Whois/Registration Data Access Protocol (RDAP)

Looking for instructions on using ARIN’s Whois/RDAP search? Visit ARIN’s Whois page.

Whois/RDAP search

Overview

Registry Data Access Protocol (RDAP) is a Whois alternative for querying resource registration data from Domain Name Registries (DNRs) and Regional Internet Registries (RIRs) like ARIN. When you use RDAP clients to query registration data, responses are delivered in JavaScript Object Notation (JSON) format (instead of the text format provided by Whois). When you use the Search Site or Whois feature or use https://search.arin.net/rdap/ for Whois queries, RDAP responses are returned in formatted HTML.

Note: Some types of information (such as domain information) are not provided by ARIN’s Whois service, but may be available from other Whois services.

How does RDAP differ from Whois?

  • RDAP is an HTTP-based REST-style protocol with standardized responses specified in JSON, whereas Whois is a text based protocol, utilizing a specialized protocol and port. RDAP meets the industry-accepted definition for a web-based RESTful protocol. It serves JSON responses over HTTP/HTTPS using URLs to distinguish various resources. The only HTTP methods used by RDAP are HEAD and GET.
  • RDAP response data objects are easily translated into languages other than English, whereas Whois response data objects may not be.
  • RDAP responses offer direct referrals to other RIRs, whereas Whois defines no queries or responses, and interaction with DNRs and RIRs can vary significantly.

Understanding Bootstrapping

A bootstrap server is a special type of server for helping clients find an authoritative server to query (this is called bootstrapping). Query bootstrapping can be an expensive process for some clients, and a bootstrap server can alleviate that expense by pre-loading the bootstrapping information. To utilize an RDAP bootstrap server, an RDAP client simply sends RDAP queries and receives HTTP redirects to the authoritative server.

Bootstrap files are JSON files specified in RFC 7484. The Internet Assigned Numbers Authority (IANA) publishes the following files:

  • Autonomous System Numbers
  • IPv4 Allocations
  • IPv6 Allocations
  • Domain Registries

If you use the correct query URL in your RDAP query, ARIN’s bootstrap server automatically sends the queries to the correct server.

Operating Your Own Bootstrap Server

The ARIN bootstrap server is open source and can be found on GitHub.

How to Get Registration Information Using RDAP

RDAP is a command-line tool. You can use RDAP to get registration information from ARIN using the following methods:

Using the Whois/RDAP Web Interface

You can access the Whois/RDAP web interface by choosing one of these options:

  • Enter https://search.arin.net/rdap/ into the address bar of your web browser. After reaching the ARIN Whois/RDAP page, enter your search term in the field and choose Search.
  • Enter the item you want to search Whois for into the search box (labeled Search Site or Whois). ARIN sends this query to search.arin.net, and returns results based on what type of search it guesses you were trying to perform. For example, if the search engine thinks you are searching for information about subject areas on the web site (for example, policy, services, or ARIN functions), it returns results from www.arin.net (you can then choose the Search ARIN’s Whois instead link on the results page). If you enter a search term that has a specific format, such as an IP address (for example, 2001:500:11::) or an Autonomous System Number (ASN) (for example, AS64496), the search engine automatically queries Whois/RDAP.

For more information on using the Whois/RDAP web interface, visit the Whois page.

Using an RDAP Client

ARIN has written a command-line RDAP client called NicInfo.

In addition, there are clients available from DNSBelgium, CNNIC, and CentralNIC.

RDAP queries are entered with a specific structure. The following examples use the NicInfo client.

NicInfo Query Structure

The parts of an RDAP query are comprised of the object you are querying and the bootstrap server (optional). For example, to query an object using ARIN’s bootstrap server, you would enter the command:

nicinfo <object> --base http://rdap.arin.net/bootstrap/

where <object> is an IP address, domain name, ASN, or entity identifier.

To query an object without using ARIN’s bootstrap server, you would enter:

nicinfo <object> --base http://rdap.arin.net/registry/

where <object> is an IP address, domain name, ASN, or entity identifier.

For a specific example, to query an ASN of AS64496, you would enter the following query (using bootstrap):

nicinfo asn --base http://rdap.arin.net/bootstrap

The returned response for a query for AS64496 might look like the following example.

