|
Softpanorama
(slightly skeptical)
Open Source Software Educational Society |
May the
source be with you,
but remember the KISS principle ;-)
|
VNC on Linux
If you are running the Gnome desktop then you already have a VNC server
built in. Click Desktop > Preferences
> Remote Desktop to open the dialog, make sure that all four options
displayed are clicked, select the password and you are in the game. For
gnome users the built-in Vino (VNC server for
Gnome) is more efficient then stand-alone solution. It is OK for older
(non dual-core) PC and laptops too. Please note that in RHEL 4 and
OpenSuse10.2 vino is not installed by default
and you need to install the RPM manually to make it work.
The main problem with vino is that it does not support copy/paste with Windows
client.
In this sense you are better off using X11vnc.
The same Remote Desktop option exists for KDE but krfb,
a VNC compatible server for the KDE desktop,
which implements this option is slow and
very resource hungry. It is not recommended for older PCs (you
might have up to 80% of CPU consumed by krfb).
That means that until version 4.0 KDE did not have a good analog to Vino.
Unless you have dual core CPU and a lot of RAM you should not even try
krfb. Here is a typical post about the problem
on a small desktop (NDS
Engineers Support Forums):
Hi, I'm running Linux Suse 9.0 like a VM with Vmware ESX 2.1
The kernel version is 2.4.21-246smp4G , the KDE version 3.1.4
Everytime that I connect remotely the krfb process use 100% of the CPU all
the time, check my top statistics, any ideas
thanks
Artiman
________________________________
top - 08:30:45 up 19:48, 3 users, load
average: 1.69, 1.52, 0.77
Tasks: 83 total, 4 running, 78 sleeping, 0 stopped, 1 zombie
Cpu(s): 20.7% user, 76.9% system, 0.0% nice, 2.4% idle
Mem: 255072k total, 250764k used, 4308k free, 40168k buffers
Swap: 514040k total, 0k used, 514040k free, 108544k cached
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
2761 root 25 0 15712 15m 10m R 43.6 6.2 3:38.77 krfb
911 root 25 0 14784 10m 2420 R 34.4 4.1 42:31.89 X
2757 root 16 0 15712 15m 10m S 16.9 6.2 1:43.51 krfb
2797 root 15 0 17460 17m 14m R 1.0 6.8 0:01.23 kdeinit
1031 root 15 0 15308 14m 13m S 0.3 6.0 0:02.51 kdeinit
Therefore, a better option is to use X11vnc. I've found X11vnc to be a very
reliable server.
| Default desktop sharing on KDE 3.x is available but practically
unusable because krfb, a VNC compatible
server for the KDE desktop, is very
slow and very resource hungry. |
To configure desktop sharing you need to click the menu
Configure Desktop -> Desktop -> Internet and Network
-> Desktop Sharing. After that you can click all four option of unclick "Allow
uninvited connected". Then you need to select your password. If you unclick "Allow
uninvited connected" you should use long (longer then 8 characters), preferably
AOL-style ("double words") type of password like NNccru-831123 or XlonG-55927 --
"easy" password without a firewall means significant risk of intrusion. See also
[PDF] The Desktop
Sharing Handbook
By default, VNC is not a secure protocol. While passwords are not sent in plain-text
(as in telnet), brute-force cracking could prove successful if both the encryption
key and encoded password are sniffed from a network. For this reason it is recommended
that a password of at least 8 characters is used. However, VNC may be tunneled over
an SSH or VPN connection adding an extra security layer. SSH tunnels can be created
from any clients.
RealVNC offers high-strength encryption as part of its commercial package.
KDE users can use any lightweight lightweight desktop like
Xfce with
classic VNC for remote access
Most GNU/Linux users choose GNOME or KDE for desktops without thinking. However,
many alternatives exist, ranging from minimalist graphic environments in window
managers like IceWM to entire alternative desktops, such as ROX. Of these alternatives
the best-known and most polished is Xfce. Now at version 4.4, Xfce resembles
a stripped-down version of GNOME, with carefully selected customization options
and utilities, as well as a few thoughtful features of its own.
As detailed on the
download page, Xfce is available
in many distributions. In fact, a growing number of distributions, including
Xbuntu, Dream Linux, and Zenwalk use Xfce by default. Alternatively, you can
build Xfce from source code, or use its graphical installers. However, if you
choose the graphical installers, read the documentation first to make sure you
understand what you are doing, and the extra steps that you might have to take
if you missed a cue from the installation wizard.
X11vnc provides the view of the view of real X display similar to WinVNC. Starting
from version 0.9 it also contains several useful extensions pioneered by UltraVNC.
x11vnc is a program that allows one to remotely view and interact with real
X displays (i.e. a display corresponding to a physical monitor, keyboard, and
mouse) with any VNC viewer. It is similar to WinVNC and is designed to be compatible
with all Unix variants and depend on a very small set of standard libraries.
It supports a growing number of command line options, such as -nofb for dual-
headed mode with Win2VNC. It is part of the LibVNCServer project.
Release focus: Minor feature enhancements
Changes:
VNC Service advertising via mDNS (also known as ZeroConf or BonJour) is supported
by the Avahi library. UltraVNC's TextChat, SingleWindow, and ServerInput extensions
are supported (requires the UltraVNC or SSVNC viewer). Short aliases -find,
-create, -svc, and -xdmsvc for common usage modes are added (e.g. to find a
user's X display or create a new one with Xvfb). Reverse VNC connections (viewer
listening) now work in -ssl mode. XDAMAGE use is automatically disabled if it
appears to not be working properly (it often does not work with OpenGL applications
like Beryl and MythTV).
