Tuesday, March 4, 2003

Laptop partly broken, Xdmcp to the rescue

My laptop took a header onto the floor and the corner of the case is
smashed up. If it is pressed back into shape, the monitor turns off
-- this makes it hard to type on.



Since the desktop configured just the way I like it as well as a
chroot debian/unstable environment for building debian packages I
wanted a way to get to the laptop from my other work (Compaq Deskpro
EN running Red Hat 8.0) and other home systems (specifically my wife's
Microsoft Windows 2000 laptop + cygwin).



The solution was to enable Xd
mcp
on the laptop and then connect to
it from the other system's X servers. Here are the steps.




  • On the laptop which uses kdm, edit /etc/kde2/kdmrc and look for
    the [Xdmcp] section and enable it. The line looks like this



    [Xdmcp]
    ...
    # Whether KDM should listen to XDMCP requests. Default is false for Debian.
    Enable=true
    ...





  • Now edit /etc/kde2/kdm/Xaccess to allow access. Uncomment the two
    lines that look like this:




    ...
    * #any host can get a login window
    ...
    * CHOOSER BROADCAST #any indirect host can get a chooser
    ...


    You can tighten up security by enumerating all the systems you want
    access from. Since both of the networks my laptop connects to (home
    behind a NATting firewall and work's corpnet) are secure enough for me
    so I didn't bother.




  • Now restart kdm on the laptop, "/etc/init.d/kdm restart"






  • From the linux desktop, startup X and have it connect to my laptop's XDMCP:


    X -broadcast -query mylaptop.name :1

    And in a few seconds there is the familar KDM login on ALT-F8.



  • From the Microsoft Windows 2000 desktop that has cygwin installed,
    startup X and have it connect to my laptop's XDMCP:


    X -broadcast -query mylaptop.name :1

    And in a few seconds there is a window that contains the
    familar KDM login.



  • Performance is acceptable across WiFi.

1 comment:

  1. Thanks marc for your bloc. I think the section about the /etc/kde2/kdm/Xservers file is missing. without an entry in the form IP/Servername:0 foreign for each terminal the configuration will not work.

    Cheers, Mark.

    ReplyDelete