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Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year -- The document date (3 December 2021) is 162 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: 2 errors (**), 0 flaws (~~), 1 warning (==), 1 comment (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Network Working Group E. Chen 3 Internet-Draft Palo Alto Networks 4 Intended status: Standards Track N. Shen 5 Expires: 6 June 2022 Zededa 6 R. Raszuk 7 NTT Network Innovations 8 R. Rahman 9 3 December 2021 11 Unsolicited BFD for Sessionless Applications 12 draft-ietf-bfd-unsolicited-09 14 Abstract 16 For operational simplification of "sessionless" applications using 17 BFD, in this document we present procedures for "unsolicited BFD" 18 that allow a BFD session to be initiated by only one side, and be 19 established without explicit per-session configuration or 20 registration by the other side (subject to certain per-interface or 21 per-router policies). 23 We also introduce a new YANG module to configure and manage 24 "unsolicited BFD". The YANG module in this document conforms to the 25 Network Management Datastore Architecture (NMDA) [RFC8342]. 27 Requirements Language 29 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 30 "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and 31 "OPTIONAL" in this document are to be interpreted as described in BCP 32 14 [RFC2119] [RFC8174] when, and only when, they appear in all 33 capitals, as shown here. 35 Status of This Memo 37 This Internet-Draft is submitted in full conformance with the 38 provisions of BCP 78 and BCP 79. 40 Internet-Drafts are working documents of the Internet Engineering 41 Task Force (IETF). Note that other groups may also distribute 42 working documents as Internet-Drafts. The list of current Internet- 43 Drafts is at https://datatracker.ietf.org/drafts/current/. 45 Internet-Drafts are draft documents valid for a maximum of six months 46 and may be updated, replaced, or obsoleted by other documents at any 47 time. It is inappropriate to use Internet-Drafts as reference 48 material or to cite them other than as "work in progress." 49 This Internet-Draft will expire on 6 June 2022. 51 Copyright Notice 53 Copyright (c) 2021 IETF Trust and the persons identified as the 54 document authors. All rights reserved. 56 This document is subject to BCP 78 and the IETF Trust's Legal 57 Provisions Relating to IETF Documents (https://trustee.ietf.org/ 58 license-info) in effect on the date of publication of this document. 59 Please review these documents carefully, as they describe your rights 60 and restrictions with respect to this document. Code Components 61 extracted from this document must include Revised BSD License text as 62 described in Section 4.e of the Trust Legal Provisions and are 63 provided without warranty as described in the Revised BSD License. 65 Table of Contents 67 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 68 2. Procedures for Unsolicited BFD . . . . . . . . . . . . . . . 3 69 3. State Variables . . . . . . . . . . . . . . . . . . . . . . . 4 70 4. YANG Data Model . . . . . . . . . . . . . . . . . . . . . . . 5 71 4.1. Unsolicited BFD Hierarchy . . . . . . . . . . . . . . . . 5 72 4.2. Unsolicited BFD Module . . . . . . . . . . . . . . . . . 6 73 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10 74 6. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 10 75 7. Security Considerations . . . . . . . . . . . . . . . . . . . 10 76 7.1. BFD Protocol Security Considerations . . . . . . . . . . 11 77 7.2. YANG Module Security Considerations . . . . . . . . . . . 11 78 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 12 79 8.1. Normative References . . . . . . . . . . . . . . . . . . 12 80 8.2. Informative References . . . . . . . . . . . . . . . . . 14 81 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 14 83 1. Introduction 85 The current implementation and deployment practice for BFD ([RFC5880] 86 and [RFC5881]) usually requires BFD sessions be explicitly configured 87 or registered on both sides. This requirement is not an issue when 88 an application like BGP [RFC4271] has the concept of a "session" that 89 involves both sides for its establishment. However, this requirement 90 can be operationally challenging when the prerequisite "session" does 91 not naturally exist between two endpoints in an application. 