Author:
Karl Runge
[contact developer]
We strongly recommend
TightVNC viewer
as it includes a number of nice features over the
official VNC client.
It can work iether with TightVNC server or with the standard server. An x11vnc
project provides an Enhanced
TightVNC Viewer package (SSVNC) for Unix, Windows, and Mac OS X
with automatic SSL and/or SSH tunnelling support,
SSL Certificate creation; and on Unix: NewFBSize, ZRLE, cursor alphablending, and
low color modes support. Also on Unix the UltraVNC Text Chat, Single Window, Server
Input, and 1/n Scaling extensions are supported. This bundle could be placed on,
say, a USB memory stick for SSL/SSH VNC viewing from nearly any networked computer.
The Tight VNC modifications take effect in the client and server, but it’s the
client changes that people appreciate most. The user has three options to
connect: best compression, fast compression and listen mode. Best compression uses
JPEG compression to give you the fastest connection speed, along with the integrated
data compression schemes. Fast compression uses data compression but doesn’t do
the JPEG compression. All-in-all fast compression looks good and operates with reasonable
speed. Actually if you are on 100Mb network on local LAN it does not matter :-).
All in all VNC is an amazing piece of free software that gets the job done.
Tight VNC makes a great program even better.
The TightVNC viewer is
available as a pre-compiled binary or as source code. Only download the source if
you are familiar with building packages or have an OS which doesn't have pre-built
binaries.
VNC Client Display Resolution
Depending on your VNC use, you may want to have a larger or smaller display than
the default or a different number of colors. This often happens if you want to run
the display full-screen or want to save your reduce the information over your network
connection by choosing a smaller color set or resolution. The VNC server allows
you to choose a resolution and color depth by connecting to different ports. Usually
port 5995 is used, which corresponds to a 1024x768 resolution with 16 bit color,
however you can choose any port 5991 to 5999.
Choose a resolution (800x600, 1024x768, or 1280x1024) and a color depth (8 bit,
16 bit, or 24 bit) and find the corresponding port in the following table.
| Port |
Resolution |
Color Depth |
| 5991 |
800x600 |
8 bit |
| 5992 |
800x600 |
16 bit |
| 5993 |
800x600 |
24 bit |
| 5994 |
1024x768 |
8 bit |
| 599 |
1024x768 |
16 bit |
| 5996 |
1024x768 |
24 bit |
| 5997 |
1280x1024 |
8 bit |
| 5998 |
1280x1024 |
16 bit |
| 5999 |
1280x1024 |
24 bit |
Checking local display setting
It is useful to know your local display's settings for choosing a VNC display.
For instance, to make a full screen display you
would match the local display resolution with the VNC display resolution.
The resolution for the iMacs defaults to 1024x768 and the Suns in the Asprey
lab default to 1280x1024. Here are instructions for finding the local display
settings on several popular operating systems.
- Windows. You can find resolution and color settings by looking
at the "Control Panel", in the "Display" section, under the "Settings" tab.
- Linux. You can find display information in the
XF86Config file (assuming you use XFree86,
which is the norm currently for all major distributions). This file is typically
located in /etc/X11/ or
/usr/X11R6/lib/X11/.
|
|
Notes:
- This is a Spartan WHYFF (We Help
You For Free) site written by people for whom English
is not a native language.
Some amount of grammar and spelling errors should be
expected.
- The site contain some broken links
as it develops like a living tree...
Please try to use Google, Open directory,
etc. to find a replacement link (see
HOWTO search the WEB for details). We would appreciate
if you can
mail us a correct link.
|
|
|
SOLVED] Re: using vino/vncviewer
> you can still run a stand-alone vnc
server (does not use the current
> desktop). several, in fact. OR you can
simply ssh into the box and
> run an X11 application and it will
show up on the screen that you are
> currently using if you have an Xserver
running there (linux in
> graphical mode, or windows with 3rd
party software - ie
> hummingbird($$), cygwin(free) ).
>
> the vnc server route gives you the
option of disconnecting and
> reconnecting from the session without
the programs terminating
> (somewhat like remote desktop in
windows).
>
SuSE has a very nice setup, but as my
SuSE box is currently running
Mepis I don't have the recipe.
It runs the server out of xinetd, and
you get a standard dm login screen.
Red Hat does it differently, and I have
the recipe for something similar
because I've adapted it.
I run a script at boot time along with
all the others in /etc/init.d
Here's the script:
summer@Kookaburra:~$ cat /etc/init.d/vnc
#!/bin/bash
# If no config, do nothing
[ -f /etc/vncserver.conf ] || exit 0
function cfg()
{
sed </etc/vncserver.conf \
-e 's=#.*$==g' \
| grep -v '^$'
}
case "$1" in
start)
cfg | while read user port options
do :
echo Starting session for ${user} on
${port}
eval passwdfile=~${user}/.vnc/passwd
if [ ! -f ${passwdfile} ] ; then
echo Cannot start session for ${user},
no passwd file
continue
fi
P=/usr/local/bin:/usr/bin:/bin:/usr/bin/X11:/usr/g
ames
[ "${user}" = "root" ] &&
P=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bi
n:/sbin:/bin:/usr/bin/X11
su - ${user} -c "PATH=${P} vncserver
${options} ${port}"
done
;;
stop)
cfg | while read user port options
do :
echo Stopping session for ${user} on
${port}
eval passwdfile=~${user}/.vnc/passwd
if [ ! -f ${passwdfile} ] ; then
echo Cannot stop session for ${user}, no
passwd file
continue
fi
su - ${user} -c "vncserver -kill
${port}"
done
;;
*)
echo ${0} '[start|stop]'
;;
esac
summer@Kookaburra:~$
Here's the config file:
summer@Kookaburra:~$ cat /etc/vncserver.conf
# vncserver configuration: sessions to
start automatically
# User display <options>
root :55 -geometry 1600x1200
suzanne :1 -geometry 1024x850
summer@Kookaburra:~$
1600x1200 us the resolution of the
screen I connect from. I run the
client full-screen. Colours can be a bit
strange, but otherwise it works
very well.
