Network Working Group A. Cooper
Internet-Draft Cisco
Intended status: Informational F. Gont
Expires: April 13, 2015 Huawei Technologies
D. Thaler
Microsoft
October 10, 2014
Privacy Considerations for IPv6 Address Generation Mechanisms
draft-ietf-6man-ipv6-address-generation-privacy-02.txt
Abstract
This document discusses privacy and security considerations for
several IPv6 address generation mechanisms, both standardized and
non-standardized. It evaluates how different mechanisms mitigate
different threats and the trade-offs that implementors, developers,
and users face in choosing different addresses or address generation
mechanisms.
Status of This Memo
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This Internet-Draft will expire on April 13, 2015.
Copyright Notice
Copyright (c) 2014 IETF Trust and the persons identified as the
document authors. All rights reserved.
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to this document. Code Components extracted from this document must
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described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Weaknesses in IEEE-identifier-based IIDs . . . . . . . . . . 4
3.1. Correlation of activities over time . . . . . . . . . . . 5
3.2. Location tracking . . . . . . . . . . . . . . . . . . . . 6
3.3. Address scanning . . . . . . . . . . . . . . . . . . . . 6
3.4. Device-specific vulnerability exploitation . . . . . . . 6
4. Privacy and security properties of address generation
mechanisms . . . . . . . . . . . . . . . . . . . . . . . . . 7
4.1. IEEE-identifier-based IIDs . . . . . . . . . . . . . . . 9
4.2. Static, manually configured IIDs . . . . . . . . . . . . 10
4.3. Constant, semantically opaque IIDs . . . . . . . . . . . 10
4.4. Cryptographically generated IIDs . . . . . . . . . . . . 10
4.5. Stable, semantically opaque IIDs . . . . . . . . . . . . 10
4.6. Temporary IIDs . . . . . . . . . . . . . . . . . . . . . 11
4.7. DHCPv6 generation of IIDs . . . . . . . . . . . . . . . . 12
4.8. Transition/co-existence technologies . . . . . . . . . . 12
5. Miscellaneous Issues with IPv6 addressing . . . . . . . . . . 12
5.1. Geographic Location . . . . . . . . . . . . . . . . . . . 12
5.2. Network Operation . . . . . . . . . . . . . . . . . . . . 12
5.3. Compliance . . . . . . . . . . . . . . . . . . . . . . . 13
5.4. Intellectual Property Rights (IPRs) . . . . . . . . . . . 13
6. Security Considerations . . . . . . . . . . . . . . . . . . . 13
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13
8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 13
9. Informative References . . . . . . . . . . . . . . . . . . . 13
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 15
1. Introduction
IPv6 was designed to improve upon IPv4 in many respects, and
mechanisms for address assignment were one such area for improvement.
In addition to static address assignment and DHCP, stateless
autoconfiguration was developed as a less intensive, fate-shared
means of performing address assignment. With stateless
autoconfiguration, routers advertise on-link prefixes and hosts
generate their own interface identifiers (IIDs) to complete their
addresses. Over the years, many interface identifier generation
techniques have been defined, both standardized and non-standardized:
o Manual configuration
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* IPv4 address
* Service port
* Wordy
* Low-byte
o Stateless Address Auto-Cofiguration (SLAAC)
* IEEE 802 48-bit MAC or IEEE EUI-64 identifier
[RFC1972][RFC2464]
* Cryptographically generated [RFC3972]
* Temporary (also known as "privacy addresses") [RFC4941]
* Constant, semantically opaque (also known as random)
[Microsoft]
* Stable, semantically opaque [RFC7217]
o DHCPv6-based [RFC3315]
o Specified by transition/co-existence technologies
* IPv4 address and port [RFC4380]
Deriving the IID from a globally unique IEEE identifier [RFC2462] was
one of the earliest mechanisms developed. A number of privacy and
security issues related to the interface IDs derived from IEEE
identifiers were discovered after their standardization, and many of
the mechanisms developed later aimed to mitigate some or all of these
weaknesses. This document identifies four types of threats against
IEEE-identifier-based IIDs, and discusses how other existing
techniques for generating IIDs do or do not mitigate those threats.
2. Terminology
This section clarifies the terminology used throughout this document.
Public address:
An address that has been published in a directory or other public
location, such as the DNS, a SIP proxy, an application-specific
DHT, or a publicly available URI. A host's public addresses are
intended to be discoverable by third parties.
