Introduction

Welcome to the NoMachine Enterprise Terminal Server Node - Installation and Configuration Guide v. 9.

1. NoMachine Enterprise Terminal Server Node Installation and Configuration Guide

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What is NoMachine Enterprise Terminal Server Node for?
NoMachine Enterprise Terminal Server Node is designed to be specifically installed on a Linux remote node and be part of a multi-node environment ruled by a NoMachine Enterprise Terminal Server or a NoMachine Enterprise Terminal Server Cluster. For sake of simplicity, we will refer to 'Enterprise Terminal Server' in this guide.

NoMachine Enterprise Terminal Server Node is not a standalone server and cannot accept direct connections to its host!

A Graphical Interface
The NoMachine Enterprise Terminal Server Node server package includes a User Interface (UI) for administering the node and its services (Server settings).

Most common operations detailed in this guide can be performed by the NoMachine UI and the Server settings panel running on the local installation of the node.

More details about the Server UI can be found in the dedicated guide available in the Documents section at: https://www.nomachine.com/all-documents

The Enterprise Terminal Server Node comes also with a client UI for running sessions and connecting to other remote desktops. The same UI can be also used by administrators to administer another NoMachine server remotely. This remote administration UI mirrors the local NoMachine server UI and allows to perform the same operations.

The Enterprise Terminal Server Node is ready once installed
Installation provides a fully operative NoMachine node with a default configuration suitable for the majority of environments. All the necessary services are automatically started. Just add it to the Enterprise Terminal Server!

A node of the Enterprise Terminal Server
NoMachine Enterprise Terminal Server Node, available for Linux only, supports unlimited concurrent virtual desktops. A virtual desktop is a personal instance of the remote Linux desktop. The number of users is not limited. Users should connect to the IP or hostname of the Enterprise Terminal Server in order to reach the node.

1.1. About This Guide

Document Conventions and Important Notices
The following conventions are used in this Guide:

BaseDirectory
is the base directory where the NoMachine binaries and libraries are installed.
By default, BaseDirectory is: /usr.

InstallationDirectory
is: BaseDirectory/NX, i.e. /usr/NX.

Configuration files
Configuration files are /usr/NX/etc/server.cfg and /usr/NX/etc/node.cfg.

The Enterprise Terminal Server Node package also includes the nxserver binary and its server.cfg file. The nxserver binary doesn't work as an autonomous server. Nevertheless it allows to manage some configurations on the node host, also via its configuration file.

The command line interface
NoMachine server and node programs have a command line interface to execute operations.

You need to be a privileged system user to access all these functionalities. These commands can be run from an xterm or similar using the sudo utility or as root and without 'sudo'.

Invoke the 'nxserver' and 'nxnode' programs from /etc/NX, for example:

$ sudo /etc/NX/nxserver  --status
Printing the server and node usage doesn't require to be a privileged user, instead:
$ /etc/NX/nxserver  --help
$ /etc/NX/nxnode  --help
The 'nxserver --help' and 'nxnode --help' display the list of all the available commands and options and their description.

Online Resources
Visit the NoMachine Support Area to access a variety of online resources including the NoMachine Forums, tutorials and FAQs: https://www.nomachine.com/support. Or log in to your customer area to open a support enquiry.

Find a list of all documents and tutorials: https://www.nomachine.com/all-documents

Use the Knowledge Base search engine to access articles, FAQs and self-help information: https://kb.nomachine.com

Leave Feedback About This Guide
Our goal is to provide comprehensive and clear documentation for all NoMachine products. If you would like to send us your comments and suggestions, you can use the contact tool available at https://www.nomachine.com/contact-request, selecting Web Quality Feedback as your option.

2. Install, Update or Remove the Enterprise Terminal Server Node

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In order to have a fully working NoMachine setup immediately after installation and without the need for further operations, the installation procedure takes care of automatically starting all the required services, including the built-in Apache-based web server nxhtd. In order to work in all possible environments the nxhtd service as well as the Apache web server are configured to listen on all interfaces (0.0.0.0).

2.1. Prerequisites

Supported Operating Systems
Linux 32-bit and 64-bit
RHEL 6.0 to RHEL 9
CentOS 6.0 to CentOS 8.5
CentOS Stream 8 to CentOS Stream 9
SLED 11 to SLED 15
SLES 11 to SLES 15
openSUSE 11.x to openSUSE 15.x
Fedora 10 to Fedora 37
Debian 5 to Debian 11
Ubuntu 8.04 to Ubuntu 22.04

Hardware requirements
Intel Core2 Duo or AMD Athlon Dual-Core or equivalent
1 GB RAM
Network connection (either a LAN, or Internet link: broadband, cable, DSL, etc...)
Size required on disk:
Linux 195 MB

Software requirements
A desktop environment must already be installed. This applies also to headless Linux machines. Connections by the web and by NoMachine clients are supported.

Compatibility with older versions
Even if it's advisable to upgrade client installations to the same version 9 of the Enterprise Terminal Server and Enterprise Terminal Server Node, compatibility with clients v. 8 and 7 is preserved.

It's strongly advisable to keep version of Enterprise Terminal Server and of its Enterprise Terminal Server Nodes always aligned!

2.2. Linux Installations

Installing for the first time
You can install, update and uninstall using the graphical package manager of your Linux distribution or from command line by running commands from an xterm or similar with the sudo utility, or as root user if you don't have sudo installed. Instructions below refer to installation by command line.

If you own a customer license we recommend downloading the package from your Customer Area: https://www.nomachine.com/support#login.

Successive updates
The update procedure for server and node installations requires all NoMachine services to be stopped in order to correctly replace libraries and binaries. This implies that the node is not accessible to users during the update procedure. Current sessions on this node will be terminated, users will be able to connect again later.

There are two ways to update your current installation:

1. Automatic updates

   You can update your installation from our repositories. Just run the NoMachine User Interface from your Programs Menu and open the Server -> Settings -> Updates panel and click on the 'Check now' button. Follow the prompts to continue updating the software.NoMachine has the automatic check for updates enabled: it will check the repositories every two days to verify if updates are available. In this case, the server will prompt a dialog informing that a new version is available but it will never automatically update the current installation.Checking for updates can be disabled from that dialog by selecting the 'Don't ask again for this version' option or in the Updates panel by unchecking the 'Automatically check for updates' option.Detailed instructions for configuring the Automatic Updates are available in the Documents section on the NoMachine web site: https://www.nomachine.com/all-documents .

2. Update with NoMachine packages

   Alternatively, download the latest available package from the NoMachine web site and click on the executable file to launch Setup. As for the installation, Setup will guide you through all steps necessary for updating your installation.

   If you own a customer license we recommend you download the package from your Customer Area: https://www.nomachine.com/support#login.
   

2.3. RPM Packages

If you want to install to default location, namely /usr/NX/:

INSTALL

# rpm -ivh <pkgName>_<pkgVersion>_<arch>.rpm
To find out which NoMachine package you have installed (you will get the full name of the package), run:
# rpm -qa | grep nomachine

UPDATE

# rpm -Uvh <pkgName>_<pkgVersion>_<arch>.rpm

UNINSTALL

# rpm -e  nomachine-enterprise-terminal-server-node

For non-default locations, for example /opt/NX:

INSTALL

# rpm -ivh <pkgName>_<pkgVersion>_<arch>.rpm --prefix /opt

UPDATE

# rpm -Uvh <pkgName>_<pkgVersion>_<arch>.rpm --prefix /opt

UNINSTALL

# rpm -e nomachine-enterprise-terminal-server

2.4. DEB Packages

If you want to install to the default location, namely /usr/NX/:

INSTALL

$ sudo dpkg -i <pkgName>_<pkgVersion>_<arch>.deb
To find out which NoMachine package you have installed (you will get the full name of the package), run:
$ dpkg -l | grep nomachine

UPDATE

$ sudo dpkg -i <pkgName>_<pkgVersion>_<arch>.deb

UNINSTALL

$ sudo dpkg -r nomachine-enterprise-terminal-server-node

For non-default locations, for example /opt/NX:

INSTALL

$ sudo NX_INSTALL_PREFIX=/opt dpkg -i <pkgName>_<pkgVersion>_<arch>.deb

UPDATE

$ sudo NX_INSTALL_PREFIX=/opt dpkg -i <pkgName>_<pkgVersion>_<arch>.deb

UNINSTALL

$ sudo dpkg -r nomachine-enterprise-terminal-server

2.5. TAR.GZ Packages

If you want to install to the default location, namely /usr/NX/, ensure that package is placed there.

