< draft-ietf-6man-ug-01.txt   draft-ietf-6man-ug-02.txt >
6MAN B. E. Carpenter 6MAN B. Carpenter
Internet-Draft Univ. of Auckland Internet-Draft Univ. of Auckland
Updates: 4291 (if approved) S. Jiang Updates: 4291 (if approved) S. Jiang
Intended status: Standards Track Huawei Technologies Co., Ltd Intended status: Standards Track Huawei Technologies Co., Ltd
Expires: November 26, 2013 May 25, 2013 Expires: February 07, 2014 August 06, 2013
Significance of IPv6 Interface Identifiers Significance of IPv6 Interface Identifiers
draft-ietf-6man-ug-01 draft-ietf-6man-ug-02
Abstract Abstract
The IPv6 addressing architecture includes a unicast interface The IPv6 addressing architecture includes a unicast interface
identifier that is used in the creation of many IPv6 addresses. identifier that is used in the creation of many IPv6 addresses.
Interface identifiers are formed by a variety of methods. This Interface identifiers are formed by a variety of methods. This
document clarifies that the bits in an interface identifier have no document clarifies that the bits in an interface identifier have no
generic meaning and that the identifier should be treated as an generic meaning and that the identifier should be treated as an
opaque value. In particular, RFC 4291 defines a method by which the opaque value. In particular, RFC 4291 defines a method by which the
Universal and Group bits of an IEEE link-layer address are mapped Universal and Group bits of an IEEE link-layer address are mapped
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Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/. Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on November 26, 2013. This Internet-Draft will expire on February 07, 2014.
Copyright Notice Copyright Notice
Copyright (c) 2013 IETF Trust and the persons identified as the Copyright (c) 2013 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of (http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
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value 000, Interface IDs are required to be 64 bits long and to be value 000, Interface IDs are required to be 64 bits long and to be
constructed in Modified EUI-64 format." constructed in Modified EUI-64 format."
Thus the specification assumes that that the normal case is to Thus the specification assumes that that the normal case is to
transform an Ethernet-style address into an IID, but in practice, transform an Ethernet-style address into an IID, but in practice,
there are various methods of forming such an interface identifier. there are various methods of forming such an interface identifier.
The Modified EUI-64 format preserves the information provided by two The Modified EUI-64 format preserves the information provided by two
particular bits in the MAC address: particular bits in the MAC address:
o The "u" bit in an IEEE address is set to 0 to indicate universal o The "u/l" bit in a MAC address [IEEE802] is set to 0 to indicate
scope (implying uniqueness) or to 1 to indicate local scope universal scope (implying uniqueness) or to 1 to indicate local
(without implying uniqueness). In an IID this bit is inverted, scope (without implying uniqueness). In an IID formed from a MAC
i.e., 1 for universal scope and 0 for local scope. According to address, this bit is simply known as the "u" bit and its value is
RFC 4291 and [RFC5342], the reason for this was to make it easier inverted, i.e., 1 for universal scope and 0 for local scope.
for network operators to manually configure local-scope IIDs. According to RFC 4291 and [RFC5342], the reason for this was to
make it easier for network operators to manually configure local-
scope IIDs.
In an IID, this bit is in position 6, i.e., position 70 in the In an IID, this bit is in position 6, i.e., position 70 in the
complete IPv6 address. complete IPv6 address.
o The "g" bit in an IEEE address is set to 1 to indicate group o The "i/g" bit in a MAC address is set to 1 to indicate group
addressing (link-layer multicast). The value of this bit is addressing (link-layer multicast). The value of this bit is
preserved in an IID. preserved in an IID, where it is known as the "g" bit.
In an IID, this bit is in position 7, i.e., position 71 in the In an IID, this bit is in position 7, i.e., position 71 in the
complete IPv6 address. complete IPv6 address.
This document discusses problems observed with the "u" and "g" bits This document discusses problems observed with the "u" and "g" bits
as a result of the above requirements and the fact that various other as a result of the above requirements and the fact that various other
methods of forming an IID have been defined, quite independently of methods of forming an IID have been defined, quite independently of
the method described in Appendix A of RFC 4291. It then discusses the method described in Appendix A of RFC 4291. It then discusses
the usefulness of these two bits and the significance of the bits in the usefulness of these two bits and the significance of the bits in
an IID in general. Finally it updates RFC 4291 accordingly. an IID in general. Finally it updates RFC 4291 accordingly.
