RDAP FAQ

Q. What is RDAP? A. RDAP stands for Registration Data Access Protocol. It is a specification from the Internet Engineering Task Force (IETF) designed as a replacement for Whois data services for Domain Name Registries (DNRs) and Regional Internet Registries (RIRs). RDAP is specified in RFCs 7480, 7481, 7482, 7483, 7484, and 7485.

Q. How does RDAP differ from Whois? A. RDAP is an HTTP-based REST-style protocol. RDAP responses are specified in JSON. Whois is a text based protocol, utilizing a specialized protocol and port. Whois defines no queries or responses, and as a result the interaction with DNRs and RIRs can vary significantly.

Q. Is RDAP a RESTful Protocol? A. Purists can fight over the meaning of a RESTful protocol, but RDAP meets the industry-accepted definition for a web-based RESTful protocol. It serves JSON over HTTP / HTTPS using URLs to distinguish various resources. The only HTTP methods used by RDAP are HEAD and GET.

Q. Are there RDAP clients available? Yes. ARIN has written a command-line RDAP client called NicInfo (https://github.com/arinlabs/nicinfo). In addition, there are clients available from DNSBelgium (https://github.com/DNSBelgium/rdap/tree/master/client) and CNNIC (https://github.com/cnnic/rdap/tree/master/rdap-client/src/main/java/org/restfulwhois/rdap/client) and CentralNIC (https://github.com/gitpan/rdapper).