Homenet                                                       D. Migault
Internet-Draft                                                  Ericsson
Intended status: Standards Track                                R. Weber
Expires: 11 September October 3, 2021                                          Akamai
                                                            T. Mrugalski
                                       Internet Systems Consortium, Inc.
                                                            C. Griffiths

                                                             W. Cloetens
                                                        Deutsche Telekom
                                                           10 March
                                                          April 01, 2021

            DHCPv6 Options for Home Network Naming Authority
         draft-ietf-homenet-naming-architecture-dhc-options-09
         draft-ietf-homenet-naming-architecture-dhc-options-10

Abstract

   This document defines DHCPv6 options so any an agnostic Homenet Naming
   Authority (HNA) can automatically proceed to the appropriate
   configuration and outsource the authoritative naming service for the
   home network.  In most cases, the outsourcing mechanism is
   transparent for the end user.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
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   This Internet-Draft will expire on 11 September October 3, 2021.

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Table of Contents

   1.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
   3.  Protocol Overview . . . . . . . . . . . . . . . . . . . . . .   4   3
   4.  Payload Description . . . . . . . . . . . . . . . . . . . . .   4
     4.1.  Registered Homenet Domain Option  . . . . . . . . . . . .   5
     4.2.  Distribution Master Option  . . . . . . . . . . . . . . .   6   5
       4.2.1.  Supported Transport . . . . . . . . . . . . . . . . .   6
     4.3.  Reverse Distribution Master Server Option . . . . . . . .   7   6
   5.  DHCP Behavior . . . . . . . . . . . . . . . . . . . . . . . .   7
     5.1.  DHCPv6 Server Behavior  . . . . . . . . . . . . . . . . .   7
     5.2.  DHCPv6 Client Behavior  . . . . . . . . . . . . . . . . .   8   7
     5.3.  DHCPv6 Relay Agent Behavior . . . . . . . . . . . . . . .   8
   6.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   8
   7.  Security Considerations"  . . . . . . . . . . . . . . . . . .   8
   8.  Acknowledgments . . . . . . . . . . . . . . . . . . . . . . .   8
   9.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   8
     9.1.  Normative References  . . . . . . . . . . . . . . . . . .   8
     9.2.  Informative References  . . . . . . . . . . . . . . . . .   9  10
   Appendix A.  Scenarios and impact on the End User . . . . . . . .  10  11
   Appendix B.  Base Scenario  . . . . . . . . . . . . . . . . . . .  10  11
     B.1.  Third Party Registered Homenet Domain . . . . . . . . . .  10  11
     B.2.  Third Party DNS Infrastructure  . . . . . . . . . . . . .  11  12
     B.3.  Multiple ISPs . . . . . . . . . . . . . . . . . . . . . .  12
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  13

1.  Terminology

   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
   BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
   capitals, as shown here.

   The reader is expected to be familiar with
   [I-D.ietf-homenet-front-end-naming-delegation] and its terminology
   section.

2.  Introduction

   [I-D.ietf-homenet-front-end-naming-delegation] describes how Homenet
   Naming Authority (HNA) outsources the Public Homenet Zone to an
   Outsourcing Infrastructure.

   This document shows how an ISP can provision automatically the HNA
   with an a DNS Outsourcing Infrastructure (DOI).  Most likely the DOI
   will be - at least partly be - managed or provided by its ISP, but
   other cases may envision the ISP storing some configuration so the
   homenet becomes resilient to HNA replacement.

   The ISP delegates the home network an IP prefix it owns as well as
   the associated reverse zone.
   The ISP is well aware of the owner of that prefix, and as such
   becomes a natural candidate for hosting the Homenet Reverse Zone -
   that is the Reverse Distribution Master (RDM) and potentially the
   Reverse Public Authoritative Servers.

   In addition, the ISP often identifies the home network with a name.
   In most cases, the name is used by the ISP for its internal network
   management operations and is not a name the home network owner has
   registered to.  The ISP may thus leverage such infrastructure and
   provide the homenet a specific domain name designated as per
   [I-D.ietf-homenet-front-end-naming-delegation] a Homenet Registered
   Domain.  Similarly to the reverse zone, the ISP is well aware of who
   owns that domain name and may become a natural candidate for hosting
   the Homenet Zone - that is the Distribution Master (DM) and the
   Public Authoritative Servers.