INSTALL

$ cd /usr
$ sudo tar xvzf <pkgName>_<pkgVersion>_<arch>.tar.gz
$ sudo /usr/NX/nxserver --install

UPDATE

$ cd /usr
$ sudo tar xvzf <pkgName>_<pkgVersion>_<arch>.tar.gz
$ sudo /usr/NX/nxserver --update

UNINSTALL

$ sudo /usr/NX/scripts/setup/nxserver --uninstall
$ sudo rm -rf /usr/NX

For non-default locations, for example /opt/NX:

INSTALL

$  sudo NX_INSTALL_PREFIX=/opt /usr/NX/nxserver --install

UPDATE

$ sudo NX_INSTALL_PREFIX=/opt /usr/NX/nxserver --update

UNINSTALL

$ sudo /opt/NX/scripts/setup/nxserver --uninstall
$ sudo rm -rf /opt/NX

2.6. Installing the License (for Customers)

Customer packages
include a temporary (30-days) server.lic file for evaluation.
This license file has to be replaced with the customer's license file acquired from NoMachine via the NoMachine UI in Settings -> Server -> Updates panel: click on 'Server subscription' to read the current license file. Click on 'Update subscription' at the bottom right to upload and install a new license file. You will be requested to log-in with a privileged account (administrator).

The Enterprise Terminal Server Node will cease to work once the license is expired. Nodes with an expired license are automatically excluded from the load balancing. If they are available for the manual node selection, they are still shown in the UI but their status is marked as 'failed' since they are unable to accept connections.

You may contact your NoMachine provider or the Support Team for renewal options.

To verify from command line that server.lic is correctly in place and check its validity, you can run:

$ sudo /etc/NX/nxserver --subscriptioninfo
$ sudo /etc/NX/nxserver --version

3. Setting-up a Multinode Environment

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Instructions to add the Enterprise Terminal Server node to your Enterprise Terminal Server or Enterprise Terminal Server Cluster are available in their guides at https://www.nomachine.com/all-documents

4. Initiating a NoMachine Connection (end-user's side)

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Pre-requisite: you need to have a valid account on the Enterprise Terminal Server and on the Enterprise Terminal Server Node host and the password cannot be empty. Your account can be a local account or a LDAP account or an AD account. NoMachine doesn't check if the source of the user's account information is for example LDAP or local account database. Be sure to configure the login in advance.

4.1. Connecting by Browsers or NoMachine Client

Once added to the Enterprise Terminal Server, the Enterprise Terminal Server Node is ready to go.

To connect via web, the end-user should point the browser on his/her device to the hostname or IP address of the Enterprise Terminal Server host.

In a similar way, when connecting form a client device, the user will have to specify the IP or hostname of the Enterprise Terminal Server while creating the connection.

By default, the NoMachine Enterprise Terminal Server makes available the Enterprise Terminal Server Node for the automatic load-balancing of virtual desktops. This means that the server, based on its load-balancing algorithm, will select the node where the new virtual desktop will be started. The server can be also configured to let the user choose the node.

More detailed instructions are available in the Enterprise Terminal Server guide, section 'Installation' at: https://www.nomachine.com/all-documents

4.2. Connecting Without an Account (Guest Desktop Sharing)^New!

This feature is mainly conceived for temporary and on-the-fly connections to the remote desktop, for example for remote assistance or for participating to a shared lesson on the desktop. It cannot be used in the case of unattended desktops because the deskop owner's approval is mandatory.

With Guest Desktop Sharing, users are able to connect to the remote desktop without the need to have a valid account on that host. The desktop owner must grant access by authorising the guest's connection request.

Guest Desktop Sharing is available for connections to Linux virtual desktops (Virtual Guest Desktop Sharing) and to the physical desktop (Physical Guest Desktop Sharing) of the server host.

This feature must be enabled on the Enterprise Terminal Server or Enterprise Terminal Server Cluster and will apply to all nodes.

5. Configuring Web Sessions

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Browser-based sessions can be configured further by enabling WebRTC and the built-in Apache web server according to your needs. It's also possible to use an alternative Apache server if you prefer. Web sessions must be configured on the Enterprise Terminal Server or Enterprise Terminal Server Cluster.

6. Compression Techniques and Optimizations

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This section describes how content of the remote screen is encoded in case of web sessions and client sessions and provides some hints for possible optimizations.

6.1. Video Stream Encoding in Web Sessions

In the case of web sessions, by default, session data is streamed in video frames compressed and decompressed by using the MJPEG lossy algorithm, which is the video-format widely supported by browsers.

Oher video codecs like VP8 and H.264, require a browser which supports WebRTC and HTML5.

NoMachine web sessions use H.264 video streaming when the following requirements are all met, otherwise VP8 is used.

1. WebRTC is enabled.
2. The browser supports WebRTC and the H.264 decoding

In practice, when WebRTC is enabled, H.264 or VP8 encoding will be used (if the browser supports WebRTC), otherwise the classic web media exchange protocol will be used and MJPEG will be the codec.

H.264 hardware encoding is possible when the Enterprise Terminal Server host machine has an hardware accelerated video card (GPU) with Nvidia Kepler microarchitecture onward or Intel Quick Sync processors.
Enabling HW acceleration by Quick Sync requires a manual configuration however, as explained here: https://www.nomachine.com/AR09O00938

Optimizations
Optimizations can be done in two ways: (I) by adjusting display settings in the session or (II) by enabling WebRTC.

1. Adjusting display settings in the web sessions
   To access NoMachine display settings, open the NoMachine menu inside the web session: press ctrl+alt+0 or click on the page peel in the upper right corner of the window to open it. Then click on the 'Display' button and finally on 'Display settings'. From this panel you can do the following.
   
   Change the display image quality
   Increasing the quality will mean to apply a minor compression ratio, the image will be clearer, but more bandwidth will be used.
   
   Disable network-adaptive display quality
   This will anchor the display quality to the fixed value specified in the Display quality slider, making it independent from the current network congestion. This is not recommended when there is a very limited bandwidth.
   
   Disable multi-pass display encoding
   Default settings within the encoding will work to refine the image progressively to the target quality (as specified in the Display quality slider) starting from a lower quality version of the image during moments of inactivity of the desktop. Disabling this refinement sends the image directly with target quality. Not recommended when there is limited bandwidth.
2. Enabling WebRTC
   NoMachine web sessions use by default the classic web media exchange protocol for two-way browser/web server communication. WebRTC (Real-Time Web Communication) is also supported and can be enabled as explained in the next paragraph.
   Enabling WebRTC allows to use the H.264 video streaming (when possible) or VP8 which optimize the user experience with multimedia applications and content.

You may verify which encoding method is in use from the NoMachine menu inside the session: press ctrl+alt+0 or click on the page peel in the upper right corner of the window to open it. Then click on the 'Display' button and finally on 'Display settings'. The codec actually in use is reported at the bottom left of the menu.

6.2. Video Streaming Encoding in Client Sessions

Sessions run by NoMachine client use a combination of video and image encoding based on standard codecs and a number of techniques developed by NoMachine. Frames are encoded into a video stream optimized by means of a compression and decompression algorithm of real-time image and audio data. VP8, H.264 and MJPEG encoding are supported.

In general, VP8 and H.264 are suitable for all situations, while MJPEG can be an alternative when the end-user's computer is less powerful and the user is experiencing slow responsiveness.

