Internal Address Space

[Robert Elz]

    Date:        Fri, 3 May 2002 16:14:10 -0400
    From:        "David F. Newman" <dnewman@maraudingpirates.org>
    Message-ID:  <200205031614.10792.dnewman@maraudingpirates.org>

  | Actually it has always seemed logical to me to use public address 
  | behind a firewall.

It is.   After all, private address space is a comparatively recent
addition, before that everyone used public address space (either
legitimately obtained, or "borrowed").

  | It was the networking group at my company that informed 
  | me that private space is used behind firewalls just as a matter of  course.

For IPv4 these days it is - because the addresses are scarce, and
using them to number things that cannot be reached from outside is
just wasteful.   It used not to be that way, and for IPv6, never
needs to be that way.

  | My own ISP gives me one address and so I use a private address space 
  | inside my firewall.

Same thing, they're just only allocating the minimum that they can get
away with, so they have addresses to allocate to others (and besides, it
means that they can charge you more, for nothing really, if you want more
public addresses).

  | I was thinking that if my firewall tunnels to 6bone
  | then my inside machines could have private IPv4 addresses and public 
  | IPv6 addresses.

Yes, that is not at all uncommon.

kre