Network Working Group
Request for Comments: 2732
Category: Standards Track
R. Hinden
Nokia
B. Carpenter
IBM
L. Masinter
AT&T
December 1999

Format for Literal IPv6 Addresses in URL's

Status of this Memo

This document specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "Internet Official Protocol Standards" (STD 1) for the standardization state and status of this protocol. Distribution of this memo is unlimited.

Copyright Notice

Copyright © The Internet Society (1999). All Rights Reserved.

Abstract

This document defines the format for literal IPv6 Addresses in URL's for implementation in World Wide Web browsers. This format has been implemented in the IPv6 versions of several widely deployed browsers including Microsoft Internet Explorer, Mozilla, and Lynx. It is also intended to be used in the IPv6 version of the service location protocol.

This document incudes an update to the generic syntax for Uniform Resource Identifiers defined in RFC 2396 [URL]. It defines a syntax for IPv6 addresses and allows the use of "[" and "]" within a URI explicitly for this reserved purpose.

1. Introduction

The textual representation defined for literal IPv6 addresses in [ARCH] is not directly compatible with URL's. Both use ":" and "." characters as delimiters. This document defines the format for literal IPv6 Addresses in URL's for implementation in World Wide Web browsers. The goal is to have a format that allows easy "cut" and "paste" operations with a minimum of editing of the literal address.

The format defined in this document has been implemented in the IPv6 versions of several widely deployed browsers including Microsoft Internet Explorer, Mozilla, and Lynx. It is also intended to be used in the IPv6 version of the service location protocol.

1.1 Requirements

The keywords MUST, MUST NOT, REQUIRED, SHALL, SHALL NOT, SHOULD, SHOULD NOT, RECOMMENDED, MAY, and OPTIONAL, if and where they appear in this document, are to be interpreted as described in [KEYWORDS].

World Wide Web browsers SHOULD implement the format of IPv6 literals in URL's defined in this document. Other types of applications and protocols that use URL's MAY use this format.

2. Literal IPv6 Address Format in URL's Syntax

To use a literal IPv6 address in a URL, the literal address should be enclosed in "[" and "]" characters. For example the following literal IPv6 addresses:

      FEDC:BA98:7654:3210:FEDC:BA98:7654:3210
      1080:0:0:0:8:800:200C:4171
      3ffe:2a00:100:7031::1
      1080::8:800:200C:417A
      ::192.9.5.5
      ::FFFF:129.144.52.38
      2010:836B:4179::836B:4179

would be represented as in the following example URLs:

      http://[FEDC:BA98:7654:3210:FEDC:BA98:7654:3210]:80/index.html
      http://[1080:0:0:0:8:800:200C:417A]/index.html
      http://[3ffe:2a00:100:7031::1]
      http://[1080::8:800:200C:417A]/foo
      http://[::192.9.5.5]/ipng
      http://[::FFFF:129.144.52.38]:80/index.html
      http://[2010:836B:4179::836B:4179]

3. Changes to RFC 2396

This document updates the generic syntax for Uniform Resource Identifiers defined in RFC 2396 [URL]. It defines a syntax for IPv6 addresses and allows the use of "[" and "]" within a URI explicitly for this reserved purpose.

The following changes to the syntax in RFC 2396 are made: (1) change the 'host' non-terminal to add an IPv6 option:

      host          = hostname | IPv4address | IPv6reference
      ipv6reference = "[" IPv6address "]"

where IPv6address is defined as in RFC2373 [ARCH].

(2) Replace the definition of 'IPv4address' with that of RFC 2373, as it correctly defines an IPv4address as consisting of at most three decimal digits per segment.

(3) Add "[" and "]" to the set of 'reserved' characters:

      reserved    = ";" | "/" | "?" | ":" | "@" | "&" | "=" | "+" |
      
                    "$" | "," | "[" | "]"

and remove them from the 'unwise' set:

      unwise      = "{" | "}" | "|" | "\" | "^" | "`"

4. Security Considerations

The use of this approach to represent literal IPv6 addresses in URL's does not introduce any known new security concerns.

5. IANA Considerations

None.

6. Authors' Addresses

Robert M. Hinden
Nokia
313 Fairchild Drive
Mountain View, CA 94043
USA

   Phone: +1 650 625 2004
   EMail: hinden@iprg.nokia.com
   Web: http://www.iprg.nokia.com/~hinden

Brian E. Carpenter
IBM
iCAIR, Suite 150
1890 Maple Avenue
Evanston IL 60201
USA

EMail:

          brian@icair.org

Larry Masinter
AT&T Labs
75 Willow Road
Menlo Park, CA 94025

   EMail: LMM@acm.org
   Web: http://larry.masinter.net

7. References

   [ARCH]     Hinden, R. and  S. Deering, "IP Version 6 Addressing
   
              Architecture", RFC 2373, July 1998.
   
   [STD-PROC] Bradner, S., The Internet Standards Process -- Revision 3,
              BCP 9, RFC 2026, October 1996.
   
   [URL]      Fielding, R., Masinter, L. and T. Berners-Lee, "Uniform
              Resource Identifiers: Generic Syntax", RFC 2396, August
              1998.

8. Full Copyright Statement

Copyright © The Internet Society (1999). All Rights Reserved.

This document and translations of it may be copied and furnished to others, and derivative works that comment on or otherwise explain it or assist in its implementation may be prepared, copied, published and distributed, in whole or in part, without restriction of any kind, provided that the above copyright notice and this paragraph are included on all such copies and derivative works. However, this document itself may not be modified in any way, such as by removing the copyright notice or references to the Internet Society or other Internet organizations, except as needed for the purpose of developing Internet standards in which case the procedures for copyrights defined in the Internet Standards process must be followed, or as required to translate it into languages other than English.

The limited permissions granted above are perpetual and will not be revoked by the Internet Society or its successors or assigns.

This document and the information contained herein is provided on an "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIMS 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.

Acknowledgement

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