The display encoder can be changed on the server:

from the User Interface
In the Settings -> Server -> Performance panel, select 'Use a specific display encoding' and choose it from the list.

or in the node configuration file
Enable the use of a specific codec by editing the node configuration file and enabling the following two keys:
EnableDisplayServerVideoCodec 1
DisplayServerVideoCodec CODEC

where CODEC can be: 'vp8','h264' or 'mjpeg'. For example:
EnableDisplayServerVideoCodec 1
DisplayServerVideoCodec mjpeg

6.3. The X11 Vector Graphics Mode in Client Sessions

The X11 vector graphics mode is enabled by default for (i) virtual desktops and (ii) custom sessions in floating window mode. This mode is mainly a set of NoMachine techniques to compress and optimize the X11 protocol (by applying the same algorithms available with the NX compression protocol v. 3). These compression techniques are applied to all non-video content like textual elements, while multimedia content is encoded in a video stream (VP8 or H.264).

The X11 vector graphics mode is useful for avoiding loss of image quality and in general is the best option when working with traditional User Interfaces or a large amount of text. However it's not advisable for multimedia content or applications with many graphical effects.

This mode can also help to reduce bandwidth usage, decrease the HW requirements on client and server (expensive video encoding/decoding operations are applied only to multimedia content), and increase responsiveness on slow link and end-users' clients without hardware accelerated video encoding/decoding capabilities.

You can disable/enable the X11 vector graphics mode
via the User Interface
in the Server -> Settings -> Performance panel by selecting or not the 'Use X11 vector graphics mode in virtual sessions' option.

or in the node configuration file
Edit the node configuration file, uncomment and set the AgentX11VectorGraphics key to '0' for disabling the the X11 vector graphics mode:
AgentX11VectorGraphics 0

or to enable it:
AgentX11VectorGraphics 1

In the case of slow bandwidth, decreasing the quality level of images could help but if you need to have a perfect image without loss of quality, you should increase the display quality instead. It's also suggested to disable multi-pass encoding to avoid the 'out of focus' effect: multi-pass is an encoding technique which uses multiple passes to progressively reach the best definition of the image.

Quality level and multi-pass encoding can be tuned from the NoMachine menu inside the session in the Display -> Change settings panel. (Ctrl+alt+0 or click on the right upper corner of the window to open the NoMachine menu).

6.4. Supporting OpenGL Applications in Virtual Sessions

In NoMachine virtual desktops and custom sessions, OpenGL rendering is done by default by software components. This means that rendering tasks are accomplished by CPU and not offloaded onto the GPU. Such operations can be resource-intensive, especially in the case of 3D desktop graphics effects, and make the user interface look slow.

A possible alternative is to configure the NoMachine server to use the VirtualGL libraries (included in the NoMachine package) and therefore enable support for HW accelerated OpenGL applications. This allows OpenGL applications, namely 3D applications, to use server side graphics hardware.

In order to activate support for VirtualGL, follow instructions at https://kb.nomachine.com/AR05P00982.

7. Server Configuration

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7.1. Configuration Files

The configuration file for the nxserver and nxweplayer/nxwebrunner programs is server.cfg. The configuration file for the nxnode program is node.cfg.

They are placed in (default installation):
/usr/NX/etc/server.cfg
/usr/NX/etc/node.cfg

The Default Configuration
NoMachine servers come with a default configuration that grants a working setup for the majority of environments. NoMachine administrators can tune their installation at any moment and according to their specific needs by setting the related configuration keys. In some cases this will require to restart all NoMachine services.

Edit the Configuration Files
NoMachine configuration files are text files made up of a number of key-value pairs. All the configuration files can be edited manually by a text editor, e.g. 'vi'.

Be sure to uncomment the configuration key (i.e., remove the '#' pre-pended to the key) to set a different value to the default one.

When a configuration key supports an on/off status, set value to '0' to disable it and to '1' to enable it.

Make Changes to the Default Configuration Effective
Changes will be effective with the next new virtual desktop or custom session without the need to restart the server if not otherwise specified.

8. Services Management

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Installation and upgrade procedures take care of configuring and starting all the necessary services to make the server ready to accept and serve user's requests for virtual desktops and custom sessions. The necessary services are configured to be restarted at each reboot of the host machine.

8.1. Disabling Access to the Desktop ('Desktop shared/Desktop not shared')

When you are sitting in front of the computer where the server is installed or you're connected there by NoMachine, you can switch off/on the ability to accept connections to the physical desktop via NoMachine by toggling 'Desktop shared/Desktop not shared'.

You can configure this setting via the NoMachine Monitor menu (right click on the !M icon in the system tray to open it). By selecting 'Desktop not shared', nobody can connect.

This setting lasts until you change it again, even when you physically log out from the system.

See also this tutorial for more details: https://www.nomachine.com/disabling-access-to-your-local-desktop

It's possible to hide the 'Desktop shared/Desktop not shared' items from the !M menu by configuring the NoMachine node.cfg file on that computer and setting:
EnableAcceptingConnections 0
Be sure to remove the pre-pending # from the key name.

8.2. Stopping and Starting Services

All NoMachine services can be stopped via:

the User Interface
all NoMachine services can be stopped by the Settings -> Server -> Server status panel ('Shut down the server'). When doing so, you will be asked if services must be started at the next reboot or not. You can restart services also from the Server status User Interface ('Restart the server').

or from command line.

Stopping all the NoMachine services

$ sudo /etc/NX/nxserver --shutdown
This will completely disable access to the server host machine and  terminate all sessions running on that host. By default, all  services will be restarted when the machine is booted. To override this  behavior, specify the --start-mode option when stopping the services:
$ sudo /etc/NX/nxserver --shutdown --start-mode manual

Starting NoMachine server and services

$ sudo /etc/NX/nxserver --startup
All services will be restarted at the next reboot. To not start services when the machine is rebooted, specify the start mode while running the --startup command:
$ sudo /etc/NX/nxserver --startup --start-mode manual

Specifying the start mode
It's possible to set the 'start mode' (if services will be started automatically at boot or not) by using:

$ sudo /etc/NX/nxserver --startmode manual
or:
$ sudo /etc/NX/nxserver --startmode automatic

Stopping and restarting NoMachine server and services

$ sudo /etc/NX/nxserver --restart

8.3. Stopping and Starting nxd and nxhtd

These are the NoMachine services listening for connections:

Program	Default port	Scope
nxd	4000	Accept connections by NX protocol
nxhtd	4443	Accept connections by HTTPS protocol (connections by the web)

You can stop a single service:

via the User Interface
in the Settings -> Server -> Ports panel. You can also choose the start mode: whether the service has to be started automatically at the next boot or not.

or from command line.

Stopping a service

$ sudo /etc/NX/nxserver --stop SERVICE

where SERVICE can be:
nxd, the Network Server for accepting connections by NX protocol
nxhtd, the NoMachine web server for web sessions

Starting or restarting a service

$ sudo /etc/NX/nxserver --start nxd
$ sudo /etc/NX/nxserver --start nxhtd
or:
$ sudo /etc/NX/nxserver --restart nxd
$ sudo /etc/NX/nxserver --restart nxhtd

Specifying the start mode
By default each service is automatically restarted at the next boot. You can configure that on a per-service basis by running:

$ sudo /etc/NX/nxserver --startmode SERVICE manual
or to restore the default behavior:
$ sudo /etc/NX/nxserver --startmode SERVICE automatic

The commands above operate on the configuration keys listed below. You can change them manually in the server configuration.

Configuration	Key setting
Enable automatic starting of the NX Network server, nxd	StartNXDaemon Automatic
Disable automatic starting of the NX Network server, nxd	StartNXDaemon Manual
Enable automatic starting of the NoMachine web server, nxhtd	StartHTTPDaemon Automatic
Disable automatic starting of the NoMachine web server, nxhtd	StartHTTPDaemon Manual

8.4. Local and Network Ports

For each session, NoMachine uses ports that are used only locally on the server host and network ports.

Some ports are mandatory and must be available, e.g. the session display number and the connection port. Other ports are used for services that can be disabled (e.g. USB forwarding, UDP communication).

