vncserver & xvncviewer question

[Ice9]

I've got a situation here at home where my kids have their own pc in their room on the upper floor.
Whenever they have a problem they yell after me, and because I tend to be lazy I installed vncserver on their workstation.

Everything works fine, I can start a server on any given display and connect to it using the same display number.
However, for educational purposes I'd like them to see what I'm actually doing and they don't because their active X session is on display :0 and I can only launch/connect to a vncserver from display :1 on.

When I don't specify a display number it launches on :1 and when I try to do
vncserver :0
I get

Code: Select all

0 is not taken because of /tmp/.X0-lock
Remove this file if there is no X server WS3:0
A VNC server is already running as :0


Is there any way for me to actually connect to the desktop they use with vnc and show them how I solve their problems?
I used to do that a couple of years ago but then I was connecting to Windows boxen with my linux box, now everyone around here runs Debian - except for my wife who runs FC3 and I can't figure out how to do it .....

[Void Main]

In Fedora/GNOME VNC is actually built in so you can remote control someone's desktop. I think it will work for GNOME on any OS though. On Fedora it's on the menu Desktop->Preferences->RemoteDesktop to configure. The program that is actually called from that menu item is "vino-preferences" which is part of the "vino" RPM which is described this way:

Code: Select all

Name        : vino                         Relocations: (not relocatable)
Version     : 2.10.0                            Vendor: Red Hat, Inc.
Release     : 4.1                           Build Date: Fri 30 Sep 2005 05:09:41 AM CDT
Install Date: Mon 03 Oct 2005 07:37:09 PM CDT      Build Host: tweety.build.redhat.com
Group       : User Interface/Desktops       Source RPM: vino-2.10.0-4.1.src.rpm
Size        : 1000311                          License: GPL
Signature   : DSA/SHA1, Fri 30 Sep 2005 08:56:58 AM CDT, Key ID b44269d04f2a6fd2Packager    : Red Hat, Inc. <http://bugzilla.redhat.com/bugzilla>
URL         : http://www.gnome.org
Summary     : A remote desktop system for GNOME
Description :
Vino is a VNC server for GNOME. It allows remote users to
connect to a running GNOME session using VNC.


It works really well. I'm sure all you have to do is install vino, if you use GNOME that is. I think KDE has something similar though.

[Master of Reality]

KDE uses Kfrb for desktop sharing, i think it is through VNC as well

[Ice9]

Yes there is something similar for kde, krfb but I would've preferred a simple setup with vnc.

What I have to do now is configure the remote desktop service from kde to announce itself permanently on the network and to allow uninvited connections to take over the desktop, where with vnc I could start a server from an ssh session and connect to it with the viewer, and then kill the server when I have finished.

Edit: Oops, I should reload my browser before posting an answer.
Thanks MoR, krfb was what I have been using until now.

[Void Main]

But can't you password protect it and only allow connections from specific IP addresses (iptables)? I do this with GNOME. But to answer your question, no you can not do that with vncserver (unless something has changed that I am not aware of).

[Ice9]

an't you password protect it

Yes I can and I have, but it's one service more to run in the background thus one more risk for vulnerabilities.
And I don't run iptables on my workstations anymore, I'm behind a firewall/router so that would be a "no" for the allowing of unique IP addresses.

But ok, if there's no other way I guess I'm gonna have to keep using krfb
Thanks anyway guys!

[Tux]

Try RealVNC:

http://www.realvnc.com/products/free/4.1/x0.html

[Master of Reality]

if your behind a firewall shouldnt it be no problem to run kfrb password protected?

[Void Main]

an't you password protect it

Yes I can and I have, but it's one service more to run in the background thus one more risk for vulnerabilities.
And I don't run iptables on my workstations anymore, I'm behind a firewall/router so that would be a "no" for the allowing of unique IP addresses.

But ok, if there's no other way I guess I'm gonna have to keep using krfb :?
Thanks anyway guys!

Running iptables is what alleviates the risk of running another service. If only one machine is allowed to connect to it then it's only vulnerable from that one machine, and that's only *if* it's vulnerable in the first place. If you aren't worried about running iptables because you are behind a firewall then why would you care about running one more service? I don't understand.

[Ice9]

Of course you're right about the fact that I shouldn't be too worried about running krfb password protected given the fact that I don't even care to run iptables on my workstations.
The only explana§tion I can give you is that the less stuff runs continuously on my machines, the better it makes me feel and the less I worry

So I will be giving realvnc a try I think and meanwhile try to get krfb running again because everything seems to connect fine and then the desktop appears for a few seconds and then disappears without error message!