   This document describes DHCPv6 options that enables the ISP to
   provide the necessary parameters to the HNA, to proceed.
   More specifically, the ISP provides the Registered Homenet Domain,
   necessary information on the DM and the RDM so the HNA can manage and
   upload the Public Homenet Zone and the Reverse Public Homenet Zone as
   described in [I-D.ietf-homenet-front-end-naming-delegation].

   The use of DHCPv6 options makes the configuration completely
   transparent to the end user and provides a similar level of trust as
   the one used to provide the IP prefix.  The link between the HNA and
   the DHCPv6 server may benefit from additional security for example by
   using [I-D.ietf-dhc-sedhcpv6].

3.  Protocol Overview

   This section illustrates how a HNA receives the necessary information
   via DHCPv6 options to outsource its authoritative naming service to
   the DOI.  For the sake of simplicity, and similarly to

   [I-D.ietf-homenet-front-end-naming-delegation], this section assumes
   that the HNA and the home network DHCPv6 client are collocated on the
   CPE.  Note also that this is not mandatory and specific
   communications between the HNA and the DHCPv6 client only are needed.
   In addition, this section assumes the responsible entity for the
   DHCPv6 server is able to configure the DM and RDM.  In our case, this
   means a Registered Homenet Domain can be associated to the DHCP
   client.

   This scenario has been chosen as it is believed to be the most
   popular scenario.  This document does not ignore scenarios where the
   DHCP Server does not have privileged relations with the DM or RDM.
   These cases are discussed latter in Appendix A.  Such scenarios do
   not necessarily require configuration for the end user and can also
   be zero-config.

   The scenario considered in this section is as follows:

   1.  The HNA is willing to outsource the Public Homenet Zone or
       Homenet Reverse Zone and configures its DHCP Client to include in
       its Option Request Option (ORO) the Registered Homnet Homenet Domain
       Option (OPTION_REGISTERED_DOMAIN), the Distribution Master Option
       (OPTION_DIST_MASTER) and the Reverse Distribution Master Option
       (OPTION_REVERSE_DIST_MASTER) option codes.

   2.  The DHCP Server responds to the HNA with the requested DHCPv6
       options based on the identified homenet.  The DHCP Client
       transmits the information to the HNA.

   3.  The HNA is able to get authenticated by the DM and the RDM.  The
       HNA builds the Homenet Zone ( resp. the Homenet Reverse Zone) and
       proceed as described in
       [I-D.ietf-homenet-front-end-naming-delegation].  The DHCPv6
       options provide the necessary and non optional parameters
       described in section 14 of
       [I-D.ietf-homenet-front-end-naming-delegation].  The HNA MAY set
       complement the configurations with additional parameters.
       Section 14 of [I-D.ietf-homenet-front-end-naming-delegation]
       describes such parameters that MAY take a default value.

4.  Payload Description

   This section details the payload of the DHCPv6 options.  <!-- ##
   Client Public Key Option {#sec-key}

   The Client Public Key Option (OPTION_PUBLIC_KEY) indicates the Client
   Public Key that is used to authenticate the HNA.  This option is also
   defined in [I-D.ietf-dhc-sedhcpv6].

    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |     OPTION_PUBLIC_KEY         |         option-len            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                                               |
   /                        Public Key Data                        /
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                     Figure 1: Client Public Key Option

   *  option-code (16 bits): OPTION_PUBLIC_KEY, the option code for the
      Client Public Key Option (TBD1).

   *  option-len (16 bits): length in octets of the option-data field as
      described in [RFC3315].

   *  Client Public Key Data: contains the Client Public Key. The format
      is the DNSKEY RDATA format as defined in [RFC4034].

   -->

4.1.  Registered Homenet Domain Option

   The Registered Domain Option (OPTION_REGISTERED_DOMAIN) indicates the
   FQDN associated to the home network.

    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |   OPTION_REGISTERED_DOMAIN    |         option-len            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                                               |
   /                   Registered Homenet Domain                   /
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                    Figure 2: 1: Registered Domain Option

   *

   o  option-code (16 bits): OPTION_REGISTERED_DOMAIN, the option code
      for the Registered Homenet Domain (TBD2).

   *

   o  option-len (16 bits): length in octets of the option-data field as
      described in [RFC3315].

   * [RFC8415].

   o  Registered Homenet Domain (varaiable): (variable): the FQDN registered for the
      homenet encoded as described in section 10 of [RFC8415].

4.2.  Distribution Master Option

   The Distributed Master Option (OPTION_DIST_MASTER) provides the HNA
   to FQDN of the DM as well as the transport protocol for the
   transaction between the HNA and the DM.

