Re: Mapping plan
and why the original transition model was pure dual stack.
Things got complicated largely because of reluctance in the industry to adopt this simple transition plan.
And the fact that the original IPv6 model didn't work in the real world.
Security? Nah - you don't need that.
IP address auto-allocation? All handled. Except when it isn't.
In short, all the modern OSes have been IPv6-enabled for years. But we are still not seeing mass takeup because it still doesn't (despite all the tweaks and kludges) work well in the real world.