remote logon problem

[wilson83]

I really need some help here.

Here is my problem, I have spent hours and hours trying to find some information to get my laptop running windows to be able to connect and display a login to my other computer running fedora 14 over the LAN.

I want to be able to remotely login to my computer running fedora 14 and need to know how to set it up to give a remote GUI login screen on the windows computer. I have installed XMing on the windows computer and I have followed various instructions to set up the fedora 14 machine to give a remote login screen, but to no avail.

Is there a simple way to set the fedora 14 up to give a remote GUI login to the windows computer?

[jpollard]

Not simple. The simple way is to use putty to make a network connection.

The more complex is to use VNC to make a connection. This has a good
bit of additional overhead, but I think it can do a GUI type login.

One reason for the complexity is that Windows doesn't natively support
X. It is possible to get an X server for Windows, but that is only part
of the solution. The next problem is that the X protocol is not good at
security. Normally TCP network based X is disabled because of the
problems.

The standard GUI login utilities don't even support it.

I think putty can forward X protocol to a X server on Windows, but I
don't use Windows much.

The VNC method requires the Fedora system to support one of the
VNC servers (I see tigervnc, and libraries in the F13 repositories, so
I think it is also in the F14 repos). Now getting a VNC client on windows
is unknown to me, but I have read posts about using them. Whether they
are a cost addition I don't know. I understand the VNC connection
presents a virtual console display, so it may then provide a GUI based
login.

[wilson83]

so much for Linux being the Multi-user OS.

I could go the VNC route but you have to stay logged on the linux box and the VNC program just connects to your logged on desktop. like a remote help deal. I have tigerVNC on the windows computer.

I want to connect to the linux machine and get a log on screen. I can connect to windows computers like that.

what needs to be done to do it in linux? I want to stop using windows if I can.

[jpollard]

Linux is a multi-user OS, even more than Windows.
What makes you think it isn't?

Your statement is ambiguous. When you use putty/ssh to connect to
Fedora you get a login request.

I think you need to describe what you want a bit more completely.

[wilson83]

I dont get a log in screen.

Sorry If I was not clear about what I want to do.

1. I want to set up the Fedora 14 machine to remotely display a login screen that any user that can locally log onto the machine can remotely log into the machine.

2. I want to be able to have users on the LAN remotely log onto the Fedora computer at the same time as other users, or the local user. With remote users using computers running windows xp.

I need to know how to set up the Fedora computer (somewhat like a terminal server), and which program to use on the windows machines.

Currently I have Xming on the windows test machine. I have followed various instructions to set up XDMCP, but it doesnt work.

[jpollard]

Better.

You want to use the Windows systems as jXterminals (just the graphics,
keyboard, mouse device).

The problem is that XDMCP is outdated and not secure. The only login
manager that still supports it is xdm, and it has to be enabled, you also
have to disable gdm/kdm and use xdm.

This requires the package xorg-x11-xdm (on F13 where I am this is the
name, and it should be available for F14).

part 1 is switching to xdm - put the line "DISPLAYMANAGER=XDM" in
the file /etc/sysconfig/desktop, and restart. The command sequence

telinit 3
telinit 5

should do this. I have seen reports that this doesn't work sometimes.

The other thing is to enable TCP and XDMCP.

After installing xorg-x11-xdm there should be a directory /etc/X11/xdm
that contains the files you will need. The file Xaccess (and Xservers)
will need to be modified. Xaccess has a commented out line "#*...."
that has an additional comment "#any host can get a login window".
Just remove the "#" from the beginning leaving the "*".

To enable xdm to respond to XDMCP requests, you must
comment out a line in the file xdm-config. This line is
well identified at the end of the file. XDMCP is disabled
by setting the DisplayManager.requestPort parameter to 0.
Commenting this line out should enable XDMCP.

The next file that needs modification is the Xservers file.
This file has to have lines with "hostname:0 foreign" added,
one for each X terminal to be supported.

You might need to restart the xdm after these changes to get
xdm to load them, but some versions will pick it up the next
time the login window is started (either login and logout on
the console, or do a telinit 3/telinit 5 sequence from a virtual
console as root).

The configuration of the X servers on NT must make a XDMCP
request before they will get a Login window.

NOTE: All communication with X servers in this manner will
be unencrypted - any passwords/access control keys used will
be visible to any packet sniffer on the network.

This should get you started...

[Sicinthemind]

http://sourceforge.net/apps/mediawik...Ltsp_DownLoads

LTSP is also known as the Linux Terminal Server Project.
Installation Guide
https://fedorahosted.org/k12linux/wiki/InstallGuide
K12Linux Information
https://fedorahosted.org/k12linux

[beaker_]

Anything wrong with xrdp?

yum install xrdp

Then set it up with xinet or service xrdp rstart. There's also the vnc-ltsp route which will give you gdm (F13) but I've yet to use it in F14.

[wilson83]

Alright, I got it working now. I can get my Fedora 14 GNU log in screen remotely from the windows test computer using either TigerVNC or XMing. Here is what I did if anyone is interested.

