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Transmission of IPv6 Packets over Near Field Communication

The information below is for an old version of the document that is already published as an RFC.
Document Type
This is an older version of an Internet-Draft that was ultimately published as RFC 9428.
Authors Younghwan Choi , Yong-Geun Hong , Joo-Sang Youn
Last updated 2023-07-20 (Latest revision 2023-03-06)
Replaces draft-hong-6lo-ipv6-over-nfc
RFC stream Internet Engineering Task Force (IETF)
Intended RFC status Proposed Standard
Additional resources Mailing list discussion
Stream WG state Submitted to IESG for Publication
Document shepherd Carles Gomez
Shepherd write-up Show Last changed 2022-11-05
IESG IESG state Became RFC 9428 (Proposed Standard)
Action Holders
Consensus boilerplate Yes
Telechat date (None)
Responsible AD Erik Kline
Send notices to Samita Chakrabarti <>, Carles Gomez <>
IANA IANA review state Version Changed - Review Needed
IANA action state No IANA Actions
6Lo Working Group                                           Y. Choi, Ed.
Internet-Draft                                                      ETRI
Intended status: Standards Track                               Y-G. Hong
Expires: 7 September 2023                                    Daejon Univ
                                                               J-S. Youn
                                                            Dongeui Univ
                                                            6 March 2023

       Transmission of IPv6 Packets over Near Field Communication


   Near Field Communication (NFC) is a set of standards for smartphones
   and portable devices to establish radio communication with each other
   by touching them together or bringing them into proximity, usually no
   more than 10 cm apart.  NFC standards cover communications protocols
   and data exchange formats, and are based on existing radio-frequency
   identification (RFID) standards including ISO/IEC 14443 and FeliCa.
   The standards include ISO/IEC 18092 and those defined by the NFC
   Forum.  The NFC technology has been widely implemented and available
   in mobile phones, laptop computers, and many other devices.  This
   document describes how IPv6 is transmitted over NFC using 6LoWPAN

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

   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 7 September 2023.

Copyright Notice

   Copyright (c) 2023 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

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   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents (
   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 Revised BSD License text as
   described in Section 4.e of the Trust Legal Provisions and are
   provided without warranty as described in the Revised BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Conventions and Terminology . . . . . . . . . . . . . . . . .   3
   3.  Overview of Near Field Communication Technology . . . . . . .   4
     3.1.  Peer-to-peer Mode of NFC  . . . . . . . . . . . . . . . .   4
     3.2.  Protocol Stack of NFC . . . . . . . . . . . . . . . . . .   4
     3.3.  NFC-enabled Device Addressing . . . . . . . . . . . . . .   6
     3.4.  MTU of NFC Link Layer . . . . . . . . . . . . . . . . . .   6
   4.  Specification of IPv6 over NFC  . . . . . . . . . . . . . . .   7
     4.1.  Protocol Stack  . . . . . . . . . . . . . . . . . . . . .   7
     4.2.  Stateless Address Autoconfiguration . . . . . . . . . . .   8
     4.3.  IPv6 Link-Local Address . . . . . . . . . . . . . . . . .   8
     4.4.  Neighbor Discovery  . . . . . . . . . . . . . . . . . . .   9
     4.5.  Dispatch Header . . . . . . . . . . . . . . . . . . . . .  10
     4.6.  Header Compression  . . . . . . . . . . . . . . . . . . .  10
     4.7.  Fragmentation and Reassembly Considerations . . . . . . .  11
     4.8.  Unicast and Multicast Address Mapping . . . . . . . . . .  11
   5.  Internet Connectivity Scenarios . . . . . . . . . . . . . . .  12
     5.1.  NFC-enabled Device Network Connected to the Internet  . .  12
     5.2.  Isolated NFC-enabled Device Network . . . . . . . . . . .  13
   6.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  13
   7.  Security Considerations . . . . . . . . . . . . . . . . . . .  13
   8.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  14
   9.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  14
     9.1.  Normative References  . . . . . . . . . . . . . . . . . .  14
     9.2.  Informative References  . . . . . . . . . . . . . . . . .  16
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  17

