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Please use uppercase 'NOT' together with RFC 2119 keywords (if that is what you mean). Found 'MUST not' in this paragraph: Routing resource capabablity sent in DIO message has link local scope and it MUST not be forwarded. The 'C' bit of this capability MUST be set to 0. -- The document date (June 3, 2020) is 1423 days in the past. Is this intentional? 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Jadhav, Ed. 3 Internet-Draft Huawei 4 Intended status: Standards Track P. Thubert 5 Expires: December 5, 2020 Cisco 6 M. Richardson 7 Sandelman Software Works 8 R. Sahoo 9 Juniper 10 June 3, 2020 12 RPL Capabilities 13 draft-ietf-roll-capabilities-06 15 Abstract 17 This draft enables the discovery, advertisement and query of 18 capabilities for RPL nodes. 20 Status of This Memo 22 This Internet-Draft is submitted in full conformance with the 23 provisions of BCP 78 and BCP 79. 25 Internet-Drafts are working documents of the Internet Engineering 26 Task Force (IETF). Note that other groups may also distribute 27 working documents as Internet-Drafts. The list of current Internet- 28 Drafts is at https://datatracker.ietf.org/drafts/current/. 30 Internet-Drafts are draft documents valid for a maximum of six months 31 and may be updated, replaced, or obsoleted by other documents at any 32 time. It is inappropriate to use Internet-Drafts as reference 33 material or to cite them other than as "work in progress." 35 This Internet-Draft will expire on December 5, 2020. 37 Copyright Notice 39 Copyright (c) 2020 IETF Trust and the persons identified as the 40 document authors. All rights reserved. 42 This document is subject to BCP 78 and the IETF Trust's Legal 43 Provisions Relating to IETF Documents 44 (https://trustee.ietf.org/license-info) in effect on the date of 45 publication of this document. Please review these documents 46 carefully, as they describe your rights and restrictions with respect 47 to this document. Code Components extracted from this document must 48 include Simplified BSD License text as described in Section 4.e of 49 the Trust Legal Provisions and are provided without warranty as 50 described in the Simplified BSD License. 52 Table of Contents 54 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 55 1.1. Requirements Language and Terminology . . . . . . . . . . 3 56 1.2. What are Capabilities? . . . . . . . . . . . . . . . . . 4 57 2. Requirements for this document . . . . . . . . . . . . . . . 4 58 2.1. How are Capabilities different from existing RPL 59 primitives? . . . . . . . . . . . . . . . . . . . . . . . 4 60 3. Capabilities . . . . . . . . . . . . . . . . . . . . . . . . 5 61 3.1. Capability Control Message Option . . . . . . . . . . . . 5 62 3.2. Capabilities Handshake . . . . . . . . . . . . . . . . . 6 63 4. Querying Capabilities . . . . . . . . . . . . . . . . . . . . 6 64 4.1. Capability Query (CAPQ) . . . . . . . . . . . . . . . . . 6 65 4.1.1. Capability Type List Control Option . . . . . . . . . 7 66 4.1.2. Secure CAPQ . . . . . . . . . . . . . . . . . . . . . 7 67 4.1.3. Base rules for CAPQ handling . . . . . . . . . . . . 7 68 4.2. Capability Set Response (CAPS) . . . . . . . . . . . . . 7 69 4.2.1. Secure CAPS . . . . . . . . . . . . . . . . . . . . . 8 70 5. Guidelines for defining new capabilities . . . . . . . . . . 8 71 5.1. Handling Capability flags . . . . . . . . . . . . . . . . 8 72 5.1.1. Rules to handle capabilities flag . . . . . . . . . . 9 73 6. Node Capabilities . . . . . . . . . . . . . . . . . . . . . . 9 74 6.1. Capability Indicators . . . . . . . . . . . . . . . . . . 9 75 6.1.1. Format of Capability Indicators . . . . . . . . . . . 9 76 6.2. Routing Resource Capability . . . . . . . . . . . . . . . 9 77 6.2.1. Format of Routing Resource Capability . . . . . . . . 10 78 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 10 79 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11 80 8.1. New option: Capabilities . . . . . . . . . . . . . . . . 11 81 8.2. Capability Sub-Type . . . . . . . . . . . . . . . . . . . 11 82 8.3. New Registry for CAPQ Flags . . . . . . . . . . . . . . . 12 83 8.4. New Registry for Capabilities Flags . . . . . . . . . . . 12 84 8.5. New Registry for Capabilities Indicators . . . . . . . . 12 85 9. Security Considerations . . . . . . . . . . . . . . . . . . . 13 86 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 13 87 10.1. Normative References . . . . . . . . . . . . . . . . . . 13 88 10.2. Informative References . . . . . . . . . . . . . . . . . 13 89 Appendix A. Capability Handshake Example . . . . . . . . . . . . 14 90 A.1. Query supported Cap Types . . . . . . . . . . . . . . . . 