1.1. Terminology 1.1. Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119]. document are to be interpreted as described in [RFC2119].
2. Problem statement 2. Problem statement
In addition to IIDs formed from IEEE EUI-64 addresses, various new In addition to IIDs formed from IEEE EUI-64 addresses, various new
forms of IID have been defined or proposed, such as temporary forms of IID have been defined, including temporary addresses
addresses [RFC4941], Cryptographically Generated Addresses (CGAs) [RFC4941], Cryptographically Generated Addresses (CGAs) [RFC3972],
[RFC3972], Hash-Based Addresses (HBAs) [RFC5535], stable privacy Hash-Based Addresses (HBAs) [RFC5535], and ISATAP addresses
addresses [I-D.ietf-6man-stable-privacy-addresses], or mapped [RFC5214]. Other methods have been proposed, such as stable privacy
addresses [I-D.ietf-6man-stable-privacy-addresses], and mapped
addresses for 4rd [I-D.ietf-softwire-4rd]. In each case, the addresses for 4rd [I-D.ietf-softwire-4rd]. In each case, the
question of how to set the "u" and "g" bits has to be decided. For question of how to set the "u" and "g" bits has to be decided. For
example, RFC 3972 specifies that they are both zero in CGAs, and the example, RFC 3972 specifies that they are both zero in CGAs, and the
same applies to HBAs. On the other hand, RFC 4941 specifies that "u" same applies to HBAs. On the other hand, RFC 4941 specifies that "u"
must be zero but leaves "g" variable. The NAT64 addressing format must be zero but leaves "g" variable. The NAT64 addressing format
[RFC6052] sets the whole byte containing "u" and "g" to zero. [RFC6052] sets the whole byte containing "u" and "g" to zero.
Another case where the "u" and "g" bits are specified is in the Another case where the "u" and "g" bits are specified is in the
Reserved IPv6 Subnet Anycast Address format [RFC2526], which states Reserved IPv6 Subnet Anycast Address format [RFC2526], which states
that "for interface identifiers in EUI-64 format, the universal/local that "for interface identifiers in EUI-64 format, the universal/local
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There was a presumption when IPv6 was designed and the IID format was There was a presumption when IPv6 was designed and the IID format was
first specified that a universally unique IID might prove to be very first specified that a universally unique IID might prove to be very
useful, for example to contribute to solving the multihoming problem. useful, for example to contribute to solving the multihoming problem.
Indeed, the addressing architecture [RFC4291] states this explicitly: Indeed, the addressing architecture [RFC4291] states this explicitly:
"The use of the universal/local bit in the Modified EUI-64 format "The use of the universal/local bit in the Modified EUI-64 format
identifier is to allow development of future technology that can take identifier is to allow development of future technology that can take
advantage of interface identifiers with universal scope." advantage of interface identifiers with universal scope."
However, this has not so far proved to be the case. Also, there is However, this has not so far proved to be the case. Also, there is
evidence from the field that IEEE MAC addresses with "u" = 0 are evidence from the field that IEEE MAC addresses with universal scope
sometime incorrectly assigned to multiple MAC interfaces. Firstly, are sometime incorrectly assigned to multiple MAC interfaces.
there are recurrent reports of manufacturers assigning the same MAC Firstly, there are recurrent reports of manufacturers assigning the
address to multiple devices. Secondly, significant re-use of the same MAC address to multiple devices. Secondly, significant re-use
same virtual MAC address is reported in virtual machine environments. of the same virtual MAC address is reported in virtual machine
Once transformed into IID format (with "u" = 1) these identifiers environments. Once transformed into IID format (with "u" = 1) these
would purport to be universally unique but would in fact be identifiers would purport to be universally unique but would in fact
ambiguous. This has no known harmful effect as long as the be ambiguous. This has no known harmful effect as long as the
replicated MAC addresses and IIDs are used on different layer 2 replicated MAC addresses and IIDs are used on different layer 2
links. If they are used on the same link, of course there will be a links. If they are used on the same link, of course there will be a
problem, to be detected by duplicate address detection [RFC4862], but problem, very likely interfering with link-layer transmission. If
such a problem can usually only be resolved by human intervention. not, the problem will be detected by duplicate address detection
[RFC4862], [RFC6775], but such an error can usually only be resolved
by human intervention.
