idnits 2.17.1 draft-ietf-roll-trickle-mcast-07.txt: Checking boilerplate required by RFC 5378 and the IETF Trust (see https://trustee.ietf.org/license-info): ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/1id-guidelines.txt: ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/checklist : ---------------------------------------------------------------------------- No issues found here. Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year -- The document date (February 15, 2014) is 3716 days in the past. Is this intentional? Checking references for intended status: Proposed Standard ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) == Missing Reference: '0x01' is mentioned on line 1025, but not defined == Missing Reference: '0xFF' is mentioned on line 1025, but not defined == Outdated reference: A later version (-07) exists of draft-ietf-6man-multicast-scopes-02 ** Obsolete normative reference: RFC 2460 (Obsoleted by RFC 8200) -- Obsolete informational reference (is this intentional?): RFC 4601 (Obsoleted by RFC 7761) Summary: 1 error (**), 0 flaws (~~), 4 warnings (==), 2 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 ROLL J. Hui 3 Internet-Draft Cisco 4 Intended status: Standards Track R. Kelsey 5 Expires: August 19, 2014 Silicon Labs 6 February 15, 2014 8 Multicast Protocol for Low power and Lossy Networks (MPL) 9 draft-ietf-roll-trickle-mcast-07 11 Abstract 13 This document specifies the Multicast Protocol for Low power and 14 Lossy Networks (MPL) that provides IPv6 multicast forwarding in 15 constrained networks. MPL avoids the need to construct or maintain 16 any multicast forwarding topology, disseminating messages to all MPL 17 Forwarders in an MPL Domain. MPL uses the Trickle algorithm to 18 manage message transmissions for both control and data-plane 19 messages. Different Trickle parameter configurations allow MPL to 20 trade between dissemination latency and transmission efficiency. 22 Status of This Memo 24 This Internet-Draft is submitted in full conformance with the 25 provisions of BCP 78 and BCP 79. 27 Internet-Drafts are working documents of the Internet Engineering 28 Task Force (IETF). Note that other groups may also distribute 29 working documents as Internet-Drafts. The list of current Internet- 30 Drafts is at http://datatracker.ietf.org/drafts/current/. 32 Internet-Drafts are draft documents valid for a maximum of six months 33 and may be updated, replaced, or obsoleted by other documents at any 34 time. It is inappropriate to use Internet-Drafts as reference 35 material or to cite them other than as "work in progress." 37 This Internet-Draft will expire on August 19, 2014. 39 Copyright Notice 41 Copyright (c) 2014 IETF Trust and the persons identified as the 42 document authors. All rights reserved. 44 This document is subject to BCP 78 and the IETF Trust's Legal 45 Provisions Relating to IETF Documents 46 (http://trustee.ietf.org/license-info) in effect on the date of 47 publication of this document. Please review these documents 48 carefully, as they describe your rights and restrictions with respect 49 to this document. Code Components extracted from this document must 50 include Simplified BSD License text as described in Section 4.e of 51 the Trust Legal Provisions and are provided without warranty as 52 described in the Simplified BSD License. 54 Table of Contents 56 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 57 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 58 3. Applicability Statement . . . . . . . . . . . . . . . . . . . 4 59 4. Protocol Overview . . . . . . . . . . . . . . . . . . . . . . 5 60 4.1. MPL Domains . . . . . . . . . . . . . . . . . . . . . . . 5 61 4.2. Information Base Overview . . . . . . . . . . . . . . . . 6 62 4.3. Overview . . . . . . . . . . . . . . . . . . . . . . . . 6 63 4.4. Signaling Overview . . . . . . . . . . . . . . . . . . . 8 64 5. MPL Parameters and Constants . . . . . . . . . . . . . . . . 8 65 5.1. MPL Multicast Addresses . . . . . . . . . . . . . . . . . 8 66 5.2. MPL Message Types . . . . . . . . . . . . . . . . . . . . 9 67 5.3. MPL Seed Identifiers . . . . . . . . . . . . . . . . . . 9 68 5.4. MPL Parameters . . . . . . . . . . . . . . . . . . . . . 9 69 6. Protocol Message Formats . . . . . . . . . . . . . . . . . . 11 70 6.1. MPL Option . . . . . . . . . . . . . . . . . . . . . . . 11 71 6.2. MPL Control Message . . . . . . . . . . . . . . . . . . . 12 72 6.3. MPL Seed Info . . . . . . . . . . . . . . . . . . . . . . 13 73 7. Information Base . . . . . . . . . . . . . . . . . . . . . . 14 74 7.1. Local Interface Set . . . . . . . . . . . . . . . . . . . 14 75 7.2. Domain Set . . . . . . . . . . . . . . . . . . . . . . . 15 76 7.3. Seed Set . . . . . . . . . . . . . . . . . . . . . . . . 15 77 7.4. Buffered Message Set . . . . . . . . . . . . . . . . . . 15 78 8. MPL Seed Sequence Numbers . . . . . . . . . . . . . . . . . . 16 79 9. MPL Data Messages . . . . . . . . . . . . . . . . . . . . . . 16 80 9.1. MPL Data Message Generation . . . . . . . . . . . . . . . 16 81 9.2. MPL Data Message Transmission . . . . . . . . . . . . . . 17 82 9.3. MPL Data Message Processing . . . . . . . . . . . . . . . 18 83 10. MPL Control Messages . . . . . . . . . . . . . . . . . . . . 19 84 10.1. MPL Control Message Generation . . . . . . . . . . . . . 19 85 10.2. MPL Control Message Transmission . . . . . . . . . . . . 19 86 10.3. MPL Control Message Processing . . . . . . . . . . . . . 20 87 11. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 21 88 12. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 21 89 12.1. MPL Option Type . . . . . . . . . . . . . . . . . . . . 21 90 12.2. MPL ICMPv6 Type . . . . . . . . . . . . . . . . . . . . 22 91 12.3. Well-known Multicast Addresses . . . . . . . . . . . . . 22 92 13. Security Considerations . . . . . . . . . . . . . . . . . . . 22 93 14. References . . . . . . . . . . . . . . . . . . . . . . . . . 23 94 14.1. Normative References . . . . . . . . . . . . . . . . . . 23 95 14.2. Informative References . . . . . . . . . . . . . . . . . 24 96 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 24 98 1. Introduction 100 Low power and Lossy Networks typically operate with strict resource 101 constraints in communication, computation, memory, and energy. Such 102 resource constraints may preclude the use of existing IPv6 multicast 103 routing and forwarding mechanisms. Traditional IP multicast delivery 104 typically relies on topology maintenance mechanisms to discover and 105 maintain routes to all subscribers of a multicast group (e.g. 106 [RFC3973] [RFC4601]). However, maintaining such topologies in LLNs 107 is costly and may not be feasible given the available resources. 