14 91 A.2. Query specific Cap Set . . . . . . . . . . . . . . . . . 14 92 A.3. CAPS with partial Cap Set . . . . . . . . . . . . . . . . 15 93 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 16 95 1. Introduction 97 RPL [RFC6550] specifies a proactive distance-vector based routing 98 scheme. The protocol creates a DAG-like structure which operates 99 with a given "Mode of Operation" (MOP) determining the minimal and 100 mandatory set of primitives to be supported by all the participating 101 nodes. 103 This document adds a notion of capabilities using which nodes in the 104 network could inform its peers about its additional capabilities. 105 This document highlights the differences of capabilities from that of 106 Mode of operation and explains the necessity of it. 108 1.1. Requirements Language and Terminology 110 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 111 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 112 document are to be interpreted as described in RFC 2119 [RFC2119]. 114 MOP: Mode of Operation. Identifies the MOP of the RPL Instance as 115 administratively provisioned at and distributed by the DODAG root. 117 MOPex: Extended MOP: As defined in [I-D.ietf-roll-mopex]. 119 Capabilities: Additional features or capabilities that are supported 120 by the node. 122 Cap: Abbreviated term used for Capability. 124 Caps: Abbreviated term used for Capabilities. 126 DAO: DODAG Advertisement Object. An RPL message used to advertise 127 the target information in order to establish routing adjacencies. 129 DIO: DODAG Information Object. An RPL message initiated by the root 130 and is used to advertise the network configuration information. 132 Current parent: Parent 6LR node before switching to the new path. 134 NPDAO: No-Path DAO. A DAO message which has target with lifetime 0. 136 Upstream path/direction: Path or direction from the node to the Root 137 in a DAG. 139 Downstream path/direction: Path or direction to the node from the 140 Root in a DAG. 142 This document uses terminology described in [RFC6550]. For the sake 143 of readability all the known relevant terms are repeated in this 144 section. 146 1.2. What are Capabilities? 148 Currently RPL specification does not have a mechanism whereby a node 149 can signal the set of features that are available on its end. Such a 150 mechanism could help the root to advertise its capabilities and in 151 response also determine some advanced information about the 152 capabilities of the joining nodes. This document defines 153 Capabilities which could be supported by the nodes and handshaked as 154 part of RPL signaling. Capabilities are embedded as an RPL Control 155 Message Option as defined in Section 6.7 of [RFC6550]. 157 2. Requirements for this document 159 Following are the requirements considered for this documents: 161 REQ1: Backwards compatibility. The new options and new fields in 162 the DIO message should be backward compatible i.e. if there 163 are nodes which support old MOPs they could still operate in 164 their own instances. 166 REQ2: Optional capabilities handshake. Capabilities are features, 167 possibly optional, which could be handshaked between the nodes 168 and the root within an RPL Instance. 170 REQ3: Capabilities handshake could be optionally added with existing 171 MOPs. Capabilities been optional in nature could be put to 172 use with existing MOPs. Capabilities and MOP-extension is 173 mutually independent i.e. a DIO can have a capabilities 174 option, MOP-extension option or both in the same message. 176 REQ4: Capabilities could be explicitly queried. 178 2.1. How are Capabilities different from existing RPL primitives? 180 The Mode of Operation (MOP) field in RPL mandates the operational 181 requirement for the nodes joining as routers. MOP and DIO 182 Configuration Option is strictly controlled by the Root node in RPL. 183 Intermediate 6LRs cannot modify these fields. Also, the MOP never 184 changes for the lifetime of the RPL Instance. Changes in DIO 185 Configuration Option are possible but are rare. Capabilities, on the 186 other hand, might change more dynamically. 188 RPL DIO message also carries routing metrics and constraints as 189 specified in [RFC6551]. Metrics and constraints are used as part of 190 objective function which aids in node's rank calculation. A router 191 may use capabilities carried in DIO message as additional metrics/ 192 constraints. However, capabilities have a larger scope and may be 193 carried in other messages other than DIO and can flow in both the 194 directions (upstream and downstream). 196 3. Capabilities 198 Handling of Capabilities MUST be supported if the network uses MOPex 199 [I-D.ietf-roll-mopex]. 