idnits 2.17.1 draft-ietf-roll-trickle-mcast-06.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 (January 21, 2014) is 3748 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is mentioned on line 1032, but not defined == Missing Reference: '0xFF' is mentioned on line 1032, but not defined == Outdated reference: A later version (-07) exists of draft-ietf-6man-multicast-scopes-02 ** Obsolete normative reference: RFC 2460 (Obsoleted by RFC 8200) -- Obsolete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: July 25, 2014 Silicon Labs 6 January 21, 2014 8 Multicast Protocol for Low power and Lossy Networks (MPL) 9 draft-ietf-roll-trickle-mcast-06 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 July 25, 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 . . . . . . . . . . . . . . . . . 9 66 5.2. MPL Message Types . . . . . . . . . . . . . . . . . . . . 9 67 5.3. MPL Seed Identifiers . . . . . . . . . . . . . . . . . . 9 68 5.4. MPL Forwarder Parameters . . . . . . . . . . . . . . . . 9 69 6. Protocol Message Formats . . . . . . . . . . . . . . . . . . 11 70 6.1. MPL Option . . . . . . . . . . . . . . . . . . . . . . . 11 71 6.2. MPL Control Message . . . . . . . . . . . . . . . . . . . 13 72 6.3. MPL Seed Info . . . . . . . . . . . . . . . . . . . . . . 14 73 7. Information Base . . . . . . . . . . . . . . . . . . . . . . 15 74 7.1. Local Interface Set . . . . . . . . . . . . . . . . . . . 15 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 . . . . . . . . . . . . . . . . . . . . 22 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 Operationally, the scope of this protocol is administratively 204 determined. In other words, the scope of dissemination is determined 205 by routers configured to disallow transmission or reception of MPL 206 messages on a subset of interfaces. 208 A host need not be aware that their multicast is supported by MPL as 209 long as its attachment router forwards multicast messages between the 210 MPL Domain and the host. However, a host may choose to implement MPL 211 so that it can take advantage of the broadcast medium inherent in 212 many Low-Power and Lossy Networks and receive multicast messages 213 carried by MPL directly. 215 4. Protocol Overview 217 The goal of MPL is to deliver multicast messages to all interfaces 218 that subscribe to the multicast messages' destination address within 219 an MPL Domain. 221 4.1. MPL Domains 223 An MPL Domain is a scope zone, as defined in [RFC4007], in which MPL 224 Interfaces subscribe to the same MPL Domain Address and participate 225 in disseminating MPL Data Messages. 227 By default, an MPL Forwarder SHOULD participate in an MPL Domain 228 identified by the ALL_MPL_FORWARDERS multicast address with a scope 229 value of 3 (Realm-Local) [I-D.ietf-6man-multicast-scopes]. 231 When MPL is used in deployments that use administratively defined 232 scopes that cover, for example, multiple subnets based on different 233 underlying network technologies, Admin-Local scope (scop value 4) and 234 /or Site-Local scope (scop value 5) SHOULD be used. 236 An MPL Forwarder MAY participate in additional MPL Domains identified 237 by other multicast addresses. An MPL Interface MUST subscribe to the 238 MPL Domain Addresses for the MPL Domains that it participates in. 239 The assignment of other multicast addresses is out of scope. 241 For each MPL Domain Address that an MPL Interface subscribes to, the 242 MPL Interface MUST also subscribe to the same MPL Domain Address with 243 a scope value of 2 (link-local) when reactive forwarding is in use 244 (i.e. when communicating MPL Control Messages). 246 4.2. Information Base Overview 248 A node records necessary protocol state in the following information 249 sets: 251 o The Local Interface Set records the set of local MPL Interfaces 252 and the unicast addresses assigned to those MPL Interfaces. 254 o The Domain Set records the set of MPL Domain Addresses and the 255 local MPL Interfaces that subscribe to those addresses. 257 o A Seed Set records information about received MPL Data Messages 258 received from an MPL Seed within an MPL Domain. Each MPL Domain 259 has an associated Seed Set. A Seed Set maintains the minimum 260 sequence number for MPL Data Messages that the MPL Forwarder is 261 willing to receive or has buffered in its Buffered Message Set 262 from an MPL Seed. MPL uses Seed Sets and Buffered Message Sets to 263 determine when to accept an MPL Data Message, process its payload, 264 and retransmit it. 266 o A Buffered Message Set records recently received MPL Data Messages 267 from an MPL Seed within an MPL Domain. Each MPL Domain has an 268 associated Buffered Message Set. MPL Data Messages resident in a 269 Buffered Message Set have sequence numbers that are greater than 270 or equal to the minimum threshold maintained in the corresponding 271 Seed Set. MPL uses Buffered Message Sets to store MPL Data 272 Messages that may be transmitted by the MPL Forwarder for 273 forwarding. 