North American Network Operators Group

Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical

Re: IPv6 news

  • From: Todd Underwood
  • Date: Wed Oct 12 17:07:46 2005

ras, all

On Wed, Oct 12, 2005 at 04:38:53PM -0400, Richard A Steenbergen wrote:

> of its legacy unused /8 allocations. I'm certain that someone with some 
> historical BGP data could put together an analysis of who has not used 
> their IP allocations at ALL within the last few years, still more low 
> hanging fruit which we can take care of now. Of course, the last time I 
> mentioned an unused /8 which should have been returned years ago on this 
> list, the party in question started announcing it in BGP the next day.

the problem here is this:  there is no guarantee that prefixes that
are never seen in global tables are not used and deployed.  for
example, the US DoD has quite a lot of address space (pre-rfc-1918)
deployed onto the SIPRNet, i believe.  this is not routed to the
public internet, but is in use.

an argument could be made that one could ignore that space, since it
is never intended to route publicly, but intentions change and
address/prefix conflicts are bad.  

by saying this i don't intend to disagree with the general premise:
there are tons of genuinely unused prefixes out there.  the point is
just that i doubt that there is an automated way to determine exactly
which ones they are.

todd underwood
director of operations & security
renesys - interdomain intelligence
[email protected]