INTERNET-DRAFT                                      Andreas Gustafsson
draft-ietf-dnsind-dhcp-rr-00.txt                Internet Engines, Inc.
                                                          October 1999

                 A DNS RR for encoding DHCP information

Status of this Memo

   This document is an Internet-Draft and is in full conformance with
   all provisions of Section 10 of RFC2026.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF), its areas, and its working groups.  Note that
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Abstract

   This document describes a DNS RR for use by DHCP servers that need to
   store state information in the DNS.

Introduction

   A set of procedures to allow DHCP servers [RFC2131] to automatically
   update the DNS [RFC1034, RFC1035] is proposed in [DHCPDNS].

   A situation can arise where multiple DHCP clients request the same
   DNS name from their (possibly distinct) DHCP servers.  To resolve
   such conflicts, [DHCPDNS] proposes storing client identifiers in the
   DNS to unambiguously associate domain names with the DHCP clients
   "owning" them.  Early versions of [DHCPDNS] proposed using TXT
   records for encoding this information; the current version specifies
   the use of KEY records.

   In the interest of clarity, it would be preferable for this DHCP

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   information to use a distinct RR type rather than the existing KEY
   type.  A separate RR type can also improve efficiency by avoiding the
   unnecessary transmission of unrelated KEY records.

   This memo defines a distinct RR type for use by DHCP servers, the
   "DHCP" RR.

The DHCP RR

   The DHCP RR is defined with mnemonic DHCP and type code <TBD>.

DHCP RDATA format

   The RDATA section of a DHCP RR in transmission contains RDLENGTH
   bytes of binary data.  The format of this data and its interpretation
   by DHCP servers and clients, including the interpretation of multiple
   DHCP RRs at the same domain name, are TBD.  [This part of the
   specification should be driven by the needs of, and written in
   cooperation with, the DHCP Working Group and the authors of
   [DHCPDNS]].

   DNS software should consider the RDATA section to be opaque.  In DNS
   master files, the RDATA is represented as a hexadecimal string with
   an optional "0x" or "0X" prefix.  Periods (".") may be inserted
   anywhere after the "0x" for readability.  This format is identical to
   that of the NSAP RR [RFC1706].  The number of hexadecimal digits MUST
   be even.

Example

   A DHCP server allocating the IPv4 address 10.0.0.1 to a client
   "client.org.nil" might associate eight bytes of housekeeping
   information with the client as follows:

       client.org.nil. A    10.0.0.1
       client.org.nil. DHCP 01.23.45.67.89.ab.cd.ef

Security Considerations

   The DHCP record as such does not introduce any new security problems
   into the DNS.  However, care should be taken not to store sensitive
   information in DHCP records, since they are published along with
   other DNS data.  Note that even the hardware addresses of DHCP
   clients may be considered sensitive information.

IANA Considerations

   The IANA is requested to allocate an RR type number for the DHCP

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   record type from the regular RR type number range.

References

   [RFC1035] - Domain Names - Implementation and Specifications, P.
   Mockapetris, November 1987.

   [RFC1034] - Domain Names - Concepts and Facilities, P. Mockapetris,
   November 1987.

   [RFC1706] - DNS NSAP Resource Records, B. Manning, R. Colella,
   October 1994.

   [RFC2131] - Dynamic Host Configuration Protocol, R. Droms, March
   1997.

   [DHCPDNS] - draft-ietf-dhc-dhcp-dns-*.txt

Author's Address

   Andreas Gustafsson
   Internet Engines, Inc.
   950 Charter Street
   Redwood City, CA 94063
   USA

   Phone: +1 650 779 6004

   Email: gson@iengines.net

Full Copyright Statement

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

   This document and translations of it may be copied and furnished to
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   or assist in its implmentation may be prepared, copied, published and
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   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
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   copyrights defined in the Internet Standards process must be
   followed, or as required to translate it into languages other than
   English.

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   The limited permissions granted above are perpetual and will not be
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   This document and the information contained herein is provided on an
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