The Registration Data Access Protocol (RDAP) is a computer network communications protocol standardized by a working group at the Internet Engineering Task Force in 2015, after experimental developments and thorough discussions. It is a successor to the WHOIS protocol, used to look up relevant registration data from such Internet resources as domain names, IP addresses, and autonomous system numbers. While WHOIS essentially retrieves free text, RDAP delivers data in a standard, machine-readable

JSON JSON (JavaScript Object Notation, pronounced ; also ) is an open standard file format and data interchange format that uses human-readable text to store and transmit data objects consisting of attribute–value pairs and arrays (or other ser ...

format. In order to accomplish this goal, the output of all operative WHOIS servers was analyzed, taking a census of the labels they used. RDAP designers, many of whom are members of number or

name A name is a term used for identification by an external observer. They can identify a class or category of things, or a single thing, either uniquely, or within a given context. The entity identified by a name is called its referent. A personal ...

registries, strove to keep the protocol as simple as possible, since complexity was considered one of the reasons why previous attempts, such as

CRISP CRISP may refer to: * Center for Research in Security and Privacy, largest research center for IT security in Europe * C-language Reduced Instruction Set Processor, an AT&T microprocessor design * Chesapeake Regional Information System for our Pat ...

, failed. RDAP is based on RESTful web services, so that error codes, user identification, authentication, and access control can be delivered through HTTP. The biggest delay in getting RDAP done turned out to be the ''bootstrap'', figuring out where the server is for each top level domain, IP range, or ASN range.

IANA The Internet Assigned Numbers Authority (IANA) is a standards organization that oversees global IP address allocation, autonomous system number allocation, root zone management in the Domain Name System (DNS), media types, and other Interne ...

agreed to host the bootstrap information in suitable registries, and publish it at a well-known location URLs in JSON format. Those registries started empty and will be gradually populated as registrants of domains and address spaces provide RDAP server information to IANA. For number registries,

ARIN The American Registry for Internet Numbers (ARIN) is the regional Internet registry for Canada, the United States, and many Caribbean and North Atlantic islands. ARIN manages the distribution of Internet number resources, including IPv4 and IPv ...

set up a public RDAP service which also features a bootstrap URL, similar to what they do for WHOIS. For name registries,

ICANN The Internet Corporation for Assigned Names and Numbers (ICANN ) is an American multistakeholder group and nonprofit organization responsible for coordinating the maintenance and procedures of several databases related to the namespaces ...

requires RDAP compliance since 2013.

Examples

An example of a RDAP client and server exchange: Client: GET /rdap/ip/203.0.113.0/24 HTTP/1.1 Host: rdap.example.com Accept: application/rdap+json rdap.example.com: HTTP/1.1 301 Moved Permanently Location: http://rdap-ip.example.com/rdap/ip/203.0.113.0/24 Content-Length: 0 Content-Type: application/rdap+json Client: GET /rdap/ip/203.0.113.0/24 HTTP/1.1 Host: rdap-ip.example.com Accept: application/rdap+json rdap-ip.example.com: HTTP/1.1 200 OK Content-Type: application/rdap+json Content-Length: 9001

Number resources

RDAP databases for assigned IP numbers are maintained by five Regional Internet registries.

maintains a bootstrap database. Thanks to the standard document format, tasks such as, for example, getting the abuse team address of a given IP number can be accomplished in a fully automated manner.

Name resources

RDAP databases for registered names are maintained after ICANN agreement. Name resources are much slower, as the number of registries under ICANN is huge. In addition, as the GDPR became enforceable, in May 2018, the problem of personal data divulged via WHOIS or RDAP slowed adoption further.

References

External links

IANA registry for RDAP services
* - A command line Registry Data Access Protocol (RDAP) client
rdap.org
- An end point for RDAP queries
RDAP JSON Values at IANA

RDAP page at APNIC

RDAP page at LACNIC
* * Internet protocols Internet Standards {{internet-stub