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Checking references for intended status: Proposed Standard ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) -- Possible downref: Non-RFC (?) normative reference: ref. 'ECMA-340' ** Obsolete normative reference: RFC 3633 (Obsoleted by RFC 8415) Summary: 1 error (**), 0 flaws (~~), 1 warning (==), 2 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 6Lo Working Group Y. Choi, Ed. 3 Internet-Draft Y-G. Hong 4 Intended status: Standards Track ETRI 5 Expires: January 10, 2021 J-S. Youn 6 Dongeui Univ 7 D-K. Kim 8 KNU 9 J-H. Choi 10 Samsung Electronics Co., 11 July 9, 2020 13 Transmission of IPv6 Packets over Near Field Communication 14 draft-ietf-6lo-nfc-16 16 Abstract 18 Near Field Communication (NFC) is a set of standards for smartphones 19 and portable devices to establish radio communication with each other 20 by touching them together or bringing them into proximity, usually no 21 more than 10 cm apart. NFC standards cover communications protocols 22 and data exchange formats, and are based on existing radio-frequency 23 identification (RFID) standards including ISO/IEC 14443 and FeliCa. 24 The standards include ISO/IEC 18092 and those defined by the NFC 25 Forum. The NFC technology has been widely implemented and available 26 in mobile phones, laptop computers, and many other devices. This 27 document describes how IPv6 is transmitted over NFC using 6LoWPAN 28 techniques. 30 Status of This Memo 32 This Internet-Draft is submitted in full conformance with the 33 provisions of BCP 78 and BCP 79. 35 Internet-Drafts are working documents of the Internet Engineering 36 Task Force (IETF). Note that other groups may also distribute 37 working documents as Internet-Drafts. The list of current Internet- 38 Drafts is at https://datatracker.ietf.org/drafts/current/. 40 Internet-Drafts are draft documents valid for a maximum of six months 41 and may be updated, replaced, or obsoleted by other documents at any 42 time. It is inappropriate to use Internet-Drafts as reference 43 material or to cite them other than as "work in progress." 45 This Internet-Draft will expire on January 10, 2021. 47 Copyright Notice 49 Copyright (c) 2020 IETF Trust and the persons identified as the 50 document authors. All rights reserved. 52 This document is subject to BCP 78 and the IETF Trust's Legal 53 Provisions Relating to IETF Documents 54 (https://trustee.ietf.org/license-info) in effect on the date of 55 publication of this document. Please review these documents 56 carefully, as they describe your rights and restrictions with respect 57 to this document. Code Components extracted from this document must 58 include Simplified BSD License text as described in Section 4.e of 59 the Trust Legal Provisions and are provided without warranty as 60 described in the Simplified BSD License. 62 Table of Contents 64 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 65 2. Conventions and Terminology . . . . . . . . . . . . . . . . . 3 66 3. Overview of Near Field Communication Technology . . . . . . . 3 67 3.1. Peer-to-peer Mode of NFC . . . . . . . . . . . . . . . . 3 68 3.2. Protocol Stacks of NFC . . . . . . . . . . . . . . . . . 4 69 3.3. NFC-enabled Device Addressing . . . . . . . . . . . . . . 5 70 3.4. MTU of NFC Link Layer . . . . . . . . . . . . . . . . . . 5 71 4. Specification of IPv6 over NFC . . . . . . . . . . . . . . . 6 72 4.1. Protocol Stacks . . . . . . . . . . . . . . . . . . . . . 6 73 4.2. Stateless Address Autoconfiguration . . . . . . . . . . . 7 74 4.3. IPv6 Link-Local Address . . . . . . . . . . . . . . . . . 8 75 4.4. Neighbor Discovery . . . . . . . . . . . . . . . . . . . 8 76 4.5. Dispatch Header . . . . . . . . . . . . . . . . . . . . . 9 77 4.6. Header Compression . . . . . . . . . . . . . . . . . . . 9 78 4.7. Fragmentation and Reassembly Considerations . . . . . . . 10 79 4.8. Unicast and Multicast Address Mapping . . . . . . . . . . 10 80 5. Internet Connectivity Scenarios . . . . . . . . . . . . . . . 11 81 5.1. NFC-enabled Device Connected to the Internet . . . . . . 11 82 5.2. Isolated NFC-enabled Device Network . . . . . . . . . . . 