You can also configure your dm to accept
remote clients, then run X thus:
X -query garage.home.lan
I generally do that from inittab.
You switch with the usual ctrl-alt-F7
etc.
Finally, here is a great article that
touches on this:
http://www.linuxworld.com/story/32827.htm
Just slip Ubuntu in in place of those
other distroes whereever you like.
Calvin Webster cwebster "at" ec.rr.com
Fri Apr 28 22:47:01 2006
I've been meaning to do this for quite some time. I figured this was a
good opportunity to pass on my experience in setting up VNC on our
network. VNC has become one of the most useful tools I've ever used. It
allows me to do the work of several administrators by eliminating most
of the time required to physically touch a remote computer.
I manage several interconnected LANs and network services spread across
4 buildings. Each building houses one or more offices and training
facilities consisting of various blends of hardware/software platforms,
applications, and users. If your network is anywhere near as diversified
as ours, you'll need to do some research to get VNC running on all your
platforms, but this should get you started using it in the way I think
most people expect.
This collection of notes is very simplified, assuming the reader has
reasonable Linux sysadmin skills and experience. Although the VNC
documentation is comprehensive, some key configuration details seemed to
be missing or hard to find for the setup we needed here. I've tried to
cover them below.
MS Windows installations are pretty straightforward since it's a
single-user OS. Just login as Administrator and run the InstallShield
installer, then configure. I setup all our Windows machines with the
Administrator password. Unfortunately (or fortunately, depending on your
perspective) this means that only the sysadmin can connect to these
machines. However, it also installs the VNC client with which users can
connect to network servers. On our network we have Unix/Linux
development machines to which they connect this way.
Any Unix/Linux machine that you can get GCC on will support VNC. Most
Unix users I talk to expect to get a graphical login when they connect
so I set it up to use the XDM login, just like it would if you were
standing in front of the console.
I'll keep an eye on this thread for a while. If I've left anything out
I'll try to fill in the blanks. One last warning: watch out for wrapped
lines below.
--Cal Webster
## References:
Documentation for VNC Free Edition 4.1:
http://www.realvnc.com/products/free/4.1/
Other Multi-resolution Examples:
http://www.realvnc.com/pipermail/vnc-list/2005-March/049889.html
Documentation for RHEL 4:
https://www.redhat.com/docs/manuals/enterprise/
## Notes:
32-bit color depths didn't work for me I'm offering only 8, 16, and 24
bit
"True colour" for 32-bit setting is uneven for rgb and shift settings
24-bit setting evaluates to "32 bits per pixel" in the "VNC server
default format"
Native X display (root console :0) uses default resolution of 8-bit
1024x768
## Goals:
To provide users with a method of connecting to servers with a
graphical user interface from any workstation platform without
saturating network bandwidth or requiring expensive, bandwidth-hungry
3rd party connectivity solutions (like Hummingbird Exceed).
To provide system/network administrators with a method of remotely
supporting and maintaining server and client computers regardless of
their host platform.
To provide the means to support on-the-spot training and
troubleshooting during a helpdesk call.
## Security:
Examples shown below use somewhat relaxed security settings. You may
want to use more paranoid settings if your network is at high risk. For
example, you may choose to restrict VNC server to "localhost"
connections and require clients to tunnel their VNC connections using
SSH. You DEFINITELY want use this method if going over the public
Internet. Bear in mind that this will limit available network bandwidth
due to the encryption overhead inherent in the tunnel. If there is not
enough available bandwidth for a given color depth, VNC will
automatically throttle back to the most appropriate color depth.
If your network manager allows, and your perimeter and host security
defenses are sufficient, you can take simple precautions without using
SSH tunneling while maintaining a high degree of VNC functionality.
I highly recommend setting a password for the VNC "Native X Display"
(root console :0) even if you have a secure network. See last item in
examples. All other displays can use the XDM login authentication. The
reason for this is that anyone could take control of a root user session
if, for example, the sysadmin walked away from the terminal. The virtual
displays are only ever visible to the person who made the connection so
there's no danger of this.
## Examples:
The examples shown below come from a working configuration used in a
homogeneous network environment consisting of various MS Windows
platforms, Unix flavors, and Linux distributions. All except the oldest
have VNC server and viewers installed. The example represents only RHEL
4, but configuration would be very similar for other Unixes.
## Our Platform (you don't need that much hardware):
CPU: Dual Dual-core Xeon 3.6 GHz
MEM: 8 GB
DISK: 1.5 TB RAID 0/1
OS: RHEL 4 AS
VNC: 4.1.1-1
Xorg: 6.8.2-1.EL.13.25
################################
## Begin VNC Server on RHEL 4 ##
################################
## Legend:
... The appearance of an ellipsis indicates that the entries
to/from this point are insignificant or repeat.
=== Encloses part or all of the contents of a sample file.
--- Separates sections of a file or separates title or
heading from content
## First, download and install the latest VNC RPM at:
http://www.realvnc.com/products/free/4.1/download.html
## Ensure system security is set to allow VNC connections to ports
you've configured
5900 is default TCP port
I'm also using ports 5952 5953 5962 5963 5972 5973 5980
One simple way is:
===============
/etc/hosts.deny
---------------
ALL: ALL
===============
================
/etc/hosts.allow
----------------
ALL: 192.168.1. 192.168.2. 192.168.3. 192.168.32. 10.1.150.