Stable address:
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An address that does not vary over time within the same network.
Note that [RFC4941] refers to these as "public" addresses, but
"stable" is used here for reasons explained in Section 4.
Temporary address:
An address that varies over time within the same network.
Constant IID:
An IPv6 Interface Identifier that is globally stable. That is,
the Interface ID will remain constant even if the node moves from
one network to another.
Stable IID:
An IPv6 Interface Identifier that is stable within some specified
context. For example, an Interface ID can be globally stable
(constant), or could be stable per network (meaning that the
Interface ID will remain unchanged as long as a the node stays on
the same network, but may change when the node moves from one
network to another).
Temporary IID:
An IPv6 Interface Identifier that varies over time.
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in
[RFC2119]. These words take their normative meanings only when they
are presented in ALL UPPERCASE.
3. Weaknesses in IEEE-identifier-based IIDs
There are a number of privacy and security implications that exist
for hosts that use IEEE-identifier-based IIDs. This section
discusses four generic attack types: correlation of activities over
time, location tracking, address scanning, and device-specific
vulnerability exploitation. The first three of these rely on the
attacker first gaining knowledge of the target host's IID. This can
be achieved by a number of different attackers: the operator of a
server to which the host connects, such as a web server or a peer-to-
peer server; an entity that connects to the same network as the
target (such as a conference network or any public network); or an
entity that is on-path to the destinations with which the host
communicates, such as a network operator.
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3.1. Correlation of activities over time
As with other identifiers, an IPv6 address can be used to correlate
the activities of a host for at least as long as the lifetime of the
address. The correlation made possible by IEEE-identifier-based IIDs
is of particular concern because MAC addresses are much more
permanent than, say, DHCP leases. MAC addresses tend to last roughly
the lifetime of a device's network interface, allowing correlation on
the order of years, compared to days for DHCP.
As [RFC4941] explains,
"[t]he use of a non-changing interface identifier to form
addresses is a specific instance of the more general case where a
constant identifier is reused over an extended period of time and
in multiple independent activities. Anytime the same identifier
is used in multiple contexts, it becomes possible for that
identifier to be used to correlate seemingly unrelated activity.
... The use of a constant identifier within an address is of
special concern because addresses are a fundamental requirement of
communication and cannot easily be hidden from eavesdroppers and
other parties. Even when higher layers encrypt their payloads,
addresses in packet headers appear in the clear."
IP addresses are just one example of information that can be used to
correlate activities over time. DNS names, cookies [RFC6265],
browser fingerprints [Panopticlick], and application-layer usernames
can all be used to link a host's activities together. Although IEEE-
identifier-based IIDs are likely to last at least as long or longer
than these other identifiers, IIDs generated in other ways may have
shorter or longer lifetimes than these identifiers depending on how
they are generated. Therefore, the extent to which a host's
activities can be correlated depends on whether the host uses
multiple identifiers together and the lifetimes of all of those
identifiers. Frequently refreshing an IPv6 address may not mitigate
correlation if an attacker has access to other longer lived
identifiers for a particular host. This is an important caveat to
keep in mind throughout the discussion of correlation in this
document. For further discussion of correlation, see Section 5.2.1
of [RFC6973].
As noted in [RFC4941], in some cases correlation is just as feasible
for a host using an IPv4 address as for a host using an IEEE
identifier to generate its IID in its IPv6 address. Hosts that use
static IPv4 addressing or who are consistently allocated the same
address via DHCPv4 can be tracked as described above. However, the
widespread use of both NAT and DHCPv4 implementations that assign the
same host a different address upon lease expiration mitigates this
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threat in the IPv4 case as compared to the IEEE identifier case in
IPv6.
3.2. Location tracking
Because the IPv6 address structure is divided between a topological
portion and an interface identifier portion, an interface identifier
that remains constant when a host connects to different networks (as
an IEEE-identifier-based IID does) provides a way for observers to
track the movements of that host. In a passive attack on a mobile
host, a server that receives connections from the same host over time
would be able to determine the host's movements as its prefix
changes.
Active attacks are also possible. An attacker that first learns the
host's interface identifier by being connected to the same network
segment, running a server that the host connects to, or being on-path
to the host's communications could subsequently probe other networks
for the presence of the same interface identifier by sending a probe
packet (ICMPv6 Echo Request, or any other probe packet). Even if the
host does not respond, the first hop router will usually respond with
an ICMP Address Unreachable when the host is not present, and be
silent when the host is present.
