A DNS Resource Record (RR) for Encoding Dynamic Host Configuration Protocol (DHCP) Information (DHCID RR)
RFC 4701
Document | Type |
RFC - Proposed Standard
(October 2006; Errata)
Updated by RFC 5494
|
|
---|---|---|---|
Authors | Andreas Gustafsson , Ted Lemon , Mark Stapp | ||
Last updated | 2015-10-14 | ||
Stream | Internent Engineering Task Force (IETF) | ||
Formats | plain text html pdf htmlized (tools) htmlized bibtex | ||
Stream | WG state | (None) | |
Document shepherd | No shepherd assigned | ||
IESG | IESG state | RFC 4701 (Proposed Standard) | |
Action Holders |
(None)
|
||
Consensus Boilerplate | Unknown | ||
Telechat date | |||
Responsible AD | Margaret Cullen | ||
Send notices to | <okolkman@ripe.net> |
Network Working Group M. Stapp Request for Comments: 4701 Cisco Systems, Inc. Category: Standards Track T. Lemon Nominum, Inc. A. Gustafsson Araneus Information Systems Oy October 2006 A DNS Resource Record (RR) for Encoding Dynamic Host Configuration Protocol (DHCP) Information (DHCID RR) Status of This Memo This document specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "Internet Official Protocol Standards" (STD 1) for the standardization state and status of this protocol. Distribution of this memo is unlimited. Copyright Notice Copyright (C) The Internet Society (2006). Abstract It is possible for Dynamic Host Configuration Protocol (DHCP) clients to attempt to update the same DNS Fully Qualified Domain Name (FQDN) or to update a DNS FQDN that has been added to the DNS for another purpose as they obtain DHCP leases. Whether the DHCP server or the clients themselves perform the DNS updates, conflicts can arise. To resolve such conflicts, RFC 4703 proposes storing client identifiers in the DNS to unambiguously associate domain names with the DHCP clients to which they refer. This memo defines a distinct Resource Record (RR) type for this purpose for use by DHCP clients and servers: the "DHCID" RR. Stapp, et al. Standards Track [Page 1] RFC 4701 The DHCID RR October 2006 Table of Contents 1. Introduction ....................................................3 2. Terminology .....................................................3 3. The DHCID RR ....................................................3 3.1. DHCID RDATA Format .........................................3 3.2. DHCID Presentation Format ..................................4 3.3. The DHCID RR Identifier Type Codes .........................4 3.4. The DHCID RR Digest Type Code ..............................4 3.5. Computation of the RDATA ...................................5 3.5.1. Using the Client's DUID .............................5 3.5.2. Using the Client Identifier Option ..................6 3.5.3. Using the Client's htype and chaddr .................6 3.6. Examples ...................................................6 3.6.1. Example 1 ...........................................6 3.6.2. Example 2 ...........................................7 3.6.3. Example 3 ...........................................7 4. Use of the DHCID RR .............................................8 5. Updater Behavior ................................................8 6. Security Considerations .........................................8 7. IANA Considerations .............................................9 8. Acknowledgements ................................................9 9. References ......................................................9 9.1. Normative References .......................................9 9.2. Informative References ....................................10 Stapp, et al. Standards Track [Page 2] RFC 4701 The DHCID RR October 2006 1. Introduction A set of procedures to allow DHCP [7] [11] clients and servers to automatically update the DNS ([3], [4]) is proposed in [1]. Conflicts can arise if multiple DHCP clients wish to use the same DNS name or a DHCP client attempts to use a name added for another purpose. To resolve such conflicts, [1] proposes storing client identifiers in the DNS to unambiguously associate domain names with the DHCP clients using them. In the interest of clarity, it is preferable for this DHCP information to use a distinct RR type. This memo defines a distinct RR for this purpose for use by DHCP clients or servers: the "DHCID" RR. In order to obscure potentially sensitive client identifying information, the data stored is the result of a one-way SHA-256 hash computation. The hash includes information from the DHCP client's message as well as the domain name itself, so that the data stored in the DHCID RR will be dependent on both the client identification used in the DHCP protocol interaction and the domain name. This means that the DHCID RDATA will vary if a single client is associated over time with more than one name. This makes it difficult to 'track' aShow full document text