1.  Introduction

   NFC is a set of short-range wireless technologies, typically
   requiring a distance between sender and receiver of 10 cm or less.
   NFC operates at 13.56 MHz, and at rates ranging from 106 kbps to 424
   kbps, as per the ISO/IEC 18000-3 air interface [ECMA-340].  NFC
   builds upon RFID systems by allowing two-way communication between
   endpoints.  NFC always involves an initiator and a target; the
   initiator actively generates an RF field that can power a passive
   target.  This enables NFC targets to take very simple form factors,

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   such as tags, stickers, key fobs, or cards, while avoiding the need
   for batteries.  NFC peer-to-peer communication is possible, provided
   that both devices are powered.

   NFC has its very short transmission range of 10 cm or less, so the
   other hidden NFC devices behind outside the range cannot receive NFC
   signals.  Therefore, NFC often regarded as a secure communications

   In order to benefit from Internet connectivity, it is desirable for
   NFC-enabled devices to support IPv6, considering its large address
   space, along with tools for unattended operation, among other
   advantages.  This document specifies how IPv6 is supported over NFC
   by using IPv6 over Low-power Wireless Personal Area Network (6LoWPAN)
   techniques [RFC4944], [RFC6282], [RFC6775]. 6LoWPAN is suitable,
   considering that it was designed to support IPv6 over IEEE 802.15.4
   networks [IEEE802.15.4], and some of the characteristics of the
   latter are similar to those of NFC.

2.  Conventions and Terminology

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "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.

   This specification requires readers to be familiar with all the terms
   and concepts that are discussed in "IPv6 over Low-Power Wireless
   Personal Area Networks (6LoWPANs): Overview, Assumptions, Problem
   Statement, and Goals" [RFC4919], "Transmission of IPv6 Packets over
   IEEE 802.15.4 Networks" [RFC4944], "Neighbor Discovery Optimization
   for IPv6 over Low-Power Wireless Personal Area Networks (6LoWPANs)

      6LoWPAN Node (6LN):

         A 6LoWPAN node is any host or router participating in a LoWPAN.
         This term is used when referring to situations in which either
         a host or router can play the role described.

      6LoWPAN Router (6LR):

         An intermediate router in the LoWPAN that is able to send and
         receive Router Advertisements (RAs) and Router Solicitations
         (RSs) as well as forward and route IPv6 packets.  6LoWPAN
         routers are present only in route-over topologies.

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      6LoWPAN Border Router (6LBR):

         A border router located at the junction of separate 6LoWPAN
         networks or between a 6LoWPAN network and another IP network.
         There may be one or more 6LBRs at the 6LoWPAN network boundary.
         A 6LBR is the responsible authority for IPv6 prefix propagation
         for the 6LoWPAN network it is serving.  An isolated LoWPAN also
         contains a 6LBR in the network, which provides the prefix(es)
         for the isolated network.

3.  Overview of Near Field Communication Technology

   This section presents an overview of NFC, focusing on the
   characteristics of NFC that are most relevant for supporting IPv6.

   NFC enables simple, two-way, interaction between two devices,
   allowing users to perform contactless transactions, access digital
   content, and connect electronic devices with a single touch.  NFC
   utilizes key elements in existing standards for contactless card
   Technology, such as ISO/IEC 14443 A&B and JIS-X 6319-4.  NFC allows
   devices to share information at a distance up to 10 cm with a maximum
   physical layer bit rate of 424 kbps.

3.1.  Peer-to-peer Mode of NFC

   NFC defines three modes of operation: card emulation, peer-to-peer,
   and reader/writer.  Only the peer-to-peer mode allows two NFC-enabled
   devices to communicate with each other to exchange information
   bidirectionally.  The other two modes do not support two-way
   communications between two devices.  Therefore, the peer-to-peer mode
   MUST used for IPv6 over NFC.

