idnits 2.17.1 draft-mirmin-bfd-extended-01.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 (July 2, 2019) is 1760 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) No issues found here. Summary: 0 errors (**), 0 flaws (~~), 1 warning (==), 1 comment (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 BFD Working Group G. Mirsky 3 Internet-Draft X. Min 4 Intended status: Standards Track ZTE Corp. 5 Expires: January 3, 2020 July 2, 2019 7 Extended Bidirectional Forwarding Detection 8 draft-mirmin-bfd-extended-01 10 Abstract 12 This document describes a mechanism to extend the capabilities of 13 Bidirectional Forwarding Detection (BFD). These extensions enable 14 BFD to measure performance metrics like packet loss and packet delay. 15 Also, a method to perform lightweight on-demand authentication is 16 defined in this specification. 18 Status of This Memo 20 This Internet-Draft is submitted in full conformance with the 21 provisions of BCP 78 and BCP 79. 23 Internet-Drafts are working documents of the Internet Engineering 24 Task Force (IETF). Note that other groups may also distribute 25 working documents as Internet-Drafts. The list of current Internet- 26 Drafts is at https://datatracker.ietf.org/drafts/current/. 28 Internet-Drafts are draft documents valid for a maximum of six months 29 and may be updated, replaced, or obsoleted by other documents at any 30 time. It is inappropriate to use Internet-Drafts as reference 31 material or to cite them other than as "work in progress." 33 This Internet-Draft will expire on January 3, 2020. 35 Copyright Notice 37 Copyright (c) 2019 IETF Trust and the persons identified as the 38 document authors. All rights reserved. 40 This document is subject to BCP 78 and the IETF Trust's Legal 41 Provisions Relating to IETF Documents 42 (https://trustee.ietf.org/license-info) in effect on the date of 43 publication of this document. Please review these documents 44 carefully, as they describe your rights and restrictions with respect 45 to this document. Code Components extracted from this document must 46 include Simplified BSD License text as described in Section 4.e of 47 the Trust Legal Provisions and are provided without warranty as 48 described in the Simplified BSD License. 50 Table of Contents 52 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 53 2. Conventions used in this document . . . . . . . . . . . . . . 2 54 2.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 2 55 2.2. Requirements Language . . . . . . . . . . . . . . . . . . 3 56 3. Extended BFD Control Message . . . . . . . . . . . . . . . . 3 57 3.1. Extended BFD Capability Negotiation . . . . . . . . . . . 4 58 3.2. Padding TLV . . . . . . . . . . . . . . . . . . . . . . . 6 59 3.3. Diagnostic TLV . . . . . . . . . . . . . . . . . . . . . 6 60 3.4. Performance Measurement with Extended BFD Control Message 7 61 3.5. Lightweight Authentication . . . . . . . . . . . . . . . 8 62 3.5.1. Lightweight Authentication Mode Negotiation . . . . . 9 63 3.5.2. Using Lightweight Authentication . . . . . . . . . . 10 64 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11 65 4.1. Extended BFD Message Types . . . . . . . . . . . . . . . 11 66 4.2. Lightweight Authentication Modes . . . . . . . . . . . . 12 67 4.3. Return Codes . . . . . . . . . . . . . . . . . . . . . . 12 68 5. Security Considerations . . . . . . . . . . . . . . . . . . . 13 69 6. Normative References . . . . . . . . . . . . . . . . . . . . 13 70 Appendix A. Acknowledgements . . . . . . . . . . . . . . . . . . 14 71 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 14 73 1. Introduction 75 [RFC5880] provided the base specification of Bidirectional Detection 76 (BFD) as the light-weight mechanism to monitor a path continuity 77 between two systems and detect a failure in the data-plane. Since 78 its introduction, BFD has been broadly deployed. There were several 79 attempts to introduce new capabilities in the protocol, some more 80 successful than others. One of the significant obstacles to 81 extending BFD capabilities may be seen in the compact format of the 82 BFD control message. This document introduces an Extended BFD 83 control message and describes the use of the new format for new BFD 84 capabilities. 86 2. Conventions used in this document 88 2.1. Terminology 90 BFD: Bidirectional Forwarding Detection 92 G-ACh Generic Associated Channel 94 HMAC Hashed Message Authentication Code 96 MTU Maximum Transmission Unit 97 PMTUD Path MTU Discovery 99 p2p: Point-to-Point 101 TLV Type, Length, Value 103 2.2. Requirements Language 105 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 106 "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and 107 "OPTIONAL" in this document are to be interpreted as described in BCP 108 14 [RFC2119] [RFC8174] when, and only when, they appear in all 109 capitals, as shown here. 111 3. Extended BFD Control Message 113 0 1 2 3 114 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 1 115 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 116 | | 117 | BFD Control Message | 118 | | 119 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 120 | Guard Word | 121 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 122 | | 123 ~ TLVs ~ 124 | | 125 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 127 Figure 1: Extended BFD Control Message Format 129 where fields are defined as the following: 131 o BFD control message as defined [RFC5880]. 