intarea                                                  P. Pfister, Ed.
Internet-Draft                                                     Cisco
Intended status: Informational                               D. Schinazi
Expires: January 29, 2018                                       T. Pauly
                                                                   Apple
                                                               E. Vyncke
                                                                   Cisco
                                                              B. Bruneau
                                                     Ecole Polytechnique
                                                           July 28, 2017


             Discovering Provisioning Domain Names and Data
             draft-bruneau-intarea-provisioning-domains-02

Abstract

   An increasing number of hosts and networks are connected to the
   Internet through multiple interfaces, some of which may provide
   multiple ways to access the internet by the mean of multiple IPv6
   prefix configurations.

   This document describes a way for hosts to retrieve additional
   information about their network access characteristics.  The set of
   configuration items required to access the Internet is called a
   Provisioning Domain (PvD) and is identified by a Fully Qualified
   Domain Name (FQDN).  This identifier, retrieved using a new Router
   Advertisement (RA) option, is associated with the set of information
   included within the RA and may later be used to retrieve additional
   information associated with the PvD by the mean of an HTTP request.

Status of This Memo

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

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at http://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on January 29, 2018.




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Copyright Notice

   Copyright (c) 2017 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   3
   3.  Provisioning Domain Identification using Router
       Advertisements  . . . . . . . . . . . . . . . . . . . . . . .   4
     3.1.  PvD ID Option for Router Advertisements . . . . . . . . .   4
     3.2.  Router Behavior . . . . . . . . . . . . . . . . . . . . .   5
     3.3.  Host Behavior . . . . . . . . . . . . . . . . . . . . . .   5
       3.3.1.  DHCPv6 configuration association  . . . . . . . . . .   6
       3.3.2.  DHCPv4 configuration association  . . . . . . . . . .   7
       3.3.3.  Interconnection Sharing by the Host . . . . . . . . .   7
   4.  Provisioning Domain Additional Information  . . . . . . . . .   7
     4.1.  Retrieving the PvD Additional Information . . . . . . . .   7
     4.2.  Providing the PvD Additional Information  . . . . . . . .   9
     4.3.  PvD Additional Information Format . . . . . . . . . . . .   9
       4.3.1.  Connectivity Characteristics Information  . . . . . .  10
       4.3.2.  Private Extensions  . . . . . . . . . . . . . . . . .  11
       4.3.3.  Example . . . . . . . . . . . . . . . . . . . . . . .  11
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .  11
   6.  Privacy Considerations  . . . . . . . . . . . . . . . . . . .  12
   7.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  12
   8.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  12
   9.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  13
     9.1.  Normative references  . . . . . . . . . . . . . . . . . .  13
     9.2.  Informative references  . . . . . . . . . . . . . . . . .  13
   Appendix A.  Changelog  . . . . . . . . . . . . . . . . . . . . .  15
     A.1.  Version 00  . . . . . . . . . . . . . . . . . . . . . . .  15
     A.2.  Version 01  . . . . . . . . . . . . . . . . . . . . . . .  15
     A.3.  Version 02  . . . . . . . . . . . . . . . . . . . . . . .  16
   Appendix B.  Connection monetary cost . . . . . . . . . . . . . .  16
     B.1.  Conditions  . . . . . . . . . . . . . . . . . . . . . . .  17
     B.2.  Price . . . . . . . . . . . . . . . . . . . . . . . . . .  17



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     B.3.  Examples  . . . . . . . . . . . . . . . . . . . . . . . .  18
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  19

1.  Introduction

   It has become very common in modern networks that hosts have internet
   or more specific network access through different networking
   interfaces, tunnels, or next-hop routers.  The concept of
   Provisioning Domain (PvD) was defined in [RFC7556] as a set of
   network configuration information which can be used by hosts in order
   to access the network.

   This specification provides a way to identify explicit PvDs with
   Fully Qualified Domain Names called PvD IDs, which are included in a
   new Router Advertisement [RFC4861] option.  This new option, when
   present, is used to associate the correlated set of configuration
   information with the identified PvD.  It is worth noting that
   multiple PvDs with different PvD IDs could be provisioned on any host
   interface, as well as noting that the same PvD ID could be used on
   different interfaces in order to inform the host that both PvDs, on
   different interfaces, ultimately provide identical services.