    0                   1                        2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |      OPTION_DIST_MASTER       |          option-len           |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |     Supported Transport       |                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+                               |
   |                                                               |
   /                   Distribution Master  FQDN                   /
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                   Figure 3: 2: Distribution Master Option

   *

   o  option-code (16 bits): OPTION_DIST_MASTER, the option code for the
      DM Option (TBD3).

   *

   o  option-len (16 bits): length in octets of the option-data field as
      described in [RFC3315].

   * [RFC8415].

   o  Supported Transport (16 bits): defines the supported transport by
      the DM.  Each bit represents a supported transport, and a DM MAY
      indicate the support of multiple modes.  The bit for DoT DNS over TLS
      [RFC7858] MUST be set.

   *

   o  Distribution Master FQDN (variable): the FQDN of the DM. DM encoded as
      described in section 10 of [RFC8415].

4.2.1.  Supported Transport

   The Supported Transport filed of the DHCPv6 option indicates the
   supported transport protocol.  Each bit represents a specific
   transport mechanism.  The bit sets to 1 indicates the associated
   transport protocol is supported.  The corresponding bits are assigned
   as described in Figure 4. 3.

   Bit | Transport Protocol | Reference
   ----+--------------------+-----------
    0  | DNS                | This-RFC
    1  | DNS over TLS       |
    1 This-RFC
    2  | DNS over HTTPS     |
   2-7 This-RFC
    3  | DNS over QUIC      | This-RFC
   4-15| unallocated        | This-RFC

                       Figure 4: 3: Supported Protocols

4.3.  Reverse Distribution Master Server Option

   The Reverse Distribution Master Server Option
   (OPTION_REVERSE_DIST_MASTER) provides Transport

   o  DNS: indicates the HNA to FQDN support of the DM as
   well DNS over port 53 as described in
      [RFC1035].

   o  DNS over TLS: indicates the transport protocol for the transaction between the HNA support of DNS over TLS as described
      in [RFC7858].

   o  DNS over HTTPS: indicates the support of DNS over HTTPS as
      described in [RFC8484].

   o  DNS over QUIC: indicates the support of DNS over QUIC as defined
      in [I-D.ietf-dprive-dnsoquic].

4.3.  Reverse Distribution Master Server Option

   The Reverse Distribution Master Server Option
   (OPTION_REVERSE_DIST_MASTER) provides the HNA to FQDN of the DM as
   well as the transport protocol for the transaction between the HNA
   and the DM.

    0                   1                        2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   | OPTION_REVERSE_DIST_MASTER    |          option-len           |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |     Supported Transport       |                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+                               |
   |                                                               |
   /               Reverse Distribution Master FQDN                /
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

               Figure 5: 4: Reverse Distribution Master Option

   *

   o  option-code (16 bits): OPTION_REVERSE_DIST_MASTER, the option code
      for the Reverse Distribution Master Option (TBD4).

   *

   o  option-len (16 bits): length in octets of the option-data field as
      described in [RFC3315].

   * [RFC8415].

   o  Supported Transport (16 bits): defines the supported transport by
      the DM.  Each bit represents a supported transport, and a DM MAY
      indicate the support of multiple modes.  The bit for DoT MUST be
      set.

   *

   o  Reverse Distribution Master FQDN (variable): the FQDN of the RDM. RDM
      encoded as described in section 10 of [RFC8415].

5.  DHCP Behavior

5.1.  DHCPv6 Server Behavior

   Sections 17.2.2 and 18.2 of [RFC3315] [RFC8415] govern server operation in
   regards to option assignment.  As a convenience to the reader, we
   mention here that the server will send option foo only if configured
   with specific values for foo and if the client requested it.  In
   particular, when configured the DHCP Server sends the Registered
   Homenet Domain Option, Distribution Master Option, the Reverse
   Distribution Master Option when requested by the DHCPv6 client by
   including necessary option codes in its ORO.

5.2.  DHCPv6 Client Behavior

   The DHCPv6 client sends a ORO with the necessary option codes:
   Registered Homenet Domain Option, Distribution Master Option, the
   Reverse Distribution Master Option.

   Upon receiving a DHCP option described in this document in the Reply
   message, the HNA SHOULD proceed as described in
   [I-D.ietf-homenet-front-end-naming-delegation].

5.3.  DHCPv6 Relay Agent Behavior

   There are no additional requirements for the DHCP Relay agents.

