Using VNC

NOTE: VNC is deprecated. For all remote desktop access, we ask that you use X2Go (found here).

VNC is a system for interacting with a computer display remotely, over a network. This technology was developed by AT&T Laboratories, and is now available for free over the internet (distributed under the GNU General Public License. Visit the RealVNC website for more information or follow the links below for information about the easiest way to use VNC on your computer.

Remote access to the Comp Sci Unix system with a full graphical display. This will give you access to a full graphical shell like the ones available on the Asprey lab computers, although it is somewhat slower than SSH. This will allow you to use programs like Netbeans and other IDE’s from the comfort of your home.

If you are a member of the Vassar Computer Science Department as a student or faculty member, you have access to a graphical Unix system by visiting the Asprey Advanced Computation Laboratory or a remote textual login using ssh. By using VNC, you can access the same graphical Unix system that you find in the lab, over the network.

The instructions for each operating system follow these general steps:


Download and install a secure shell client (if not already available).

Download and install a VNC client.


Forward a port over a secure connection.

Connect using your VNC client.

Step-by-step directions are available by operating system:


Macintosh OS X

Linux (or other Unix-like OS)

Speeding it up

When working remotely there are a number of reasons that your vnc session can feel sluggish. However, there are some simple things to try that can speed up your vnc session. You may have to try a few different things before you find the combination that gives you the best performance. If you want to try and speed up your vnc session, please check out our speed_tips page.

General notes:

An Emacs display problem has been reported. Emacs is looking for a bitmaped font that is not available over the vnc connection. for a bitmaped font that is not available over the vnc connection. This problem can be delt with by telling emacs what font to use. Try:

emacs -fn 8x13

The values 7×13, 9×15 and 10×20 will also work. Additionaly, once in emacs you can get a menu of fonts either with [shift]+[mouse button one (usually the left button)], from the pull down menus with 'option' - 'mule' - 'Set font/fontset' or with M-x set-default-font [return] [tab].

Instructions are available for resolution changing the resolution of the VNC client display.

We are tricking the VNC client by making it look for its connection on the local computer instead of the VNC server. This allows us to create a separate, and secure, connection from our computer to the server. However, some VNC clients do not use compession by default when connecting locally. If you are using a client other than the ones described by these directions, it is a good idea to see if you need to explicitly turning on compression.

Within a VNC session you can press F8 to get a list of VNC commands.

We can not provide VNC instructions for versions of the Mac OS prior to Mac OS X because we have not found programs providing secure port forwarding.

The best place to find out about VNC is the RealVNC website, where there's documentation and troubleshooting information.

Having problems?

Contact the System Administrator, Make sure to include your operating system, which steps you took, and at what point in the instructions things seemed to go wrong.