VNC viewer connection aborted


I've just installed RealVNC enterprise edition 4.2.5 on a Win 2003 server. When trying to connect from another windows box, I have no problem, but when I try to connect from a linux box (also running v4.2.5 enterprise edition), vncviewer gives the following and fails to connect:

VNC Viewer Enterprise Edition E4.2.5 for X - built May 16 2006 17:37:03
Copyright (C) 2002-2006 RealVNC Ltd.
See for information on VNC.

Tue Jun 13 11:22:09 2006
 TcpSocket:   connected to
 CConn:       Connected to host ServerX port 5900
 CConn:       Encryption set to 'Server'
 CConnection: Server supports RFB protocol version 4.0
 CConnection: Using RFB protocol version 4.0

My linux platform is Ubuntu Dapper Drake 6.06
The RealVNC package was installed from the RPM distribution following the instructions in the RealVNC documentation.

As a matter of interest, running vnclicense produces and aborted message as well when trying to use -add to add the license key.
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Ok the Java client works & connects to the server fine
So possibilities of source:
1) Linux OS problem
2) Linux VNC client sending out incompatible data
3) Windows VNC server not deciphering data correctly

Sorry, I can't help further than to suggest it may be a VNC bug. Its odd that even AT THE REALVNC SITE, there is no answer to the SAME QUESTION. (see link given earlier). Even the sole EE link (above) that I could find on all of EE, didn't resolve the issue.

Just because it's a trial, doesn't mean that the company won't accept bug reports. Many are happy to hear of bugs. I've received excellent support from some even without the need to confirm registration, notable ones being,, and, while many others have at least responded to my suggestions/bug reports.

Can't hurt to send them email, see what they say.

RealVNC can be very difficult to set up and mantain properly through cross platform systems. The problem could be through the outgoing request through the linux box settings. I would reccomend to sites like .
They have a free 30 day trial you can try, I've used it on plenty of occasions and if this is a time sensitive matter I would say give it a shot.
  ~ Best of luck!
Just a guess: "RFB protocol" may be the trouble on either the Win 2003 side, or the Linux side. Make sure the protocol versions etc. are the same?
Another guess: Is the encryption being set to "Server", correct or not?
Free Tool: Port Scanner

Check which ports are open to the outside world. Helps make sure that your firewall rules are working as intended.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

stoncr00Author Commented:
Encryption on the server is disabled. The client is set to use the server specified encryption mode.
stoncr00Author Commented:
btw the RFB (remote frame buffer) protocol is the one and only one that I think VNC can use. Since both client and server are the same version, I have to assume that the RFB protocol versions match. I don't know of anywhere in the VNC server config where on can select the RFB protocol version used.
Someone else may be trying to log in the same time you are... Your Windows login may be connected when your Linux is connected causing a hiccup???
Try connecting without a viewer (through the browser, port 5800), or using another VNC viewer (ultravnc, xf4vnc, tightvnc...)
A read through this may bring up ideas:

I've used VNC on Windows, and I can connect to server with Internet Explorer on the client machine - no separate viewer needed. Question is, can a Linux machine's web browser do the same? Try with the free version of RealVNC (or TightVNC etc.) for windows -- then connect from the Linux machine. If it works, then the enterprise edition is the problem. If it doesn't work, then something seems wrong in the communication between Linux & windows.

If you bought the VNC, why not e-mail for support? I'm sure they would not want to sell buggy software & would welcome input to fix bugs or enhance the product.

Problem is listed at these two links but is unresolved:     Linux->windows problem     Linux: VNCViewer on Linux

Another hint is in the following which mentions "aborted":    xvnc(1): X VNC server - Linux man page
-rfbwait time, -ClientWaitTimeMillis time
Time in milliseconds to wait for a viewer which is blocking Xvnc. This is necessary because Xvnc is single-threaded and sometimes blocks until the viewer has finished sending or receiving a message - note that this does not mean an update will be aborted after this time. Default is 20000 (20 seconds).
stoncr00Author Commented:
I have VNC session sharing enabled on the server side. I am also the sole individual with remote access to the Window box - we're a small company - so there isn't anyone else accessing it. Please note my comment in the original posting about vnclicense. When running "vnclicense -add <licensekey>" I get one line of output - "Aborted" and no further error messages. I believe that this issue with the licensing tool is related to the issue with the viewer.
Why not try to connect through the browser instead of the viewer? Etc. We need to narrow down the source of the problem by sorting through what currently will & wont work.
From your web browser in Linux, type in:
You would of course first have to, on the Windows side, enable connections via a web browser. And forward port 5800 in the router/firewall setup.
If that doesn't work, see if the free edition of realvnc, ultravnc, and/or tightvnc will allow the linux machine to connect. If  that works, then the problem is with the enterprise edition. If doesn't work then trouble is possibly at the Linux side...

Enterprise Edition is purchased, right? The company should provide support ...
stoncr00Author Commented:
Already tried that and can connect using the java client. Since the java client is downloaded from the server side, I don't think the logic about where the problem lies really applies. I am specifically interested in the ent.edition because of the administration/distribution tool that can be used with it, as well as the single sign on NT authentication and encryption, so the free clients don't really satisfy my requirments.

I'm trialling enterprise edition so I definitely won't be bothering to purchase if I can't get it working in the first place. There is no free support available from VNC apart from their knowledge base (which has nothing about this problem). Even Google turns up zip.

That's why I forked out for experts exchange - I thought maybe someone here would have a solution :)
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