This system-wide default is set in config files residing in /var/X11/xdm
You will probably need to edit the files:
Xsession
Xsession.dt
Xsession-remote
But to be sure, just grep for xhost, and change it to 'xhost -' where
needed.
On a slightly different beat, perhaps SGI will consider changes the
default settings, in either case I'd be interested in finding out why it
is the default behavior.
hope i helped someone......
-n
------Nafees Bin Zafar
<binzafn@musc.edu>
<nafees@cs.cofc.edu>
http://www.cs.cofc.edu/~nafees