Regional Internet Registry (RIR)
A Regional Internet Registry (RIR) is one of five nonprofit organizations -- AfriNIC, APNIC, ARIN, LACNIC, and RIPE NCC -- that IANA has delegated to allocate IP address blocks and autonomous system numbers within a defined geographic region, under a structure documented in RFC 7020. IANA itself holds the top-level pool and distributes large blocks to each RIR under global policy; each RIR then allocates smaller blocks to Local Internet Registries -- typically ISPs and large organizations -- which in turn assign addresses to their own customers, a hierarchy that keeps every address globally unique while pushing day-to-day allocation decisions down to whichever registry actually knows the region and its operators. The RIR that allocated a given block is also the authoritative source for its registration data, which is what a WHOIS or RDAP query against an IP address or ASN actually returns, and what an RPKI ROA for that block is published through. Because each RIR runs its own policy process and database independently, allocation and registration details can differ slightly in format between regions even though the underlying hierarchy is the same everywhere.
By AdminKit team, Netbase JSC · Updated