The question above for the most part, been reading up on it. Also want to it for learning purposes.
Wait, ipv6 doesn’t require port forwarding to expose something to the internet?
Port forwarding is exclusively a NAT phenomenon.
In IPv6 every device should in theory have a public address - just like how every computer had a public IPv4 address back in the 1980s ~ 1990s.
However, most sensible routers will have a firewall setup by default that blocks all incoming connections for security reasons. You still need to add firewall rules.
There’s no “should in theory”. It’s only a possibility due to sheer number of possible combinations. No one was ever going to make every device public. It makes absolutely no sense. Why would your company’s printer be online or isolated networks or VPNs? There’s no point.
IP addressing is just a way to give a globally unique number to each device. It’s just a number.
And there wasn’t a real public/private distinction when the Internet was still in its infancy. Printers were indeed given “public” addresses because people needed a number for it.
If you don’t want your printer to be reachable by the public Internet, use a firewall to block outside connections. If you can use NAT, you certainly can use a firewall. Heck, they are almost the same thing if you have been using the Linux kernel (iptables/nftables handle firewalling and masquerading with the same tool!)
Routability is not the same as reachability. With NAT transversal you can reach my “private” hosts all the same, although you can’t route to me because I don’t have a public address.