   This document also introduces a way for hosts to retrieve additional
   information related to a specific PvD by the mean of an HTTP-over-TLS
   query using an URI derived from the PvD ID.  The retrieved JSON
   object contains additional network information that would typically
   be considered unfit, or too large, to be directly included in the
   Router Advertisements.  This information can be used by the
   networking stack, the applications, or even be partially displayed to
   the users (e.g., by displaying a localized network service name).

2.  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
   [RFC2119].

   In addition, this document uses the following terminology:

   PvD:   A Provisioning Domain, a set of network configuration
      information; for more information, see [RFC7556].

   PvD ID:   A Fully Qualified Domain Name (FQDN) used to identify a
      PvD.

   Explicit PvD:   A PvD uniquely identified with a PvD ID. for more
      information, see [RFC7556].



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   Implicit PvD:   A PvD associated with a set of configuration
      information that, in the absence of a PvD ID, is associated with
      the advertising router.

3.  Provisioning Domain Identification using Router Advertisements

   Each provisioning domain is identified by a PvD ID.  The PvD ID is a
   Fully Qualified Domain Name (FQDN) which MUST belong to the network
   operator in order to avoid ambiguity.  The same PvD ID MAY be used in
   several access networks when the set of configuration information is
   identical (e.g. in all home networks subscribed to the same service).

3.1.  PvD ID Option for Router Advertisements

   This document introduces a new Router Advertisement (RA) option
   called the PvD ID Router Advertisement Option, used to convey the
   FQDN identifying a given PvD.

    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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |     Type      |    Length     |H|L|         Reserved          |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |           Sequence            |                             ...
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+          PvD ID FQDN        ...
   ...                                                           ...
   ...             +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   ...             |                  Padding                      |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                PvD ID Router Advertisements Option format

   Type        :   (8 bits) To be defined by IANA.

   Length      :   (8 bits) The length of the option (including the Type
      and Length fields) in units of 8 octets.

   H-flag      :   (1 bit) Whether some PvD Additional Information is
      made available through HTTP over TLS, as described in Section 4.

   L-flag      :   (1 bit) Whether the router is also providing IPv4
      access using DHCPv4 (see Section 3.3.2).

   Reserved    :   (14 bits) Reserved for later use.  It MUST be set to
      zero by the sender and ignored by the receiver.

   Sequence    :   (16 bits) Sequence number for the PvD Additional
      Information, as described in Section 4.



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   PvD ID FQDN :   An ASCII string representation of the FQDN used as
      PvD ID.  The string ends at the first byte set to zero, or the end
      of the option, whichever comes first.

   Padding     :   Zero or more padding octets such as to set the option
      length (Type and Length fields included) to eight times the value
      of the Length field.  It MUST be set to zero by the sender and
      ignored by the receiver.

   Routers MUST NOT include more than one PvD ID Router Advertisement
   Option in each RA.  In case multiple PvD ID options are found in a
   given RA, hosts MUST ignore all but the first PvD ID option.

   Note: The existence and/or size of the sequence number is subject to
   discussion.  The validity of a PvD Additional Information object is
   included in the object itself, but this only allows for 'pull based'
   updates, whereas the RA options usually provide 'push based' updates.

3.2.  Router Behavior

   A router MAY insert at most one PvD ID Option in its RAs.  The
   included PvD ID is associated with all the other options included in
   the same RA (e.g., Prefix Information [RFC4861], Recursive DNS Server
   [RFC6106], Routing Information [RFC4191] options).

   In order to provide multiple independent PvDs, a router MUST send
   multiple RAs using different source link-local addresses (LLA) (as
   proposed in [I-D.bowbakova-rtgwg-enterprise-pa-multihoming]), each of
   which MAY include a PvD ID option.  In such cases, routers MAY
   originate the different RAs using the same datalink layer address.

   If the router is actually a VRRP instance [RFC5798], then the
   procedure is identical except that the virtual datalink layer address
   is used as well as the virtual IPv6 addresses.

3.3.  Host Behavior

   RAs are used to configure IPv6 hosts.  When a host receives an RA
   message including a PvD ID Option, it MUST associate all the
   configuration objects which are updated by the received RA (e.g.,
   Prefix Information [RFC4861], Recursive DNS Server [RFC6106], Routing
   Information [RFC4191] options) with the PvD identified by the PvD ID
   Option, even if some objects are already ssociated with a different
   explicit or implicit PvD.

