INTERNET-DRAFT Reserved TLDs May 1998 Expires November 1998 Reserved Top Level DNS Names -------- --- ----- --- ----- Donald E. Eastlake 3rd Aliza R. Panitz Status of This Document This draft is file name draft-ietf-dnsind-test-tlds-09.txt. Distribution of this document is unlimited. Comments should be sent to the DNS mailing list or to the authors. This document is an Internet-Draft. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. Internet-Drafts are draft documents valid for a maximum of six months. Internet-Drafts may be updated, replaced, or obsoleted by other documents at any time. It is not appropriate to use Internet- Drafts as reference material or to cite them other than as a ``working draft'' or ``work in progress.'' To view the entire list of current Internet-Drafts, please check the "1id-abstracts.txt" listing contained in the Internet-Drafts Shadow Directories on ftp.is.co.za (Africa), ftp.nordu.net (Northern Europe), ftp.nis.garr.it (Southern Europe), munnari.oz.au (Pacific Rim), ftp.ietf.org (US East Coast), or ftp.isi.edu (US West Coast). [Changes in this draft from the last version resulted from further discussion with IANA.] D. Eastlake, A. Panitz [Page 1] INTERNET-DRAFT Reserved TLDs Abstract To reduce the likelihood of conflict and confusion, a number of top level domain names are reserved for use in private testing, as examples in documentation, and the like. In addition, a few second level domain names reserved for use as examples are documented. Table of Contents Status of This Document....................................1 Abstract...................................................2 Table of Contents..........................................2 1. Introduction............................................3 2. TLDs for Testing, & Documentation Examples..............3 3. Reserved Example Second Level Domain Names..............4 4. Security Considerations.................................4 References.................................................5 Authors Addresses..........................................5 Expiration and File Name...................................5 D. Eastlake, A. Panitz [Page 2] INTERNET-DRAFT Reserved TLDs 1. Introduction The global Internet Domain Name System is documented in [RFC 1034, 1035, 1591] and numerous additional Requests for Comment. It defines a tree of names starting with root, ".", immediately below which are top level domain names such as ".com" and ".us". Below top level domain names there are normally additional levels of names. 2. TLDs for Testing, & Documentation Examples There is a need for top level domain (TLD) names that can be used for creating names which, without fear of conflicts with current or future actual TLD names in the global DNS, can be used for private testing of existing DNS related code, examples in documentation, DNS related experimentation, invalid DNS names, or other similar uses. For example, without guidance, a site might set up some local additional unused top level domains for testing of its local DNS code and configuration. Later, these TLDs might come into actual use on the global Internet. As a result, local attempts to reference the real data in these zones could be thwarted by the local test versions. Or test or example code might be written that accesses a TLD that is in use with the thought that the test code would only be run in a restricted testbed net or the example never actually run. Later, the test code could escape from the testbed or the example be actually coded and run on the Internet. Depending on the nature of the test or example, it might be best for it to be referencing a TLD permanently reserved for such purposes. To safely satisfy these needs, four domain names are reserved as listed and described below. .test .example .invalid .localhost ".test" is particularly recommended for use in testing of current or new DNS related code. ".example" is particularly recommended for use in documentation or as examples. ".invalid" is intended for use in online construction of domain names that are sure to be invalid and which are obviously invalid. By appending ".invalid" to a domain name, you are sure of constructing a name that is not valid. D. Eastlake, A. Panitz [Page 3] INTERNET-DRAFT Reserved TLDs The ".localhost" TLD has traditionally been staticly defined in host DNS implementations as having an A record pointing to the loop back IP address and is reserved for such use. Any other use would conflict with widely deployed code which assumes this use. [ At the time of the issuance of this draft as an RFC, IANA will determine which, if any, of the above names will actually be entered into the IETF recommended root zone with a single TXT RR for each that will contain the string Reserved, see RFC nnnn. or such other information as IANA determines. This text within square brackets will be modified to indicate which names are actually entered in root and what RR or RRs will be stored under them. [Note to RFC-Editor: replace nnnn above with the number of the RFC this draft gets issued as.] ] 3. Reserved Example Second Level Domain Names The Internet Assigned Numbers Authority (IANA) also currently has the following second level domain names reserved which can be used as examples. example.com example.net example.org 4. Security Considerations Confusion and conflict can be caused by the use of a current or future top level domain name in experimentation or testing, as an example in documentation, to indicate invalid names, or as a synonym for the loop back address. Test and experimental software can escape and end up being run against the global operational DNS. Even examples used "only" in documentation can end up being coded and released or cause conflicts due to later real use and the possible acquisition of intellectual property rights in such "example" names. The reservation of several top level domain names for these purposes will minimize such confusion and conflict. D. Eastlake, A. Panitz [Page 4] INTERNET-DRAFT Reserved TLDs References RFC 1034 - P. Mockapetris, "Domain names - concepts and facilities", 11/01/1987. RFC 1035 - P. Mockapetris, "Domain names - implementation and specification", 11/01/1987. RFC 1591 - J. Postel, "Domain Name System Structure and Delegation", 03/03/1994. Authors Addresses Donald E. Eastlake 3rd CyberCash, Inc. 318 Acton Street Carlisle, MA 01741 USA Telephone: +1 978 287 4877 +1 703 620-4200 (main office, Reston, VA) FAX: +1 978 371 7148 email: dee@cybercash.com Aliza R. Panitz AccessAbility Internet Services, Inc. 12515 Greenbriar Road Potomac, MD 20854 USA Telephone: +1 301 983-3547 FAX: +1 301 983-4899 email: buglady@ability.net Expiration and File Name This draft expires November 1998. Its file name is draft-ietf-dnsind-test-tlds-09.txt. D. Eastlake, A. Panitz [Page 5]