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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: February 24, 2021 J-S. Youn 6 Dongeui Univ 7 D-K. Kim 8 KNU 9 J-H. Choi 10 Samsung Electronics Co., 11 August 23, 2020 13 Transmission of IPv6 Packets over Near Field Communication 14 draft-ietf-6lo-nfc-17 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 February 24, 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 Stack 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 Stack . . . . . . . . . . . . . . . . . . . . . 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 Network 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 allows two NFC-enabled 142 devices to communicate with each other to exchange information 143 bidirectionally. The other two modes do not support two-way 144 communications between two devices. Therefore, the peer-to-peer mode 145 is used for IPv6 over NFC. 147 3.2. Protocol Stack of NFC 149 NFC defines a protocol stack for the peer-to-peer mode (Figure 1). 150 The peer-to-peer mode is offered by the Activities Digital Protocol 151 at the NFC Physical Layer. The NFC Logical Link Layer comprises the 152 Logical Link Control Protocol (LLCP), and when IPv6 is used over NFC, 153 it also includes an IPv6-LLCP Binding. IPv6 and its underlying 154 adaptation Layer (i.e., IPv6-over-NFC adaptation layer) are placed 155 directly on the top of the IPv6-LLCP Binding. An IPv6 datagram is 156 transmitted by the Logical Link Control Protocol (LLCP) with 157 reliable, two-way transmission of information between the peer 158 devices. 160 +----------------------------------------+ - - - - - - - - - 161 | IPv6 - LLCP | . 162 | Binding | . 163 +----------------------------------------+ NFC 164 | | Logical Link 165 | Logical Link Control Protocol | Layer 166 | (LLCP) | . 167 | | . 168 +----------------------------------------+ - - - - - - - - - 169 | | . 170 | Activities | . 171 | Digital Protocol | . 172 | | NFC Physical 173 +----------------------------------------+ Layer 174 | | . 175 | RF Analog | . 176 | | . 177 +----------------------------------------+ - - - - - - - - - 179 Figure 1: Protocol Stack of NFC 181 The LLCP consists of Logical Link Control (LLC) and MAC Mapping. The 182 MAC Mapping integrates an existing RF protocol into the LLCP 183 architecture. The LLC contains three components, such as Link 184 Management, Connection-oriented Transmission, and Connectionless 185 Transmission. The Link Management component is responsible for 186 serializing all connection-oriented and connectionless LLC PDU 187 (Protocol Data Unit) exchanges and for aggregation and disaggregation 188 of small PDUs. The Connection-oriented Transmission component is 189 responsible for maintaining all connection-oriented data exchanges 190 including connection set-up and termination. The Connectionless 191 Transmission component is responsible for handling unacknowledged 192 data exchanges. 194 In order to send an IPv6 packet over NFC, the packet MUST be passed 195 down to the LLCP layer of NFC and carried by an Information Field in 196 an LLCP Protocol Data Unit (I PDU). The LLCP does not support 197 fragmentation and reassembly. For IPv6 addressing or address 198 configuration, the LLCP MUST provide related information, such as 199 link layer addresses, to its upper layer. The LLCP to IPv6 protocol 200 binding MUST transfer the Source Service Access Point (SSAP) and 201 Destination Service Access Point (DSAP) value to the IPv6 over NFC 202 protocol. SSAP is a Logical Link Control (LLC) address of the source 203 NFC-enabled device with a size of 6 bits, while DSAP means an LLC 204 address of the destination NFC-enabled device. Thus, SSAP is a 205 source address, and DSAP is a destination address. 