12 83 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12 84 7. Security Considerations . . . . . . . . . . . . . . . . . . . 12 85 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 13 86 9. Normative References . . . . . . . . . . . . . . . . . . . . 13 87 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 14 89 1. Introduction 91 NFC is a set of short-range wireless technologies, typically 92 requiring a distance between sender and receiver of 10 cm or less. 93 NFC operates at 13.56 MHz, and at rates ranging from 106 kbit/s to 94 424 kbit/s, as per the ISO/IEC 18000-3 air interface [ECMA-340]. NFC 95 builds upon RFID systems by allowing two-way communication between 96 endpoints. NFC always involves an initiator and a target; the 97 initiator actively generates an RF field that can power a passive 98 target. This enables NFC targets to take very simple form factors, 99 such as tags, stickers, key fobs, or cards, while avoiding the need 100 for batteries. NFC peer-to-peer communication is possible, provided 101 that both devices are powered. As of the writing, NFC is supported 102 by the main smartphone operating systems. 104 NFC is often regarded as a secure communications technology, due to 105 its very short transmission range. 107 In order to benefit from Internet connectivity, it is desirable for 108 NFC-enabled devices to support IPv6, considering its large address 109 space, along with tools for unattended operation, among other 110 advantages. This document specifies how IPv6 is supported over NFC 111 by using IPv6 over Low-power Wireless Personal Area Network (6LoWPAN) 112 techniques [RFC4944], [RFC6282], [RFC6775]. 6LoWPAN is suitable, 113 considering that it was designed to support IPv6 over IEEE 802.15.4 114 networks, and some of the characteristics of the latter are similar 115 to those of NFC. 117 2. Conventions and Terminology 119 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 120 "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and 121 "OPTIONAL" in this document are to be interpreted as described in BCP 122 14 [RFC2119] [RFC8174] when, and only when, they appear in all 123 capitals, as shown here. 125 3. Overview of Near Field Communication Technology 127 This section presents an overview of NFC, focusing on the 128 characteristics of NFC that are most relevant for supporting IPv6. 130 NFC enables simple, two-way, interaction between two devices, 131 allowing users to perform contactless transactions, access digital 132 content, and connect electronic devices with a single touch. NFC 133 utilizes key elements in existing standards for contactless card 134 Technology, such as ISO/IEC 14443 A&B and JIS-X 6319-4. NFC allows 135 devices to share information at a distance up to 10 cm with a maximum 136 physical layer bit rate of 424 kbps. 138 3.1. Peer-to-peer Mode of NFC 140 NFC defines three modes of operation: card emulation, peer-to-peer, 141 and reader/writer. Only the peer-to-peer mode enables two NFC- 142 enabled devices to communicate with each other to exchange 143 information and share files, so that users of NFC-enabled devices can 144 quickly share contact information and other files with a touch. The 145 other two modes does not support two-way communications between two 146 devices. Therefore, the peer mode is used for ipv6-over-nfc. 148 3.2. Protocol Stacks of NFC 150 NFC defines a protocol stack for the peer-to-peer mode (Figure 1). 151 The peer-to-peer mode is made in Activities Digital Protocol in NFC 152 Physical Lay. The NFC Logical Link consists of Binding for IPv6-LLCP 153 and Logical Link Control Protocol Layer (LLCP). IPv6 and its 154 underlying adaptation Layer (i.e., IPv6-over-NFC adaptation layer) 155 are placed directly on the top of the IPv6-LLCP Binding. An IPv6 156 datagram is transmitted by the Logical Link Control Protocol (LLCP) 157 with reliable, two-way transmission of information between the peer 158 devices. 