Removal of TLS 1.0 Support for Whois-RWS and RDAP

Posted: Wednesday, 12 February 2020

On 15 October 2019 and 13 January 2020, we announced plans to implement a change with ARIN’s Whois-RWS and RDAP services. We noted that this change may impact the way you interface programmatically with ARIN to query and retrieve information from these services.

With this change, ARIN no longer supports TLS version 1.0 for Whois-RWS and RDAP services because of well-known security issues with this version of the protocol. We will continue to support TLS 1.1 and 1.2. Please make sure your client implementation will support TLS 1.1 or 1.2. Read for further details.

ARIN implemented these changes to remove TLS 1.0 support on 12 February 2020. We recommend that you review your clients that interface with the Whois-RWS and RDAP services, and verify that your clients are operating successfully with ARIN.

If you are still using TLS 1.0, you will need to make configuration changes to use TLS 1.1 or TLS 1.2 to successfully interface with ARIN. If you have additional questions, comments, or issues, please submit an Ask ARIN ticket using your ARIN Online account, or contact the Registration Services Help Desk by phone Monday through Friday, 7:00 AM to 7:00 PM ET at +1.703.227.0660.


Mark Kosters
Chief Technology Officer
American Registry for Internet Numbers (ARIN)