> The address space is still enormous: a couple billion for every currently living person (yes, I know allocating isn't 100% efficient, but even at 0.001% effic

> The address space is still enormous: a couple billion for every currently living person (yes, I know allocating isn't 100% efficient, but even at 0.001% efficiency, that's still tens of thousands per capita). The biggest problem with IPv4 is subnetting inefficiency. IPv6 had this large address space precisely because they wanted to have smallest subnet so big that we don't have to worry about it. This is why it is told, that in IPv6 you don't allocate IP addresses, you allocate subnets.