Running X windows applictions remotely from a Windows server

Question

This may seem like a strange question but it has some value for the project I am currently working on.

I have a Windows 2003 server running XMing (or Cygwinx). I am connecting to the server from Ubunutu using ssh with X11 forwarding enabled. When I launch any X application on the Windows 2003 server (such as xeyes) the application displays on the Windows server and not on the local Ubuntu machine.

Xming is a fully implemented X Server so I assumed it would support serving X applications to remote clients. Any suggestions why this is not working?

Answer 1

What is happening is the correct behaviour. The X Server (XMing) is running on Windows 2003 and serving the Xeyes application (a client) to you.

From Wikipedia with some edits ...

The X server accepts requests for graphical output (your W2003 server's display) and sends back user input (from your keyboard, mouse, or touchscreen).

X Window System's client-server terminology — the user's terminal being the server and the applications being the clients — often confuses new users, because the terms appear reversed. But X takes the perspective of the application, rather than that of the end-user: X provides display and I/O services to applications, so it is a server; applications use these services, thus they are clients.

Answer 2

Sounds like the ssh server is not acknowledging the X forwarding request. After you login, check the environment and you should see the DISPLAY variable set, indicating host and display (e.g. localhost:10); if that is missing, the X clients will use the default (e.g localhost:0) DISPLAY.

Also, the X server on the remote machine (the one ssh'd into) has no bearing on this, only the X clients installed there. When you ssh to the remote machine, your local Ubuntu host is the X server, accepting connections from the remote X clients.