================
## Ensure that your system is set to startup in run level 5 with XDM
(GDM)
============
/etc/inittab
------------
...
id:5:initdefault:
...
# Run xdm in runlevel 5
x:5:respawn:/etc/X11/prefdm -nodaemon
============
======================
/etc/sysconfig/desktop
----------------------
DESKTOP="GNOME"
======================
=====================================================
diff /etc/X11/gdm/gdm.conf.orig /etc/X11/gdm/gdm.conf
-----------------------------------------------------
52c52
< #RemoteGreeter=/usr/bin/gdmlogin
---
> RemoteGreeter=/usr/bin/gdmlogin
211c211
< Enable=false
---
> Enable=true
214c214
< #HonorIndirect=true
---
> HonorIndirect=true
227a228
> DisplaysPerHost=4
230a232
> PingIntervalSeconds=300
298c300
< #ChooserButton=true
---
> ChooserButton=true
=====================================================
=====================
/etc/X11/gdm/gdm.conf
---------------------
[daemon]
AutomaticLoginEnable=false
AutomaticLogin=
TimedLoginEnable=false
TimedLogin=
TimedLoginDelay=30
Greeter=/usr/bin/gdmgreeter
RemoteGreeter=/usr/bin/gdmlogin
DefaultPath=/usr/local/bin:/usr/bin:/bin:/usr/X11R6/bin
RootPath=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/usr/X11R6/bin
User=gdm
Group=gdm
LogDir=/var/log/gdm
PidFile=/var/run/gdm.pid
PostLoginScriptDir=/etc/X11/gdm/PostLogin/
PreSessionScriptDir=/etc/X11/gdm/PreSession/
PostSessionScriptDir=/etc/X11/gdm/PostSession/
DisplayInitDir=/etc/X11/gdm/Init
XKeepsCrashing=/etc/X11/gdm/XKeepsCrashing
ServAuthDir=/var/gdm
BaseXsession=/etc/X11/xdm/Xsession
DefaultSession=default.desktop
UserAuthDir=
UserAuthFBDir=/tmp
UserAuthFile=.Xauthority
StandardXServer=/usr/X11R6/bin/X
Xnest=/usr/X11R6/bin/Xnest -audit 0 -name Xnest
[security]
AllowRoot=true
AllowRemoteRoot=true
AllowRemoteAutoLogin=false
RelaxPermissions=0
CheckDirOwner=true
[xdmcp]
Enable=true
HonorIndirect=true
DisplaysPerHost=4
PingIntervalSeconds=300
[gui]
GtkTheme=Bluecurve
[greeter]
TitleBar=false
ConfigAvailable=false
Browser=false
MinimalUID=500
Logo=
ChooserButton=true
BackgroundColor=#20305a
ShowGnomeFailsafeSession=false
ShowLastSession=false
GraphicalTheme=Default
GraphicalThemeDir=/usr/share/gdm/themes/
[chooser]
HostImageDir=/usr/share/hosts/
Hosts=
Broadcast=true
Multicast=false
[debug]
Enable=false
[servers]
0=Standard
[server-Standard]
name=Standard server
command=/usr/X11R6/bin/X -audit 0
flexible=true
[server-Terminal]
name=Terminal server
command=/usr/X11R6/bin/X -audit 0 -terminate
flexible=false
handled=false
[server-Chooser]
name=Chooser server
command=/usr/X11R6/bin/X -audit 0
flexible=false
chooser=true
=====================
## Add entries to /etc/services for display variations you will use
=============
/etc/services
-------------
...
# VNC Servers
vnc 5950/tcp # VNC Service (using defaults)
vnc1024x768x8 5952/tcp # VNC Service 1024x768, 8-bit color
depth
vnc1280x1024x8 5953/tcp # VNC Service 1280x1024, 8-bit color
depth
vnc1024x768x16 5962/tcp # VNC Service 1024x768, 16-bit color
depth
vnc1280x1024x16 5963/tcp # VNC Service 1280x1024, 16-bit color
depth
vnc1024x768x24 5972/tcp # VNC Service 1024x768, 24-bit color
depth
vnc1280x1024x24 5973/tcp # VNC Service 1280x1024, 24-bit color
depth
vnc1280x960x24 5980/tcp # VNC Service 1280x960, 24-bit color
depth
...
=============
## Create a VNC startup script for xinetd to start all necessary
services for your virtual VNC displays.
