Network Working Group F. Ellermann Internet-Draft xyzzy Obsoletes: 2606 (if approved) June 6, 2008 Intended status: BCP Expires: December 8, 2008 Reserved Top Level DNS Names draft-ellermann-idnabis-test-tlds-01 Status of this Memo By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she becomes aware will be disclosed, in accordance with Section 6 of BCP 79. 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 and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on December 8, 2008. Abstract To reduce the likelihood of conflict and confusion, a few 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. Editorial note This note and the document history (Appendix A) should be removed before publication. Ellermann Expires December 8, 2008 [Page 1] Internet-Draft Reserved Top Level DNS Names June 2008 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. TLDs for Testing, & Documentation Examples . . . . . . . . . . 3 2.1. ".example" . . . . . . . . . . . . . . . . . . . . . . . . 3 2.2. ".invalid" . . . . . . . . . . . . . . . . . . . . . . . . 3 2.3. ".localhost" . . . . . . . . . . . . . . . . . . . . . . . 4 2.4. ".test" . . . . . . . . . . . . . . . . . . . . . . . . . . 4 3. Reserved Example Second Level Domain Names . . . . . . . . . . 4 4. Internationalization Considerations . . . . . . . . . . . . . . 4 5. Security Considerations . . . . . . . . . . . . . . . . . . . . 5 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 5 7. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . 5 8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 6 8.1. Normative References . . . . . . . . . . . . . . . . . . . 6 8.2. Informative References . . . . . . . . . . . . . . . . . . 6 Appendix A. Document History . . . . . . . . . . . . . . . . . . . 6 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 7 Intellectual Property and Copyright Statements . . . . . . . . . . 8 Ellermann Expires December 8, 2008 [Page 2] Internet-Draft Reserved Top Level DNS Names June 2008 1. Introduction The global Internet Domain Name System is documented in [RFC1034], [RFC1035], [RFC1591], [RFC3696], and numerous additional Requests for Comments. 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. The key words "MAY", "RECOMMENDED", and "SHOULD" in this memo are to be interpreted as described in [RFC2119]. 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. 2.1. ".example" ".example" is RECOMMENDED for use in documentation or as examples. 2.2. ".invalid" ".invalid" is intended for use in online construction of domain names that are sure to be invalid, and for which it is obvious at a glance that they are invalid. Applications MAY treat ".invalid" as what the name says. Ellermann Expires December 8, 2008 [Page 3] Internet-Draft Reserved Top Level DNS Names June 2008 2.3. ".localhost" The ".localhost" TLD has traditionally been statically 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. 2.4. ".test" ".test" is RECOMMENDED for use in testing of current or new DNS related code. Applications SHOULD treat ".test" like any other TLD; a special handling could defeat the purpose of a test. 3. Reserved Example Second Level Domain Names The Internet Assigned Numbers Authority (IANA) also reserves the three second level domain names ".example.com", ".example.net", and ".example.org", which can be used in examples as explained in Section 2.1. When TLDs offer further second level domains for examples, the TLD administrators are encouraged to publish the relevant policies in their TLD as an informational RFC. The second level domain names "nic", "whois", and "www" are often reserved or used for the purposes of the TLD administration. As with second level domains for examples this can be an issue in the case of a transfer to a new administration. 4. Internationalization Considerations In 2007 IANA created eleven TLDs for tests of Internationalized Domain Names (IDN). The A-labels and corresponding languages are listed below; see [RFC3490] or its [IDNAbis] successor for details about IDN. Applications SHOULD treat these IDN test TLDs as explained in Section 2.4. Ellermann Expires December 8, 2008 [Page 4] Internet-Draft Reserved Top Level DNS Names June 2008 ".xn--0zwm56d" Chinese (simplified) ".xn--11b5bs3a9aj6g" Hindi ".xn--80akhbyknj4f" Russian ".xn--9t4b11yi5a" Korean ".xn--deba0ad" Yiddish ".xn--g6w251d" Chinese (traditional) ".xn--hgbk6aj7f53bba" Persian ".xn--hlcj6aya9esc7a" Tamil ".xn--jxalpdlp" Greek ".xn--kgbechtv" Arabic ".xn--zckzah" Japanese 5. 