201 Note that capabilities and MOPex are mutually exclusive and it is 202 possible for an implementation to support either or both of the 203 options. 205 3.1. Capability Control Message Option 207 0 1 2 3 208 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 1 209 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 210 | Type = TODO | Option Length | Capabilities TLVs 211 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 213 Figure 1: Capabilities Option 215 Multiple capabilities could be sent in the same message. The length 216 field allows the message parser to skip the capability TLV parsing. 218 0 1 2 3 219 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 1 220 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 221 | CapType | Len |J|I|C| Flags | ... 222 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 224 Figure 2: Capabilities TLV 226 Every capability is identified by its type and it may have an 227 optional Capability Info. Note that a given capability may or may 228 not be diseminated with additional information depending on the scope 229 of the capability indicated by the I bit. 231 Len: 8-bit unsigned integer, representing the length in octets of the 232 TLV, not including the CapType, Length and Flags fields. 234 J = Join only as leaf if capability not understood. 236 I = Ignore the message if this capability is not understood. 238 C = Flag indicating that the capability MUST be copied in the 239 downstream message. 241 3.2. Capabilities Handshake 243 The root node could advertise the set of capabilities it supports in 244 the DIO message. A node could take advantage of the knowledge that 245 the root supports a particular capability. Similarly a node could 246 advertise its capabilities in the DAO message using the capability 247 control message option defined in this document. Capabilities 248 advertised by non-root nodes are strictly a subset of the 249 capabilities advertised by the root. 251 In storing MOP, the DAO message from the 6LR could contain multiple 252 target options because of the DAO-Aggregation. The targets of the 253 capabilities option are indicated by one or more Target options that 254 precede the Capabilities Option. This handling is similar to the 255 Transit Information Option as supported in Section 6.7.8. of 256 [RFC6550]. 258 4. Querying Capabilities 260 Nodes may be interested in knowing the capabilities of another node 261 before taking an action. For e.g., Consider 262 [I-D.ietf-roll-dao-projection], the Root may want to know the 263 capabilities of the nodes along a network segment before it initiates 264 a projected DAO to install the routes along that segment. 266 Caps can be carried in existing RPL Control messages as Control 267 Options, however Caps can also be queried explicitly. This section 268 provides a way for a node to query capability set of another node. 269 The capability query and subsequent response messages are directly 270 addressed between the two peers. 272 4.1. Capability Query (CAPQ) 274 0 1 2 3 275 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 1 276 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 277 | RPLInstanceID | Flags | reserved | CAPQSequence | 278 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 279 | Option(s)... 280 +-+-+-+-+-+-+-+-+ 282 Figure 3: CAPQ base object 284 CAPQSequence: One byte, Sequence number sent by the CAPQ sender 285 which is reflected back by the responder in the CAPS message. 287 Flags: One byte, set to zero by sender, ignored by receiver. 289 reserved: One byte, set to zero by sender, ignored by receiver. 291 CAPQ base object may be followed by one or more options. The 292 Capability Type List Control Option Figure 4 is used to carry a set 293 of capability types to query about. 295 If the sender does not send Figure 4 option, this would indicate that 296 the node intends to query the capability type list Figure 4 supported 297 by the target node. 299 4.1.1. Capability Type List Control Option 301 0 1 2 3 302 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 1 303 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 304 | Type = TODO | Option Length | CapType1 | CapType2 | 305 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 306 | CapType3 | ..... 307 +-+-+-+-+-+-+-+-+-+-+-+-+ 309 Figure 4: Capability Type List Control Option 311 4.1.2. Secure CAPQ 313 A Secure CAPQ message follows the format in [RFC6550] Figure 7, where 314 the base message format is the CAPQ message shown in Figure 3. 316 4.1.3. Base rules for CAPQ handling 318 A CAPQ message may get dropped or lost in the transit. The sender of 319 CAPQ MAY retry the CAPQ message after some delay. The delay SHOULD 320 NOT be less than 1 second. 