Location tracking based on IP address is generally not possible in
IPv4 since hosts get assigned wholly new addresses when they change
networks.
3.3. Address scanning
The structure of IEEE-based identifiers used for address generation
can be leveraged by an attacker to reduce the target search space
[I-D.ietf-opsec-ipv6-host-scanning]. The 24-bit Organizationally
Unique Identifier (OUI) of MAC addresses, together with the fixed
value (0xff, 0xfe) used to form a Modified EUI-64 Interface
Identifier, greatly help to reduce the search space, making it easier
for an attacker to scan for individual addresses using widely-known
popular OUIs. This erases much of the protection against address
scanning that the larger IPv6 address space was supposed to provide
as compared to IPv4.
3.4. Device-specific vulnerability exploitation
IPv6 addresses that embed IEEE identifiers leak information about the
device (Network Interface Card vendor, or even Operating System and/
or software type), which could be leveraged by an attacker with
knowledge of device/software-specific vulnerabilities to quickly find
possible targets. Attackers can exploit vulnerabilities in hosts
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whose IIDs they have previously obtained, or scan an address space to
find potential targets.
4. Privacy and security properties of address generation mechanisms
Analysis of the extent to which a particular host is protected
against the threats described in Section 3 depends on how each of a
host's addresses is generated and used. In some scenarios, a host
configures a single global address and uses it for all
communications. In other scenarios, a host configures multiple
addresses using different mechanisms and may use any or all of them.
[RFC3041] (later obsoleted by [RFC4941]) sought to address some of
the problems described in Section 3 by defining "temporary addresses"
for outbound connections. Temporary addresses are meant to
supplement the other addresses that a device might use, not to
replace them. They use IIDs that are randomly generated and change
daily by default. The idea was for temporary addresses to be used
for outgoing connections (e.g., web browsing) while maintaining the
ability to use a stable address when more address stability is
desired (e.g., in DNS advertisements).
[RFC3484] originally specified that stable addresses be used for
outbound connections unless an application explicitly prefers
temporary addresses. The default preference for stable addresses was
established to avoid applications potentially failing due to the
short lifetime of temporary addresses or the possibility of a reverse
look-up failure or error. However, [RFC3484] allowed that
"implementations for which privacy considerations outweigh these
application compatibility concerns MAY reverse the sense of this
rule" and instead prefer by default temporary addresses rather than
stable addresses. Indeed most implementations (notably including
Windows) chose to default to temporary addresses for outbound
connections since privacy was considered more important (and few
applications supported IPv6 at the time, so application compatibility
concerns were minimal). [RFC6724] then obsoleted [RFC3484] and
changed the default to match what implementations actually did.
The envisioned relationship in [RFC3484] between stability of an
address and its use in "public" can be misleading when conducting
privacy analysis. The stability of an address and the extent to
which it is linkable to some other public identifier are independent
of one another. For example, there is nothing that prevents a host
from publishing a temporary address in a public place, such as the
DNS. Publishing both a stable address and a temporary address in the
DNS or elsewhere where they can be linked together by a public
identifier allows the host's activities when using either address to
be correlated together.
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Moreover, because temporary addresses were designed to supplement
other addresses generated by a host, the host may still configure a
more stable address even if it only ever intentionally uses temporary
addresses (as source addresses) for communication to off-link
destinations. An attacker can probe for the stable address even if
it is never used as such a source address or advertised (e.g., in DNS
or SIP) outside the link.
This section compares the privacy and security properties of a
variety of IID generation mechanisms and their possible usage
scenarios, including scenarios in which a single mechanism is used to
generate all of a host's IIDs and those in which temporary addresses
are used together with addresses generated using a different IID
generation mechanism. The analysis of the exposure of each IID type
to correlation assumes that IPv6 prefixes are shared by a reasonably
large number of nodes. As [RFC4941] notes, if a very small number of
nodes (say, only one) use a particular prefix for an extended period
of time, the prefix itself can be used to correlate the host's
activities regardless of how the IID is generated. For example,
[RFC3314] recommends that prefixes be uniquely assigned to mobile
handsets where IPv6 is used within GPRS. In cases where this advice
is followed and prefixes persist for extended periods of time (or get
reassigned to the same handsets whenever those handsets reconnect to
the same network router), hosts' activities could be correlatable for
longer periods than the analysis below would suggest.