3.2.  Protocol Stack of NFC

   NFC defines a protocol stack for the peer-to-peer mode (Figure 1).
   The peer-to-peer mode is offered by the Activities Digital Protocol
   at the NFC Physical Layer.  The NFC Logical Link Layer comprises the
   Logical Link Control Protocol (LLCP), and when IPv6 is used over NFC,
   it also includes an IPv6-LLCP Binding.  IPv6 and its underlying
   adaptation Layer (i.e., IPv6-over-NFC adaptation layer) are placed
   directly on the top of the IPv6-LLCP Binding.  An IPv6 datagram is
   transmitted by the Logical Link Control Protocol (LLCP) with
   guaranteed delivery, two-way transmission of information between the
   peer devices.

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       +----------------------------------------+ - - - - - - - - -
       |      Logical Link Control Protocol     |   NFC Logical
       |                 (LLCP)                 |   Link Layer
       +----------------------------------------+ - - - - - - - - -
       |               Activities               |
       |            Digital Protocol            |   NFC Physical
       +----------------------------------------+   Layer
       |               RF Analog                |
       +----------------------------------------+ - - - - - - - - -

                      Figure 1: Protocol Stack of NFC

   The LLCP consists of Logical Link Control (LLC) and MAC Mapping.  The
   MAC Mapping integrates an existing RF protocol into the LLCP
   architecture.  The LLC contains three components (Link Management,
   Connection-oriented Transmission, and Connectionless Transmission).
   The Link Management is responsible for serializing all connection-
   oriented and connectionless LLC PDU (Protocol Data Unit) exchanges
   and for aggregation and disaggregation of small PDUs.  The
   Connection-oriented Transmission is responsible for maintaining all
   connection-oriented data exchanges including connection set-up and
   termination.  However, NFC links do not guarantee perfect wireless
   link quality, so some type of delays or variation in delay would be
   expected in any case.  The Connectionless Transmission is responsible
   for handling unacknowledged data exchanges.

   In order to send an IPv6 packet over NFC, the packet MUST be passed
   down to the LLCP layer of NFC and carried by an Information Field in
   an LLCP Protocol Data Unit (I PDU).  The LLCP does not support
   fragmentation and reassembly.  For IPv6 addressing or address
   configuration, the LLCP MUST provide related information, such as
   link layer addresses, to its upper layer.  The LLCP to IPv6 protocol
   binding MUST transfer the Source Service Access Point (SSAP) and
   Destination Service Access Point (DSAP) value to the IPv6 over NFC
   adaptation layer.  SSAP is a Logical Link Control (LLC) address of
   the source NFC-enabled device with a size of 6 bits, while DSAP means
   an LLC address of the destination NFC-enabled device.  Thus, SSAP is
   a source address, and DSAP is a destination address.

   In addition, NFC links and host do not need to consider IP header
   bits for QoS signaling, or utilize these meaningfully.

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3.3.  NFC-enabled Device Addressing

   According to [LLCP-1.4], NFC-enabled devices have two types of 6-bit
   addresses (i.e., SSAP and DSAP) to identify service access points.
   Several service access points can be installed on a NFC device.
   However, the SSAP and DSAP can be used as identifiers for NFC link
   connections with the IPv6 over NFC adaptation layer.  Therefore, the
   SSAP can be used to generate an IPv6 interface identifier.  Address
   values between 00h and 0Fh of SSAP and DSAP are reserved for
   identifying the well-known service access points, which are defined
   in the NFC Forum Assigned Numbers Register.  Address values between
   10h and 1Fh are assigned by the local LLC to services registered by
   local service environment.  In addition, address values between 0x2
   and 0x3f are assigned by the local LLC as a result of an upper layer
   service request.  Therefore, the address values between 0x2 and 0x3f
   can be used for generating IPv6 interface identifiers.

3.4.  MTU of NFC Link Layer

   As mentioned in Section 3.2, when an IPv6 packet is transmitted, the
   packet MUST be passed down to LLCP of NFC and transported to an I PDU
   of LLCP of the NFC-enabled peer device.