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 minimizes such confusion and conflict. 6. IANA Considerations IANA reserves the TLDs ".example", ".invalid", ".localhost", ".test", and eleven IDN test TLDs as noted above. IANA reserves the second level domains ".example.com", ".example.net", and ".example.org". IANA creates a public registry of reserved TLDs; this can be done alongside existing IANA TLD registries at the discretion of IANA. Additional reserved TLDs require IETF review as specified in [RFC5226] in conjunction with [RFC2860]. 7. Acknowledgments This memo contains major parts of [RFC2606] written by Donald E. Eastlake and Aliza R. Panitz. John C. Klensin suggested clarifying the guidelines for examples in RFCs. Thanks to Tony Hansen, and TBD for their feedback, contributions, or encouragement. Ellermann Expires December 8, 2008 [Page 5] Internet-Draft Reserved Top Level DNS Names June 2008 8. References 8.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an IANA Considerations Section in RFCs", BCP 26, RFC 5226, May 2008. 8.2. Informative References [RFC1034] Mockapetris, P., "Domain names - concepts and facilities", STD 13, RFC 1034, November 1987. [RFC1035] Mockapetris, P., "Domain names - implementation and specification", STD 13, RFC 1035, November 1987. [RFC1591] Postel, J., "Domain Name System Structure and Delegation", RFC 1591, March 1994. [RFC2606] Eastlake, D. and A. Panitz, "Reserved Top Level DNS Names", BCP 32, RFC 2606, June 1999. [RFC2860] Carpenter, B., Baker, F., and M. Roberts, "Memorandum of Understanding Concerning the Technical Work of the Internet Assigned Numbers Authority", RFC 2860, June 2000. [RFC3490] Faltstrom, P., Hoffman, P., and A. Costello, "Internationalizing Domain Names in Applications (IDNA)", RFC 3490, March 2003. [RFC3696] Klensin, J., "Application Techniques for Checking and Transformation of Names", RFC 3696, February 2004. [IDNAbis] IETF, "Internationalized Domain Names in Applications (Revised)", April 2008, . Appendix A. Document History Changes in version 01: o Various editorial issues found by Tony Hansen fixed. Ellermann Expires December 8, 2008 [Page 6] Internet-Draft Reserved Top Level DNS Names June 2008 o Added [IDNAbis] reference. The author believes that the IETF is not entitled to decree that "example.edu" belongs to the set of three example-SLDs reserved by IANA. Changes in version 00: o Derived from [RFC2606] to resolve a dispute about the use of e-mail addresses in RFC examples, adding the eleven new IDN test TLDs. Author's Address Frank Ellermann xyzzy Hamburg, Germany Email: hmdmhdfmhdjmzdtjmzdtzktdkztdjz@gmail.com URI: http://purl.net/xyzzy/ Ellermann Expires December 8, 2008 [Page 7] Internet-Draft Reserved Top Level DNS Names June 2008 Full Copyright Statement Copyright (C) The IETF Trust (2008). This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights. This document and the information contained herein are provided on an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Intellectual Property The IETF takes no position regarding the validity or scope of any Intellectual Property Rights or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; nor does it represent that it has made any independent effort to identify any such rights. Information on the procedures with respect to rights in RFC documents can be found in BCP 78 and BCP 79. Copies of IPR disclosures made to the IETF Secretariat and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementers or users of this specification can be obtained from the IETF on-line IPR repository at http://www.ietf.org/ipr. The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights that may cover technology that may be required to implement this standard. Please address the information to the IETF at ietf-ipr@ietf.org. Acknowledgment This document was produced using xml2rfc v1.33 (of http://xml.resource.org/) from a source in RFC-2629 XML format. Ellermann Expires December 8, 2008 [Page 8]