IPv6 maintenance Working Group (6man) F. Gont
Internet-Draft SI6 Networks / UTN-FRH
Updates: 2464, 2467, 2470, 2491, 2492, A. Cooper
2497, 2590, 3146, 3572, 4291, Cisco
4338, 4391, 4944, 5072, 5121 D. Thaler
(if approved) Microsoft
Intended status: Standards Track W. Liu
Expires: July 24, 2015 Huawei Technologies
January 20, 2015
Recommendation on Stable IPv6 Interface Identifiers
draft-ietf-6man-default-iids-02
Abstract
The IPv6 addressing architecture defines Modified EUI-64 format
Interface Identifiers, and the existing IPv6 over various link-layers
specify how such identifiers are derived from the underlying link-
layer address (e.g., an IEEE LAN MAC address) when employing IPv6
Stateless Address Autoconfiguration (SLAAC). The security and
privacy implications of embedding link-layer addresses in the
Interface Identifier have been known and understood for some time
now, and some popular IPv6 implementations have already deviated from
such schemes to mitigate these issues. This document changes the
recommended default Interface Identifier generation scheme to that
specified in RFC7217, and recommends against embedding link-layer
addresses in IPv6 Interface Identifiers. It formally updates
RFC2464, RFC2467, RFC2470, RFC2491, RFC2492, RFC2497, RFC2590,
RFC3146, RFC3572, RFC4291, RFC4338, RFC4391, RFC4944, RFC5072, and
RFC5121, which require IPv6 Interface Identifiers to be derived from
the underlying link-layer address.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/.
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."
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This Internet-Draft will expire on July 24, 2015.
Copyright Notice
Copyright (c) 2015 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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the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Generation of IPv6 Interface Identifiers . . . . . . . . . . 3
4. Future Work . . . . . . . . . . . . . . . . . . . . . . . . . 4
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4
6. Security Considerations . . . . . . . . . . . . . . . . . . . 4
7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 5
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 5
8.1. Normative References . . . . . . . . . . . . . . . . . . 5
8.2. Informative References . . . . . . . . . . . . . . . . . 7
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 7
1. Introduction
[RFC4862] specifies Stateless Address Autoconfiguration (SLAAC) for
IPv6 [RFC2460], which typically results in hosts configuring one or
more "stable" addresses composed of a network prefix advertised by a
local router, and an Interface Identifier (IID) [RFC4291] that
typically embeds a link-layer address (e.g., an IEEE LAN MAC
address).
In some network technologies and adaptation layers, the use of an
Interface-ID based on a link-layer address may offer some advantages.
For example, the IP-over-IEEE802.15.4 standard in [RFC6775] allows
for compression of IPv6 addresses when the Interface-ID is based on
the underlying link-layer address.
The security and privacy implications of embedding a link-layer
address in an IPv6 Interface ID have been known for some time now,
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and are discussed in great detail in
[I-D.ietf-6man-ipv6-address-generation-privacy]; they include:
o Network activity correlation
o Location tracking
o Address scanning
o Device-specific vulnerability exploitation
Some popular IPv6 implementations have already deviated from the
traditional stable IID generation scheme to mitigate the
aforementioned security and privacy implications [Microsoft].
As a result of the aforementioned issues, this document recommends
the implementation of an alternative scheme ([RFC7217]) as the
default stable Interface-ID generation scheme, such that the
aforementioned issues are mitigated.
NOTE: [RFC4291] defines the "Modified EUI-64 format" for Interface
identifiers. Appendix A of [RFC4291] then describes how to transform
an IEEE EUI-64 identifier, or an IEEE 802 48-bit MAC address from
which an EUI-64 identifier is derived, into an interface identifier
in the Modified EUI-64 format.
2. Terminology
Stable address:
An address that does not vary over time within the same network
(as defined in [I-D.ietf-6man-ipv6-address-generation-privacy].
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119].
