分类: LINUX
2009-06-29 13:43:14
is a system that allows you to access your desktop from another machine over the Internet. You can use this to login graphically to your desktop from a remote location. One example of its use would be to have a FreeNX server set up on your home computer, and graphically logging in to the home computer from your work computer, using a FreeNX client.
It's Open Source, secure (SSH based), fast and versatile!
Note: Running FreeNX as server on Ubuntu with the free "NX Client for Windows" from on a Windows workstation is working fine.
The Server is the computer you want to connect to. This is the computer where the FreeNX server will need to be installed. The name of the Ubuntu package providing the server is "freenx". For the example used here, the home computer is the server.
The Client is the computer from which you want to be able to access the Server. The name of the Ubuntu package providing the client is "nxclient". For the example used here, the work computer is the client.
Before installing FreeNX server make sure you have SSH set up and is working. You can find the SSH Howto here:
We will be installing the FreeNX server on the Server machine, i.e., the machine that you want to access remotely. In the stated example, this is your computer that is at home.
FreeNX is not included in Ubuntu, so we'll add it from the .
Add this repository using the in Software Sources. When it asks, Reload the information about available software. Now you can see and install the freenx package in .
Alternatively, you can edit the configuration files and install by hand:
Open your apt sources list
gksudo gedit /etc/apt/sources.list
and append the two lines for the repository
deb VERSION main
deb-src VERSION main
where VERSION can be: dapper, hardy, intrepid or jaunty. More information can be found at .
To add the public key of FreeNX PPA run:
sudo apt-key adv --recv-keys --keyserver keyserver.ubuntu.com 2a8e3034d018a4ce
Then Update Apt
sudo apt-get update
After you add the repository, then install the freenx package (using Aptitude to install extra needed packages).
sudo aptitude install freenx
Now use nxsetup to install necessary files and create the special user "nx"
sudo /usr/lib/nx/nxsetup --install
For the paranoid: there is an added security risk involved in using the default keys. If you keep the default keys then everybody will be able to connect to your SSH server as the NX user which is added to your system during the installation. This opens an additional (and unnecessary) opportunity to attack your computer. You could avoid it by using custom SSH keys, as explained later.
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 . 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 - ]
sudo apt-get install qtnx
NX Server Free Edition provided by is not related to FreeNX. NXSFE has a limit of 2 sessions per server. FreeNX doesn't have this limit.
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):
Create a directory to hold the FreeNX source, and cd into it.
mkdir freenxSource; cd freenxSource
Build the freenx packages and install related packages.
sudo apt-get build-dep nx freenxThis will download the source tarballs and build the freenx packages (*.deb) in the current directory.
apt-get -b source nx freenx
Install the FreeNX packages.
sudo dpkg -i *.deb
If dpkg complains about missing packages, let apt fix it
sudo apt-get -f install
sudo dpkg -i *.deb
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 stop
(Replace stop by start for starting it again)
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.
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/
First copy the key to your home directory:
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.
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.
An up-to-date repository from the FreeNX Team, for Ubuntu 8.04 (Hardy), 8.10 (Intrepid) or 9.04 (Jaunty)
FreeNX old repository
How to remote desktop using SSH and FreeNX - OpenGL Seveas Repositories
You can also have a look at the article about installing the
For those who wan't to have freenx supported in krfb, krdc, log into bugs.kde.org, and add a comment and vote for the following bugs (wishlist) :
: nxserver support in krfb
:nx support in krdc (client), it seems that work is already in progress, and there only a few problems left.