The table below provides a summary of the whole analysis.
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+--------------+-------------+----------+-------------+-------------+
| Mechanism(s) | Correlation | Location | Address | Device |
| | | tracking | scanning | exploits |
+--------------+-------------+----------+-------------+-------------+
| IEEE | For device | For | Possible | Possible |
| identifier | lifetime | device | | |
| | | lifetime | | |
| | | | | |
| Static | For address | For | Depends on | Depends on |
| manual | lifetime | address | generation | generation |
| | | lifetime | mechanism | mechanism |
| | | | | |
| Constant, | For address | For | No | No |
| semantically | lifetime | address | | |
| opaque | | lifetime | | |
| | | | | |
| CGA | For | No | No | No |
| | lifetime of | | | |
| | (modifier | | | |
| | block + | | | |
| | public key) | | | |
| | | | | |
| Stable, | Within | No | No | No |
| semantically | single | | | |
| opaque | network | | | |
| | | | | |
| Temporary | For temp | No | No | No |
| | address | | | |
| | lifetime | | | |
| | | | | |
| DHCPv6 | For lease | No | Depends on | No |
| | lifetime | | generation | |
| | | | mechanism | |
+--------------+-------------+----------+-------------+-------------+
Table 1: Privacy and security properties of IID generation mechanisms
4.1. IEEE-identifier-based IIDs
As discussed in Section 3, addresses that use IIDs based on IEEE
identifiers are vulnerable to all four threats. They allow
correlation and location tracking for the lifetime of the device
since IEEE identifiers last that long and their structure makes
address scanning and device exploits possible.
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4.2. Static, manually configured IIDs
Because static, manually configured IIDs are stable, both correlation
and location tracking are possible for the life of the address.
The extent to which location tracking can be successfully performed
depends, to a some extent, on the uniqueness of the employed
Interface ID. For example, one would expect "low byte" Interface IDs
to be more widely reused than, for example, Interface IDs where the
whole 64-bits follow some pattern that is unique to a specific
organization. Widely reused Interface IDs will typically lead to
false positives when performing location tracking.
Whether manually configured addresses are vulnerable to address
scanning and device exploits depends on the specifics of how the IIDs
are generated.
4.3. Constant, semantically opaque IIDs
Although a mechanism to generate a constant, semantically opaque IID
has not been standardized, it has been in wide use for many years on
at least one platform (Windows). Windows uses the [RFC4941] random
generation mechanism in lieu of generating an IEEE-identifier-based
IID. This mitigates the device-specific exploitation and address
scanning attacks, but still allows correlation and location tracking
because the IID is constant across networks and time.
4.4. Cryptographically generated IIDs
Cryptographically generated addresses (CGAs) [RFC3972] bind a hash of
the host's public key to an IPv6 address in the SEcure Neighbor
Discovery (SEND) [RFC3971] protocol. CGAs may be regenerated for
each subnet prefix, but this is not required given that they are
computationally expensive to generate. A host using a CGA can be
correlated for as long as the lifetime of the combination of the
public key and the chosen modifier block, since it is possible to
rotate modifier blocks without generating new public keys. Because
the cryptographic hash of the host's public key uses the subnet
prefix as an input, even if the host does not generate a new public
key or modifier block when it moves to a different network, its
location cannot be tracked via the IID. CGAs do not allow device-
specific exploitation or address scanning attacks.
4.5. Stable, semantically opaque IIDs
[RFC7217] specifies a mechanism that generates a unique random IID
for each network. A host that stays connected to the same network
could therefore be tracked at length, whereas a mobile host's
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activities could only be correlated for the duration of each network
connection. Location tracking is not possible with these addresses.
They also do not allow device-specific exploitation or address
scanning attacks.
4.6. Temporary IIDs
A host that uses only a temporary address mitigates all four threats.
Its activities may only be correlated for the lifetime a single
temporary address.