275 4.3. Overview 277 MPL achieves its goal by implementing a controlled flood that 278 attempts to disseminate the multicast data message to all interfaces 279 within an MPL Domain. MPL performs the following tasks to 280 disseminate a multicast message: 282 o When having a multicast message to forward into an MPL Domain, the 283 MPL Seed generates an MPL Data Message that includes the MPL 284 Domain Address as the IPv6 Destination Address, the MPL Seed 285 Identifier, a newly generated sequence number, and the multicast 286 message. If the multicast destination address is not the MPL 287 Domain Address, IP-in-IP [RFC2473] is used to encapsulate the 288 multicast message in an MPL Data Message, preserving the original 289 IPv6 Destination Address. 291 o Upon receiving an MPL Data Message, the MPL Forwarder extracts the 292 MPL Seed and sequence number and determines whether or not the MPL 293 Data Message was previously received using the MPL Domain's Seed 294 Set and Buffered Message Set. 296 * If the sequence number is less than the lower-bound sequence 297 number maintained in the Seed Set or a message with the same 298 sequence number exists within the Buffered Message Set, the MPL 299 Forwarder marks the MPL Data Message as old. 301 * Otherwise, the MPL Forwarder marks the MPL Data Message as new. 303 o For each newly received MPL Data Message, an MPL Forwarder updates 304 the Seed Set, adds the MPL Data Message into the Buffered Message 305 Set, processes its payload, and multicasts the MPL Data Message a 306 number of times on all MPL Interfaces participating in the same 307 MPL Domain to forward the message. 309 o Each MPL Forwarder may periodically link-local multicast MPL 310 Control Messages on MPL Interfaces to communicate information 311 contained in an MPL Domain's Seed Set and Buffered Message Set. 313 o Upon receiving an MPL Control Message, an MPL Forwarder determines 314 whether there are any new MPL Data Messages that have yet to be 315 received by the MPL Control Message's source and multicasts those 316 MPL Data Messages. 318 MPL's configuration parameters allow two forwarding strategies for 319 disseminating MPL Data Messages via MPL Interfaces. 321 Proactive Forwarding - With proactive forwarding, an MPL Forwarder 322 schedules transmissions of MPL Data Messages using the Trickle 323 algorithm, without any prior indication that neighboring nodes 324 have yet to receive the message. After transmitting the MPL Data 325 Message a limited number of times, the MPL Forwarder may terminate 326 proactive forwarding for the MPL Data Message. 328 Reactive Forwarding - With reactive forwarding, an MPL Forwarder 329 link-local multicasts MPL Control Messages using the Trickle 330 algorithm [RFC6206]. MPL Forwarders use MPL Control Messages to 331 discover new MPL Data Messages that have not yet been received. 332 When discovering that a neighboring MPL Forwarder has not yet 333 received an MPL Data Message, the MPL Forwarder schedules those 334 MPL Data Messages for transmission using the Trickle algorithm. 336 Note that the use of proactive and reactive forwarding strategies 337 within the same MPL Domain are not mutually exclusive and may be used 338 simultaneously. For example, upon receiving a new MPL Data Message 339 when both proactive and reactive forwarding techniques are enabled, 340 an MPL Forwarder will proactively retransmit the MPL Data Message a 341 limited number of times and schedule further transmissions upon 342 receiving MPL Control Messages. 344 4.4. Signaling Overview 346 This protocol generates and processes the following messages: 348 MPL Data Message - Generated by an MPL Seed to deliver a multicast 349 message across an MPL Domain. The MPL Data Message's source is an 350 address in the Local Interface Set of the MPL Seed that generated 351 the message and is valid within the MPL Domain. The MPL Data 352 Message's destination is the MPL Domain Address corresponding to 353 the MPL Domain. An MPL Data Message contains: 355 * The Seed Identifier of the MPL Seed that generated the MPL Data 356 Message. 358 * The sequence number of the MPL Seed that generated the MPL Data 359 Message. 361 * The original multicast message. 363 MPL Control Message - Generated by an MPL Forwarder to communicate 364 information contained in an MPL Domain's Seed Set and Buffered 365 Message Set to neighboring MPL Forwarders. An MPL Control Message 366 contains a list of tuples for each entry in the Seed Set. Each 367 tuple contains: 369 * The minimum sequence number maintained in the Seed Set for the 370 MPL Seed. 372 * A bit-vector indicating the sequence numbers of MPL Data 373 Messages resident in the Buffered Message Set for the MPL Seed, 374 where the first bit represents a sequence number equal to the 375 minimum threshold maintained in the Seed Set. 377 * The length of the bit-vector. 379 5. MPL Parameters and Constants 381 This section describes various program and networking parameters and 382 constants used by MPL. 384 5.1. MPL Multicast Addresses 386 MPL makes use of MPL Domain Addresses to identify MPL Interfaces of 387 an MPL Domain. By default, MPL Forwarders subscribe to the 388 ALL_MPL_FORWARDERS multicast address with a scope value of 3 389 [I-D.ietf-6man-multicast-scopes]. 391 For each MPL Domain Address that an MPL Interface subscribes to, the 392 MPL Interface MUST also subscribe to the MPL Domain Address with a 393 scope value of 2 (link-local) when reactive forwarding is in use. 394 MPL Forwarders use the link-scoped MPL Domain Address to communicate 395 MPL Control Messages to neighboring (i.e. on-link) MPL Forwarders. 