Nick Hilliard wrote:
E.g. using mcast for address resolution because large flat l2 networks were the order of the day,
It was and still is trivially obvious that automatic address resolution over large flat l2 does not scale. Configuring virtual all-host-mcast in large flat l2 for automatic address resolution needs static address resolution information, which is not automatic.
that client self-selected addresses should be the only game in town for auto-addressing
Using lengthy MAC addresses for that purpose was tried in XNS. But as it was so annoying, it was totally abandoned at the time IPv4 was widely developed. Though AppleTalk was still using a single byte for that purpose in SOHO, DHCP was already performing better everywhere including SOHO.
that extension headers were a great idea,
IPv4 optional header was totally operationally denied a lot before that. Masataka Ohta