The world in which IPv6 was a good design (2017)
IPv6&#x27;s biggest problem remains not that it&#x27;s badly designed (at least not nowadays, there were problems but they were solved ten years ago) but that millions of network engineers never bothered to look deeper into IPv6 than &quot;I don&#x27;t get it, this feels off&quot;.<p>You can&#x27;t make a backwards compatible &quot;IPv4 with more bits&quot; like people dream of. L2 routers and middleboxes would still need to be replaced, software would still need to be rewritten, nothing would be different. IPv4 changed how private networks worked because its first attempt at private networks failed.<p>People are stuck with the IPv4 mindset through a combination of lacking education (who even taught IPv6 when our current sysadmins were in college?) or assuming IPv4 is normal and well thought out. There are free guides, books, and playgrounds out there if you want to learn IPv6, so the education problem is one you can solve yourself. Realizing the flawed nature of IPv4 is harder.<p>I&#x27;ve come from IPv4 networking, but learning IPv6 later made me realize how silly old networks really are. DHCP is a hack to solve a design failure in IPv4 and SLAAC is a much better solution. Companies have started relying on awful hacks originating from when companies decided to staple features to a side effects of a generic address distribution protocol. ARP feels more like a placeholder that should&#x27;ve been included a layer lower or higher in the network graph, put in its own little place to solve the theoretical &quot;what if we don&#x27;t run IP over our switch&quot; problem that stopped being relevant decades ago.<p>As annoying as it may be, we live in an age where the OSI model with seven layers of networking protocols don&#x27;t exist. Token ring is dead, SCTP died in the womb, Ethernet II exist purely in theory. The world now runs on HTTPS on top of UDP or TCP on top of IPv6&#x2F;4, on top of some kind of wire that carries ethernet.<p>Ethernet now exists to support IP and vice versa in 99% of all use cases. TCP and UDP exist to serve HTTPS, or some legacy protocol that will be rewritten into HTTPS in the next ten years. WiFi and high-speed data networks came in as a whole new networking system and have turned out to be &quot;what if ethernet, but wireless&quot; with some control logic to make the wireless antennae talk. The OSI model and all the expansion and flexibility it provided simply died over a decade ago. Anything on top of the data link exists purely to support Ethernet + IP + HTTPS.<p>The migration path to IPv6 is now blocked by excuses. People pretended to care about servers not supporting IPv6 as the reason not to use but, but three or four different ways of providing backwards compatibility to all IPv4 clients were thought up and nobody actually asked for any of them. People complained that their data center provider didn&#x27;t support IPv6 but now that enabling IPv6 is just a single click in a web UI they don&#x27;t enable it anyway. People cared about the IPv6 privacy risks but never let go of that concept even after rfc4941 fixed that oversight. Companies like Microsoft and Github, too incompetent to set up a network that their dollar store competitors have supported for years now, have become something to point at and go &quot;see? we need those!&quot; as if NAT64&#x2F;DNS64&#x2F;464XLAT&#x2F;SIIT&#x2F;whatever haven&#x27;t been providing IPv4 compatibility for years now.<p>&quot;I don&#x27;t know enough about it&quot; and &quot;I don&#x27;t like it&quot; are perfectly good excuses not to enable IPv6 in your home network, but they&#x27;re not design flaws or protocol problems. If you&#x27;re willing to accept the packet maiming we have nicknamed &quot;NAT&quot; or even &quot;CG-NAT&quot;, you should feel refreshed at the sight of the plain and simple protocols IPv6 provides you with.<p>The way people talk about IPv6 now reminds me of the way people talked about HTTPS back when Let&#x27;s Encrypt started gaining popularity, and the way people dealt with systemd reinventing a better Linux management system. Grumpy people, clinging to what they know, delaying unavoidable change until the very last moment. You can be like the Dracut people running ipromiseiwillneverrunssl.com if you want, but it&#x27;s a losing battle.