=================
/etc/xinetd.d/vnc
-----------------
# default: off
# description: VNC accepts connections from VNC viewers using XDMCP to \
# manage the connections.
## [50] Default options: Color Depth: 16 Geometry 1024x768
service vnc
{
flags = REUSE
protocol = tcp
socket_type = stream
wait = no
user = nobody
server = /usr/bin/Xvnc
server_args = -inetd -query localhost -once
-securitytypes=none
disable = no
}
## [52] Color Depth: 8-bit Geometry: 1024x768
service vnc1024x768x8
{
flags = REUSE
protocol = tcp
socket_type = stream
wait = no
user = nobody
server = /usr/bin/Xvnc
server_args = -inetd -query localhost -once -geometry
1024x768 -depth 8 -securitytypes=none
disable = no
}
## [53] Color Depth: 8-bit Geometry: 1280x1024
service vnc1280x1024x8
{
flags = REUSE
protocol = tcp
socket_type = stream
wait = no
user = nobody
server = /usr/bin/Xvnc
server_args = -inetd -query localhost -once -geometry
1280x1024 -depth 8 -securitytypes=none
disable = no
}
## [62] Color Depth: 16-bit Geometry: 1024x768
service vnc1024x768x16
{
flags = REUSE
protocol = tcp
socket_type = stream
wait = no
user = nobody
server = /usr/bin/Xvnc
server_args = -inetd -query localhost -once -geometry
1024x768 -depth 16 -securitytypes=none
disable = no
}
## [63] Color Depth: 16-bit Geometry: 1280x1024
service vnc1280x1024x16
{
flags = REUSE
protocol = tcp
socket_type = stream
wait = no
user = nobody
server = /usr/bin/Xvnc
server_args = -inetd -query localhost -once -geometry
1280x1024 -depth 16 -securitytypes=none
disable = no
}
## [72] Color Depth: 24-bit Geometry: 1024x768
service vnc1024x768x24
{
flags = REUSE
protocol = tcp
socket_type = stream
wait = no
user = nobody
server = /usr/bin/Xvnc
server_args = -inetd -query localhost -once -geometry
1024x768 -depth 24 -securitytypes=none
disable = no
}
## [73] Color Depth: 24-bit Geometry: 1280x1024
service vnc1280x1024x24
{
flags = REUSE
protocol = tcp
socket_type = stream
wait = no
user = nobody
server = /usr/bin/Xvnc
server_args = -inetd -query localhost -once -geometry
1280x1024 -depth 24 -securitytypes=none
disable = no
}
## [80] Color Depth: 24-bit Geometry: 1280x960
## (special for Dennis)
service vnc1280x960x24
{
flags = REUSE
protocol = tcp
socket_type = stream
wait = no
user = nobody
server = /usr/bin/Xvnc
server_args = -inetd -query localhost -once -geometry
1280x960 -depth 24 -securitytypes=none
disable = no
}
=================
## Setup X to use the VNC Native display server for the root console :0
==================
/etc/X11/xorg.conf
------------------
...
Section "Module"
...
Load "vnc"
EndSection
...
Section "Screen"
Identifier "Screen0"
...
Option "SecurityTypes" "VncAuth"
Option "UserPasswdVerifier" "VncAuth"
Option "PasswordFile" "/root/.vnc/passwd"
EndSection
...
==================
## As "root" user set a vnc password for the VNC "Native Display" server
vncpasswd
(creates /root/.vnc/passwd)
## You'll have to restart the X server and xinetd to get things rolling.
## You may be able to do this using <Ctrl><Alt><Backspace> at a login
prompt.
If you're not already setup to boot into run level 5 with a respawning
xdm you may need to do a system restart.
## You'll need to restart xinetd to get it to re-read the config files.
service xinetd restart
## Lastly, you need to test connections from another machine upon which
you've already installed a VNC Viewer (client).
################################
## Begin VNC Server on RHEL 4 ##
################################
##################################
## Begin Java VNC Viewer Client ##
##################################
## To get the web server to offer a Java VNC client:
mkdir /var/www/html/vnc
cp /usr/share/vnc/classes/* /var/www/html/vnc/
## Add something like this to one of your html pages:
(I have a support page where we maintain tool links)
/var/www/html/support.html
=========================================================
...
<P><B><A HREF="documentation.html"> Documentation</A></B>
<P><B><A HREF="http://pegasus/vnc/index.vnc">VNC Viewer (Java)</A></B>
<P><B><A HREF=JavaScript: onclick="mindTerm();"
...
=========================================================
## You may have authentication problems when trying to connect to
machines other than the one on which the VNC jar file is installed. If
you want to use it this way you may need to "sign" the jar file. That's
beyond the scope of this post. A simpler way to use the Java client is
to copy it to your client machine and run it directly.
## Run the Java VNC client directly:
Note: It's just as simple, if not more so, to install the Windows VNC
version so that's what I do.
## Install the latest JRE from the Sun Java site:
http://www.java.com/en/download/index.jsp
## Copy the "vncviewer.jar" file to the (windoze) client machine
C:\Program Files\RealVNC\VNC4\vncviewer.jar
## Create a menu item or shortcut executing the jar file:
Target: "C:\Program Files\RealVNC\VNC4\vncviewer.jar"
Start in: "C:\Program Files\RealVNC\VNC4\"
################################
## End Java VNC Viewer Client ##
################################
Corné Beerse
cbeerse at lycos.nl
Mon Aug 30 09:27:48 CEST 2004
Nepple, Bruce wrote:
> This happens in 5.4 and 5.3
>
> I'm running xfce3 under linux through vnc4
>
> I'm using nc with about 60 open sessions.
>
> Ctrl-c and ctrl-v don't work. They have worked
> in the past, but not now. If I start a new
> nedit session (not nc), it doesn't work either.
>
> Middle mouse select/pasting works fine.
>
> I suspect that it is desktop/vnc related, but
> hopefully someone will have an idea where
> to start looking.
I'm roughly sure it is vnc related... The vnc-session (viewer and/or server) do
only transfer the select-buffer from/to the X11 side. Other buffers are roughly
not touched.
With vnc (well with version 3 or related at least) the copy-paste actions
between a m$windows desktop and a unix-vnc-server do work in `xterm` and related
"older" applications but not in current applications that do have cut-copy-paste
menu options. With xclipboard you can roughly see whats happening and you can
use that to get things going, at least as current workaround.
I do know stuff has changed in this area with the newer vnc version 4 but I
still have not tested details. I already do know it is related to the version at
the server (remote) side.
CBee
VNC server startup
I am using vnc (Release 3.3.3.r2-362) under SuSE 8.1.
If you don't have it installed get it from SuSE 'YAST2 Control Center': Install
or Remove Software: Package Groups: X11: Utilities. You can then also try for
'Online update' to see if there is a newer version.
