RFC 1884: “IP Model six Addressing Architecture” makes use of that phrase for a few bits at the conclusion of an IPv6 handle. (The quantity of bits seemed to fluctuate in a few various illustrations, but this identifier was ordinarily determined by the MAC-forty eight handle of the community card.) https://funbookmarking.com/story16906198/whats-my-ipv4-can-be-fun-for-anyone