A host that configures both an IEEE-identifier-based IID and
temporary addresses makes the host vulnerable to the same attacks as
if temporary addresses were not in use, although the viability of
some of them depends on how the host uses each address. An attacker
can correlate all of the host's activities for which it uses its
IEEE-identifier-based IID. Once an attacker has obtained the IEEE-
identifier-based IID, location tracking becomes possible on other
networks even if the host only makes use of temporary addresses on
those other networks; the attacker can actively probe the other
networks for the presence of the IEEE-identifier-based IID. Device-
specific vulnerabilities can still be exploited. Address scanning is
also still possible because the IEEE-identifier-based address can be
probed.
If the host instead generates a constant, semantically opaque IID to
use in a stable address for server-like connections together with
temporary addresses for outbound connections (as is the default in
Windows), it sees some improvements over the previous scenario. The
address scanning and device-specific exploitation attacks are no
longer possible because the OUI is no longer embedded in any of the
host's addresses. However, correlation of some activities across
time and location tracking are both still possible because the
semantically opaque IID is constant. And once an attacker has
obtained the host's semantically opaque IID, location tracking is
possible on any network by probing for that IID, even if the host
only uses temporary addresses on those networks. However, if the
host generates but never uses a constant, semantically opaque IID, it
mitigates all four threats.
When used together with temporary addresses, the stable, semantically
opaque IID generation mechanism [RFC7217] improves upon the previous
scenario by limiting the potential for correlation to the lifetime of
the stable address (which may still be lengthy for hosts that are not
mobile) and by eliminating the possibility for location tracking
(since a different IID is generated for each subnet prefix). As in
the previous scenario, a host that configures but does not use a
stable, semantically opaque address mitigates all four threats.
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4.7. DHCPv6 generation of IIDs
The security/privacy implications of DHCPv6-based addresses will
typically depend on the specific DHCPv6 server software being
employed. We note that recent releases of most popular DHCPv6 server
software typically lease random addresses with a similar lease time
as that of IPv4. Thus, these addresses can be considered to be
"stable, semantically opaque."
On the other hand, some DHCPv6 software leases sequential addresses
(typically low-byte addresses). These addresses can be considered to
be stable addresses. The drawback of this address generation scheme
compared to "stable, semantically opaque" addresses is that, since
they follow specific patterns, they enable IPv6 address scans.
4.8. Transition/co-existence technologies
Addresses specified based on transition/co-existence technologies
that embed an IPv4 address within an IPv6 address are not included in
Table 1 because their privacy and security properties are inherited
from the embedded address. For example, Teredo [RFC4380] specifies a
means to generate an IPv6 address from the underlying IPv4 address
and port, leaving many other bits set to zero. This makes it
relatively easy for an attacker to scan for IPv6 addresses by
guessing the Teredo client's IPv4 address and port (which for many
NATs is not randomized). For this reason, popular implementations
(e.g., Windows), began deviating from the standard by including 12
random bits in place of zero bits. This modification was later
standardized in [RFC5991].
5. Miscellaneous Issues with IPv6 addressing
5.1. Geographic Location
Since IPv6 subnets have unique prefixes, they reveal some information
about the location of the subnet, just as IPv4 addresses do. Hiding
this information is one motivation for using NAT in IPv6 (see RFC
5902 section 2.4).
5.2. Network Operation
It is generally agreed that IPv6 addresses that vary over time in a
specific network tend to increase the complexity of event logging,
trouble-shooting, enforcement of access controls and quality of
service, etc. As a result, some organizations disable the use of
temporary addresses [RFC4941] even at the expense of reduced privacy
[Broersma].
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5.3. Compliance
Some IPv6 compliance testing suites required (and might still
require) implementations to support MAC-derived suffixes in order to
be approved as compliant. This document recommends that compliance
testing suites be relaxed to allow other forms of address generation
that are more amenable to privacy.
5.4. Intellectual Property Rights (IPRs)
Some IPv6 addressing techniques might be covered by Intellectual
Property rights, which might limit their implementation in different
Operating Systems. [CGA-IPR] and [KAME-CGA] discuss the IPRs on
CGAs.
6. Security Considerations
This whole document concerns the privacy and security properties of
different IPv6 address generation mechanisms.
7. IANA Considerations
This document does not require actions by IANA.
8. Acknowledgements
The authors would like to thank Bernard Aboba, Tim Chown, Rich
Draves, Robert Moskowitz, Erik Nordmark, and James Woodyatt for
providing valuable comments on earlier versions of this document.