160 +----------------------------------------+ ------------------ 161 | IPv6-LLCP Binding | | 162 +----------------------------------------+ NFC 163 | | Logical Link 164 | Logical Link Control Protocol | Layer 165 | (LLCP) | | 166 +----------------------------------------+ ------------------ 167 | | | 168 | Activities | | 169 | Digital Protocol | NFC 170 | | Physical 171 +----------------------------------------+ Layer 172 | | | 173 | RF Analog | | 174 | | | 175 +----------------------------------------+ ------------------ 177 Figure 1: Protocol Stack of NFC 179 The LLCP consists of Logical Link Control (LLC) and MAC Mapping. The 180 MAC Mapping integrates an existing RF protocol into the LLCP 181 architecture. The LLC contains three components, such as Link 182 Management, Connection-oriented Transmission, and Connection-less 183 Transmission. The Link Management component is responsible for 184 serializing all connection-oriented and connection-less LLC PDU 185 (Protocol Data Unit) exchanges and for aggregation and disaggregation 186 of small PDUs. The Connection-oriented Transmission component is 187 responsible for maintaining all connection-oriented data exchanges 188 including connection set-up and termination. The Connectionless 189 Transmission component is responsible for handling unacknowledged 190 data exchanges. 192 In order to send an IPv6 packet over NFC, the packet MUST be passed 193 down to the LLCP layer of NFC and carried by an Information (I) or an 194 Unnumbered Information (UI) Field in an LLCP Protocol Data Unit 195 (PDU). LLCP does not support fragmentation and reassembly. For IPv6 196 addressing or address configuration, LLCP MUST provide related 197 information, such as link layer addresses, to its upper layer. The 198 LLCP to IPv6 protocol binding MUST transfer the SSAP and DSAP value 199 to the IPv6 over NFC protocol. SSAP stands for Source Service Access 200 Point, which is a 6-bit value meaning a kind of Logical Link Control 201 (LLC) address, while DSAP means an LLC address of the destination 202 NFC-enabled device. Thus, SSAP is a source address, and DSAP is a 203 destination address. 205 3.3. NFC-enabled Device Addressing 207 According to NFC Logical Link Control Protocol v1.3 [LLCP-1.3], NFC- 208 enabled devices have two types of 6-bit addresses (i.e., SSAP and 209 DSAP) to identify service access points. Several service access 210 points can be installed on a NFC device. However, the SSAP and DSAP 211 can be used as identifiers for NFC link connections with the IPv6 212 over NFC adaptation layer. Therefore, the SSAP can be used to 213 generate an IPv6 interface identifier. Address values between 00h 214 and 0Fh of SSAP and DSAP are reserved for identifying the well-known 215 service access points, which are defined in the NFC Forum Assigned 216 Numbers Register. Address values between 10h and 1Fh are assigned by 217 the local LLC to services registered by local service environment. 218 In addition, address values between 20h and 3Fh are assigned by the 219 local LLC as a result of an upper layer service request. Therefore, 220 the address values between 20h and 3Fh can be used for generating 221 IPv6 interface identifiers. 223 3.4. MTU of NFC Link Layer 225 As mentioned in Section 3.2, when an IPv6 packet is transmitted, the 226 packet MUST be passed down to LLCP of NFC and transported to an 227 Unnumbered Information Protocol Data Unit (UI PDU) and an Information 228 Field in Protocol Data Unit (I PDU) of LLCP of the NFC-enabled peer 229 device. 231 The information field of an I PDU contains a single service data 232 unit. The maximum number of octets in the information field is 233 determined by the Maximum Information Unit (MIU) for the data link 234 connection. The default value of the MIU for I PDUs is 128 octets. 235 The local and remote LLCs each establish and maintain distinct MIU 236 values for each data link connection endpoint. Also, an LLC may 237 announce a larger MIU for a data link connection by transmitting an 238 optional Maximum Information Unit Extension (MIUX) parameter within 239 the information field. If no MIUX parameter is transmitted, the MIU 240 value is 128 bytes. Otherwise, the MTU size in NFC LLCP MUST be 241 calculated from the MIU value as follows: 243 MTU = MIU = 128 + MIUX. 245 According to [LLCP-1.3], Figure 2 shows an example of the MIUX 246 parameter TLV. The Type and Length fields of the MIUX parameter TLV 247 have each a size of 1 byte. The size of the TLV Value field is 2 248 bytes. 