109 Memory constraints may limit devices to maintaining links/routes to 110 one or a few neighbors. For this reason, the Routing Protocol for 111 LLNs (RPL) specifies both storing and non-storing modes [RFC6550]. 112 The latter allows RPL routers to maintain only one or a few default 113 routes towards a LLN Border Router (LBR) and use source routing to 114 forward messages away from the LBR. For the same reasons, a LLN 115 device may not be able to maintain a multicast routing topology when 116 operating with limited memory. 118 Furthermore, the dynamic properties of wireless networks can make the 119 cost of maintaining a multicast routing topology prohibitively 120 expensive. In wireless environments, topology maintenance may 121 involve selecting a connected dominating set used to forward 122 multicast messages to all nodes in an administrative domain. 123 However, existing mechanisms often require two-hop topology 124 information and the cost of maintaining such information grows 125 polynomially with network density. 127 This document specifies the Multicast Protocol for Low power and 128 Lossy Networks (MPL), which provides IPv6 multicast forwarding in 129 constrained networks. MPL avoids the need to construct or maintain 130 any multicast routing topology, disseminating multicast messages to 131 all MPL Forwarders in an MPL Domain. By using the Trickle algorithm 132 [RFC6206], MPL requires only small, constant state for each MPL 133 device that initiates disseminations. The Trickle algorithm also 134 allows MPL to be density-aware, allowing the communication rate to 135 scale logarithmically with density. 137 2. Terminology 139 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 140 "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and 141 "OPTIONAL" in this document are to be interpreted as described in 142 [RFC2119]. 144 The following terms are used throughout this document: 146 MPL Forwarder - A router that implements this protocol. An MPL 147 Forwarder is equipped with at least one MPL 148 Interface. 150 MPL Interface - An MPL Forwarder's attachment to a 151 communications medium, over which it transmits 152 and receives MPL Data Messages and MPL Control 153 Messages according to this specification. An MPL 154 Interface is assigned one or more unicast 155 addresses and is subscribed to one or more MPL 156 Domain Addresses. 158 MPL Domain Address - A multicast address that identifies the set of 159 MPL Interfaces within an MPL Domain. MPL Data 160 Messages disseminated in an MPL Domain have the 161 associated MPL Domain Address as their 162 destination address. 164 MPL Domain - A scope zone, as defined in [RFC4007], in which 165 MPL Interfaces subscribe to the same MPL Domain 166 Address and participate in disseminating MPL Data 167 Messages. 169 MPL Data Message - A multicast message that is used to communicate 170 a multicast payload between MPL Forwarders within 171 an MPL domain. An MPL Data Message contains an 172 MPL Option in the IPv6 header and has as its 173 destination address the MPL Domain Address 174 corresponding to the MPL Domain. 176 MPL Control Message - A link-local multicast message that is used to 177 communicate information about recently received 178 MPL Data Messages to neighboring MPL Forwarders. 180 MPL Seed - An MPL Forwarder that generates MPL Data 181 Messages and serves as an entry point into an MPL 182 Domain. 184 MPL Seed Identifier - An unsigned integer that uniquely identifies an 185 MPL Seed within an MPL Domain. 187 3. Applicability Statement 189 This protocol is an IPv6 multicast forwarding protocol designed for 190 the communication characteristics and resource constraints of Low- 191 Power and Lossy Networks. By implementing controlled disseminations 192 of multicast messages using the Trickle algorithm, this protocol is 193 designed for networks that communicate using low-power and lossy 194 links with widely varying topologies in both the space and time 195 dimensions. 197 While designed specifically for Low-Power and Lossy Networks, this 198 protocol is not limited to use over such networks. This protocol may 199 be applicable to any network where no multicast routing state is 200 desired. This protocol may also be used in environments where only a 201 subset of links are considered Low-Power and Lossy links. 203 A host need not be aware that their multicast is supported by MPL as 204 long as its attachment router forwards multicast messages between the 205 MPL Domain and the host. However, a host may choose to implement MPL 206 so that it can take advantage of the broadcast medium inherent in 207 many Low-Power and Lossy Networks and receive multicast messages 208 carried by MPL directly. 210 4. Protocol Overview 212 The goal of MPL is to deliver multicast messages to all interfaces 213 that subscribe to the multicast messages' destination address within 214 an MPL Domain. 216 4.1. MPL Domains 218 An MPL Domain is a scope zone, as defined in [RFC4007], in which MPL 219 Interfaces subscribe to the same MPL Domain Address and participate 220 in disseminating MPL Data Messages. 222 By default, an MPL Forwarder SHOULD participate in an MPL Domain 223 identified by the ALL_MPL_FORWARDERS multicast address with a scope 224 value of 3 (Realm-Local) [I-D.ietf-6man-multicast-scopes]. 226 When MPL is used in deployments that use administratively defined 227 scopes that cover, for example, multiple subnets based on different 228 underlying network technologies, Admin-Local scope (scop value 4) or 229 Site-Local scope (scop value 5) SHOULD be used. 231 An MPL Forwarder MAY participate in additional MPL Domains identified 232 by other multicast addresses. An MPL Interface MUST subscribe to the 233 MPL Domain Addresses for the MPL Domains that it participates in. 234 The assignment of other multicast addresses is out of scope. 236 For each MPL Domain Address that an MPL Interface subscribes to, the 237 MPL Interface MUST also subscribe to the same MPL Domain Address with 238 a scope value of 2 (link-local) when reactive forwarding is in use 239 (i.e. when communicating MPL Control Messages). 