The IPv6 Transition

People posting have mentioned that IPv4 is working for what they use the internet for. But of course it is. When NATs has been required for your whole life, how could the internet have built features that needed p2p routing? Just convince businesses to build something that requires special router configuration? And still wouldn’t work on phones or with ISPs that require CG NAT? You got what worked out of the box. You obviously couldn’t use what didn’t exist.

Why do people assume IPv6 means "easy p2p"?

Even if NAT will be gone one day, the stateful firewalls won't. Every every home router would still ship with "deny all incoming" by default, and every corporate network would have the same setting as well.

Same as IPv4, IPv6 serving would still need registration with border device, either manual by user, or via UPnP-equivalent.

With how trivial generating new addresses in IPv6 is, it'd be cool to have a host block all incoming traffic on its own and have each service that deserves to be reached over the listen on an address unique to the service.

> have each service that deserves to be reached over the listen on an address unique to the service

It’s already a thing. These unique per-service addresses are called “ports” in IP protocol.

Hosting service A shouldn't mean that every user of service A can also figure out you host C, B and D.

Also, the IP protocol does not care about ports at all. Ports are a thing for UDP and TCP.

> Also, the IP protocol does not care about ports at all. Ports are a thing for UDP and TCP.

You're right, they are one level above.

> Hosting service A shouldn't mean that every user of service A can also figure out you host C, B and D.

It how are ports on a single IP address essentially different from multiple IP addresses within a subnet?