[ih] History of duplicate address tests

[John Gilmore]

John Kristoff via Internet-history <internet-history at elists.isoc.org> wrote:
> I'm curious to know about the earliest of duplicate address detection
> mechanisms.

Were there any duplicate address detection methods used in the 3-megabit
Experimental Ethernet?  As I recall from the early 1980s on Stanford SUN
workstations, the 8-bit addresses used to identify nodes were configured
by DIP switches on the interface board, so there was a significant
chance of mistakenly configuring a duplicate address.

April 1984's RFC 895 describes how IP datagrams are carried on
Experimental Ethernets.  It provides no duplicate detection, merely
suggesting (in those days of unlimited IP address space), "The easiest
thing to do is to use the last eight bits of host number part of the
Internet address as the host's address on the Experimental Ethernet.
This is the recommended approach."

Perhaps PUP or other early Ethernet protocols did duplicate address detection?

	John