   If the received RA does not include a PvD ID Option, the host MUST
   associate the configuration objects which are updated by the received
   RA with an implicit PvD, even if some objects were already associated



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   with a different explicit or implicit PvD.  This implicit PvD is
   identified by the link-local address of the router sending the RA and
   the interface on which the RA was received.

   This document does not update the way Router Advertisement options
   are processed.  But in addition to the option processing defined in
   other documents, hosts implementing this specification MUST associate
   each created or updated object (e.g. address, default route, more
   specific route, DNS server list) with the PvD associated with the
   received RA.

   Note: There is a discussion whether there can be multiple implicit
   PvDs on a single interface (i.e. whether the router link-local
   address should be used to identify the implicit PvDs).

   While resolving names, executing the default address selection
   algorithm [RFC6724] or executing the default router selection
   algorithm ([RFC2461], [RFC4191] and [RFC8028]), hosts MAY consider
   only the configuration associated with an arbitrary set of PvDs.

   For example, a host MAY associate a given process with a specific
   PvD, or a specific set of PvDs, while associating another process
   with another PvD.  A PvD-aware application might also be able to
   select, on a per-connection basis, which PvDs should be used for a
   given connection.  In particular, constrained devices such as small
   battery operated devices (e.g. IoT), or devices with limited CPU or
   memory resources may purposefully use a single PvD while ignoring
   some received RAs containing different PvD IDs.

   The way an application expresses its desire to use a given PvD, or a
   set of PvDs, or the way this selection is enforced, is out of the
   scope of this document.  Useful insights about these considerations
   can be found in [I-D.kline-mif-mpvd-api-reqs].

3.3.1.  DHCPv6 configuration association

   When a host retrieves configuration elements using DHCPv6, they MUST
   be associated with the explicit or implicit PvD of the RA received on
   the same interface, using the same link-local address, and with the
   O-flag set [RFC4861].  If no such PvD is found, or whenever multiple
   different PvDs are found, the host behavior is unspecified.

   This process requires hosts to keep track of received RAs, associated
   PvD IDs, and routers link-local addresses.







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3.3.2.  DHCPv4 configuration association

   When a host retrieves configuration elements from DHCPv4, they MUST
   be associated with the explicit PvD received on the same interface,
   whose PVD ID Options L-flag is set and, in the case of a non point-
   to-point link, using the same link-layer address.  If no such PvD is
   found, or whenever multiple different PvDs are found, the
   configuration elements coming from DHCPv4 MUST be associated with an
   IPv4-only implicit PvD identified by the interface on which the
   DHCPv4 transaction happened.

3.3.3.  Interconnection Sharing by the Host

   The situation when a host becomes also a router by acting as a router
   or ND proxy on a different interface (such as WiFi) to share the
   connectivity of another interface (such as cellular), also known as
   "tethering" is TBD but it is expected that the one or several PvD
   associated to the shared interface will also be advertised to the
   clients.

4.  Provisioning Domain Additional Information

   Once a new PvD ID is discovered, it may be used to retrieve
   additional information about the characteristics of the provided
   connectivity.  This set of information is called PvD Additional
   Information, and is encoded as a JSON object [RFC7159].

   The purpose of this additional set of information is to securely
   provide additional information to hosts about the connectivity that
   is provided using a given interface and source address pair.  It
   typically includes data that would be considered too large, or not
   critical enough, to be provided within an RA option.  The information
   contained in this object MAY be used by the operating system, network
   libraries, applications, or users, in order to decide which set of
   PvDs should be used for which connection, as described in
   Section 3.3.

4.1.  Retrieving the PvD Additional Information

   When the H-flag of the PvD ID Option is set, hosts MAY attempt to
   retrieve the PvD Additional Information associated with a given PvD
   by performing an HTTP over TLS [RFC2818] GET query to https://<PvD-ID
   >/.well-known/pvd [RFC5785].  Inversely, hosts MUST NOT do so
   whenever the H-flag is not set.

   Note: Should the PvD AI retrieval be a MAY or a SHOULD ? Could the
   object contain critical data, or should it only contain informational
   data ?



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   Note that the DNS name resolution of <PvD-ID> as well as the actual
   query MUST be performed using the PvD associated with the PvD ID.  In
   other words, the name resolution, source address selection, as well
   as the next-hop router selection MUST be performed while using
   exclusively the set of configuration information attached with the
   PvD, as defined in Section 3.3.  In some cases, it may therefore be
   necessary to wait for an address to be available for use (e.g., once
   the Duplicate Address Detection or DHCPv6 processes are complete)
   before initiating the HTTP over TLS query.