397 5.2. MPL Message Types 399 MPL defines an IPv6 Option for carrying an MPL Seed Identifier and a 400 sequence number within an MPL Data Message. The IPv6 Option Type has 401 value MPL_OPT_TYPE. 403 MPL defines an ICMPv6 Message (MPL Control Message) for communicating 404 information contained in an MPL Domain's Seed Set and Buffered 405 Message Set to neighboring MPL Forwarders. The MPL Control Message 406 has ICMPv6 Type MPL_ICMP_TYPE. 408 5.3. MPL Seed Identifiers 410 MPL uses MPL Seed Identifiers to uniquely identify MPL Seeds within 411 an MPL Domain. For each MPL Domain that the MPL Forwarder serves as 412 an MPL Seed, the MPL Forwarder MUST have an associated MPL Seed 413 Identifier. An MPL Forwarder MAY use the same MPL Seed Identifier 414 across multiple MPL Domains, but the MPL Seed Identifier MUST be 415 unique within each MPL Domain. The mechanism for assigning and 416 verifying uniqueness of MPL Seed Identifiers is not specified in this 417 document. 419 5.4. MPL Forwarder Parameters 421 PROACTIVE_FORWARDING A boolean value that indicates whether the MPL 422 Forwarder schedules MPL Data Message transmissions after receiving 423 them for the first time. It is RECOMMENDED that all MPL 424 Interfaces attached to the same link of a given MPL Domain use the 425 same value for PROACTIVE_FORWARDING and has a default value of 426 TRUE. The mechanism for setting PROACTIVE_FORWARDING is not 427 specified within this document. 429 SEED_SET_ENTRY_LIFETIME The minimum lifetime for an entry in the 430 Seed Set. SEED_SET_ENTRY_LIFETIME has a default value of 30 431 minutes. It is RECOMMENDED that all MPL Forwarders use the same 432 value for SEED_SET_ENTRY_LIFETIME for a given MPL Domain and has a 433 default value of 30 minutes. The mechanism for setting 434 SEED_SET_ENTRY_LIFETIME is not specified within this document. 436 As specified in [RFC6206], a Trickle timer runs for a defined 437 interval and has three configuration parameters: the minimum interval 438 size Imin, the maximum interval size Imax, and a redundancy constant 439 k. 441 This specification defines a fourth Trickle configuration parameter, 442 TimerExpirations, which indicates the number of Trickle timer 443 expiration events that occur before terminating the Trickle algorithm 444 for a given MPL Data Message or MPL Control Message. 446 Each MPL Interface uses the following Trickle parameters for MPL Data 447 Message and MPL Control Message transmissions. 449 DATA_MESSAGE_IMIN The minimum Trickle timer interval, as defined in 450 [RFC6206], for MPL Data Message transmissions. DATA_MESSAGE_IMIN 451 has a default value of 10 times the expected link-layer latency. 453 DATA MESSAGE_IMAX The maximum Trickle timer interval, as defined in 454 [RFC6206], for MPL Data Message transmissions. DATA_MESSAGE_IMAX 455 has a default value equal to DATA_MESSAGE_IMIN. 457 DATA_MESSAGE_K The redundancy constant, as defined in [RFC6206], for 458 MPL Data Message transmissions. DATA_MESSAGE_K has a default 459 value of 1. 461 DATA_MESSAGE_TIMER_EXPIRATIONS The number of Trickle timer 462 expirations that occur before terminating the Trickle algorithm's 463 retransmission of a given MPL Data Message. 464 DATA_MESSAGE_TIMER_EXPIRATIONS has a default value of 3. 466 CONTROL_MESSAGE_IMIN The minimum Trickle timer interval, as defined 467 in [RFC6206], for MPL Control Message transmissions. 468 CONTROL_MESSAGE_IMIN has a default value of 10 times the worst- 469 case link-layer latency. 471 CONTROL_MESSAGE_IMAX The maximum Trickle timer interval, as defined 472 in [RFC6206], for MPL Control Message transmissions. 473 CONTROL_MESSAGE_IMAX has a default value of 5 minutes. 475 CONTROL_MESSAGE_K The redundancy constant, as defined in [RFC6206], 476 for MPL Control Message transmissions. CONTROL_MESSAGE_K has a 477 default value of 1. 479 CONTROL_MESSAGE_TIMER_EXPIRATIONS The number of Trickle timer 480 expirations that occur before terminating the Trickle algorithm 481 for MPL Control Message transmissions. 482 CONTROL_MESSAGE_TIMER_EXPIRATIONS has a default value of 10. 484 Following [RFC6206], it is RECOMMENDED that all MPL Interfaces 485 attached to the same link of a given MPL Domain use the same values 486 for the Trickle Parameters above for a given MPL Domain. The 487 mechanism for setting the Trickle Parameters is not specified within 488 this document. 490 The default Trickle parameter values above combined with the default 491 MPL Forwarder parameters in the prior section specify a forwarding 492 strategy that utilizes both proactive and reactive techniques. Using 493 these default values, an MPL Forwarder proactively transmits any new 494 MPL Data Messages it receives then uses MPL Control Messages to 495 trigger additional MPL Data Message retransmissions where message 496 drops are detected. Setting DATA_MESSAGE_IMAX to the same as 497 DATA_MESSAGE_IMIN in this case is acceptable since subsequent MPL 498 Data Message retransmissions are triggered by MPL Control Messages, 499 where CONTROL_MESSAGE_IMAX is greater than CONTROL_MESSAGE_IMIN. 501 6. Protocol Message Formats 503 The protocol messages generated and processed by an MPL Forwarder are 504 described in this section. 