Coming Improvements to ARIN's Whois Directory Service

Posted: Friday, 04 June 2010

ARIN is pleased to announce that it plans to deploy an improved Whois service called Whois-RWS on 26 June 2010. Included in the deployment are the following services that provide the general public with access to ARIN's registration data.

  • a RESTful Web Service (RWS)
  • a NICNAME/WHOIS port 43 service
  • a user-friendly web site (

A demo of this service has been available since October 2009. The demonstration service will be available at until the production service is deployed on 26 June 2010.

When using Whois-RWS you will notice some differences in behavior for certain queries and corresponding result sets on the NICNAME/WHOIS port 43 service. ARIN will make a separate announcement on 11 June when it publishes detailed documentation on these differences along with the demonstration service update.

ARIN continues to welcome community participation on the Whois-RWS mailing list, and we invite you to subscribe and share your thoughts and suggestions at:

More detailed information on these changes and other future features that may impact the community at ARIN is available at:


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