The conclusion from this is that the "u" bit is not a reliable The conclusion from this is that the "u" bit is not a reliable
indicator of universal uniqueness. indicator of universal uniqueness.
We note that Identifier-Locator Network Protocol (ILNP), a We note that Identifier-Locator Network Protocol (ILNP), a
multihoming solution that might be expected to benefit from multihoming solution that might be expected to benefit from
universally unique IIDs in modified EUI-64 format, does not in fact universally unique IIDs in modified EUI-64 format, does not in fact
rely on them. ILNP uses its own format, defined as a Node Identifier rely on them. ILNP uses its own format, defined as a Node Identifier
[RFC6741]. ILNP has the constraint that a given Node Identifier must [RFC6741]. ILNP has the constraint that a given Node Identifier must
be unique within the context of a given Locator (i.e. within a be unique within the context of a given Locator (i.e. within a single
single given IPv6 subnetwork). As we have just shown, the state of given IPv6 subnetwork). As we have just shown, the state of the "u"
the "u" bit does not in any way guarantee such uniqueness, but bit does not in any way guarantee such uniqueness, but duplicate
duplicate address detection is available. address detection is available.
Thus, we can conclude that the value of the "u" bit in IIDs has no Thus, we can conclude that the value of the "u" bit in IIDs has no
particular meaning. In the case of an IID created from a MAC address particular meaning. In the case of an IID created from a MAC address
according to RFC 4291, its value is determined by the MAC address, according to RFC 4291, its value is determined by the MAC address,
but that is all. but that is all.
An IPv6 IID should not be created from a MAC group address, so the An IPv6 IID should not be created from a MAC group address, so the
"g" bit will normally be zero, but this value also has no particular "g" bit will normally be zero, but this value also has no particular
meaning. Additionally, the "u" and the "g" bits are both meaningless meaning. Additionally, the "u" and the "g" bits are both meaningless
in the format of an IPv6 multicast group ID [RFC3306], [RFC3307]. in the format of an IPv6 multicast group ID [RFC3306], [RFC3307].
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3. Usefulness of the U and G Bits 3. Usefulness of the U and G Bits
Given that the "u" and "g" bits do not have a reliable meaning in an Given that the "u" and "g" bits do not have a reliable meaning in an
IID, it is relevant to consider what usefulness they do have. IID, it is relevant to consider what usefulness they do have.
If an IID is known or guessed to have been created according to RFC If an IID is known or guessed to have been created according to RFC
4291, it could be transformed back into a MAC address. This can be 4291, it could be transformed back into a MAC address. This can be
very helpful during operational fault diagnosis. For that reason, very helpful during operational fault diagnosis. For that reason,
mapping the IEEE "u" and "g" bits into the IID has operational mapping the IEEE "u" and "g" bits into the IID has operational
usefulness. However, it should be stressed that "u" = "g" = 0 does usefulness. However, it should be stressed that an IID with "u" = 1
not prove that an IID was formed from a MAC address; on the contrary, and "g" = 0 might not be formed from a MAC address; on the contrary,
it might equally result from another method. With other methods, it might equally result from another method. With other methods,
there is no reverse transformation available. there is no reverse transformation available.
To the extent that each method of IID creation specifies the values To the extent that each method of IID creation specifies the values
of the "u" and "g" bits, and that each new method is carefully of the "u" and "g" bits, and that each new method is carefully
designed in the light of its predecessors, these bits tend to reduce designed in the light of its predecessors, these bits tend to reduce
the chances of duplicate IIDs. the chances of duplicate IIDs.
