Hindsight is 20/20. It is easy to see now all the reasons IPv6 is not widely adopted, but back then they probably figured that adding more features would make i

Hindsight is 20/20. It is easy to see now all the reasons IPv6 is not widely adopted, but back then they probably figured that adding more features would make it more attractive or something. If I had a time machine and had to take a relatively naive crack at the problem, I'd make IPv6 really really simple: it'd just be IP-in-IP. On the internet you're routed with an outer address, and the local router forwards it using the inner address. Speaking v6 over v4 is free because v4 routers ignore the inner packet. Speaking v4 over v6 just doesn't include the inner packet. Other local hosts are just contacted through v4.