250 0 0 1 2 3 251 0 8 6 2 1 252 +----------+----------+------+-----------+ 253 | Type | Length | Value | 254 +----------+----------+------+-----------+ 255 | 00000010 | 00000010 | 1011 | 0x0~0x7FF | 256 +----------+----------+------+-----------+ 258 Figure 2: Example of MIUX Parameter TLV 260 When the MIUX parameter is used, the TLV Type field MUST be 0x02 and 261 the TLV Length field MUST be 0x02. The MIUX parameter MUST be 262 encoded into the least significant 11 bits of the TLV Value field. 263 The unused bits in the TLV Value field MUST be set to zero by the 264 sender and ignored by the receiver. The maximum possible value of 265 the TLV Value field is 0x7FF, and the maximum size of the LLCP MTU is 266 2176 bytes. If fragmentation functionality is not used at the 267 adaptation layer between IPv6 and NFC, the MIUX value MUST be 0x480 268 to support the IPv6 MTU requirement (of 1280 bytes). 270 4. Specification of IPv6 over NFC 272 NFC technology also has considerations and requirements owing to low 273 power consumption and allowed protocol overhead. 6LoWPAN standards 274 [RFC4944], [RFC6775], and [RFC6282] provide useful functionality for 275 reducing overhead which can be applied to NFC. This functionality 276 consists of link-local IPv6 addresses and stateless IPv6 address 277 auto-configuration (see Section 4.2), Neighbor Discovery (see 278 Section 4.4) and header compression (see Section 4.6). 280 4.1. Protocol Stacks 282 Figure 3 illustrates IPv6 over NFC. Upper layer protocols can be 283 transport layer protocols (e.g., TCP and UDP), application layer 284 protocols, and others capable of running on top of IPv6. 286 | | 287 | Upper Layer Protocols | 288 +----------------------------------------+ 289 | IPv6 | 290 +----------------------------------------+ 291 | Adaptation Layer for IPv6 over NFC | 292 +----------------------------------------+ 293 | NFC Link Layer | 294 +----------------------------------------+ 295 | NFC Physical Layer | 296 +----------------------------------------+ 298 Figure 3: Protocol Stack for IPv6 over NFC 300 The adaptation layer for IPv6 over NFC supports neighbor discovery, 301 stateless address auto-configuration, header compression, and 302 fragmentation & reassembly, based on 6LoWPAN. 304 4.2. Stateless Address Autoconfiguration 306 An NFC-enabled device performs stateless address autoconfiguration as 307 per [RFC4862]. A 64-bit Interface identifier (IID) for an NFC 308 interface is formed by utilizing the 6-bit NFC SSAP (see 309 Section 3.3). In the viewpoint of address configuration, such an IID 310 should guarantee a stable IPv6 address during the course of a single 311 connection, because each data link connection is uniquely identified 312 by the pair of DSAP and SSAP included in the header of each LLC PDU 313 in NFC. 315 Following the guidance of [RFC7136], interface identifiers of all 316 unicast addresses for NFC-enabled devices are 64 bits long and 317 constructed by using the generation algorithm of random (but stable) 318 identifier (RID) [RFC7217] (see Figure 4). 320 0 1 3 4 6 321 0 6 2 8 3 322 +---------+---------+---------+---------+ 323 | Random (but stable) Identifier (RID) | 324 +---------+---------+---------+---------+ 326 Figure 4: IID from NFC-enabled device 328 The RID is an output which is created by the algorithm, F() with 329 input parameters. One of the parameters is Net_Iface, and NFC Link 330 Layer address (i.e., SSAP) is a source of the Net_Iface parameter. 331 The 6-bit address of SSAP of NFC is easy and short to be targeted by 332 attacks of third party (e.g., address scanning). The F() can provide 333 secured and stable IIDs for NFC-enabled devices. In addition, an 334 optional parameter, Network_ID is used to increase the randomness of 335 the generated IID. 337 4.3. IPv6 Link-Local Address 339 The IPv6 link-local address for an NFC-enabled device is formed by 340 appending the IID, to the prefix FE80::/64, as depicted in Figure 5. 