xhost question

Okay I have a lan set up at my house Its all behind a ipchain firewall
(RH 7.2 yes I know I should be using iptables). I'm getting tired of
running up and down stairs to get to my different computers and want to
simply export my display to my main computer. Trying to advoid typing
xhost +<hostname> for every computer in my house yet at the same time
I'm concerned that if I type xhost + that it will open my display to the
internet. So my question is does anyone know of the ipchain rule that
will prevent my display from going out? Or is this something I even have
to worry about?

Carl P.