322 4.2. Capability Set Response (CAPS) 324 0 1 2 3 325 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 1 326 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 327 | RPLInstanceID | Flags | Reserved | CAPQSequence | 328 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 329 | Option(s)... 330 +-+-+-+-+-+-+-+-+ 332 Figure 5: CAPS base object 334 Flags: One byte, set to zero by sender, ignored by receiver. 336 reserved: One byte, set to zero by sender, ignored by receiver. 338 CAPQSequence: One byte, Sequence number copied from CAPQSequence 339 received in the CAPQ message. 341 CAPS message SHOULD contain the capability set Figure 1 queried by 342 the CAPQ sender. If the target node does not support subset of the 343 queried capabilities then the Figure 4 option with the unsupported 344 cap-types SHOULD be sent back indicating the queried capabilities 345 not-supported by the target node. For an example, check Appendix A.3 347 If the CAPQ message does not contain any Figure 4 option then the 348 receiver MUST respond with the cap types it supports using Figure 4. 350 If the capability set cannot be transmitted in a single message (for 351 e.g., because of MTU limitations) then multiple CAPS messages could 352 be used. All the CAPS message MUST use the same CAPQSequence number 353 copied from the corresponding CAPQ message. 355 4.2.1. Secure CAPS 357 A Secure CAPS message follows the format in [RFC6550] Figure 7, where 358 the base message format is the CAPS message shown in Figure 5. 360 5. Guidelines for defining new capabilities 362 This section provides guidelines/recommendations towards defining new 363 capabilities. Note that the capabilities might be carried as part of 364 the multicast messaging such as DIO and hence the set should be used 365 in restrictive manner as far as possible. 367 5.1. Handling Capability flags 369 A node MUST drop or discard the message with an unknown capability 370 with 'D' flag set. The message MUST be discarded silently. 372 The 'J' (join) flag can be set in context to a capability either by a 373 6LR or the root. The 'J' flag indicates that if the capability is 374 not supported by a node then it can join the instance only as a 6LN 375 (or do not join as 6LR). 377 The 'C' (copy) flag is set by the node indicating that the 378 capabilities MUST be copied downstream by the node even if the node 379 does not understand the capability. 381 5.1.1. Rules to handle capabilities flag 382 On receiving a capability it does not support, the node MUST check 383 the 'J' flag of the capability before joining the Instance. If the 384 'J' flag is set then it can only join as a 6LN. 385 If the node is operating as 6LR and subsequently it receives a 386 capability from its preferred parent which it does not understand 387 with 'J' flag set, then the node has to switch itself to 6LN mode. 388 During switching the node needs to inform its downstream peers of its 389 changed status by sending a DIO with infinite rank as mentioned in 390 RFC6550. Alternatively, a node may decide to switch to another 391 parent with compatible and known capabilities. 392 Capabilities are used to indicate a feature that is supported by the 393 node. Capabilities are not meant for configuration management for 394 e.g., setting a threshold. 396 6. Node Capabilities 398 6.1. Capability Indicators 400 Capability Indicators indicates the capabilities supported by the 401 node in the form of simple flags. Capabilities who do not have 402 additional information to be specified could make use of these flags 403 to indicate their support. 405 6.1.1. Format of Capability Indicators 407 0 1 2 3 408 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 1 409 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 410 | CapType=0x01 | Len |J|I|C| Flags |T|..Indicators.. 411 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 413 Figure 6: Capability Indicators TLV 415 Flags: LRs MUST set it to 0. I bit will always be set to 0. 417 T flag (Bit 1): Indicates whether the node supports 6LoRH [RFC8138]. 419 6.2. Routing Resource Capability 421 Storing mode of operation requires each intermediate router in the 422 LLN to maintain routing states' information in the routing table. 423 LLN routers typically operate with constraints on processing power, 424 memory, and energy (battery power). Memory limits the number of 425 routing states an LR and BR can maintain. When the routing table of 426 an LR or BR is full, it will either reject the new DAO messages 427 received or will use some replacement policy to remove a routing 428 entry and add the new one. Rejection of DAO messages will lead to an 429 increase in DAO message transmission that impacts the energy and 430 network convergence time. Routing state replacement leads to 431 downward path downtime. 