   The information field of an I PDU contains a single service data
   unit.  The maximum number of octets in the information field is
   determined by the Maximum Information Unit (MIU) for the data link
   connection.  The default value of the MIU for I PDUs is 128 octets.
   The local and remote LLCs each establish and maintain distinct MIU
   values for each data link connection endpoint.  Also, an LLC may
   announce a larger MIU for a data link connection by transmitting an
   optional Maximum Information Unit Extension (MIUX) parameter within
   the information field.  If no MIUX parameter is transmitted, the MIU
   value is 128 bytes.  Otherwise, the MTU size in NFC LLCP MUST be
   calculated from the MIU value as follows:

                          MTU = MIU = 128 + MIUX.

   According to [LLCP-1.4], Figure 2 shows an example of the MIUX
   parameter TLV.  The Type and Length fields of the MIUX parameter TLV
   have each a size of 1 byte.  The size of the TLV Value field is 2

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                  0          0          1     2         3
                  0          8          6     1         1
                 |   Type   |  Length  |      Value      |
                 |   0x02   |   0x02   | 0x0 |   0x480   |

                  Figure 2: Example of MIUX Parameter TLV

   When the MIUX parameter is used, the TLV Type field is 0x02 and the
   TLV Length field is 0x02.  The MIUX parameter is encoded into the
   least significant 11 bits of the TLV Value field.  The unused bits in
   the TLV Value field is set to zero by the sender and ignored by the
   receiver.  The maximum possible value of the TLV Value field is
   0x7FF, and the maximum size of the LLCP MTU is 2175 bytes.  As per
   the present specification [LLCP-1.4], the MIUX value MUST be 0x480 to
   support the IPv6 MTU requirement (of 1280 bytes) [RFC8200].

4.  Specification of IPv6 over NFC

   NFC technology has requirements owing to low power consumption and
   allowed protocol overhead. 6LoWPAN standards [RFC4944], [RFC6775],
   and [RFC6282] provide useful functionality for reducing the overhead
   of IPv6 over NFC.  This functionality consists of link-local IPv6
   addresses and stateless IPv6 address auto-configuration (see
   Section 4.2 and Section 4.3), Neighbor Discovery (see Section 4.4)
   and header compression (see Section 4.6).

4.1.  Protocol Stack

   Figure 3 illustrates the IPv6 over NFC protocol stack.  Upper layer
   protocols can be transport layer protocols (e.g., TCP and UDP),
   application layer protocols, and others capable of running on top of

                |         Upper Layer Protocols          |
                |                 IPv6                   |
                |   Adaptation Layer for IPv6 over NFC   |
                |          NFC Logical Link Layer        |
                |           NFC Physical Layer           |

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                 Figure 3: Protocol Stack for IPv6 over NFC

   The adaptation layer for IPv6 over NFC supports neighbor discovery,
   stateless address auto-configuration, header compression, and
   fragmentation & reassembly, based on 6LoWPAN.  Note that 6LoWPAN
   Header compression [RFC6282] does not define header compression for
   TCP.  The latter can still be supported over IPv6 over NFC, albeit
   without the performance optimization of header compression.

4.2.  Stateless Address Autoconfiguration

   An NFC-enabled device performs stateless address autoconfiguration as
   per [RFC4862].  A 64-bit Interface identifier (IID) for an NFC
   interface is formed by utilizing the 6-bit NFC SSAP (see
   Section 3.3).  In the viewpoint of address configuration, such an IID
   should guarantee a stable IPv6 address during the course of a single
   connection, because each data link connection is uniquely identified
   by the pair of DSAP and SSAP included in the header of each LLC PDU
   in NFC.

   Following the guidance of [RFC7136], interface identifiers of all
   unicast addresses for NFC-enabled devices are 64 bits long and
   constructed by using the generation algorithm of random (but stable)
   identifier (RID) [RFC7217].

