How IP addresses were distributed globally

[mcseguy9]

Hey all, I wasn't sure which board to put this in but I think this one will work. I'm wondering if anyone knows of a resource online that explains how IP addresses, or the IP address space under IPv4, were allocated globally (by country). Each country has a certain number of IP addresses set aside specifically for them (that's my understanding), so my question is who determined that, how was it determined, etc? And has the determination been made for IPv6?

[Crimson Blonde]

Moved to Internet issues

[Tuttle]

The folks responsible for all that are the Internet Assigned Numbers Authority. Way back in the beginning, individual companies could go to IANA and get a block of either 256, 65536 or 16,777,216 addresses. Those were the only options available -- a company needing 300 addresses got 65000.

A couple of things have changed since then. The first is Classless Inter-Domain Routing (CIDR), which means that those old boundaries don't exist -- any power of two can be allocated as a block of addresses. The other is the birth of the Regional Internet Registries (RIRs) like ARIN (North America), RIPE (Europe, Middle East), APNIC (Asia Pacific), LACNIC (Latin America) and AfriNIC (Africa). IANA now only delegates blocks to the RIRs, who then subdelegate in their region.

The current IANA IPv4 allocations are described here. The IPv6 situation is described in a handful of documents linked to from here.