Sample Output
computer:~ user$ nicinfo AS64496 --base http://rdap.arin.net/bootstrap/
# NicInfo v.1.4.1

# Result type is ASNUMBER.

[ RESPONSE DATA ]
  1= AS64496
     `--- 1= Internet Assigned Numbers Authority ( IANA )
    |--- 1= Internet Corporation for Assigned Names and Number ( IANA-ARIN )
      `--- 2= ICANN ( IANA-IP-ARIN )

  [ AS NUMBER ]
     Handle:  AS64496
      Start AS Number:  64496
      End AS Number:  64511
      Last Changed:  Wed, 14 Jan 2009 18:10:12 -0500
      Registration:  Wed, 03 Dec 2008 00:00:00 -0500
      Remarks:  -- Registration Comments --
        1:  Reserved for use in documentation and sample code [RFC5398]

  [ ENTITY ]
     Handle:  IANA
      Common Name:  Internet Assigned Numbers Authority
      Roles:  Registrant
      Last Changed:  Fri, 31 Aug 2012 13:32:25 -0400

Using Query URLs

You can create RDAP queries with a URL structure that can be used with command-line tools like cURL, or included in scripts written in languages like Ruby or perl.

Query URLs have the following structure:

<rdap-url><object>/<search-item>

where <rdap-url> is the registration information provider’s RDAP server URL (in this case, ARIN’s RDAP URL) and <object> is an IP address, domain name, ASN, or entity identifier. The following sections provide examples of RDAP queries.

IP Networks

Queries for information about IP networks are of the form:

<rdap-url>/ip/<search-term> or /ip/<address>/<prefix>

where the path segment following ip is either an IPv4 dotted decimal or IPv6 [RFC5952] address (i.e., 2001:500:11::) or an IPv4 or IPv6 Classless Inter-domain Routing (CIDR) [RFC4632] notation address block (i.e., 12.0.0.0/8).

Query Examples

https://rdap.arin.net/bootstrap/ip/2001:500:11:: https://rdap.arin.net/bootstrap/ip/12.0.0.0/8

Sample Output

# NicInfo v.1.4.1

# Result type is IP.

[ RESPONSE DATA ]  
  1= NET6-2001-500-11-1
     |--- 1= ICANN ( ICANN )
     |    |--- 1= Internet Corporation for Assigned Names and Number ( ICANN-NET )
     |    |--- 2= Terry Manderson ( MANDE13-ARIN )
     |    |--- 3= David Closson ( DCL131-ARIN )
     |    |--- 4= David Soltero ( DSO63-ARIN )
     |    `--- 5= Josh Jenkins ( JENKI373-ARIN )
     `--- 2= ICANN ( IANA-IP-ARIN )

           [ IP NETWORK ]
                   Handle:  NET6-2001-500-11-1
            Start Address:  2001:500:11::
              End Address:  2001:500:11:ffff:ffff:ffff:ffff:ffff
                    CIDRs:  2001:500:11::/48
               IP Version:  v6
                     Type:  DIRECT ASSIGNMENT
                   Status:  Active
             Last Changed:  Fri, 24 Oct 2014 15:51:14 -0400
             Registration:  Wed, 29 Nov 2006 16:01:53 -0500

               [ ENTITY ]
                   Handle:  ICANN
              Common Name:  ICANN
                    Roles:  Registrant
             Last Changed:  Wed, 04 Apr 2018 13:55:13 -0400
             Registration:  Fri, 30 Mar 2001 00:00:00 -0500

               [ ENTITY ]
                   Handle:  ICANN-NET
              Common Name:  Internet Corporation for Assigned Names and Number
             Organization:  Internet Corporation for Assigned Names and Number
                    Email:  ops@icann.org
                    Phone:  +1-310-301-3889 ( work, voice )
                    Roles:  Abuse
                   Status:  Validated
             Last Changed:  Mon, 15 Oct 2018 08:56:20 -0400
             Registration:  Tue, 26 Jun 2001 16:55:06 -0400