92 Simultaneous configuration and coordination may be required on both 93 sides for BFD to take effect. For example: 95 * When BFD is used to keep track of the "liveness" of the nexthop of 96 static routes. Although only one side may need the BFD 97 functionality, currently both sides need to be involved in 98 specific configuration and coordination and in some cases static 99 routes are created unnecessarily just for BFD. 100 * When BFD is used to keep track of the "liveness" of the third-pary 101 nexthop of BGP routes received from the Route Server [RFC7947] at 102 an Internet Exchange Point (IXP). As the third-party nexthop is 103 different from the peering address of the Route Server, for BFD to 104 work, currently two routers peering with the Route Server need to 105 have routes and nexthops from each other (although indirectly via 106 the Router Server), and the nexthop of each router must be present 107 at the same time. These issues are also discussed in 108 [I-D.ietf-idr-rs-bfd]. 110 Clearly it is beneficial and desirable to reduce or eliminate 111 unnecessary configurations and coordination in these "sessionless" 112 applications using BFD. 114 In this document we present procedures for "unsolicited BFD" that 115 allow a BFD session to be initiated by only one side, and be 116 established without explicit per-session configuration or 117 registration by the other side (subject to certain per-interface or 118 per-router policies). 120 With "unsolicited BFD" there is potential risk for excessive resource 121 usage by BFD from "unexpected" remote systems. To mitigate such 122 risks, several mechanisms are recommended in the Security 123 Considerations section. 125 Compared to the "Seamless BFD" [RFC7880], this proposal involves only 126 minor procedural enhancements to the widely deployed BFD itself. 127 Thus we believe that this proposal is inherently simpler in the 128 protocol itself and deployment. As an example, it does not require 129 the exchange of BFD discriminators over an out-of-band channel before 130 the BFD session bring-up. 132 When BGP Add-Path [RFC7911] is deployed at an IXP using the Route 133 Server, multiple BGP paths (when exist) can be made available to the 134 clients of the Router Server as described in [RFC7947]. The 135 "unsolicited BFD" can be used in BGP route selection by these clients 136 to eliminate paths with "inaccessible nexthops". 138 2. Procedures for Unsolicited BFD 140 With "unsolicited BFD", one side takes the "Active role" and the 141 other side takes only the "Passive role" as described in [RFC5880]. 143 On the passive side, the "unsolicited BFD" SHOULD be explicitly 144 configured on an interface or globally (apply to all interfaces). 145 The BFD parameters can be either per-interface or per-router based. 146 It MAY also choose to use the parameters that the active side uses in 147 its BFD Control packets. The "My Discriminator", however, MUST be 148 chosen to allow multiple unsolicited BFD sessions. 150 The active side starts sending the BFD Control packets as specified 151 in [RFC5880]. The passive side does not send BFD Control packets. 153 When the passive side receives a BFD Control packet from the active 154 side with 0 as "Your Discriminator" and does not find an existing BFD 155 session, the passive side MAY create a matching BFD session toward 156 the active side, if permitted by local configuration. 158 It would then start sending the BFD Control packets and perform 159 necessary procedure for bringing up, maintaining and tearing down the 160 BFD session. If the BFD session fails to get established within 161 certain specified time, or if an established BFD session goes down, 162 the passive side would stop sending BFD Control packets and MAY 163 delete the BFD session created until the BFD Control packets is 164 initiated by the active side again. 166 When an Unsolicited BFD session goes down, an implementation MAY 167 retain the session state for a period of time, which may be 168 configurable. Retaining this state can be useful for operational 169 purposes. 171 The "Passive role" may change to the "Active role" when a local 172 client registers for the same BFD session, and from the "Active role" 173 to the "Passive role" when there is no longer any locally registered 174 client for the BFD session. 