If every unit is to have a unique address, e.g. the MAC addresses contained on Ethernet circuits, you have to have a pretty large range. Now, any scheme will demand some sort of ARP, but keep in mind how large the MAC address range is. If it's internally stored, it places a significant burden on manufacturing, as they have to track which addresses have been used and ensure they're NEVER used again.

I agree, though, that if you decide to use that scheme, it IS simpler for the end-user. It places a bit more load on the ARP, but that's probably tolerable so long as the working address will fit in one register. It increases the initialization time from several seconds to many hours, though, since it takes a while for the master to poll 2^64 addresses, waiting for all responses, then recording and tabulating the non-nil ones.

Clearly that would force some more complex protocol, with the baggage that brings with it, as polling is, under such conditions, far too time-consuming.

RE