What is Regional Internet Registry?

A Regional Internet Registry (RIR) is a nonprofit organization responsible for the administration, allocation, and registration of Internet number resources within a defined geographic territory. There are five RIRs: the American Registry for Internet Numbers (ARIN) for North America; the Réseaux IP Européens Network Coordination Centre (RIPE NCC) for Europe, the Middle East, and parts of Central Asia; the Asia-Pacific Network Information Centre (APNIC) for Asia and the Pacific; the Latin American and Caribbean Internet Addresses Registry (LACNIC) for Latin America and the Caribbean; and the African Network Information Centre (AFRINIC) for Africa. Each RIR operates independently but follows global policies developed through the bottom-up, consensus-driven process of the Internet Corporation for Assigned Names and Numbers (ICANN).

The primary function of an RIR is to distribute blocks of IPv4 and IPv6 addresses and Autonomous System Numbers (ASNs) to Local Internet Registries (LIRs), Internet service providers (ISPs), and other network operators within its region. An organization requesting resources must demonstrate a justified need, often through a plan for utilization. The RIR maintains a public, searchable database (the WHOIS or RDAP service) that records which entity holds each IP block or ASN, along with contact and registration details. This registry is critical for routing decisions, network troubleshooting, and law enforcement inquiries.

RIRs sit between the Internet Assigned Numbers Authority (IANA), which allocates large address blocks to each RIR from the global pool, and the LIRs or end users that receive smaller allocations. The five RIRs collectively form the Number Resource Organization (NRO), which coordinates their activities and represents their interests in global Internet governance. Since the exhaustion of the central IPv4 pool in 2011, RIRs have managed dwindling IPv4 inventories through transfer policies and have focused increasingly on IPv6 deployment.