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Checking references for intended status: Proposed Standard ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) -- Obsolete informational reference (is this intentional?): RFC 2845 (Obsoleted by RFC 8945) Summary: 0 errors (**), 0 flaws (~~), 1 warning (==), 2 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Network Working Group W. Kumari 3 Internet-Draft Google 4 Intended status: Standards Track E. Hunt 5 Expires: June 20, 2020 ISC 6 R. Arends 7 ICANN 8 W. Hardaker 9 USC/ISI 10 D. Lawrence 11 Oracle + Dyn 12 December 18, 2019 14 Extended DNS Errors 15 draft-ietf-dnsop-extended-error-13 17 Abstract 19 This document defines an extensible method to return additional 20 information about the cause of DNS errors. Though created primarily 21 to extend SERVFAIL to provide additional information about the cause 22 of DNS and DNSSEC failures, the Extended DNS Errors option defined in 23 this document allows all response types to contain extended error 24 information. Extended DNS Error information does not change the 25 processing of RCODEs. 27 Status of This Memo 29 This Internet-Draft is submitted in full conformance with the 30 provisions of BCP 78 and BCP 79. 32 Internet-Drafts are working documents of the Internet Engineering 33 Task Force (IETF). Note that other groups may also distribute 34 working documents as Internet-Drafts. The list of current Internet- 35 Drafts is at https://datatracker.ietf.org/drafts/current/. 37 Internet-Drafts are draft documents valid for a maximum of six months 38 and may be updated, replaced, or obsoleted by other documents at any 39 time. It is inappropriate to use Internet-Drafts as reference 40 material or to cite them other than as "work in progress." 42 This Internet-Draft will expire on June 20, 2020. 44 Copyright Notice 46 Copyright (c) 2019 IETF Trust and the persons identified as the 47 document authors. All rights reserved. 49 This document is subject to BCP 78 and the IETF Trust's Legal 50 Provisions Relating to IETF Documents 51 (https://trustee.ietf.org/license-info) in effect on the date of 52 publication of this document. Please review these documents 53 carefully, as they describe your rights and restrictions with respect 54 to this document. Code Components extracted from this document must 55 include Simplified BSD License text as described in Section 4.e of 56 the Trust Legal Provisions and are provided without warranty as 57 described in the Simplified BSD License. 59 Table of Contents 61 1. Introduction and background . . . . . . . . . . . . . . . . . 3 62 1.1. Requirements notation . . . . . . . . . . . . . . . . . . 4 63 2. Extended DNS Error EDNS0 option format . . . . . . . . . . . 4 64 3. Extended DNS Error Processing . . . . . . . . . . . . . . . . 5 65 4. Defined Extended DNS Errors . . . . . . . . . . . . . . . . . 5 66 4.1. Extended DNS Error Code 0 - Other . . . . . . . . . . . . 5 67 4.2. Extended DNS Error Code 1 - 68 Unsupported DNSKEY Algorithm . . . . . . . . . . . . . . 6 69 4.3. Extended DNS Error Code 2 - Unsupported DS 70 Digest Type . . . . . . . . . . . . . . . . . . . . . . . 6 71 4.4. Extended DNS Error Code 3 - Stale Answer . . . . . . . . 6 72 4.5. Extended DNS Error Code 4 - Forged Answer . . . . . . . . 6 73 4.6. Extended DNS Error Code 5 - DNSSEC Indeterminate . . . . 6 74 4.7. Extended DNS Error Code 6 - DNSSEC Bogus . . . . . . . . 6 75 4.8. Extended DNS Error Code 7 - Signature Expired . . . . . . 6 76 4.9. Extended DNS Error Code 8 - Signature Not Yet Valid . . . 6 77 4.10. Extended DNS Error Code 9 - DNSKEY Missing . . . . . . . 7 78 4.11. Extended DNS Error Code 10 - RRSIGs Missing . . . . . . . 7 79 4.12. Extended DNS Error Code 11 - No Zone Key Bit Set . . . . 7 80 4.13. Extended DNS Error Code 12 - NSEC Missing . . . . . . . . 7 81 4.14. Extended DNS Error Code 13 - Cached Error . . . . . . . . 7 82 4.15. Extended DNS Error Code 14 - Not Ready . . . . . . . . . 7 83 4.16. Extended DNS Error Code 15 - Blocked . . . . . . . . . . 7 84 4.17. Extended DNS Error Code 16 - Censored . . . . . . . . . . 