3. Generation of IPv6 Interface Identifiers
Nodes SHOULD implement and employ [RFC7217] as the default scheme for
generating stable IPv6 addresses with SLAAC. Link layers MUST define
a mechanism that provides that mitigates the security and privacy
implications discussed in Section 1. A link layer MAY also define a
mechanism that is more efficient and does not address the security
and privacy considerations discussed in Section 1. The choice of
whether to enable privacy or not SHOULD be configurable in such a
case.
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Nodes SHOULD NOT employ IPv6 address generation schemes that embed
the underlying link-layer address in the Interface Identifier. In
particular, this document RECOMMENDS that nodes do not generate
Interface Identifiers with the schemes specified in [RFC2464],
[RFC2467], [RFC2470], [RFC2491], [RFC2492], [RFC2497], [RFC2590],
[RFC3146], [RFC3572], [RFC4338], [RFC4391], [RFC4944], [RFC5121], and
[RFC5072], and updates these documents with this recommendation.
It is RECOMMENDED by this document that future specifications do not
specify IPv6 address generation schemes that embed the underlying
link-layer address in the Interface Identifier. Future
specifications MAY use a an IID based on a node's link-layer address
if design and engineering considerations warrant.
4. Future Work
At the time of this writing, the mechanisms specified in the
following documents are not compatible with the recommendations in
this document:
o RFC 6282 [RFC6282]
o RFC 4944 [RFC4944]
o RFC 6755 [RFC6775]
Future revisions or updates of these documents should take the issues
of privacy and security mentioned in Section 1 1 and explain any
design and engineering considerations that lead to the use of IIDs
based on a node's link-layer address.
5. IANA Considerations
There are no IANA registries within this document. The RFC-Editor
can remove this section before publication of this document as an
RFC.
6. Security Considerations
This document recommends [RFC7217] as the default scheme for
generating IPv6 stable addresses with SLAAC, such that the security
and privacy issues of Interface IDs that embed link-layer addresses
are mitigated.
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7. Acknowledgements
The authors would like to thank Erik Nordmark and Ray Hunter for
providing a detailed review of this document.
The authors would like to thank (in alphabetical order) Fred Baker,
Carsten Bormann, Scott Brim, Brian Carpenter, Samita Chakrabarti, Tim
Chown, Lorenzo Colitti, Jean-Michel Combes, Greg Daley, Esko Dijk,
Ralph Droms, David Farmer, Brian Haberman, Ulrich Herberg, Bob
Hinden, Jahangir Hossain, Jonathan Hui, Ray Hunter, Sheng Jiang,
Roger Jorgensen, Dan Luedtke, Kerry Lynn, George Mitchel, Erik
Nordmark, Simon Perreault, Tom Petch, Alexandru Petrescu, Michael
Richardson, Arturo Servin, Mark Smith, Tom Taylor, Ole Troan, Tina
Tsou, Glen Turner, and Randy Turner, for providing valuable comments
on earlier versions of this document.
8. References
8.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2460] Deering, S. and R. Hinden, "Internet Protocol, Version 6
(IPv6) Specification", RFC 2460, December 1998.
[RFC2464] Crawford, M., "Transmission of IPv6 Packets over Ethernet
Networks", RFC 2464, December 1998.
[RFC2467] Crawford, M., "Transmission of IPv6 Packets over FDDI
Networks", RFC 2467, December 1998.
[RFC2470] Crawford, M., Narten, T., and S. Thomas, "Transmission of
IPv6 Packets over Token Ring Networks", RFC 2470, December
1998.
[RFC2492] Armitage, G., Schulter, P., and M. Jork, "IPv6 over ATM
Networks", RFC 2492, January 1999.
[RFC4291] Hinden, R. and S. Deering, "IP Version 6 Addressing
Architecture", RFC 4291, February 2006.
[RFC4862] Thomson, S., Narten, T., and T. Jinmei, "IPv6 Stateless
Address Autoconfiguration", RFC 4862, September 2007.
