INTERNET-DRAFT                                          K. Luehrs
Dynamic Host Control Working Group                      CableLabs
Expires March 2003                                      J. Bevilacqua
                                                        YAS Corporation
                                                        September 2002


                KDC Server Address Sub-option
         < draft-ietf-dhc-suboptions-kdc-serveraddress-00.txt>

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
   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 (2002). All Rights Reserved.

Abstract

   This document defines a new sub-option for the CableLabs Client
   Configuration (CCC) DHCP option code for conveying the network
   address of the Key Distribution Center (KDC) server.

1.  Introduction

   The need for a CCC DHCP Option code is described in [1]. The CCC
   DHCP option code will be used to address specific needs of CableLabs
   client devices during their configuration processes. This document
   proposes a sub-option for the CCC DHCP option.



Luehrs and Bevilacqua      Expires March 2003         [Page 1]


Internet Draft    KDC Server Address Sub-option       September 2002


   Configuration of a class of CableLabs client devices described in
   [2] requires a DHCP sub-option to provide the client with the
   address of the cable operator's KDC server.  This document proposes
   an additional sub-option for use with CableLabs client devices. The
   sub-option encodes an identifier of the network address for the Key
   Distribution Center server with which the CableLabs client device
   must exchange security information.

   CableLabs plans to assign sub-option code ranges according to
   CableLabs projects. The range (51 - 100) is assigned to the
   CableHome project. Use of the initial value of this range is
   specified in [2].

   The key words "MUST", "MUST NOT", "SHOULD", "SHOULD NOT" and "MAY"
   in this document are to be interpreted as described in RFC 2119 [3].


2.  Key Distribution Center IP Address Sub-option

   The CableHome 1.0 specification [2] specifies the Key Distribution
   Center network address encoding as a sub-option of the CCC DHCP
   Option code. This field is used to inform the client device of the
   network address of the Key Distribution Center server.

   The encoding of sub-option 51 will adhere to the format of an IPv4
   address using the default port. The sub-option length MUST be 4. The
   length octet MUST be followed by 4 octets of IPv4 address.

   The KDC Server sub-option is coded as follows:

            SubOpt  Len        Address
           +------+-----+------+------+------+------+
           |  51  |  4  |  a1  |  a2  |  a3  |  a4  |
           +------+-----+------+------+------+------+


3.  Security Considerations

   This document relies upon the DHCP protocol [4] for authentication
   and security, i.e., it does not provide security in excess of what
   DHCP is (or will be) providing. It does not expose any security
   threats beyond what is currently exposed by other DHCP options.


4.  IANA Considerations

   IANA has assigned a value of 51 for the CableLabs Client
   Configuration (CCC) sub-option code described in [1] and referred
   to in this document.



Luehrs and Bevilacqua      Expires March 2003         [Page 2]


Internet Draft    KDC Server Address Sub-option       September 2002


5.  Normative References


   [1] "DHCP Option for CableLabs Client Configuration  draft-ietf-dhc-
        packetcable-03", IETF, July 2002.

   [2] "CableHome 1.0 Specification SP-CH1.0-I02-020920", CableLabs,
      September 2002, http://www.cablelabs.com/cablehome/specifications

   [3] Bradner, S., "Key words for use in RFCs to Indicate Requirement
       Levels", BCP 14, RFC 2119, March 1997.

   [4] Droms, R., "Dynamic Host Configuration Protocol", RFC 2131, March
       1997.

6.  Authors' Addresses

        Kevin Luehrs
        CableLabs
        400 Centennial Parkway
        Louisville, CO 80027
        Phone:  (303) 661-9100
        EMail:  k.luehrs@cablelabs.com

      John Bevilacqua
      YAS Corporation
      300 Brickstone Square
      Andover, MA 01810
      Phone: (978) 749-9999
      EMail: john@yas.com

7.  Full Copyright Statement

   Copyright (C) The Internet Society (2002). 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 develop-
   ing 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.


Luehrs and Bevilacqua      Expires March 2003            [Page 3]


Internet Draft    KDC Server Address Sub-option       September 2002

   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.















































Luehrs and Bevilacqua      Expires March 2003         [Page 4]