Sam Moffatt

Whilst not installed by default with MacOS X 10.4.x, X11 is the popular X windowing system familiar to those who use Linux.

What you may not realize is that this can be used with a terminal to provide an XDMCP login screen to your Linux boxes and not just SSH forwarding.

Xquartz -query 10.0.0.3 :1

This brings up on your desktop hopefully a login screen to your favourite Linux server (might want to replace 10.0.0.3 with the name or IP address of your target) if XDMCP is configured properly). If it doens't there are a few things to check:

• Check that XDMCP is actually enabled on the remote machine, checkout the documentation for your favourite login manager for this. On SuSE machines I believe this is enabled by default. I'm a Debian/GNOME/GDM person, and you can use the gdmsetup tool (needs root).
• If you've enabled any sort of firewall this will be blocking the connections - but not on the outgoing side but the incoming. The evidence for this is a grey background with nothing connecting (you may need to enable fullscreen in the X11 application preferences). If you're using the internal firewall, go to System Preferences > Sharing > Firewall > New. From here select port name 'Other', enter TCP port 6001 and enter the description 'X Server'. Try again.
• You may not have X11 installed. Its on your supplied DVD under Bundled Software :)