draft-ietf-dhc-dhcp-privacy-01.txt   draft-ietf-dhc-dhcp-privacy-02.txt 
dhc S. Jiang dhc S. Jiang
Internet-Draft Huawei Technologies Co., Ltd Internet-Draft Huawei Technologies Co., Ltd
Intended status: Informational S. Krishnan Intended status: Informational S. Krishnan
Expires: February 27, 2016 Ericsson Expires: July 2, 2016 Ericsson
T. Mrugalski T. Mrugalski
ISC ISC
August 26, 2015 December 30, 2015
Privacy considerations for DHCPv4 Privacy considerations for DHCPv4
draft-ietf-dhc-dhcp-privacy-01 draft-ietf-dhc-dhcp-privacy-02
Abstract Abstract
DHCP is a protocol that is used to provide addressing and DHCP is a protocol that is used to provide addressing and
configuration information to IPv4 hosts. This document discusses the configuration information to IPv4 hosts. This document discusses the
various identifiers used by DHCP and the potential privacy issues. various identifiers used by DHCP and the potential privacy issues.
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This Internet-Draft is submitted in full conformance with the
skipping to change at page 1, line 35 skipping to change at page 1, line 35
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 February 27, 2016. This Internet-Draft will expire on July 2, 2016.
Copyright Notice Copyright Notice
Copyright (c) 2015 IETF Trust and the persons identified as the Copyright (c) 2015 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Requirements Language and Terminology . . . . . . . . . . . . 3 2. Requirements Language and Terminology . . . . . . . . . . . . 3
3. Identifiers in DHCP . . . . . . . . . . . . . . . . . . . . . 3 3. DHCP Options Carrying Identifiers . . . . . . . . . . . . . . 3
3.1. Client ID Option . . . . . . . . . . . . . . . . . . . . 4 3.1. Client Identifier Option . . . . . . . . . . . . . . . . 4
3.2. Address Fields & Options . . . . . . . . . . . . . . . . 4 3.2. Address Fields & Options . . . . . . . . . . . . . . . . 4
3.3. Client FQDN Option . . . . . . . . . . . . . . . . . . . 4 3.3. Client FQDN Option . . . . . . . . . . . . . . . . . . . 5
3.4. Parameter Request List Option . . . . . . . . . . . . . . 5 3.4. Parameter Request List Option . . . . . . . . . . . . . . 5
3.5. Vendor Class and Vendor-Identifying Vendor Class Options 5 3.5. Vendor Class and Vendor-Identifying Vendor Class Options 5
3.6. Civic Location Option . . . . . . . . . . . . . . . . . . 5 3.6. Civic Location Option . . . . . . . . . . . . . . . . . . 5
3.7. Coordinate-Based Location Option . . . . . . . . . . . . 5 3.7. Coordinate-Based Location Option . . . . . . . . . . . . 6
3.8. Client System Architecture Type Option . . . . . . . . . 6 3.8. Client System Architecture Type Option . . . . . . . . . 6
3.9. Relay Agent Information Option and Sub-options . . . . . 6 3.9. Relay Agent Information Option and Sub-options . . . . . 6
4. Existing Mechanisms That Affect Privacy . . . . . . . . . . . 7 4. Existing Mechanisms That Affect Privacy . . . . . . . . . . . 7
4.1. DNS Updates . . . . . . . . . . . . . . . . . . . . . . . 7 4.1. DNS Updates . . . . . . . . . . . . . . . . . . . . . . . 7
4.2. Allocation strategies . . . . . . . . . . . . . . . . . . 7 4.2. Allocation strategies . . . . . . . . . . . . . . . . . . 7
5. Attacks . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 5. Attacks . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
5.1. Device type discovery . . . . . . . . . . . . . . . . . . 8 5.1. Device type discovery . . . . . . . . . . . . . . . . . . 8
5.2. Operating system discovery . . . . . . . . . . . . . . . 9 5.2. Operating system discovery . . . . . . . . . . . . . . . 9
5.3. Finding location information . . . . . . . . . . . . . . 9 5.3. Finding location information . . . . . . . . . . . . . . 9
5.4. Finding previously visited networks . . . . . . . . . . . 9 5.4. Finding previously visited networks . . . . . . . . . . . 9
5.5. Finding a stable identity . . . . . . . . . . . . . . . . 9 5.5. Finding a stable identity . . . . . . . . . . . . . . . . 9
5.6. Pervasive monitoring . . . . . . . . . . . . . . . . . . 9 5.6. Pervasive monitoring . . . . . . . . . . . . . . . . . . 9
5.7. Finding client's IP address or hostname . . . . . . . . . 9 5.7. Finding client's IP address or hostname . . . . . . . . . 10
5.8. Correlation of activities over time . . . . . . . . . . . 10 5.8. Correlation of activities over time . . . . . . . . . . . 10
5.9. Location tracking . . . . . . . . . . . . . . . . . . . . 10 5.9. Location tracking . . . . . . . . . . . . . . . . . . . . 10
5.10. Leasequery & bulk leasequery . . . . . . . . . . . . . . 10 5.10. Leasequery & bulk leasequery . . . . . . . . . . . . . . 10
6. Security Considerations . . . . . . . . . . . . . . . . . . . 11 6. Security Considerations . . . . . . . . . . . . . . . . . . . 11
