What Is ARIN?
Understanding ARIN (American Registry for Internet Numbers)
Table of Contents
What Is ARIN?
ARIN (American Registry for Internet Numbers) is a Regional Internet Registry (RIR) responsible for managing IP address allocation and ASN (Autonomous System Number) assignment in North America, including United States, Canada, and parts of the Caribbean.
ARIN maintains IP address database, allocates IPv4 and IPv6 addresses to ISPs and organizations, assigns ASNs for network routing, and provides WHOIS database for IP address and ASN information.
ARIN is one of five RIRs worldwide, each managing IP addresses in specific geographic regions. Learn more about ASNs and IP addresses.
ARIN Purpose
1. IP Address Management
ARIN manages IP address allocation in North America, ensuring efficient and fair distribution of IPv4 and IPv6 addresses.
2. ASN Assignment
ARIN assigns ASNs (Autonomous System Numbers) to organizations for network routing and BGP (Border Gateway Protocol) configuration.
3. Database Maintenance
ARIN maintains WHOIS database containing IP address ownership, allocation, and network information.
4. Policy Development
ARIN develops policies for IP address allocation and management, ensuring fair and efficient resource distribution.
5. Resource Registration
ARIN registers IP address allocations and ASN assignments, maintaining accurate records of internet resource ownership.
IP Address Allocation
Allocation Process
ARIN allocates IP addresses to ISPs and organizations based on demonstrated need, following allocation policies and procedures.
IPv4 Allocation
ARIN allocates IPv4 address blocks to organizations, though IPv4 address space is nearly exhausted, requiring careful allocation.
IPv6 Allocation
ARIN allocates IPv6 address blocks to organizations, promoting IPv6 adoption and addressing IPv4 exhaustion.
Allocation Requirements
Organizations must demonstrate need for IP addresses, provide technical justification, and follow ARIN allocation policies.
Transfer and Reallocation
ARIN manages IP address transfers and reallocations, ensuring proper resource management and preventing address hoarding.
ARIN Database
WHOIS Database
ARIN maintains WHOIS database containing IP address and ASN information, including ownership, allocation, and contact details.
Database Access
ARIN database is publicly accessible through WHOIS queries, web interface, and RESTful API, enabling IP address and ASN lookups.
Database Information
ARIN database provides: IP address ownership, allocation dates, organization information, contact details, and network information.
Database Updates
Organizations must keep ARIN database updated with accurate information, ensuring proper resource registration and contactability.
Privacy
ARIN database includes privacy options for contact information, balancing transparency with privacy concerns.
Regional Internet Registries
Five RIRs
There are five Regional Internet Registries (RIRs) worldwide, each managing IP addresses in specific geographic regions:
- ARIN: North America (United States, Canada, Caribbean)
- RIPE NCC: Europe, Middle East, Central Asia
- APNIC: Asia-Pacific region
- LACNIC: Latin America and Caribbean
- AFRINIC: Africa
RIR Coordination
RIRs coordinate through Number Resource Organization (NRO) to ensure consistent policies and efficient resource management globally.
Regional Management
Regional management enables policies tailored to regional needs while maintaining global coordination and consistency.
