If I understand certain parts of this article right, it suggests that IPv6 could in fact replace both the Network Layer (IPv4) as well as the Data Link Layer.

If I understand certain parts of this article right, it suggests that IPv6 could in fact replace both the Network Layer (IPv4) as well as the Data Link Layer. Is this correct? Has anyone put this into practice? Imagine that we lived in such a world: wifi repeaters would just be IPv6 routers. So would wifi access points. So would ethernet switches. So would SDN. ARP storms would be gone. "IGMP snooping bridges" would be gone. Bridging loops would be gone. Every routing problem would be traceroute-able. And best of all, we could drop 12 bytes (source/dest ethernet addresses) from every ethernet packet, and 18 bytes (source/dest/AP addresses) from every wifi packet. Sure, IPv6 adds an extra 24 bytes of address (vs IPv4), but you're dropping 12 bytes of ethernet, so the added overhead is only 12 bytes - pretty comparable to using two 64-bit IP addresses but having to keep the ethernet header. The idea that we could someday drop ethernet addresses helped to justify the oversized IPv6 addresses. It would have been beautiful. Except for one problem: it never happened.