Britgirl

[Britgirl]

Hi,

what version of Fail2Ban are you using? We have an article that outlines how to configure Fail2Ban with NoMachine which you can consult here: https://kb.nomachine.com/AR05P00983. These changes apply to the latest version of NoMachine, currently 8.9.

We just updated it to include the change required for Fail2Ban 1.0.2 or later, which are reported below.

For Fail2Ban v1.0.2 and later, the following changes need to be made:

———-
sudo cat /usr/NX/share/fail2ban/nxauth.conf
———-
#
# Fail2Ban filter for NoMachine.
#

[Definition]

#
# The default regex matches all the supported authentication methods
# for connections by NX protocol, which are:
# password   : Password authentication.
# private-key: Key-based authentication.
# kerberos   : Kerberos ticket-based authentication.
#
# For example, set the regex to match password based authentication
# method:
#
# method=password
#
# Most common error messages:
#
# Method: password
# ErrorMsg: Wrong password or login
#
# Method: private-key
# ErrorMsg: Public key not recognized
# ErrorMsg: Wrong signature
#
# Method: kerberos
# ErrorMsg: Kerberos GSS token is not verified
# ErrorMsg: Kerberos GSS user is not valid
# ErrorMsg: Kerberos GSS MIC is not verified
#

method=[^’]*
errorMsg=[^’]*

failregex = ^.*ERROR! Authentication with ‘.*%(method)s.*’ from host ‘<HOST>’ failed\. Error is ‘%(errorMsg)s’\.$

ignoreregex =

datepattern = %%Y-%%m-%%d %%H:%%M:%%S

———–
sudo cat /usr/NX/share/fail2ban/nxd.conf
———–
#
# Fail2Ban filter for NoMachine.
#

[Definition]

#
# Regex matches all accepted NX protocol connections.
#

failregex = ^Info: Connection from <HOST> port \d+ accepted on.*$

ignoreregex =

datepattern = %%a %%b %%d %%H:%%M:%%S %%Y

[Britgirl]

Hi,

what version of Ubuntu is it?

When you try to connect to the Ubuntu machine, what OS are you connecting from?

Are you able to connect from the Ubuntu machine to any of the other computers on LAN?

Do you get the same error if you start a session manually by clicking ‘Add’ and inserting the IP address in the host field, or by inserting the IP address in the ”Search” field, and clicking ‘Connect’?

If you right click the Ubuntu machine icon in Machines (it’s the icon with a pipe symbol), and select ‘Edit connection’, what do you see (attach screenshot please)?

related to https://forum.nomachine.com/topic/connection-time-out-trying-to-access-nomachine-ubuntu-desktop where you can find a workaround.

[Britgirl]

Nuertey, your file shows

Oct 12 16:42:15 ip-10-102-91-113.xxxxxx.com gnome-session[3258]: gnome-session-binary[3258]: WARNING: software acceleration check failed: Child process exited with code 1

You can try adding --disable-acceleration-check option in the gnome-session command in the DefaultDesktopCommand key, in /usr/NX/etc/node.cfg.

[Britgirl]

So now you can connect with NoMachine?

[Britgirl]

This message appears when NoMachine finds no display running, so it asks you if you want to create one.  NoMachine is designed to work out-of-the-box on Linux headless machines provided a desktop environment is installed. NoMachine is able to detect when the X server is not running and run its own virtual display, which is an embedded X server.

If you click “yes” what happens?

[Britgirl]

Hi, can we see server logs, journalctl output, and additionally xrandr output before and after the NoMachine connection?

To get NoMachine server logs, please follow the instructions here and send to forum[at]nomachine[dot]com using “Cannot restore X11/KDE resolution after disconnecting” as the title.

https://kb.nomachine.com/DT07S00243

Thanks.

[Britgirl]

Hi Nuertey, send it to forum[at]nomachine[dot]com. There must be a character in the file that is clashing with our filter.

[Britgirl]

Thanks for your report. We will investigate what can be done from our side. Have you reached out to Wacom as well?

[Britgirl]

Hi, the logs didn’t attach, please send them direct  to forum[at]nomachine[dot]com. You can reply to our email which asked you to update to the most recent version of NoMachine 🙂

[Britgirl]

Could it be a networking issue on the client side? Are you still not able to connect from Monterey?

[Britgirl]

I am able to get a desktop connected with NoMachine if I use a barebones local user account. If I use my Active Directory login with sssd, it doesn’t work. So it could be something related to my AD user configuration, or something with sssd specifically.

This seems to be a different problem to the original one and we don’t understand how the two could be related without investigating further. This might warrant a separate topic so as not to confuse the thread. But first the original issue of not being able to create a display…

For some reason Gnome is failing and to understand why we would need to see the journalctl log of the server. Run (without the ‘grep’)

sudo journalctl -x

[Britgirl]

This is a for zany130. Version 8.9.1 should solve the problem for you.

[Britgirl]

Maybe you didn’t uninstall NoMachine as expected (as in the guide). You just removed /usr/NX directory which is not the correct way. If you do that our uninstall scripts can’t clean the system. Do the following:

1) sudo rm -rf /usr/NX /etc/NX /var/NX
2) install NoMachine by rpm -i nomachine….rpm
3) uninstall NoMachine by rpm -e nomachine…..

[Britgirl]

Hm, possibly a misconfiguration still? It you want video and audio, then WebRTC needs to be enabled.

[Britgirl]

We are not able to report your exact same error, but there is a similar issue which is reported here but related to the Moonlight theme: https://kb.nomachine.com/TR01U10758 which is linked in the topic from those listed above (https://forum.nomachine.com/topic/ubuntu-22-04-1-lts-authentication-failed-when-asked-for-admin-password).

What you could check is whether installing zenity helps, sudo apt install zenity. If that doesn’t help, update to NoMachine 8.9 and let us know if the problem persists.

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