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Re: Whoa; the 3 network?

  • From: Eric Osborne
  • Date: Wed Dec 31 12:58:00 1997

> % I did a casual sequential-countup scripted "ping -a" on a small slice
> % of 3.0.0.0, and found almost no working domains within this address
> % space.
> [stuff deleted here]
> >-- End of excerpt from Randall Pigott
> 
>   Ping turns out to be a remarkably ineffective tool at measuring
> the utilisation of addresses or accessibility of hosts.
> 
> Ran
> [email protected]

True, but "sh ip bgp" is useful.  And with tools like the looking glass, 
there's no room for excuses like "I'm not on a BGP router" or whatever.
>From my upstreams (BBN, UUnet, Sprint), I only see announcements for the
following traditional Class A's:

{ 4 6 9 12 13 15 16 17 18 20 24 30 32 33 35 36 38 40 44 53 55 57 62 } = 23 used

(I'm assuming that the 3.156.20.0/24 from Telstra is bogus)

That leaves (128 - { 127 10 1 2 } - 23) = 101 Class A addresses that are 
unadvertised.  Or, to put it another way, 1,694,498,816 available IP addresses,
more or less.  While I'm sure there's a legitimate reason for some of this
to be allocated and not advertised all the time, it sounds to me like there's
a big waste of space here.  I may be missing a few more reserved nets 
and whatnot, but either way you slice it that's a lot of address space.

"But wait!" I hear someone cry.  "I own one of those Class A's that you don't 
see advertised, and I may want to eventually connect my web server to the 
Internet some day!"  OK.  Fair enough.  Why don't you keep x.0.0.0/18, and give 
the rest back?  Or find yourself a NAT box?  Or (etc...etc...all been said).

This is assuming that you only own one netblock, and aren't using another
block for your corporate 'Net gateway.

So how do we reclaim the unused address space?  I dunno - very carefully?  
Approach all 101 unused Class A contacts, let them know that they'll have to
justify their use of space sometime in the next six months.  See if you can
find one that completely went out of business.  Then make sure that people 
like us, that may filter out BGP based on block/mask combinations are aware of
the new allocation scheme.  Give out the newly reclaimed Class A until it's
almost gone, then start again.  

Or has this been done?  I seem to remember something on this list a few weeks
ago about unused address space (maybe in the beginning of this whole 3.0.0.0
thread).  If it has been done, why didn't it work and what needs to be done
differently?  (And I mean that constructively.)




eric