IP address space management

A hierarchical system of institutions manages the Internet pool of available IPv4 and IPv6 addresses.

History

• Jon Postel (1972–1998)
  • managed IP address allocations, protocol parameter registries, and DNS root coordination
  • from 1988 onward, these responsibilities were collectively referred to as the Internet Assigned Numbers Authority (IANA) in RFCs (beginning with RFC 1083)
  • Postel, working at the Information Sciences Institute, performed the IANA functions
• ICANN (1998–2016)
  • Internet Corporation for Assigned Names and Numbers (ICANN) was established in 1998
  • beginning in 1999, ICANN performed the IANA functions directly
• PTI (2016–present)
  • the Public Technical Identifiers (PTI) group was created as an ICANN affiliate as part of the IANA stewardship transition
  • PTI now performs the IANA functions under contract with ICANN

Obtaining a block of addresses

Subnets receive IP addresses through a global hierarchical system:

1. IANA (operated by PTI on behalf of ICANN):
   • delegates large blocks to regional organizations for further distribution
2. Regional Internet Registries (RIRs):
   • RIRs have been founded at different times during the rapid growth and globalization of the Internet
   • these include:
     • AFRINIC - African Network Information Centre (African region)
     • APNIC - Asia-Pacific Network Information Centre (Asia-Pacific region)
     • ARIN - American Registry for Internet Numbers (Canada, United States, and several Caribbean and North Atlantic islands)
     • LACNIC - Latin America and Caribbean Network Information
Centre (Latin America, Caribbean)
     • RIPE-NCC - Réseaux IP Européens Network Coordination Centre (Europe, Middle East, central Asia)
   • these organizations manage IP allocation within their regions
3. other address-distribution organizations:
   • RIRs give blocks of IP addresses to:
     • National Internet Registries (NIRs)
     • Local Internet Registries (LIRs)
     • Internet Service Providers (ISPs)
     • large organizations and network operators
   • these organizations then divide those blocks further
4. organizations and subnets:
   • organisations obtain a block of IP addresses from their ISP or LIR
   • the ISP assigns a portion of its allocated space
   • the organization then uses those addresses to create subnets to connect to the Internet