4. The Role of Duplicate Address Detection 4. The Role of Duplicate Address Detection
As mentioned above, Duplicate Address Detection (DAD) [RFC4862] is As mentioned above, Duplicate Address Detection (DAD) [RFC4862] is
able to detect any case where a collision of two IIDs on the same able to detect any case where a collision of two IIDs on the same
link leads to a duplicated IPv6 address. The scope of DAD may be link leads to a duplicated IPv6 address. The scope of DAD may be
extended to a set of links by a DAD proxy [I-D.ietf-6man-dad-proxy]. extended to a set of links by a DAD proxy [RFC6957] or by Neighbor
Since DAD is mandatory for all nodes, there will be no case in which Discovery Optimization [RFC6775]. Since DAD is mandatory for all
an IID collision, however unlikely it may be, is not detected. It is nodes, there will be no case in which an IID collision, however
out of scope of most existing specifications to define the recovery unlikely it may be, is not detected. It is out of scope of most
action after a DAD failure, which is an implementation issue. The existing specifications to define the recovery action after a DAD
best procedure to follow will depend on the IID formation method in failure, which is an implementation issue. If a manually created
use. For example, if an IID is formed by some pseudo-random process, IID, or an IID derived from a MAC address according to RFC 4291,
that process could simply be repeated. If a manually created IID, or leads to a DAD failure, human intervention will most likely be
an IID derived from a MAC address according to RFC 4291, leads to a required. However, as mentioned above, some methods of IID formation
DAD failure, human intervention will most likely be required. might produce IID values with "u" = 1 and "g" = 0 that are not based
on a MAC address. With very low probability, such a value might
collide with an IID based on a MAC address.
There is one case in RFC 4862 that requires additional consideration: As stated in RFC 4862:
"On the other hand, if the duplicate link-local address is not formed "On the other hand, if the duplicate link-local address is not formed
from an interface identifier based on the hardware address, which is from an interface identifier based on the hardware address, which is
supposed to be uniquely assigned, IP operation on the interface MAY supposed to be uniquely assigned, IP operation on the interface MAY
be continued." be continued."
However, as mentioned above, some methods of IID formation might Continued operation is only possible if a new IID is created. The
produce IID values with "u" = "g" = 0 that are not based on a MAC best procedure to follow for this will depend on the IID formation
(hardware) address. With very low probability, such a value might method in use. For example, if an IID is formed by a pseudo-random
collide with an IID based on a MAC address. There is no algorithm process, that process could simply be repeated.
for determining whether this case has arisen, rather than a genuine
MAC address collision. Implementers should carefully consider the
consequences of continuing IPv6 operation on the interface in this
unlikely situation.
5. Clarification of Specifications 5. Clarification of Specifications
This section describes clarifications to the IPv6 specifications that This section describes clarifications to the IPv6 specifications that
result from the above discussion. Their aim is to reduce confusion result from the above discussion. Their aim is to reduce confusion
while retaining the useful aspects of the "u" and "g" bits in IIDs. while retaining the useful aspects of the "u" and "g" bits in IIDs.
The EUI-64 to IID transformation defined in the IPv6 addressing The EUI-64 to IID transformation defined in the IPv6 addressing
architecture [RFC4291] MUST be used for all cases where an IPv6 IID architecture [RFC4291] MUST be used for all cases where an IPv6 IID
is derived from an IEEE MAC or EUI-64 address. With any other form is derived from an IEEE MAC or EUI-64 address. With any other form
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these changes. The benefit is that future design discussions are these changes. The benefit is that future design discussions are
simplified. simplified.
6. Security Considerations 6. Security Considerations
No new security exposures or issues are raised by this document. No new security exposures or issues are raised by this document.
7. IANA Considerations 7. IANA Considerations
This document requests no immediate action by IANA. However, the This document requests no immediate action by IANA. However, the
following should be noted when considering future proposed additions following should be noted when considering any future proposed
to the registry of reserved IID values, which requires Standards addition to the registry of reserved IID values, which requires
Action according to [RFC5453]. Standards Action according to [RFC5453].
Full deployment of a new reserved IID value would require updates to Full deployment of a new reserved IID value would require updates to
IID generation code in every deployed IPv6 stack, so the technical IID generation code in every deployed IPv6 stack, so the technical
justification for such a Standards Action would need to be extremely justification for such a Standards Action would need to be extremely
strong. strong.
OPEN ISSUE: Alternatively, we could decide to close the reserved IID
registry completely (which would also mean formally updating RFC
5453). If we choose this approach, the following point can be
deleted. Comments welcome.