               [ ENTITY ]
                   Handle:  MANDE13-ARIN
              Common Name:  Terry Manderson
                    Email:  terry.manderson@icann.org
                    Phone:  +1-310-301-3850 ( work, voice )
                    Roles:  Technical
                   Status:  Validated
             Last Changed:  Thu, 10 Oct 2013 01:35:07 -0400
             Registration:  Thu, 10 Oct 2013 01:35:07 -0400

               [ ENTITY ]
                   Handle:  DCL131-ARIN
              Common Name:  David Closson
                    Email:  david.closson@icann.org
                    Phone:  +1-310-578-8670 ( work, voice )
                    Phone:  +1-310-823-8649 ( work, fax )
                    Roles:  Technical
                   Status:  Validated
             Last Changed:  Wed, 04 Apr 2018 13:30:38 -0400
             Registration:  Sat, 21 Mar 2009 21:42:03 -0400

               [ ENTITY ]
                   Handle:  DSO63-ARIN
              Common Name:  David Soltero
                    Email:  david.soltero@icann.org
                    Phone:  +1-310-301-3890 ( work, voice )
                    Phone:  +1-310-926-9635 ( work, cell )
                    Phone:  +1-310-823-8649 ( work, fax )
                    Roles:  Technical
                   Status:  Validated
             Last Changed:  Mon, 23 Apr 2018 15:06:17 -0400
             Registration:  Sat, 21 Mar 2009 21:42:03 -0400

               [ ENTITY ]
                   Handle:  JENKI373-ARIN
              Common Name:  Josh Jenkins
                    Email:  josh.jenkins@icann.org
                    Phone:  +1-310-578-8699 ( work, voice )
                    Roles:  Technical, Administrative
                   Status:  Validated
             Last Changed:  Wed, 04 Apr 2018 13:47:23 -0400
             Registration:  Wed, 04 Apr 2018 13:47:23 -0400

               [ ENTITY ]
                   Handle:  IANA-IP-ARIN
              Common Name:  ICANN
             Organization:  ICANN
                    Email:  abuse@iana.org
                    Phone:  +1-310-301-5820 ( work, voice )
                    Roles:  Technical, Abuse
                   Status:  Validated
             Last Changed:  Mon, 11 Aug 2014 12:22:29 -0400
             Registration:  Sun, 24 Aug 2003 23:00:00 -0400
                  Remarks:  -- Registration Comments --
                        1:  Think we're attacking you? Please look here:  
                        2:  http://www.iana.org/abuse

Domains (in-addr.arpa or ip6.arpa)

This query searches for an in-addr.arpa or ip6.arpa domain (sometimes referred to as an inverse address domain) that matches the search term you enter (for example, 154.54.in-addr.arpa). These domains are used in reverse DNS, where an IP address is resolved to a hostname. The in-addr.arpa and ip6.arpa domains are entered into a registration database when reverse DNS is configured for IP addresses held by an organization.

Queries for domain information are of the form:

<rdap-url>/domain/<arpa-addr>

where <rdap-url> is the registration information provider’s RDAP server URL (in this case, ARIN’s RDAP URL) and arpa-addr is an in-addr.arpa or ip6.arpa domain.

Query Example

https://rdap.arin.net/registry/domain/154.54.in-addr.arpa

Sample Output

# NicInfo v.1.4.1

# Result type is DOMAIN.

[ RESPONSE DATA ]  
  1= 154.54.in-addr.arpa. ( 154.54.in-addr.arpa. )
     |--- 1= Amazon Technologies Inc. ( AT-88-Z )
     |    |--- 1= Amazon EC2 Abuse ( AEA8-ARIN )
     |    |--- 2= Amazon AWS Network Operations ( AANO1-ARIN )
     |    |--- 3= Amazon EC2 Network Operations ( ANO24-ARIN )
     |    `--- 4= IP Management ( IPMAN40-ARIN )
     `--- 2= NET-54-144-0-0-1
          `--- 1= Amazon Technologies Inc. ( AT-88-Z )
               |--- 1= Amazon EC2 Abuse ( AEA8-ARIN )
               |--- 2= Amazon AWS Network Operations ( AANO1-ARIN )
               |--- 3= Amazon EC2 Network Operations ( ANO24-ARIN )
               `--- 4= IP Management ( IPMAN40-ARIN )