241 4.2. Information Base Overview 243 A node records necessary protocol state in the following information 244 sets: 246 o The Local Interface Set records the set of local MPL Interfaces 247 and the unicast addresses assigned to those MPL Interfaces. 249 o The Domain Set records the set of MPL Domain Addresses and the 250 local MPL Interfaces that subscribe to those addresses. 252 o A Seed Set records information about received MPL Data Messages 253 received from an MPL Seed within an MPL Domain. Each MPL Domain 254 has an associated Seed Set. A Seed Set maintains the minimum 255 sequence number for MPL Data Messages that the MPL Forwarder is 256 willing to receive or has buffered in its Buffered Message Set 257 from an MPL Seed. MPL uses Seed Sets and Buffered Message Sets to 258 determine when to accept an MPL Data Message, process its payload, 259 and retransmit it. 261 o A Buffered Message Set records recently received MPL Data Messages 262 from an MPL Seed within an MPL Domain. Each MPL Domain has an 263 associated Buffered Message Set. MPL Data Messages resident in a 264 Buffered Message Set have sequence numbers that are greater than 265 or equal to the minimum threshold maintained in the corresponding 266 Seed Set. MPL uses Buffered Message Sets to store MPL Data 267 Messages that may be transmitted by the MPL Forwarder for 268 forwarding. 270 4.3. Overview 272 MPL achieves its goal by implementing a controlled flood that 273 attempts to disseminate the multicast data message to all interfaces 274 within an MPL Domain. MPL performs the following tasks to 275 disseminate a multicast message: 277 o When having a multicast message to forward into an MPL Domain, the 278 MPL Seed generates an MPL Data Message that includes the MPL 279 Domain Address as the IPv6 Destination Address, the MPL Seed 280 Identifier, a newly generated sequence number, and the multicast 281 message. If the multicast destination address is not the MPL 282 Domain Address, IP-in-IP [RFC2473] is used to encapsulate the 283 multicast message in an MPL Data Message, preserving the original 284 IPv6 Destination Address. 286 o Upon receiving an MPL Data Message, the MPL Forwarder extracts the 287 MPL Seed and sequence number and determines whether or not the MPL 288 Data Message was previously received using the MPL Domain's Seed 289 Set and Buffered Message Set. 291 * If the sequence number is less than the lower-bound sequence 292 number maintained in the Seed Set or a message with the same 293 sequence number exists within the Buffered Message Set, the MPL 294 Forwarder marks the MPL Data Message as old. 296 * Otherwise, the MPL Forwarder marks the MPL Data Message as new. 298 o For each newly received MPL Data Message, an MPL Forwarder updates 299 the Seed Set, adds the MPL Data Message into the Buffered Message 300 Set, processes its payload, and multicasts the MPL Data Message a 301 number of times on all MPL Interfaces participating in the same 302 MPL Domain to forward the message. 304 o Each MPL Forwarder may periodically link-local multicast MPL 305 Control Messages on MPL Interfaces to communicate information 306 contained in an MPL Domain's Seed Set and Buffered Message Set. 308 o Upon receiving an MPL Control Message, an MPL Forwarder determines 309 whether there are any new MPL Data Messages that have yet to be 310 received by the MPL Control Message's source and multicasts those 311 MPL Data Messages. 313 MPL's configuration parameters allow two forwarding strategies for 314 disseminating MPL Data Messages via MPL Interfaces. 316 Proactive Forwarding - With proactive forwarding, an MPL Forwarder 317 schedules transmissions of MPL Data Messages using the Trickle 318 algorithm, without any prior indication that neighboring nodes 319 have yet to receive the message. After transmitting the MPL Data 320 Message a limited number of times, the MPL Forwarder may terminate 321 proactive forwarding for the MPL Data Message. 323 Reactive Forwarding - With reactive forwarding, an MPL Forwarder 324 link-local multicasts MPL Control Messages using the Trickle 325 algorithm [RFC6206]. MPL Forwarders use MPL Control Messages to 326 discover new MPL Data Messages that have not yet been received. 327 When discovering that a neighboring MPL Forwarder has not yet 328 received an MPL Data Message, the MPL Forwarder schedules those 329 MPL Data Messages for transmission using the Trickle algorithm. 331 Note that the use of proactive and reactive forwarding strategies 332 within the same MPL Domain are not mutually exclusive and may be used 333 simultaneously. For example, upon receiving a new MPL Data Message 334 when both proactive and reactive forwarding techniques are enabled, 335 an MPL Forwarder will proactively retransmit the MPL Data Message a 336 limited number of times and schedule further transmissions upon 337 receiving MPL Control Messages. 339 4.4. Signaling Overview 341 This protocol generates and processes the following messages: 343 MPL Data Message - Generated by an MPL Seed to deliver a multicast 344 message across an MPL Domain. The MPL Data Message's source is an 345 address in the Local Interface Set of the MPL Seed that generated 346 the message and is valid within the MPL Domain. The MPL Data 347 Message's destination is the MPL Domain Address corresponding to 348 the MPL Domain. An MPL Data Message contains: 350 * The Seed Identifier of the MPL Seed that generated the MPL Data 351 Message. 353 * The sequence number of the MPL Seed that generated the MPL Data 354 Message. 356 * The original multicast message. 358 MPL Control Message - Generated by an MPL Forwarder to communicate 359 information contained in an MPL Domain's Seed Set and Buffered 360 Message Set to neighboring MPL Forwarders. An MPL Control Message 361 contains a list of tuples for each entry in the Seed Set. Each 362 tuple contains: 364 * The minimum sequence number maintained in the Seed Set for the 365 MPL Seed. 367 * A bit-vector indicating the sequence numbers of MPL Data 368 Messages resident in the Buffered Message Set for the MPL Seed, 369 where the first bit represents a sequence number equal to the 370 minimum threshold maintained in the Seed Set. 372 * The length of the bit-vector. 374 5. MPL Parameters and Constants 376 This section describes various program and networking parameters and 377 constants used by MPL. 379 5.1. MPL Multicast Addresses 381 MPL makes use of MPL Domain Addresses to identify MPL Interfaces of 382 an MPL Domain. By default, MPL Forwarders subscribe to the 383 ALL_MPL_FORWARDERS multicast address with a scope value of 3 384 [I-D.ietf-6man-multicast-scopes]. 