Local port	Description	How to change the default
11000 + DisplayBase	Session display. If this port is already in use, NoMachine will look for a free port by incrementing DisplayBase up to the value set in the DisplayLimit server configuration key.	DisplayBase (by default 1001) and DisplayLimit (200) are defined in server.cfg
20000	Communication port between the session's nxserver process and the main server process.	Add the ServerSlaveBase key to the end of server.cfg and specify a value
24000 + DisplayBase	Session's monitor port.	DisplayBase (by default 1001) and DisplayLimit (200) are defined in server.cfg
5473 and 5483	USB devices forwarding.	Disable USB sharing by setting EnableUSBSharing none in node.cfg

Network port	Description	How to change the default
6000 + DisplayBase	TCP port for the NoMachine display service. If this port is already in use, NoMachine will look for a free port by incrementing DisplayBase up to the value set in the DisplayLimit server configuration key.	DisplayBase (by default 1001) and DisplayLimit (200) are defined in server.cfg.
5353	UDP port for the MDNS service to broadcast computer's information over the LAN.	Disable the service by setting EnableLocalNetworkBroadcast 0 in server.cfg.
4000	TCP port for the NoMachine Network service (nxd) and connections via NX protocol. This port must be open in the firewall and mapped to the external IP of the server host.	Set NXTCPPort in server.cfg and restart the nxd service.
4000	Port for UDP communication for connections via NX protocol.	Set NXUDPPort in server.cfg and restart the nxd service. It can be changed also in the server administration UI.
22	TCP port for connections via SSH protocol. This port must be open in the firewall and mapped to the external IP of the server host.	Set a different port for the system SSH server and align value set for SSHPort in server.cfg. Then restart the NoMachine server.
4443	HTTPS port for web connections. This port must be open in the firewall and mapped to the external IP of the server host.	See https://www.nomachine.com/AR07S01137
20000 - 30000	External ports range for UPnP port mapping.	Set NXTCPUPnPPort in server.cfg to define a different range. Set EnableUPnP none in server.cfg to disable port mapping.
5040 + x	Port opened between client and server for each USB device. Port number is defined by 5040 + x where 'x' is the first free port retrieved starting from port number 5040.	N/A
4000	Automatic updates from NoMachine repositories.	Updates are managed by nxd. Disable automatic updates by setting UpdateFrequency 0 in server.cfg.
5473 and 5483	USB devices forwarding.	Disable USB sharing by setting EnableUSBSharing none in node.cfg.

8.5. Hiding Server Settings or the !M Icon from the System Tray

It is possible to hide or show the 'Show server status' item displayed in the !M (the Monitor) menu in the system tray.

This can be done by setting in the node configuration:
EnableServerStatus 0

Then restart NoMachine server, via UI or from command line:

$ sudo /etc/NX/nxserver --restart

It's also possible to hide the possibility to access server settings via UI. Edit the node.cfg file and set:
EnableServerPreferences 0

It's not necessary to restart the server, but if you have already the NoMachine UI open, close and re-open it to make changes effective.

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To hide settings for the Server in the UI, set both EnableServerStatus 0 and EnableServerPreferences 0. If you have the client UI (main window and/or session window open), close and reopen it to make changes effective.

It is possible to hide or show the !M (the Monitor) icon of the server in the system tray. When the icon is hidden, notification messages will still be displayed when users are connecting.

This can be configured in the node configuration file.

To hide the !M in the system tray set:
DisplayMonitorIcon 0

To display the !M in the system tray set:
DisplayMonitorIcon 1

In both cases, then restart the server, via UI or from command line as described above.

8.6. Hiding the Whiteboard and Chat Tools

If you want to disable the Whiteboard from the Monitor menu, edit the node configuration file to have:
EnableWhiteboard 0

Then restart the server:

$ sudo /etc/NX/nxserver --restart

9. Notifications to Users

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This section explains how to use the NoMachine whiteboard to exchange messages with the connected users or the server tools to notify users for example about incoming maintenance operations.

9.1. Whiteboard and Custom Notifications

NoMachine provides an instant messaging tool, named whiteboard which also allows drawing, the sharing of files with connected users and fast-track access to file transfer. To access it, connect to the user's desktop and from the Monitor (!M icon) in the system tray click on 'Show the whiteboard'. Note that if multiple users are connected at the same time to the same session, they will all see the same message.

As an alternative, it's possible to issue a dialog in the connected sessions to show a custom message by sending it from command line.

Sending a message:

to all running sessions:
$ sudo /etc/NX/nxserver --broadcast "Your message goes here"
or sending a message only to the session specified by its session id:
$ sudo /etc/NX/nxserver --message  SESSION_ID  "Your message goes here"

9.2. Greeting Messages (for Virtual Desktops)

It is possible to welcome users when the virtual desktop has started by issuing a greeting message, either only the first time the user logs-in or every time the user connects to the Enterprise Terminal Server. Update the node configuration file by writing the text of your message in any of the following keys:
NodeFirstLoginGreeting "Welcome to your first NX session"
NodeLoginGreeting "Welcome to your NoMachine session"

10. Supported Connection Protocols and Authentication Methods

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NX Protocol
connections by default use the NX protocol which is its own protocol for secure communication over the network. Encryption in the NX protocol is implemented using OpenSSL TLS/SSL, based on ECDHE-RSA-AES128-GCM-SHA256 as the default cipher suite. ECDHE-RSA-AES128-GCM-SHA256 is an AES (Advanced Encryption Standard) block cipher with 128 bits key in GCM (Galois/Counter Mode). RC4 (ECDHE-RSA-RC4-SHA cipher suite) is used as backward compatibility when connecting from or to versions 4.0.

When using the NX protocol, NX data can travel on TCP and UDP streams, even at the same time. The client and server can decide dynamically what transport to use, based on the type of data and the network conditions. Client and server negotiate the UDP transport at session startup, after having negotiated the main TCP link. UDP uses symmetric Blowfish encryption, with key negotiated on the secure TCP link. UDP is presently not available when using SSH tunneling to ensure that all data goes through the same SSH link, as it was in legacy version 3. UDP protocol can be also disabled.

SSH Protocol
NoMachine Enterprise Terminal Server also provides tunneling of connections using SSH and full integration with any authentication backend supported by the host SSH server.

10.1. Supported Server-Node Connection Protocols

Client connections are tunneled from the Enterprise Terminal Server to the Enterprise Terminal Server Node. Server-node connections use by default the NX protocol for secure communication over the network (default listen port is 4000).

As an alternative, it's possible to tunnel server-node connections using SSH (default listen port is 22).

The protocol, as well as the port if different from the default one, has to be defined while the Enterprise Terminal Server Node is added on the Enterprise Terminal Server.

10.2. Changing port for the NX Protocol

The default port for nxd is 4000.

If you change the port for nxd, be sure to specify that port while adding the Enterprise Terminal Server Node to the Enteprise Terminal Server. To modify it later, remove and re-add the node with the new port value.

It's possible to modify the port for nxd
from the User Interface
in the Settings -> Server -> Ports panel

or in the server configuration file by editing this key:
NXTCPPort 4000

Restarting the nxd service is necessary to make this change effective:

$ sudo /etc/NX/nxserver --restart nxd

10.3. Changing Port for the SSH Protocol

The default port used for the SSH protocol is 22 on Linux. On such platform NoMachine relies on the SSH server installed on the system. If your SSHD is configured to listen on a port different from 22 you need to align the NoMachine server configuration accordingly. Connecting users will have to specify such value in their connection settings in the player User Interface.

If your SSH server is listening on a port different than 22, change the SSH port via UI in the Settings -> Server -> Ports panel

or in the server configuration file by editing this key:
SSHPort 22

11. Local Users Management

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System accounts can have different NoMachine-related privileges, they can become trusted users or administrators and have always access to the physical desktop of the server, even without the need of the owner's approval.

11.1. Managing Local System Accounts on the Server Host

To be able to login to the Enterprise Terminal Server Node host, you need to have a valid account on that host and the password cannot be empty. Your account can be a local account or a LDAP account or an AD account. NoMachine doesn't check if the source of users' account information is for example LDAP or local account database. Be sure to configure the login in advance.

You can create a local account by means of system tools, or via command line by using the 'nxserver' commands:

$ sudo /etc/NX/nxserver --useradd USERNAME --system

Modifying the User's Password
You can modify the user's system password by running:

$ sudo /etc/NX/nxserver --passwd USERNAME --system

11.2. Using Virtual Desktop Guests (System Guest Users Accounts)

The automatic generation of guest accounts is not enabled by default. It must be enabled on the Enterprise Terminal Server or Enterprise Terminal Server Cluster and it will apply to all nodes.

