Information About

Whois




The WHOIS system originated as a method that system administrators could use to look up information to contact other IP address or Domain Name administrators (almost like a " White Pages "). The use of the data that is returned from query responses has evolved from those origins into a variety of both altruistic (such as a Certificate Authority validating the registration for ecommerce https) and nefarious uses (such as bulk Unsolicited Email campaigns).

WHOIS has a sister protocol standard called RWhois .


THIN AND THICK LOOKUPS

There are two ways that WHOIS information may be stored: thick or thin. With the thick model, one WHOIS server stores the WHOIS information from all the registrars for the particular set of data (so that one WHOIS server can respond with WHOIS information on all .org domains, for example). With the thin model, one WHOIS server stores the name of the WHOIS server of a registrar that has the full details on the data being looked up (such as the .com WHOIS servers, which refer the WHOIS query to the registrar that the domain was registered from). The thick model usually ensures consistent data and slightly faster lookups (since only one WHOIS server needs to be contacted).

If a WHOIS client does not understand the information being returned, the results of a thin lookup (which include the WHOIS server of the registrar, and perhaps a few other necessary details) will be displayed to the end user. If the WHOIS client understood how to deal with this situation, it would display the full information from the registrar. Unfortunately, there is no standard in the WHOIS protocol for determining how to distinguish the thin model from the thick model.

Exact implementation of which records are stored varies between Domain Name Registries . Some Top-level Domain s, including .com and .net , operate a thin WHOIS, allowing the various domain registrars the ability to maintain their own customers' data. Other registries, including .org , operate a thick model.


EXAMPLE QUERY

Below is the result of a WHOIS query on Wikipedia.org :

Domain ID:D51687756-LROR
Domain Name:WIKIPEDIA.ORG
Created On:13-Jan-2001 00:12:14 UTC
Last Updated On:01-Mar-2006 12:39:33 UTC
Expiration Date:13-Jan-2015 00:12:14 UTC
Sponsoring Registrar:Go Daddy Software, Inc. (R91-LROR)
Status:CLIENT DELETE PROHIBITED
Status:CLIENT RENEW PROHIBITED
Status:CLIENT TRANSFER PROHIBITED
Status:CLIENT UPDATE PROHIBITED
Registrant ID:GODA-09495921
Registrant Name:Wikimedia Foundation
Registrant Organization:Wikimedia Foundation Inc.
Registrant Street1:204 37th Ave N, #330
Registrant Street2:
Registrant Street3:
Registrant City:St. Petersburg
Registrant State/Province:Florida
Registrant Postal Code:33704
Registrant Country:US
Registrant Phone:+1.7272310101
Registrant Phone Ext.:
Registrant FAX:
Registrant FAX Ext.:
Registrant Email:noc@wikimedia.org
Admin ID:GODA-29495921
Admin Name:Jimmy Wales
Admin Organization:Wikimedia Foundation
Admin Street1:204 37th Ave. N. #330
Admin Street2:
Admin Street3:
Admin City:St. Petersburg
Admin State/Province:Florida
Admin Postal Code:33704
Admin Country:US
Admin Phone:+1.7276441636
Admin Phone Ext.:
Admin FAX:
Admin FAX Ext.:
Admin Email:jwales@bomis.com
Tech ID:GODA-19495921
Tech Name:Jason Richey
Tech Organization:Wikimedia Foundation
Tech Street1:19589 Oneida Rd.
Tech Street2:
Tech Street3:
Tech City:Apple Valley
Tech State/Province:California
Tech Postal Code:92307
Tech Country:US
Tech Phone:+1.7604869194
Tech Phone Ext.:
Tech FAX:
Tech FAX Ext.:
Tech Email:jasonr@bomis.com
Name Server:NS0.WIKIMEDIA.ORG
Name Server:NS1.WIKIMEDIA.ORG
Name Server:NS2.WIKIMEDIA.ORG


HISTORY

When the Internet was emerging out of the ARPANET entity, there was only one organization that handled all domain registrations, which was DARPA itself. The process of registration was established in RFC 920. WHOIS was standardized in the early 1980s to look-up domains, people and other resources related domain and number registrations. Because all registration was done by one organization in that time, one centralized server was used for WHOIS queries. This made looking-up information very easy.

Early WHOIS servers were highly permissive and would allow wild-card searches. You could do a WHOIS lookup on a person's last name and get all the individual people who had a registered handle. You could do a query on a keyword and see all registered domains containing that keyword. You could even query a given administrative contact and see all domains they were associated with. Due to the advent of the commercialized Internet, Multiple Registrars and unethical spammers, such permissive searching is no longer available.

Initially, while ARPANET faded away in the late 1980s, responsibility of domain registration remained with DARPA . UUNet began offering domain registration service, however they simply handled the paperwork for you and still had to deal with DARPA's Network Information Center (NIC). Then the National Science Foundation directed that management of Internet domain registration would be handled by commercial, 3rd party entities. InterNIC was formed in 1993 under contract with the NSF, consisting of Network Solutions, Inc. , General Atomics, and AT&T . General Atomics' contract was cancelled after several years due to performance issues.

On December 1, 1999, management of .com, .net, and .org was turned over to ICANN and these popular TLDs were switched to a thin WHOIS model. Existing WHOIS clients stopped working at that time. The next day bw-whois was released as a command-line WHOIS client. A month later it had self-detecting CGI support so that the same program could operate a web-based WHOIS lookup, and an external TLD table to support multiple whois servers based on the TLD of the request. This eventually became the model of the modern whois client.

