[124600] in North American Network Operators' Group
Re: legacy /8
daemon@ATHENA.MIT.EDU (Steven Bellovin)
Fri Apr 2 19:08:47 2010
From: Steven Bellovin <smb@cs.columbia.edu>
In-Reply-To: <courier.000000004BB671E2.00007B21@blargh.com>
Date: Fri, 2 Apr 2010 19:03:07 -0400
To: Andrew Gray <3356@blargh.com>
Cc: NANOG List <nanog@nanog.org>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
On Apr 2, 2010, at 6:38 26PM, Andrew Gray wrote:
> Jeroen van Aart writes:=20
>> Cutler James R wrote:
>>> I also just got a fresh box of popcorn. I will sit by and wait
>> I honestly am not trying to be a troll. It's just everytime I glance =
over the IANA IPv4 Address Space Registry I feel rather annoyed about =
all those /8s that were assigned back in the day without apparently =
realising we might run out. It was explained to me that many companies =
with /8s use it for their internal network and migrating to 10/8 instead =
is a major pain.
>=20
> You know, I've felt the same irritation before, but one thing I am =
wondering and perhaps some folks around here have been around long =
enough to know - what was the original thinking behind doing those /8s?=20=
> I understand that they were A classes and assigned to large companies, =
etc. but was it just not believed there would be more than 126(-ish) of =
these entities at the time? Or was it thought we would move on to =
larger address space before we did? Or was it that things were just =
more free-flowing back in the day? Why were A classes even created? =
RFC 791 at least doesn't seem to provide much insight as to the 'whys'.=20=
Many large companies found that class A nets weren't very useful. =
Multiple levels of subnetting didn't exist, which meant that you =
couldn't assign a /16 to a location and a /24 to each piece of thick =
yellow cable within the location, for example.
AT&T got 12/8 moderately early. We realized we couldn't easily use it, =
and offered it back in exchange for the equivalent in class B space. =
Postel gave us the latter (135/8), but told us to keep 12/8 -- other =
people were discovering the same problem, so there was little demand for =
class A networks. (This was circa 1987, if memory serves, and possibly =
a year or two earlier.)
--Steve Bellovin, http://www.cs.columbia.edu/~smb