12. Session Management

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Each session on the same server is uniquely identified by a session id (which can look like: B253864E822F5A235825F3AB8853AF00) and a display id (e.g. 1002).

A session on the NoMachine Enterprise Terminal Server Node can be in any of the following statuses:
Connected - when it's connected to the remote display.
Disconnected - this status is available only for virtual desktop sessions and custom sessions. A session is marked as disconnected when it's disconnected from the remote display. A disconnected session can be reconnected at any time even from a different machine (migration). While a session is disconnected, applications on the remote server stay running. Finished - the session has been closed in a clean way and all NoMachine processes have been shut-down smoothly.
Failed - any of the NoMachine processes has failed to start or it has been "un-cleanly" terminated.
Transitional statuses are Connecting, Disconnecting and Terminating.

12.1. Forcing Session Termination

Sessions are centrally managed by the Enterprise Terminal Server or Enterprise Terminal Server Cluster, they can be listed and in case manually terminated by the main server.

On the node it's possible to apply specific configurations to force the automatic disconnection or termination of sessions running on this node.

Disconnecting or Terminating Virtual Desktops Automatically

To disconnect a virtual desktop or custom sessions after a certain time of inactivity, uncomment and set a proper timeout value, in seconds, in the following node configuration key. For example, if you want to terminate sessions after 10 minutes of inactivity you need to set:
DisplayServerExtraOptions "-timeout 600"

If the NoMachine display agent doesn't receive any input from the user in the given timeout, it will either disconnect or terminate the session. Termination of the session will be carried out if the session is not persistent or no X application is connected to the display. Otherwise the agent will disconnect the session so that the X applications will be left running.

Note that the DisplayServerExtraOptions key is only for virtual desktops or custom sessions with X11 vector graphics enabled (default).

For web sessions, sessions connected to a virtual desktop (sharing of the virtual desktop), virtual desktops with X11 vector graphics disabled and connections to the physical desktop, set instead:
DisplayAgentExtraOptions "-timeout 600"

Automatically Terminating Virtual Desktop/Custom Sessions in Status Disconnected

It's possible to specify for how long the server has to keep alive virtual desktops in the disconnected status. When the time has expired, the server will terminate virtual desktops if no user is connected there. To let the server terminate a disconnected virtual desktop after XXX seconds, edit the server configuration file, uncomment and set the timeout value (XXX) expressed in seconds in the following key:
DisconnectedSessionExpiry XXX

For example, by setting:
DisconnectedSessionExpiry 600
a virtual desktop will terminate after ten minutes provided there is no activity.

Automatically Terminating Virtual Desktop/Custom Sessions when the Maximum Number is Reached

To terminate a disconnected session when the maximum number of virtual desktops (see 'Limiting the Number of Virtual Desktops' below) is reached and make room for a new virtual desktop or custom session, enable the following key in the server.cfg file:
EnableAutokillSessions 1

Limiting the Number of Virtual Desktops or Custom sessions

You can set a limit for the number of virtual desktops provided so that the limit does not exceed the number of connections allowed by the server license value (it's the 'Virtual Desktops' field in the server.lic file). NoMachine Enterprise Terminal Server allows unlimited concurrent virtual desktops

For example to configure the server to allow only two concurrent virtual desktops, edit the server configuration and set:
VirtualDesktopsLimit 2

You can also specify how many virtual desktops a single user may run. For example, to allow 1 connection per-user, uncomment and set the following key in the server configuration file:
VirtualDesktopsUserLimit 1

A Practical Example
Limit the number of virtual desktops to three and keep alive a virtual desktop (inactive & disconnected) for one day. If a new virtual desktop is requested, the server will terminate the oldest virtual desktop in status disconnected to make room for the new session.
VirtualDesktopsLimit 3
EnableAutokillSessions 1
DisconnectedSessionExpiry 86400

Automatic Disconnection of Users

The automatic disconnection is a server configuration to rule the server behavior when the limit of users is exceeded and a new user is requesting to connect.

Current options are:
disabled (0): this is the default. The server will issue a pop-up message before disconnecting the user. The current user can accept or not to disconnect itself. If no choice is made, the server will automatically disconnect this user and let the incoming user to connect.
enabled (1): the server will automatically disconnect the user to make room for the new user. No message is issued to the already connected user.
none (2): the server will prompt the connected user to accept or refuse to disconnect for making room for the incoming user. If no choice is made, the server doesn't disconnect the user and advise the incoming user that the maximum number of allowed connections is reached.
silent (3): the server never notifies desktop owners about incoming users, incoming users are informed that the maximum number of allowed connections is reached.

The automatic disconnection applies when the maximum number of available connections to the desktops or the maximum number of available virtual desktops is exceeded.

To enable the automatic disconnection set the following key in the server.cfg file:
AutomaticDisconnection 1

To let the connected user decide or refuse to disconnect, set:
AutomaticDisconnection 0

12.2. Using Any of the Available Desktop Environments

Pre-requisite to connect using NoMachine is that a desktop environment is installed on the system even if the host is headless or not started in graphics mode.

By default when the user chooses to create a new virtual desktop, NoMachine runs the default X session set on the system.

During its installation, NoMachine detects the default desktop environment set on the system and configures the node accordingly. Path and command to start the system desktop environment is defined in /usr/NX/etc/node.cfg by the DefaultDesktopCommand key. The Enterprise Terminal Server is able to detect GNOME, Unity, KDE, LXDE and Xfce. If you have a different desktop environment, you can edit the DefaultDesktopCommand key accordingly.

For example to run MATE:
DefaultDesktopCommand "/usr/bin/mate-session"

or to run Pantheon:
DefaultDesktopCommand "/usr/bin/gnome-session --session=pantheon"

If there are multiple desktop environments, you can configure NoMachine to provide users the list of all the available desktop types installed and configured on the system (i.e. available in /usr/share/xsessions).

To enable that, set 'xsessions=1' in the ConnectPolicy key in /usr/NX/etc/server.cfg:
ConnectPolicy autocreate=1,autoconnect=1,automigrate=1,desktop=0,dialog=0,xsessions=1,udp=1
Be sure to remove the pre-pending # from the key name.

If you want provide a choice between GNOME and KDE only, and/or if you want to provide XDMsessions, you can set:
ConnectPolicy autocreate=1,autoconnect=1,automigrate=1,desktop=1,dialog=0, xsessions=0,udp=1

To run GNOME and/or KDE, ensure that the appropriate command is set in the corresponding keys in node.cfg, for example
CommandStartGnome "/etc/X11/Xsession 'gnome-session --session=gnome'"
CommandStartKDE "/etc/X11/Xsession startkde"

To configure XDM sessions, read here: https://kb.nomachine.com/AR06Q01035

12.3. Activating the Disconnect/Terminate Dialog

Terminating a virtual desktop session is done at the system level of the Enterprise Terminal Server host. For example, if you are running a virtual desktop session (Gnome), you terminate the session by choosing the logout option from Gnome's system menu.

Disconnecting the session is done by clicking the 'X' button in the upper corner of the window. Alternatively, you can disconnect via the NoMachine session menu panel (Ctrl-Alt-0 -> Connection -> Disconnect).

It's possible to display a dialog to let the user decide whether to disconnect or terminate the virtual desktop session when clicking on the X button which closes the session window.

