IP & ASN Registry Services

Manage Resource Records

ARIN offers many methods and tools for customers to manage and secure their resource records. Get instructions and links to information you need to administer your resource records, including details about API Keys, managing reverse DNS, and options for reporting reassignments and modifying networks.

Transferring IPs & ASNs

Get information and instructions on options for transferring number resources, including IPv4 and IPv6 address blocks and ASNs.

Reporting Reassignments

Organizations that receive IPv4 or IPv6 address space allocations from ARIN directly or as a downstream customer of another organization must provide reassignment/reallocation information via either Referral Whois (RWhois), the Shared Whois Project (SWIP), or a distributed service in compliance with ARIN policy.

Autonomous System Originations (Origin AS)

The Origin Autonomous System (AS) field is an optional field collected by ARIN during all IPv4 and IPv6 block transactions (allocation and assignment requests, reallocation and reassignment actions, transfer and experimental requests). This additional field is used by IP address block holders (including legacy address holders) to record a list of the Autonomous System Numbers (ASNs), separated by commas or whitespace, from which the addresses in the address block(s) may originate.

Collecting and making Origin AS information available to the community is part of the implementation of Policy ARIN-2006-3: Capturing Originations in Templates, included in the ARIN Number Resource Policy Manual (NRPM) Section 3.5: Autonomous System Originations. This information is available using our Bulk Whois service.


Whois is a query and response protocol that is used for querying databases that store registered users or assignees of an Internet resource, such as IP addresses or domain names. ARIN’s Whois service is a public resource that allows a user to retrieve information about IP number resources, organizations, and Points of Contact (POCs) registered with ARIN.

Note: ARIN will not collect any personal information for inclusion in its public Whois. The only information that is published in ARIN’s public Whois is organizational information associated with an Internet number resource, including POC records. The personal information you provide when creating your ARIN Online Profile is kept strictly confidential and is not displayed in your public Whois record.

ARIN provides access to Whois data through the following methods:

Whois Registration Data Access Protocol (Whois/RDAP)

RDAP was developed by the IETF to enable querying registration data and to eventually replace the WHOIS protocol. ARIN provides Whois/RDAP through a web search interface. RDAP can also be accessed using clients or scripts that use query URLs.

Whois Registration Representational State Transfer (REST)ful Web Service (Whois-RWS)

Whois-RWS is an ARIN-specific protocol and is still supported, but we recommend users move to Whois/RDAP. The Whois-RWS web interface and API are still supported, as is querying using a CLI.

Registration Services Help Desk
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