133 o Guard word - four octets long field to identify the role of the 134 BFD system - sender or responder. 136 o TLVs - variable-length field that contains commands and/or data 137 encoded as type-length-value (TLV). 139 If an Extended BFD control message is encapsulated in IP/UDP, the 140 value of the Total Length in the IP header includes the length of the 141 Extended BFD control message while the value of the Length field of 142 the BFD control message equals the value as defined in [RFC5880]. If 143 an Extended BFD control message is to be used over Generic Associated 144 Channel (G-ACh), e.g., [RFC6428] new code point for G-ACh may be 145 allocated. 147 Figure 2 displays the generic TLV format. 149 0 1 2 3 150 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 1 151 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 152 | Type | Length | 153 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 154 ~ Value ~ 155 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 157 Figure 2: General Type-Length-Value Encoding 159 where fields are defined as the following: 161 o Type - two octets long field that defines the encoding of the 162 Value field 164 o Length - two octets long field equals length on the Value field in 165 octets. 167 o Value - depends on the Type. 169 TLVs may be included within other TLVs, in which case the former TLVs 170 are referred to as sub-TLVs. Sub-TLVs have independent types. 172 3.1. Extended BFD Capability Negotiation 174 A BFD system also referred to as a node in this document, that 175 supports Extended BFD first MUST discover whether other nodes in the 176 given BFD session support the Extended BFD. The node MUST send 177 Extended BFD control message initiating the Poll Sequence as defined 178 in [RFC5880]. If the remote system fails to respond with the 179 Extended BFD control message and the Final flag set, then the 180 initiator node MUST conclude that the BFD peer does not support the 181 use of the Extended BFD control messages. 183 The first Extended BFD control message initiating the Poll Sequence 184 SHOULD include the Capability TLV that lists capabilities that may be 185 used at some time during the lifetime of the BFD session. The format 186 of the Capability TLV and the capabilities that use the Extended BFD 187 control message are presented in Figure 3. 189 0 1 2 3 190 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 1 191 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 192 | Type = Capability | Length | 193 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 194 | L | D |M| Authentication ... | Reserved ... 195 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 197 Figure 3: Capability TLV Format 199 where fields are defined as the following: 201 o Type - TBA1 allocated by IANA in Section 4 203 o Length - two octets long field equals length on the Capability 204 field in octets. The value of the Length field MUST be a multiple 205 of 4. 207 o Loss - two bits size field. The least significant of two bits is 208 set if the node is capable of measuring packet loss using 209 periodically transmitted Extended BFD control message. The most 210 significant of two bits is set if the node is capable of measuring 211 packet loss using the Poll Sequence with Extended BFD control 212 message. 214 o Delay - two bits size field. The least significant of two bits is 215 set if the node is capable of measuring packet delay using 216 periodically transmitted Extended BFD control message. The most 217 significant of two bits is set if the node is capable of measuring 218 packet delay using the Poll Sequence with Extended BFD control 219 message. 221 o MTU- one-bit size field. Set if the node is capable of using the 222 Extended BFD control message in Path MTU Discovery (PMTUD). 223 [Ed.note: Definition of the PMTUD using the Extended BFD control 224 message is for further version.] 226 o (Lightweight) Authentication - variable-length field. The 227 Authentication field is used by a BFD system to advertise its 228 lightweight authentication capabilities. The format and the use 229 of the Authentication field are defined in Section 3.5.1. 231 o Reserved - MUST be zeroed on transmission and ignored on receipt. 232 The Reserved field is zero-padded to align the length of the 233 Capability TLV to a 4-octet boundary. 235 The remote BFD node that supports this specification MUST respond to 236 the Capability TLV with the Extended BFD control message that 237 includes the Capability TLV listing capabilities the responder 238 supports. The responder MUST set the Final flag in the Extended BFD 239 control message. 241 3.2. Padding TLV 243 Padding TLV MAY be used to generate Extended BFD control packets of 244 the desired length. 