Getting a graphical login over the internet

Software you will need
Configure the software
Connect and work

SOFTWARE

All the software you need is free. It is not only free, it is also very small: TightVNC viewer (268kB, exe only) and Putty (368kB, exe only). And none of these needs to be installed to run! So not need to run setup.exe on you computer to get connected. So it is just the perfect solution to carry around on a USB stick or even a floppy!

You can also do this with winssh of course...

This document only details the procedure for a Windows to Linux login. You can do just the same from Linux of course.

--> You can not only get a graphical login, the connnection will be secure (encrypted) and compressed. This will be done by using a SSH tunnel

DOWNLOAD

The TightVNC viewer can be downloaded from: http://www.tightvnc.com/download.html
The secure shell (SSH) client PuTTY can be found at: http://www.chiark.greenend.org.uk/~sgtatham/putty/download.html

CONFIGURE

Start PuTTY and create a session with the settings as displayed in the picture below. DO NOT FORGET TO SAVE you session before pressing OPEN!!!! If you don't you will have to enter all the settings again.

You also need to configure at least one SSH Tunnel. Click on 'Tunnels' on the left navigation bar of the PuTTY configuration window. Type the coordinates as displayed below and press ADD. You can create several tunnels as long as they do not conflict with each other.

CONNECT

We assume you will login in using a 800x600 screen with 16bit colors. This means we will login using the SSH tunnel to port 5961.Other settings are possible see on of this page.

To work you need:

Start PuTTY and load you session with the SSH settings (check that the SSH Tunnels are indeed present or this will not work)
Logged in succesfully? Yes, go to 3. No, check the settings and go to 1.
On you machine start vncviewer.exe
In the box next to vnc server type: localhost:61 and click OK
A window opens and offers you a login screen... Yes, start working. No, check whether you have the correct setting for your SSH Tunnels.

DO NOT close the PuTTY windows while working, this would terminate the SSH tunnel and kill you graphical session as well.

EXTRA SETTINGS

TightVNC already uses compression so enabling compression in SSH will not help, on the contrary.
Several resolutions and color depths are available for the graphical logins. A smaller windows with less colors will always be faster, 800x600x16 or 1024x768x16 are working fine over and ADSL connection. When connecting from the VUB campus higher settings _should_ be workable.
A connection using a 1024x768 with 256 is very fast and still acceptable, login to localhost:52 (setup the tunnel first).
It is uselss to take a colordepth that exceeds the one on your local machine. If you use 24bits colors on your machine (for example) it is no use to use VNC to connect to a 32bits colors port (598x ports). You will not see the difference and the speed will be lower.
Below you find a list with the resolution and color depth (first colom) and the port to use in the SSH Tunnel. So if you want a 800x600 screen with 256 colors (8bits) use port 5951 as a "Source port" for the SSH tunnel. The destination, localhost:5951, of the SSH Tunnel is best using the same port (5951) as the source port. Notice that you will have to use localhost:51 when connecting with the vncviewer. The vncviewer automatically adds 5900 to the destination port!!!
```
 640x480x8 5950
 800x600x8 5951
 1024x768x8 5952
 1280x1024x8 5953
 1600x1200x8 5954

 640x480x16 5960
 800x600x16 5961
 1024x768x16 5962
 1280x1024x16 5963
 1600x1200x16 5964

 640x480x24 5970
 800x600x24 5971
 1024x768x24 5972
 1280x1024x24 5973
 1600x1200x24 5974

 640x480x32 5980
 800x600x32 5981
 1024x768x32 5982
 1280x1024x32 5983
 1600x1200x32 5984
```