A regional Internet registry (RIR) is an organization that manages the allocation and registration of Internet number resources within a particular region of the world. Internet number resources include IP addresses and autonomous system (AS) numbers.
The regional Internet registry system evolved over time, eventually dividing the world into five RIRs:
- The African Network Information Center (AFRINIC) serves Africa
- The American Registry for Internet Numbers (ARIN) serves Antarctica, Canada, parts of the Caribbean, and the United States
- The Asia-Pacific Network Information Centre (APNIC) serves East Asia, Oceania, South Asia, and Southeast Asia
- The Latin America and Caribbean Network Information Centre (LACNIC) serves most of the Caribbean and all of Latin America
- The Réseaux IP Européens Network Coordination Centre (RIPE NCC) serves Europe, Central Asia, Russia, and West Asia