7. Privacy Considerations . . . . . . . . . . . . . . . . . . . 11 7. Privacy Considerations . . . . . . . . . . . . . . . . . . . 11
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11
9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 11 9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 11
10. References . . . . . . . . . . . . . . . . . . . . . . . . . 11 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 11
10.1. Normative References . . . . . . . . . . . . . . . . . . 11 10.1. Normative References . . . . . . . . . . . . . . . . . . 11
10.2. Informative References . . . . . . . . . . . . . . . . . 12 10.2. Informative References . . . . . . . . . . . . . . . . . 12
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 13 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 14
1. Introduction 1. Introduction
Dynamic Host Configuration Protocol (DHCP) [RFC2131] is a protocol Dynamic Host Configuration Protocol (DHCP) [RFC2131] is a protocol
that is used to provide addressing and configuration information to that is used to provide addressing and configuration information to
IPv4 hosts. The DHCP protocol uses several identifiers that could IPv4 hosts. The DHCP protocol uses several identifiers that could
become a source for gleaning information about the IPv4 host. This become a source for gleaning information about the IPv4 host. This
information may include device type, operating system information, information may include device type, operating system information,
location(s) that the device may have previously visited, etc. This location(s) that the device may have previously visited, etc. This
document discusses the various identifiers used by DHCP and the document discusses the various identifiers used by DHCP and the
potential privacy issues [RFC6973]. In particular, it also takes potential privacy issues [RFC6973]. In particular, it also takes
into consideration the problem of pervasive monitoring [RFC7258]. into consideration the problem of pervasive monitoring [RFC7258].
Future works may propose protocol changes to fix the privacy issues Future works may propose protocol changes to fix the privacy issues
that have been analyzed in this document. It is out of scope for that have been analyzed in this document. It is out of scope for
this document. this document.
The primary focus of this document is around privacy considerations The primary focus of this document is around privacy considerations
for clients to support client mobility and connection to random for clients to support client mobility and connection to random
networks. The privacy or DHCP servers and relay agents are networks. The privacy of DHCP servers and relay agents are
considered less important as they are typically open for public considered less important as they are typically open for public
services. And, it is generally assumed that relay agent to server services. And, it is generally assumed that relay agent to server
communication is protected from casual snooping, as that communication is protected from casual snooping, as that
communication occurs in the provider's backbone. Nevertheless, the communication occurs in the provider's backbone. Nevertheless, the
topics involving relay agents and servers are explored to some topics involving relay agents and servers are explored to some
degree. However, future work may want to further explore privacy of degree. However, future work may want to further explore privacy of
DHCP servers and relay agents. DHCP servers and relay agents.
2. Requirements Language and Terminology 2. Requirements Language and Terminology
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Stable identifier - Any property disclosed by a DHCP client that Stable identifier - Any property disclosed by a DHCP client that
does not change over time or changes very infrequently and is does not change over time or changes very infrequently and is
unique for said client in a given context. Examples may unique for said client in a given context. Examples may
include MAC address, client-id or a hostname. Some include MAC address, client-id or a hostname. Some
identifiers may be considered stable only under certain identifiers may be considered stable only under certain
conditions, for example one client implementation may keep conditions, for example one client implementation may keep
its client-id stored in stable storage while other may its client-id stored in stable storage while other may
generate it on the fly and use a different one after each generate it on the fly and use a different one after each
boot. Stable identifier may or may not be globally unique. boot. Stable identifier may or may not be globally unique.
