appropriate content)
c. i will read more about this and hopefully ask more in this thread
enjoy your week,
Moshe

[support200]

You can use both of them. I guess K9 is a webproxy. It only works for websites but NxFitler works on DNS level. It deals with other protocols as well as long as they use DNS. Or I can put it in this way. K9 blocks something on browser only but NxFilter can block other software as well.

K9 is a personal software installed on each PC. And Blue Coat WebFilter is a webproxy for whole network. It's a bit of an old fashioned way and may slow down your network as it requires all the HTTP/HTTPS traffic going through the WebFilter. NxFilter is kinda lightweight as it uses DNS protocol. However, these latency problem is only meaningful when you deal with at least several hundred users.

[moshe]

Hi,
i have followed the YouTube torurial for installation.
when i enter on powershell the following comand,i get this error:

PS C:\Users\my_user> gc c:\nxfilter\log\nxfilter.log -tail 10 -wait
INFO [08-17 10:29:21] - RMcR, Adding a upstream resolver : SimpleResolver [/8.8.8.8:53].
INFO [08-17 10:29:21] - RMcR, Adding a upstream resolver : SimpleResolver [/8.8.4.4:53].
INFO [08-17 10:29:21] - RMcR, Resolving DNS server : [8.8.8.8, 8.8.4.4]
INFO [08-17 10:29:21] - RMcR, Adding a upstream resolver : SimpleResolver [/8.8.8.8:53].
INFO [08-17 10:29:21] - RMcR, Adding a upstream resolver : SimpleResolver [/8.8.4.4:53].
INFO [08-17 10:29:21] - MM, RequestHandler started.
INFO [08-17 10:29:21] - MM, UdpServer started.
ERROR [08-17 10:29:21] - UdpServer.run, java.net.BindException: Address already in use: Cannot bind
INFO [08-17 10:29:21] - UdpServer.run, Couldn't bind UDP/53. You might want to check your permission!
INFO [08-17 10:29:21] - ShutdownHook.run, Shutting down on 2022-08-17 10:29:21..

is it because i have already k9 installed?
do you know how to solve it?
thank you,
Moshe

[support200]

Something is using UDP/53. DNS servers are using it. Whatever it is, you need to uninstall it. You can find which software it is by TCPView I guess. In my memory, you can detect UDP with it even though its name is TCPView.

And why do you need to install K9 in the system? You need to run NxFilter on a separated system which can be running as a server. Mostly 24 hours of running. If you have a redundant system, install NxFilter there.

[moshe]

Hi,
a. is TCPView is an application already on win10? or should i download it?
b. I have k9 already installed on this computer, and i understand that i can "combine" and use both applications
thank you

[support200]

You have to download it. Try to Google it.

Yeah, you can combine it but why do you need to install NxFilter on a client PC? It's a server software. Not a personal software.

[moshe]

i just have read on the web that its a good web filter...and it can block ultrasurf and tor.
i dont understand the difference between server and personal computer

[support200]

Yeah, that's a bit to difficult to explain. Just think of it NxFilter like programs are used for filtering thousand of PCs at the same time by one installation. But you install K9 into each PC. And that's why we use NxFilter like program in schools or offices. We want to filter and monitor PCs and mobile devices centrally.