[ale] [OT] Voicepulse question

[kaboom at gatech.edu (Chris Ricker)]

On Thu, 9 Dec 2004, Michael H. Warfield wrote:

> > I agree. IP addresses used with NAT are always private ... 10.0.0.0=20
> > /172.16.0.0 / 192.168.0.0
> > No point using "public" adddresses with NAT. In theory, however one could=
> =20
> > do so.
> 
> 	It's actually being done in practice in several very significant
> instances.  As far as "no point using", I don't know that I can argue
> one way or the other or both.
> 
> 	I know of several very large networks (an entire /16 for one)
> that "went NAT".  It was a fully assigned portable /16 address space
> (one of the old class B spaces) and they decided, for one reason or
> another (mine is not to judge), they wanted to no longer be "routable"
> and placed the entire /16 behind one or more NAT devices.  They then
> withdrew the BGP advertisement for that address space, so it no longer
> routes (or, at least, shouldn't).  Now, "no point", I can't say.  I don't
> know what they point for WANTING NAT might be.  Once you take it NAT
> though, you still probably want to keep those public addresses just to
> avoid the pain of renumbering an address space of 65,536 addresses.

Another usage of NAT with publically routable addresses is when you have a
situation like companies that are merging two different routable address
spaces into one and they don't want to renumber either existing network....

later,
chris