Installing the FreeNX server on Ubuntu Karmic (9.10)

Karmic introduces the add-apt-repository command that simplifies most of the work of adding a third party repository.

1. Open your terminal

   Applications->Accessories->Terminal

   and type in this command

   sudo add-apt-repository ppa:freenx-team

   • NOTE: If you do not have add-apt-repository installed add the following

       sudo apt-get install python-software-properties

2. Then Update Apt

   sudo apt-get update

3. At this point, the repository is added and apt is updated, then install the freenx package (using Aptitude to install extra needed packages).

   sudo aptitude install freenx

4. Now use nxsetup to install necessary files and create the special user "nx"

   sudo /usr/lib/nx/nxsetup --install 

Installing the FreeNX server on older Ubuntu Versions

This Instructions are for older Ubuntu versions. FreeNX is not included in Ubuntu, so we'll add it from the FreeNX Team PPA.

Add this repository using the Third-Party Sources Tab in Software Sources. When it asks, Reload the information about available software. Now you can see and install the freenx package in Synaptic Package Manager.

You must edit the configuration files and install by hand:

1. Open your apt sources list

   gksudo gedit /etc/apt/sources.list

   and append the two lines for the repository

   deb http://ppa.launchpad.net/freenx-team/ppa/ubuntu VERSION main
   deb-src http://ppa.launchpad.net/freenx-team/ppa/ubuntu VERSION main

   where VERSION can be: dapper, hardy, intrepid or jaunty. More information can be found at FreeNX Team PPA.

2. Save and then close.

   To add the public key of FreeNX PPA run:

   sudo apt-key adv --recv-keys --keyserver keyserver.ubuntu.com 2a8e3034d018a4ce

3. Then Update Apt

   sudo apt-get update

4. After you add the repository, then install the freenx package (using Aptitude to install extra needed packages).

   sudo aptitude install freenx

5. Now use nxsetup to install necessary files and create the special user "nx"

   sudo /usr/lib/nx/nxsetup --install 

Installing the NX Client

The official NX client is not in the Ubuntu repositories.

You should be able to access your Ubuntu box from any Windows or Linux box using the free client from NoMachine's website. You can also embed your NX Server in a webpage by installing the Nomachine Web Companion and the Apache webserver.

Now you can execute the installed client using the following command:

/usr/NX/bin/nxclient &

Or by looking it up in the menu

This will start the NX client in a GUI, and step you through getting connected to the FreeNX server, and you will be on your way! [Note: If you are behind a firewall you may need to enable SSL encryption under the Advanced configuration tab - JeremySchroeder]

Installing QTNX (Opensource client)

sudo apt-get install qtnx

Miscellany

NX Server Free Edition

NX Server Free Edition provided by NoMachine is not related to FreeNX. NXSFE has a limit of 2 sessions per server. FreeNX doesn't have this limit.

FreeNX on PowerPC

There are no precompiled binaries of FreeNX on this platform (Launchpad PPA doesn't provide support), so FreeNX have to be compiled from source. Sources can be found at the FreeNX Team PPA.

These steps will build FreeNX from source (you need to add the deb-src repository):

1. Create a directory to hold the FreeNX source, and cd into it.

   mkdir freenxSource; cd freenxSource

2. Build the freenx packages and install related packages.

   sudo apt-get build-dep nx freenx
   apt-get -b source nx freenx

   This will download the source tarballs and build the freenx packages (*.deb) in the current directory.

3. Install the FreeNX packages.

   sudo dpkg -i *.deb

4. If dpkg complains about missing packages, let apt fix it

   sudo apt-get -f install
   sudo dpkg -i *.deb

How to start/stop FreeNX

The FreeNX server is not a service but uses ssh. The following command will stop the FreeNX program from accepting connections.

sudo /etc/init.d/freenx-server stop

(Replace stop by start for starting it again)

Configuring SSH port

By default, nxserver uses port 22 for communicating over SSH. On some machines or networks, port 22 may be blocked; some Internet providers block port 22, for instance. Port 22 is also a common target of people trying to crack into a network. To make the SSH server listen on port 8888, you can do the following:

Edit the file /etc/ssh/sshd_config

gksudo gedit /etc/ssh/sshd_config

Find

Port 22

and change it to

Port 8888

You then need to restart SSHD. Try

/etc/init.d/ssh restart

FreeNX should detect the SSHD port, but otherwise: Edit the file /etc/nxserver/node.conf

gksudo gedit /etc/nxserver/node.conf

Find

# The port number where local 'sshd' is listening.
#SSHD_PORT=22

and change it to:

# The port number where local 'sshd' is listening.
SSHD_PORT=8888

That is, change the port number to the one that sshd is listening to, and uncomment the line.

Then edit the file /usr/NX/etc/server.cfg

Find

SSHDPort = "22"

and change it to

SSHDPort = "8888"

then find

SSHDAuthPort = "22"

and change it to

SSHDAuthPort = "8888"

Using custom SSH keys

After installation, FreeNX will use a set of default ssh keys for authentication. This is a security risk, especially on any internet-facing machines, and the default keys should be replaced with your own custom keys.

To change the default keys to your own custom keys - on the machine hosting the freenx-server, run the command:

sudo dpkg-reconfigure freenx-server

This will launch a dialogue that will guide you through the generation of custom keys. On the first page hit 'OK' and on the second page select 'Create new custom keys'

a key file called client.id_dsa.key will be created in: /var/lib/nxserver/home/custom_keys/

Now, we need to transfer the key to the client machine so that it can be imported in the FreeNX client application. First copy the key to your home directory on the server machine:

sudo cp /var/lib/nxserver/home/custom_keys/client.id_dsa.key ~/

Next, copy client.id_dsa.key to your client machine. Ideally you should copy the file securely, for example by running the following command from the client computer:

scp user@freenx-server:~/client.id_dsa.key ~/

which will securely copy the client.id_dsa.key file from the freenx-server computer to your home directory on the client.

If your client is a Windows machine, just copy the key with your preferred method.

In the nx client software you can now import this key.

After you have tested that authentication is working using your custom keys you should then remove the client.id_dsa.key file from your home directories on both the server and client machines.