246 0 1 2 3 247 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 1 248 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 249 | Type = Padding | Length | 250 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 251 | | 252 ~ Padding ~ 253 | | 254 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 256 Figure 4: Padding TLV Format 258 where fields are defined as the following: 260 o Type - TBA1 allocated by IANA in Section 4 262 o Length - two octets long field equals length on the Padding field 263 in octets. 265 o Padding - variable-length field. MUST be zeroed on transmit and 266 ignored on receipt. 268 3.3. Diagnostic TLV 270 Diagnostic TLV MAY be used to characterize the result of the last 271 requested operation. 273 0 1 2 3 274 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 1 275 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 276 | Type = Diagnostic | Length | 277 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 278 | Return Code | Reserved | 279 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 281 Figure 5: Diagnostic TLV Format 283 where fields are defined as the following: 285 o Type - TBA6 allocated by IANA in Section 4. 287 o Length - MUST be set to four. 289 o Return Code - eight bits-long field. The responding BFD system 290 can set it to one of the values defined in Section 4.3. 292 o Reserved - 24 bits-long field. MUST be zeroed on transmit and 293 ignored on receipt. 295 3.4. Performance Measurement with Extended BFD Control Message 297 Loss measurement, delay measurement, and loss/delay measurement 298 messages can be used in the Extended BFD control message to support 299 one-way and round-trip measurements. All the messages are 300 encapsulated as TLVs with Type values allocated by IANA, Section 4. 302 The sender MAY use the Performance Metric TLV (presented in Figure 6) 303 to measure performance metrics and obtain the measurement report from 304 the receiver. 306 0 1 2 3 307 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 1 308 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 309 | Type = Performance Metric | Length | 310 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 311 | Loss Measurement Message, | 312 ~ Delay Measurement Mesage, or ~ 313 | Combined Loss/Delay Measurement Message | 314 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 316 Figure 6: Performance Metric TLV Format 318 where fields are defined as the following: 320 o Type - TBA3 through TBA5 allocated by IANA in Section 4 as 321 follows: 323 * TBA3 - Loss Measurement Type; 325 * TBA4 - Delay Measurement Type; 327 * TBA5 - Combined Loss/Delay Measurement Type 329 o Length - two octets long field equals length on the Metric sub- 330 TLVs field in octets. The value of the Length field MUST be a 331 multiple of 4. 333 o Value - various performance metrics measured either directly or 334 using synthetic methods accordingly using the messages defined in 335 Sections 3.1 through 3.3 [RFC6374]. 337 To perform one-way loss and/or delay measurement, the BFD node MAY 338 periodically transmit the Extended BFD message with one of the TLVs 339 listed above in Asynchronous mode. To perform synthetic loss 340 measurement, the sender MUST monotonically increment the counter of 341 transmitted test packets. Also, direct-mode loss measurement, as 342 described in [RFC6374], is supported. Procedures to negotiate and 343 manipulate transmission intervals defined in Sections 6.8.2 and 6.8.3 344 in [RFC5880] SHOULD be used to control the performance impact of 345 using the Extended BFD for performance measurement in the particular 346 BFD session. 348 To measure the round-trip loss and/or delay metrics the BFD node 349 transmits the Extended BFD control message with the Performance 350 Metric TLV with the Poll flag set. Before the transmission of the 351 Extended BFD control message with the Performance Metric TLV, the 352 receiver MUST clear the Poll flag and set the Final flag. 354 3.5. Lightweight Authentication 356 Using BFD without any security measures, for example, by exchanging 357 BFD control packets without authentication, increases the risk of an 358 attack, especially over multiple nodes. Thus, using BFD without 359 security measures may cause false positive as well as false negative 360 defect detection situations. In the former, an attacker may spoof 361 BFD control packets pretending to be a remote peer and can thus view 362 the BFD session operation even though the real path had failed. In 363 the latter, the attacker may spoof altered BFD control message 364 indicating that the BFD session is un-operational even though the 365 path and the remote BFD peer operate normally. 367 BFD technology[RFC5880] includes optional authentication protection 368 of BFD control packets to minimize the chances of attacks in a 369 networking system. However, at least some of the supported 370 authentication protocols do not provide sufficient protection in 371 modern networks. Also, current BFD technology requires 372 authentication of each and every BFD control packet. Such an 373 authentication requirement can put a computational burden on 374 networking devices, especially in the Asynchronous mode, at least 375 because authenticating each BFD control packet can require 376 substantial computing resources to support packet exchange at high 377 rates. 