207 3.3. NFC-enabled Device Addressing 209 According to NFC LLCP v1.3 [LLCP-1.3], NFC-enabled devices have two 210 types of 6-bit addresses (i.e., SSAP and DSAP) to identify service 211 access points. Several service access points can be installed on a 212 NFC device. However, the SSAP and DSAP can be used as identifiers 213 for NFC link connections with the IPv6 over NFC adaptation layer. 214 Therefore, the SSAP can be used to generate an IPv6 interface 215 identifier. Address values between 00h and 0Fh of SSAP and DSAP are 216 reserved for identifying the well-known service access points, which 217 are defined in the NFC Forum Assigned Numbers Register. Address 218 values between 10h and 1Fh are assigned by the local LLC to services 219 registered by local service environment. In addition, address values 220 between 20h and 3Fh are assigned by the local LLC as a result of an 221 upper layer service request. Therefore, the address values between 222 20h and 3Fh can be used for generating IPv6 interface identifiers. 224 3.4. MTU of NFC Link Layer 226 As mentioned in Section 3.2, when an IPv6 packet is transmitted, the 227 packet MUST be passed down to LLCP of NFC and transported to an I PDU 228 of LLCP of the NFC-enabled peer device. 230 The information field of an I PDU contains a single service data 231 unit. The maximum number of octets in the information field is 232 determined by the Maximum Information Unit (MIU) for the data link 233 connection. The default value of the MIU for I PDUs is 128 octets. 234 The local and remote LLCs each establish and maintain distinct MIU 235 values for each data link connection endpoint. Also, an LLC may 236 announce a larger MIU for a data link connection by transmitting an 237 optional Maximum Information Unit Extension (MIUX) parameter within 238 the information field. If no MIUX parameter is transmitted, the MIU 239 value is 128 bytes. Otherwise, the MTU size in NFC LLCP MUST be 240 calculated from the MIU value as follows: 242 MTU = MIU = 128 + MIUX. 244 According to [LLCP-1.3], Figure 2 shows an example of the MIUX 245 parameter TLV. The Type and Length fields of the MIUX parameter TLV 246 have each a size of 1 byte. The size of the TLV Value field is 2 247 bytes. 249 0 0 1 2 3 250 0 8 6 2 1 251 +----------+----------+------+-----------+ 252 | Type | Length | Value | 253 +----------+----------+------+-----------+ 254 | 00000010 | 00000010 | 1011 | 0x0~0x7FF | 255 +----------+----------+------+-----------+ 257 Figure 2: Example of MIUX Parameter TLV 259 When the MIUX parameter is used, the TLV Type field MUST be 0x02 and 260 the TLV Length field MUST be 0x02. The MIUX parameter MUST be 261 encoded into the least significant 11 bits of the TLV Value field. 262 The unused bits in the TLV Value field MUST be set to zero by the 263 sender and ignored by the receiver. The maximum possible value of 264 the TLV Value field is 0x7FF, and the maximum size of the LLCP MTU is 265 2175 bytes. The MIUX value MUST be 0x480 to support the IPv6 MTU 266 requirement (of 1280 bytes). 268 4. Specification of IPv6 over NFC 270 NFC technology has requirements owing to low power consumption and 271 allowed protocol overhead. 6LoWPAN standards [RFC4944], [RFC6775], 272 and [RFC6282] provide useful functionality for reducing the overhead 273 of IPv6 over NFC. This functionality consists of link-local IPv6 274 addresses and stateless IPv6 address auto-configuration (see 275 Section 4.2 and Section 4.3), Neighbor Discovery (see Section 4.4) 276 and header compression (see Section 4.6). 278 4.1. Protocol Stack 280 Figure 3 illustrates the IPv6 over NFC protocol stack. Upper layer 281 protocols can be transport layer protocols (e.g., TCP and UDP), 282 application layer protocols, and others capable of running on top of 283 IPv6. 