Currently, in 2005, there are many more generic top-level domains than there were in the early 1980s. There are also many, many more country-code top-level domains. This has led to a complex network of Domain Name Registrar s and registrar associations, especially as the management of Internet infrastructure has become more internationalized. As such, performing a WHOIS query on a domain requires knowing the correct, authoritative WHOIS server to use. Tools to do WHOIS proxy searches have become common, and there's a command-line whois client (jwhois) which uses a configuration file to map-out domain names and network blocks to their appropriate registrar.

In 2004, an IETF committee was formed to standardize a whole new way to look-up information on domain names and network numbers. The current working name for this proposed new standard is CRISP (Cross Registry Information Service Protocol).


QUERYING WHOIS SERVERS


Command-line clients

Originally the only method by which a WHOIS server could be contacted was to use a Command Line Interface text client. In most cases this was on a Unix or Unix-like platform. The WHOIS client software was (and still is) distributed as Open Source . Various commercial Unix implementations may use their own implementations (for example, Sun Solaris 7 has a WHOIS client authored by Sun).

A WHOIS command line client typically has options to choose which host to connect to for whois queries, with a default whois server being compiled in. Additional options may allow control of what port to connect on, displaying additional debugging data, or changing recursion/referral behavior.

Like most TCP/IP client/server applications, a WHOIS client takes the user input and then opens an IP socket to its destination server. The WHOIS protocol is used to establish a connection on the appropriate port and send the query. The client waits for a response from the server, which it then either returns to the end-user or uses to make additional queries. Much more detailed information on the WHOIS protocol can be found in the RFCs .

The GNU Project 's jwhois client, unlike many other WHOIS clients, uses an external configuration file to determine what WHOIS server to contact for a query. This moves some of the recursion/referral logic outside of the code and into a user-manageable file which is more adaptive to rapidly changing Internet infrastructure.


Graphical clients

The term "graphical client" may be a bit of a misnomer for a WHOIS client, since all the data to be derived from a WHOIS server is plain text, and the protocol is a relatively static one. There is not much interaction to do with a WHOIS server. In this context, the term "graphical client" is taken to mean a WHOIS client that runs as an application on a GUI OS and uses the OS's standard GUI for user interaction.

One popular and freely available WHOIS client for Windows is part of the Sam-Spade package , and allows for hotlinking of lookups (i.e. you can click on part of the results of a WHOIS query to generate a new query).

Another popular Windows WHOIS client is Active Whois . It combines WHOIS lookups with a DNS lookup for the host, and supports both thick and thin models. Like Sam-Spade, this client also supports hotlinked query results.


Web based clients

With the advent of the World Wide Web and especially the loosening up of the Network Solutions monopoly, looking up WHOIS information via the web has become quite common. Most early web-based WHOIS clients were merely front-ends to a command-line client, where the resulting output just got displayed on a webpage with little, if any, clean-up or formatting.

Nowadays, web based WHOIS clients usually perform the WHOIS queries directly and then format the results for display. Many such clients are proprietary, authored by domain name registrars such as Go Daddy or Network Solutions. However, there are Open Source clients such as the original GeekTools client or the much-improved Whois Proxy client.

The need for web-based clients came from the fact that command-line WHOIS clients largely existed only in the Unix and large computing worlds. Microsoft Windows and Macintosh computers had no WHOIS clients, so registrars had to find a way to provide access to WHOIS data for potential customers. Many end-users still rely on such clients, even though command line and graphical clients exist now for most home PC platforms.


Perl Modules

There are multiple modules available for Perl that work with WHOIS servers {Link without Title} . Many of them are not current and do not fully function with the current (2005) WHOIS server infrastructure. However, there is still much useful functionality to derive including looking up AS numbers and registrant contacts.


PROBLEMS

  • , are made easily accessible to anyone over the internet for most Top-level Domain s. Although some registrars offer private registrations (where the contact information of the registrar is shown), this sometimes means that the registrar is the legal owner (leasor) of the domain.

  • systems (where end users have to type in letters/numbers from a picture) and rate limiting systems.

  • , although this cannot be assumed anymore with international servers. This obviously will impact the usability of the WHOIS protocol in countries outside the USA, especially as Internationalized Domain Names are falling into wider use. A user can (and possibly ''will have to'' due to this limitation) use Punycode , but this leads to conversion problems as the punycode system is not easy for a regular user to grasp.

  • Lack of WHOIS server lists: There is no central list of WHOIS servers. Therefore, people writing WHOIS tools need to find their own list of WHOIS servers, and different WHOIS tools may contact different WHOIS servers. One of the few sources of a list of WHOIS servers can be found in the source of this page .

  • Different registrars' WHOIS servers return results in different formats, making automation of parsing WHOIS data difficult. While such automation has many legitimate uses (primarily for ISPs ), it also lends itself to use by Spammers and other people acting Unethical ly.



LIST OF WHOIS SERVER HIERARCHIES


As mentioned above there is no central list of WHOIS servers there are many. The following list aims to provide a list of hiearchies or software with whois server indexes. This list is not meant to be an ultimate list of whois servers, it is meant to list top of servers or whois clients which help to recurse and find the appropriate whois server to quiery. This list may change from time to time.

- who.is : Whois data gathered for top level domains worldwide, provides date for most cctld's and top level domains

- Uwhois : Referred to by internic.net. They provide their own Uwhois whois client and also a central server which does the recursion.

- Whois-servers.net : It is operated by Centergate. It provides a whois server which clients can query and recurse to other whois servers which contain the data. Many UNIX OS's refer to this set of servers to recurse.

- bw-whois : It is a whois client which comes with a list of the whois is servers responsible for each name space. This list is updated manually, the master is located here


SEE ALSO




EXTERNAL LINKS



Request For Comments ( Internet Standards Specifications )