386 For each MPL Domain Address that an MPL Interface subscribes to, the 387 MPL Interface MUST also subscribe to the MPL Domain Address with a 388 scope value of 2 (link-local) when reactive forwarding is in use. 389 MPL Forwarders use the link-scoped MPL Domain Address to communicate 390 MPL Control Messages to neighboring (i.e. on-link) MPL Forwarders. 392 5.2. MPL Message Types 394 MPL defines an IPv6 Option for carrying an MPL Seed Identifier and a 395 sequence number within an MPL Data Message. The IPv6 Option Type has 396 value 0x6D. 398 MPL defines an ICMPv6 Message (MPL Control Message) for communicating 399 information contained in an MPL Domain's Seed Set and Buffered 400 Message Set to neighboring MPL Forwarders. The MPL Control Message 401 has ICMPv6 Type MPL_ICMP_TYPE. 403 5.3. MPL Seed Identifiers 405 MPL uses MPL Seed Identifiers to uniquely identify MPL Seeds within 406 an MPL Domain. For each MPL Domain that the MPL Forwarder serves as 407 an MPL Seed, the MPL Forwarder MUST have an associated MPL Seed 408 Identifier. An MPL Forwarder MAY use the same MPL Seed Identifier 409 across multiple MPL Domains, but the MPL Seed Identifier MUST be 410 unique within each MPL Domain. The mechanism for assigning and 411 verifying uniqueness of MPL Seed Identifiers is not specified in this 412 document. 414 5.4. MPL Parameters 416 PROACTIVE_FORWARDING A boolean value that indicates whether the MPL 417 Forwarder schedules MPL Data Message transmissions after receiving 418 them for the first time. PROACTIVE_FORWARDING has a default value 419 of TRUE. The mechanism for setting PROACTIVE_FORWARDING is not 420 specified within this document. 422 SEED_SET_ENTRY_LIFETIME The minimum lifetime for an entry in the 423 Seed Set. SEED_SET_ENTRY_LIFETIME has a default value of 30 424 minutes. It is RECOMMENDED that all MPL Forwarders use the same 425 value for SEED_SET_ENTRY_LIFETIME for a given MPL Domain and use a 426 default value of 30 minutes. The mechanism for setting 427 SEED_SET_ENTRY_LIFETIME is not specified within this document. 429 As specified in [RFC6206], a Trickle timer runs for a defined 430 interval and has three configuration parameters: the minimum interval 431 size Imin, the maximum interval size Imax, and a redundancy constant 432 k. 434 This specification defines a fourth Trickle configuration parameter, 435 TimerExpirations, which indicates the number of Trickle timer 436 expiration events that occur before terminating the Trickle algorithm 437 for a given MPL Data Message or MPL Control Message. 439 Each MPL Interface uses the following Trickle parameters for MPL Data 440 Message and MPL Control Message transmissions. 442 DATA_MESSAGE_IMIN The minimum Trickle timer interval, as defined in 443 [RFC6206], for MPL Data Message transmissions. DATA_MESSAGE_IMIN 444 has a default value of 10 times the expected link-layer latency. 446 DATA MESSAGE_IMAX The maximum Trickle timer interval, as defined in 447 [RFC6206], for MPL Data Message transmissions. DATA_MESSAGE_IMAX 448 has a default value equal to DATA_MESSAGE_IMIN. 450 DATA_MESSAGE_K The redundancy constant, as defined in [RFC6206], for 451 MPL Data Message transmissions. DATA_MESSAGE_K has a default 452 value of 1. 454 DATA_MESSAGE_TIMER_EXPIRATIONS The number of Trickle timer 455 expirations that occur before terminating the Trickle algorithm's 456 retransmission of a given MPL Data Message. 457 DATA_MESSAGE_TIMER_EXPIRATIONS has a default value of 3. 459 CONTROL_MESSAGE_IMIN The minimum Trickle timer interval, as defined 460 in [RFC6206], for MPL Control Message transmissions. 461 CONTROL_MESSAGE_IMIN has a default value of 10 times the worst- 462 case link-layer latency. 464 CONTROL_MESSAGE_IMAX The maximum Trickle timer interval, as defined 465 in [RFC6206], for MPL Control Message transmissions. 466 CONTROL_MESSAGE_IMAX has a default value of 5 minutes. 468 CONTROL_MESSAGE_K The redundancy constant, as defined in [RFC6206], 469 for MPL Control Message transmissions. CONTROL_MESSAGE_K has a 470 default value of 1. 472 CONTROL_MESSAGE_TIMER_EXPIRATIONS The number of Trickle timer 473 expirations that occur before terminating the Trickle algorithm 474 for MPL Control Message transmissions. 475 CONTROL_MESSAGE_TIMER_EXPIRATIONS has a default value of 10. 477 Following [RFC6206], it is RECOMMENDED that all MPL Interfaces 478 attached to the same link of a given MPL Domain use the same values 479 for the Trickle Parameters above for a given MPL Domain. The 480 mechanism for setting the Trickle Parameters is not specified within 481 this document. 483 The default MPL parameters specify a forwarding strategy that 484 utilizes both proactive and reactive techniques. Using these default 485 values, an MPL Forwarder proactively transmits any new MPL Data 486 Messages it receives then uses MPL Control Messages to trigger 487 additional MPL Data Message retransmissions where message drops are 488 detected. Setting DATA_MESSAGE_IMAX to the same as DATA_MESSAGE_IMIN 489 in this case is acceptable since subsequent MPL Data Message 490 retransmissions are triggered by MPL Control Messages, where 491 CONTROL_MESSAGE_IMAX is greater than CONTROL_MESSAGE_IMIN. 493 6. Protocol Message Formats 495 The protocol messages generated and processed by an MPL Forwarder are 496 described in this section. 498 6.1. MPL Option 500 The MPL Option is carried in MPL Data Messages in an IPv6 Hop-by-Hop 501 Options header, immediately following the IPv6 header. The MPL 502 Option has the following format: 504 0 1 2 3 505 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 506 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 507 | Option Type | Opt Data Len | 508 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 509 | S |M|V| rsv | sequence | seed-id (optional) | 510 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 512 Option Type 0x6D. 514 Opt Data Len Length of the Option Data field in octets. 516 S 2-bit unsigned integer. Identifies the length of 517 seed-id. 0 indicates that the seed-id is the 518 IPv6 Source Address and not included in the MPL 519 Option. 1 indicates that the seed-id is a 16-bit 520 unsigned integer. 2 indicates that the seed-id 521 is a 64-bit unsigned integer. 3 indicates that 522 the seed-id is a 128-bit unsigned integer. 