WHOIS Protocol Specification
RFC 3912

Document Type RFC - Draft Standard (September 2004; No errata)
Obsoletes RFC 812, RFC 954
Was draft-daigle-rfc954bis (individual in app area)
Last updated 2013-03-02
Stream IETF
Formats plain text pdf html
Stream WG state (None)
Consensus Unknown
Document shepherd No shepherd assigned
IESG IESG state RFC 3912 (Draft Standard)
Telechat date
Responsible AD Ted Hardie
Send notices to (None)
Network Working Group                                          L. Daigle
Request for Comments: 3912                                VeriSign, Inc.
Obsoletes: 954, 812                                       September 2004
Category: Standards Track

                      WHOIS Protocol Specification

Status of this Memo

   This document specifies an Internet standards track protocol for the
   Internet community, and requests discussion and suggestions for
   improvements.  Please refer to the current edition of the "Internet
   Official Protocol Standards" (STD 1) for the standardization state
   and status of this protocol.  Distribution of this memo is unlimited.

Copyright Notice

   Copyright (C) The Internet Society (2004).


   This document updates the specification of the WHOIS protocol,
   thereby obsoleting RFC 954.  The update is intended to remove the
   material from RFC 954 that does not have to do with the on-the-wire
   protocol, and is no longer applicable in today's Internet.  This
   document does not attempt to change or update the protocol per se, or
   document other uses of the protocol that have come into existence
   since the publication of RFC 954.

1.  Introduction

   WHOIS is a TCP-based transaction-oriented query/response protocol
   that is widely used to provide information services to Internet
   users.  While originally used to provide "white pages" services and
   information about registered domain names, current deployments cover
   a much broader range of information services.  The protocol delivers
   its content in a human-readable format.  This document updates the
   specification of the WHOIS protocol, thereby obsoleting RFC 954 [1].

   For historic reasons, WHOIS lacks many of the protocol design
   attributes, for example internationalisation and strong security,
   that would be expected from any recently-designed IETF protocol.
   This document does not attempt to rectify any of those shortcomings.
   Instead, this memo documents the WHOIS protocol as it is.  In some
   areas, this document does document particular well known shortcomings
   of the WHOIS protocol.  The discussion of possible protocols to carry
   out these functions, with updated capabilities to address the

Daigle                      Standards Track                     [Page 1]
RFC 3912              WHOIS Protocol Specification        September 2004

   shortcomings, is being addressed in a separate IETF activity (CRISP
   Working Group).

2.  Protocol Specification

   A WHOIS server listens on TCP port 43 for requests from WHOIS
   clients.  The WHOIS client makes a text request to the WHOIS server,
   then the WHOIS server replies with text content.  All requests are
   terminated with ASCII CR and then ASCII LF.  The response might
   contain more than one line of text, so the presence of ASCII CR or
   ASCII LF characters does not indicate the end of the response.  The
   WHOIS server closes its connection as soon as the output is finished.
   The closed TCP connection is the indication to the client that the
   response has been received.

3.  Protocol Example

   If one places a request of the WHOIS server located at whois.nic.mil
   for information about "Smith", the packets on the wire will look

   client                           server at whois.nic.mil

   open TCP   ---- (SYN) ------------------------------>
              <---- (SYN+ACK) -------------------------
   send query ---- "Smith<CR><LF>" -------------------->
   get answer <---- "Info about Smith<CR><LF>" ---------
              <---- "More info about Smith<CR><LF>" ----
   close      <---- (FIN) ------------------------------
              ----- (FIN) ----------------------------->

4.  Internationalisation

   The WHOIS protocol has not been internationalised.  The WHOIS
   protocol has no mechanism for indicating the character set in use.
   Originally, the predominant text encoding in use was US-ASCII.  In
   practice, some WHOIS servers, particularly those outside the USA,
   might be using some other character set either for requests, replies,
   or both.  This inability to predict or express text encoding has
   adversely impacted the interoperability (and, therefore, usefulness)
   of the WHOIS protocol.

5.  Security Considerations

   The WHOIS protocol has no provisions for strong security.  WHOIS
   lacks mechanisms for access control, integrity, and confidentiality.
   Accordingly, WHOIS-based services should only be used for information
   which is non-sensitive and intended to be accessible to everyone.

Daigle                      Standards Track                     [Page 2]
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