   If the HTTP status of the answer is greater than or equal to 400 the
   host MUST abandon and consider that there is no additional PvD
   information.  If the HTTP status of the answer is between 300
   included and 399 included it MUST follow the redirection(s).  If the
   HTTP status of the answer is between 200 included and 299 included
   the host MAY get a file containing a single JSON object.  When a JSON
   object could not be retrieved, an error message SHOULD be logged and/
   or displayed in a rate-limited fashion.

   After retrieval of the PvD Additional Information, hosts MUST watch
   the PvD ID Sequence field for change.  In case a different value than
   the one in the RA Sequence field is observed, or whenever the
   validity time included in the PVD Additional Information JSON object
   is expired, hosts MUST either perform a new query and retrieve a new
   version of the object, or deprecate the object and stop using it.

   Hosts retrieving a new PvD Additional Information object MUST check
   for the presence and validity of the mandatory fields Section 4.3.  A
   retrieved object including an outdated expiration time or missing a
   mandatory element MUST be ignored.  In order to avoid traffic spikes
   toward the server hosting the PvD Additional Information when an
   object expires, a host which last retrieved an object at a time A,
   including a validity time B, SHOULD renew the object at a uniformly
   random time in the interval [(B-A)/2,A].

   The PvD Additional Information object includes a set of IPv6 prefixes
   which MUST be checked against all the Prefix Information Options
   advertised in the Router Advertisement.  If any of the prefixes
   included in the Prefix Information Options is not included in at
   least one of the listed prefixes, the PvD associated with the tested
   prefix MUST be considered unsafe and MUST NOT be used.  While this
   does not prevent a malicious network provider, it does complicate
   some attack scenarios, and may help detecting misconfiguration.

   The server providing the JSON files SHOULD also check whether the
   client address is part of the prefixes listed into the additional
   information and SHOULD return a 403 response code if there is no




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   match.  The server MAY also use the client address to select the
   right JSON object to be returned.

4.2.  Providing the PvD Additional Information

   Whenever the H-flag is set in the PvD RA Option, a valid PvD
   Additional Information object MUST be made available to all hosts
   receiving the RA.  In particular, when a captive portal is present,
   hosts MUST still be allowed to access the object, even before logging
   into the captive portal.

   Routers MAY increment the PVD ID Sequence number in order to inform
   host that a new PvD Additional Information object is available and
   should be retrieved.

4.3.  PvD Additional Information Format

   The PvD Additional Information is a JSON object.

   The following array presents the mandatory keys which MUST be
   included in the object:

   +----------+-------------------+-----------+------------------------+
   | JSON key | Description       | Type      | Example                |
   +----------+-------------------+-----------+------------------------+
   | name     | Human-readable    | UTF-8     | "Awesome Wifi"         |
   |          | service name      | string    |                        |
   | expires  | Date after which  | [RFC3339] | "2017-07-23T06:00:00Z" |
   |          | this object is    |           |                        |
   |          | not valid         |           |                        |
   | prefixes | Array of IPv6     | Array of  | ["2001:db8:1::/48",    |
   |          | prefixes valid    | strings   | "2001:db8:4::/48"]     |
   |          | for this PVD      |           |                        |
   +----------+-------------------+-----------+------------------------+

   A retrieved object which does not include a valid string associated
   with the "name" key at the root of the object, or a valid date
   associated with the "expiration" key, also at the root of the object,
   MUST be ignored.  In such cases, an error message SHOULD be logged
   and/or displayed in a rate-limited fashion.

   The following table presents some optional keys which MAY be included
   in the object.








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   +-----------------+-----------------------+---------+---------------+
   | JSON key        | Description           | Type    | Example       |
   +-----------------+-----------------------+---------+---------------+
   | localizedName   | Localized user-       | UTF-8   | "Wifi Genial" |
   |                 | visible service name, | string  |               |
   |                 | language can be       |         |               |
   |                 | selected based on the |         |               |
   |                 | HTTP Accept-Language  |         |               |
   |                 | header in the         |         |               |
   |                 | request.              |         |               |
   | noInternet      | No Internet, set when | boolean | true          |
   |                 | the PvD only provides |         |               |
   |                 | restricted access to  |         |               |
   |                 | a set of services.    |         |               |
   | characteristics | Connectivity          | JSON    | See Section   |
   |                 | characteristics       | object  | 4.3.1         |
   | metered         | metered, when the     | boolean | false         |
   |                 | access volume is      |         |               |
   |                 | limited.              |         |               |
   +-----------------+-----------------------+---------+---------------+

   It is worth noting that the JSON format allows for extensions.
   Whenever an unknown key is encountered, it MUST be ignored along with
   its associated elements.