7 85 4.18. Extended DNS Error Code 17 - Filtered . . . . . . . . . . 7 86 4.19. Extended DNS Error Code 18 - Prohibited . . . . . . . . . 8 87 4.20. Extended DNS Error Code 19 - Stale NXDOMAIN Answer . . . 8 88 4.21. Extended DNS Error Code 20 - Not Authoritative . . . . . 8 89 4.22. Extended DNS Error Code 21 - Not Supported . . . . . . . 8 90 4.23. Extended DNS Error Code 22 - No Reachable Authority . . . 8 91 4.24. Extended DNS Error Code 23 - Network Error . . . . . . . 8 92 4.25. Extended DNS Error Code 24 - Invalid Data . . . . . . . . 8 93 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9 94 5.1. A New Extended DNS Error Code EDNS Option . . . . . . . . 9 95 5.2. New Registry Table for Extended DNS Error Codes . . . . . 9 96 6. Security Considerations . . . . . . . . . . . . . . . . . . . 11 97 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 12 98 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 12 99 8.1. Normative References . . . . . . . . . . . . . . . . . . 12 100 8.2. Informative References . . . . . . . . . . . . . . . . . 13 101 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 13 103 1. Introduction and background 105 There are many reasons that a DNS query may fail, some of them 106 transient, some permanent; some can be resolved by querying another 107 server, some are likely best handled by stopping resolution. 108 Unfortunately, the error signals that a DNS server can return are 109 very limited, and are not very expressive. This means that 110 applications and resolvers often have to "guess" at what the issue is 111 - e.g. was the answer marked REFUSED because of a lame delegation, or 112 because the nameserver is still starting up and loading zones? Is a 113 SERVFAIL a DNSSEC validation issue, or is the nameserver experiencing 114 some other failure? What error messages should be presented to the 115 user or logged under these conditions? 117 A good example of issues that would benefit by additional error 118 information are errors caused by DNSSEC validation issues. When a 119 stub resolver queries a name which is DNSSEC bogus (using a 120 validating resolver), the stub resolver receives only a SERVFAIL in 121 response. Unfortunately, the SERVFAIL Response Code (RCODE) is used 122 to signal many sorts of DNS errors, and so the stub resolvers only 123 option is to ask the next configured DNS resolver. The result of 124 trying the next resolver is one of two outcomes: either the next 125 resolver also validates, and a SERVFAIL is returned again or the next 126 resolver is not a validating resolver, and the user is returned a 127 potentially harmful result. With an Extended DNS Error (EDE) option 128 enclosed in the response message, the resolver is able to return a 129 more descriptive reason as to why any failures happened, or add 130 additional context to a message containing a NOERROR RCODE. 132 This document specifies a mechanism to extend DNS errors to provide 133 additional information about the cause of an error. These extended 134 DNS error codes described in this document and can be used by any 135 system that sends DNS queries and receives a response containing an 136 EDE option. Different codes are useful in different circumstances, 137 and thus different systems (stub resolvers, recursive resolvers, and 138 authoritative resolvers) might receive and use them. 140 This document does not allow or prohibit any particular extended 141 error codes and information to be matched with any particular RCODEs. 142 Some combinations of extended error codes and RCODEs may seem 143 nonsensical (such as resolver-specific extended error codes in 144 responses from authoritative servers), so systems interpreting the 145 extended error codes MUST NOT assume that a combination will make 146 sense. Receivers MUST be able to accept EDE codes and EXTRA-TEXT in 147 all messages, including those with a NOERROR RCODE. Applications 148 MUST continue to follow requirements from applicable specs on how to 149 process RCODEs no matter what EDE values is also received. Senders 150 MAY include more than one EDE option and receivers MUST be able to 151 accept (but not necessarily process or act on) multiple EDE options 152 in a DNS message. 