In the various examples of how hosts are specified, for durus, scgi,
etc, for a QP site, I see the following 3 values used seemingly
interchangeably to specify the same local host:

   ''
   'localhost'
   '127.0.0.1'

Is there an effective difference between these 3? What is it?

I was under the impression that specifying 127.* implies an internal
local network, and should not be seen from the outside, but it seems to
be anyway (at least on the freebsd machine I am testing this on).

What I am after is to hide from the outside the durus and scgi ports on
the same localhost. Is there a way I can declare this here? How can I
achieve this otherwise?

mario