You will get files in:
/usr/X11R6/bin/ (Xvnc,vncpasswd, vncserver, vncviewer)
/usr/share/doc/packages/vnc (Documentation)
/usr/share/vnc/classes/ (Java classes for jvncviewer)
The script vncserver is a wrapper for
Xvnc. I have changed the startup environment
because I am using KDE. The change is on line 47; it now reads:
startkde #&\n); The modified 'vncserver'
is shown below.
. . .
. . .
$defaultXStartup
= ("#!/bin/sh\n\n".
"xrdb \$HOME/.Xresources\n".
"xsetroot -solid grey\n".
"xterm -geometry 80x24+10+10 -ls -title \"\$VNCDESKTOP Desktop\" &\n".
"startkde &\n");
chop($host = `uname -n`);
. . .
. . .
In my setup I wanted to have the vncservers to come up at boot time and keep
their context even after disconnecting the vnc-viewer. Some people prefer to
start VNC through inetd, but this always gives you a fresh desktop and is also
slow in starting up. I don't think that in my configuration I have a security
issue; the server is behind a firewall with only http and smtp ports open. The
local network is purely private (home LAN).
In order to achieve this I created a boot script called
xvncserver under /etc/init.d
which is included below as xvncserver.
#! /bin/sh
#
# Author: Willem van der Mark <wvdmark@computer.org>
#
# /etc/init.d/xvncserver this Script
# /usr/sbin/rcvncserver Root-Link to this Script
# /usr/X11R6/bin/vncserver Program
#
# System startup script for vnc server
#
# LSB compatible service control script; see http://www.linuxbase.org/spec/
#
# Note: This template uses functions rc_XXX defined in /etc/rc.status on
# UnitedLinux (UL) based Linux distributions. If you want to base your
# script on this template and ensure that it works on non UL based LSB
# compliant Linux distributions, you either have to provide the rc.status
# functions from UL or change the script to work without them.
#
#
### BEGIN INIT INFO
# Provides: xvncserver
# Required-Start: $remote_fs $syslog $network xdm
# X-UnitedLinux-Should-Start: $network xdm
# Required-Stop: $remote_fs $syslog $network xdm
# X-UnitedLinux-Should-Stop: $network xdm
# Default-Start: 3 5
# Default-Stop: 0 1 2 6
# Description: Start vncserver for remote control
#
### END INIT INFO
# Check for missing binaries
VNC_WRAPPER=/usr/X11R6/bin/vncserver
test -x $VNC_WRAPPER || exit 5
VNC_MASTER=/usr/X11R6/bin/Xvnc
test -x $VNC_MASTER || exit 5
VNC_CONFIG=/etc/sysconfig/vncservers
test -r $VNC_CONFIG || exit 5
# Shell functions sourced from /etc/rc.status:
# rc_check check and set local and overall rc status
# rc_status check and set local and overall rc status
# rc_status -v ditto but be verbose in local rc status
# rc_status -v -r ditto and clear the local rc status
# rc_failed set local and overall rc status to failed
# rc_failed <num> set local and overall rc status to <num><num>
# rc_reset clear local rc status (overall remains)
# rc_exit exit appropriate to overall rc status
# rc_active checks whether a service is activated by symlinks
. /etc/rc.status
# First reset status of this service
rc_reset
# Return values acc. to LSB for all commands but status:
# 0 - success
# 1 - generic or unspecified error
# 2 - invalid or excess argument(s)
# 3 - unimplemented feature (e.g. "reload")
# 4 - insufficient privilege
# 5 - program is not installed
# 6 - program is not configured
# 7 - program is not running
#
VNCSERVERS=""
VNCARGS=""
[ -f $VNC_CONFIG ] && . $VNC_CONFIG
prog=$"VNC server"
case "$1" in
start)
for display in ${VNCSERVERS}
do
if test -a /home/${display##*:}/.vnc/passwd ; then
rm -fv /tmp/.X${display%%:*}-lock
rm -fv /tmp/.X11-unix/X${display%%:*}
echo -n "Starting $prog on: ${display} -- "
su ${display##*:} -l -c "cd && vncserver :${display%%:*} ${VNCARGS}"
[ $? -eq 0 ] && echo $rc_done_up || echo $rc_failed_up
else
echo -n "Vnc not initialised for user: ${display##*:}"
echo $rc_failed ;
fi
done
;;
stop)
for display in ${VNCSERVERS}
do
echo -n "Shutting down $prog: ${display} "
su ${display##*:} -c "vncserver -kill :${display%%:*}" >/dev/null 2>&1
[ $? -eq 0 ] && echo $rc_done || echo $rc_failed
done
;;
restart)
$0 stop
$0 start
rc_status
;;
status)
echo -n "Checking for service Vnc-Server "
## Check status with checkproc(8), if process is running
## checkproc will return with exit status 0.
# Return value is slightly different for the status command:
# 0 - service running
# 1 - service dead, but /var/run/ pid file exists
# 2 - service dead, but /var/lock/ lock file exists
# 3 - service not running
# NOTE: checkproc returns LSB compliant status values.
checkproc $VNC_MASTER
rc_status -v
;;
*)
echo "Usage: $0 {start|stop|status|restart}"
exit 1
;;
esac
rc_exit
It is based on the skeleton provided in init.d and get its parameters from
a file called 'vncservers' in /etc/sysconfig/. It contains 2 variables 'VNCSERVERS'
and 'VNCARGS'. VNCSERVERS gives a series of 'screen number:user account' for
each vnc-server you want to start. (not the root account; does not work, has
not been tested, and it not recommendable). VNCARGS provides some extra parameters
that will be passed to 'vncserver' or 'Xvnc'. This file is called
vncservers. In this example the geometry of 940x705
prevents the vnc-viewer from clipping the Start bar in both Windows and Mac.