506 6.1. MPL Option 508 The MPL Option is carried in MPL Data Messages in an IPv6 Hop-by-Hop 509 Options header, immediately following the IPv6 header. The MPL 510 Option has the following format: 512 0 1 2 3 513 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 1 514 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 515 | Option Type | Opt Data Len | 516 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 517 | S |M|V| rsv | sequence | seed-id (optional) | 518 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 520 Option Type MPL_OPT_TYPE 522 Opt Data Len Length of the Option Data field in octets. 524 S 2-bit unsigned integer. Identifies the length of 525 seed-id. 0 indicates that the seed-id is the 526 IPv6 Source Address and not included in the MPL 527 Option. 1 indicates that the seed-id is a 16-bit 528 unsigned integer. 2 indicates that the seed-id 529 is a 64-bit unsigned integer. 3 indicates that 530 the seed-id is a 128-bit unsigned integer. 532 M 1-bit flag. 1 indicates that the value in 533 sequence is known to be the largest sequence 534 number that was received from the MPL Seed. 536 V 1-bit flag. 0 indicates that the MPL Option 537 conforms to this specification. MPL Data 538 Messages with an MPL Option in which this flag is 539 1 MUST be dropped. 541 rsv 4-bit reserved field. MUST be set to 0 on 542 transmission and ignored on reception. 544 sequence 8-bit unsigned integer. Identifies relative 545 ordering of MPL Data Messages from the MPL Seed 546 identified by seed-id. 548 seed-id Uniquely identifies the MPL Seed that initiated 549 dissemination of the MPL Data Message. The size 550 of seed-id is indicated by the S field. 552 The Option Data (in particular the M flag) of the MPL Option is 553 updated by MPL Forwarders as the MPL Data Message is forwarded. 554 Nodes that do not understand the MPL Option MUST discard the MPL Data 555 Message. Thus, according to [RFC2460] the three high order bits of 556 the Option Type are set to '011'. The Option Data length is 557 variable. 559 The seed-id uniquely identifies an MPL Seed. When seed-id is 128 560 bits (S=3), the MPL seed MAY use an IPv6 address assigned to one of 561 its interfaces that is unique within the MPL Domain. Managing MPL 562 Seed Identifiers is not within scope of this document. 564 The sequence field establishes a total ordering of MPL Data Messages 565 generated by an MPL Seed for an MPL Domain. The MPL Seed MUST 566 increment the sequence field's value on each new MPL Data Message 567 that it generates for an MPL Domain. Implementations MUST follow the 568 Serial Number Arithmetic as defined in [RFC1982] when incrementing a 569 sequence value or comparing two sequence values. 571 Future updates to this specification may define additional fields 572 following the seed-id field. 574 6.2. MPL Control Message 576 An MPL Forwarder uses ICMPv6 messages to communicate information 577 contained in an MPL Domain's Seed Set and Buffered Message Set to 578 neighboring MPL Forwarders. The MPL Control Message has the 579 following format: 581 0 1 2 3 582 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 1 583 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 584 | Type | Code | Checksum | 585 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 586 | | 587 . MPL Seed Info[0..n] . 588 . . 589 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 591 IP Fields: 593 Source Address An IPv6 address in the AddressSet of the 594 corresponding MPL Interface and MUST be valid 595 within the MPL Domain. 597 Destination Address The link-scoped MPL Domain Address corresponding 598 to the MPL Domain. 600 Hop Limit 255 602 ICMPv6 Fields: 604 Type MPL_ICMP_TYPE 606 Code 0 608 Checksum The ICMP checksum. See [RFC4443]. 610 MPL Seed Info[0..n] List of zero or more MPL Seed Info entries. 612 The MPL Control Message indicates the sequence numbers of MPL Data 613 Messages that are within the MPL Domain's Buffered Message Set. The 614 MPL Control Message also indicates the sequence numbers of MPL Data 615 Messages that an MPL Forwarder is willing to receive. The MPL 616 Control Message allows neighboring MPL Forwarders to determine 617 whether there are any new MPL Data Messages to exchange. 619 6.3. MPL Seed Info 621 An MPL Seed Info encodes the minimum sequence number for an MPL Seed 622 maintained in the MPL Domain's Seed Set. The MPL Seed Info also 623 indicates the sequence numbers of MPL Data Messages generated by the 624 MPL Seed that are stored within the MPL Domain's Buffered Message 625 Set. The MPL Seed Info has the following format: 627 0 1 2 3 628 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 1 629 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 630 | min-seqno | bm-len | S | seed-id (0/2/8/16 octets) | 631 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 632 | | 633 . buffered-mpl-messages (variable length) . 634 . . 635 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 637 min-seqno 8-bit unsigned integer. The lower-bound sequence 638 number for the MPL Seed. 640 bm-len 6-bit unsigned integer. The size of buffered- 641 mpl-messages in octets. 