433 One possible way to solve problems due to routing table size 434 constraint is to use this information to add neighbors to the DAO 435 parent set. Routing resource capability can be used by LR and BR to 436 advertise their current routing table usage details in the network. 437 LR or LNs in LLN can use this information in the selection of the DAO 438 parent set. PCE can use this information to select intermediate 439 routers for the projected routes. Routing Resource is an optional 440 capability. 442 Routing resource capabablity sent in DIO message has link local scope 443 and it MUST not be forwarded. The 'C' bit of this capability MUST be 444 set to 0. 446 6.2.1. Format of Routing Resource Capability 448 0 1 2 3 449 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 1 450 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 451 | CapType=0x02 | Len=3 |J|I|C| Flags | Reserved | 452 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 453 | Total Capacity | 454 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 456 Figure 7: Routing Resource Capability TLV 458 Type: 0x02. 460 Flags: I bit MUST be set to 0. C bit MUST be set to 0. 462 Len: 8-bit unsigned integer, representing the length in octets of the 463 option, not including the Option Type and Length/flags fields. 465 Resvd: 8-bit unused field. It MUST be initialized to zero by the 466 sender and MUST be ignored by the receiver. 468 Total Capacity: 16 bit unsigned integer representing the routing 469 table size. 471 7. Acknowledgements 473 Thanks to Georgios Papadopoulos, Li Zhao for early review and 474 feedback. 476 8. IANA Considerations 478 IANA is requested to allocate new codes for the CAPQ and CAPS 479 messages from the RPL Control Codes registry. 481 +------+----------------------------+---------------+ 482 | Code | Description | Reference | 483 +------+----------------------------+---------------+ 484 | TBD1 | Capability Query | This document | 485 | TBD2 | Capability Response | This document | 486 | TBD3 | Secure Capability Query | This document | 487 | TBD4 | Secure Capability Response | This document | 488 +------+----------------------------+---------------+ 490 New RPL Control Messages 492 The MSB of the codes allocated to "Secure" messages above should be 493 set. 495 8.1. New option: Capabilities 497 New entry is required for supporting new Capabilities option and new 498 Capability Type List Option in the "RPL Control Message Options" 499 space [RFC6550]. 501 +-------+-----------------------------+---------------+ 502 | Value | Meaning | Reference | 503 +-------+-----------------------------+---------------+ 504 | TODO | Capability Option | This document | 505 | TODO | Capability Type List Option | This document | 506 +-------+-----------------------------+---------------+ 508 New options 510 8.2. Capability Sub-Type 512 IANA is requested to create a registry for the Capabilities Type as 513 described in Figure 2 of this document. This registry should be 514 located in TODO. New Capabilities types may be allocated only by an 515 IETF review. 517 +-------+-----------------------------+---------------+ 518 | Value | Meaning | Reference | 519 +-------+-----------------------------+---------------+ 520 | 0x01 | Capability Indicators | This document | 521 | 0x02 | Routing Resource Capability | This document | 522 +-------+-----------------------------+---------------+ 524 Type 526 8.3. New Registry for CAPQ Flags 528 IANA is requested to create a registry for the Capabilities flags as 529 described in Section 4.1 of this document. This registry should be 530 located in TODO. New Capabilities flags may be allocated only by an 531 IETF review. Currently no flags are defined by this document. Each 532 value is tracked with the following qualities: 534 o Flag 536 o Description 538 o Defining RFC 540 8.4. New Registry for Capabilities Flags 542 IANA is requested to create a registry for the Capabilities flags as 543 described in Section 2.1 of this document. This registry should be 544 located in TODO. New Capabilities flags may be allocated only by an 545 IETF review. Currently no flags are defined by this document. Each 546 value is tracked with the following qualities: 548 o Flag 550 o Description 552 o Defining RFC 554 8.5. New Registry for Capabilities Indicators 556 IANA is requested to create a registry for the Capabilities 557 Indicators as described in Section 6.1 of this document. This 558 registry should be located in TODO. New Capabilities indicators may 559 be allocated only by an IETF review. Each value is tracked with the 560 following qualities: 562 o Flag 564 o Description 565 o Defining RFC 567 9. Security Considerations 569 The options defined in this document are carried in the base message 570 objects as defined in [RFC6550]. The RPL control message options are 571 protected by the same security mechanisms that protect the base 572 messages. 