4.3.1.  Connectivity Characteristics Information

   The following set of keys can be used to signal certain
   characteristics of the connection towards the PvD.

   They should reflect characteristics of the overall access technology
   which is not limited to the link the host is connected to, but rather
   a combination of the link technology, CPE upstream connectivity, and
   further quality of service considerations.

   +---------------+--------------+---------------------+--------------+
   | JSON key      | Description  | Type                | Example      |
   +---------------+--------------+---------------------+--------------+
   | maxThroughput | Maximum      | object({down(int),  | {"down":     |
   |               | achievable   | up(int)}) in kb/s   | 10000, "up": |
   |               | throughput   |                     | 5000}        |
   | minLatency    | Minimum      | object({down(int),  | {"down": 10, |
   |               | achievable   | up(int)}) in ms     | "up": 20}    |
   |               | latency      |                     |              |
   | rl            | Maximum      | object({down(int),  | {"down":     |
   |               | achievable   | up(int)}) in losses | 0.1, "up":   |
   |               | reliability  | every 1000 packets  | 1}           |
   +---------------+--------------+---------------------+--------------+



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4.3.2.  Private Extensions

   JSON keys starting with "x-" are reserved for private use and can be
   utilized to provide information that is specific to vendor, user or
   enterprise.  It is RECOMMENDED to use one of the patterns "x-FQDN-
   KEY" or "x-PEN-KEY" where FQDN is a fully qualified domain name or
   PEN is a private enterprise number [PEN] under control of the author
   of the extension to avoid collisions.

4.3.3.  Example

   Here are two examples based on the keys defined in this section.

   {
     "name": "Foo Wireless",
     "localizedName": "Foo-France Wifi",
     "expires": "2017-07-23T06:00:00Z",
     "prefixes" : ["2001:db8:1::/48", "2001:db8:4::/48"],
     "characteristics": {
      "maxThroughput": { "down":200000, "up": 50000 },
      "minLatency": { "down": 0.1, "up": 1 }
     }
   }

   {
     "name": "Bar 4G",
     "localizedName": "Bar US 4G",
     "expires": "2017-07-23T06:00:00Z",
     "prefixes": ["2001:db8:1::/48", "2001:db8:4::/48"],
     "metered": true,
     "characteristics": {
       "maxThroughput": { "down":80000, "up": 20000 }
     }
   }

5.  Security Considerations

   Although some solutions such as IPsec or SEND [RFC3971] can be used
   in order to secure the IPv6 Neighbor Discovery Protocol, actual
   deployments largely rely on link layer or physical layer security
   mechanisms (e.g. 802.1x [IEEE8021X]) in conjunction with RA Guard
   [RFC6105].

   This specification does not improve the Neighbor Discovery Protocol
   security model, but extends the purely link-local configuration
   retrieval mechanisms with HTTP-over-TLS communications.





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   During the exchange, the server authenticity is verified by the mean
   of a certificate, validated based on the FQDN found in the Router
   Advertisement (e.g. using a list of pre-installed CA certificates, or
   DNSSec [RFC4035] with DNS Based Authentication of Named Entities
   [RFC6698]).  This authentication creates a secure binding between the
   information provided by the trusted Router Advertisement, and the
   HTTP server.  But this does not mean the Advertising Router and the
   PvD server belong to the same entity.

   The IPv6 prefixes list included in the PvD Additional Information
   JSON object is used to validate that the prefixes included in the
   Router Advertisements are really part of the PvD.  An adversarial
   router willing to fake the use of a given explicit PvD, without any
   access to the actual PvD, would need to perform NAT66 in order to
   circumvent this check.

   It is also RECOMMENDED that the PvD server checks the source
   addresses of incoming connexions (see Section 4.1).  This check
   ensures that the internet access provided by any router advertising a
   given PvD eventually reaches the internet using the actual PvD
   (Tunneling can still be used).

   For privacy reasons, it is desirable that the PvD Additional
   Information object may only be retrieved by the hosts using the given
   PvD.  Host identity SHOULD be validated based on the client address
   that is used during the HTTP query.