   The RID is an output which is created by the F() algorithm with input
   parameters.  One of the parameters is Net_Iface, and NFC Link Layer
   address (i.e., SSAP) MUST be a source of the Net_Iface parameter.
   The 6-bit address of SSAP of NFC is short and easy to be targeted by
   attacks of third party (e.g., address scanning).  The F() algorithm
   with SHA-256 can provide secured and stable IIDs for NFC-enabled
   devices.  In addition, an optional parameter, Network_ID is used to
   increase the randomness of the generated IID with NFC link layer
   address (i.e., SSAP).  The secret key SHOULD be of at least 128 bits.
   It MUST be initialized to a pseudo-random number [RFC4086].

4.3.  IPv6 Link-Local Address

   The IPv6 link-local address for an NFC-enabled device is formed by
   appending the IID to the prefix fe80::/64, as depicted in Figure 4.

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        0          0                  0                          1
        0          1                  6                          2
        0          0                  4                          7
       |1111111010|       zeros      |    Interface Identifier    |
       .                                                          .
       . <- - - - - - - - - - - 128 bits - - - - - - - - - - - -> .
       .                                                          .

                  Figure 4: IPv6 link-local address in NFC

   The "Interface Identifier" can be a random and stable IID.

4.4.  Neighbor Discovery

   Neighbor Discovery Optimization for 6LoWPANs ([RFC6775]) describes
   the neighbor discovery approach in several 6LoWPAN topologies, such
   as mesh topology.  NFC supports mesh topologies, but most of all
   applications would use a simple multi-hop network topology or
   directly connected peer-to-peer network because NFC RF range is very

   *  When an NFC 6LoWPAN Node (6LN) is directly connected to an 6LBR,
      the 6LN MUST register its address with the 6LBR by sending
      Neighbor Solicitation (NS) with the Extended Address Registration
      Option (EARO) [RFC8505], and Neighbor Advertisement (NA) is
      started.  When the 6LN and 6LBR are linked each other, an address
      is assigned to the 6LN.  In this process, Duplicate Address
      Detection (DAD) is not required.

   *  When two or more NFC LNs are connected to the 6LBR, two cases of
      topologies can be formed.  One is a multi-hop topology, and the
      other is a star topology based on the 6LBR.  In multi-hop
      topology, LNs which have two or more links with neighbor nodes may
      act as routers.  In star topology, any of LNs can be a router.

   *  For receiving Router Solicitations and sending Router
      Advertisements, the NFC 6LNs MUST follow Sections 5.3 and 5.4 of

   *  When a NFC device is a 6LoWPAN Router (6LR) or a 6LBR, the NFC
      device MUST follow Section 6 and 7 of [RFC6775].

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4.5.  Dispatch Header

   All IPv6-over-NFC encapsulated datagrams are prefixed by an
   encapsulation header stack consisting of a Dispatch value
   [IANA-6LoWPAN].  The only sequence currently defined for IPv6-over-
   NFC MUST be the LOWPAN_IPHC compressed IPv6 header (see Section 4.6)
   header followed by payload, as depicted in Figure 5 and Figure 6.

             | IPHC Dispatch |  IPHC Header  |    Payload   |

       Figure 5: A IPv6-over-NFC Encapsulated LOWPAN_IPHC Compressed
                               IPv6 Datagram

   The dispatch value (length: 1 octet) is treated as an unstructured
   namespace.  Only a single pattern is used to represent current IPv6-
   over-NFC functionality.

              |  Pattern   | Header Type        | Reference |
              | 01  1xxxxx | LOWPAN_IPHC        | [RFC6282] |

                         Figure 6: Dispatch Values

   Other IANA-assigned 6LoWPAN Dispatch values do not apply to this

4.6.  Header Compression

   Header compression as defined in [RFC6282], which specifies the
   compression format for IPv6 datagrams on top of IEEE 802.15.4, is
   REQUIRED in this document as the basis for IPv6 header compression on
   top of NFC.  All headers MUST be compressed according to RFC 6282
   encoding formats.

