6000 X11
 

it is mandatory for this port to be open when x is running ? can I be attacket throug this port ?
thanx

If you don't need it open you should close it. If you startx manually use this startx -- -nolisten tcp. There's also another way to close it but don't know because I use this method.

edit your /usr/X11R6/bin/startx file, and change the "serverargs=" to:
If you are running locally, you can do this safely.