6.  Privacy Considerations

   TBD

7.  IANA Considerations

   IANA is kindly requested to allocate a new IPv6 Neighbor Discovery
   option number for the PvD ID Router Advertisement option.

   The URI used to retrieve the PvD Additional Information JSON object
   is the well known URI (see [RFC5785]) with the URI suffix "pvd".

   TBD: JSON keys will need a new registry.

8.  Acknowledgements

   Many thanks to M. Stenberg and S. Barth for their earlier work:
   [I-D.stenberg-mif-mpvd-dns].






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   Thanks also to Ray Bellis, Lorenzo Colitti, Thierry Danis, Marcus
   Keane, Erik Kline, Jen Lenkova, Mark Townsley, James Woodyatt and
   Mikael Abrahamson for useful and interesting discussions.

   Finally, many thanks to Thierry Danis for his implementation work
   ([github]), Tom Jones for his integration effort into the Neat
   project and Rigil Salim for his implementation work.

9.  References

9.1.  Normative references

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC2461]  Narten, T., Nordmark, E., and W. Simpson, "Neighbor
              Discovery for IP Version 6 (IPv6)", RFC 2461, December
              1998.

   [RFC2818]  Rescorla, E., "HTTP Over TLS", RFC 2818, DOI 10.17487/
              RFC2818, May 2000,
              <http://www.rfc-editor.org/info/rfc2818>.

   [RFC4861]  Narten, T., Nordmark, E., Simpson, W., and H. Soliman,
              "Neighbor Discovery for IP version 6 (IPv6)", RFC 4861,
              September 2007.

   [RFC7159]  Bray, T., Ed., "The JavaScript Object Notation (JSON) Data
              Interchange Format", RFC 7159, DOI 10.17487/RFC7159, March
              2014, <http://www.rfc-editor.org/info/rfc7159>.

9.2.  Informative references

   [RFC3339]  Klyne, G. and C. Newman, "Date and Time on the Internet:
              Timestamps", RFC 3339, DOI 10.17487/RFC3339, July 2002,
              <http://www.rfc-editor.org/info/rfc3339>.

   [RFC3971]  Arkko, J., Kempf, J., Zill, B., and P. Nikander, "SEcure
              Neighbor Discovery (SEND)", RFC 3971, March 2005.

   [RFC4035]  Arends, R., Austein, R., Larson, M., Massey, D., and S.
              Rose, "Protocol Modifications for the DNS Security
              Extensions", RFC 4035, DOI 10.17487/RFC4035, March 2005,
              <http://www.rfc-editor.org/info/rfc4035>.

   [RFC4191]  Draves, R. and D. Thaler, "Default Router Preferences and
              More-Specific Routes", RFC 4191, November 2005.




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   [RFC5785]  Nottingham, M. and E. Hammer-Lahav, "Defining Well-Known
              Uniform Resource Identifiers (URIs)", RFC 5785, DOI
              10.17487/RFC5785, April 2010,
              <http://www.rfc-editor.org/info/rfc5785>.

   [RFC5798]  Nadas, S., Ed., "Virtual Router Redundancy Protocol (VRRP)
              Version 3 for IPv4 and IPv6", RFC 5798, DOI 10.17487/
              RFC5798, March 2010,
              <http://www.rfc-editor.org/info/rfc5798>.

   [RFC6105]  Levy-Abegnoli, E., Van de Velde, G., Popoviciu, C., and J.
              Mohacsi, "IPv6 Router Advertisement Guard", RFC 6105, DOI
              10.17487/RFC6105, February 2011,
              <http://www.rfc-editor.org/info/rfc6105>.

   [RFC6106]  Jeong, J., Park, S., Beloeil, L., and S. Madanapalli,
              "IPv6 Router Advertisement Options for DNS Configuration",
              RFC 6106, November 2010.

   [RFC6698]  Hoffman, P. and J. Schlyter, "The DNS-Based Authentication
              of Named Entities (DANE) Transport Layer Security (TLS)
              Protocol: TLSA", RFC 6698, DOI 10.17487/RFC6698, August
              2012, <http://www.rfc-editor.org/info/rfc6698>.

   [RFC6724]  Thaler, D., Draves, R., Matsumoto, A., and T. Chown,
              "Default Address Selection for Internet Protocol Version 6
              (IPv6)", RFC 6724, September 2012.