   Therefore, IPv6 header compression in [RFC6282] MUST be implemented.
   Further, implementations MUST also support Generic Header Compression
   (GHC) of [RFC7400].

   If a 16-bit address is required as a short address, it MUST be formed
   by padding the 6-bit NFC SSAP (NFC link-layer node address) to the
   left with zeros as shown in Figure 7.

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                      0                   1
                      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
                     | Padding(all zeros)| NFC Addr. |

                     Figure 7: NFC short address format

4.7.  Fragmentation and Reassembly Considerations

   IPv6-over-NFC MUST NOT use fragmentation and reassembly (FAR) at the
   adaptation layer for the payloads as discussed in Section 3.4.  The
   NFC link connection for IPv6 over NFC MUST be configured with an
   equivalent MIU size to support the IPv6 MTU requirement (of 1280
   bytes).  To this end, the MIUX value is 0x480.

4.8.  Unicast and Multicast Address Mapping

   The address resolution procedure for mapping IPv6 non-multicast
   addresses into NFC link-layer addresses follows the general
   description in Section 4.6.1 and 7.2 of [RFC4861], unless otherwise

   The Source/Target link-layer Address option has the following form
   when the addresses are 6-bit NFC SSAP/DSAP (NFC link-layer node

                      0                   1
                      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
                     |      Type     |   Length=1    |
                     |                               |
                     +-     Padding (all zeros)     -+
                     |                               |
                     +-                  +-+-+-+-+-+-+
                     |                   | NFC Addr. |

                     Figure 8: Unicast address mapping

   Option fields:


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      -  1: for Source Link-layer address.

      -  2: for Target Link-layer address.


      -  This is the length of this option (including the type and
         length fields) in units of 8 bits.  The value of this field is
         1 for 6-bit NFC node addresses.

      NFC address:

      -  The 6-bit address in canonical bit order.  This is the unicast
         address the interface currently responds to.

   The NFC Link Layer does not support multicast.  Therefore, packets
   are always transmitted by unicast between two NFC-enabled devices.
   Even in the case where a 6LBR is attached to multiple 6LNs, the 6LBR
   cannot do a multicast to all the connected 6LNs.  If the 6LBR needs
   to send a multicast packet to all its 6LNs, it has to replicate the
   packet and unicast it on each link.  However, this is not energy-
   efficient, and the central node, which is battery-powered, must take
   particular care of power consumption.  To further conserve power, the
   6LBR MUST keep track of multicast listeners at NFC link-level
   granularity (not at subnet granularity), and it MUST NOT forward
   multicast packets to 6LNs that have not registered as listeners for
   multicast groups the packets belong to.  In the opposite direction, a
   6LN always has to send packets to or through the 6LBR.  Hence, when a
   6LN needs to transmit an IPv6 multicast packet, the 6LN will unicast
   the corresponding NFC packet to the 6LBR.

5.  Internet Connectivity Scenarios

5.1.  NFC-enabled Device Network Connected to the Internet

   Figure 9 illustrates an example of an NFC-enabled device network
   connected to the Internet.  The distance between 6LN and 6LBR is
   typically 10 cm or less.  For example, a laptop computer that is
   connected to the Internet (e.g. via Wi-Fi, Ethernet, etc.) may also
   support NFC and act as a 6LBR.  Another NFC-enabled device may run as
   a 6LN and communicate with the 6LBR, as long as both are within each
   other's range.

                NFC link
       6LN ------------------- 6LBR -------( Internet )--------- CN
        .                        .                                .
        . <- - - - Subnet - - -> . < - - - IPv6 connection - - -> .
        .                        .         to the Internet        .

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       Figure 9: NFC-enabled device network connected to the Internet

   Two or more 6LNs may be connected with a 6LBR, but each connection
   uses different IPv6 prefix.  The 6LBR is acting as a router and
   forwarding packets between 6LNs and the Internet.  Also, the 6LBR
   MUST ensure address collisions do not occur because the 6LNs are
   connected to the 6LBR like a start topology, so the 6LBR checks
   whether IPv6 addresses are duplicate or not, since 6LNs need to
   register their addresses with the 6LBR.