285 +----------------------------------------+ 286 | Upper Layer Protocols | 287 +----------------------------------------+ 288 | IPv6 | 289 +----------------------------------------+ 290 | Adaptation Layer for IPv6 over NFC | 291 +----------------------------------------+ 292 | NFC Logical Link Layer | 293 +----------------------------------------+ 294 | NFC Physical Layer | 295 +----------------------------------------+ 297 Figure 3: Protocol Stack for IPv6 over NFC 299 The adaptation layer for IPv6 over NFC supports neighbor discovery, 300 stateless address auto-configuration, header compression, and 301 fragmentation & reassembly, based on 6LoWPAN. 303 4.2. Stateless Address Autoconfiguration 305 An NFC-enabled device performs stateless address autoconfiguration as 306 per [RFC4862]. A 64-bit Interface identifier (IID) for an NFC 307 interface is formed by utilizing the 6-bit NFC SSAP (see 308 Section 3.3). In the viewpoint of address configuration, such an IID 309 should guarantee a stable IPv6 address during the course of a single 310 connection, because each data link connection is uniquely identified 311 by the pair of DSAP and SSAP included in the header of each LLC PDU 312 in NFC. 314 Following the guidance of [RFC7136], interface identifiers of all 315 unicast addresses for NFC-enabled devices are 64 bits long and 316 constructed by using the generation algorithm of random (but stable) 317 identifier (RID) [RFC7217] (see Figure 4). 319 0 1 3 4 6 320 0 6 2 8 3 321 +---------+---------+---------+---------+ 322 | Random (but stable) Identifier (RID) | 323 +---------+---------+---------+---------+ 325 Figure 4: IID from NFC-enabled device 327 The RID is an output which is created by the F() algorithm with input 328 parameters. One of the parameters is Net_Iface, and NFC Link Layer 329 address (i.e., SSAP) is a source of the Net_Iface parameter. The 330 6-bit address of SSAP of NFC is short and easy to be targeted by 331 attacks of third party (e.g., address scanning). The F() algorithm 332 can provide secured and stable IIDs for NFC-enabled devices. In 333 addition, an optional parameter, Network_ID is used to increase the 334 randomness of the generated IID. 336 4.3. IPv6 Link-Local Address 338 The IPv6 link-local address for an NFC-enabled device is formed by 339 appending the IID to the prefix FE80::/64, as depicted in Figure 5. 341 0 0 0 1 342 0 1 6 2 343 0 0 4 7 344 +----------+------------------+----------------------------+ 345 |1111111010| zeros | Interface Identifier | 346 +----------+------------------+----------------------------+ 347 . . 348 . <- - - - - - - - - - - 128 bits - - - - - - - - - - - -> . 349 . . 351 Figure 5: IPv6 link-local address in NFC 353 A 6LBR may obtain an IPv6 prefix for numbering the NFC network via 354 DHCPv6 Prefix Delegation ([RFC3633]). The "Interface Identifier" can 355 be a secured and stable IID. 357 4.4. Neighbor Discovery 359 Neighbor Discovery Optimization for 6LoWPANs ([RFC6775]) describes 360 the neighbor discovery approach in several 6LoWPAN topologies, such 361 as mesh topology. NFC supports mesh topologies but most of all 362 applications would use a simple multi-hop network topology or 363 directly connected peer-to-peer network because NFC RF range is very 364 short. 366 o When an NFC-enabled 6LN is directly connected to an NFC-enabled 367 6LBR, the NFC 6LN MUST register its address with the 6LBR by 368 sending a Neighbor Solicitation (NS) message with the Extended 369 Address Registration Option (EARO) [RFC8505], and process the 370 Neighbor Advertisement (NA) accordingly. In addition, when the 371 6LN and 6LBR are directly connected, DHCPv6 is used for address 372 assignment. Therefore, Duplicate Address Detection (DAD) is not 373 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. Two NFC devices might still talk to each other (point-to- 379 point topology), but one of them may be connected to the Internet. 