3. Identifiers in DHCP 3. DHCP Options Carrying Identifiers
There are several identifiers used in DHCP. This section provides an In DHCP, there are a few options which contain identification
introduction to the various options that will be used further in the information or can be used to extract the identification information
document. about the client. This section enumerates various options and
identifiers conveyed in them, which can be used to disclose client
identification.
3.1. Client ID Option 3.1. Client Identifier Option
The Client Identifier Option [RFC2131] is used to pass an explicit The Client Identifier Option [RFC2131] is used to pass an explicit
client identifier to a DHCP server. client identifier to a DHCP server.
The client identifier is an opaque key, which must be unique to that The client identifier is an opaque key, which must be unique to that
client within the subnet to which the client is attached. It client within the subnet to which the client is attached. It
typically remains stable after it has been initially generated. It typically remains stable after it has been initially generated. It
may contain a hardware address, identical to the contents of the may contain a hardware address, identical to the contents of the
'chaddr' field, or another type of identifier, such as a DNS name. 'chaddr' field, or another type of identifier, such as a DNS name.
[RFC3315] in Section 9.2 specifies DUID-LLT (Link-layer + time) as [RFC3315] in Section 9.2 specifies DUID-LLT (Link-layer + time) as
the recommended DUID type. [RFC4361], Section 6.1 introduces this the recommended DUID (DHCP Unique Identifier) type. [RFC4361],
concept to DHCPv4. Those two document recommend that client Section 6.1 introduces this concept to DHCPv4. Those two document
identifiers be generated by using the permanent link-layer address of recommend that client identifiers be generated by using the permanent
the network interface that the client is trying to configure. link-layer address of the network interface that the client is trying
[RFC4361] updates the recommendation of Client Identifiers to be to configure. [RFC4361] updates the recommendation of Client
"consists of a type field whose value is normally 255, followed by a Identifiers to be "consists of a type field whose value is normally
four-byte IA_ID field, followed by the DUID for the client as defined 255, followed by a four-byte IA_ID field, followed by the DUID for
in RFC 3315, section 9". This does not change the lifecycle of the the client as defined in RFC 3315, section 9". This does not change
Client Identifiers. Clients are expected to generate their Client the lifecycle of the Client Identifiers. Clients are expected to
Identifiers once (during first operation) and store it in a non- generate their Client Identifiers once (during first operation) and
volatile storage or use the same deterministic algorithm to generate store it in a non-volatile storage or use the same deterministic
the same Client Identifier values again. algorithm to generate the same Client Identifier values again.
This means that most implementations will use the available link-
layer address during its first boot. Even if the administrator
enables link-layer address randomization, it is likely that it was
disabled during the first device boot. Hence the original,
unobfuscated link-layer address will likely end up being announced as
client identifier, even if the link- layer address has changed (or
even if being changed on a periodic basis). The exposure of the
original link-layer address in the client identifier will also
undermine other privacy extensions such as [RFC4941].
3.2. Address Fields & Options 3.2. Address Fields & Options
The 'yiaddr' field [RFC2131] in DHCP message is used to allocate The 'yiaddr' field [RFC2131] in DHCP message is used to allocate
address from the server to the client. address from the server to the client.
The DHCPv4 specification [RFC2131] provides a way to specify the The DHCPv4 specification [RFC2131] provides a way to specify the
client link-layer address in the DHCPv4 message header. A DHCPv4 client link-layer address in the DHCPv4 message header. A DHCPv4
message header has 'htype' and 'chaddr' fields to specify the client message header has 'htype' and 'chaddr' fields to specify the client
link-layer address type and the link-layer address, respectively. link-layer address type and the link-layer address, respectively.
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The information contained in the data area of this option is The information contained in the data area of this option is
contained in one or more opaque fields that identify the details of contained in one or more opaque fields that identify the details of
the hardware configuration of the host on which the client is the hardware configuration of the host on which the client is
running, or of industry consortium compliance, for example, the running, or of industry consortium compliance, for example, the
version of the operating system the client is running or the amount version of the operating system the client is running or the amount
of memory installed on the client. of memory installed on the client.
