Anonymity Profiles for DHCP Clients
RFC 7844
Internet Engineering Task Force (IETF) C. Huitema
Request for Comments: 7844 Microsoft
Category: Standards Track T. Mrugalski
ISSN: 2070-1721 ISC
S. Krishnan
Ericsson
May 2016
Anonymity Profiles for DHCP Clients
Abstract
Some DHCP options carry unique identifiers. These identifiers can
enable device tracking even if the device administrator takes care of
randomizing other potential identifications like link-layer addresses
or IPv6 addresses. The anonymity profiles are designed for clients
that wish to remain anonymous to the visited network. The profiles
provide guidelines on the composition of DHCP or DHCPv6 messages,
designed to minimize disclosure of identifying information.
Status of This Memo
This is an Internet Standards Track document.
This document is a product of the Internet Engineering Task Force
(IETF). It represents the consensus of the IETF community. It has
received public review and has been approved for publication by the
Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 5741.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc7844.
Huitema, et al. Standards Track [Page 1]
RFC 7844 DHCP Anonymity Profiles May 2016
Copyright Notice
Copyright (c) 2016 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
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include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Huitema, et al. Standards Track [Page 2]
RFC 7844 DHCP Anonymity Profiles May 2016
Table of Contents
1. Introduction ....................................................4
1.1. Requirements ...............................................4
2. Application Domain ..............................................4
2.1. MAC Address Randomization Hypotheses .......................5
2.2. MAC Address Randomization and DHCP .........................6
2.3. Radio Fingerprinting .......................................6
2.4. Operating System Fingerprinting ............................7
2.5. No Anonymity Profile Identification ........................7
2.6. Using the Anonymity Profiles ...............................8
2.7. What about privacy for DHCP servers? .......................9
3. Anonymity Profile for DHCPv4 ....................................9
3.1. Avoiding Fingerprinting ...................................10
3.2. Client IP Address Field ...................................10
3.3. Requested IP Address Option ...............................11
3.4. Client Hardware Address Field .............................12
3.5. Client Identifier Option ..................................12
3.6. Parameter Request List Option .............................13
3.7. Host Name Option ..........................................13
3.8. Client FQDN Option ........................................14
3.9. UUID/GUID-Based Client Machine Identifier Option ..........15
3.10. User and Vendor Class DHCP Options .......................15
4. Anonymity Profile for DHCPv6 ...................................15
4.1. Avoiding Fingerprinting ...................................16
4.2. Do not send Confirm messages, unless really sure about
the location ..............................................17
4.3. Client Identifier DHCPv6 Option ...........................17
4.3.1. Anonymous Information-request ......................18
4.4. Server Identifier Option ..................................18
4.5. Address Assignment Options ................................18
4.5.1. Obtain Temporary Addresses .........................19
4.5.2. Prefix Delegation ..................................20
4.6. Option Request Option .....................................20
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