380 In a case of multi-hop topology, devices which have two or more 381 connections with neighbor devices, may act as routers. In a case 382 that they meet within a single hop and they have the same 383 properties, any of them can be a router. 385 o For sending Router Solicitations and processing Router 386 Advertisements, the NFC 6LNs MUST follow Sections 5.3 and 5.4 of 387 [RFC6775]. 389 o When a NFC device is a 6LR or a 6LBR, the NFC device MUST follow 390 Section 6 and 7 of [RFC6775]. 392 4.5. Dispatch Header 394 All IPv6-over-NFC encapsulated datagrams are prefixed by an 395 encapsulation header stack consisting of a Dispatch value. The only 396 sequence currently defined for IPv6-over-NFC is the LOWPAN_IPHC 397 compressed IPv6 header (see Section 4.6) header followed by payload, 398 as depicted in Figure 6. 400 +---------------+---------------+--------------+ 401 | IPHC Dispatch | IPHC Header | Payload | 402 +---------------+---------------+--------------+ 404 Figure 6: A IPv6-over-NFC Encapsulated 6LOWPAN_IPHC Compressed IPv6 405 Datagram 407 The dispatch value is treated as an unstructured namespace. Only a 408 single pattern is used to represent current IPv6-over-NFC 409 functionality. 411 +------------+--------------------+-----------+ 412 | Pattern | Header Type | Reference | 413 +------------+--------------------+-----------+ 414 | 01 1xxxxx | 6LOWPAN_IPHC | [RFC6282] | 415 +------------+--------------------+-----------+ 417 Figure 7: Dispatch Values 419 Other IANA-assigned 6LoWPAN Dispatch values do not apply to this 420 specification. 422 4.6. Header Compression 424 Header compression as defined in [RFC6282], which specifies the 425 compression format for IPv6 datagrams on top of IEEE 802.15.4, is 426 REQUIRED in this document as the basis for IPv6 header compression on 427 top of NFC. All headers MUST be compressed according to RFC 6282 428 encoding formats. 430 Therefore, IPv6 header compression in [RFC6282] MUST be implemented. 431 Further, implementations MUST also support Generic Header Compression 432 (GHC) of [RFC7400]. 434 If a 16-bit address is required as a short address, it MUST be formed 435 by padding the 6-bit NFC link-layer (node) address to the left with 436 zeros as shown in Figure 8. 438 0 1 439 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 440 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 441 | Padding(all zeros)| NFC Addr. | 442 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 444 Figure 8: NFC short address format 446 4.7. Fragmentation and Reassembly Considerations 448 IIPv6-over-NFC MUST NOT use fragmentation and reassembly (FAR) at the 449 adaptation layer for the payloads as discussed in Section 3.4. The 450 NFC link connection for IPv6 over NFC MUST be configured with an 451 equivalent MIU size to support the IPv6 MTU requirement (of 1280 452 bytes). To this end, the MIUX value is 0x480. 454 4.8. Unicast and Multicast Address Mapping 456 The address resolution procedure for mapping IPv6 non-multicast 457 addresses into NFC link-layer addresses follows the general 458 description in Section 4.6.1 and 7.2 of [RFC4861], unless otherwise 459 specified. 461 The Source/Target link-layer Address option has the following form 462 when the addresses are 6-bit NFC link-layer (node) addresses. 