Reviving ARPAnet

Frank McConnell fmc at
Thu Jan 18 16:24:55 CST 2018

> On Jan 18, 2018, at 9:39, Grant Taylor via cctalk <cctalk at> wrote:
> On 01/17/2018 11:33 AM, Noel Chiappa via cctalk wrote:
>> E.g. it probably only supports class A addresses, for instance, which is going to influence the code for picking the first-hop router.
> I was not aware that there was code that supported /only/ Class A (/8) addresses and /not/ Class B (/16) or Class C (/24) addresses.
> I /thought/ that everything was either classful (as in supports all three classes: A, B, and C) or classless (as in supports CIDR).
> Is my networking history missing something else?

In the course of this discussion I have been reminded that BBN did a TCP/IP for the HP3000 that ran under MPE IV. It is described in IEN 167 and if you read that carefully you will realize that they got started on MPE III; MPE message files (think record-structured pipes) first appeared in late MPE III but were not documented until MPE IV.

Trawling the Intertubes for, well, anything about this I turned up a sort of progress report.


It begins on page 66 of 81, on page 68 of 81 it describes changes to the routing table.  "Currently, this table has one entry for each of the possible 256 networks, and accesses are very fast." and I'll just leave you with that.

-Frank McConnell

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