Consultation on the Future of ARIN’s Directory Services

Posted: Friday, 14 August 2026
ACSP/Surveys

ARIN is seeking feedback from the community on a proposed road map to streamline and consolidate its directory services.

ARIN currently maintains four directory information protocols: Whois-RWS, RWhois, Whois (Port 43), and RDAP. Supporting multiple redundant services that provide the same information creates additional administrative and operational overhead to the organization. To reduce ARIN's attack surface, streamline operations and lower future operational overhead, ARIN proposes retiring use of older protocols in favor of RDAP as our single, standardized directory service.

This transition is an important step toward improving alignment with established IETF standards.

We have already seen this transition in the domain industry with ICANN mandating the use of RDAP for directory services and dropping the requirement to support Whois. We also expect RDAP clients to become increasingly common in OS distributions in the coming years.

Benefits of Transition to RDAP 

• Enhanced Directory Services: Future enhancements, such as geolocation, will only be implemented in RDAP. 
• Standardization and Automation: RDAP's standardized data structure will improve automation for clients and provide greater flexibility in managing future data changes. 
• Reduced Technical Overhead: Removing old and redundant services will provide time and cost savings for ARIN. 

Timeline and Retirement Planning

This consultation seeks community input for the proposed retirement timelines below. We are keenly interested in receiving specific input on any barriers and/or obstacles these changes may create for customers, as well as steps ARIN can take to ensure a smooth transition. Note that the retirement plans for each impacted directory service will be completed independently, though in some cases work may be conducted concurrently.

Whois-RWS Retirement Plan and Timeline

ARIN currently offers Whois-RWS in two formats: an API and a web interface (located at https://whois.arin.net/ui/). Because the API has the same functionality between Whois-RWS and RDAP, ARIN proposes sunsetting the Whois-RWS API following a 180-day customer outreach program. This will include updating the Whois-RWS payloads to include a notification to users, as well as a robust communication strategy that includes announcements, social promotion, and other outreach.

The Whois-RWS web interface will remain available until work is completed to ensure parity, providing equivalent query capabilities to RDAP. The changeover from Whois-RWS to RDAP will be transparent to end users visiting that URL. ARIN will inform the community a minimum of 30 days before the retirement of the Whois-RWS web interface, noting the switch to RDAP will not change the end user experience.

RWhois Retirement Plan and Timeline

When RWhois server use is retired, we will provide organizations with a recommendation for an open-source RDAP server implementation. To help ease the transition and migration of data, ARIN plans to provide a conversion tool for populating that recommended RDAP server with existing RWhois data. When the tool is publicly available, ARIN proposes a 365-day sunsetting timeline for RWhois. This will allow for robust communication and direct outreach to organizations who use RWhois and plan to either convert to the RDAP client or discontinue their use of local clients and report their reassignment information directly to ARIN instead.

Whois (Port 43) Retirement Plan and Timeline

ARIN understands that Whois (Port 43) carries a high volume of queries and will require the longest timeline to retire. We propose a two-year sunsetting window, during which ARIN will engage in active outreach to users. This will include updates to Whois (Port 43) results during the sunsetting period that will contain information about the retirement deadline.

Because Whois (Port 43) has been the historically preferred method of querying Internet number resource registration data, it remains heavily used by cybersecurity professionals, researchers, law enforcement, and many other types of organizations. ARIN will seek to engage beyond our community to raise awareness of the planned retirement date for Whois (Port 43).

After the retirement of the directory service protocols described above and listed below, ARIN will only support RDAP as our single, standardized directory service.

• Whois-RWS: on or after 1 July 2027
• RWhois: dependent on migration tool release date, but no sooner than 1 January 2028
• Whois (Port 43): on or after 1 January 2029

Throughout the sunsetting process for all services, ARIN will engage with our community to ensure customers and users are well-informed about the retirement of the described services and ARIN's transition to RDAP as its standard directory service.

We look forward to your feedback on the proposed timelines for retirement for Whois-RWS, RWhois, and Whois (Port 43). We ask that you consider each service independently, with the understanding that each of these services may impact your organization differently.

Please provide comments to [email protected]. You can subscribe to this mailing list at https://lists.arin.net/mailman/listinfo/arin-consult.

This consultation will remain open until 5:00 PM ET on 14 September 2026. ARIN seeks clear direction through community input, so your feedback is important.

Thank you for your continued support in improving ARIN's services.

Regards,

John Curran
President and CEO
ARIN

Relevant links:

• Presentation from ARIN 56: https://www.arin.net/participate/meetings/ARIN56/materials/arin56_directoryservices.pdf
• IETF Standard for RDAP: https://www.rfc-editor.org/info/std95
• Guide to RDAP Client Implementations: https://rdap.rcode3.com/client_implementations/index.html
• ARIN RDAP Documentation: https://www.arin.net/resources/registry/whois/rdap/