The Disconnect/Terminate dialog is available for:

1. virtual desktops running in X11 vector graphics mode
2. virtual desktops not running in X11 vector graphics mode
3. virtual custom sessions

To enable the Disconnect/Terminate dialog, enable the 'dialog' option (i.e. set dialog=1) in the following key in server.cfg:
ConnectPolicy autocreate=1,autoconnect=1,automigrate=1,desktop=0,dialog=1,xsessions=0,udp=1

12.4. Server Automation Interface: Custom Scripts executed on Server/Node Events

The server configuration provides a number of keys that can be activated to execute a custom script upon a certain event. According to the event, a number of parameters can be specified for each script. In a similar way, a number of keys is present in the node configuration file to allow to execute a custom script on a certain NoMachine node event. In both cases and according to the event, a number of parameters can be specified for each script. Value of parameters are listed in a positional order and corresponds to $1,$2,$3 etc … For example, a basic script on Linux to be executed in UserScriptAfterLogin key allows to retrieve the name of the user who is logged (username) and the IP of his/her machine (remote IP):

#!/bin/sh
username=$1
remoteIP=$2
echo "$username $remoteIP"  >> /tmp/UserScriptOutput.log

Available for	Configuration key	Parameter $1,$2 etc ... (server.cfg)	Parameter $1,$2 etc ... (node.cfg)
server	UserScriptBeforeLogin	remote ip	-
server	UserScriptAfterLogin	username, remote ip	-
server	UserScriptAfterLogout	username, remote ip	-
server,node	UserScriptBeforeSessionStart	session id, username, node host, node port, main session id(*), main session type(*)	session id, username, session type, display, main session id(*), main session type(*)
server,node	UserScriptAfterSessionStart	session id, username, node host, node port, main session id(*), main session type(*)	session id, username, session type, display, main session id(*), main session type(*)
server,node	UserScriptBeforeSessionDisconnect	session id, username, node host, node port	session id, username, session type, display
server,node	UserScriptAfterSessionDisconnect	session id, username, node host, node port	session id, username, session type, display
server,node	UserScriptBeforeSessionClose	session id, username, node host, node port, main session id(*), main session type(*)	session id, username, session type, display, main session id(*), main session type(*)
server,node	UserScriptAfterSessionClose	session id, username, node host, node port, main session id(*), main session type(*)	session id, username, session type, display, main session id(*), main session type(*)
server,node	UserScriptBeforeSessionReconnect	session id, username, node host, node port	session id, username, session type, display
server,node	UserScriptAfterSessionReconnect	session id, username, node host, node port	session id, username, session type, display
server	UserScriptBeforeSessionFailure	session id, username, node host, node port,main session id(*), main session type(*)	-
server,node	UserScriptAfterSessionFailure	session id, username, node host, node port,main session id(*), main session type(*)	session id, username, session type, display, main session id(*), main session type(*)
server	UserScriptBeforeCreateUser	username	-
server	UserScriptAfterCreateUser	username	-
server	UserScriptBeforeDeleteUser	username	-
server	UserScriptAfterDeleteUser	username	-
server	UserScriptBeforeEnableUser	username	-
server	UserScriptAfterEnableUser	username	-
server	UserScriptBeforeDisableUser	username	-
server	UserScriptAfterDisableUser	username	-

(*) 'main session id' and 'main session type' parameters are available only when the user connects to an already running virtual desktop (session shadowing). They indicate the id and type of the session to which the user is connected with his/her own session qualified by 'session id' and 'session type' respectively.

A further key in the node configuration file, allows to run a custom script triggered on change resolution events (resize of the remote screen). The related key is:
UserScriptAfterRemoteResize

Note that the order of parameters is relevant. For example, a custom script to be run on node event 'UserScriptBeforeSessionStart' should use the $2 variable to retrieve username and $4 to retrieve display.

Pre-requisites to run custom scripts
Custom scripts must be executable. Custom scripts set-up in server.cfg are common to all the users who are accessing the server and are executed by the nxserver program. Since nxserver is running as the nx user, you have to grant this user the necessary permissions in order to execute the custom script.

Custom scripts set-up in node.cfg are executed by the nxnode program, which is run as the connected user. Place the script in a directory that is accessible by the node, i.e. accessible by the connected user(s).

By default if the execution of the scripts fails, the nxserver and nxnode will terminate. This means that the user's session will not start. You can override this behavior by forcing exit 0 inside the custom script and let the session start even if the custom script is failed.

12.5. Accessing Remote Desktops by RDP

RDP sessions are encapsulated inside a virtual desktop session and they use the RDP client. So, prerequisite is that this RDP client (by default rdesktop) is installed on the node host machine, where the NoMachine RDP virtual desktop will be run.

Note that behaviour of RDP sessions is strictly related to features supported by the RDP client. For example, running a Windows application as a single application is possible only if the version of the RDP client supports it.

Support for RDP sessions must be enabled in NoMachine Enterprise Terminal Server or Enterprise Terminal Server Cluster. To enable it, please follow instructions at: https://www.nomachine.com/AR07J00645

12.6. Accessing Remote Desktops by VNC

VNC sessions are encapsulated inside a virtual desktop session and they use the VNC client. So, prerequisite is that this VNC client (by default vncviewer) is installed on the node host machine, where the NoMachine VNC virtual desktop will be run.

Note that behaviour of VNC sessions is strictly related to features supported by the VNC client.

Support for VNC sessions must be enabled in NoMachine Enterprise Terminal Server or Enterprise Terminal Server Cluster. To enable it, please follow instructions at: https://www.nomachine.com/AR10K00720

13. Collaborative Virtual Desktops and Connections to the Physical Desktop

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This section deals with the possibility to share your own remote desktop with other users, included guests, for example for remote assistance or collaboration. Request for desktop owner's authorization is configurable depending on the type of users (guest users always need the explicit approval to connect). Sessions can be in interactive or view-only mode. Allowing connections in interactive mode grants the user full access to the desktop resources and applications. View-only mode is suggested for example when making presentations or teaching a lesson.

13.1. Sharing Virtual and Physical Desktops

By default users can connect to their virtual desktops and to virtual desktops owned by other users as well as to physical desktop of the remote computer. Different users can share the same desktop and access all applications and resources interactively, or assist in view-mode only.

When the desktop owner is different from the connecting user, he/she is always required to authorize the incoming request for connection. Authorization is not requested when the incoming user and the desktop owner are the same. Also system administrators, NoMachine administrators and NoMachine trusted users can connect without explicit authorization.

With the new Guest Desktop Sharing, the desktop owner can authorize a user to connect to the desktop without needing an account for that user. See the relative paragraph in this guide for more details.

Configurations made via the UI apply to connections to physical and virtual desktops. If you want to set a separate configuration for these desktops, you have to edit the server configuration manually.

Rather than allow all users to connect without virtual desktop's owner authorization or click accept for every single user which would like to connect, it is possible to define in advance a number of trusted users who don't need the specific owner's permission. See the relative paragraph.

13.2. Authorization and Interaction Level for Virtual Desktop Sharing

Configuring access authorization

It's possible to configure via UI if system users need or not the desktop owner's approval to connect. Guest users need always the approval.

To configure access for system user, open Settings -> Server -> Security and enable/disable options: 'Don't require acceptance if the user logged in as the owner of the desktop' and 'Don't require acceptance if the user logged in as a system user'.

Settings via UI applies to both virtual and physical desktops.

Otherwise set behaviour only for virtual desktops via configuration in server.cfg. Default corresponds to the following settings:
VirtualDesktopAccess owner,system,trusted,administrator
VirtualDesktopAccessNoAcceptance owner,trusted,administrator

The VirtualDesktopAccess key in server.cfg (which replaces the VirtualDesktopSharing key available in previous versions) accepts a comma-separated list of values to define which kind of user is allowed to connect to the virtual desktops running on the NoMachine server host.

Accepted values are (order of values is not relevant):
VirtualDesktopAccess owner,system,trusted,administrator,guest

administrator: system adminstrators and NoMachine administrators
trusted: NoMachine trusted users for connections to the virtual desktops (nxserver --useredit USERNAME --trusted virtual)
system: all unprivileged users who have a valid account to log-in, included System Guest Users who have a system account generated automatically on demand. They are available only on Linux with NoMachine Terminal Server and Enterprise Terminal Server.
owner: the owner of the remote desktop
guest: Guest Desktop Sharing users (which don't have a system account)

The VirtualDesktopAccess key has to be used in conjunction with the VirtualDesktopAccessNoAcceptance key (previously named VirtualDesktopAuthorization) to define which user can access the remote desktop without the desktop owner's authorization. This key accepts:

VirtualDesktopAccessNoAcceptance owner,system,trusted,administrator

Configuring interactive or view-only mode

It's possible to configure if users will connect in interactive mode or view-only mode via the UI in the Settings -> Server -> Security panel choose 'Only allow connections in view-only mode'

Otherwise you can forbid users to interact with the desktop once connected via configuration by setting in server.cfg:
VirtualDesktopMode 0

To allow full interaction instead, ensure to have:
VirtualDesktopMode 2

A further setting allows instead the connected user to interact with the desktop except for resize operations:
VirtualDesktopMode 1

13.3. Disabling Virtual Desktop Sharing

By default users can connect to virtual desktop sessions owned by a different user. To forbid this capability, set in the server configuration file:
VirtualDesktopAccess none

This setting also disables the listing of other user's virtual sessions in the client User Interface.

