User manual

connection is a standard SSL (Secure Socket Layer) encrypted link that encrypts all data

from the session, including the actual video pictures.

Because Java is considered a “safe” programming language, the Java VNC client has

some limitations. Certain special keystrokes cannot be sent, such as Scroll Lock on the

keyboard.

This client software requires the use of Java 2 (JRE 1.4) to enable features like wheel

mouse support. Sun Microsystems’s Java site, www.java.com, is an excellent resource to

ensure your browser and operating system is up-to-date.

Native VNC Client

This system implements the VNC protocol, so any off the shelf VNC client can be used.

There are over 17 different VNC clients available and they should all work with this system.

This system automatically detects and makes use of certain extensions to the basic RFB

protocol that is provided by the better VNC clients.

The best client currently is TightVNC (www.tightvnc.com). Binaries are available for

Windows, Linux, MacOS and many versions of Unix. Source code for all clients is available

there too. This version of VNC is being actively developed. The authoritative version of

VNC is available from RealVNC (www.realvnc.com). This source base is the original

version of VNC, maintained by the original developers of the standard. For a commercial,

supported version of VNC, you should consider TridiaVNC (www.tridiavnc.com). Their

version of VNC is a superset of TightVNC and contains a number of enhancements for use

in a larger corporate environment.

NOTE: Some native VNC clients may require a flag or setting indicating they should use

BGR233 encoding by default. If this flag is not set, you may see a garbled picture and the

client will fail. The Unix versions of VNC require the flag -bgr233. For examples on using

this flag, review the commands in the following section.

SSH Tunnel (with Native VNC client)

If you are using openssh, here is the appropriate Unix command to use, based on the

default settings on a machine at 10.0.0.34:

ssh -f -l admin -L 15900:127.0.0.1:5900 10.0.0.34 sleep 60

vncviewer -bgr233 127.0.0.1::15900

Notes : y A copy of these commands, with appropriate values filled in for your current

system setting, is provided in the on-line help page. This allows you to “cut-and-

paste” the required commands accordingly.

y You have 60 seconds to type the second command before the SSH connection

will be terminated.

y The port number “15900” is arbitrary in the above example and can be any

number (1025...65535). It is the port number used on your client machine to

connect your local SSH instance with the VNC client. If you want to tunnel two or

more systems, you will need to use a unique number for each instance on the

same SSH client machine.

y Some Unix versions of the VNC client have integrated SSH tunneling support.

Some clients require your local user id to be the same as the userid on the

system. Use a command like this:

vncviewer -bgr233 -tunnel 10.0.0.34:22