INTERNET-DRAFT L. Masinter, J. Gettys, B. Carpenter draft-masinter-url-ipv6-02 Expires six months after publication date April 15, 1999 An ".ipv6" Top Level Pseudo-Domain Status of this Memo This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC 2026. 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 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. Copyright Notice Copyright (C) The Internet Society (1999). All Rights Reserved. Abstract The normal textual representation for IPv6 addresses as a set of colon-separated hexadecimal numbers does not work well with most deployed URL-parsing software. This document describes an alternate format which will pass unharmed through most URL-parsing software. 1. Introduction The normal textual representation for IPv6 addresses as a set of colon-separated hexadecimal numbers does not work well with most deployed URL-parsing software. This document describes an alternate format which will pass unharmed through most URL-parsing software. Rather than describing an alternative syntax for IPv6 addresses only within URLs, it proposes a pseudo-domain ".ipv6" for using a domain-name-like syntax that actually represents the literal IPv6 address. 2. Background The standard representation for IPv6 addresses in text is defined in section 2.2 of [RFC2373] ("Text Representation of Addresses"). This representation uses hexadecimal values separated by colon ":", double colon "::", and optionally ending period-separated decimal values for the four low-order 8-bit pieces of the address. Unfortunately, using this IPv6 syntax within URLs [RFC2396] would be disruptive for many applications. Within the "hostport" section of the generic URI syntax, the colon is used to separate the host name or address from an (optional) port number. Thus, in some addresses, a colon followed by a decimal number could ambiguously be interpreted as a port designator or as a part of the IPv6 address. Even if there were no ambiguity, this syntax is incompatible with a many deployed applications that parse (but do not resolve) URLs, including many CGI scripts, robots, search engines, and so forth. 3. Syntax This specification defines a simple, safe representation for IPv6 addresses which can be used within URLs and also in other contexts. It does so by defining a syntax which will look like a domain name to otherwise unaware software. The syntax is best described as a transformation of the normal IPv6 syntax as defined in section 2.2 of [RFC2373]; starting with such an address: 1) replace every colon ":" with a "-" 2) append ".ipv6" to the end Thus, an HTTP service available at port 70 of IPv6 address "ABCD:EF01::2345:10.9.8.7" could be written as http://ABCD-EF01--2345-10.9.8.7.ipv6:70/ This syntax should always be used. Internet software that resolves host names and addresses in URLs should be modified to recognize the "ipv6" pseudo-domain. 4. Implementation considerations It would be useful for systems to uniformly recognize the "ipv6" pseudo-domain throughout, e.g., as a special case within "gethostbyname". [RFC 2133]. 5. IANA considerations IANA is requested to reserve the "ipv6" top level pseudo-domain for the purpose outlined in this memo. 6. References [RFC2396] R. Fielding, L. Masinter, T. Berners-Lee, "Uniform Resource Identifiers: Generic Syntax", August, 1998. [RFC2373] R. Hinden, S. Deering. "IP Version 6 Addressing Architecture", July, 1998. [RFC2133] R. Gilligan, S. Thomson, J. Bound, W.Stevens. "Basic Socket Interface Extensions for IPv6". 7. Authors' Addresses Larry Masinter Xerox Palo Alto Research Center 3333 Coyote Hill Road Palo Alto, CA 94034, USA Fax: +1 650 812 4365 EMail: masinter@parc.xerox.com James Gettys MIT Laboratory for Computer Science 545 Technology Square Cambridge, MA 02139, USA Fax: +1 617 258 8682 Email: jg@w3.org Brian Carpenter IBM United Kingdom Laboratories MP 185, Hursley Park Winchester, Hampshire SO21 2JN, UK Email: brian@hursley.ibm.com 7. Full Copyright Statement Copyright (C) The Internet Society (1999). All Rights Reserved. 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