643 S 2-bit unsigned integer. Identifies the length of 644 seed-id. 0 indicates that the seed-id value is 645 the IPv6 Source Address and not included in the 646 MPL Seed Info. 1 indicates that the seed-id 647 value is a 16-bit unsigned integer. 2 indicates 648 that the seed-id value is a 64-bit unsigned 649 integer. 3 indicates that the seed-id is a 650 128-bit unsigned integer. 652 seed-id Variable-length unsigned integer. Indicates the 653 MPL Seed associated with this MPL Seed Info. 655 buffered-mpl-messages Variable-length bit vector. Identifies the 656 sequence numbers of MPL Data Messages maintained 657 in the corresponding Buffered Message Set for the 658 MPL Seed. The i'th bit represents a sequence 659 number of min-seqno + i. '0' indicates that the 660 corresponding MPL Data Message does not exist in 661 the Buffered Message Set. '1' indicates that the 662 corresponding MPL Data Message does exist in the 663 Buffered Message Set. 665 The MPL Seed Info does not have any octet alignment requirement. 667 7. Information Base 669 7.1. Local Interface Set 671 The Local Interface Set records the local MPL Interfaces of an MPL 672 Forwarder. The Local Interface Set consists of Local Interface 673 Tuples, one per MPL Interface: (AddressSet). 675 AddressSet - a set of unicast addresses assigned to the MPL 676 Interface. 678 7.2. Domain Set 680 The Domain Set records the MPL Interfaces that subscribe to each MPL 681 Domain Address. The Domain Set consists of MPL Domain Tuples, one 682 per MPL Domain: (MPLInterfaceSet). 684 MPLInterfaceSet - a set of MPL Interfaces that subscribe to the MPL 685 Domain Address that identifies the MPL Domain. 687 7.3. Seed Set 689 A Seed Set records a sliding window used to determine the sequence 690 numbers of MPL Data Messages that an MPL Forwarder is willing to 691 accept generated by the MPL Seed. An MPL Forwarder maintains a Seed 692 Set for each MPL Domain that it participates in. A Seed Set consists 693 of MPL Seed Tuples: (SeedID, MinSequence, Lifetime). 695 SeedID - the identifier for the MPL Seed. 697 MinSequence - a lower-bound sequence number that represents the 698 sequence number of the oldest MPL Data Message the MPL Forwarder 699 is willing to receive or transmit. An MPL Forwarder MUST ignore 700 any MPL Data Message that has sequence value less than than 701 MinSequence. 703 Lifetime - indicates the minimum remaining lifetime of the Seed Set 704 entry. An MPL Forwarder MUST NOT free a Seed Set entry before the 705 remaining lifetime expires. 707 7.4. Buffered Message Set 709 A Buffered Message Set records recently received MPL Data Messages 710 from an MPL Seed within an MPL Domain. An MPL Forwarder uses a 711 Buffered Message Set to buffer MPL Data Messages while the MPL 712 Forwarder is forwarding the MPL Data Messages. An MPL Forwarder 713 maintains a Buffered Message Set for each MPL Domain that it 714 participates in. A Buffered Message Set consists of Buffered Message 715 Tuples: (SeedID, SequenceNumber, DataMessage). 717 SeedID - the identifier for the MPL Seed that generated the MPL Data 718 Message. 720 SequenceNumber - the sequence number for the MPL Data Message. 722 DataMessage - the MPL Data Message. 724 All MPL Data Messages within a Buffered Message Set MUST have a 725 sequence number greater than or equal to MinSequence for the 726 corresponding SeedID. When increasing MinSequence for an MPL Seed, 727 the MPL Forwarder MUST delete any MPL Data Messages from the 728 corresponding Buffered Message Set that have sequence numbers less 729 than MinSequence. 731 8. MPL Seed Sequence Numbers 733 Each MPL Seed maintains a sequence number for each MPL Domain that it 734 serves. The sequence numbers are included in MPL Data Messages 735 generated by the MPL Seed. The MPL Seed MUST increment the sequence 736 number for each MPL Data Message that it generates for an MPL Domain. 737 Implementations MUST follow the Serial Number Arithmetic as defined 738 in [RFC1982] when incrementing a sequence value or comparing two 739 sequence values. This sequence number is used to establish a total 740 ordering of MPL Data Messages generated by an MPL Seed for an MPL 741 Domain. 743 9. MPL Data Messages 745 9.1. MPL Data Message Generation 747 MPL Data Messages are generated by MPL Seeds when these messages 748 enter the MPL Domain. All MPL Data messages have the following 749 properties: 751 o The IPv6 Source Address MUST be an address in the AddressSet of a 752 corresponding MPL Interface and MUST be valid within the MPL 753 Domain. 755 o The IPv6 Destination Address MUST be set to the MPL Domain Address 756 corresponding to the MPL Domain. 758 o An MPL Data Message MUST contain an MPL Option in its IPv6 Header 759 to identify the MPL Seed that generated the message and the 760 ordering relative to other MPL Data Messages generated by the MPL 761 Seed. 763 When the destination address is an MPL Domain Address and the source 764 address is in the AddressLIst of an MPL Interface that belongs to 765 that MPL Domain Address, the application message and the MPL Data 766 Message MAY be identical. In other words, the MPL Data Message may 767 contain a single IPv6 header that includes the MPL Option. 