               [ DOMAIN ]
                   Handle:  154.54.in-addr.arpa.
              Domain Name:  154.54.in-addr.arpa.
             Last Changed:  Wed, 05 Nov 2014 20:25:49 -0500

               [ ENTITY ]
                   Handle:  AT-88-Z
              Common Name:  Amazon Technologies Inc.
                    Roles:  Registrant
             Last Changed:  Sat, 28 Jan 2017 08:32:29 -0500
             Registration:  Thu, 08 Dec 2011 13:34:25 -0500
                  Remarks:  -- Registration Comments --
                        1:  All abuse reports MUST include:
                        2:  * src IP
                        3:  * dest IP (your IP)
                        4:  * dest port
                        5:  * Accurate date/timestamp and timezone of activity
                        6:  * Intensity/frequency (short log extracts)
                        7:  * Your contact details (phone and email) Without these we will be
                         :  unable to identify the correct owner of the IP address at that
                         :  point in time.

               [ ENTITY ]
                   Handle:  AEA8-ARIN
              Common Name:  Amazon EC2 Abuse
             Organization:  Amazon EC2 Abuse
                    Email:  abuse@amazonaws.com
                    Phone:  +1-206-266-4064 ( work, voice )
                    Roles:  Abuse
                   Status:  Validated
             Last Changed:  Fri, 15 Jun 2018 23:29:56 -0400
             Registration:  Mon, 24 Mar 2008 14:12:07 -0400
                  Remarks:  -- Registration Comments --
                        1:  Amazon Web Services Abuse - The activity you have detected
                         :  originates from a dynamic hosting environment. For fastest
                         :  response, please submit abuse reports to abuse@amazonaws.com
                        2:  All reports MUST include:
                        3:  * src IP
                        4:  * dest IP (your IP)
                        5:  * dest port
                        6:  * Accurate date/timestamp and timezone of activity
                        7:  * Intensity/frequency (short log extracts)
                        8:  * Your contact details (phone and email)
                        9:  Without these we will be unable to identify the correct owner of
                         :  the IP address at that point in time.

               [ ENTITY ]
                   Handle:  AANO1-ARIN
              Common Name:  Amazon AWS Network Operations
             Organization:  Amazon AWS Network Operations
                    Email:  amzn-noc-contact@amazon.com
                    Phone:  +1-206-266-4064 ( work, voice )
                    Roles:  Noc
                   Status:  Validated
             Last Changed:  Tue, 03 Apr 2018 15:57:43 -0400
             Registration:  Thu, 04 Mar 2010 18:38:30 -0500

               [ ENTITY ]
                   Handle:  ANO24-ARIN
              Common Name:  Amazon EC2 Network Operations
             Organization:  Amazon EC2 Network Operations
                    Email:  amzn-noc-contact@amazon.com
                    Phone:  +1-206-266-4064 ( work, voice )
                    Roles:  Technical
                   Status:  Validated
             Last Changed:  Wed, 21 Nov 2018 12:23:37 -0500
             Registration:  Mon, 19 Sep 2005 06:00:05 -0400

               [ ENTITY ]
                   Handle:  IPMAN40-ARIN
              Common Name:  IP Management
             Organization:  IP Management
                    Email:  ipmanagement@amazon.com
                    Phone:  +1-206-266-4064 ( work, voice )
                    Roles:  Administrative
                   Status:  Validated
             Last Changed:  Fri, 30 Mar 2018 09:08:28 -0400
             Registration:  Tue, 12 Nov 2013 22:06:06 -0500

           [ IP NETWORK ]
                   Handle:  NET-54-144-0-0-1
            Start Address:  54.144.0.0
              End Address:  54.159.255.255
                    CIDRs:  54.144.0.0/12
               IP Version:  v4
                     Type:  DIRECT ALLOCATION
                   Status:  Active
             Last Changed:  Thu, 13 Nov 2014 14:02:56 -0500
             Registration:  Wed, 22 Oct 2014 23:00:00 -0400

Origin AS

The query to search for networks associated with an Origin AS value is:

<rdap-url>/arin_originas0_networksbyoriginas/<ORIGIN_AS_NUMBER>

where ORIGIN_AS_NUMBER is the value in the Origin AS field associated with the network. The Origin AS field contains a list of the ASNs, separated by commas or whitespace, from which the addresses in the network address block(s) may originate. (Do not include the AS prefix.)