9. Informative References
[Broersma]
Broersma, R., "IPv6 Everywhere: Living with a Fully
IPv6-enabled environment", Australian IPv6 Summit 2010,
Melbourne, VIC Australia, October 2010, October 2010,
<http://www.ipv6.org.au/10ipv6summit/talks/
Ron_Broersma.pdf>.
[CGA-IPR] IETF, "Intellectual Property Rights on RFC 3972", 2005.
[I-D.ietf-opsec-ipv6-host-scanning]
Gont, F. and T. Chown, "Network Reconnaissance in IPv6
Networks", draft-ietf-opsec-ipv6-host-scanning-04 (work in
progress), June 2014.
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[KAME-CGA]
KAME, "The KAME IPR policy and concerns of some
technologies which have IPR claims", 2005.
[Microsoft]
Microsoft, "IPv6 interface identifiers", 2013.
[Panopticlick]
Electronic Frontier Foundation, "Panopticlick", 2011.
[RFC1972] Crawford, M., "A Method for the Transmission of IPv6
Packets over Ethernet Networks", RFC 1972, August 1996.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2462] Thomson, S. and T. Narten, "IPv6 Stateless Address
Autoconfiguration", RFC 2462, December 1998.
[RFC2464] Crawford, M., "Transmission of IPv6 Packets over Ethernet
Networks", RFC 2464, December 1998.
[RFC3041] Narten, T. and R. Draves, "Privacy Extensions for
Stateless Address Autoconfiguration in IPv6", RFC 3041,
January 2001.
[RFC3314] Wasserman, M., "Recommendations for IPv6 in Third
Generation Partnership Project (3GPP) Standards", RFC
3314, September 2002.
[RFC3315] Droms, R., Bound, J., Volz, B., Lemon, T., Perkins, C.,
and M. Carney, "Dynamic Host Configuration Protocol for
IPv6 (DHCPv6)", RFC 3315, July 2003.
[RFC3484] Draves, R., "Default Address Selection for Internet
Protocol version 6 (IPv6)", RFC 3484, February 2003.
[RFC3971] Arkko, J., Kempf, J., Zill, B., and P. Nikander, "SEcure
Neighbor Discovery (SEND)", RFC 3971, March 2005.
[RFC3972] Aura, T., "Cryptographically Generated Addresses (CGA)",
RFC 3972, March 2005.
[RFC4380] Huitema, C., "Teredo: Tunneling IPv6 over UDP through
Network Address Translations (NATs)", RFC 4380, February
2006.
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[RFC4941] Narten, T., Draves, R., and S. Krishnan, "Privacy
Extensions for Stateless Address Autoconfiguration in
IPv6", RFC 4941, September 2007.
[RFC5991] Thaler, D., Krishnan, S., and J. Hoagland, "Teredo
Security Updates", RFC 5991, September 2010.
[RFC6265] Barth, A., "HTTP State Management Mechanism", RFC 6265,
April 2011.
[RFC6724] Thaler, D., Draves, R., Matsumoto, A., and T. Chown,
"Default Address Selection for Internet Protocol Version 6
(IPv6)", RFC 6724, September 2012.
[RFC6973] Cooper, A., Tschofenig, H., Aboba, B., Peterson, J.,
Morris, J., Hansen, M., and R. Smith, "Privacy
Considerations for Internet Protocols", RFC 6973, July
2013.
[RFC7217] Gont, F., "A Method for Generating Semantically Opaque
Interface Identifiers with IPv6 Stateless Address
Autoconfiguration (SLAAC)", RFC 7217, April 2014.
Authors' Addresses
Alissa Cooper
Cisco
707 Tasman Drive
Milpitas, CA 95035
US
Phone: +1-408-902-3950
Email: alcoop@cisco.com
URI: https://www.cisco.com/
Fernando Gont
Huawei Technologies
Evaristo Carriego 2644
Haedo, Provincia de Buenos Aires 1706
Argentina
Phone: +54 11 4650 8472
Email: fgont@si6networks.com
URI: http://www.si6networks.com
Cooper, et al. Expires April 13, 2015 [Page 15]
Internet-Draft IPv6 Address Generation Privacy October 2014
Dave Thaler
Microsoft
Microsoft Corporation
One Microsoft Way
Redmond, WA 98052
Phone: +1 425 703 8835
Email: dthaler@microsoft.com
Cooper, et al. Expires April 13, 2015 [Page 16]
