I think you're correct about bootp. A bootp server app generally listens for a MAC broadcast which appears when another physically connected device sends a "bo

I think you're correct about bootp. A bootp server app generally listens for a MAC broadcast which appears when another physically connected device sends a "bootp request" into the network, so the bootp server can compare the MAC against its whitelist and assign its corresponding designated fixed IP address on the local network. Which IP address will then be remembered by the requesting device and is used from that point forward, not much differently than an address assigned by DHCP. Some hardware like early HP ethernet printers did not retain their assigned IP address through a power failure. So there had to be a functional bootp server app up and running before you powered up the printer or the printer's initial bootp request would go unanswered and it was no good to anybody.