An Internet Registry (IR) is an organization responsible for allocating and managing Internet number resources, which include IP addresses and Autonomous System (AS) numbers. These resources are essential for the operation of the Internet, as they ensure that each device or network has a unique identifier for communication purposes.
There are different types of Internet Registries, including Regional Internet Registries (RIRs) and Local Internet Registries (LIRs). RIRs are responsible for managing the allocation and registration of Internet number resources within specific regions of the world. There are five RIRs:
- African Network Information Centre (AFRINIC) serves Africa.
- American Registry for Internet Numbers (ARIN) serves Antarctica, Canada, parts of the Caribbean, and the United States.
- Asia Pacific Network Information Centre (APNIC) serves East Asia, Oceania, South Asia, and Southeast Asia.
- Latin America and Caribbean Network Information Centre (LACNIC) serves most of the Caribbean and all of Latin America.
- Réseaux IP Européens Network Coordination Centre (RIPE NCC) serves Europe, Central Asia, Russia, and West Asia.
LIRs are typically organizations that have been allocated a block of IP addresses by an RIR and assign parts of this block to their customers, which can include Internet service providers, enterprises, or academic institutions.
The RIRs operate under the authority of the Internet Assigned Numbers Authority (IANA), which delegates Internet resources to the RIRs. The RIRs then follow their regional policies to delegate resources to their customers. The RIRs are member-based associations and operate as not-for-profit entities, with policies developed by their respective regional community using inclusive and bottom-up Policy Development Processes (PDP).
The Number Resource Organization (NRO) is an unincorporated coordinating body that liaises informally among the RIRs to act on matters of global importance and to coordinate joint activities.
The Internet Registry system is hierarchical, with the IANA at the top, followed by the RIRs, and then the LIRs, which distribute resources to their members. This system ensures the unique assignment of Internet number resources and prevents conflicts between users and organizations.