13.4. Authorization and Interaction Level for Physical Desktop Sharing

Configuring access authorization

It's possible to configure via UI if system users need or not the desktop owner's approval to connect. Guest users need always the approval.

To configure access for system user, open Settings -> Server -> Security and enable/disable options: 'Don't require acceptance if the user logged in as the owner of the desktop' and 'Don't require acceptance if the user logged in as a system user'.

Settings via UI applies to both virtual and physical desktops.

Otherwise set behaviour only for physical desktop via configuration in server.cfg. Default corresponds to the following settings:
PhysicalDesktopAccess owner,system,trusted,administrator
PhysicalDesktopAccessNoAcceptance owner,trusted,administrator

All users - except guests - can request to connect to the physical desktop owned by another user. The approval of the desktop owner is always requested, except for NoMachine trusted users and administrators and when the connecting user is the desktop owner.

The PhysicalDesktopAccess key in server.cfg (which replaces the PhysicalDesktopSharing key available in previous versions) accepts a comma-separated list of values to define which kind of user is allowed to connect to the physical desktop of the NoMachine server host.

Accepted values are (order of values is not relevant):
PhysicalDesktopAccess administrator,trusted,system,owner,guest

administrator: system adminstrators and NoMachine administrators.
trusted: NoMachine users trusted for connections to the physical desktop (nxserver --useredit USERNAME --trusted physical)
system: all unprivileged users who have a valid account to log-in
owner: the owner of the remote desktop
guest: Guest Desktop Sharing users (which don't have a system account) and System Guest Users (who have instead a system account generated automatically on demand. This type of user is available only on Linux with NoMachine Terminal Server, Enterprise Terminal Server and Enterprise Terminal Server Cluster).

Configuring interactive or view-only mode

It's possible to configure if users will connect in interactive mode or view-only mode via UI
in the Settings -> Server -> Security panel choose 'Only allow connections in view-only mode'

Otherwise you can forbid users to interact with the desktop once connected via configuration by setting in server.cfg:
PhysicalDesktopMode 0

To allow full interaction instead, ensure to have:
PhysicalDesktopMode 2

A further setting allows instead the connected user to interact with the desktop except for resize operations:
PhysicalDesktopMode 1

Others

Always require that a user is actually present in front of the system and accepts the connection
Set in server.cfg:
EnableScreenSharingMode 1
This overrides more permissive settings set in keys LoginScreenAccess, ScreenSharingOwnerAccess and PhysicalDesktopAccessNoAcceptance.

Let the desktop owner access the remote physical desktop also when screen sharing is disabled
Set in server.cfg:
ScreenSharingOwnerAccess 1

Override user's setting to disable 'Desktop shared'
If the user set 'Desktop not shared' from the !M monitor menu of the server, it's still possible to re-enable it via command line.

Execute from a terminal:

$ sudo /etc/NX/nxserver --useredit USERNAME --screen-sharing yes

13.5. Disabling Physical Desktop Sharing

To completely disable connections to the physical desktop, set:
PhysicalDesktopAccess none
In this way, nobody will be able to connect by NoMachine to the physical desktop of this server host.

13.6. Screen Blanking and Automatic Lock of the Physical Screen

NoMachine servers support the screen blanking feature: when active, the local user will see a black screen on the physical monitor while somebody is connected from remote to the physical desktop. Operations made on the physical screen are not shown and the local user cannot interact with the desktop until the remote user logs-out. Control is given back to the local user once the remote user has logged off. Screen blanking is available for physical hosts, it is not supported on virtual machines since it has effect on the physical monitor.

You can activate the screen blanking feature on the server host machine
via the User Interface:
in the Settings -> Server -> Security panel select the 'Blank the physical screen when somebody connects' option.

Otherwise in the node configuration file.
Uncomment and set:
EnableScreenBlanking 1

To disable the screen blanking, set:
EnableScreenBlanking 0

In both cases then restart the server to make this change effective:

$ sudo /etc/NX/nxserver --restart

The screen blanking feature can be used in conjunction with the automatic lock of the remote screen. Even if the user didn't lock the screen before disconnecting from NoMachine, as soon as the screen is unblanked, the system lock screen will be activated automatically to keep the remote desktop protected even when the computer is running unattended.

You can enable the automatic remote screen lock from the User Interface
In Settings -> Server -> Security panel select the 'Lock the physical screen on disconnect' option

or in the server configuration file, server.cfg.
Uncomment and set:
EnableLockScreen 1

To disable the automatic screen lock, set:
EnableLockScreen 0

Then restart the server to make this change effective:

$ sudo /etc/NX/nxserver --restart

14. Device Sharing, Copy&Paste and File Transfer

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The Enterprise Terminal Server Node allows users to access and share their devices and resources from local to remote and vice-versa. Disks, printers, USB devices and more can be connected inside the session to easily access them from both client and server side. At present device sharing is not available with web sessions.

Two-way copy and paste is fully supported. In Web sessions the NoMachine virtual clipboard provides for copying text from/to the session running in the browser and the local computer.

Download/upload files from the session to the local computer and vice-versa is also fully supported in client and web sessions, as well as drag and drop of a file from remote to local and from local to remote.

By default device sharing, copy&paste and file transfer are always permitted. You can however completely disable any of these services or disable it only partially, for example to prevent users from sharing their local printer in the NoMachine session but permitting them to use the remote printer.

Limiting or forbidding device sharing, copy and paste and file transfer can be done on the Enteprise Terminal Server by means of profile rules. Please refer to the Enterprise Terminal Server or Enterprise Terminal Server Cluster guide, section 'Installation', here: https://www.nomachine.com/all-documents

15. Multimedia and Session Recording

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At the moment audio support in NoMachine sessions relies on PulseAudio or Alsa. For those systems not providing PulseAudio by default, it's advisable to install it manually. Work is in progress to add support also for PipeWire Sound Server. Users can record the NoMachine session or the desktop and save the recordings on their devices. Administrators can activate the automatic recording of a session and store the recordings on the server host (see the related paragraph).

15.1. Supporting Audio and Microphone

On Linux, NoMachine audio framework is integrated with PulseAudio sound server. If PulseAudio is not available on the system, NoMachine is able to use ALSA (Advanced Linux Sound Architecture). This is automatically managed by the NoMachine server so that multimedia support can work out of the box without the need for any configuration. If both PulseAudio and Alsa are available, the administrator might want to configure the node to use one or the other.

Disabling or Setting Audio Support
To disable audio and microphone support, uncomment and set the AudioInterface key to 'disabled' in the node configuration file:
AudioInterface disabled

On Linux it is possible to define whether PulseAudio Server or ALSA has to be used by setting AudioInterface key to 'pulseaudio' or 'alsa' respectively. For example:
AudioInterface pulseaudio

15.2. Recording your Screen

NoMachine can video-record all activity made inside the session or on the local desktop. To start the recording of the session, users should open the NoMachine menu inside the session (ctrl+alt+0) and click on the 'Recording' button icon to access the Recording panel. From this panel it's possible to open the recording bar, change audio and video quality and open the recording directory to access all recorded files. Session recording is not available with sessions on the web.

To record activity made on the desktop, start the recording from the !M icon menu in the system tray of the server host and show the Recording bar from there. Desktop activities can be registered on the physical desktop without the need to be connected by NoMachine.

Recorded files

NoMachine videos are recorded into the new NXR file format which uses the MKV format (Matroska), widely used and supported by the major video players which should be able to play such NXR files without requiring transcoding.

Playback of NoMachine recording files is possible with, for example, Windows Media Player on Windows and with VLC for Windows, Linux and also macOS.

