It doesn't really work fine - you're just used to (or don't notice) all the ways that it doesn't work. We ran out of IPv4 addresses a while back, so we're doing

It doesn't really work fine - you're just used to (or don't notice) all the ways that it doesn't work. We ran out of IPv4 addresses a while back, so we're doing all sorts of stupid stuff like selling addresses, dynamic IPs, and address translation to distribute and squeeze more life out of the ones we have. This makes a lot of networks much more complicated than they really should be, and will only become a bigger problem as more devices come online. Universal IPv4 would enable some cool stuff, like giving every device on the planet a unique IP (or even several to increase anonymity), as well as vastly simplifying many common networking problems. Here's one example: Have you ever tried to use a home internet connection to host a server, say for home automation, file sharing or gaming? It's a huge pain for anybody who isn't network-inclined. By giving everything a unique IP, routing setup for this sort of thing becomes much easier since every device has a unique, static IP address that it can always be found at. Also, IPv6 has some security and encryption features that are not found in IPv4, which should basically end packet spoofing as an attack. It's also a bit faster too, because packet integrity isn't as rigorously checked and routing is simpler.