Everything I've ever read about loopback, and regarding the merits of using or not using it, seem very vague. I'm specifically referring to Firefox here, but I'm sure other browsers use it as well. What exactly is it? What is it's purpose? Should I be allowing it? My general rule of thumb is that if something doesn't appear necessary on my box for proper functionality... I don't allow it. But I realize that sometimes you can be harming yourself while being oblivious to it. Everything may SEEM to be fine on the surface, but it isn't. And Firefox "seems" to work just fine without allowing a rule for loopback. But... is it really? Thanks for any insight.