Internet Assigned Numbers Authority
RIRs split their address pools into smaller chunks and give them to Internet service providers in their region. IANA assigns addresses with a /8 prefix for IPv4. It also assigns IPv6 addresses with /23 and /12 prefixes. These IPv6 addresses come from the 2000::/3 IPv6 address block. Because IPv4 addresses have run out, IANA does not assign them any more.