INTERNET-DRAFT Test and Example TLDs January 1998 Expires July 1998 Test and Example Top Level DNS Names ---- --- ------- --- ----- --- ----- Donald E. Eastlake 3rd Aliza R. Panitz Status of This Document This draft, file name draft-ietf-dnsind-test-tlds-07.txt, is intended to be become a Best Current Practice RFC. 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 learn the current status of any Internet-Draft, please check the 1id-abstracts.txt listing contained in the Internet-Drafts Shadow Directories on ds.internic.net (East USA), ftp.isi.edu (West USA), nic.nordu.net (North Europe), ftp.nis.garr.it (South Europe), munnari.oz.au (Pacific Rim), or ftp.is.co.za (Africa). 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. D. Eastlake, A. Panitz [Page 1] INTERNET-DRAFT Test and Example TLDs Table of Contents Status of This Document....................................1 Abstract...................................................1 Table of Contents..........................................2 1. Introduction............................................3 2. TLDs for Testing and Documentation Examples.............3 3. Reserved Example Second Level Domain Names..............6 4. Security Considerations.................................6 References.................................................7 Author's Addresses.........................................7 Expiration and File Name...................................7 D. Eastlake, A. Panitz [Page 2] INTERNET-DRAFT Test and Example 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 and Documentation Examples There is a need for top level domain (TLD) names that can safely be used in private testing, as examples in documentation, and for experimentation, without fear of conflicts with actual top level domain names in the global DNS, or which should be reserved to avoid confusion. 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 restricted testbed net or the example never actually run. Later, the test code could esacpe 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, after its esacpe, to be referencing a mostly empty TLD reserved for such purposes. To satisfy these needs, domain names are reserved as described below. It is thought best to allocate a reasonably large number of names of different lengths now to reduce the probability of a need for further top level domain name creation and assignment for this purpose in the foreseeable future. On the other hand, there is no reason to horde an excessive number of names. There was a working group consensus that the answer to balancing these requirmenets is fourty two names [GUIDE]. The following twelve top level domain names are reserved. D. Eastlake, A. Panitz [Page 3] INTERNET-DRAFT Test and Example TLDs .xy .xz .nil .tld .link .site .test .bogus .example .invalid .localhost .asixtythreecharacterstopleveldomainnamewhichisthelongestallowed Note: two letter top level domain names are reserved for ISO 3166 / Universal Postal Union two letter country codes. However, ISO 3166 reserves all two letter codes beginning with "x" for local use and states that they will never be assigned to a country. These names are available for use in testing or as examples in documentation except for ".invalid", ".link", and ".localhost". ".invalid" is intended for use in online construction of domain names that are sure to be invalid. By appending ".invalid" to a domain name, you are sure of constructing a name that is not valid. ".link" is reserved to avoid confusion with the "link.local" domain provided in [draft-ietf-dnsind-local-names-*] and should not be used. 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. The TLDs ".xy", ".nil", and ".test" are particularly recommended for use in testing. If a larger number of test names is needed, the numeric suffix names listed below should be used. The TLDs ".xz", ".tld", ".site", ".bogus", and ".example" are particularly recommended for use in documentation or as examples. If a larger number of names is needed in documentation or as examples, the numeric suffix names listed below should be used. The above twelve names will be added to the root with a single type TXT RR under each. The RDATA for these TXT RRs will contain the single string Reserved, see RFC nnnn. [Note to RFC-Editor: replace nnnn above with the number of the RFC this draft gets issued as and delete this note] Other data will not be stored under these names in the root zone D. Eastlake, A. Panitz [Page 4] INTERNET-DRAFT Test and Example TLDs except that the loopback A and AAAA [RFC 1886] resource records may be stored under .localhost. However, to assure proper operation of hosts even when unable to access a root server, .localhost must still be locally staticly configured. In addition, the thirty domain names formed by appending the digits 0 through 9 to "tld", "test", and "example", as listed below, are also reserved for test and documentation use; however, since there are currently no TLDs with digits in them and the presence of these names without the digit suffix should provide notice, it is not intended that these thirty additional TLDs be entered into the root zone at this time. .tld0 .test0 .example0 .tld1 .test1 .exmaple1 .tld2 .test2 .example2 .tld3 .test2 .example2 .tld4 .test4 .example4 .tld5 .test5 .exmaple5 .tld6 .test6 .example6 .tld7 .test7 .example7 .tld8 .test8 .example8 .tld9 .test9 .example9 D. Eastlake, A. Panitz [Page 5] INTERNET-DRAFT Test and Example TLDs 3. Reserved Example Second Level Domain Names The Internet Assigned Numbers Authority (IANA) has also reserved the following second level domain names 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 potential future top level domain name in testing, experimentation, as an example in documentation, or the like. 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 6] INTERNET-DRAFT Test and Example TLDs References GUIDE - D. Adams, "The Hitchhiker's Guide to the Galaxy", 1989. 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. RFC 1886 - S. Thomson, C. Huitema, "DNS Extensions to support IP version 6", December 1995. draft-ietf-dnsind-local-names-* - D. Eastlake, "Local DNS Names". Author's 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 July 1998. Its file name is draft-ietf-dnsind-test-tlds-07.txt. D. Eastlake, A. Panitz [Page 7]