[RFC7217] Gont, F., "A Method for Generating Semantically Opaque
Interface Identifiers with IPv6 Stateless Address
Autoconfiguration (SLAAC)", RFC 7217, April 2014.
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[RFC2491] Armitage, G., Schulter, P., Jork, M., and G. Harter, "IPv6
over Non-Broadcast Multiple Access (NBMA) networks", RFC
2491, January 1999.
[RFC2497] Souvatzis, I., "Transmission of IPv6 Packets over ARCnet
Networks", RFC 2497, January 1999.
[RFC2590] Conta, A., Malis, A., and M. Mueller, "Transmission of
IPv6 Packets over Frame Relay Networks Specification", RFC
2590, May 1999.
[RFC3146] Fujisawa, K. and A. Onoe, "Transmission of IPv6 Packets
over IEEE 1394 Networks", RFC 3146, October 2001.
[RFC3572] Ogura, T., Maruyama, M., and T. Yoshida, "Internet
Protocol Version 6 over MAPOS (Multiple Access Protocol
Over SONET/SDH)", RFC 3572, July 2003.
[RFC4338] DeSanti, C., Carlson, C., and R. Nixon, "Transmission of
IPv6, IPv4, and Address Resolution Protocol (ARP) Packets
over Fibre Channel", RFC 4338, January 2006.
[RFC4391] Chu, J. and V. Kashyap, "Transmission of IP over
InfiniBand (IPoIB)", RFC 4391, April 2006.
[RFC4944] Montenegro, G., Kushalnagar, N., Hui, J., and D. Culler,
"Transmission of IPv6 Packets over IEEE 802.15.4
Networks", RFC 4944, September 2007.
[RFC5121] Patil, B., Xia, F., Sarikaya, B., Choi, JH., and S.
Madanapalli, "Transmission of IPv6 via the IPv6
Convergence Sublayer over IEEE 802.16 Networks", RFC 5121,
February 2008.
[RFC5072] Varada, S., Haskins, D., and E. Allen, "IP Version 6 over
PPP", RFC 5072, September 2007.
[RFC6282] Hui, J. and P. Thubert, "Compression Format for IPv6
Datagrams over IEEE 802.15.4-Based Networks", RFC 6282,
September 2011.
[RFC6775] Shelby, Z., Chakrabarti, S., Nordmark, E., and C. Bormann,
"Neighbor Discovery Optimization for IPv6 over Low-Power
Wireless Personal Area Networks (6LoWPANs)", RFC 6775,
November 2012.
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8.2. Informative References
[I-D.ietf-6man-ipv6-address-generation-privacy]
Cooper, A., Gont, F., and D. Thaler, "Privacy
Considerations for IPv6 Address Generation Mechanisms",
draft-ietf-6man-ipv6-address-generation-privacy-03 (work
in progress), January 2015.
[Microsoft]
Davies, J., "Understanding IPv6, 3rd. ed", page 83,
Microsoft Press, 2012, <http://it-ebooks.info/book/1022/>.
Authors' Addresses
Fernando Gont
SI6 Networks / UTN-FRH
Evaristo Carriego 2644
Haedo, Provincia de Buenos Aires 1706
Argentina
Phone: +54 11 4650 8472
Email: fgont@si6networks.com
URI: http://www.si6networks.com
Alissa Cooper
Cisco
707 Tasman Drive
Milpitas, CA 95035
US
Phone: +1-408-902-3950
Email: alcoop@cisco.com
URI: https://www.cisco.com/
Dave Thaler
Microsoft
Microsoft Corporation
One Microsoft Way
Redmond, WA 98052
Phone: +1 425 703 8835
Email: dthaler@microsoft.com
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Will Liu
Huawei Technologies
Bantian, Longgang District
Shenzhen 518129
P.R. China
Email: liushucheng@huawei.com
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