769 Otherwise, IPv6-in-IPv6 encapsulation MUST be used to satisfy the MPL 770 Data Message requirements listed above [RFC2473]. The complete IPv6 771 -in-IPv6 message forms an MPL Data Message. The outer IPv6 header 772 conforms to the MPL Data Message requirements listed above. The 773 encapsulated IPv6 datagram encodes the multicast data message that is 774 communicated beyond the MPL Domain. 776 9.2. MPL Data Message Transmission 778 An MPL Forwarder manages transmission of MPL Data Messages in its 779 Buffered Message Sets using the Trickle algorithm [RFC6206]. An MPL 780 Forwarder MUST use a separate Trickle timer for each MPL Data Message 781 that it is actively forwarding. In accordance with Section 5 of RFC 782 6206 [RFC6206], this document defines the following: 784 o This document defines a "consistent" transmission as receiving an 785 MPL Data Message that has the same MPL Domain Address, seed-id, 786 and sequence value as the MPL Data Message managed by the Trickle 787 timer. 789 o This document defines an "inconsistent" transmission as receiving 790 an MPL Data Message that has the same MPL Domain Address, seed-id 791 value, and the M flag set, but has a sequence value less than MPL 792 Data Message managed by the Trickle timer. 794 o This document does not define any external "events". 796 o This document defines MPL Data Messages as Trickle messages. 798 o The actions outside the Trickle algorithm that the protocol takes 799 involve managing the MPL Domain's Seed Set and Buffered Message 800 Set. 802 As specified in [RFC6206], a Trickle timer has three variables: the 803 current interval size I, a time within the current interval t, and a 804 counter c. MPL defines a fourth variable, e, which counts the number 805 of Trickle timer expiration events since the Trickle timer was last 806 reset. 808 After DATA_MESSAGE_TIMER_EXPIRATIONS Trickle timer events, the MPL 809 Forwarder MUST disable the Trickle timer. When a buffered MPL Data 810 Message does not have an associated Trickle timer, the MPL Forwarder 811 MAY delete the message from the Buffered Message Set by advancing 812 MinSequence of the corresponding MPL Seed in the Seed Set. When the 813 MPL Forwarder no longer buffers any messages for an MPL Seed, the MPL 814 Forwarder MUST NOT increment MinSequence for that MPL Seed. 816 When transmitting an MPL Data Message, the MPL Forwarder MUST either 817 set the M flag to zero or set it to a level that indicates whether or 818 not the message's sequence number is the largest value that has been 819 received from the MPL Seed. 821 9.3. MPL Data Message Processing 823 Upon receiving an MPL Data Message, the MPL Forwarder first processes 824 the MPL Option and updates the Trickle timer associated with the MPL 825 Data Message if one exists. 827 Upon receiving an MPL Data Message, an MPL Forwarder MUST perform one 828 of the following actions: 830 o Accept the message and enter the MPL Data Message in the MPL 831 Domain's Buffered Message Set. 833 o Accept the message and update the corresponding MinSequence in the 834 MPL Domain's Seed Set to 1 greater than the message's sequence 835 number. 837 o Discard the message without any change to the MPL Information 838 Base. 840 If a Seed Set entry exists for the MPL Seed, the MPL Forwarder MUST 841 discard the MPL Data Message if its sequence number is less than 842 MinSequence or exists in the Buffered Message Set. 844 If a Seed Set entry does not exist for the MPL Seed, the MPL 845 Forwarder MUST create a new entry for the MPL Seed before accepting 846 the MPL Data Message. 848 If memory is limited, an MPL Forwarder SHOULD reclaim memory 849 resources by: 851 o Incrementing MinSequence entries in a Seed Set and deleting MPL 852 Data Messages in the corresponding Buffered Message Set that fall 853 below the MinSequence value. 855 o Deleting other Seed Set entries that have expired and the 856 corresponding MPL Data Messages in the Buffered Message Set. 858 If the MPL Forwarder accepts the MPL Data Message, the MPL Forwarder 859 MUST perform the following actions: 861 o Reset the Lifetime of the corresponding Seed Set entry to 862 SEED_SET_ENTRY_LIFETIME. 864 o If PROACTIVE_FORWARDING is true, the MPL Forwarder MUST initialize 865 and start a Trickle timer for the MPL Data Message. 867 o If the MPL Control Message Trickle timer is not running and 868 CONTROL_MESSAGE_TIMER_EXPIRATIONS is non-zero, the MPL Forwarder 869 MUST initialize and start the MPL Control Message Trickle timer. 871 o If the MPL Control Message Trickle timer is running, the MPL 872 Forwarder MUST reset the MPL Control Message Trickle timer. 874 10. MPL Control Messages 876 10.1. MPL Control Message Generation 878 An MPL Forwarder generates MPL Control Messages to communicate an MPL 879 Domain's Seed Set and Buffered Message Set to neighboring MPL 880 Forwarders. Each MPL Control Message is generated according to 881 Section 6.2, with an MPL Seed Info for each entry in the MPL Domain's 882 Seed Set. Each MPL Seed Info entry has the following content: 884 o S set to the size of the seed-id field in the MPL Seed Info entry. 886 o min-seqno set to MinSequence of the MPL Seed. 888 o bm-len set to the size of buffered-mpl-messages in octets. 890 o seed-id set to the MPL seed identifier. 