A reserved IID, or a range of reserved IIDs, will most likely specify A reserved IID, or a range of reserved IIDs, will most likely specify
values for both "u" and "g", since they are among the high-order values for both "u" and "g", since they are among the high-order
bits. At the present time, none of the known methods of generating bits. At the present time, none of the standard methods of
IIDs will generate "u" = "g" = 1. Reserved IIDs with "u" = "g" = 1 generating IIDs will generate "u" = "g" = 1. Reserved IIDs with "u"
are therefore unlikely to collide with automatically generated IIDs. = "g" = 1 are therefore unlikely to collide with automatically
generated IIDs.
8. Acknowledgements 8. Acknowledgements
Valuable comments were received from Ran Atkinson, Remi Despres, Valuable comments were received from Ran Atkinson, Remi Despres,
Fernando Gont, Brian Haberman, Joel Halpern, Bob Hinden, Christian Ralph Droms, Fernando Gont, Brian Haberman, Joel Halpern, Bob Hinden,
Huitema, Ray Hunter, Mark Smith, and other participants in the 6MAN Christian Huitema, Ray Hunter, Tatuya Jinmei, Mark Smith, Bernie Volz
working group. and other participants in the 6MAN working group.
Brian Carpenter was a visitor at the Computer Laboratory, Cambridge Brian Carpenter was a visitor at the Computer Laboratory, Cambridge
University during part of this work. University during part of this work.
This document was produced using the xml2rfc tool [RFC2629]. This document was produced using the xml2rfc tool [RFC2629].
9. Change log [RFC Editor: Please remove] 9. Change log [RFC Editor: Please remove]
draft-ietf-6man-ug-02: incorporated WG Last Call comments: removed
open issue, clarified IEEE bit names, clarified DAD text, updated
references, minor editorial corrections, 2013-08-06.
draft-ietf-6man-ug-01: emphasised "opaque" nature of IID, added text draft-ietf-6man-ug-01: emphasised "opaque" nature of IID, added text
about DAD failures, expanded IANA considerations, 2013-05-25. about DAD failures, expanded IANA considerations, 2013-05-25.
draft-ietf-6man-ug-00: first WG version, text clarified, added draft-ietf-6man-ug-00: first WG version, text clarified, added
possibility of link-local significance, 2013-03-28. possibility of link-local significance, 2013-03-28.
draft-carpenter-6man-ug-01: numerous clarifications following WG draft-carpenter-6man-ug-01: numerous clarifications following WG
comments, discussed DAD, added new section on the usefulness of the u comments, discussed DAD, added new section on the usefulness of the u
/g bits, expanded IANA considerations, set intended status, /g bits, expanded IANA considerations, set intended status,
2013-02-21. 2013-02-21.
skipping to change at page 9, line 29 skipping to change at page 9, line 29
[RFC5342] Eastlake, D., "IANA Considerations and IETF Protocol Usage [RFC5342] Eastlake, D., "IANA Considerations and IETF Protocol Usage
for IEEE 802 Parameters", BCP 141, RFC 5342, September for IEEE 802 Parameters", BCP 141, RFC 5342, September
2008. 2008.
[RFC5453] Krishnan, S., "Reserved IPv6 Interface Identifiers", RFC [RFC5453] Krishnan, S., "Reserved IPv6 Interface Identifiers", RFC
5453, February 2009. 5453, February 2009.
10.2. Informative References 10.2. Informative References
[I-D.ietf-6man-dad-proxy]
Costa, F., Combes, J., Pougnard, X., and L. Hongyu,
"Duplicate Address Detection Proxy", draft-ietf-6man-dad-
proxy-07 (work in progress), April 2013.
[I-D.ietf-6man-stable-privacy-addresses] [I-D.ietf-6man-stable-privacy-addresses]
Gont, F., "A method for Generating Stable Privacy-Enhanced Gont, F., "A method for Generating Stable Privacy-Enhanced
Addresses with IPv6 Stateless Address Autoconfiguration Addresses with IPv6 Stateless Address Autoconfiguration
(SLAAC)", draft-ietf-6man-stable-privacy-addresses-07 (SLAAC)", draft-ietf-6man-stable-privacy-addresses-10
(work in progress), May 2013. (work in progress), June 2013.
[I-D.ietf-softwire-4rd] [I-D.ietf-softwire-4rd]
Despres, R., Jiang, S., Penno, R., Lee, Y., Chen, G., and Despres, R., Jiang, S., Penno, R., Lee, Y., Chen, G., and
M. Chen, "IPv4 Residual Deployment via IPv6 - a Stateless M. Chen, "IPv4 Residual Deployment via IPv6 - a Stateless
Solution (4rd)", draft-ietf-softwire-4rd-05 (work in Solution (4rd)", draft-ietf-softwire-4rd-06 (work in
progress), April 2013. progress), July 2013.