154 1.1. Requirements notation 156 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 157 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 158 document are to be interpreted as described in [RFC2119]. 160 2. Extended DNS Error EDNS0 option format 162 This draft uses an EDNS0 ([RFC6891]) option to include Extended DNS 163 Error (EDE) information in DNS messages. The option is structured as 164 follows: 166 1 1 1 1 1 1 167 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 168 +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+ 169 0: | OPTION-CODE | 170 +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+ 171 2: | OPTION-LENGTH | 172 +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+ 173 4: | INFO-CODE | 174 +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+ 175 6: / EXTRA-TEXT ... / 176 +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+ 178 Field definition details: 180 o OPTION-CODE, 2-octets/16-bits (defined in [RFC6891]]), for EDE is 181 TBD. [RFC Editor: change TBD to the proper code once assigned by 182 IANA.] 183 o OPTION-LENGTH, 2-octets/16-bits ((defined in [RFC6891]]) contains 184 the length of the payload (everything after OPTION-LENGTH) in 185 octets and should be 2 plus the length of the EXTRA-TEXT field 186 (which may be a zero-length string). 187 o INFO-CODE, 16-bits, which is the principal contribution of this 188 document. This 16-bit value, encoded in network (MSB) byte order, 189 provides the additional context for the RESPONSE-CODE of the DNS 190 message. The INFO-CODE serves as an index into the "Extended DNS 191 Errors" registry Section 5.1. 193 o EXTRA-TEXT, a variable length, UTF-8 encoded, text field that may 194 hold additional textual information. Note: EXTRA-TEXT may be zero 195 octets in length, indicating there is no EXTRA-TEXT included. 196 Care should be taken not to leak private information that an 197 observer would not otherwise have access to, such as account 198 numbers. 200 The Extended DNS Error (EDE) option can be included in any response 201 (SERVFAIL, NXDOMAIN, REFUSED, and even NOERROR, etc) to a query that 202 includes OPT Pseudo-RR [RFC6891]. This document includes a set of 203 initial codepoints (and requests to the IANA to add them to the 204 registry), but is extensible via the IANA registry to allow 205 additional error and information codes to be defined in the future. 207 3. Extended DNS Error Processing 209 When the response grows beyond the requestor's UDP payload size 210 [RFC6891], servers SHOULD truncate messages by dropping EDE options 211 before dropping other data from packets. Implementations SHOULD set 212 the truncation bit when dropping EDE options. 214 When a resolver or forwarder receives an EDE option, whether or not 215 (and how) to pass along EDE information on to their original client 216 is implementation dependent. Implementations MAY choose to not 217 forward information, or they MAY choose to create a new EDE option(s) 218 that conveys the information encoded in the received EDE. When doing 219 so, care should be taken to ensure any information is properly 220 attributed since an EDNS0 option received by the original client will 221 be perceived only to have come from the resolver or forwarder sending 222 it. 224 4. Defined Extended DNS Errors 226 This document defines some initial EDE codes. The mechanism is 227 intended to be extensible, and additional code-points can be 228 registered in the "Extended DNS Errors" registry Section 5.1. The 229 INFO-CODE from the EDE EDNS option is used to serve as an index into 230 the "Extended DNS Error" IANA registry, the initial values for which 231 are defined in the following sub-sections. 233 4.1. Extended DNS Error Code 0 - Other 235 The error in question falls into a category that does not match known 236 extended error codes. Implementations SHOULD include a EXTRA-TEXT 237 value to augment this error code with additional information. 