892 o buffered-mpl-messages with each bit representing whether or not an 893 MPL Data Message with the corresponding sequence number exists in 894 the Buffered Message Set. The i'th bit represents a sequence 895 number of min-seqno + i. '0' indicates that the corresponding MPL 896 Data Message does not exist in the Buffered Message Set. '1' 897 indicates that the corresponding MPL Data Message does exist in 898 the Buffered Message Set. 900 10.2. MPL Control Message Transmission 902 An MPL Forwarder transmits MPL Control Messages using the Trickle 903 algorithm. An MPL Forwarder maintains a single Trickle timer for 904 each MPL Domain. When CONTROL_MESSAGE_TIMER_EXPIRATIONS is 0, the 905 MPL Forwarder does not execute the Trickle algorithm and does not 906 transmit MPL Control Messages. In accordance with Section 5 of RFC 907 6206 [RFC6206], this document defines the following: 909 o This document defines a "consistent" transmission as receiving an 910 MPL Control Message that results in a determination that neither 911 the receiving nor transmitting node has any new MPL Data Messages 912 to offer. 914 o This document defines an "inconsistent" transmission as receiving 915 an MPL Control Message that results in a determination that either 916 the receiving or transmitting node has at least one new MPL Data 917 Message to offer. 919 o The Trickle timer is reset in response to external "events." This 920 document defines an "event" as increasing MinSequence of any entry 921 in the corresponding Seed Set or adding a message to the 922 corresponding Buffered Message Set. 924 o This document defines an MPL Control Message as a Trickle message. 926 As specified in [RFC6206], a Trickle timer has three variables: the 927 current interval size I, a time within the current interval t, and a 928 counter c. MPL defines a fourth variable, e, which counts the number 929 of Trickle timer expiration events since the Trickle timer was last 930 reset. After CONTROL_MESSAGE_TIMER_EXPIRATIONS Trickle timer events, 931 the MPL Forwarder MUST disable the Trickle timer. 933 10.3. MPL Control Message Processing 935 An MPL Forwarder processes each MPL Control Message that it receives 936 to determine if it has any new MPL Data Messages to receive or offer. 938 An MPL Forwarder determines if a new MPL Data Message has not been 939 received from a neighboring node if any of the following conditions 940 hold true: 942 o The MPL Control Message includes an MPL Seed that does not exist 943 in the MPL Domain's Seed Set. 945 o The MPL Control Message indicates that the neighbor has an MPL 946 Data Message in its Buffered Message Set with sequence number 947 greater than MinSequence (i.e. the i-th bit is set to 1 and min- 948 seqno + i > MinSequence) and is not included in the MPL Domain's 949 Buffered Message Set. 951 When an MPL Forwarder determines that it has not yet received an MPL 952 Data Message buffered by a neighboring device, the MPL Forwarder MUST 953 reset its Trickle timer associated with MPL Control Message 954 transmissions. If an MPL Control Message Trickle timer is not 955 running, the MPL Forwarder MUST initialize and start a new Trickle 956 timer. 958 An MPL Forwarder determines if an MPL Data Message in the Buffered 959 Message Set has not yet been received by a neighboring MPL Forwarder 960 if any of the following conditions hold true: 962 o The MPL Control Message does not include an MPL Seed for the MPL 963 Data Message. 965 o The MPL Data Message's sequence number is greater than or equal to 966 min-seqno and not included in the neighbor's corresponding 967 Buffered Message Set (i.e. the MPL Data Message's sequence number 968 does not have a corresponding bit in buffered-mpl-messages set to 969 1). 971 When an MPL Forwarder determines that it has at least one MPL Data 972 Message in its corresponding Buffered Message Set that has not yet 973 been received by a neighbor, the MPL Forwarder MUST reset the MPL 974 Control Message Trickle timer. Additionally, for each of those 975 entries in the Buffered Message Set, the MPL Forwarder MUST reset the 976 Trickle timer and reset e to 0. If a Trickle timer is not associated 977 with the MPL Data Message, the MPL Forwarder MUST initialize and 978 start a new Trickle timer. 980 11. Acknowledgements 982 The authors would like to acknowledge the helpful comments of Robert 983 Cragie, Esko Dijk, Ralph Droms, Paul Duffy, Adrian Farrel, Ulrich 984 Herberg, Owen Kirby, Kerry Lynn, Joseph Reddy, Michael Richardson, 985 Don Sturek, Dario Tedeschi, and Peter van der Stok, which greatly 986 improved the document. 988 12. IANA Considerations 990 This document defines one IPv6 Option, a type that must be allocated 991 from the IPv6 "Destination Options and Hop-by-Hop Options" registry 992 of [RFC2780]. 994 This document defines one ICMPv6 Message, a type that must be 995 allocated from the "ICMPv6 "type" Numbers" registry of [RFC4443]. 997 This document registers two well-known multicast addresses from the 998 IPv6 multicast address space. 