On Sep 17, 2010, at 5:20 46PM, Bill Stewart wrote:
> Sorry, fat-fingered something when I was trying to edit.
>
> On Fri, Sep 17, 2010 at 2:12 PM, Bill Stewart <nonobvi...@gmail.com> wrote:
>> On Tue, Sep 14, 2010 at 6:51 PM, Steven Bellovin <s...@cs.columbia.edu>
>> wrote:
>>> No, they bought AT&T, which [...] But yes, SBC is the controlling piece of
>>> the new AT&T.
> Most of the wide-area ISP network is the old AT&T, while
> much of the consumer broadband grew out of the SBC DSL side.
Yup.
>
>>> As for the two /8s -- not quite. Back in the 1980s, AT&T got 12/8. We
>>> soon learned that we couldn't make good use of it, since multiple levels of
>>> subnetting didn't exist. We offered it back to Postel in exchange for
>>> 135/8 -- i.e., the equivalent in class B space -- but Postel said to keep
>>> 12/8 since no one else could use it, either. This was all long before
>>> addresses were tight. When AT&T decided to go into the ISP business, circa
>>> 1995, 12/8 was still lying around, unused except for a security experiment
>>> I was running.* However, a good chunk of 135/8 went to Lucent (now
>>> Alcatel-Lucent) in 1996, though I don't know how much.
>
> The AT&T bits kept some fraction of 135; I don't know how
> much without dredging through ARIN Whois, but at least 135.63/16 is on
> my desktop.
I know -- that's why I wrote "a good chunk", but I sure don't know who got
what. (FYI, I'm still a very part-time AT&T employee.)
>
> If I remember correctly, which is unlikely at this point,
> 12/8 was the Murray Hill Cray's Hyperchannel network, which I'd heard
> didn't know how to do subnetting except on classful boundaries, so it
> could happily handle 16M hosts on its Class A, and in fact only had
> two or three.
Good point. I don't remember what time frame that was true, though. I'm
certain about why Mark Horton got 12/8 and 135/8, but I don't remember the
years, either.
--Steve Bellovin, http://www.cs.columbia.edu/~smb
