Laptop as a X-station Using xdm

[tony j. podrasky]

I have a desktop tower running Linux.

I used to have an X-station server that would
boot (tftp) off the tower (across the network)
and act like it was part of the tower.

I'd like to take one of my Linux laptops and
set it up so that it does the same thing.

The reason being that I want to be able to use
the laptop as if it were a part of the tower, so when I start an x-session I log into the tower and everything acts just like I'm on the master console.

I'm running XDM on the server.

QUESTIONS:

o Has anyone tried using a laptop as an X server?

o Is there a program that I can fire-up that will do what I want?

Any ideas will be appreciated.

regards,
tonyp

[Steven E. Protter]

Shalom.

o Has anyone tried using a laptop as an X server?

Yes. I install Linux and use ssh -X to log on to HP-UX and Linux.

e

o Is there a program that I can fire-up that will do what I want?

See previous answer.

ssh -X hostname gnome-terminal

Lets me run anything I want on Linux server with the laptop as the X server.

SEP

[tony j. podrasky]

Hi Steven;

Thanx for the response.

Yes, that will bring up an X-session on the
laptop - but what I want is the laptop to act
just like the master console - where the
xdm login screen will appear and you enter
your login and password and after successfully
logging in you will be presented with your
home environment.

regards,
tony

[Alan_152]

I've used PilotLinux (http://www.pilotlinux.nl/) to boot up a computer/laptop as a thin-client simulator.

Otherwise, you can configure XDMCP on your tower to send out a full desktop to an X-server on your laptop. http://www.starnet.com/xwin32kb/How_do_I_enable_XDMCP_on_my_Unix_machine/

[Matti_Kurkela · Accepted solution]

This is actually fairly easy to do. It's mostly a matter of starting the X server on the laptop with some non-default options.

On the tower, check the /etc/X11/xdm/Xaccess file, read the (very verbose) comments in that file and make sure it allows XDMCP connections ("Direct queries", in xdm terminology) from the laptop.

On the laptop, disable xdm and any other systems that would start the X server automatically.

Then log on the laptop using the text console, become root and start the X server on the laptop with the command:
X -query

This command should immediately display the xdm login box of the tower on your laptop.

Note that the X protocol handles only the screen, keyboard & mouse: to use any other facilities of the laptop, you must set up additional services. For example: to get sound, set up the laptop to run one of the various Linux sound servers. When running a sound-using application on the tower, set it up to use the sound server on the laptop.

Be aware of the following:
This is technology of the previous century, of the era where people still trusted each other implicitly on the networks.
_Your connection is not encrypted nor otherwise meaningfully protected in any way._
With a minimum of preparation, anyone with access to your network could do various nasty things to you.

Sending the display of a joke program (google for xroach or xsnow) onto your screen from elsewhere is one of the classic X tricks. If someone can snoop the network traffic, he can easily reconstruct your display image. An intruder could also send onto your screen an invisible, borderless full-screen window that passes all keypresses and mouse-clicks through to the windows under it... but also allows the intruder to get all your keyboard and mouse events.

MK

[tony j. podrasky]

Hey Matti!

That did it!

Earlier I had tried the X -query but didn't know that I need to have the tower's name in there.

When I did the X -query m2404txp it came up in about 2 seconds! I logged in and all worked fine. Then I signed out and the login window from the tower came back!

I'm at home on my own network so no problems with security.

To the other posters - thank you for your time and ideas.

I did download a program called pxdmcp. I got it to connect to the tower (host) but it disconnects saying that it can't get ahold of the display.

regards,
tonyp

[tony j. podrasky]

Matti provided the solution.