379 This specification defines a lightweight on-demand mode of 380 authentication for a BFD session. The lightweight authentication is 381 an optional mode that can be used when the BFD Authentication 382 [RFC5880] is not in use (bfd.AuthType is zero). The mechanism 383 includes negotiation (Section 3.5.1) and on-demand authentication 384 (Section 3.5.2) phases. During the former, BFD peers advertise 385 supported authentication capabilities and independently select the 386 commonly supported mode of the authentication. In the authentication 387 phase, each BFD system transmits, at certain events and periodically, 388 authenticated BFD control packets in Poll Sequence. 390 3.5.1. Lightweight Authentication Mode Negotiation 392 Figure 7 displays the format of the Authentication field that is part 393 of the Capability Encoding: 395 0 1 2 3 396 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 1 397 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 398 | Len | AuthL | Authentication Mode ... 399 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 401 Figure 7: Lightweight Authentication Capability Field Format 403 where fields are defined as the following: 405 o Len (Length) - four-bits long field. The value of the Length 406 field is equal to the length of the Authentication field, 407 including the Length, in octets. 409 o AuthL (Authentication Length) - four bits size field. The value 410 of the field is, in four octets long words, the longest 411 authentication signature the BFD system is capable of supporting 412 for any of the methods advertised in the AuthMode field. 414 o Authentication Mode - variable-length field. It is a bit-coded 415 field that a BFD system uses to list modes of lightweight 416 authentication it supports. 418 A BFD system uses Capability TLV, defined in Section 3.1, to discover 419 the commonly supported mode of the Lightweight Authentication. The 420 system sets the values in the Authentication field according to 421 properly reflect its authentication capabilities. The BFD system 422 transmits the Extended BFD control packet with Capability TLV as the 423 first in a Poll Sequence. The remote BFD system that supports this 424 specification receives the Extended BFD control packet with the 425 advertised Lightweight Authentication modes and stores information 426 locally. The system responds with the advertisement of its 427 Lightweight Authentication capabilities in the Extended BFD control 428 packet with the Final flag set. Each BFD system uses local and 429 received information about Lightweight Authentication capabilities to 430 deduce the commonly supported modes and selects from that set the one 431 that uses the strongest authentication with the longest signature. 432 If the common set is empty, i.e., none of supported by one BFD system 433 authentication method is supported by another, an implementation MUST 434 reflect this in its operational state and SHOULD notify an operator. 436 3.5.2. Using Lightweight Authentication 438 After BFD peers select an authentication mode for using in 439 Lightweight Authentication each BFD system MUST use it to 440 authenticate each Extended BFD control packet transmitted as part of 441 a Poll Sequence using Lightweight Authentication TLV presented in 442 Figure 8. 444 0 1 2 3 445 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 1 446 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 447 |Type=Lightweight Authentication| Length | 448 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 449 | | 450 ~ HMAC ~ 451 | | 452 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 454 Figure 8: Lightweight Authentication TLV Format 456 where fields are defined as the following: 458 o Type - TBA8 allocated by IANA in Section 4 460 o Length - two octets long field equals length on the HMAC (Hashed 461 Message Authentication Code) field in octets. The value of the 462 Length field MUST be a multiple of 4. 464 o HMAC - the hash value calculated on the preceding Extended BFD 465 control packet data. 467 The Lightweight Authentication TLV MUST be the last TLV in an 468 Extended BFD control packet. Padding TLV (Section 3.2) MAY be used 469 to align the length of the Extended BFD control packet, excluding the 470 Lightweight Authentication TLV, at multiple of 16 boundary. 472 The BFD system that receives the Extended BFD control packet with the 473 Lightweight Authentication TLV MUST first validate the 474 .authentication by calculating the hash over the Extended BFD control 475 packet. If the validation succeeds, the receiver MUST transmit the 476 Extended BFD control packet with the Final flag set and the value of 477 the Return code field in Diagnostic TLV set to None value (Table 5). 478 If the validation of the lightweight authentication fails, then the 479 BFD system MUST transmit the Extended BFD control packet with the 480 Final flag set and the value of the Return Code field of the 481 Diagnostic TLV set to Lightweight Authentication failed value 482 (Table 5). The BFD system MUST have a control policy that defines 483 actions when the system receives the Lightweight Authentication 484 failed return code. 486 4. IANA Considerations 488 4.1. Extended BFD Message Types 490 IANA is requested to create the Extended BFD Message Types registry. 