176 3. State Variables 178 This document defines a new state variable called Unsolicited Role. 180 bfd.UnsolicitedRole 182 The operational mode of BFD interface when configured for unsolicited 183 behaviour. Options can be either PASSIVE, ACTIVE or NULL (NULL - not 184 initialized) for unsolicited BFD sessions. Default (not configured 185 for unsolicited behaviour) MUST be set to NULL if present on the 186 interface. 188 4. YANG Data Model 190 This section extends the YANG data model for BFD [RFC9127] to cover 191 unsolicited BFD. We import [RFC8349] since the "bfd" container in 192 [RFC9127] is under "control-plane-protocol". 194 4.1. Unsolicited BFD Hierarchy 196 Configuration for unsolicited BFD parameters for IP single-hop 197 sessions can be done at 2 levels: 199 * Globally, i.e. for all interfaces. This requires support for the 200 "unsolicited-params-global" feature. 201 * For specific interfaces. This requires support for the 202 "unsolicited-params-per-interface" feature. 204 For operational data, a new "unsolicited" container has been added 205 for BFD IP single-hop sessions. 207 The tree diagram below uses the graphical representation of data 208 models, as defined in [RFC8340]. 210 module: ietf-bfd-unsolicited 212 augment /rt:routing/rt:control-plane-protocols 213 /rt:control-plane-protocol/bfd:bfd/bfd-ip-sh:ip-sh: 214 +--rw unsolicited {bfd-unsol:unsolicited-params-global}? 215 +--rw enabled? boolean 216 +--rw local-multiplier? multiplier 217 +--rw (interval-config-type)? 218 +--:(tx-rx-intervals) 219 | +--rw desired-min-tx-interval? uint32 220 | +--rw required-min-rx-interval? uint32 221 +--:(single-interval) {single-minimum-interval}? 222 +--rw min-interval? uint32 223 augment /rt:routing/rt:control-plane-protocols 224 /rt:control-plane-protocol/bfd:bfd/bfd-ip-sh:ip-sh 225 /bfd-ip-sh:interfaces: 226 +--rw unsolicited {bfd-unsol:unsolicited-params-per-interface}? 227 +--rw enabled? boolean 228 +--rw local-multiplier? multiplier 229 +--rw (interval-config-type)? 230 +--:(tx-rx-intervals) 231 | +--rw desired-min-tx-interval? uint32 232 | +--rw required-min-rx-interval? uint32 233 +--:(single-interval) {single-minimum-interval}? 234 +--rw min-interval? uint32 235 augment /rt:routing/rt:control-plane-protocols 236 /rt:control-plane-protocol/bfd:bfd/bfd-ip-sh:ip-sh 237 /bfd-ip-sh:sessions/bfd-ip-sh:session: 238 +--ro unsolicited 239 +--ro role? bfd-unsol:unsolicited-role 241 4.2. Unsolicited BFD Module 243 file "ietf-bfd-unsolicited@2021-11-23.yang" 244 module ietf-bfd-unsolicited { 246 yang-version 1.1; 248 namespace "urn:ietf:params:xml:ns:yang:ietf-bfd-unsolicited"; 250 prefix "bfd-unsol"; 252 // RFC Ed.: replace occurences of YYYY with actual RFC numbers 253 // and remove this note 255 import ietf-bfd-types { 256 prefix "bfd-types"; 257 reference 258 "RFC 9127: YANG Data Model for Bidirectional Forwarding Detection 259 (BFD)"; 260 } 262 import ietf-bfd { 263 prefix "bfd"; 264 reference 265 "RFC 9127: YANG Data Model for Bidirectional Forwarding Detection 266 (BFD)"; 267 } 269 import ietf-bfd-ip-sh { 270 prefix "bfd-ip-sh"; 271 reference 272 "RFC 9127: YANG Data Model for Bidirectional Forwarding Detection 273 (BFD)"; 274 } 276 import ietf-routing { 277 prefix "rt"; 278 reference 279 "RFC 8349: A YANG Data Model for Routing Management 280 (NMDA version)"; 281 } 283 organization "IETF BFD Working Group"; 285 contact 286 "WG Web: 287 WG List: 289 Editors: Enke Chen (enchen@paloaltonetworks.com), 290 Naiming Shen (naiming@zededa.com), 291 Robert Raszuk (robert@raszuk.net), 292 Reshad Rahman (reshad@yahoo.com)"; 294 description 295 "This module contains the YANG definition for BFD unsolicited 296 as per RFC YYYY. 298 Copyright (c) 2021 IETF Trust and the persons 299 identified as authors of the code. All rights reserved. 301 Redistribution and use in source and binary forms, with or 302 without modification, is permitted pursuant to, and subject 303 to the license terms contained in, the Simplified BSD License 304 set forth in Section 4.c of the IETF Trust's Legal Provisions 305 Relating to IETF Documents 306 (http://trustee.ietf.org/license-info). 