[IEEE802] , "IEEE Standard for Local and Metropolitan Area Networks:
Overview and Architecture", IEEE Std 802-2001 (R2007) ,
2007.
[RFC2526] Johnson, D. and S. Deering, "Reserved IPv6 Subnet Anycast [RFC2526] Johnson, D. and S. Deering, "Reserved IPv6 Subnet Anycast
Addresses", RFC 2526, March 1999. Addresses", RFC 2526, March 1999.
[RFC2629] Rose, M.T., "Writing I-Ds and RFCs using XML", RFC 2629, [RFC2629] Rose, M., "Writing I-Ds and RFCs using XML", RFC 2629,
June 1999. June 1999.
[RFC3306] Haberman, B. and D. Thaler, "Unicast-Prefix-based IPv6 [RFC3306] Haberman, B. and D. Thaler, "Unicast-Prefix-based IPv6
Multicast Addresses", RFC 3306, August 2002. Multicast Addresses", RFC 3306, August 2002.
[RFC3307] Haberman, B., "Allocation Guidelines for IPv6 Multicast [RFC3307] Haberman, B., "Allocation Guidelines for IPv6 Multicast
Addresses", RFC 3307, August 2002. Addresses", RFC 3307, August 2002.
[RFC3972] Aura, T., "Cryptographically Generated Addresses (CGA)", [RFC3972] Aura, T., "Cryptographically Generated Addresses (CGA)",
RFC 3972, March 2005. RFC 3972, March 2005.
[RFC4941] Narten, T., Draves, R., and S. Krishnan, "Privacy [RFC4941] Narten, T., Draves, R., and S. Krishnan, "Privacy
Extensions for Stateless Address Autoconfiguration in Extensions for Stateless Address Autoconfiguration in
IPv6", RFC 4941, September 2007. IPv6", RFC 4941, September 2007.
[RFC5214] Templin, F., Gleeson, T., and D. Thaler, "Intra-Site
Automatic Tunnel Addressing Protocol (ISATAP)", RFC 5214,
March 2008.
[RFC5535] Bagnulo, M., "Hash-Based Addresses (HBA)", RFC 5535, June [RFC5535] Bagnulo, M., "Hash-Based Addresses (HBA)", RFC 5535, June
2009. 2009.
[RFC6052] Bao, C., Huitema, C., Bagnulo, M., Boucadair, M., and X. [RFC6052] Bao, C., Huitema, C., Bagnulo, M., Boucadair, M., and X.
Li, "IPv6 Addressing of IPv4/IPv6 Translators", RFC 6052, Li, "IPv6 Addressing of IPv4/IPv6 Translators", RFC 6052,
October 2010. October 2010.
[RFC6164] Kohno, M., Nitzan, B., Bush, R., Matsuzaki, Y., Colitti, [RFC6164] Kohno, M., Nitzan, B., Bush, R., Matsuzaki, Y., Colitti,
L., and T. Narten, "Using 127-Bit IPv6 Prefixes on Inter- L., and T. Narten, "Using 127-Bit IPv6 Prefixes on Inter-
Router Links", RFC 6164, April 2011. Router Links", RFC 6164, April 2011.
[RFC6741] Atkinson,, RJ., "Identifier-Locator Network Protocol [RFC6741] Atkinson,, RJ., "Identifier-Locator Network Protocol
(ILNP) Engineering Considerations", RFC 6741, November (ILNP) Engineering Considerations", RFC 6741, November
2012. 2012.
[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.
[RFC6957] Costa, F., Combes, J-M., Pougnard, X., and H. Li,
"Duplicate Address Detection Proxy", RFC 6957, June 2013.
Authors' Addresses Authors' Addresses
Brian Carpenter Brian Carpenter
Department of Computer Science Department of Computer Science
University of Auckland University of Auckland
PB 92019 PB 92019
Auckland 1142 Auckland 1142
New Zealand New Zealand
Email: brian.e.carpenter@gmail.com Email: brian.e.carpenter@gmail.com
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