Can we go back in time and hit the designers of IPv6 upside the head? The decision not to make IPv6 backwards compatible, the belief that a beautiful new standard could magically replace something already so widespread... "Naive" is an inadequate word. We are still futzing with the transition 3 decades later, with no end in sight. Grrr, grumble...
These arguments always boil down to these two: "Please just try to fit more than 4 billion numbers into 4 bytes" -- this is mathematically impossible. "Just extend the address size" -- this is an entirely new protocol by the definition of IPv4, which uses fixed-size addresses. The reason for the slow IPv6 adoption is that there was no financial or business pressure. While IPv4 is ubiquitous, nobody individually feels…
NO!!!
this is what the parent comment meant about ipv6 design. Add an octet and that's it. Same protocol with same rules just a bigger address.
It may be a different version of IP but the protocol and supporting protocols like ARP and DHCP just need to support the new IP.
The reason IPv6 failed is the same reason why when new devs join a team, they find how everything is wrong and try to fix it all and leave a bigger mess than what they started with. You solve problems one step at a time. Overhauls are only justified when your objective is specifically to improve the whole system.
"The reason for the slow IPv6 adoption is that there was no financial or business pressure."
That is only part of the reason. The other part is it is a pain to use, there is no way to use it without also supporting v4 and on top of that you have to learn and adapt other new protocols, addressing schemes, gotcha's and much more.
Just add a freaking octet!