464 0 1 465 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 466 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 467 | Type | Length=1 | 468 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 469 | | 470 +- Padding (all zeros) -+ 471 | | 472 +- +-+-+-+-+-+-+ 473 | | NFC Addr. | 474 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 476 Figure 9: Unicast address mapping 478 Option fields: 480 Type: 482 1: for Source Link-layer address. 484 2: for Target Link-layer address. 486 Length: 488 This is the length of this option (including the type and 489 length fields) in units of 8 octets. The value of this field 490 is 1 for 6-bit NFC node addresses. 492 NFC address: 494 The 6-bit address in canonical bit order. This is the unicast 495 address the interface currently responds to. 497 The NFC Link Layer does not support multicast. Therefore, packets 498 are always transmitted by unicast between two NFC-enabled devices. 499 Even in the case where a 6LBR is attached to multiple 6LNs, the 6LBR 500 cannot do a multicast to all the connected 6LNs. If the 6LBR needs 501 to send a multicast packet to all its 6LNs, it has to replicate the 502 packet and unicast it on each link. 504 5. Internet Connectivity Scenarios 506 NFC networks can either be isolated or connected to the Internet. 507 The NFC link between two communicating devices is considered to be a 508 point-to-point link only. An NFC link does not support a star 509 topology or mesh network topology but only direct connections between 510 two devices. The NFC link layer does not support packet forwarding 511 at link layer. 513 5.1. NFC-enabled Device Network Connected to the Internet 515 Figure 10 illustrates an example of an NFC-enabled device network 516 connected to the Internet. The distance between 6LN and 6LBR is 517 typically 10 cm or less. For example, a laptop computer that is 518 connected to the Internet (e.g. via Wi-Fi, Ethernet, etc.) may also 519 support NFC and act as a 6LBR. Another NFC-enabled device may run as 520 a 6LN and communicate with the 6LBR, as long as both are within each 521 other's range. 523 NFC link 524 6LN ------------------- 6LBR -------( Internet )--------- CN 525 . . . 526 . <- - - - Subnet - - -> . < - - - IPv6 connection - - -> . 527 . . to the Internet . 529 Figure 10: NFC-enabled device network connected to the Internet 531 Two or more 6LNs may be connected with a 6LBR, but each connection 532 uses a different subnet. The 6LBR is acting as a router and 533 forwarding packets between 6LNs and the Internet. Also, the 6LBR 534 MUST ensure address collisions do not occur and forwards packets sent 535 by one 6LN to another. 537 5.2. Isolated NFC-enabled Device Network 539 In some scenarios, the NFC-enabled device network may permanently be 540 a simple isolated network as shown in the Figure 11. 542 6LN 6LN - - - - - 543 | | . 544 NFC link - >| NFC link - >| . 545 | | . 546 6LN ---------------------- 6LR ---------------------- 6LR Subnet 547 . NFC link NFC link | . 548 . | . 549 . NFC link - >| . 550 . 6LN - - - - - 551 . . 552 . < - - - - - - - - - - Subnet - - - - - - - - - - > . 554 Figure 11: Isolated NFC-enabled device network 556 6. IANA Considerations 558 There are no IANA considerations related to this document. 560 7. Security Considerations 562 NFC is often considered to offer intrinsic security properties due to 563 its short link range. When interface identifiers (IIDs) are 564 generated, devices and users are required to consider mitigating 565 various threats, such as correlation of activities over time, 566 location tracking, device-specific vulnerability exploitation, and 567 address scanning. 569 IPv6-over-NFC uses an IPv6 interface identifier formed from a "short 570 address" and a set of well-known constant bits for the modified 571 EUI-64 format. However, NFC applications use short-lived 572 connections, and a different address is used for each connection, 573 where the latter is of extremely short duration. 