5.2.  Isolated NFC-enabled Device Network

   In some scenarios, the NFC-enabled device network may permanently be
   a simple isolated network as shown in the Figure 10.

                               6LN                        6LN - - - - -
                                |                          |      .
                    NFC link - >|              NFC link - >|      .
                                |                          |      .
    6LN ---------------------- 6LR ---------------------- 6LR   Subnet
     .         NFC link                    NFC link        |      .
     .                                                     |      .
     .                                         NFC link - >|      .
     .                                                    6LN - - - - -
     .                                                     .
     . < - - - - - - - - - -  Subnet - - - - - - - - - - > .

               Figure 10: Isolated NFC-enabled device network

   In multihop (i.e., more complex) topologies, the 6LR can also do the
   same task, but then Duplicate Address Detection (DAD) requires the
   extensions for multihop networks such as the ones in [RFC6775].

6.  IANA Considerations

   There are no IANA considerations related to this document.

7.  Security Considerations

   Neighbor Discovery in unencrypted wireless device networks may be
   susceptible to various threats as described in [RFC3756].

   Per the NFC Logical Link Control Protocol [LLCP-1.4]:

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   *  LLCP of NFC provides protection of user data to ensure
      confidentiality of communications.  The confidentiality mechanism
      involves the encryption of user service data with a secret key
      that has been established during link activation.

   *  LLCP of NFC has two modes (i.e., ad-hoc mode and authenticated
      mode) for secure data transfer.  Ad-hoc secure data transfer can
      be established between two communication parties without any prior
      knowledge of the communication partner.  Ad-hoc secure data
      transfer can be vulnerable to Man-In-The-Middle (MITM) attacks.
      Authenticated secure data transfer provides protection against
      Man-In-The-Middle (MITM) attacks.  In the initial bonding step,
      the two communicating parties store a shared secret along with a
      Bonding Identifier.

   *  For all subsequent interactions, the communicating parties re-use
      the shared secret and compute only the unique encryption key for
      that session.  Secure data transfer is based on the cryptographic
      algorithms defined in the NFC Authentication Protocol [NAP-1.0].

   Furthermore, NFC is considered by many to offer intrinsic security
   properties due to its short link range.  When interface identifiers
   (IIDs) are generated, devices and users are required to consider
   mitigating various threats, such as correlation of activities over
   time, location tracking, device-specific vulnerability exploitation,
   and address scanning.  However, IPv6-over-NFC uses a random (but
   stable) identifier (RID) [RFC7217] as an IPv6 interface identifier,
   and NFC applications use short-lived connections, and a different
   address is used for each connection, where the latter is of extremely
   short duration.

8.  Acknowledgements

   We are grateful to the members of the IETF 6lo working group.

   Michael Richardson, Suresh Krishnan, Pascal Thubert, Carsten Bormann,
   Alexandru Petrescu, James Woodyatt, Dave Thaler, Samita Chakrabarti,
   Gabriel Montenegro, Erik Kline and Carles Gomez Montenegro have
   provided valuable feedback for this document.

9.  References

9.1.  Normative References

   [LLCP-1.4] NFC Forum, "NFC Logical Link Control Protocol, Version
              1.4", NFC Forum Technical Specification , January 2021,

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   [NAP-1.0]  NFC Forum, "NFC Authentication Protocol Candidate
              Technical Specification, Version 1.0", NFC Forum Technical
              Specification , December 2020,

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,

   [RFC4086]  Eastlake 3rd, D., Schiller, J., and S. Crocker,
              "Randomness Requirements for Security", BCP 106, RFC 4086,
              DOI 10.17487/RFC4086, June 2005,

   [RFC4861]  Narten, T., Nordmark, E., Simpson, W., and H. Soliman,
              "Neighbor Discovery for IP version 6 (IPv6)", RFC 4861,
              DOI 10.17487/RFC4861, September 2007,