342 0 0 0 1 343 0 1 6 2 344 0 0 4 7 345 +----------+------------------+----------------------------+ 346 |1111111010| zeros | Interface Identifier | 347 +----------+------------------+----------------------------+ 348 | | 349 | <---------------------- 128 bits ----------------------> | 350 | | 352 Figure 5: IPv6 link-local address in NFC 354 A 6LBR may obtain an IPv6 prefix for numbering the NFC network via 355 DHCPv6 Prefix Delegation ([RFC3633]). The "Interface Identifier" can 356 be a secured and stable IIDs. 358 4.4. Neighbor Discovery 360 Neighbor Discovery Optimization for 6LoWPANs ([RFC6775]) describes 361 the neighbor discovery approach in several 6LoWPAN topologies, such 362 as mesh topology. NFC supports mesh topologies but most of all 363 applications would use a simple multi-hop network topology or 364 directly connected peer-to-peer network because NFC RF range is very 365 short. 367 o When an NFC-enabled 6LN is directly connected to an NFC-enabled 368 6LBR, the NFC 6LN MUST register its address with the 6LBR by 369 sending a Neighbor Solicitation (NS) message with the Address 370 Registration Option (ARO), and process the Neighbor Advertisement 371 (NA) accordingly. In addition, when the 6LN and 6LBR are directly 372 connected, DHCPv6 is used for address assignment. Therefore, 373 Duplicate Address Detection (DAD) is not necessary between them. 375 o When two or more NFC devices are connected, there are two cases. 376 One is that three or more NFC devices are linked with multi-hop 377 connections, and the other is that they meet within a single hop 378 range (e.g., isolated network). In a case of multi-hop topology, 379 devices which have two or more connections with neighbor devices, 380 play a router for 6LR/6LBR. In a case that they meet within a 381 single hop and they have the same properties, any of them can be a 382 router. 384 o For sending Router Solicitations and processing Router 385 Advertisements, the NFC 6LNs MUST follow Sections 5.3 and 5.4 of 386 [RFC6775]. 388 o When a NFC device is a 6LR or a 6LBR, the NFC device MUST follow 389 Section 6 and 7 of [RFC6775]. 391 4.5. Dispatch Header 393 All IPv6-over-NFC encapsulated datagrams are prefixed by an 394 encapsulation header stack consisting of a Dispatch value. The only 395 sequence currently defined for IPv6-over-NFC is the 6LOWPAN_IPHC 396 header followed by payload, as depicted in Figure 6. 398 +---------------+---------------+--------------+ 399 | IPHC Dispatch | IPHC Header | Payload | 400 +---------------+---------------+--------------+ 402 Figure 6: A IPv6-over-NFC Encapsulated 6LOWPAN_IPHC Compressed IPv6 403 Datagram 405 The dispatch value is treated as an unstructured namespace. Only a 406 single pattern is used to represent current IPv6-over-NFC 407 functionality. 409 +------------+--------------------+-----------+ 410 | Pattern | Header Type | Reference | 411 +------------+--------------------+-----------+ 412 | 01 1xxxxx | 6LOWPAN_IPHC | [RFC6282] | 413 +------------+--------------------+-----------+ 415 Figure 7: Dispatch Values 417 Other IANA-assigned 6LoWPAN Dispatch values do not apply to this 418 specification. 420 4.6. Header Compression 422 Header compression as defined in [RFC6282], which specifies the 423 compression format for IPv6 datagrams on top of IEEE 802.15.4, is 424 REQUIRED in this document as the basis for IPv6 header compression on 425 top of NFC. All headers MUST be compressed according to RFC 6282 426 encoding formats. 428 Therefore, IPv6 header compression in [RFC6282] MUST be implemented. 429 Further, implementations MUST also support Generic Header Compression 430 (GHC) of [RFC7400]. 432 If a 16-bit address is required as a short address, it MUST be formed 433 by padding the 6-bit NFC link-layer (node) address to the left with 434 zeros as shown in Figure 8. 