239 4.2. Extended DNS Error Code 1 - Unsupported DNSKEY Algorithm 241 The resolver attempted to perform DNSSEC validation, but a DNSKEY 242 RRSET contained only unsupported DNSSEC algorithms. 244 4.3. Extended DNS Error Code 2 - Unsupported DS Digest Type 246 The resolver attempted to perform DNSSEC validation, but a DS RRSET 247 contained only unsupported Digest Types. 249 4.4. Extended DNS Error Code 3 - Stale Answer 251 The resolver was unable to resolve answer within its time limits and 252 decided to answer with previously cached data instead of answering 253 with an error. This is typically caused by problems communicating 254 with an authoritative serever, possibly as result of a DoS attack 255 against another network. 257 4.5. Extended DNS Error Code 4 - Forged Answer 259 For policy reasons (legal obligation, or malware filtering, for 260 instance), an answer was forged. Note that this should be used when 261 an answer is still provided, not when failure codes are returned 262 instead. See Blocked(15), Censored (16), and Filtered (17) for use 263 when returning other response codes. 265 4.6. Extended DNS Error Code 5 - DNSSEC Indeterminate 267 The resolver attempted to perform DNSSEC validation, but validation 268 ended in the Indeterminate state [RFC4035]. 270 4.7. Extended DNS Error Code 6 - DNSSEC Bogus 272 The resolver attempted to perform DNSSEC validation, but validation 273 ended in the Bogus state. 275 4.8. Extended DNS Error Code 7 - Signature Expired 277 The resolver attempted to perform DNSSEC validation, but no 278 signatures are presently valid and some (often all) are expired. 280 4.9. Extended DNS Error Code 8 - Signature Not Yet Valid 282 The resolver attempted to perform DNSSEC validation, but but no 283 signatures are presently valid and at least some are not yet valid. 285 4.10. Extended DNS Error Code 9 - DNSKEY Missing 287 A DS record existed at a parent, but no supported matching DNSKEY 288 record could be found for the child. 290 4.11. Extended DNS Error Code 10 - RRSIGs Missing 292 The resolver attempted to perform DNSSEC validation, but no RRSIGs 293 could be found for at least one RRset where RRSIGs were expected. 295 4.12. Extended DNS Error Code 11 - No Zone Key Bit Set 297 The resolver attempted to perform DNSSEC validation, but no Zone Key 298 Bit was set in a DNSKEY. 300 4.13. Extended DNS Error Code 12 - NSEC Missing 302 The resolver attempted to perform DNSSEC validation, but the 303 requested data was missing and a covering NSEC or NSEC3 was not 304 provided. 306 4.14. Extended DNS Error Code 13 - Cached Error 308 The resolver is returning the SERVFAIL RCODE from its cache. 310 4.15. Extended DNS Error Code 14 - Not Ready 312 The server is unable to answer the query as it is not fully 313 functional (yet). 315 4.16. Extended DNS Error Code 15 - Blocked 317 The server is unable to respond to the request because the domain is 318 blacklisted due to an internal security policy imposed by the 319 operator of the server being directly talked to. 321 4.17. Extended DNS Error Code 16 - Censored 323 The server is unable to respond to the request because the domain is 324 blacklisted by a security policy imposed upon the server being talked 325 to by an external requirement. Note that how the imposed policy is 326 applied is irrelevant (in-band DNS filtering, court order, etc). 328 4.18. Extended DNS Error Code 17 - Filtered 330 The server is unable to respond to the request because the domain is 331 blacklisted as requested by the client. Functionally, this amounts 332 to "you requested that we filter domains like this one." 334 4.19. Extended DNS Error Code 18 - Prohibited 336 An authoritative or recursive resolver that receives a query from an 337 "unauthorized" client can annotate its REFUSED message with this 338 code. Examples of "unauthorized" clients are recursive queries from 339 IP addresses outside the network, blacklisted IP addresses, local 340 policy, etc. 342 4.20. Extended DNS Error Code 19 - Stale NXDOMAIN Answer 344 The resolver was unable to resolve an answer within its configured 345 time limits and decided to answer with a previously cached NXDOMAIN 346 answer instead of answering with an error. This is may be caused, 347 for example, by problems communicating with an authoritative server, 348 possibly as result of a DoS attack against another network. 