>You cannot do this with IPv4 either. Routing has to work. It works for both IPv4 and In But if you are saying, you add 2-3-4 layers of NAT, this is just crazy.
Is it? I'm behind two layers of nat and everything works fine.
That NAT "does not work" is an old myth that certain people love to use. If you show it does work, their final reply is always: but inbound connections are hard.
I do not know who needs inbound connections to all of their devices in a corporate network, nor at home, since we solved that shit long time ago.
It only counts as working if you are ok with a giant pile of hacks and pain. Ever had to debug NAT-related SIP issues? Not fun. A lot of protocols fell out of favor, because they poorly interact with NAT (and stupid corporate firewall rules on the other hand so everything gets tunneled via https now..).
And wanting inbound connections is really not that strange a request. Maybe I want to host some website at home? How about a weather station/other IoT..
How about multiplayer gaming?
There are so many things that would benefit from being able to poke some holes in the firewall. With carrier grade NAT becoming more and more common you can forget about that, since you have no control over their infrastructure to forward any ports.
I do not know who needs inbound connections to all of their devices in a corporate network, nor at home, since we solved that shit long time ago.