491 All code points in the range 1 through 32759 in this registry shall 492 be allocated according to the "IETF Review" procedure as specified in 493 [RFC8126]. Code points in the range 32760 through 65279 in this 494 registry shall be allocated according to the "First Come First 495 Served" procedure as specified in [RFC8126]. Remaining code points 496 are allocated according to Table 1: 498 +---------------+-------------------------+-------------------------+ 499 | Value | Description | Reference | 500 +---------------+-------------------------+-------------------------+ 501 | 0 | Reserved | This document | 502 | 1- 32767 | Mandatory TLV, | IETF Review | 503 | | unassigned | | 504 | 32768 - 65279 | Optional TLV, | First Come First Served | 505 | | unassigned | | 506 | 65280 - 65519 | Experimental | This document | 507 | 65520 - 65534 | Private Use | This document | 508 | 65535 | Reserved | This document | 509 +---------------+-------------------------+-------------------------+ 511 Table 1: Extended BFD Type Registry 513 This document defines the following new values in Extended BFD Type 514 registry: 516 +-------+---------------------------------+---------------+ 517 | Value | Description | Reference | 518 +-------+---------------------------------+---------------+ 519 | TBA1 | Padding | This document | 520 | TBA2 | Capability | This document | 521 | TBA3 | Loss Measurement | This document | 522 | TBA4 | Delay Measurement | This document | 523 | TBA5 | Combined Loss/Delay Measurement | This document | 524 | TBA6 | Diagnostic | This document | 525 | TBA8 | Lightweight Authentication | This document | 526 +-------+---------------------------------+---------------+ 528 Table 2: Extended BFD Types 530 4.2. Lightweight Authentication Modes 532 IANA is requested to create a Lightweight Authentication Modes 533 registry. All code points in this registry shall be allocated 534 according to the "IETF Review" procedure as specified in [RFC8126]. 536 This document defines the following new values in the Lightweight 537 Authentication Modes registry: 539 +--------------+-------+------------------------+---------------+ 540 | Bit Position | Value | Description | Reference | 541 +--------------+-------+------------------------+---------------+ 542 | 0 | 0x1 | Keyed SHA-1 | This document | 543 | 1 | 0x2 | Meticulous Keyed SHA-1 | This document | 544 | 2 | 0x4 | SHA-256 | This document | 545 +--------------+-------+------------------------+---------------+ 547 Table 3: Lightweight Authentication Modes 549 4.3. Return Codes 551 IANA is requested to create the Extended BFD Return Codes registry. 552 All code points in the range 1 through 250 in this registry shall be 553 allocated according to the "IETF Review" procedure as specified in 554 [RFC8126]. Remaining code points are allocated according to Table 4: 556 +---------+--------------+---------------+ 557 | Value | Description | Reference | 558 +---------+--------------+---------------+ 559 | 0 | Reserved | This document | 560 | 1- 250 | Unassigned | IETF Review | 561 | 251-253 | Experimental | This document | 562 | 254 | Private Use | This document | 563 | 255 | Reserved | This document | 564 +---------+--------------+---------------+ 566 Table 4: Extended BFD Return Codes Registry 568 This document defines the following new values in Extended BFD Return 569 Codes registry: 571 +-------+-------------------------------------+---------------+ 572 | Value | Description | Reference | 573 +-------+-------------------------------------+---------------+ 574 | 0 | None | This document | 575 | 1 | One or more TLVs was not understood | This document | 576 | 2 | Lightweight Authentication failed | This document | 577 +-------+-------------------------------------+---------------+ 579 Table 5: Extended BFD Return Codes 581 5. Security Considerations 583 This document does not introduce new security aspects but inherits 584 all security considerations from [RFC5880], [RFC6428], and [RFC6374]. 586 6. Normative References 588 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 589 Requirement Levels", BCP 14, RFC 2119, 590 DOI 10.17487/RFC2119, March 1997, 591 . 593 [RFC5880] Katz, D. and D. Ward, "Bidirectional Forwarding Detection 594 (BFD)", RFC 5880, DOI 10.17487/RFC5880, June 2010, 595 . 597 [RFC6374] Frost, D. and S. Bryant, "Packet Loss and Delay 598 Measurement for MPLS Networks", RFC 6374, 599 DOI 10.17487/RFC6374, September 2011, 600 . 602 [RFC6428] Allan, D., Ed., Swallow, G., Ed., and J. Drake, Ed., 603 "Proactive Connectivity Verification, Continuity Check, 604 and Remote Defect Indication for the MPLS Transport 605 Profile", RFC 6428, DOI 10.17487/RFC6428, November 2011, 606 . 608 [RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for 609 Writing an IANA Considerations Section in RFCs", BCP 26, 610 RFC 8126, DOI 10.17487/RFC8126, June 2017, 611 . 613 [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 614 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, 615 May 2017, . 617 Appendix A. Acknowledgements 619 TBD 621 Authors' Addresses 623 Greg Mirsky 624 ZTE Corp. 626 Email: gregimirsky@gmail.com 628 Xiao Min 629 ZTE Corp. 631 Email: xiao.min2@zte.com.cn