436 0 1 437 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 438 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 439 | Padding(all zeros)| NFC Addr. | 440 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 442 Figure 8: NFC short address format 444 4.7. Fragmentation and Reassembly Considerations 446 IPv6-over-NFC SHOULD NOT use fragmentation and reassembly (FAR) for 447 the payloads as discussed in Section 3.4. The NFC link connection 448 for IPv6 over NFC MUST be configured with an equivalent MIU size to 449 fit the MTU of IPv6 Packet. The MIUX value is 0x480 in order to fit 450 the MTU (1280 bytes) of a IPv6 packet if NFC devices support 451 extension of the MTU. 453 4.8. Unicast and Multicast Address Mapping 455 The address resolution procedure for mapping IPv6 non-multicast 456 addresses into NFC link-layer addresses follows the general 457 description in Section 4.6.1 and 7.2 of [RFC4861], unless otherwise 458 specified. 460 The Source/Target link-layer Address option has the following form 461 when the addresses are 6-bit NFC link-layer (node) addresses. 463 0 1 464 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 465 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 466 | Type | Length=1 | 467 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 468 | | 469 +- Padding (all zeros) -+ 470 | | 471 +- +-+-+-+-+-+-+ 472 | | NFC Addr. | 473 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 475 Figure 9: Unicast address mapping 477 Option fields: 479 Type: 481 1: for Source Link-layer address. 483 2: for Target Link-layer address. 485 Length: 487 This is the length of this option (including the type and 488 length fields) in units of 8 octets. The value of this field 489 is 1 for 6-bit NFC node addresses. 491 NFC address: 493 The 6-bit address in canonical bit order. This is the unicast 494 address the interface currently responds to. 496 The NFC Link Layer does not support multicast. Therefore, packets 497 are always transmitted by unicast between two NFC-enabled devices. 498 Even in the case where a 6LBR is attached to multiple 6LNs, the 6LBR 499 cannot do a multicast to all the connected 6LNs. If the 6LBR needs 500 to send a multicast packet to all its 6LNs, it has to replicate the 501 packet and unicast it on each link. 503 5. Internet Connectivity Scenarios 505 NFC networks can either be isolated or connected to the Internet. 506 The NFC link between two communicating devices is considered to be a 507 point-to-point link only. An NFC link does not support a star 508 topology or mesh network topology but only direct connections between 509 two devices. The NFC link layer does not support packet forwarding 510 in link layer. 512 5.1. NFC-enabled Device Connected to the Internet 514 Figure 10 illustrates an example of an NFC-enabled device network 515 connected to the Internet. The distance between 6LN and 6LBR is 516 typically 10 cm or less. If there is any laptop computers close to a 517 user, it will become a 6LBR. Additionally, when the user mounts an 518 NFC-enabled air interface adapter (e.g., portable NFC dongle) on the 519 close laptop PC, the user's NFC-enabled device (6LN) can communicate 520 with the laptop PC (6LBR) within 10 cm distance. 522 ************ 523 6LN ------------------- 6LBR -----* Internet *------- CN 524 | | ************ | 525 | | | 526 | <------ NFC Link -----> | <----- IPv6 packet ------> | 527 | (dis. 10 cm or less) | | 529 Figure 10: NFC-enabled device network connected to the Internet 531 Two or more 6LNs are connected with a 6LBR, but each connection uses 532 a different subnet. The 6LBR is acting as a router and forwarding 533 packets between 6LNs and the Internet. Also, the 6LBR MUST ensure 534 address collisions do not occur and forwards packets sent by one 6LN 535 to another. 537 5.2. Isolated NFC-enabled Device Network 539 In some scenarios, the NFC-enabled device network may transiently be 540 a simple isolated network as shown in the Figure 11. 542 6LN 6LN 543 | | 544 NFC link -> | NFC -> | 545 (dist. 10 cm or less) | (dist. 10 cm or less) | 546 | | 547 6LN ---------------------- 6LR ---------------------- 6LR 548 NFC Link NFC Link 549 (dist. 10 cm or less) (dist. 10 cm or less) 551 Figure 11: Isolated NFC-enabled device network 553 6. IANA Considerations 555 There are no IANA considerations related to this document. 