INTERNET-DRAFT K. Luehrs
Dynamic Host Configuration Working Group CableLabs
Expires August 2003 R. Woundy
Comcast Cable
J. Bevilacqua
YAS Corporation
February 2003
KDC Server Address Sub-option
<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.
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 (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
A CCC DHCP Option code providing the KDC server address will be
needed for CableHome-compliant residential gateways configured to
use Kerberos for authentication as the first step in 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 August 2003 [Page 1] Internet Draft KDC Server Address Sub-option February 2003
Configuration of a class of CableLabs client devices described in
[2] 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.
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
CableHome specifications will specify the Key Distribution
Center network address encoding as a sub-option of the CCC DHCP
Option code. This field 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. 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
+------+-----+-----+-----+-----+-----+-----+-----+--
| 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.
Luehrs, Woundy, & Bevilacqua Expires August 2003 [Page 2]
Internet Draft KDC Server Address Sub-option February 2003
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 is requested to assign and
register a sub-option code 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-06", IETF, February 2003.
[2] "CableHome 1.0 Specification SP-CH1.0-I03-030124", CableLabs,
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
Comcast Cable
27 Industrial Drive
Chelmsford, MA 01824
Phone: (978) 244-4010
EMail: richard_woundy@cable.comcast.com
John Bevilacqua
YAS Corporation
300 Brickstone Square
Andover, MA 01810
Phone: (978) 749-9999
EMail: john@yas.com
Luehrs, Woundy, & Bevilacqua Expires August 2003 [Page 3]
Internet Draft KDC Server Address Sub-option February 2003
7. Full Copyright Statement
Copyright (C) The Internet Society (2003). 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.
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
Funding for the RFC Editor function is currently provided by
the Internet Society.
Luehrs, Woundy, & Bevilacqua Expires August 2003 [Page 4]
