There are currently (3) basic methods for getting a remote control GUI on a Linux server (like we do with Remote Desktop for Windows servers):

1) X-Windows over TCP/IP

All GUI operations on Unix/Linux are handled by the X-Windows sub-system. Window interfaces like KDE, Gnome, and others are merely layered on top of the X sub-system. One of the useful things about X is that any window can be forwarded over TCP/IP to any other X server. So you could run an application on the linux server, but display the output window on your PC (as long as you run a local X server program).

The downside of all this is that accessing remote servers requires the use of SSH port forwarding, and a bit of arcane magic. It's nowhere near as clean of a solution as RDP (Terminal Services). But it can be ultra-secure (by using SSH keys) and it works fairly well across the WAN.

2) VNC

VNC is a screen-scraper solution for GUI desktops, very similar to the old pcAnywhere and e/pop solutions that we used to use.

The downsides of VNC are:
- security is non-existent in the base spec
- different VNC server use different encryptions
- authentication tends to be done via plain text passwords
- rather slow across the WAN

3) NX/FreeNX

A company called NoMachines came out with a different solution called "NX". NX is a protocol that is very similar to RDP and the client works rather similar to Remote Desktop. You used to have to pay for the product, but over the years, they've opened up the source code. So now there are (3) different server implementations (NX, FreeNX, and another) and you can download the NX client from NoMachines for free.

The big advantage here is that security is better and performance is better over slow WAN links.

Labels: 2008, FreeNX, Linux, NX, VNC, X11

Installing UltraVNC (see also "UltraVNC Installation")

1. Download UltraVNC for MS Windows
   
2. Run the setup program (currently this is: UltraVNC-100-RC203-Setup.exe)
   
3. Accept the license agreement and read the Information screen
   
4. Use the default install destination location
   
5. Choose "Complete Install"
   
6. Use the default Start Menu Folder
   
7. Turn ON "Register Ultr@VNC Server as system service"
   
8. Turn ON "Start or restart Ultr@VNC service"
   
9. Turn OFF the (3) options that create desktop icons
   
10. Turn ON "Associated .vnc files with Ultr@VNC Viewer"
    
11. Click "Install" to start the installation.
    

WinVNC: Default Local System Properties (see "configuration for details)

1. Turn OFF "Enable JavaViewer"
   
2. Turn ON "Display Query Window", Set the timeout to 60 seconds, with "Accept" as the default action.
   
3. Under "Multi viewer connections", CHANGE to "Keep existing connections"
   
4. Under "Authentication", set a secure default password
   
5. Under "Authentication", turn ON "Require MS Logon", turn ON "New MS Logon"
   
6. Click on "Configure MS Logon Groups", Add, enter "Administrators" (note the plural) and click "OK". Grant that group full control and click "OK" to close the UltraVNC Security Editor window.
   
7. Most other options can be left "as is"
   

AES Encryption plugin (a.k.a. DSM)

1. Download the AESV2 Plugin (currently: AESV2Plugin100.zip)
   
2. Extract the .DSM file to the program folder where you installed UltraVNC (usually: C:\Program Files\UltraVNC), see "DSM quick start" for more information.
   
3. Re-open the "Default Local System Properties" window for the UltraVNC server (Start -> UltraVNC -> UltraVNC Server -> Show Default Settings). Alternately, start up the service helper systray app (Run Service Helper) and go to "Admin Properties")
   
4. Under "DSM Plugin", turn ON the "Use:" checkbox and select "AESV2Plugin.dsm" from the list.
   
5. Click "OK"
   

Labels: 2007, ServerAdministration, UltraVNC, VNC

Various links about VNC

Virtual Network Computing (VNC) - Wikipedia entry about VNC.

Taking your desktop virtual with VNC by Tim Waugh

VNC FAQ-o-Matic

Making VNC more secure using SSH

Free and Easy Remote Access with VNC Reverse Connections

Geek to Live: Secure VNC with Hamachi

Secure VNC with two-factor authentication

Labels: 2007, ServerAdministration, VNC

I haven't tried this yet, but there are times when it could come in handy.

Centos 5 vnc remote installation

Post details: Upgrading to CentOS4, over a remote vnc connection

I figured it was possible, I just hadn't looked.

Labels: 2007, CentOS5, VNC