350 4.21. Extended DNS Error Code 20 - Not Authoritative 352 An authoritative server that receives a query (with the RD bit clear, 353 or when not configured for recursion) for a domain for which it is 354 not authoritative SHOULD include this EDE code in the REFUSED 355 response. A resolver that receives a query (with the RD bit clear) 356 SHOULD include this EDE code in the REFUSED response. 358 4.22. Extended DNS Error Code 21 - Not Supported 360 The requested operation or query is not supported as its use has been 361 deprecated. 363 4.23. Extended DNS Error Code 22 - No Reachable Authority 365 The resolver could not reach any of the authoritative name servers 366 (or they refused to reply). 368 4.24. Extended DNS Error Code 23 - Network Error 370 An unrecoverable error occurred while communicating with another 371 server. 373 4.25. Extended DNS Error Code 24 - Invalid Data 375 An authoritative server that cannot answer with data for a zone it is 376 otherwise configured to support. This may occur because its most 377 recent zone is too old, or has expired, for example. 379 5. IANA Considerations 381 5.1. A New Extended DNS Error Code EDNS Option 383 This document defines a new EDNS(0) option, entitled "Extended DNS 384 Error", assigned a value of TBD1 from the "DNS EDNS0 Option Codes 385 (OPT)" registry [to be removed upon publication: 386 [http://www.iana.org/assignments/dns-parameters/dns- 387 parameters.xhtml#dns-parameters-11] 389 Value Name Status Reference 390 ----- ---------------- ------ ------------------ 391 TBD Extended DNS Error TBD [ This document ] 393 5.2. New Registry Table for Extended DNS Error Codes 395 This document defines a new IANA registry table, where the index 396 value is the INFO-CODE from the "Extended DNS Error" EDNS option 397 defined in this document. The IANA is requested to create and 398 maintain this "Extended DNS Error" codes registry. The code-point 399 space for the INFO-CODE index is to be broken into 2 ranges: 401 o 0 - 49151: First come, first served. 402 o 49152 - 65280: Private use. 404 A starting set of entries, based on the contents of this document, is 405 as follows: 407 INFO-CODE: 0 408 Purpose: Other Error 409 Reference: Section 4.1 411 INFO-CODE: 1 412 Purpose: Unsupported DNSKEY Algorithm 413 Reference: Section 4.2 415 INFO-CODE: 2 416 Purpose: Unsupported DS Digest Type 417 Reference: Section 4.3 419 INFO-CODE: 3 420 Purpose: Stale Answer 421 Reference: Section 4.4, [I-D.ietf-dnsop-serve-stale] 423 INFO-CODE: 4 424 Purpose: Forged Answer 425 Reference: Section 4.5 426 INFO-CODE: 5 427 Purpose: DNSSEC Indeterminate 428 Reference: Section 4.6 430 INFO-CODE: 6 431 Purpose: DNSSEC Bogus 432 Reference: Section 4.7 434 INFO-CODE: 7 435 Purpose: Signature Expired 436 Reference: Section 4.8 438 INFO-CODE: 8 439 Purpose: Signature Not Yet Valid 440 Reference: Section 4.9 442 INFO-CODE: 9 443 Purpose: DNSKEY Missing 444 Reference: Section 4.10 446 INFO-CODE: 10 447 Purpose: RRSIGs Missing 448 Reference: Section 4.11 450 INFO-CODE: 11 451 Purpose: No Zone Key Bit Set 452 Reference: Section 4.12 454 INFO-CODE: 12 455 Purpose: NSEC Missing 456 Reference: Section 4.13 458 INFO-CODE: 13 459 Purpose: Cached Error 460 Reference: Section 4.14 462 INFO-CODE: 14 463 Purpose: Not Ready. 