# The VNCSERVERS variable is a list of display:user pairs.
#
# Uncomment the lines below to start a VNC server on display :1
# as my 'myusername' (a legal user). This user will also
# need to set a VNC password; run 'man vncpasswd' to see how
# to do that.
#
# DO NOT RUN THIS SERVICE if your local area network is
# untrusted! For a secure way of using VNC, see
# URL:http://www.uk.research.att.com/vnc/sshvnc.html.
#
# VNCSERVERS="1:myusername ... ..."
#
VNCSERVERS="3:user1 4:user2"
# The VNCARGS variable contains arguments to vncserver (and Xvnc)
# which will be passed to all sessions; run 'man vncserver' or
# 'man Xvnc' to see which arguments are to be used.
#
# VNCARGS="-vncserversargs -Xvncargs"
#
VNCARGS="-geometry 940x705 -depth 16 -alwaysshared"
These options are then configurable in YAST2 'Editor for Sysconfig' under
+etc: the following images
What is VNC?
VNC stands for Virtual Network Computing. It is remote control software which
allows you to view and interact with one computer (the "server") using a simple
program (the "viewer") on another computer anywhere on the Internet. The two
computers don't even have to be the same type, so for example you can use VNC
to view an office Linux machine on your Windows PC at home. VNC is freely and
publicly available and is in widespread active use by millions throughout industry,
academia and privately.
For more information, please visit
http://www.realvnc.com/
Do I have it in my system?
Type following command to check if you have the client and server installed
in your system.
[tchung@tchung101 tchung]$ rpm -q vnc vnc-server
vnc-4.0-0.beta4.3.2
vnc-server-4.0-0.beta4.3.2
[tchung@tchung101 tchung]$
###
To configure vncserver as a service on your system, add yourself in following
config file.
[tchung@tchung101 tchung]$ sudo vi /etc/sysconfig/vncservers
# The VNCSERVERS variable is a list of display:user pairs.
#
# Uncomment the line below to start a VNC server on display :1
# as my 'myusername' (adjust this to your own). You will also
# need to set a VNC password; run 'man vncpasswd' to see how
# to do that.
#
# DO NOT RUN THIS SERVICE if your local area network is
# untrusted! For a secure way of using VNC, see
# URL:http://www.uk.research.att.com/vnc/sshvnc.html
# VNCSERVERS="1:myusername"
VNCSERVERS="1:tchung"
###
Before starting vncserver as a service, let's create a vnc password with
vncpasswd command.
Notice it creates a hidden directory .vnc under your home account with
file passwd which contains your vnc password.
[tchung@tchung101 tchung]$ vncpasswd
Password:
Verify:
[tchung@tchung101 tchung]$ ls -d .vnc
.vnc
[tchung@tchung101 tchung]$ ls .vnc
passwd
[tchung@tchung101 tchung]$
###
Now let's start vncserver as a service.
[tchung@tchung101 tchung]$ sudo /sbin/service vncserver start
Starting VNC server: 1:tchung [ OK ]
[tchung@tchung101 tchung]$
Take a look at the contents of .vnc directory now. You should have something
similiar to following.
[tchung@tchung101 tchung]$ cd .vnc
[tchung@tchung101 .vnc]$ ls
passwd tchung101:1.log tchung101:1.pid xstartup
[tchung@tchung101 .vnc]$
If you edit the script called xstartup, you will notice following
comment in red.
Uncomment those two lines in red as shown below!!!
Otherwise, you will get nothing but grey screen.
#!/bin/sh
# Uncomment the following two lines for normal desktop:
unset SESSION_MANAGER
exec /etc/X11/xinit/xinitrc
[ -x /etc/vnc/xstartup ] && exec /etc/vnc/xstartup
[ -r $HOME/.Xresources ] && xrdb $HOME/.Xresources
xsetroot -solid grey
vncconfig -iconic &
xterm -geometry 80x24+10+10 -ls -title "$VNCDESKTOP Desktop" &
twm &
###
Since we've just edited vnc startup script, let's restart the vncserver.
[tchung@tchung101 tchung]$ sudo /sbin/service vncserver restart
Shutting down VNC server: 1:tchung [ OK ]
Starting VNC server: 1:tchung [ OK ]
[tchung@tchung101 tchung]$
So how do I connect to vncserver? Use vncviewer command in vnc client
as following.
[tchung@tchung101 tchung]$ vncviewer localhost:1
Enter your vnc password and here is the result:
Screenshot
UPDATE:
To connect to a remote system with firewall, port 5901 needs to be open.
Add following line in red to open port 5091 and restart iptables service.
[tchung@tchung101 tchung]$ sudo vi /etc/sysconfig/iptables
# Firewall configuration written by redhat-config-securitylevel
# Manual customization of this file is not recommended.
*filter
:INPUT ACCEPT [0:0]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
:RH-Firewall-1-INPUT - [0:0]
-A INPUT -j RH-Firewall-1-INPUT
-A FORWARD -j RH-Firewall-1-INPUT
-A RH-Firewall-1-INPUT -i lo -j ACCEPT
-A RH-Firewall-1-INPUT -p icmp --icmp-type any -j ACCEPT
-A RH-Firewall-1-INPUT -p 50 -j ACCEPT
-A RH-Firewall-1-INPUT -p 51 -j ACCEPT
-A RH-Firewall-1-INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
-A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp --dport 22 -j ACCEPT
-A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp --dport 5901 -j ACCEPT
-A RH-Firewall-1-INPUT -j REJECT --reject-with icmp-host-prohibited
COMMIT
[tchung@tchung101 tchung]$ sudo /sbin/service iptables restart
Flushing firewall rules: [ OK ]
Setting chains to policy ACCEPT: filter [ OK ]
Unloading iptables modules: [ OK ]
Applying iptables firewall rules: [ OK ]
[tchung@tchung101 tchung]$
In case of broken links
please try to use Google search. If you find the page please notify
us about new location
Recommended papers
VNCOverSSH - Community
Ubuntu Documentation
Set
up the VNC Server in Fedora
Vino (VNC server for Gnome)
Vino. The
Remote Desktop Project
Configuring a VNC server
in Linux bobpeers.com
VNC - Gentoo Linux Wiki
Vino is designed to be used with the Gnome desktop.
