Re: Private use of non-RFC1918 IP space

[TSG <tglassey () earthlink net>]

Joe Greco wrote:
> > On Feb 2, 2009, at 10:57 AM, Jeffrey Ollie wrote:
> >     
> > > On Mon, Feb 2, 2009 at 9:48 AM, Trey Darley <trey () kingfisherops com>  
> > > wrote:
> > >       
> > > > Some colleagues and I are running into a bit of a problem. We've been
> > > > using RFC 1918 Class A space but due to the way subnets have been
> > > > allocated we are pondering the use of public IP space. As the  
> > > > network in
> > > > question is strictly closed I don't anticipate any problems with  
> > > > this as
> > > > the addresses would be unambiguous within our environment. I'm  
> > > > curious if
> > > > anyone else is doing this.
> > > >         
> > > I'd recommend against it, because even though the network is not
> > > connected to the Internet now you never know what the future holds.
> > > Even if it's never connected there are always things that seem to pop
> > > up and cause problems.
> > >
> > > Also, if you're address allocation policy has been so badly managed
> > > that you've run out of space in 10.0.0.0/8 adding more IPs to the pool
> > > isn't going to help for very long.
> > >       
> > It will if you manage it better.
> >
> > Fortunately, there's a /12 and a /24 still left.
> >     
>
> And a /16.  (What's the /24?)  And possibly some other space that is
> reserved-for-other-purposes.
>
>   
> > A /12 is more space  
> > than 99.99% of the networks on the Internet need, so why wouldn't that  
> > suffice instead of using "real" space.
> >     
>
> If you absolutely, positively *had* to allocate another /8, it'd probably
> be best to look through Class A space for networks that are not likely to
> ever appear on the Internet.  ISTR a bunch of them are assigned to the US
> military, for example.
>
> ... JG
>   
For which the unauthorized use of could be construed as a military 
attack if those pirated addresses ever appear on the open Internet from 
this ISP... No that's also a really bad idea. I find it really 
troublesome to believe that the subnetting on a site was so complex that 
it ate an entire /8. What I am betting is that for some reason that ISP 
wants its addressing to be totally flat and not replicated.

Todd