574 Capabilities flag can reveal that the node has been upgraded or is 575 running a old feature set. This document assumes that the base 576 messages that carry these options are protected by RPL security 577 mechanisms and thus are not visible to a malicious node. 579 [TODO] implications of malicious attack involving setting the 580 capability flags. 582 10. References 584 10.1. Normative References 586 [I-D.ietf-roll-mopex] 587 Jadhav, R., Thubert, P., and M. Richardson, "Mode of 588 Operation extension", draft-ietf-roll-mopex-00 (work in 589 progress), April 2020. 591 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 592 Requirement Levels", BCP 14, RFC 2119, 593 DOI 10.17487/RFC2119, March 1997, 594 . 596 [RFC6550] Winter, T., Ed., Thubert, P., Ed., Brandt, A., Hui, J., 597 Kelsey, R., Levis, P., Pister, K., Struik, R., Vasseur, 598 JP., and R. Alexander, "RPL: IPv6 Routing Protocol for 599 Low-Power and Lossy Networks", RFC 6550, 600 DOI 10.17487/RFC6550, March 2012, 601 . 603 [RFC8138] Thubert, P., Ed., Bormann, C., Toutain, L., and R. Cragie, 604 "IPv6 over Low-Power Wireless Personal Area Network 605 (6LoWPAN) Routing Header", RFC 8138, DOI 10.17487/RFC8138, 606 April 2017, . 608 10.2. Informative References 610 [I-D.ietf-lwig-nbr-mgmt-policy] 611 Jadhav, R., Sahoo, R., Duquennoy, S., and J. Eriksson, 612 "Neighbor Management Policy for 6LoWPAN", draft-ietf-lwig- 613 nbr-mgmt-policy-03 (work in progress), February 2019. 615 [I-D.ietf-roll-dao-projection] 616 Thubert, P., Jadhav, R., and M. Gillmore, "Root initiated 617 routing state in RPL", draft-ietf-roll-dao-projection-10 618 (work in progress), May 2020. 620 [I-D.thubert-roll-turnon-rfc8138] 621 Thubert, P. and L. Zhao, "Configuration option for RFC 622 8138", draft-thubert-roll-turnon-rfc8138-03 (work in 623 progress), July 2019. 625 [RFC6551] Vasseur, JP., Ed., Kim, M., Ed., Pister, K., Dejean, N., 626 and D. Barthel, "Routing Metrics Used for Path Calculation 627 in Low-Power and Lossy Networks", RFC 6551, 628 DOI 10.17487/RFC6551, March 2012, 629 . 631 Appendix A. Capability Handshake Example 633 A.1. Query supported Cap Types 635 Root 6LR/6LN 636 | | 637 | CAPQ(seq=1, opts=nil) | 638 |---------------------------------->| 639 | | 640 | | 641 | CAPS(seq=1, opts={CapTypeList}) | 642 |<----------------------------------| 643 | | 645 Figure 8: Query supported Cap Types 647 CAPQ message with no CapTypeList Option results in the peer 648 responding with a CAPS message with CapTypeList Option indicating all 649 the capability set it supports. 651 A.2. Query specific Cap Set 652 Root 6LR/6LN 653 | | 654 | CAPQ(seq=2, | 655 | opts={CapTypeList=[Cap1, Cap2]})| 656 |---------------------------------->| 657 | | 658 | | 659 | CAPS(seq=2, | 660 | opts={Cap1=Cap1Value, | 661 | Cap2=Cap2Value}) | 662 |<----------------------------------| 663 | | 665 Figure 9: Query specific Cap Set 667 This flow indicates the case where the Root probes for specific 668 Capabilities of the peer node and the peer node responds with the 669 value of indicated Capability set. 671 A.3. CAPS with partial Cap Set 673 Root 6LR/6LN 674 | | 675 | CAPQ(seq=3, | 676 | opts={CapTypeList=[Cap1, Cap2, | 677 | Cap3, Cap4]})| 678 |---------------------------------->| 679 | | 680 | | 681 | CAPS(seq=3, | 682 | opts={Cap2=Cap2Value, | 683 | Cap3=Cap3Value, | 684 | CapTypeList=[Cap1,Cap4]})| 685 |<----------------------------------| 686 | | 688 Partial Capability Set handshake 690 Assume that Root queries for capabilities {Cap1, Cap2, Cap3, Cap4} 691 from the peer node. However the peer node does not support or does 692 not understand capability {cap1, cap4}. In this case the peer node 693 will respond back with value of Cap2 and Cap3 (which it understands) 694 and set the CapTypeList option with {Cap1, Cap4} type. 696 Authors' Addresses 698 Rahul Arvind Jadhav (editor) 699 Huawei 700 Kundalahalli Village, Whitefield, 701 Bangalore, Karnataka 560037 702 India 704 Phone: +91-080-49160700 705 Email: rahul.ietf@gmail.com 707 Pascal Thubert 708 Cisco Systems, Inc 709 Building D 710 45 Allee des Ormes - BP1200 711 MOUGINS - Sophia Antipolis 06254 712 France 714 Phone: +33 497 23 26 34 715 Email: pthubert@cisco.com 717 Michael Richardson 718 Sandelman Software Works 720 Email: mcr+ietf@sandelman.ca 722 Rabi Narayan Sahoo 723 Juniper 725 Email: rabinarayans0828@gmail.com