1000 12.1. MPL Option Type 1002 IANA is requested to allocate an IPv6 Option Type from the IPv6 1003 "Destination Options and Hop-by-Hop Options" registry of [RFC2780], 1004 as specified in Table 1 below: 1006 +--------------+-----+-----+--------------+-------------+-----------+ 1007 | Mnemonic | act | chg | rest | Description | Reference | 1008 +--------------+-----+-----+--------------+-------------+-----------+ 1009 | MPL_OPT_TYPE | 01 | 1 | TBD | MPL Option | This | 1010 | | | | (suggested | | Document | 1011 | | | | value 01101) | | | 1012 +--------------+-----+-----+--------------+-------------+-----------+ 1014 Table 1: IPv6 Option Type Allocation 1016 12.2. MPL ICMPv6 Type 1018 IANA is requested to allocate an ICMPv6 Type from the "ICMPv6 "type" 1019 Numbers" registry of [RFC4443], as specified in Table 2 below: 1021 +---------------+------+---------------------+---------------+ 1022 | Mnemonic | Type | Name | Reference | 1023 +---------------+------+---------------------+---------------+ 1024 | MPL_ICMP_TYPE | TBD | MPL Control Message | This Document | 1025 +---------------+------+---------------------+---------------+ 1027 Table 2: IPv6 Option Type Allocation 1029 12.3. Well-known Multicast Addresses 1031 IANA is requested to allocate an IPv6 multicast address, with Group 1032 ID in the range [0x01,0xFF] for 6LoWPAN compression [RFC6282], 1033 "ALL_MPL_FORWARDERS" from the "Variable Scope Multicast Addresses" 1034 sub-registry of the "IPv6 Multicast Address Space" registry 1035 [RFC3307]. 1037 13. Security Considerations 1039 MPL uses sequence numbers to maintain a total ordering of MPL Data 1040 Messages from an MPL Seed. The use of sequence numbers allows a 1041 denial-of-service attack where an attacker can spoof a message with a 1042 sufficiently large sequence number to: (i) flush messages from the 1043 Buffered Message List and (ii) increase the MinSequence value for an 1044 MPL Seed in the corresponding Seed Set. The former side effect 1045 allows an attacker to halt the forwarding process of any MPL Data 1046 Messages being disseminated. The latter side effect allows an 1047 attacker to prevent MPL Forwarders from accepting new MPL Data 1048 Messages that an MPL Seed generates while the sequence number is less 1049 than MinSequence. 1051 More generally, the basic ability to inject messages into a Low-power 1052 and Lossy Network can be used as a denial-of-service attack 1053 regardless of what forwarding protocol is used. For these reasons, 1054 Low-power and Lossy Networks typically employ link-layer security 1055 mechanisms to disable an attacker's ability to inject messages. 1057 To prevent attackers from injecting packets through an MPL Forwarder, 1058 the MPL Forwarder MUST NOT accept or forward MPL Data Messages from a 1059 communication interface that does not subscribe to the MPL Domain 1060 Address identified in message's destination address. 1062 MPL uses the Trickle algorithm to manage message transmissions and 1063 the security considerations described in [RFC6206] apply. 1065 14. References 1067 14.1. Normative References 1069 [I-D.ietf-6man-multicast-scopes] 1070 Droms, R., "IPv6 Multicast Address Scopes", draft-ietf- 1071 6man-multicast-scopes-02 (work in progress), November 1072 2013. 1074 [RFC1982] Elz, R. and R. Bush, "Serial Number Arithmetic", RFC 1982, 1075 August 1996. 1077 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 1078 Requirement Levels", BCP 14, RFC 2119, March 1997. 1080 [RFC2460] Deering, S. and R. Hinden, "Internet Protocol, Version 6 1081 (IPv6) Specification", RFC 2460, December 1998. 1083 [RFC2473] Conta, A. and S. Deering, "Generic Packet Tunneling in 1084 IPv6 Specification", RFC 2473, December 1998. 1086 [RFC2780] Bradner, S. and V. Paxson, "IANA Allocation Guidelines For 1087 Values In the Internet Protocol and Related Headers", BCP 1088 37, RFC 2780, March 2000. 1090 [RFC3307] Haberman, B., "Allocation Guidelines for IPv6 Multicast 1091 Addresses", RFC 3307, August 2002. 1093 [RFC4007] Deering, S., Haberman, B., Jinmei, T., Nordmark, E., and 1094 B. Zill, "IPv6 Scoped Address Architecture", RFC 4007, 1095 March 2005. 1097 [RFC4443] Conta, A., Deering, S., and M. Gupta, "Internet Control 1098 Message Protocol (ICMPv6) for the Internet Protocol 1099 Version 6 (IPv6) Specification", RFC 4443, March 2006. 1101 [RFC6206] Levis, P., Clausen, T., Hui, J., Gnawali, O., and J. Ko, 1102 "The Trickle Algorithm", RFC 6206, March 2011. 1104 [RFC6282] Hui, J. and P. Thubert, "Compression Format for IPv6 1105 Datagrams over IEEE 802.15.4-Based Networks", RFC 6282, 1106 September 2011. 1108 [RFC6550] Winter, T., Thubert, P., Brandt, A., Hui, J., Kelsey, R., 1109 Levis, P., Pister, K., Struik, R., Vasseur, JP., and R. 1110 Alexander, "RPL: IPv6 Routing Protocol for Low-Power and 1111 Lossy Networks", RFC 6550, March 2012. 1113 14.2. Informative References 1115 [RFC3973] Adams, A., Nicholas, J., and W. Siadak, "Protocol 1116 Independent Multicast - Dense Mode (PIM-DM): Protocol 1117 Specification (Revised)", RFC 3973, January 2005. 1119 [RFC4601] Fenner, B., Handley, M., Holbrook, H., and I. Kouvelas, 1120 "Protocol Independent Multicast - Sparse Mode (PIM-SM): 1121 Protocol Specification (Revised)", RFC 4601, August 2006. 1123 Authors' Addresses 1125 Jonathan W. Hui 1126 Cisco 1127 170 West Tasman Drive 1128 San Jose, California 95134 1129 USA 1131 Phone: +408 424 1547 1132 Email: jonhui@cisco.com 1134 Richard Kelsey 1135 Silicon Labs 1136 25 Thomson Place 1137 Boston, Massachusetts 02210 1138 USA 1140 Phone: +617 951 1225 1141 Email: richard.kelsey@silabs.com