Regional Internet Registries (ARIN, RIPE, APNIC)
Explore the five RIRs that manage IP address distribution globally, their service regions, policies, and WHOIS databases.
What Are Regional Internet Registries?
Regional Internet Registries (RIRs) are nonprofit organizations that manage the allocation and registration of IP addresses and AS numbers within their geographic regions. They receive large address blocks from IANA and distribute them to ISPs, hosting companies, and other organizations.
Each RIR operates independently with its own membership, board, and policy development process, but they coordinate through the Number Resource Organization (NRO).
The Five RIRs
ARIN (American Registry for Internet Numbers)
- Region: United States, Canada, and parts of the Caribbean
- Founded: 1997
- Headquarters: Chantilly, Virginia, USA
- WHOIS: whois.arin.net
- Status: Free IPv4 pool exhausted (September 2015). Operates a waiting list for returned space.
RIPE NCC (Reseaux IP Europeens Network Coordination Centre)
- Region: Europe, Middle East, Central Asia
- Founded: 1992
- Headquarters: Amsterdam, Netherlands
- WHOIS: whois.ripe.net
- Status: Last IPv4 /8 reached in 2012. Only allocates /24 blocks to new members.
APNIC (Asia-Pacific Network Information Centre)
- Region: Asia-Pacific (East Asia, South Asia, Oceania)
- Founded: 1993
- Headquarters: Brisbane, Australia
- WHOIS: whois.apnic.net
- Status: Reached final /8 in April 2011. Strict rationing policies.
LACNIC (Latin American and Caribbean Internet Addresses Registry)
- Region: Latin America and Caribbean
- Founded: 2002
- Headquarters: Montevideo, Uruguay
- WHOIS: whois.lacnic.net
- Status: Reached final /10 in June 2014.
AFRINIC (African Network Information Centre)
- Region: Africa
- Founded: 2005
- Headquarters: Ebene, Mauritius
- WHOIS: whois.afrinic.net
- Status: Has faced governance challenges; limited IPv4 space remains.
Using RIR WHOIS Databases
Each RIR maintains a public WHOIS database that lets you look up who owns an IP address block:
# Query ARIN
whois -h whois.arin.net 8.8.8.8
# Query RIPE
whois -h whois.ripe.net 185.12.64.0
# Query APNIC
whois -h whois.apnic.net 1.1.1.1
# Auto-detect the right RIR
whois 8.8.8.8
WHOIS results include the organization name, address block boundaries, abuse contact, and registration dates.
Policy Development
Each RIR develops policies through an open, community-driven process:
- A member or community participant proposes a policy change.
- Discussion occurs on public mailing lists and at regional meetings.
- Consensus is determined by the community.
- The RIR board ratifies or rejects the proposal.
IP Address Transfers Between RIRs
Organizations can transfer IP address blocks between RIRs, subject to each registry's transfer policies. This is increasingly common as IPv4 scarcity drives the secondary market. The sending and receiving RIRs must both approve the transfer, and WHOIS records are updated accordingly.