6.  IANA Considerations

   The DHCP options detailed

   IANA is requested to assign the following new DHCPv6 Option Codes in this document are: *
   OPTION_REGISTERED_DOMAIN:
   the registry maintained in: https://www.iana.org/assignments/dhcpv6-
   parameters/dhcpv6-parameters.xhtml#dhcpv6-parameters-2.

   Value Description                   Client ORO     Singleton Option
   TBD1 * OPTION_DIST_MASTER:  OPTION_REGISTERED_DOMAIN      Yes            Yes
   TBD2 *
   OPTION_REVERSE_DIST_MASTER:  OPTION_DIST_MASTER            Yes            Yes
   TBD3

   The document also requests  OPTION_REVERSE_DIST_MASTER    Yes            Yes

   IANA is requested to maintain a new number space of Supported
   Transport Registry:

   Bit | Transport Protocol | Reference
   ----+--------------------+-----------
    0  | DNS over TLS       |
    1  | DNS over HTTPS     |
   2-7 | unallocated        | parameter in the Distributed Master Option
   (OPTION_DIST_MASTER) or the Reverse Distribution Master Server Option
   (OPTION_REVERSE_DIST_MASTER).  The different parameters are defined
   in Figure 3 in Section 4.2.1.  Future code points 4 - 8 are assigned
   under the IETF Review, other code points are assigned under
   Specification Required as per [RFC8126].

7.  Security Considerations"

8.  Acknowledgments

   We would like to thank Marcin Siodelski and Bernie Volz for their
   comments on the design of the DHCPv6 options.  We would also like to
   thank Mark Andrews, Andrew Sullivan and Lorenzo Colliti for their
   remarks on the architecture design.  The designed solution has been
   largely been inspired by Mark Andrews's document
   [I-D.andrews-dnsop-pd-reverse] as well as discussions with Mark.  We
   also thank Ray Hunter for its reviews, its comments and for
   suggesting an appropriated terminology.

9.  References

9.1.  Normative References

   [I-D.ietf-dprive-dnsoquic]
              Huitema, C., Mankin, A., and S. Dickinson, "Specification
              of DNS over Dedicated QUIC Connections", draft-ietf-
              dprive-dnsoquic-01 (work in progress), October 2020.

   [RFC1034]  Mockapetris, P., "Domain names - concepts and facilities",
              STD 13, RFC 1034, DOI 10.17487/RFC1034, November 1987,
              <https://www.rfc-editor.org/info/rfc1034>.

   [RFC1035]  Mockapetris, P., "Domain names - implementation and
              specification", STD 13, RFC 1035, DOI 10.17487/RFC1035,
              November 1987, <https://www.rfc-editor.org/info/rfc1035>.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <https://www.rfc-editor.org/info/rfc2119>.

   [RFC2181]  Elz, R. and R. Bush, "Clarifications to the DNS
              Specification", RFC 2181, DOI 10.17487/RFC2181, July 1997,
              <https://www.rfc-editor.org/info/rfc2181>.

   [RFC3315]  Droms, R., Ed., Bound, J., Volz, B., Lemon, T., Perkins,
              C., and M. Carney, "Dynamic Host Configuration Protocol
              for IPv6 (DHCPv6)", RFC 3315, DOI 10.17487/RFC3315, July
              2003, <https://www.rfc-editor.org/info/rfc3315>.

   [RFC4034]  Arends, R., Austein, R., Larson, M., Massey, D., and S.
              Rose, "Resource Records for the DNS Security Extensions",
              RFC 4034, DOI 10.17487/RFC4034, March 2005,
              <https://www.rfc-editor.org/info/rfc4034>.

   [RFC6672]  Rose, S. and W. Wijngaards, "DNAME Redirection in the
              DNS", RFC 6672, DOI 10.17487/RFC6672, June 2012,
              <https://www.rfc-editor.org/info/rfc6672>.

   [RFC7858]  Hu, Z., Zhu, L., Heidemann, J., Mankin, A., Wessels, D.,
              and P. Hoffman, "Specification for DNS over Transport
              Layer Security (TLS)", RFC 7858, DOI 10.17487/RFC7858, May
              2016, <https://www.rfc-editor.org/info/rfc7858>.

   [RFC8126]  Cotton, M., Leiba, B., and T. Narten, "Guidelines for
              Writing an IANA Considerations Section in RFCs", BCP 26,
              RFC 8126, DOI 10.17487/RFC8126, June 2017,
              <https://www.rfc-editor.org/info/rfc8126>.

   [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
              2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
              May 2017, <https://www.rfc-editor.org/info/rfc8174>.