3.6. Civic Location Option 3.6. Civic Location Option
DHCP servers use the Civic Location Option [RFC4776] to delivery of DHCP servers use the Civic Location Option [RFC4776] to deliver of
the location information (the civic and postal addresses) to the DHCP the location information (the civic and postal addresses) to the DHCP
clients. It may refer to three locations: the location of the DHCP clients. It may refer to three locations: the location of the DHCP
server, the location of the network element believed to be closest to server, the location of the network element believed to be closest to
the client, or the location of the client, identified by the "what" the client, or the location of the client, identified by the "what"
element within the option. element within the option.
3.7. Coordinate-Based Location Option 3.7. Coordinate-Based Location Option
The GeoConf and GeoLoc options [RFC6225] is used by DHCP server to The GeoConf and GeoLoc options [RFC6225] is used by DHCP server to
provide the coordinate-based geographic location information to the provide the coordinate-based geographic location information to the
DHCP clients. It enables a DHCP client to obtain its geographic DHCP clients. It enables a DHCP client to obtain its geographic
location. location.
After the relevant DHCP exchanges have taken place, the location
information is stored on the end device rather than somewhere else,
where retrieving it might be difficult in practice.
3.8. Client System Architecture Type Option 3.8. Client System Architecture Type Option
The Client System Architecture Type Option [RFC4578] is used by DHCP The Client System Architecture Type Option [RFC4578] is used by DHCP
client to send a list of supported architecture types to the DHCP client to send a list of supported architecture types to the DHCP
server. It is used to provide configuration information for a node server. It is used by clients that must be booted using the network
that must be booted using the network rather than from local storage. rather than from local storage, so the server can decide which boot
file should be provided to the client.
3.9. Relay Agent Information Option and Sub-options 3.9. Relay Agent Information Option and Sub-options
A DHCP relay agent includes a Relay Agent Information [RFC3046] to A DHCP relay agent includes a Relay Agent Information [RFC3046] to
identify the remote host end of the circuit. It contains a "circuit identify the remote host end of the circuit. It contains a "circuit
ID" sub-option for the incoming circuit, which is an agent-local ID" sub-option for the incoming circuit, which is an agent-local
identifier of the circuit from which a DHCP client-to-server packet identifier of the circuit from which a DHCP client-to-server packet
was received, and a "remote ID" sub-option which provides a trusted was received, and a "remote ID" sub-option which provides a trusted
identifier for the remote high-speed modem. identifier for the remote high-speed modem.
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some provider-specific information with clients' DHCP messages that some provider-specific information with clients' DHCP messages that
is independent of the physical network configuration through which is independent of the physical network configuration through which
the subscriber is connected. The "subscriber-id" assigned by the the subscriber is connected. The "subscriber-id" assigned by the
provider is intended to be stable as customers connect through provider is intended to be stable as customers connect through
different paths, and as network changes occur. The Subscriber-ID is different paths, and as network changes occur. The Subscriber-ID is
an ASCII string, which is assigned and configured by the network an ASCII string, which is assigned and configured by the network
provider. provider.
4. Existing Mechanisms That Affect Privacy 4. Existing Mechanisms That Affect Privacy
This section describes available DHCP mechanisms that one can use to This section describes deployed DHCP mechanisms that affect privacy.
protect or enhance one's privacy.
4.1. DNS Updates 4.1. DNS Updates
DNS Updates [RFC4702] defines a mechanism that allows both clients The Client FQDN (Fully Qualified Domain Name) Option [RFC4702] used
and server to insert into DNS domain information about clients. Both along with DNS Updates [RFC2136] defines a mechanism that allows both
forward (A) and reverse (PTR) resource records can be updated. This clients and server to insert into the DNS domain information about
allows other nodes to conveniently refer to a host, despite the fact clients. Both forward (A) and reverse (PTR) resource records can be
that its IP address may be changing. updated. This allows other nodes to conveniently refer to a host,
despite the fact that its IP address may be changing.