   [RFC7556]  Anipko, D., Ed., "Multiple Provisioning Domain
              Architecture", RFC 7556, DOI 10.17487/RFC7556, June 2015,
              <http://www.rfc-editor.org/info/rfc7556>.

   [RFC8028]  Baker, F. and B. Carpenter, "First-Hop Router Selection by
              Hosts in a Multi-Prefix Network", RFC 8028, DOI 10.17487/
              RFC8028, November 2016,
              <http://www.rfc-editor.org/info/rfc8028>.

   [I-D.bowbakova-rtgwg-enterprise-pa-multihoming]
              Baker, F., Bowers, C., and J. Linkova, "Enterprise
              Multihoming using Provider-Assigned Addresses without
              Network Prefix Translation: Requirements and Solution",
              draft-bowbakova-rtgwg-enterprise-pa-multihoming-01 (work
              in progress), October 2016.

   [I-D.stenberg-mif-mpvd-dns]
              Stenberg, M. and S. Barth, "Multiple Provisioning Domains
              using Domain Name System", draft-stenberg-mif-mpvd-dns-00
              (work in progress), October 2015.



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   [I-D.kline-mif-mpvd-api-reqs]
              Kline, E., "Multiple Provisioning Domains API
              Requirements", draft-kline-mif-mpvd-api-reqs-00 (work in
              progress), November 2015.

   [PEN]      IANA, "Private Enterprise Numbers", <https://www.iana.org/
              assignments/enterprise-numbers>.

   [IEEE8021X]
              IEEE, "IEEE Standards for Local and Metropolitan Area
              Networks: Port based Network Access Control, IEEE Std", .

   [github]   Cisco, "IPv6-mPvD github repository", <https://github.com/
              IPv6-mPvD>.

Appendix A.  Changelog

   Note to RFC Editors: Remove this section before publication.

A.1.  Version 00

   Initial version of the draft.  Edited by Basile Bruneau + Eric Vyncke
   and based on Basile's work.

A.2.  Version 01

   Major rewrite intended to focus on the the retained solution based on
   corridors, online, and WG discussions.  Edited by Pierre Pfister.
   The following list only includes major changes.

      PvD ID is an FQDN retrieved using a single RA option.  This option
      contains a sequence number for push-based updates, a new H-flag,
      and a L-flag in order to link the PvD with the IPv4 DHCP server.

      A lifetime is included in the PvD ID option.

      Detailed Hosts and Routers specifications.

      Additional Information is retrieved using HTTP-over-TLS when the
      PvD ID Option H-flag is set.  Retrieving the object is optional.

      The PvD Additional Information object includes a validity date.

      DNS-based approach is removed as well as the DNS-based encoding of
      the PvD Additional Information.

      Major cut in the list of proposed JSON keys.  This document may be
      extended later if need be.



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      Monetary discussion is moved to the appendix.

      Clarification about the 'prefixes' contained in the additional
      information.

      Clarification about the processing of DHCPv6.

A.3.  Version 02

      The FQDN is now encoded with ASCII format (instead of DNS binary)
      in the RA option.

      The PvD ID option lifetime is removed from the object.

      Use well known URI "https://<PvD-ID>/.well-known/pvd"

      Reference RFC3339 for JSON timestamp format.

      The PvD ID Sequence field has been extended to 16 bits.

      Modified host behavior for DHCPv4 and DHCPv6.

      Removed IKEv2 section.

      Removed mention of RFC7710 Captive Portal option.  A new I.D.
      will be proposed to address the captive portal use case.

Appendix B.  Connection monetary cost

   NOTE: This section is included as a request for comment on the
   potential use and syntax.

   The billing of a connection can be done in a lot of different ways.
   The user can have a global traffic threshold per month, after which
   his throughput is limited, or after which he/she pays each megabyte.
   He/she can also have an unlimited access to some websites, or an
   unlimited access during the weekends.

   An option is to split the bill in elementary billings, which have
   conditions (a start date, an end date, a destination IP address...).
   The global billing is an ordered list of elementary billings.  To
   know the cost of a transmission, the host goes through the list, and
   the first elementary billing whose the conditions are fulfilled gives
   the cost.  If no elementary billing conditions match the request, the
   host MUST make no assumption about the cost.






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B.1.  Conditions

   Here are the potential conditions for an elementary billing.  All
   conditions MUST be fulfill.

