INTERNET-DRAFT                                          K. Luehrs
Dynamic Host Configuration Working Group                CableLabs
Expires June August 2003                                     R. Woundy
							AT&T Broadband
							Comcast Cable
							J. Bevilacqua
                                                        YAS Corporation
                                                        December 2002
                                                        February 2003

		KDC Server Address Sub-option
         <draft-ietf-dhc-suboptions-kdc-serveraddress-02.txt>
         <draft-ietf-dhc-suboptions-kdc-serveraddress-03.txt>

Status of this Memo

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

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Copyright Notice

   Copyright (C) The Internet Society (2002). (2003). All Rights Reserved.

Abstract

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

1.  Introduction

   The need for a

   A CCC DHCP Option code is described providing the KDC server address will be
   needed for CableHome-compliant residential gateways configured to
   use Kerberos for authentication as the first step in [1]. establishing
   a secure SNMPv3 link between the PS and the SNMP entity in the
   cable operator's data network.

   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, Woundy, & Bevilacqua        Expires June August 2003         [Page 1]   Internet Draft	  KDC Server Address Sub-option       December 2002       February 2003

   Configuration of a class of CableLabs client devices described in
   [2] requires will require a DHCP sub-option to provide the client with the
   network address of a KDC server in the cable operator's data
   network. The class of devices assumed in [2] is unlike the class
   of devices considered in [1], which perform a DNS lookup of the
   Kerberos Realm name to find the KDC server network address.

   This document proposes a sub-option of the CCC DHCP option
   code for use with CableLabs client devices. The proposed sub-option
   encodes an identifier for the network address of each of one or more
   Key Distribution Center servers with which the CableLabs client
   device exchanges security information.

   CableLabs plans to assign sub-option code ranges for the CCC option
   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 specifications will specify the Key Distribution
   Center network address encoding as a sub-option of the CCC DHCP
   Option code. This field is will be used to inform the client device of
   the network address of one or more Key Distribution Center servers.

   The encoding of the KDC Server Address sub-option will adhere to the
   format of an IPv4 address using the default port. address. The minimum length for this option is 4
   octets, and the length MUST always be a multiple of 4. If multiple
   KDC Servers are listed, they MUST be listed in decreasing order of
   priority. The format of the KDC Server Address sub-option of the CCC
   option code is as shown below:

    SubOpt  Len      Address 1               Address 2
   +------+-----+-----+-----+-----+-----+-----+-----+--
   |  51  TBD |  n  |  a1 |  a2 |  a3 |  a4 |  a1 |  a2 |  ...
   +------+-----+-----+-----+-----+-----+-----+-----+--

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

   The KDC Server Address sub-option described in this document is
   intended to be a sub-option of the CableLabs Client Configuration
   (CCC) option described in [1]. IANA will be is requested to assign and
   register a sub-option code 51 of the CCC option to the KDC Server
   Address sub-option.

5.  Normative References

   [1] "DHCP Option for CableLabs Client Configuration  draft-ietf-dhc-
        packetcable-05",
        packetcable-06", IETF, December 2002. February 2003.

   [2] "CableHome 1.0 Specification SP-CH1.0-I02-020920", SP-CH1.0-I03-030124", CableLabs,
      	September 2002,
      	January 2003, http://www.cablelabs.com/projects/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

	Richard Woundy
	AT&T Broadband
	Comcast Cable
	27 Industrial Drive
	Chelmsford, MA 01824
	Phone: (978) 244-4010
	EMail: rwoundy@broadband.att.com richard_woundy@cable.comcast.com

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

7.  Full Copyright Statement

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Acknowledgement

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