[ih] Some Questions over IPv4 Ownership

[Louis Mamakos]

Two other random thoughts on this topic:

For a while, the generalized subnet architecture "supported" non-continguous
subnet masks to distinguish the network part from the host part.  I don't
know what the driver for this was.  Maybe IP address <-> ARPANET host/imp
mapping [10.host.X.imp] where the X octet was used as a "logical host" behind
some sort of multiplexing device or gateway/router.   A subnet mask 
might be 255.255.0.255 in that scenario.

Of course, when CIDR came on the scene, a strict prefix approach was adopted.
Actual deployment of CIDR was serialized behind the BGP3->BGP4 deployment
activities on the major backbones at that time.

Louis Mamakos

On Oct 13, 2010, at 1:03 PM, Noel Chiappa wrote:

>> From: Craig Partridge <craig at aland.bbn.com>
> 
>> I always viewed CIDR as a logical extension of subnets (the ability to
>> own a A, B or C address and break it up into smaller networks within
>> your organization).
> 
> Also (and even more so) Roki's then-well-known work on supernetting, which
> everyone keeps forgetting (hint, hint :-)... See this message:
> 
>  http://www.ietf.org/mail-archive/web/ietf/current/msg24111.html
> 
> and following.
> 
>> And it is clear who invented subnets -- that was Jeff Mogul (that's my
>> memory and RFC 917 [published 1984] supports that recollection).
> 
> Ahem. IP subnets had been in use at MIT for many years - see, for instance,
> IEN 82, February 1979, "LCS Net Address Format". Jeff was an undergrad at MIT,
> and 'merely' (an invaluable service, to be sure) documented basically what we
> were already doing, as one entry in the 'subnet sweepstakes' (see also RFC's
> 925, 932, etc), once it became clear that other sites were going to run into
> the same situation that MIT had been in for many years (too many LANs at the
> site, the 'main' routing tables could not - and needed not - have an entry for
> each one).
> 
> I should give a further 'shout out' to David Moon, who is the origin of the
> 'subnet mask' part of subnetting (he mentioned the idea in email to me, and I
> promptly glommed onto it, and passed it on to Jeff).
> 
>> In the context of Noel's note, Jeff was at Stanford at the time (I
>> can't recall in what capacity).
> 
> Grad student.
> 
> 	Noel
>