524 M 1-bit flag. 1 indicates that the value in 525 sequence is known to be the largest sequence 526 number that was received from the MPL Seed. 528 V 1-bit flag. 0 indicates that the MPL Option 529 conforms to this specification. MPL Data 530 Messages with an MPL Option in which this flag is 531 1 MUST be dropped. 533 rsv 4-bit reserved field. MUST be set to 0 on 534 transmission and ignored on reception. 536 sequence 8-bit unsigned integer. Identifies relative 537 ordering of MPL Data Messages from the MPL Seed 538 identified by seed-id. 540 seed-id Uniquely identifies the MPL Seed that initiated 541 dissemination of the MPL Data Message. The size 542 of seed-id is indicated by the S field. 544 The Option Data (in particular the M flag) of the MPL Option is 545 updated by MPL Forwarders as the MPL Data Message is forwarded. 546 Nodes that do not understand the MPL Option MUST discard the MPL Data 547 Message. Thus, according to [RFC2460] the three high order bits of 548 the Option Type are set to '011'. The Option Data length is 549 variable. 551 The seed-id uniquely identifies an MPL Seed. When seed-id is 128 552 bits (S=3), the MPL seed MAY use an IPv6 address assigned to one of 553 its interfaces that is unique within the MPL Domain. Managing MPL 554 Seed Identifiers is not within scope of this document. 556 The sequence field establishes a total ordering of MPL Data Messages 557 generated by an MPL Seed for an MPL Domain. The MPL Seed MUST 558 increment the sequence field's value on each new MPL Data Message 559 that it generates for an MPL Domain. Implementations MUST follow the 560 Serial Number Arithmetic as defined in [RFC1982] when incrementing a 561 sequence value or comparing two sequence values. 563 Future updates to this specification may define additional fields 564 following the seed-id field. 566 6.2. MPL Control Message 568 An MPL Forwarder uses ICMPv6 messages to communicate information 569 contained in an MPL Domain's Seed Set and Buffered Message Set to 570 neighboring MPL Forwarders. The MPL Control Message has the 571 following format: 573 0 1 2 3 574 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 575 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 576 | Type | Code | Checksum | 577 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 578 | | 579 . MPL Seed Info[0..n] . 580 . . 581 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 583 IP Fields: 585 Source Address An IPv6 address in the AddressSet of the 586 corresponding MPL Interface and MUST be valid 587 within the MPL Domain. 589 Destination Address The link-scoped MPL Domain Address corresponding 590 to the MPL Domain. 592 Hop Limit 255 594 ICMPv6 Fields: 596 Type MPL_ICMP_TYPE 598 Code 0 600 Checksum The ICMP checksum. See [RFC4443]. 602 MPL Seed Info[0..n] List of zero or more MPL Seed Info entries. 604 The MPL Control Message indicates the sequence numbers of MPL Data 605 Messages that are within the MPL Domain's Buffered Message Set. The 606 MPL Control Message also indicates the sequence numbers of MPL Data 607 Messages that an MPL Forwarder is willing to receive. The MPL 608 Control Message allows neighboring MPL Forwarders to determine 609 whether there are any new MPL Data Messages to exchange. 611 6.3. MPL Seed Info 613 An MPL Seed Info encodes the minimum sequence number for an MPL Seed 614 maintained in the MPL Domain's Seed Set. The MPL Seed Info also 615 indicates the sequence numbers of MPL Data Messages generated by the 616 MPL Seed that are stored within the MPL Domain's Buffered Message 617 Set. The MPL Seed Info has the following format: 619 0 1 2 3 620 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 621 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 622 | min-seqno | bm-len | S | seed-id (0/2/8/16 octets) | 623 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 624 | | 625 . buffered-mpl-messages (variable length) . 626 . . 627 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 629 min-seqno 8-bit unsigned integer. The lower-bound sequence 630 number for the MPL Seed. 632 bm-len 6-bit unsigned integer. The size of buffered- 633 mpl-messages in octets. 635 S 2-bit unsigned integer. Identifies the length of 636 seed-id. 0 indicates that the seed-id value is 637 the IPv6 Source Address and not included in the 638 MPL Seed Info. 1 indicates that the seed-id 639 value is a 16-bit unsigned integer. 2 indicates 640 that the seed-id value is a 64-bit unsigned 641 integer. 3 indicates that the seed-id is a 642 128-bit unsigned integer. 644 seed-id Variable-length unsigned integer. Indicates the 645 MPL Seed associated with this MPL Seed Info. 647 buffered-mpl-messages Variable-length bit vector. Identifies the 648 sequence numbers of MPL Data Messages maintained 649 in the corresponding Buffered Message Set for the 650 MPL Seed. The i'th bit represents a sequence 651 number of min-seqno + i. '0' indicates that the 652 corresponding MPL Data Message does not exist in 653 the Buffered Message Set. '1' indicates that the 654 corresponding MPL Data Message does exist in the 655 Buffered Message Set. 657 The MPL Seed Info does not have any octet alignment requirement. 659 7. Information Base 661 7.1. Local Interface Set 663 The Local Interface Set records the local MPL Interfaces of an MPL 664 Forwarder. The Local Interface Set consists of Local Interface 665 Tuples, one per MPL Interface: (AddressSet). 667 AddressSet - a set of unicast addresses assigned to the MPL 668 Interface. 670 7.2. Domain Set 672 The Domain Set records the MPL Interfaces that subscribe to each MPL 673 Domain Address. The Domain Set consists of MPL Domain Tuples, one 674 per MPL Domain: (MPLInterfaceSet). 676 MPLInterfaceSet - a set of MPL Interfaces that subscribe to the MPL 677 Domain Address that identifies the MPL Domain. 679 7.3. Seed Set 681 A Seed Set records a sliding window used to determine the sequence 682 numbers of MPL Data Messages that an MPL Forwarder is willing to 683 accept generated by the MPL Seed. An MPL Forwarder maintains a Seed 684 Set for each MPL Domain that it participates in. A Seed Set consists 685 of MPL Seed Tuples: (SeedID, MinSequence, Lifetime). 687 SeedID - the identifier for the MPL Seed. 689 MinSequence - a lower-bound sequence number that represents the 690 sequence number of the oldest MPL Data Message the MPL Forwarder 691 is willing to receive or transmit. An MPL Forwarder MUST ignore 692 any MPL Data Message that has sequence value less than than 693 MinSequence. 