To prevent performance issues, an Origin AS query limits the returned networks to 256.

Query Example

https://rdap.arin.net/registry/arin_originas0_networksbyoriginas/64496

Sample Output

{
  "rdapConformance" : [ "rdap_level_0", "arin_originas0", "cidr0" ],
  "notices" : [ {
    "title" : "Terms of Service",
    "description" : [ "By using the ARIN RDAP/Whois service, you are agreeing to the RDAP/Whois Terms of Use" ],
    "links" : [ {
      "value" : "https://rdap.arin.net/registry/arin_originas0_networksbyoriginas/64496",
      "rel" : "about",
      "type" : "text/html",
      "href" : "https://www.arin.net/whois_tou.html"
    } ]
  }, {
    "title" : "Whois Inaccuracy Reporting",
    "description" : [ "If you see inaccuracies in the results, please visit: " ],
    "links" : [ {
      "value" : "https://rdap.arin.net/registry/arin_originas0_networksbyoriginas/64496",
      "rel" : "about",
      "type" : "text/html",
      "href" : "https://www.arin.net/resources/whois_reporting/index.html"
    } ]
  }, {
    "title" : "Copyright Notice",
    "description" : [ "Copyright 1997-2018, American Registry for Internet Numbers, Ltd." ]
  } ],
  "arin_originas0_networkSearchResults" : [ {
    "handle" : "NET-XXXX-XXX-1",
    "startAddress" : "2001:db8::",
    "endAddress" : "2001:db8:0::ffff",
    "ipVersion" : "v6",
    "name" : "SAMPLE-IPV6",
    "parentHandle" : "NET-XXYY-XXX-0",
    "events" : [ {
      "eventAction" : "last changed",
      "eventDate" : "2012-02-24T09:44:34-05:00"
    }, {
      "eventAction" : "registration",
      "eventDate" : "2005-03-14T11:31:08-05:00"
    } ],
    "links" : [ {
      "value" : "https://rdap.arin.net/registry/arin_originas0_networksbyoriginas/64496",
      "rel" : "self",
      "type" : "application/rdap+json",
      "href" : "https://rdap.arin.net/registry/ip/2001:db8::"
    }, {
      "value" : "https://rdap.arin.net/registry/arin_originas0_networksbyoriginas/64496",
      "rel" : "alternate",
      "type" : "application/xml",
      "href" : "https://whois.arin.net/rest/net/ NET-XXXX-XXX-1"
    } ],
    "entities" : [ {
      "handle" : "ARIN",
      "vcardArray" : [ "vcard", [ [ "version", { }, "text", "4.0" ], [ "fn", { }, "text", "ARIN" ], [ "adr", {
        "label" : "P.O. BOX 232290\Chantilly\nVA\n20120\nUnited States"
      }, "text", [ "", "", "", "", "", "", "" ] ], [ "kind", { }, "text", "org" ] ] ],
      "roles" : [ "registrant" ],
      "links" : [ {
        "value" : "https://rdap.arin.net/registry/arin_originas0_networksbyoriginas/64496",
        "rel" : "self",
        "type" : "application/rdap+json",
        "href" : "https://rdap.arin.net/registry/entity/ARIN"
      }, {
        "value" : "https://rdap.arin.net/registry/arin_originas0_networksbyoriginas/64496",
        "rel" : "alternate",
        "type" : "application/xml",
        "href" : "https://whois.arin.net/rest/org/ARIN"
      } ],
      "events" : [ {
        "eventAction" : "last changed",
        "eventDate" : "2017-12-21T13:24:44-05:00"
      }, {
        "eventAction" : "registration",
        "eventDate" : "2000-03-30T00:00:00-05:00"
      } ],

ASN

Queries for information regarding ASN registrations are of the form:

<rdap-url>/autnum/<asn> where <asn> is an ASN, without the AS prefix.