   [RFC8415]  Mrugalski, T., Siodelski, M., Volz, B., Yourtchenko, A.,
              Richardson, M., Jiang, S., Lemon, T., and T. Winters,
              "Dynamic Host Configuration Protocol for IPv6 (DHCPv6)",
              RFC 8415, DOI 10.17487/RFC8415, November 2018,
              <https://www.rfc-editor.org/info/rfc8415>.

   [RFC8484]  Hoffman, P. and P. McManus, "DNS Queries over HTTPS
              (DoH)", RFC 8484, DOI 10.17487/RFC8484, October 2018,
              <https://www.rfc-editor.org/info/rfc8484>.

9.2.  Informative References

   [I-D.andrews-dnsop-pd-reverse]
              Andrews, M., "Automated Delegation of IP6.ARPA reverse
              zones with Prefix Delegation", Work draft-andrews-dnsop-pd-
              reverse-02 (work in Progress, Internet-
              Draft, draft-andrews-dnsop-pd-reverse-02, 4 progress), November 2013,
              <http://www.ietf.org/internet-drafts/draft-andrews-dnsop-
              pd-reverse-02.txt>. 2013.

   [I-D.ietf-dhc-sedhcpv6]
              Li, L., Jiang, S., Cui, Y., Jinmei, T., Lemon, T., and D.
              Zhang, "Secure DHCPv6", Work draft-ietf-dhc-sedhcpv6-21 (work
              in Progress, Internet-Draft,
              draft-ietf-dhc-sedhcpv6-21, 21 progress), February 2017,
              <http://www.ietf.org/internet-drafts/draft-ietf-dhc-
              sedhcpv6-21.txt>. 2017.

   [I-D.ietf-homenet-front-end-naming-delegation]
              Migault, D., Weber, R., Richardson, M., Hunter, R.,
              Griffiths, C., and W. Cloetens, "Simple Provisioning of
              Public Names for Residential Networks", Work draft-ietf-
              homenet-front-end-naming-delegation-12 (work in Progress,
              Internet-Draft, draft-ietf-homenet-front-end-naming-
              delegation-12, 2 progress),
              November 2020, <http://www.ietf.org/
              internet-drafts/draft-ietf-homenet-front-end-naming-
              delegation-12.txt>. 2020.

   [I-D.sury-dnsext-cname-dname]
              Sury, O., "CNAME+DNAME Name Redirection", Work draft-sury-
              dnsext-cname-dname-00 (work in
              Progress, Internet-Draft, draft-sury-dnsext-cname-dname-
              00, 15 progress), April 2010, <http://www.ietf.org/internet-drafts/
              draft-sury-dnsext-cname-dname-00.txt>. 2010.

Appendix A.  Scenarios and impact on the End User

   This section details various scenarios and discuss their impact on
   the end user.  This section is not normative and limits the
   description of a limited scope of scenarios that are assumed to be
   representative.  Many other scenarios may be derived from these.

Appendix B.  Base Scenario

   The base scenario is the one described in Section 3 in which an ISP
   manages the DHCP Server, the DM and RDM.

   The end user subscribes to the ISP (foo), and at subscription time
   registers for example.foo as its Registered Homenet Domain
   example.foo.

   In this scenario, the DHCP Server, DM and RDM are managed by the ISP
   so the DHCP Server and as such can provide authentication credentials
   of the HNA to enable secure authenticated transaction with the DM and
   the Reverse DM.

   The main advantage of this scenario is that the naming architecture
   is configured automatically and transparently for the end user.  The
   drawbacks are that the end user uses a Registered Homenet Domain
   managed by the ISP and that it relies on the ISP naming
   infrastructure.

B.1.  Third Party Registered Homenet Domain

   This section considers the case when the end user wants its home
   network to use example.com not managed by her ISP (foo) as a
   Registered Homenet Domain.
   This section still consider the ISP manages the home network and
   still provides example.foo as a Registered Homenet Domain.

   When the end user buys the domain name example.com, it may request to
   redirect the name example.com to example.foo using static redirection
   with CNAME [RFC2181], [RFC1034], DNAME [RFC6672] or CNAME+DNAME
   [I-D.sury-dnsext-cname-dname].

   This configuration is performed once when the domain name example.com
   is registered.  The only information the end user needs to know is
   the domain name assigned by the ISP.  Once this configuration is done
   no additional configuration is needed anymore.  More specifically,
   the HNA may be changed, the zone can be updated as in Appendix B
   without any additional configuration from the end user.