695 Lifetime - indicates the minimum remaining lifetime of the Seed Set 696 entry. An MPL Forwarder MUST NOT free a Seed Set entry before the 697 remaining lifetime expires. 699 7.4. Buffered Message Set 701 A Buffered Message Set records recently received MPL Data Messages 702 from an MPL Seed within an MPL Domain. An MPL Forwarder uses a 703 Buffered Message Set to buffer MPL Data Messages while the MPL 704 Forwarder is forwarding the MPL Data Messages. An MPL Forwarder 705 maintains a Buffered Message Set for each MPL Domain that it 706 participates in. A Buffered Message Set consists of Buffered Message 707 Tuples: (SeedID, SequenceNumber, DataMessage). 709 SeedID - the identifier for the MPL Seed that generated the MPL Data 710 Message. 712 SequenceNumber - the sequence number for the MPL Data Message. 714 DataMessage - the MPL Data Message. 716 All MPL Data Messages within a Buffered Message Set MUST have a 717 sequence number greater than or equal to MinSequence for the 718 corresponding SeedID. When increasing MinSequence for an MPL Seed, 719 the MPL Forwarder MUST delete any MPL Data Messages from the 720 corresponding Buffered Message Set that have sequence numbers less 721 than MinSequence. 723 8. MPL Seed Sequence Numbers 725 Each MPL Seed maintains a sequence number for each MPL Domain that it 726 serves. The sequence numbers are included in MPL Data Messages 727 generated by the MPL Seed. The MPL Seed MUST increment the sequence 728 number for each MPL Data Message that it generates for an MPL Domain. 729 Implementations MUST follow the Serial Number Arithmetic as defined 730 in [RFC1982] when incrementing a sequence value or comparing two 731 sequence values. This sequence number is used to establish a total 732 ordering of MPL Data Messages generated by an MPL Seed for an MPL 733 Domain. 735 9. MPL Data Messages 737 9.1. MPL Data Message Generation 739 MPL Data Messages are generated by MPL Seeds when these messages 740 enter the MPL Domain. All MPL Data messages have the following 741 properties: 743 o The IPv6 Source Address MUST be an address in the AddressSet of a 744 corresponding MPL Interface and MUST be valid within the MPL 745 Domain. 747 o The IPv6 Destination Address MUST be set to the MPL Domain Address 748 corresponding to the MPL Domain. 750 o An MPL Data Message MUST contain an MPL Option in its IPv6 Header 751 to identify the MPL Seed that generated the message and the 752 ordering relative to other MPL Data Messages generated by the MPL 753 Seed. 755 When the destination address is an MPL Domain Address and the source 756 address is in the AddressLIst of an MPL Interface that belongs to 757 that MPL Domain Address, the application message and the MPL Data 758 Message MAY be identical. In other words, the MPL Data Message may 759 contain a single IPv6 header that includes the MPL Option. 761 Otherwise, IPv6-in-IPv6 encapsulation MUST be used to satisfy the MPL 762 Data Message requirements listed above [RFC2473]. The complete IPv6 763 -in-IPv6 message forms an MPL Data Message. The outer IPv6 header 764 conforms to the MPL Data Message requirements listed above. The 765 encapsulated IPv6 datagram encodes the multicast data message that is 766 communicated beyond the MPL Domain. 768 9.2. MPL Data Message Transmission 770 An MPL Forwarder manages transmission of MPL Data Messages in its 771 Buffered Message Sets using the Trickle algorithm [RFC6206]. An MPL 772 Forwarder MUST use a separate Trickle timer for each MPL Data Message 773 that it is actively forwarding. In accordance with Section 5 of RFC 774 6206 [RFC6206], this document defines the following: 776 o This document defines a "consistent" transmission as receiving an 777 MPL Data Message that has the same MPL Domain Address, seed-id, 778 and sequence value as the MPL Data Message managed by the Trickle 779 timer. 781 o This document defines an "inconsistent" transmission as receiving 782 an MPL Data Message that has the same MPL Domain Address, seed-id 783 value, and the M flag set, but has a sequence value less than MPL 784 Data Message managed by the Trickle timer. 786 o This document does not define any external "events". 788 o This document defines MPL Data Messages as Trickle messages. 790 o The actions outside the Trickle algorithm that the protocol takes 791 involve managing the MPL Domain's Seed Set and Buffered Message 792 Set. 794 As specified in [RFC6206], a Trickle timer has three variables: the 795 current interval size I, a time within the current interval t, and a 796 counter c. MPL defines a fourth variable, e, which counts the number 797 of Trickle timer expiration events since the Trickle timer was last 798 reset. 800 After DATA_MESSAGE_TIMER_EXPIRATIONS Trickle timer events, the MPL 801 Forwarder MUST disable the Trickle timer. When a buffered MPL Data 802 Message does not have an associated Trickle timer, the MPL Forwarder 803 MAY delete the message from the Buffered Message Set by advancing 804 MinSequence of the corresponding MPL Seed in the Seed Set. When the 805 MPL Forwarder no longer buffers any messages for an MPL Seed, the MPL 806 Forwarder MUST NOT increment MinSequence for that MPL Seed. 808 When transmitting an MPL Data Message, the MPL Forwarder MUST either 809 set the M flag to zero or set it to a level that indicates whether or 810 not the message's sequence number is the largest value that has been 811 received from the MPL Seed. 813 9.3. MPL Data Message Processing 815 Upon receiving an MPL Data Message, the MPL Forwarder first processes 816 the MPL Option and updates the Trickle timer associated with the MPL 817 Data Message if one exists. 819 Upon receiving an MPL Data Message, an MPL Forwarder MUST perform one 820 of the following actions: 822 o Accept the message and enter the MPL Data Message in the MPL 823 Domain's Buffered Message Set. 825 o Accept the message and update the corresponding MinSequence in the 826 MPL Domain's Seed Set to 1 greater than the message's sequence 827 number. 829 o Discard the message without any change to the MPL Information 830 Base. 832 If a Seed Set entry exists for the MPL Seed, the MPL Forwarder MUST 833 discard the MPL Data Message if its sequence number is less than 834 MinSequence or exists in the Buffered Message Set. 836 If a Seed Set entry does not exist for the MPL Seed, the MPL 837 Forwarder MUST create a new entry for the MPL Seed before accepting 838 the MPL Data Message. 