   [RFC4862]  Thomson, S., Narten, T., and T. Jinmei, "IPv6 Stateless
              Address Autoconfiguration", RFC 4862,
              DOI 10.17487/RFC4862, September 2007,

   [RFC4919]  Kushalnagar, N., Montenegro, G., and C. Schumacher, "IPv6
              over Low-Power Wireless Personal Area Networks (6LoWPANs):
              Overview, Assumptions, Problem Statement, and Goals",
              RFC 4919, DOI 10.17487/RFC4919, August 2007,

   [RFC4944]  Montenegro, G., Kushalnagar, N., Hui, J., and D. Culler,
              "Transmission of IPv6 Packets over IEEE 802.15.4
              Networks", RFC 4944, DOI 10.17487/RFC4944, September 2007,

   [RFC6282]  Hui, J., Ed. and P. Thubert, "Compression Format for IPv6
              Datagrams over IEEE 802.15.4-Based Networks", RFC 6282,
              DOI 10.17487/RFC6282, September 2011,

   [RFC6775]  Shelby, Z., Ed., Chakrabarti, S., Nordmark, E., and C.
              Bormann, "Neighbor Discovery Optimization for IPv6 over
              Low-Power Wireless Personal Area Networks (6LoWPANs)",
              RFC 6775, DOI 10.17487/RFC6775, November 2012,

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   [RFC7136]  Carpenter, B. and S. Jiang, "Significance of IPv6
              Interface Identifiers", RFC 7136, DOI 10.17487/RFC7136,
              February 2014, <>.

   [RFC7217]  Gont, F., "A Method for Generating Semantically Opaque
              Interface Identifiers with IPv6 Stateless Address
              Autoconfiguration (SLAAC)", RFC 7217,
              DOI 10.17487/RFC7217, April 2014,

   [RFC7400]  Bormann, C., "6LoWPAN-GHC: Generic Header Compression for
              IPv6 over Low-Power Wireless Personal Area Networks
              (6LoWPANs)", RFC 7400, DOI 10.17487/RFC7400, November
              2014, <>.

   [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
              2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
              May 2017, <>.

   [RFC8200]  Deering, S., Hinden, R., and RFC Publisher, "Internet
              Protocol, Version 6 (IPv6) Specification", STD 86,
              RFC 8200, DOI 10.17487/RFC8200, July 2017,

   [RFC8505]  Thubert, P., Ed., Nordmark, E., Chakrabarti, S., and C.
              Perkins, "Registration Extensions for IPv6 over Low-Power
              Wireless Personal Area Network (6LoWPAN) Neighbor
              Discovery", RFC 8505, DOI 10.17487/RFC8505, November 2018,

9.2.  Informative References

   [ECMA-340] "Near Field Communication - Interface and Protocol (NFCIP-
              1) 3rd Ed.", ECMA International , June 2013,

              Internet Assigned Numbers Authority (IANA), "IPv6 Low
              Power Personal Area Network Parameters", 3 December 2021,

              IEEE Computer Society, "IEEE Standard for Low-Rate
              Wireless Networks, IEEE Std. 802.15.4-2020", IEEE , July
              2020, <>.

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   [RFC3756]  Nikander, P., Ed., Kempf, J., and E. Nordmark, "IPv6
              Neighbor Discovery (ND) Trust Models and Threats",
              RFC 3756, DOI 10.17487/RFC3756, May 2004,

Authors' Addresses

   Younghwan Choi (editor)
   Electronics and Telecommunications Research Institute
   218 Gajeongno, Yuseung-gu
   South Korea
   Phone: +82 42 860 1429

   Yong-Geun Hong
   Daejon University
   62 Daehak-ro, Dong-gu
   South Korea
   Phone: +82 42 280 4841

   Joo-Sang Youn
   DONG-EUI University
   176 Eomgwangno Busan_jin_gu
   South Korea
   Phone: +82 51 890 1993

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