   The main advantage of this scenario is that the end user benefits
   from the Zero Configuration of the Base Scenario Appendix B.  Then,
   the end user is able to register for its home network an unlimited
   number of domain names provided by an unlimited number of different
   third party providers.
   The drawback of this scenario may be that the end user still rely on
   the ISP naming infrastructure.  Note that the only case this may be
   inconvenient is when the DNS Servers provided by the ISPs results in
   high
   latency.Appendix B.  Then, the end user is able to register for its
   home network an unlimited number of domain names provided by an
   unlimited number of different third party providers. latency.

B.2.  Third Party DNS Infrastructure

   This scenario considers that the end user uses example.com as a
   Registered Homenet Domain, and does not want to rely on the
   authoritative servers provided by the ISP.

   In this section we limit the outsourcing to the DM and Public
   Authoritative Server(s) to a third party.  The Reverse Public
   Authoritative Server(s) and the RDM remain managed by the ISP as the
   IP prefix is managed by the ISP.

   Outsourcing to a third party DM can be performed in the following
   ways:

   1.  Updating the DHCP Server Information.  One can imagine a GUI
       interface that enables the end user to modify its profile
       parameters.  Again, this configuration update is done once-for-
       ever.

   2.  Upload the configuration of the DM to the HNA.  In some cases,
       the provider of the CPE hosting the HNA may be the registrar and
       provide the CPE already configured.  In other cases, the CPE may
       request the end user to log into the registrar to validate the
       ownership of the Registered Homenet Domain and agree on the
       necessary credentials to secure the communication between the HNA
       and the DM.  As described in
       [I-D.ietf-homenet-front-end-naming-delegation], such settings
       could be performed in an almost automatic way as to limit the
       necessary interactions with the end user.

B.3.  Multiple ISPs

   This scenario considers a HNA connected to multiple ISPs.

   Suppose the HNA has been configured each of its interfaces
   independently with each ISPS as described in Appendix B.  Each ISP
   provides a different Registered Homenet Domain.

   The protocol and DHCPv6 options described in this document are fully
   compatible with a HNA connected to multiple ISPs with multiple
   Registered Homenet Domains.  However, the HNA should be able to
   handle different Registered Homenet Domains.  This is an
   implementation issue which is outside the scope of the current
   document.

   If a HNA is not able to handle multiple Registered Homenet Domains,
   the HNA may remain connected to multiple ISP with a single Registered
   Homenet Domain.  In this case, one entity is chosen to host the
   Registered Homenet Domain.  This entity may be one of the ISP or a
   third party.  Note that having multiple ISPs can be motivated for
   bandwidth aggregation, or connectivity fail-over.  In the case of
   connectivity fail-over, the fail-over concerns the access network and
   a failure of the access network may not impact the core network where
   the DM Server and Public Authoritative Primaries are hosted.  In that
   sense, choosing one of the ISP even in a scenario of multiple ISPs
   may make sense.  However, for sake of simplicity, this scenario
   assumes that a third party has been chosen to host the Registered
   Homenet Domain.  Configuration is performed as described in
   Appendix B.1 and Appendix B.2.

   With the configuration described in Appendix B.1, the HNA is expect
   to be able to handle multiple Homenet Registered Domain, as the third
   party redirect to one of the ISPs Servers.  With the configuration
   described in Appendix B.2, DNS zone are hosted and maintained by the
   third party.  A single DNS(SEC) Homenet Zone is built and maintained
   by the HNA.  This latter configuration is likely to match most HNA
   implementations.

   The protocol and DHCPv6 options described in this document are fully
   compatible with a HNA connected to multiple ISPs.  To configure or
   not and how to configure the HNA depends on the HNA facilities.
   Appendix B and Appendix B.1 require the HNA to handle multiple
   Registered Homenet Domain, whereas Appendix B.2 does not have such
   requirement.

Authors' Addresses

   Daniel Migault
   Ericsson
   8275 Trans Canada Route
   Saint Laurent, QC  4S 0B6
   Canada

   Email:

   EMail: daniel.migault@ericsson.com
   Ralf Weber
   Akamai

   Email:

   EMail: ralf.weber@akamai.com

   Tomek Mrugalski
   Internet Systems Consortium, Inc.
   950 Charter Street
   Redwood City, City  94063
   United States of America

   Email:
   US

   EMail: tomasz.mrugalski@gmail.com

   Chris Griffiths

   Email:

   EMail: cgriffiths@gmail.com

   Wouter Cloetens
   Deutsche Telekom

   Email:

   EMail: wouter.cloetens@external.telekom.de