557 7. Security Considerations 559 There are the intrinsic security properties of NFC due to its short 560 link range. When interface identifiers (IIDs) are generated, devices 561 and users are required to consider mitigating various threats, such 562 as correlation of activities over time, location tracking, device- 563 specific vulnerability exploitation, and address scanning. 565 IPv6-over-NFC uses an IPv6 interface identifier formed from a "Short 566 Address" and a set of well-known constant bits for the modified 567 EUI-64 format. However, NFC applications use short-lived 568 connections, and a different address is used for each connection, 569 where the latter is of extremely short duration. 571 8. Acknowledgements 573 We are grateful to the members of the IETF 6lo working group. 575 Michael Richardson, Suresh Krishnan, Pascal Thubert, Carsten Bormann, 576 Alexandru Petrescu, James Woodyatt, Dave Thaler, Samita Chakrabarti, 577 Gabriel Montenegro and Carles Gomez Montenegro have provided valuable 578 feedback for this document. 580 9. Normative References 582 [ECMA-340] 583 "Near Field Communication - Interface and Protocol (NFCIP- 584 1) 3rd Ed.", ECMA-340 , June 2013. 586 [LLCP-1.3] 587 "NFC Logical Link Control Protocol version 1.3", NFC Forum 588 Technical Specification , March 2016. 590 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 591 Requirement Levels", BCP 14, RFC 2119, 592 DOI 10.17487/RFC2119, March 1997, 593 . 595 [RFC3633] Troan, O. and R. Droms, "IPv6 Prefix Options for Dynamic 596 Host Configuration Protocol (DHCP) version 6", RFC 3633, 597 DOI 10.17487/RFC3633, December 2003, 598 . 600 [RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman, 601 "Neighbor Discovery for IP version 6 (IPv6)", RFC 4861, 602 DOI 10.17487/RFC4861, September 2007, 603 . 605 [RFC4862] Thomson, S., Narten, T., and T. Jinmei, "IPv6 Stateless 606 Address Autoconfiguration", RFC 4862, 607 DOI 10.17487/RFC4862, September 2007, 608 . 610 [RFC4944] Montenegro, G., Kushalnagar, N., Hui, J., and D. Culler, 611 "Transmission of IPv6 Packets over IEEE 802.15.4 612 Networks", RFC 4944, DOI 10.17487/RFC4944, September 2007, 613 . 615 [RFC6282] Hui, J., Ed. and P. Thubert, "Compression Format for IPv6 616 Datagrams over IEEE 802.15.4-Based Networks", RFC 6282, 617 DOI 10.17487/RFC6282, September 2011, 618 . 620 [RFC6775] Shelby, Z., Ed., Chakrabarti, S., Nordmark, E., and C. 621 Bormann, "Neighbor Discovery Optimization for IPv6 over 622 Low-Power Wireless Personal Area Networks (6LoWPANs)", 623 RFC 6775, DOI 10.17487/RFC6775, November 2012, 624 . 626 [RFC7136] Carpenter, B. and S. Jiang, "Significance of IPv6 627 Interface Identifiers", RFC 7136, DOI 10.17487/RFC7136, 628 February 2014, . 630 [RFC7217] Gont, F., "A Method for Generating Semantically Opaque 631 Interface Identifiers with IPv6 Stateless Address 632 Autoconfiguration (SLAAC)", RFC 7217, 633 DOI 10.17487/RFC7217, April 2014, 634 . 636 [RFC7400] Bormann, C., "6LoWPAN-GHC: Generic Header Compression for 637 IPv6 over Low-Power Wireless Personal Area Networks 638 (6LoWPANs)", RFC 7400, DOI 10.17487/RFC7400, November 639 2014, . 641 [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 642 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, 643 May 2017, . 645 Authors' Addresses 647 Younghwan Choi (editor) 648 Electronics and Telecommunications Research Institute 649 218 Gajeongno, Yuseung-gu 650 Daejeon 34129 651 Korea 653 Phone: +82 42 860 1429 654 Email: yhc@etri.re.kr 655 Yong-Geun Hong 656 Electronics and Telecommunications Research Institute 657 161 Gajeong-Dong Yuseung-gu 658 Daejeon 305-700 659 Korea 661 Phone: +82 42 860 6557 662 Email: yghong@etri.re.kr 664 Joo-Sang Youn 665 DONG-EUI University 666 176 Eomgwangno Busan_jin_gu 667 Busan 614-714 668 Korea 670 Phone: +82 51 890 1993 671 Email: joosang.youn@gmail.com 673 Dongkyun Kim 674 Kyungpook National University 675 80 Daehak-ro, Buk-gu 676 Daegu 702-701 677 Korea 679 Phone: +82 53 950 7571 680 Email: dongkyun@knu.ac.kr 682 JinHyouk Choi 683 Samsung Electronics Co., 684 129 Samsung-ro, Youngdong-gu 685 Suwon 447-712 686 Korea 688 Phone: +82 2 2254 0114 689 Email: jinchoe@samsung.com