Query Example

https://rdap.arin.net/registry/autnum/64496

Sample Output

# NicInfo v.1.4.1

# Result type is ASNUMBER.

[ RESPONSE DATA ]  
  1= AS64496
     `--- 1= Internet Assigned Numbers Authority ( IANA )
          |--- 1= Internet Corporation for Assigned Names and Number ( IANA-ARIN )
          `--- 2= ICANN ( IANA-IP-ARIN )

            [ AS NUMBER ]
                   Handle:  AS64496
          Start AS Number:  64496
            End AS Number:  64511
             Last Changed:  Wed, 14 Jan 2009 18:10:12 -0500
             Registration:  Wed, 03 Dec 2008 00:00:00 -0500
                  Remarks:  -- Registration Comments --
                        1:  Reserved for use in documentation and sample code [RFC5398]

               [ ENTITY ]
                   Handle:  IANA
              Common Name:  Internet Assigned Numbers Authority
                    Roles:  Registrant
             Last Changed:  Fri, 31 Aug 2012 13:32:25 -0400

               [ ENTITY ]
                   Handle:  IANA-ARIN
              Common Name:  Internet Corporation for Assigned Names and Number
             Organization:  Internet Corporation for Assigned Names and Number
                    Email:  res-ip@iana.org
                    Phone:  +1-310-823-9358 ( work, voice )
                    Roles:  Administrative
                   Status:  Validated
             Last Changed:  Mon, 11 Nov 2013 13:27:24 -0500

               [ ENTITY ]
                   Handle:  IANA-IP-ARIN
              Common Name:  ICANN
             Organization:  ICANN
                    Email:  abuse@iana.org
                    Phone:  +1-310-301-5820 ( work, voice )
                    Roles:  Technical, Abuse
                   Status:  Validated
             Last Changed:  Mon, 11 Aug 2014 12:22:29 -0400
             Registration:  Sun, 24 Aug 2003 23:00:00 -0400
                  Remarks:  -- Registration Comments --
                        1:  Think we're attacking you? Please look here:  
                        2:  http://www.iana.org/abuse

POC or Organization Identifier (Org ID)

Queries for information about entities (POCs and Org IDs) are of the form:

<rdap-url>/entity/<handle>

where the <handle> parameter represents the POC or Org ID handle (e.g., KOSTE-ARIN).

Query Example

https://rdap.arin.net/registry/entity/koste-arin

Sample Output

# NicInfo v.1.4.1

# Result type is ENTITYHANDLE.
[ RESPONSE DATA ]  

               [ ENTITY ]
                   Handle:  KOSTE-ARIN
              Common Name:  Mark Kosters
                    Email:  markk@kosters.net
                    Email:  markk@bjmk.com
                    Phone:  +1-703-227-9870 ( work, voice )
                   Status:  Validated
             Last Changed:  Tue, 23 Oct 2018 12:14:22 -0400
             Registration:  Fri, 02 Oct 2009 11:54:45 -0400
                  Remarks:  -- Registration Comments --
                        1:  I'm really MAK21-ARIN

Nameserver

Querying for nameservers (as specified in RFC 0952 and RFC 1123) is supported by domain registries, but is not supported for ARIN’s registration data through RDAP.

Where to Go for Additional Help with RDAP

For full details and specifications, please view the following IETF Internet Request for Comments (RFC) documents:

  • RFC 7480 - HTTP Usage in the Registration Data Access Protocol (RDAP)
  • RFC 7481 - Security Services for the Registration Data Access Protocol (RDAP)
  • RFC 7482 - Registration Data Access Protocol (RDAP) Query Format
  • RFC 7483 - JSON Responses for the Registration Data Access Protocol (RDAP)
  • RFC 7484 - Finding the Authoritative Registration Data (RDAP) Service
  • RFC 7485 - Inventory and Analysis of WHOIS Registration Objects

If you need help using the RDAP service, ARIN recommends subscribing and posting to the arin-tech-discuss mailing list. You may wish to check the mailing list archives before submitting your question.

Registration Services Help Desk
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