464 Reference: Section 4.15 466 INFO-CODE: 15 467 Purpose: Blocked 468 Reference: Section 4.16 470 INFO-CODE: 16 471 Purpose: Censored 472 Reference: Section 4.17 473 INFO-CODE: 17 474 Purpose: Filtered 475 Reference: Section 4.18 477 INFO-CODE: 18 478 Purpose: Prohibited 479 Reference: Section 4.19 481 INFO-CODE: 19 482 Purpose: Stale NXDomain Answer 483 Reference: Section 4.20 485 INFO-CODE: 20 486 Purpose: Not Authoritative 487 Reference: Section 4.21 489 INFO-CODE: 21 490 Purpose: Not Supported 491 Reference: Section 4.22 493 INFO-CODE: 22 494 Purpose: No Reachable Authority 495 Reference: Section 4.23 497 INFO-CODE: 23 498 Purpose: Network Error 499 Reference: Section 4.24 501 INFO-CODE: 24 502 Purpose: Invalid Data 503 Reference: Section 4.25 505 6. Security Considerations 507 Though DNSSEC continues to be deployed, unfortunately a significant 508 number of clients (~11% according to [GeoffValidation]) that receive 509 a SERVFAIL from a validating resolver because of a DNSSEC validaion 510 issue will simply ask the next (potentially non-validating) resolver 511 in their list, and thus don't get any of the protections which DNSSEC 512 should provide. 514 This information is unauthenticated information, and an attacker (e.g 515 a MITM or malicious recursive server) could insert an extended error 516 response into already untrusted data -- ideally clients and resolvers 517 would not trust any unauthenticated information, but until we live in 518 an era where all DNS answers are authenticated via DNSSEC or other 519 mechanisms [RFC2845] [RFC8094], there are some tradeoffs. As an 520 example, an attacker who is able to insert the DNSSEC Bogus Extended 521 Error into a packet could instead simply reply with a fictitious 522 address (A or AAAA) record. Note that DNS Response Codes also 523 contain no authentication and can be just as easily manipulated. 525 7. Acknowledgements 527 The authors wish to thank Joe Abley, Mark Andrews, Tim April, 528 Vittorio Bertola, Stephane Bortzmeyer, Vladimir Cunat, Ralph Dolmans, 529 Peter DeVries, Peter van Dijk, Mats Dufberg, Donald Eastlake, Bob 530 Harold, Paul Hoffman, Geoff Huston, Shane Kerr, Edward Lewis, Carlos 531 M. Martinez, George Michelson, Eric Orth, Michael Sheldon, Puneet 532 Sood, Petr Spacek, Ondrej Sury, John Todd, Loganaden Velvindron, and 533 Paul Vixie. They also vaguely remember discussing this with a number 534 of people over the years, but have forgotten who all they were -- if 535 you were one of them, and are not listed, please let us know and 536 we'll acknowledge you. 538 One author also wants to thank the band "Infected Mushroom" for 539 providing a good background soundtrack (and to see if he can get away 540 with this in an RFC!) Another author would like to thank the band 541 "Mushroom Infectors". This was funny at the time we wrote it, but we 542 cannot remember why... 544 8. References 546 8.1. Normative References 548 [I-D.ietf-dnsop-serve-stale] 549 Lawrence, D., Kumari, W., and P. Sood, "Serving Stale Data 550 to Improve DNS Resiliency", draft-ietf-dnsop-serve- 551 stale-10 (work in progress), December 2019. 553 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 554 Requirement Levels", BCP 14, RFC 2119, 555 DOI 10.17487/RFC2119, March 1997, 556 . 558 [RFC4035] Arends, R., Austein, R., Larson, M., Massey, D., and S. 559 Rose, "Protocol Modifications for the DNS Security 560 Extensions", RFC 4035, DOI 10.17487/RFC4035, March 2005, 561 . 563 [RFC6891] Damas, J., Graff, M., and P. Vixie, "Extension Mechanisms 564 for DNS (EDNS(0))", STD 75, RFC 6891, 565 DOI 10.17487/RFC6891, April 2013, 566 . 568 8.2. Informative References 570 [GeoffValidation] 571 APNIC, G. H., "A quick review of DNSSEC Validation in 572 today's Internet", June 2016, . 575 [RFC2845] Vixie, P., Gudmundsson, O., Eastlake 3rd, D., and B. 576 Wellington, "Secret Key Transaction Authentication for DNS 577 (TSIG)", RFC 2845, DOI 10.17487/RFC2845, May 2000, 578 . 580 [RFC8094] Reddy, T., Wing, D., and P. Patil, "DNS over Datagram 581 Transport Layer Security (DTLS)", RFC 8094, 582 DOI 10.17487/RFC8094, February 2017, 583 . 585 Authors' Addresses 587 Warren Kumari 588 Google 589 1600 Amphitheatre Parkway 590 Mountain View, CA 94043 591 US 593 Email: warren@kumari.net 595 Evan Hunt 596 ISC 597 950 Charter St 598 Redwood City, CA 94063 599 US 601 Email: each@isc.org 603 Roy Arends 604 ICANN 606 Email: roy.arends@icann.org 607 Wes Hardaker 608 USC/ISI 609 P.O. Box 382 610 Davis, CA 95617 611 US 613 Email: ietf@hardakers.net 615 David C Lawrence 616 Oracle + Dyn 617 150 Dow St 618 Manchester, NH 03101 619 US 621 Email: tale@dd.org