This mechanism exposes two important pieces of information: current This mechanism exposes two important pieces of information: current
address (which can be mapped to current location) and client's address (which can be mapped to current location) and client's
hostname. The stable hostname can then be used to correlate the hostname. The stable hostname can then be used to correlate the
client across different network attachments even when its IP client across different network attachments even when its IP
addresses keep changing. addresses keep changing.
4.2. Allocation strategies 4.2. Allocation strategies
A DHCP server running in typical, stateful mode is given a task of A DHCP server running in typical, stateful mode is given a task of
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Not every allocation strategy is equally suitable for DHCPv4 and for Not every allocation strategy is equally suitable for DHCPv4 and for
DHCPv6. DHCPv6.
Iterative allocation - a server may choose to allocate addresses one Iterative allocation - a server may choose to allocate addresses one
by one. That strategy has the benefit of being very fast, thus can by one. That strategy has the benefit of being very fast, thus can
be favored in deployments that prefer performance. However, it makes be favored in deployments that prefer performance. However, it makes
the allocated addresses very predictable. Also, since the addresses the allocated addresses very predictable. Also, since the addresses
allocated tend to be clustered at the beginning of available pool, it allocated tend to be clustered at the beginning of available pool, it
makes scanning attacks much easier. makes scanning attacks much easier.
Identifier-based allocation - a server may choose to allocate an Identifier-based allocation - some server implementations may choose
address that is based on one of available identifiers, e.g. client to allocate an address that is based on one of available identifiers,
identifier or MAC address. It is also convenient, as returning e.g. client identifier or MAC address. It is also convenient, as
client is very likely to get the same address. Those properties are returning client is very likely to get the same address. Those
convenient for system administrators, so DHCP server implementors are properties are convenient for system administrators, so DHCP server
often requested to implement it. On the other hand, the downside of implementors are often requested to implement it. The downside of
such allocation is that the client has a very stable IP address. such allocation is that the client has a very stable IP address.
That means that correlation of activities over time, location That means that correlation of activities over time, location
tracking, address scanning and OS/vendor discovery apply. This is tracking, address scanning and OS/vendor discovery apply. This is
certainly an issue in DHCPv6, but due to much smaller address space certainly an issue in DHCPv6, but due to much smaller address space
is almost never a problem in DHCPv4. is almost never a problem in DHCPv4.
Hash allocation - it's an extension of identifier based allocation. Hash allocation - it's an extension of identifier based allocation.
Instead of using the identifier directly, it is being hashed first. Instead of using the identifier directly, it is being hashed first.
If the hash is implemented correctly, it removes the flaw of If the hash is implemented correctly, it removes the flaw of
disclosing the identifier, a property that eliminates susceptibility disclosing the identifier, a property that eliminates susceptibility
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Location information is information needed by the access concentrator Location information is information needed by the access concentrator
to forward traffic to a broadband-accessible host. This information to forward traffic to a broadband-accessible host. This information
includes knowledge of the host hardware address, the port or virtual includes knowledge of the host hardware address, the port or virtual
circuit that leads to the host, and/or the hardware address of the circuit that leads to the host, and/or the hardware address of the
intervening subscriber modem. intervening subscriber modem.
Furthermore, the attackers may use DHCP bulk leasequery [RFC6926] Furthermore, the attackers may use DHCP bulk leasequery [RFC6926]
mechanism to obtain bulk information about DHCP bindings, even mechanism to obtain bulk information about DHCP bindings, even
without knowing the target bindings. without knowing the target bindings.
Additionally, active leasequery Additionally, active leasequery [RFC7724] is a mechanism for
[I-D.ietf-dhc-dhcpv4-active-leasequery] is a mechanism for
subscribing to DHCPv4 lease update changes in near real-time. The subscribing to DHCPv4 lease update changes in near real-time. The
intent of this mechanism is to update operator's database, but if intent of this mechanism is to update operator's database, but if
misused, an attacker could defeat server's authentication mechanisms misused, an attacker could defeat server's authentication mechanisms
and subscribe to all updates. He then could continue receiving and subscribe to all updates. He then could continue receiving
updates, without any need for local presence. updates, without any need for local presence.
6. Security Considerations 6. Security Considerations
In current practice, the client privacy and the client authentication In current practice, the client privacy and the client authentication
are mutually exclusive. The client authentication procedure reveals are mutually exclusive. The client authentication procedure reveals
additional client information in their certificates/identifiers. additional client information in their certificates/identifiers.