575 8. Acknowledgements 577 We are grateful to the members of the IETF 6lo working group. 579 Michael Richardson, Suresh Krishnan, Pascal Thubert, Carsten Bormann, 580 Alexandru Petrescu, James Woodyatt, Dave Thaler, Samita Chakrabarti, 581 Gabriel Montenegro and Carles Gomez Montenegro have provided valuable 582 feedback for this document. 584 9. Normative References 586 [ECMA-340] 587 "Near Field Communication - Interface and Protocol (NFCIP- 588 1) 3rd Ed.", ECMA-340 , June 2013. 590 [LLCP-1.3] 591 "NFC Logical Link Control Protocol version 1.3", NFC Forum 592 Technical Specification , March 2016. 594 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 595 Requirement Levels", BCP 14, RFC 2119, 596 DOI 10.17487/RFC2119, March 1997, 597 . 599 [RFC3633] Troan, O. and R. Droms, "IPv6 Prefix Options for Dynamic 600 Host Configuration Protocol (DHCP) version 6", RFC 3633, 601 DOI 10.17487/RFC3633, December 2003, 602 . 604 [RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman, 605 "Neighbor Discovery for IP version 6 (IPv6)", RFC 4861, 606 DOI 10.17487/RFC4861, September 2007, 607 . 609 [RFC4862] Thomson, S., Narten, T., and T. Jinmei, "IPv6 Stateless 610 Address Autoconfiguration", RFC 4862, 611 DOI 10.17487/RFC4862, September 2007, 612 . 614 [RFC4944] Montenegro, G., Kushalnagar, N., Hui, J., and D. Culler, 615 "Transmission of IPv6 Packets over IEEE 802.15.4 616 Networks", RFC 4944, DOI 10.17487/RFC4944, September 2007, 617 . 619 [RFC6282] Hui, J., Ed. and P. Thubert, "Compression Format for IPv6 620 Datagrams over IEEE 802.15.4-Based Networks", RFC 6282, 621 DOI 10.17487/RFC6282, September 2011, 622 . 624 [RFC6775] Shelby, Z., Ed., Chakrabarti, S., Nordmark, E., and C. 625 Bormann, "Neighbor Discovery Optimization for IPv6 over 626 Low-Power Wireless Personal Area Networks (6LoWPANs)", 627 RFC 6775, DOI 10.17487/RFC6775, November 2012, 628 . 630 [RFC7136] Carpenter, B. and S. Jiang, "Significance of IPv6 631 Interface Identifiers", RFC 7136, DOI 10.17487/RFC7136, 632 February 2014, . 634 [RFC7217] Gont, F., "A Method for Generating Semantically Opaque 635 Interface Identifiers with IPv6 Stateless Address 636 Autoconfiguration (SLAAC)", RFC 7217, 637 DOI 10.17487/RFC7217, April 2014, 638 . 640 [RFC7400] Bormann, C., "6LoWPAN-GHC: Generic Header Compression for 641 IPv6 over Low-Power Wireless Personal Area Networks 642 (6LoWPANs)", RFC 7400, DOI 10.17487/RFC7400, November 643 2014, . 645 [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 646 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, 647 May 2017, . 649 [RFC8505] Thubert, P., Ed., Nordmark, E., Chakrabarti, S., and C. 650 Perkins, "Registration Extensions for IPv6 over Low-Power 651 Wireless Personal Area Network (6LoWPAN) Neighbor 652 Discovery", RFC 8505, DOI 10.17487/RFC8505, November 2018, 653 . 655 Authors' Addresses 656 Younghwan Choi (editor) 657 Electronics and Telecommunications Research Institute 658 218 Gajeongno, Yuseung-gu 659 Daejeon 34129 660 Korea 662 Phone: +82 42 860 1429 663 Email: yhc@etri.re.kr 665 Yong-Geun Hong 666 Electronics and Telecommunications Research Institute 667 161 Gajeong-Dong Yuseung-gu 668 Daejeon 305-700 669 Korea 671 Phone: +82 42 860 6557 672 Email: yghong@etri.re.kr 674 Joo-Sang Youn 675 DONG-EUI University 676 176 Eomgwangno Busan_jin_gu 677 Busan 614-714 678 Korea 680 Phone: +82 51 890 1993 681 Email: joosang.youn@gmail.com 683 Dongkyun Kim 684 Kyungpook National University 685 80 Daehak-ro, Buk-gu 686 Daegu 702-701 687 Korea 689 Phone: +82 53 950 7571 690 Email: dongkyun@knu.ac.kr 692 JinHyouk Choi 693 Samsung Electronics Co., 694 129 Samsung-ro, Youngdong-gu 695 Suwon 447-712 696 Korea 698 Phone: +82 2 2254 0114 699 Email: jinchoe@samsung.com