Xhost + : unable to open display ":0.0", Please help

Question

Hello folks, I am running into problem with displaying X window on pc.
When I run xhost +, am getting 'unable to opne display ":0.0"
I was able to display window on another sun machine but not on the pc.
I beleive problem starts with the xhost + which produces error.
Can you recommend something.

Answer 1

If you are trying to display an X window on a PC, then you need an X server on the PC- even if the application you are trying to run is executing on the sun server. PC's (presuming Windows 2000, XP or later) don't have an X server included. Sun and Linux bundled X windows clients and servers (and ssh clients and sshd servers) so they work a lot easier. X windows reverses what is normally considered a client and server.
I find most X display things work better if you can tunnel the display back over SSH. Typically on a sun client machine you should "ssh -X sunserver", run the app on the sun server, and the X display would get redirected back to sun client. Otherwise you need to run xhost on the X server machine (i.e. the client machine you are on) and use "DISPLAY=" or "setenv DISPLAY" on the X client (i.e. the sun server) to redirect display.
If you get Xming installed on your Windows PC, it includes ssh client functionality and a wizard that you can run on your PC get launch the X app on the sun server and tunnel it back. In theory, if the X server is running on the PC you should be able to set it accept X connections and then on the Sun server type "set DISPLAY=mypc:0.0;export DISPLAY" to redirect the X display- but that hasn't worked so well for me.
Cygwin also includes an optional X server for Windows- however, you seems to need be an admin-equiv for that to work. But I think it includes an X-term app that handles "ssh -X" for X redirection.
Attachmate (formery WRQ) has a commerical ssh/X package for Windows but I could never get X tunneling over SSH to work.