840 If memory is limited, an MPL Forwarder SHOULD reclaim memory 841 resources by: 843 o Incrementing MinSequence entries in a Seed Set and deleting MPL 844 Data Messages in the corresponding Buffered Message Set that fall 845 below the MinSequence value. 847 o Deleting other Seed Set entries that have expired and the 848 corresponding MPL Data Messages in the Buffered Message Set. 850 If the MPL Forwarder accepts the MPL Data Message, the MPL Forwarder 851 MUST perform the following actions: 853 o Reset the Lifetime of the corresponding Seed Set entry to 854 SEED_SET_ENTRY_LIFETIME. 856 o If PROACTIVE_FORWARDING is true, the MPL Forwarder MUST initialize 857 and start a Trickle timer for the MPL Data Message. 859 o If the MPL Control Message Trickle timer is not running and 860 CONTROL_MESSAGE_TIMER_EXPIRATIONS is non-zero, the MPL Forwarder 861 MUST initialize and start the MPL Control Message Trickle timer. 863 o If the MPL Control Message Trickle timer is running, the MPL 864 Forwarder MUST reset the MPL Control Message Trickle timer. 866 10. MPL Control Messages 868 10.1. MPL Control Message Generation 870 An MPL Forwarder generates MPL Control Messages to communicate an MPL 871 Domain's Seed Set and Buffered Message Set to neighboring MPL 872 Forwarders. Each MPL Control Message is generated according to 873 Section 6.2, with an MPL Seed Info for each entry in the MPL Domain's 874 Seed Set. Each MPL Seed Info entry has the following content: 876 o S set to the size of the seed-id field in the MPL Seed Info entry. 878 o min-seqno set to MinSequence of the MPL Seed. 880 o bm-len set to the size of buffered-mpl-messages in octets. 882 o seed-id set to the MPL seed identifier. 884 o buffered-mpl-messages with each bit representing whether or not an 885 MPL Data Message with the corresponding sequence number exists in 886 the Buffered Message Set. The i'th bit represents a sequence 887 number of min-seqno + i. '0' indicates that the corresponding MPL 888 Data Message does not exist in the Buffered Message Set. '1' 889 indicates that the corresponding MPL Data Message does exist in 890 the Buffered Message Set. 892 10.2. MPL Control Message Transmission 894 An MPL Forwarder transmits MPL Control Messages using the Trickle 895 algorithm. An MPL Forwarder maintains a single Trickle timer for 896 each MPL Domain. When CONTROL_MESSAGE_TIMER_EXPIRATIONS is 0, the 897 MPL Forwarder does not execute the Trickle algorithm and does not 898 transmit MPL Control Messages. In accordance with Section 5 of RFC 899 6206 [RFC6206], this document defines the following: 901 o This document defines a "consistent" transmission as receiving an 902 MPL Control Message that results in a determination that neither 903 the receiving nor transmitting node has any new MPL Data Messages 904 to offer. 906 o This document defines an "inconsistent" transmission as receiving 907 an MPL Control Message that results in a determination that either 908 the receiving or transmitting node has at least one new MPL Data 909 Message to offer. 911 o The Trickle timer is reset in response to external "events." This 912 document defines an "event" as increasing MinSequence of any entry 913 in the corresponding Seed Set or adding a message to the 914 corresponding Buffered Message Set. 916 o This document defines an MPL Control Message as a Trickle message. 918 As specified in [RFC6206], a Trickle timer has three variables: the 919 current interval size I, a time within the current interval t, and a 920 counter c. MPL defines a fourth variable, e, which counts the number 921 of Trickle timer expiration events since the Trickle timer was last 922 reset. After CONTROL_MESSAGE_TIMER_EXPIRATIONS Trickle timer events, 923 the MPL Forwarder MUST disable the Trickle timer. 925 10.3. MPL Control Message Processing 927 An MPL Forwarder processes each MPL Control Message that it receives 928 to determine if it has any new MPL Data Messages to receive or offer. 930 An MPL Forwarder determines if a new MPL Data Message has not been 931 received from a neighboring node if any of the following conditions 932 hold true: 934 o The MPL Control Message includes an MPL Seed that does not exist 935 in the MPL Domain's Seed Set. 937 o The MPL Control Message indicates that the neighbor has an MPL 938 Data Message in its Buffered Message Set with sequence number 939 greater than MinSequence (i.e. the i-th bit is set to 1 and min- 940 seqno + i > MinSequence) and is not included in the MPL Domain's 941 Buffered Message Set. 943 When an MPL Forwarder determines that it has not yet received an MPL 944 Data Message buffered by a neighboring device, the MPL Forwarder MUST 945 reset its Trickle timer associated with MPL Control Message 946 transmissions. If an MPL Control Message Trickle timer is not 947 running, the MPL Forwarder MUST initialize and start a new Trickle 948 timer. 950 An MPL Forwarder determines if an MPL Data Message in the Buffered 951 Message Set has not yet been received by a neighboring MPL Forwarder 952 if any of the following conditions hold true: 954 o The MPL Control Message does not include an MPL Seed for the MPL 955 Data Message. 957 o The MPL Data Message's sequence number is greater than or equal to 958 min-seqno and not included in the neighbor's corresponding 959 Buffered Message Set (i.e. the MPL Data Message's sequence number 960 does not have a corresponding bit in buffered-mpl-messages set to 961 1). 963 When an MPL Forwarder determines that it has at least one MPL Data 964 Message in its corresponding Buffered Message Set that has not yet 965 been received by a neighbor, the MPL Forwarder MUST reset the MPL 966 Control Message Trickle timer. Additionally, for each of those 967 entries in the Buffered Message Set, the MPL Forwarder MUST reset the 968 Trickle timer and reset e to 0. If a Trickle timer is not associated 969 with the MPL Data Message, the MPL Forwarder MUST initialize and 970 start a new Trickle timer. 972 11. Acknowledgements 974 The authors would like to acknowledge the helpful comments of Robert 975 Cragie, Esko Dijk, Ralph Droms, Paul Duffy, Adrian Farrel, Ulrich 976 Herberg, Owen Kirby, Kerry Lynn, Joseph Reddy, Michael Richardson, 977 Ines Robles, Don Sturek, Dario Tedeschi, and Peter van der Stok, 978 which greatly improved the document. 