First install vnc-server and xinetd

su -
yum install vnc-server
yum install xinetd

Here is the setup.

1. Configure XDMCP

su -
gedit /etc/gdm/custom.conf

make the file look like this

# GDM configuration storage

[daemon]

[security]
DisallowTCP=false

[xdmcp]
Enable=true
DisplaysPerHost=2


[greeter]

[chooser]

[debug]

2. Modify etc/services

su -
gedit /etc/services

make the 5900 section look like this. one vncxxxx line for each resolution you want to display. # out the vnc-server lines. each resolution will be a different port as you can see in the example.

ppsuitemsg      5863/tcp                # PlanetPress Suite Messeng
ppsuitemsg      5863/udp                # PlanetPress Suite Messeng
#vnc-server      5900/tcp                # VNC Server
#vnc-server      5900/udp                # VNC Server
vnc1440 	5900/tcp 		# VNC and GDM
vnc800     5901/tcp            # VNC and GDM
cm              5910/tcp                # Context Management
cm              5910/udp                # Context Management

3. Make a configuration file for each display resolution

su -
gedit /etc/xinetd.d/vnc1440

Make the files look like this. substituting your resolutions for each one change "geometry" and "depth" to match each remote machine.

service vnc1440
{
disable = no
socket_type = stream
protocol = tcp
group = tty
wait = no
user = nobody
server = /usr/bin/Xvnc
server_args = -inetd -query localhost -geometry 1440x900 -depth 24 -once -fp /usr/share/X11/fonts/misc -securitytypes=none
}

then

su -
gedit /etc/xinetd.d/vnc800

service vnc1440
{
disable = no
socket_type = stream
protocol = tcp
group = tty
wait = no
user = nobody
server = /usr/bin/Xvnc
server_args = -inetd -query localhost -geometry 800x600 -depth 16 -once -fp /usr/share/X11/fonts/misc -securitytypes=none
}

and so-fourth


4. configure firewall (or turn off)

GUI method
Goto => System => Administration => Firewall
under the add ports tab
add 177, 5900, 5901, etc.
save configuration.

then I had to reboot to get everything working


5. install client on windows machine

on your windows machine download and install TigerVNC or Xming

Fedora 14 already has Remote Desktop Viewer in the applications menu, otherwise install another one of your choosing (if you want to connect from a remote Linux machine.

---------- Post added at 04:53 PM ---------- Previous post was at 04:27 PM ----------

note: Problems


1. I don't have sound on the remote machine

2. I cannot use su - while on the remote machine to run gedit, or any GUI programs. su - only works for commands in terminal.

3. cant mount removable storage if another user is logged in locally

4. when Xming or TigerVNC first make the connection, an error message "/usr/libexec/gconf-sanity-check-2 exited with status 256" comes up, but when you click close the log-in GUI comes up fine.

Any help with these would be appreciated.

[jpollard]

1) You won't. This would be up to the VNC to be able to forward pulse audio connections.
You also have problems with audio device access too. Including user mountable
media (such as audio CDs).
2) You shouldn't do that anyway. It will give the root password to anyone that wants it.
3) Another control issue - not available to anything but local use. Though
some form of forwarding might be possible, but it requires an additional
layer of lock control that doesn't exist.
4) Don't recognize that one. It almost sounds like you have two different
(and conflicting) configurations - XDMCP and VNC. There is a message
over on this where the protection code of the directory
/etc/gconf/gconf.xml.system is incorrect (it should be 755).

Congratulations. I didn't know XDMCP was still supported by gdm.

[wilson83]

You might be right about two services, during my quest to get it set up I tried a few different things.

How would I go about finding out if it was two conflicting services trying to answer the remote computer? and shut one of them down?

[jpollard]

I'm still looking at the VNC stuff - specifically the xvnc server - It appears
to be a local (to fedora) X server, in which case, XDMCP may not be
necessary... but still looking - I know xdm can handle multiple local
servers, I just don't know in what manner the xvnc operates. If it can
use the default domain sockets (specified in /tmp/.X11-unix/<display>)
then XDMCP isn't necessary. I also don't know yet if gdm/kdm can handle
multiple displays (haven't gotten to even looking there). That still leave
security up to the vnc protocol - and there are a lot of "it doesn't do that,
to get security use ssh and a tunnel" type of answer.

Did you check the access control over the /etc/gconf/gconf.xml.system
yet? I saw a reference that gave your error message when the access
protection was incorrect.

[wilson83]

Did you check the access control over the /etc/gconf/gconf.xml.system
yet? I saw a reference that gave your error message when the access
protection was incorrect.

that folder is empty. What do I do to check access control?

[smr54]

As far as I know, vnc can't handle remote audio. We had to look into that a few weeks ago (though it was Windows to Windows.)

[jpollard]

that folder is empty. What do I do to check access control?

The directory itself should be 755, with security label (you aren't
using so this doesn't matter) system_u:object_r:gconf_etc_t:s0

You can see everything with:

$ ls -lZd /etc/gconf/gconf.xml.system
drwxr-xr-x. root root system_u:object_r:gconf_etc_t:s0 /etc/gconf/gconf.xml.system