v4 doesn't even manage one IP per person. It's fundamentally completely insufficient in a world with personal computing devices. Even if you declared every sing

v4 doesn't even manage one IP per person. It's fundamentally completely insufficient in a world with personal computing devices. Even if you declared every single IP in v4 to be wasted and demanded we repurposed them all, it wouldn't be enough to fix that. The multicast and reserved blocks total 32 /8s. Before IANA runout, we were going through over one /8 per month, so this would represent less than 2.5 years of allocations. We've already spent decades buying more time for people to migrate to v6; we don't need another 2.5 years that people will just immediately squander. NAT is not in any way a feature. I'll admit it can be a useful tool in your toolbox sometimes, but otherwise it's just a completely unnecessary complication that breaks things and wastes time and effort. It's not something to be building the Internet on. You want each device to get an IP and you don't want two devices to have the same IP, because that's how machines on the Internet send packets to each other -- which is the entire point of having the Internet at all. > All of "the global internet" is in 2002::/16, which effectively gives 32 bits of assignable space. Exactly the same as IPv4 [...] the assumption that all routable prefixes are in 2001::/16 as specified Global allocations are actually coming from the entire of 2000::/3, not 2002::/16 or 2001::/16 (and there's another five untouched /3s in case we need them). So far about 0.2% of it been allocated to RIRs, and most of that RIR space has not yet been allocated to anybody. We're clearly not exhausting it at anything like the rate of v4. v6 is less complex than v4 in practice due to not needing NAT, and gains us far more than you're thinking. A /48 contains 65k subnets of effectively infinite hosts each, which is similar to a /8 but with no limit on hosts per network, and there are something on the order of a trillion of them in total rather than 256 of them.