ARIN vs. RIPE vs. APNIC: How Regional Registries Assign ASNs

Autonomous System Numbers (ASNs) are unique identifiers that allow separately administered routing domains to exchange dynamic routing information via the Border Gateway Protocol (BGP) across the global internet. Regional Internet Registries (RIRs)—namely ARIN, RIPE NCC, APNIC, LACNIC, and AFRINIC—manage these critical numbering resources within their respective geographic footprints under the overarching policy coordination of the Internet Assigned Numbers Authority (IANA). Whether you are setting up multi-homed BGP or preparing for an enterprise network expansion, acquiring and managing an ASN requires navigating the specific operational policies, documentation prerequisites, and fee structures of your designated regional registry.

To quickly verify and inspect details about any active autonomous system, you can use the ASN Lookup tool on XiaTools to instantly check registry ownership, assigned prefixes, and organization details.

Global Governance: IANA and the Five RIRs

The distribution of internet number resources follows a hierarchical model. The Internet Corporation for Assigned Names and Numbers (ICANN), through IANA, maintains the global pool of unallocated 16-bit and 32-bit ASNs, distributing large blocks to the five RIRs based on projected regional demand. Once an RIR receives its block, it evaluates local applications, assigns numbers to network operators, and maintains the authoritative public registration databases (Whois/RDAP).

The division of labor among the five RIRs ensures localized governance tailored to regional telecommunications infrastructure, legal environments, and economic factors. While the technical mechanics of BGP remain identical worldwide, the administrative friction points, verification criteria, and recurring membership dues differ significantly depending on where your organization is legally incorporated and where your network infrastructure resides.

+---------------------------------------------------+
|                       IANA                        | 
+---------------------------------------------------+
                          |
        +-----------------+-----------------+
        |                 |                 |  
     [ARIN]            [RIPE]            [APNIC] ... (LACNIC, AFRINIC)
        |                 |                 |
    (Americas)        (Europe/ME)     (Asia-Pacific)

Comparing the Major Registries: ARIN, RIPE, and APNIC

Understanding how the three largest RIRs operate helps prevent costly administrative delays during network deployments.

ARIN (American Registry for Internet Numbers)

ARIN serves Canada, the United States, and several Caribbean and North Atlantic islands. ARIN operates under a strict legal contract framework and places heavy emphasis on organizational verification, requiring detailed proof of legal business incorporation and documented justification for why a 16-bit or 32-bit ASN is required.

• Service Region: North America and parts of the Caribbean.
• Fee Model: Annual service maintenance fees tiered by organization size or resource holdings.
• Policy Enforcement: Strict multi-homing or unique routing policy requirements.

RIPE NCC (Réseaux IP Européens Network Coordination Centre)

Serving Europe, the Middle East, and parts of Central Asia, RIPE NCC operates via a local registry model where LIRs (Local Internet Registries) act as intermediaries between the end-user and the central database. RIPE historically maintains a more streamlined process for pure resource requests, though membership agreements and annual administrative contributions are mandatory.

• Service Region: Europe, Middle East, Central Asia.
• Fee Model: Annual flat-rate billing per LIR account regardless of the number of resources held.
• Policy Enforcement: Managed heavily through community-driven policy proposals and LIR sponsorship.

APNIC (Asia-Pacific Network Information Centre)

APNIC covers the vast and diverse Asia-Pacific region, spanning from Pakistan to New Zealand and up through East Asia. APNIC offers flexible membership tiers, localized support in multiple languages, and direct interaction for organizations operating across disparate national regulatory frameworks within the region.

• Service Region: Asia-Pacific.
• Fee Model: Tiered membership fees based on the size of IPv4/IPv6 address holdings and ASN allocations.
• Policy Enforcement: Regional policy flexibility accommodating developing telecommunications markets.

Technical Requirements for ASN Assignment

Historically, ASNs were 16-bit integers ranging from 1 to 64495 (with specific blocks reserved for private use). Due to IPv4 exhaustion and rapid enterprise growth, 32-bit ASNs (ranging up to 4294967295) were introduced. Today, all major RIRs assign 32-bit ASNs by default unless an explicit operational constraint requires a 16-bit assignment.

To qualify for an ASN from ARIN, RIPE, or APNIC, an organization generally must satisfy one of two primary technical criteria:

1. Multi-homing: The applicant intends to connect to two or more distinct upstream Internet Service Providers (ISPs) simultaneously and exchange routing information using BGP.
2. Unique Routing Policy: The applicant demonstrates a single-homed network architecture with a distinct routing policy that cannot be adequately accommodated by the upstream provider's static routing or aggregation.

Step-by-Step Guide to Requesting an ASN

Navigating the application process requires careful preparation. Follow these steps to secure your ASN:

1. Establish an Account: Navigate to your regional registry's portal (e.g., ARIN Online, RIPE Access, or MyAPNIC) and create an organizational administrative account.
2. Verify Legal Identity: Submit official corporate registration documents establishing your legal entity name and operational jurisdiction within the RIR's service region.
3. Prepare Justification: Document your network design. List your upstream providers, provide your assigned public IP address blocks (such as 192.0.2.0/24 or IPv6 prefix 2001:db8::/32), and state your BGP peering intentions.
4. Submit the Request: Fill out the specific ASN request template within the registry portal, selecting either a 16-bit or 32-bit assignment.
5. Sign the Registration Services Agreement (RSA): Pay the required initial setup and annual maintenance fees, and execute the legal contract governing resource usage.
6. Configure Upstreams: Once the registry approves your request and issues the ASN, provide the number to your upstream ISPs so they can authorize your BGP announcements.

Verifying and Troubleshooting ASN Allocations

After your registry assigns an ASN, network engineers must verify that global routing tables and registry databases reflect the correct ownership and origin. You can query authoritative registry databases and routing tables using standard command-line tools.

To query Whois/RDAP records directly from your terminal, use the whois utility:

whois AS64496

To check active BGP path information and origin verification across public looking glasses or local routing daemons, test connectivity or query routing status:

nslookup -type=txt AS64496.origin.asn.cymru.com

When troubleshooting routing leakage or incorrect registry attributes, ensure your Routing Registry (IRR) objects (such as aut-num and route/route6 objects) match your actual BGP advertisements. Upstream providers frequently utilize automated Internet Routing Registries to generate prefix filters, dropping announcements that lack valid registry backing.

Common Mistakes and How to Fix Them

• Requesting an ASN for Internal-Only Use: Organizations often mistakenly apply to an RIR for an ASN to run internal iBGP across private datacenters. Fix this by using Private Autonomous System Numbers (ranging from 64512 to 65534 for 16-bit, and 4200000000 to 4294967295 for 32-bit) which require no registry involvement.
• Failing to Maintain Up-to-Date POCs: Forgetting to update Point of Contact (POC) email addresses leads to missed annual invoice notices and subsequent resource revocation by the registry. Always maintain current technical and billing contacts in your RIR portal.
• Neglecting IRR and RPKI Maintenance: Obtaining an ASN is only half the battle. Failing to create Route Origin Authorizations (ROAs) in your RIR portal leaves your announced prefixes vulnerable to hijacking and filtering by modern route validation systems.

ASN Assignment Checklist

• Determine your correct geographic RIR (ARIN, RIPE, APNIC, LACNIC, or AFRINIC)
• Confirm your network meets multi-homing or unique routing policy criteria
• Gather corporate legal registration and tax verification documents
• Set up an authenticated account on the RIR portal
• Submit the ASN request template with explicit technical justification
• Execute the Registry Services Agreement and pay applicable fees
• Publish corresponding IRR objects and RPKI ROAs for your announced IP prefixes