269 lines
6.3 KiB
Plaintext
269 lines
6.3 KiB
Plaintext
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Network Working Group S. Thomson
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Request for Comments: 1886 Bellcore
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Category: Standards Track C. Huitema
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INRIA
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December 1995
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DNS Extensions to support IP version 6
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Status of this Memo
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This document specifies an Internet standards track protocol for the
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Internet community, and requests discussion and suggestions for
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improvements. Please refer to the current edition of the "Internet
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Official Protocol Standards" (STD 1) for the standardization state
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and status of this protocol. Distribution of this memo is unlimited.
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Abstract
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This document defines the changes that need to be made to the Domain
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Name System to support hosts running IP version 6 (IPv6). The
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changes include a new resource record type to store an IPv6 address,
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a new domain to support lookups based on an IPv6 address, and updated
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definitions of existing query types that return Internet addresses as
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part of additional section processing. The extensions are designed
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to be compatible with existing applications and, in particular, DNS
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implementations themselves.
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Thompson & Huitema Standards Track [Page 1]
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RFC 1886 IPv6 DNS Extensions December 1995
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1. INTRODUCTION
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Current support for the storage of Internet addresses in the Domain
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Name System (DNS)[1,2] cannot easily be extended to support IPv6
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addresses[3] since applications assume that address queries return
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32-bit IPv4 addresses only.
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To support the storage of IPv6 addresses we define the following
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extensions:
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o A new resource record type is defined to map a domain name to an
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IPv6 address.
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o A new domain is defined to support lookups based on address.
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o Existing queries that perform additional section processing to
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locate IPv4 addresses are redefined to perform additional
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section processing on both IPv4 and IPv6 addresses.
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The changes are designed to be compatible with existing software. The
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existing support for IPv4 addresses is retained. Transition issues
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related to the co-existence of both IPv4 and IPv6 addresses in DNS
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are discussed in [4].
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2. NEW RESOURCE RECORD DEFINITION AND DOMAIN
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A new record type is defined to store a host's IPv6 address. A host
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that has more than one IPv6 address must have more than one such
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record.
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2.1 AAAA record type
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The AAAA resource record type is a new record specific to the
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Internet class that stores a single IPv6 address.
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The value of the type is 28 (decimal).
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2.2 AAAA data format
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A 128 bit IPv6 address is encoded in the data portion of an AAAA
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resource record in network byte order (high-order byte first).
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Thompson & Huitema Standards Track [Page 2]
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RFC 1886 IPv6 DNS Extensions December 1995
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2.3 AAAA query
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An AAAA query for a specified domain name in the Internet class
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returns all associated AAAA resource records in the answer section of
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a response.
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A type AAAA query does not perform additional section processing.
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2.4 Textual format of AAAA records
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The textual representation of the data portion of the AAAA resource
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record used in a master database file is the textual representation
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of a IPv6 address as defined in [3].
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2.5 IP6.INT Domain
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A special domain is defined to look up a record given an address. The
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intent of this domain is to provide a way of mapping an IPv6 address
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to a host name, although it may be used for other purposes as well.
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The domain is rooted at IP6.INT.
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An IPv6 address is represented as a name in the IP6.INT domain by a
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sequence of nibbles separated by dots with the suffix ".IP6.INT". The
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sequence of nibbles is encoded in reverse order, i.e. the low-order
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nibble is encoded first, followed by the next low-order nibble and so
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on. Each nibble is represented by a hexadecimal digit. For example,
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the inverse lookup domain name corresponding to the address
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4321:0:1:2:3:4:567:89ab
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would be
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b.a.9.8.7.6.5.0.4.0.0.0.3.0.0.0.2.0.0.0.1.0.0.0.0.0.0.0.1.2.3.4.IP6.INT.
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3. MODIFICATIONS TO EXISTING QUERY TYPES
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All existing query types that perform type A additional section
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processing, i.e. name server (NS), mail exchange (MX) and mailbox
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(MB) query types, must be redefined to perform both type A and type
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AAAA additional section processing. These new definitions mean that a
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name server must add any relevant IPv4 addresses and any relevant
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Thompson & Huitema Standards Track [Page 3]
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RFC 1886 IPv6 DNS Extensions December 1995
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IPv6 addresses available locally to the additional section of a
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response when processing any one of the above queries.
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4. SECURITY CONSIDERATIONS
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Security issues are not discussed in this memo.
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Thompson & Huitema Standards Track [Page 4]
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RFC 1886 IPv6 DNS Extensions December 1995
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5. REFERENCES
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[1] Mockapetris, P., "Domain Names - Concepts and Facilities", STD
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13, RFC 1034, USC/Information Sciences Institute, November 1987.
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[2] Mockapetris, P., "Domain Names - Implementation and Specifica-
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tion", STD 13, RFC 1035, USC/Information Sciences Institute,
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November 1987.
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[3] Hinden, R., and S. Deering, Editors, "IP Version 6 Addressing
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Architecture", RFC 1884, Ipsilon Networks, Xerox PARC, December
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1995.
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[4] Gilligan, R., and E. Nordmark, "Transition Mechanisms for IPv6
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Hosts and Routers", Work in Progress.
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Authors' Addresses
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Susan Thomson
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Bellcore
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MRE 2P343
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445 South Street
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Morristown, NJ 07960
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U.S.A.
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Phone: +1 201-829-4514
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EMail: set@thumper.bellcore.com
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Christian Huitema
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INRIA, Sophia-Antipolis
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2004 Route des Lucioles
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BP 109
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F-06561 Valbonne Cedex
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France
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Phone: +33 93 65 77 15
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EMail: Christian.Huitema@MIRSA.INRIA.FR
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Thompson & Huitema Standards Track [Page 5]
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