Full privacy for the clients may mean the clients are also anonymous Full privacy for the clients may mean the clients are also anonymous
for the server and the network. for the server and the network.
7. Privacy Considerations 7. Privacy Considerations
This document at its entirety discusses privacy considerations in This document at its entirety discusses privacy considerations in
DHCP. As such, no dedicated section about this is needed. DHCP. As such, no dedicated discussion is needed.
8. IANA Considerations 8. IANA Considerations
This draft does not request any IANA action. This draft does not request any IANA action.
9. Acknowledgements 9. Acknowledgements
The authors would like to thanks the valuable comments made by The authors would like to thank the valuable comments made by Stephen
Stephen Farrell, Ted Lemon, Ines Robles, Russ White, Christian Farrell, Ted Lemon, Ines Robles, Russ White, Christian Huitema,
Huitema, Bernie Volz and other members of DHC WG. Bernie Volz, Jinmei Tatuya, Marcin Siodelski, Christian Schaefer and
other members of DHC WG.
This document was produced using the xml2rfc tool [RFC2629]. This document was produced using the xml2rfc tool [RFC2629].
10. References 10. References
10.1. Normative References 10.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997, DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>. <http://www.rfc-editor.org/info/rfc2119>.
[RFC2131] Droms, R., "Dynamic Host Configuration Protocol", [RFC2131] Droms, R., "Dynamic Host Configuration Protocol",
RFC 2131, DOI 10.17487/RFC2131, March 1997, RFC 2131, DOI 10.17487/RFC2131, March 1997,
<http://www.rfc-editor.org/info/rfc2131>. <http://www.rfc-editor.org/info/rfc2131>.
[RFC2136] Vixie, P., Ed., Thomson, S., Rekhter, Y., and J. Bound,
"Dynamic Updates in the Domain Name System (DNS UPDATE)",
RFC 2136, DOI 10.17487/RFC2136, April 1997,
<http://www.rfc-editor.org/info/rfc2136>.
[RFC6973] Cooper, A., Tschofenig, H., Aboba, B., Peterson, J., [RFC6973] Cooper, A., Tschofenig, H., Aboba, B., Peterson, J.,
Morris, J., Hansen, M., and R. Smith, "Privacy Morris, J., Hansen, M., and R. Smith, "Privacy
Considerations for Internet Protocols", RFC 6973, Considerations for Internet Protocols", RFC 6973,
DOI 10.17487/RFC6973, July 2013, DOI 10.17487/RFC6973, July 2013,
<http://www.rfc-editor.org/info/rfc6973>. <http://www.rfc-editor.org/info/rfc6973>.
[RFC7258] Farrell, S. and H. Tschofenig, "Pervasive Monitoring Is an [RFC7258] Farrell, S. and H. Tschofenig, "Pervasive Monitoring Is an
Attack", BCP 188, RFC 7258, DOI 10.17487/RFC7258, May Attack", BCP 188, RFC 7258, DOI 10.17487/RFC7258, May
2014, <http://www.rfc-editor.org/info/rfc7258>. 2014, <http://www.rfc-editor.org/info/rfc7258>.
10.2. Informative References 10.2. Informative References
[I-D.ietf-dhc-dhcpv4-active-leasequery]
Kinnear, K., Stapp, M., Volz, B., and N. Russell, "Active
DHCPv4 Lease Query", draft-ietf-dhc-dhcpv4-active-
leasequery-05 (work in progress), August 2015.
[RFC2629] Rose, M., "Writing I-Ds and RFCs using XML", RFC 2629, [RFC2629] Rose, M., "Writing I-Ds and RFCs using XML", RFC 2629,
DOI 10.17487/RFC2629, June 1999, DOI 10.17487/RFC2629, June 1999,
<http://www.rfc-editor.org/info/rfc2629>. <http://www.rfc-editor.org/info/rfc2629>.
[RFC3046] Patrick, M., "DHCP Relay Agent Information Option", [RFC3046] Patrick, M., "DHCP Relay Agent Information Option",
RFC 3046, DOI 10.17487/RFC3046, January 2001, RFC 3046, DOI 10.17487/RFC3046, January 2001,
<http://www.rfc-editor.org/info/rfc3046>. <http://www.rfc-editor.org/info/rfc3046>.