The exception is Apple's Quicktime for macOS. QuickTime doesn't support the MKV format. If using VLC is not an option, it's also possible to install the Perian plugin for Quicktime available at https://www.perian.org/.

Recorded files are saved by default on the user's device in the NoMachine directory under the 'Documents' directory.

Disabling session recording
To prevent users from recording their session activities, edit the node configuration to set:
EnableSessionRecording 0

Disabling desktop recording
To prevent users from recording desktop activities, even when physically logged into the Enterprise Terminal Server host, edit the node configuration to set:
EnableLocalRecording 0

15.3. Automatic Screen Recording

The automatic recording of the session at session startup is disabled by default.

To enable it, execute in a terminal:

$ sudo /etc/NX/nxserver --recording yes

The automatic screen recording applies to both connections to the physical display and virtual desktops.

You can also define the percentage of session to be recorded by specifying the '--percentage PERCENTAGE' parameter or activate the recording for a specific user only or group of users by means respectively of: '--user ' and '--group '.

16. Profiles

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A profile is defined by a set of rules which restrict the default behavior. For example you can create rules to disable copy&paste, or limit device sharing etc ... Rules can be set:
a) for all users (as an alternative, the same result can be achieved via configuration files)
b) for specific user(s) only
c) for system groups of users
d) for NoMachine groups of users
e) for nodes

Profile rules must be created on the Enterprise Terminal Server or Enterprise Terminal Server Cluster.

17. Automatic Updates

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The Terminal Server Node, as well as the other NoMachine client and server products, periodically checks NoMachine repositories (by default every two days) to verify if updates are available and will prompt a dialog informing the user that a new version is available.

It will never automatically update the current installation. Also the download in background of a new software version will not lead to an automatic update of the current installation.

A separate guide which deals specifically with all the possible options for the automatic software updates is available on the web site in this section:

https://www.nomachine.com/all-documents

It's recommended to keep version of the Enterprise Terminal Server Node and of the Enterprise Terminal Server or Enterprise Terminal Server Cluster always aligned.

18. Logging Facilities

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To retrieve logs by using the NoMachine tools, please refer to guides available in the Configuration section at: https://www.nomachine.com/all-documents.

When debug mode is enabled, server logs may increase consistently. It's suggested to keep debug level only for the time necessary to reproduce the problem and collect logs.

18.1. Enabling NoMachine Log Rotation

Once activated, in the default configuration, logs are rotated once per month when they exceed 100MB. If not otherwise specified, NoMachine preserves up to seven rotated files and deletes the oldest ones.

Rotated logs are saved in the /usr/NX/var/log/logrotate directory.

Command to activate log rotation is:

$ sudo /etc/NX/nxserver --logrotateadd OPTION

OPTION can be any of the following:
--rotate VALUE, specify the maximum number of rotated files to be preserved in the logrotate directory. When this number is exceeded, the oldest files are deleted.
--time-interval TIME, specify the frequency of log rotation. Frequency can be specified in seconds or by using the 'Daily', 'Weekly', 'Monthly', or 'Yearly' keyword. Rotate logs when the interval of time and the minimum log size is reached.
--min-size VALUE, specify the minimum file size for rotating logs according to the given interval of time. If the minimum size is not reached, logs are not rotated. Value is by default in kilobytes, add M or G to set it in megabytes or gigabytes respectively.
--size VALUE, specify the minimum file size for applying log rotation as soon as the file size is reached, regardless of the frequency set for log rotation.
--compress yes|no, by default each log file is compressed as a gz archive, use '--compress no' to not compress it.
--destination PATH, provide an alternative path where to store the rotated files. If OPTION is not specified, the default settings will be applied.

By default, log rotation is applied to all NoMachine log files. It's however possible to specify which log file should be under log rotation:

$ sudo /etc/NX/nxserver --logrotateadd LOG OPTIONS

LOG can be any of these files:
server.log
daemon.log
webrunner.log
htd.log

If OPTION is not specified, the default settings will be applied.

Other commands to manage log rotation

List current settings for log rotation:

$ sudo /etc/NX/nxserver --logrotatelist

Edit parameters set for log rotation:

$ sudo /etc/NX/nxserver --logrotateedit LOG OPTION

Delete all settings for log rotation:

$ sudo /etc/NX/nxserver --logrotatedel

Delete log rotation settings for a specific log file:

$ sudo /etc/NX/nxserver --logrotatedel LOG

It's possible to force log rotation at any moment. This doesn't require enabling it.
This can be helpful for example to debug a problem easily reproducible:
- clean up logs with 'nxserver --logrotate'
- activate the debug log level with 'nxserver --debug --enable all'
- reproduce the problem
- collect logs with 'nxserver --debug --collect'
- and finally restore informational log level with 'nxserver --debug --disable all'.

To apply log rotation to all files or to a given log only:

$ sudo /etc/NX/nxserver --logrotate LOG OPTIONS

OPTION can be any in this case any of the following options:
--compress yes|no, by default the log file is compressed as gz archive, use '--compress no' to not compress it.
--destination PATH, provide an alternative path where to store the rotated files.

18.2. Using the System Logging Facilities

It's possible to configure nxserver, nxwebplayer/nxclient and nxnode programs to log to the system log file. Edit the server.cfg and node.cfg files, uncomment and set:

EnableSyslogSupport 1

Then restart the server and all services to make the change effective:

$ sudo /etc/NX/nxserver --restart

18.3. Built-in Audit Tools (Automatic Recording and File Transfer Logging)

Automatic recording

NoMachine has the possibility to enable the automatic recording of the user's session. Users experience inside the session can be captured totally or partially (recording of a given percentage of session) and saved as .nxr files on the server host, to be replayed at any moment by using NoMachine client or whichever other media player supporting H.264 codec.

The automatic recording of the session at session startup is disabled by default.

To enable it on Linux and macOS:

$ sudo /etc/NX/nxserver --recording yes

On Windows:

> %ALLUSERSPROFILE%\NoMachine\nxserver\nxserver.exe   --recording yes

You can also define the percentage of session to be recorded by specifying the '--percentage PERCENTAGE' parameter or activate the recording for a specific user only or group of users by means respectively of: '--user ' and '--group '.

Recorded files are saved by default in:
%PROGRAMDATA%/NoMachine/var/recording on Windows
/Library/Application Support/NoMachine/var/recording on macOS
/usr/NX/var/recording/ on Linux.

To store them in a different place, provide a path for the NXRecordingDirectory key in the node configuration.

By default the connecting user can accept or refuse to allow NoMachine to automatically record his/her session. It's possible to change this behaviour by setting in the server configuration an appropriate value for the AutomaticRecordingAuthorization key.

Inform the user that his/her session will be recorded, the user cannot refuse that:
AutomaticRecordingAuthorization 0

The user can accept or refuse to allow NoMachine to record his/her session but in this last case the session will be terminated or disconnected in case of a virtual desktop:
AutomaticRecordingAuthorization 2

The connecting user can accept or refuse to allow NoMachine to record his/her session:
AutomaticRecordingAuthorization 1

File transfer logging

It's possible to enable the logging of file transfer operations to the server log file. Such logs contain the word 'Audit' for being easily retrieved.

File transfer operations are not logged by default. To enable the audit, set in the node configuration:

EnableAuditlogs 1

To disable the audit, set:

EnableAuditlogs 0

 

19. Setting-up Centralized Access to Multiple Servers

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If you own multiple installations of Terminal Server, you may need to provide your users with a single point of access to all of these servers. This can be done by installing any of the NoMachine Cloud Server products on a dedicated host and add each Terminal Server to it.

The available products are conceived to fit different business sizes, even from a pricing perspective and are: Small Business Cloud Server, Cloud Server, Enterprise Cloud Server and Enterprise Cloud Server Cluster. For simplicity, we refer below to 'Cloud Server', which can be any of those products.

19.1. Setting-up Central Access to the Server

Enterprise Terminal Server Nodes accept connections only through the Enteprise Terminal Server and cannot be added as nodes of a Cloud Server. It's possible instead to add the Enterprise Terminal Server to an Enterprise Cloud Server Cluster or an Enterprise Cloud Server.