980 12. IANA Considerations 982 This document defines one IPv6 Option, a type that must be allocated 983 from the IPv6 "Destination Options and Hop-by-Hop Options" registry 984 of [RFC2780]. 986 This document defines one ICMPv6 Message, a type that must be 987 allocated from the "ICMPv6 "type" Numbers" registry of [RFC4443]. 989 This document registers a well-known multicast address from the 990 Variable Scope Multicast Address registry. 992 12.1. MPL Option Type 994 IANA is requested to allocate an IPv6 Option Type from the IPv6 995 "Destination Options and Hop-by-Hop Options" registry of [RFC2780], 996 as specified in Table 1 below: 998 +-----------+-----+-----+-------+-------------+---------------+ 999 | Hex Value | act | chg | rest | Description | Reference | 1000 +-----------+-----+-----+-------+-------------+---------------+ 1001 | 0x6D | 01 | 1 | 01101 | MPL Option | This Document | 1002 +-----------+-----+-----+-------+-------------+---------------+ 1004 Table 1: IPv6 Option Type Allocation 1006 12.2. MPL ICMPv6 Type 1008 IANA is requested to allocate an ICMPv6 Type from the "ICMPv6 "type" 1009 Numbers" registry of [RFC4443], as specified in Table 2 below: 1011 +------+---------------------+---------------+ 1012 | Type | Name | Reference | 1013 +------+---------------------+---------------+ 1014 | TBD | MPL Control Message | This Document | 1015 +------+---------------------+---------------+ 1017 Table 2: IPv6 Option Type Allocation 1019 In this document, the mnemonic MPL_ICMP_TYPE was used to refer to the 1020 ICMPv6 Type above, which is TBD by IANA. 1022 12.3. Well-known Multicast Addresses 1024 IANA is requested to allocate an IPv6 multicast address, with Group 1025 ID in the range [0x01,0xFF] for 6LoWPAN compression [RFC6282], 1026 "ALL_MPL_FORWARDERS" from the "Variable Scope Multicast Addresses" 1027 sub-registry of the "IPv6 Multicast Address Space" registry [RFC3307] 1028 as specified in Table 3 below: 1030 +---------------------+--------------------+-----------+------------+ 1031 | Address(s) | Description | Reference | Date | 1032 | | | | Registered | 1033 +---------------------+--------------------+-----------+------------+ 1034 | FF0X:0:0:0:0:0:0:FC | ALL_MPL_FORWARDERS | This | 2013-04-10 | 1035 | | | Document | | 1036 +---------------------+--------------------+-----------+------------+ 1038 Table 3: Variable Scope Multicast Address Allocation 1040 13. Security Considerations 1042 MPL uses sequence numbers to maintain a total ordering of MPL Data 1043 Messages from an MPL Seed. The use of sequence numbers allows a 1044 denial-of-service attack where an attacker can spoof a message with a 1045 sufficiently large sequence number to: (i) flush messages from the 1046 Buffered Message List and (ii) increase the MinSequence value for an 1047 MPL Seed in the corresponding Seed Set. The former side effect 1048 allows an attacker to halt the forwarding process of any MPL Data 1049 Messages being disseminated. The latter side effect allows an 1050 attacker to prevent MPL Forwarders from accepting new MPL Data 1051 Messages that an MPL Seed generates while the sequence number is less 1052 than MinSequence. 1054 More generally, the basic ability to inject messages into a Low-power 1055 and Lossy Network can be used as a denial-of-service attack 1056 regardless of what forwarding protocol is used. For these reasons, 1057 Low-power and Lossy Networks typically employ link-layer security 1058 mechanisms to disable an attacker's ability to inject messages. 1060 To prevent attackers from injecting packets through an MPL Forwarder, 1061 the MPL Forwarder MUST NOT accept or forward MPL Data Messages from a 1062 communication interface that does not subscribe to the MPL Domain 1063 Address identified in message's destination address. 1065 MPL uses the Trickle algorithm to manage message transmissions and 1066 the security considerations described in [RFC6206] apply. 1068 14. References 1070 14.1. Normative References 1072 [I-D.ietf-6man-multicast-scopes] 1073 Droms, R., "IPv6 Multicast Address Scopes", draft-ietf- 1074 6man-multicast-scopes-02 (work in progress), November 1075 2013. 1077 [RFC1982] Elz, R. and R. Bush, "Serial Number Arithmetic", RFC 1982, 1078 August 1996. 1080 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 1081 Requirement Levels", BCP 14, RFC 2119, March 1997. 1083 [RFC2460] Deering, S. and R. Hinden, "Internet Protocol, Version 6 1084 (IPv6) Specification", RFC 2460, December 1998. 1086 [RFC2473] Conta, A. and S. Deering, "Generic Packet Tunneling in 1087 IPv6 Specification", RFC 2473, December 1998. 1089 [RFC2780] Bradner, S. and V. Paxson, "IANA Allocation Guidelines For 1090 Values In the Internet Protocol and Related Headers", BCP 1091 37, RFC 2780, March 2000. 1093 [RFC3307] Haberman, B., "Allocation Guidelines for IPv6 Multicast 1094 Addresses", RFC 3307, August 2002. 1096 [RFC4007] Deering, S., Haberman, B., Jinmei, T., Nordmark, E., and 1097 B. Zill, "IPv6 Scoped Address Architecture", RFC 4007, 1098 March 2005. 1100 [RFC4443] Conta, A., Deering, S., and M. Gupta, "Internet Control 1101 Message Protocol (ICMPv6) for the Internet Protocol 1102 Version 6 (IPv6) Specification", RFC 4443, March 2006. 1104 [RFC6206] Levis, P., Clausen, T., Hui, J., Gnawali, O., and J. Ko, 1105 "The Trickle Algorithm", RFC 6206, March 2011. 1107 [RFC6282] Hui, J. and P. Thubert, "Compression Format for IPv6 1108 Datagrams over IEEE 802.15.4-Based Networks", RFC 6282, 1109 September 2011. 1111 [RFC6550] Winter, T., Thubert, P., Brandt, A., Hui, J., Kelsey, R., 1112 Levis, P., Pister, K., Struik, R., Vasseur, JP., and R. 1113 Alexander, "RPL: IPv6 Routing Protocol for Low-Power and 1114 Lossy Networks", RFC 6550, March 2012. 1116 14.2. Informative References 1118 [RFC3973] Adams, A., Nicholas, J., and W. Siadak, "Protocol 1119 Independent Multicast - Dense Mode (PIM-DM): Protocol 1120 Specification (Revised)", RFC 3973, January 2005. 1122 [RFC4601] Fenner, B., Handley, M., Holbrook, H., and I. Kouvelas, 1123 "Protocol Independent Multicast - Sparse Mode (PIM-SM): 1124 Protocol Specification (Revised)", RFC 4601, August 2006. 1126 Authors' Addresses 1128 Jonathan W. Hui 1129 Cisco 1130 170 West Tasman Drive 1131 San Jose, California 95134 1132 USA 1134 Phone: +408 424 1547 1135 Email: jonhui@cisco.com 1136 Richard Kelsey 1137 Silicon Labs 1138 25 Thomson Place 1139 Boston, Massachusetts 02210 1140 USA 1142 Phone: +617 951 1225 1143 Email: richard.kelsey@silabs.com