[RFC3315] Droms, R., Ed., Bound, J., Volz, B., Lemon, T., Perkins, [RFC3315] Droms, R., Ed., Bound, J., Volz, B., Lemon, T., Perkins,
C., and M. Carney, "Dynamic Host Configuration Protocol C., and M. Carney, "Dynamic Host Configuration Protocol
skipping to change at page 13, line 33 skipping to change at page 13, line 39
Domain Name (FQDN) Option", RFC 4702, Domain Name (FQDN) Option", RFC 4702,
DOI 10.17487/RFC4702, October 2006, DOI 10.17487/RFC4702, October 2006,
<http://www.rfc-editor.org/info/rfc4702>. <http://www.rfc-editor.org/info/rfc4702>.
[RFC4776] Schulzrinne, H., "Dynamic Host Configuration Protocol [RFC4776] Schulzrinne, H., "Dynamic Host Configuration Protocol
(DHCPv4 and DHCPv6) Option for Civic Addresses (DHCPv4 and DHCPv6) Option for Civic Addresses
Configuration Information", RFC 4776, Configuration Information", RFC 4776,
DOI 10.17487/RFC4776, November 2006, DOI 10.17487/RFC4776, November 2006,
<http://www.rfc-editor.org/info/rfc4776>. <http://www.rfc-editor.org/info/rfc4776>.
[RFC4941] Narten, T., Draves, R., and S. Krishnan, "Privacy
Extensions for Stateless Address Autoconfiguration in
IPv6", RFC 4941, DOI 10.17487/RFC4941, September 2007,
<http://www.rfc-editor.org/info/rfc4941>.
[RFC6225] Polk, J., Linsner, M., Thomson, M., and B. Aboba, Ed., [RFC6225] Polk, J., Linsner, M., Thomson, M., and B. Aboba, Ed.,
"Dynamic Host Configuration Protocol Options for "Dynamic Host Configuration Protocol Options for
Coordinate-Based Location Configuration Information", Coordinate-Based Location Configuration Information",
RFC 6225, DOI 10.17487/RFC6225, July 2011, RFC 6225, DOI 10.17487/RFC6225, July 2011,
<http://www.rfc-editor.org/info/rfc6225>. <http://www.rfc-editor.org/info/rfc6225>.
[RFC6926] Kinnear, K., Stapp, M., Desetti, R., Joshi, B., Russell, [RFC6926] Kinnear, K., Stapp, M., Desetti, R., Joshi, B., Russell,
N., Kurapati, P., and B. Volz, "DHCPv4 Bulk Leasequery", N., Kurapati, P., and B. Volz, "DHCPv4 Bulk Leasequery",
RFC 6926, DOI 10.17487/RFC6926, April 2013, RFC 6926, DOI 10.17487/RFC6926, April 2013,
<http://www.rfc-editor.org/info/rfc6926>. <http://www.rfc-editor.org/info/rfc6926>.
[RFC7724] Kinnear, K., Stapp, M., Volz, B., and N. Russell, "Active
DHCPv4 Lease Query", RFC 7724, DOI 10.17487/RFC7724,
December 2015, <http://www.rfc-editor.org/info/rfc7724>.
Authors' Addresses Authors' Addresses
Sheng Jiang Sheng Jiang
Huawei Technologies Co., Ltd Huawei Technologies Co., Ltd
Q14, Huawei Campus, No.156 Beiqing Road Q14, Huawei Campus, No.156 Beiqing Road
Hai-Dian District, Beijing, 100095 Hai-Dian District, Beijing, 100095
P.R. China P.R. China
Email: jiangsheng@huawei.com Email: jiangsheng@huawei.com
Suresh Krishnan Suresh Krishnan
Ericsson Ericsson
8400 Decarie Blvd. 8400 Decarie Blvd.
Town of Mount Royal, QC Town of Mount Royal, QC
Canada Canada
Phone: +1 514 345 7900 x42871 Phone: +1 514 345 7900 x42871
Email: suresh.krishnan@ericsson.com Email: suresh.krishnan@ericsson.com
Tomek Mrugalski Tomek Mrugalski
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