It is very easy to setup. The connection is viewable
in windowed mode.
The instructions are simple enough to be given here.
- configure:
- via the GUI:
- vino-preferences &
- OR hack with gconftool:
- gconftool-2 -s -t bool /desktop/gnome/remote_access/enabled
true
- OR hack the gconf xml:
- vi ~/.gconf/desktop/gnome/remote_access/%gconf.xml
- then restart the vino-session
- start:
- vino-session &
Jonh Wendell » Blog Archive » Improvements on Vino (GNOME Remote Access
Desktop)
Vino. The
Remote Desktop Project. Take 2.
RPM
resource vino
NX is an open standard server built on top of X that simplifies thin-client
networking. It includes built-in support for encryption (using SSH), access
to the local filesystem and local audio. The server also is able to translate
foreign protocols to allow connections from RDP and other clients. NX is
a product of NoMachine, which develops an open-source core, on which proprietary
versions of both the server and client are built. FreeNX is a completely
open-source project.
http://fedoranews.org/contributors/rick_stout/freenx/
Cool
Solutions Installing the Latest (As of Oct 2005) FreeNX Server on Novell
Linux products
Warning: Once you used NX you'll NEVER GO BACK to VNC...
It is fast (compression and cache technology applied to the X protocol),
allowing you to work remotely using a higher resolution,... and secure
(it runs over SSH).
Reader Comments
- FreeNX on SLE10 Just tried the following packages
1. nxclient-2.1.0-11.i386.rpm 2. nxnode-2.1.0-15.i386.rpm
3. nxserver-2.1.0-17.i386.rpm from NoMachine on
SLE10. they work fine
- Very nice! I -think- FreeNX comes with SUSE
10 (or it may have been in one of the APT repositories
I've use) , so if you just want to access your home
computer then you can use YAST (or apt / synaptic).
Also, there is a free NXclient for KDE called kNX.
My experience is that it isn't mature enough yet
- it does not work - but your milage may vary.
- Great hints! Thanks for the nice work. Made
my whole nx system work... Just had a problem with
the install of /usr/NX/lib that didn't get covered
in your instructions (but is well described in the
Free-0.4.4/INSTALL file. NX rocks!!!!
- Great article. Just a couple of things to add
1) Need to add nx and other users that will connect
to the sshlogin group in /etc/group 2) Need to import
the client.id_dsa.key in the Configuration->General
area other wise authentication will not work.
- It's not quite as widely supported as VNC though,
eh? A half-dozen linux distros and Solaris, while
VNC is available for anything with a display and
a network connection. Reply: NX Clients run
on Windows, Linux, Mac OSX (BSDs), Solaris and apparently
on some PDA's. Server runs on AFAIK ALL linx distro's,
not half a dozen. NX is more secure and faster than
vnc. NX can do even more: it can also convert RDP
(Remote Desktop Protocol, used by Windows Terminal
Servers) and RFB (used by VNC servers) to NX and
thereby increase efficiency of these two protocols
by a factor of up to 10 across slow links (even
if you compare it to TightVNC!). A possible setup
: Windows Terminal Server --lan--> NXServer --wan-->
NX Client Start reading here http://www.linuxjournal.com/article/8477
Both systems are "free" and open source so as per
usual YOU "HAVE TO" CHOOSE...
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Last modified:
August 08, 2009
,
You just need to use an alternate vnc
server.
November 14th, 2005 at 11:21 am
I utilize vnc for years now and want to point out that there are some other implementations, such as tightvnc[1] or ultravnc[2], works better regarding bandwidth usage,visualisation or feature richness.
[1] http://www.tightvnc.com/
[2] http://ultravnc.sourceforge.net/
polarizers 2cent
http://www.codixx.de/polarizer.html
November 14th, 2005 at 1:51 pm
If you want a ‘Terminal Services’ like login interface. I suggest you try out VNC Session Manager. It supports creating new sessions, and disconnecting from them (and later reconnecting), etc.
November 14th, 2005 at 2:44 pm
Or maybe it would be better to drop an eye on NX technology?
http://nomachine.com
November 14th, 2005 at 2:54 pm
Or on its free implementation at freeNX[1]
[1] http://freenx.berlios.de/
polarizers 2cent
http://www.codixx.de/polarizer.html
November 14th, 2005 at 3:46 pm
polarizer:
Probably, I should have included those links in my post, but I’m glad you posted them. I have tried these VNC implementations myself, they work very well and they certainly have advantages over the original VNC. I wrote this small article because VNC is what comes with the Fedora installation media, so this is the new user’s first acquaintance with remote computing.
Norman Rasmussen:
Your VNC Session Manager sounds very nice! I’ll give it a try in the next days.
Bogdan Mustiata:
Right! I too believe that the NX technology is the future in remote computing. Less consumed bandwidth, native encryption support etc.