308 This version of this YANG module is part of RFC YYYY; see 309 the RFC itself for full legal notices."; 311 reference "RFC YYYY"; 313 revision 2021-11-23 { 314 description 315 "Initial revision."; 316 reference 317 "RFC YYYY: Unsolicited BFD for Sessionless Applications."; 318 } 320 /* 321 * Feature definitions 322 */ 323 feature unsolicited-params-global { 324 description 325 "This feature indicates that the server supports global 326 parameters for unsolicited sessions."; 327 reference 328 "RFC YYYY: Unsolicited BFD for Sessionless Applications."; 329 } 331 feature unsolicited-params-per-interface { 332 description 333 "This feature indicates that the server supports per-interface 334 parameters for unsolicited sessions."; 335 reference 336 "RFC YYYY: Unsolicited BFD for Sessionless Applications."; 337 } 339 /* 340 * Type Definitions 341 */ 342 typedef unsolicited-role { 343 type enumeration { 344 enum unsolicited-active { 345 description "Active role"; 346 } 347 enum unsolicited-passive { 348 description "Passive role"; 349 } 350 } 351 description "Unsolicited role"; 353 } 355 /* 356 * Augments 357 */ 358 augment "/rt:routing/rt:control-plane-protocols/" 359 + "rt:control-plane-protocol/bfd:bfd/bfd-ip-sh:ip-sh" { 360 if-feature bfd-unsol:unsolicited-params-global; 361 description 362 "Augmentation for BFD unsolicited parameters"; 363 container unsolicited { 364 description 365 "BFD unsolicited top level container"; 366 leaf enabled { 367 type boolean; 368 default false; 369 description 370 "BFD unsolicited enabled globally for IP single-hop."; 371 } 372 uses bfd-types:base-cfg-parms; 373 } 374 } 376 augment "/rt:routing/rt:control-plane-protocols/" 377 + "rt:control-plane-protocol/bfd:bfd/bfd-ip-sh:ip-sh/" 378 + "bfd-ip-sh:interfaces" { 379 if-feature bfd-unsol:unsolicited-params-per-interface; 380 description 381 "Augmentation for BFD unsolicited on IP single-hop interface"; 382 container unsolicited { 383 description 384 "BFD IP single-hop interface unsolicited top level 385 container"; 386 leaf enabled { 387 type boolean; 388 default false; 389 description 390 "BFD unsolicited enabled on this interface."; 391 } 392 uses bfd-types:base-cfg-parms; 393 } 394 } 396 augment "/rt:routing/rt:control-plane-protocols/" 397 + "rt:control-plane-protocol/bfd:bfd/bfd-ip-sh:ip-sh/" 398 + "bfd-ip-sh:sessions/bfd-ip-sh:session" { 399 description 400 "Augmentation for BFD unsolicited on IP single-hop session"; 402 container unsolicited { 403 config false; 404 description 405 "BFD IP single-hop session unsolicited top level container"; 406 leaf role { 407 type bfd-unsol:unsolicited-role; 408 description "Role."; 409 } 410 } 411 } 412 } 413 415 5. IANA Considerations 417 This document registers the following namespace URI in the "IETF XML 418 Registry" [RFC3688]: 420 URI: urn:ietf:params:xml:ns:yang:ietf-bfd-unsolicited 422 Registrant Contact: The IESG. 424 XML: N/A; the requested URI is an XML namespace. 426 This document registers the following YANG module in the "YANG Module 427 Names" registry [RFC6020]: 429 Name: ietf-bfd-unsolicited 431 Namespace: urn:ietf:params:xml:ns:yang:ietf-bfd-unsolicited 433 Prefix: bfd-unsol 435 Reference: RFC YYYY 437 6. Acknowledgments 439 Authors would like to thank Acee Lindem, Greg Mirsky, Jeffrey Haas, 440 Raj Chetan and Tom Petch for their review and valuable input. 442 7. Security Considerations 443 7.1. BFD Protocol Security Considerations 445 The same security considerations and protection measures as those 446 described in [RFC5880] and [RFC5881] normatively apply to this 447 document. With "unsolicited BFD" there is potential risk for 448 excessive resource usage by BFD from "unexpected" remote systems. To 449 mitigate such risks, the following measures are mandatory: 451 * Limit the feature to specific interfaces, and to a single-hop BFD 452 with "TTL=255" [RFC5082]. For numbered interfaces, the source 453 address of an incoming BFD packet should belong to the subnet of 454 the interface on which the BFD packet is received. For unnumbered 455 interfaces the above check should be aligned with routing protocol 456 addresses running on such pair of interfaces. 457 * Apply "policy" to allow BFD packets only from certain subnets or 458 hosts. 459 * Deploy the feature only in certain "trustworthy" environment, 460 e.g., at an IXP, or between a provider and its customers. 461 * Adjust BFD parameters as needed for the particular deployment and 462 scale. 463 * Use BFD authentication. 465 7.2. YANG Module Security Considerations 467 The YANG module specified in this document defines a schema for data 468 that is designed to be accessed via network management protocols such 469 as NETCONF [RFC6241] or RESTCONF [RFC8040]. The lowest NETCONF layer 470 is the secure transport layer, and the mandatory-to-implement secure 471 transport is Secure Shell (SSH) [RFC6242]. The lowest RESTCONF layer 472 is HTTPS, and the mandatory-to-implement secure transport is TLS 473 [RFC8446]. 