   +-----------+-------------+---------------+-------------------------+
   | Key       | Description | Type          | JSON Example            |
   +-----------+-------------+---------------+-------------------------+
   | beginDate | Date before | ISO 8601      | "1977-04-22T06:00:00Z"  |
   |           | which the   |               |                         |
   |           | billing is  |               |                         |
   |           | not valid   |               |                         |
   | endDate   | Date after  | ISO 8601      | "1977-04-22T06:00:00Z"  |
   |           | which the   |               |                         |
   |           | billing is  |               |                         |
   |           | not valid   |               |                         |
   | domains   | FQDNs whose | array(string) | ["deezer.com","spotify. |
   |           | the billing |               | com"]                   |
   |           | is limited  |               |                         |
   | prefixes4 | IPv4        | array(string) | ["78.40.123.182/32","78 |
   |           | prefixes    |               | .40.123.183/32"]        |
   |           | whose the   |               |                         |
   |           | billing is  |               |                         |
   |           | limited     |               |                         |
   | prefixes6 | IPv6        | array(string) | ["2a00:1450:4007:80e::2 |
   |           | prefixes    |               | 00e/64"]                |
   |           | whose the   |               |                         |
   |           | billing is  |               |                         |
   |           | limited     |               |                         |
   +-----------+-------------+---------------+-------------------------+

B.2.  Price

   Here are the different possibilities for the cost of an elementary
   billing.  A missing key means "all/unlimited/unrestricted".  If the
   elementary billing selected has a trafficRemaining of 0 kb, then it
   means that the user has no access to the network.  Actually, if the
   last elementary billing has a trafficRemaining parameter, it means
   that when the user will reach the threshold, he/she will not have
   access to the network anymore.











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   +------------------+------------------+--------------+--------------+
   | Key              | Description      | Type         | JSON Example |
   +------------------+------------------+--------------+--------------+
   | pricePerGb       | The price per    | float        | 2            |
   |                  | Gigabit          | (currency    |              |
   |                  |                  | per Gb)      |              |
   | currency         | The currency     | ISO 4217     | "EUR"        |
   |                  | used             |              |              |
   | throughputMax    | The maximum      | float (kb/s) | 100000       |
   |                  | achievable       |              |              |
   |                  | throughput       |              |              |
   | trafficRemaining | The traffic      | float (kB)   | 12000000     |
   |                  | remaining        |              |              |
   +------------------+------------------+--------------+--------------+

B.3.  Examples

   Example for a user with 20 GB per month for 40 EUR, then reach a
   threshold, and with unlimited data during weekends and to
   example.com:

   [
     {
       "domains": ["example.com"]
     },
     {
       "prefixes4": ["78.40.123.182/32","78.40.123.183/32"]
     },
     {
       "beginDate": "2016-07-16T00:00:00Z",
       "endDate": "2016-07-17T23:59:59Z",
     },
     {
       "beginDate": "2016-06-20T00:00:00Z",
       "endDate": "2016-07-19T23:59:59Z",
       "trafficRemaining": 12000000
     },
     {
       "throughputMax": 100000
     }
   ]

   If the host tries to download data from example.com, the conditions
   of the first elementary billing are fulfilled, so the host takes this
   elementary billing, finds no cost indication in it and so deduces
   that it is totally free.  If the host tries to exchange data with
   foobar.com and the date is 2016-07-14T19:00:00Z, the conditions of
   the first, second and third elementary billing are not fulfilled.



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   But the conditions of the fourth are.  So the host takes this
   elementary billing and sees that there is a threshold, 12 GB are
   remaining.

   Another example for a user abroad, who has 3 GB per year abroad, and
   then pay each MB:

   [
     {
       "beginDate": "2016-02-10T00:00:00Z",
       "endDate": "2017-02-09T23:59:59Z",
       "trafficRemaining": 3000000
     },
     {
       "pricePerGb": 30,
       "currency": "EUR"
     }
   ]

Authors' Addresses

   Pierre Pfister (editor)
   Cisco
   11 Rue Camille Desmoulins
   Issy-les-Moulineaux  92130
   France

   Email: ppfister@cisco.com


   David Schinazi
   Apple

   Email: dschinazi@apple.com


   Tommy Pauly
   Apple

   Email: tpauly@apple.com











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   Eric Vyncke
   Cisco
   De Kleetlaan, 6
   Diegem  1831
   Belgium

   Email: evyncke@cisco.com


   Basile Bruneau
   Ecole Polytechnique
   Vannes  56000
   France

   Email: basile.bruneau@polytechnique.edu




































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