On Apr 2, 2010, at 6:38 26PM, Andrew Gray wrote:
> Jeroen van Aart writes:
>> 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.
>
> 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?
> 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'.
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
