This page is here to help you use and understand VNC, an alternative to
telnet access to your account on Johnny.
What's VNC?
Without getting into technical details, VNC allows you to connect to a
computer running VNC server (such as Johnny) and access your data in a
graphical format. Basically you can use your own keyboard and mouse to
control another's computer (with proper credentials, namely a password).
What you see on your screen is an exact replica of the server’s computer
screen. This is very helpful, especially when working with files, because
who can really remember all those Unix commands, anyway? Using your mouse
is so much easier!
Cool! How do I start?
Once you are logged into your account through telnet, simply type the
command vncserver. If this is your first time running, it will
ask for a password and to verify the password. You can use the same
password you have for Johnny if you wish. Finally, make sure to note the
desktop number denoted by: New X desktop is johnny.sas.upenn.edu:#. Mine,
for instance, is 3. Once you run the program you can safely close the
telnet session.
And then what? How do I see my work?
Basically, while vncserver is running, you have an open connection to your
account, protected by the password you inputted earlier. The open
connection is denoted by a port number. Different internet protocols use
different ports: telnet commonly uses port 21, ftp uses 22, http (web)
uses 80. VNC, by default, uses 58##, where ## is the desktop number from
before. The vncclient program (see below to download) connects to Johnny
at this port number (see Help with Telnet and
FTP for more information about port numbers).
The program is found under "Start Menu/Programs/VNC/Run VNCviewer. My VNC
server, in my example, is johnny.sas.upenn.edu:3 -- the server name and
the desktop number in my case. Everyone will be given a unique desktop
number, because multiple vncserver instances will be running at the same
time. The next person to run vncserver will get desktop number 4, the
next 5, etc.
How do I quit VNC?
Easy. Close the window. But remember that in the background the server
is still running! If you want to shutdown the server, run telnet and type
vncserver -kill :#, again with # representing the
desktop
number. The server is now closed, and you can safely quit the telnet
application.
Tips
If you don't have the VNC viewer handy, you can go to
http://johnny.sas.upenn.edu:58##, where ## denoted the desktop number (3
being 03, etc). This runs a Java version of the server, but it is much
slower! Also, it’s a good idea to kill the server if you’re not going to
use it for a while.
Links