475 The NETCONF access control model [RFC8341] provides the means to 476 restrict access for particular NETCONF or RESTCONF users to a 477 preconfigured subset of all available NETCONF or RESTCONF protocol 478 operations and content. 480 There are a number of data nodes defined in this YANG module that are 481 writable/creatable/deletable (i.e., config true, which is the 482 default). These data nodes may be considered sensitive or vulnerable 483 in some network environments. Write operations (e.g., edit-config) 484 to these data nodes without proper protection can have a negative 485 effect on network operations. These are the subtrees and data nodes 486 and their sensitivity/vulnerability: 488 /routing/control-plane-protocols/control-plane-protocol/bfd/ip-sh 489 /unsolicited: 491 * data node "enabled" enables creation of unsolicited BFD IP single- 492 hop sessions globally, i.e. on all interfaces. See Section 7.1. 493 * data nodes local-multiplier, desired-min-tx-interval, required- 494 min-rx-interval and min-interval all impact the parameters of the 495 unsolicited BFD IP single-hop sessions. 497 /routing/control-plane-protocols/control-plane-protocol/bfd/ip-sh 498 /interfaces/interface/unsolicited: 500 * data node "enabled" enables creation of unsolicited BFD IP single- 501 hop sessions on a specific interface. See Section 7.1. 502 * data nodes local-multiplier, desired-min-tx-interval, required- 503 min-rx-interval and min-interval all impact the parameters of the 504 unsolicited BFD IP single-hop sessions on the interface. 506 Some of the readable data nodes in this YANG module may be considered 507 sensitive or vulnerable in some network environments. It is thus 508 important to control read access (e.g., via get, get-config, or 509 notification) to these data nodes. These are the subtrees and data 510 nodes and their sensitivity/vulnerability: 512 /routing/control-plane-protocols/control-plane-protocol/bfd/ip-sh 513 /sessions/session/unsolicited: access to this information discloses 514 the role of the local system in the creation of the unsolicited BFD 515 session. 517 8. References 519 8.1. Normative References 521 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 522 Requirement Levels", BCP 14, RFC 2119, 523 DOI 10.17487/RFC2119, March 1997, 524 . 526 [RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, 527 DOI 10.17487/RFC3688, January 2004, 528 . 530 [RFC5082] Gill, V., Heasley, J., Meyer, D., Savola, P., Ed., and C. 531 Pignataro, "The Generalized TTL Security Mechanism 532 (GTSM)", RFC 5082, DOI 10.17487/RFC5082, October 2007, 533 . 535 [RFC5880] Katz, D. and D. Ward, "Bidirectional Forwarding Detection 536 (BFD)", RFC 5880, DOI 10.17487/RFC5880, June 2010, 537 . 539 [RFC5881] Katz, D. and D. Ward, "Bidirectional Forwarding Detection 540 (BFD) for IPv4 and IPv6 (Single Hop)", RFC 5881, 541 DOI 10.17487/RFC5881, June 2010, 542 . 544 [RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for 545 the Network Configuration Protocol (NETCONF)", RFC 6020, 546 DOI 10.17487/RFC6020, October 2010, 547 . 549 [RFC6241] Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed., 550 and A. Bierman, Ed., "Network Configuration Protocol 551 (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011, 552 . 554 [RFC6242] Wasserman, M., "Using the NETCONF Protocol over Secure 555 Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011, 556 . 558 [RFC8040] Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF 559 Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017, 560 . 562 [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 563 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, 564 May 2017, . 566 [RFC8340] Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams", 567 BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018, 568 . 570 [RFC8341] Bierman, A. and M. Bjorklund, "Network Configuration 571 Access Control Model", STD 91, RFC 8341, 572 DOI 10.17487/RFC8341, March 2018, 573 . 575 [RFC8349] Lhotka, L., Lindem, A., and Y. Qu, "A YANG Data Model for 576 Routing Management (NMDA Version)", RFC 8349, 577 DOI 10.17487/RFC8349, March 2018, 578 . 580 [RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol 581 Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018, 582 . 584 [RFC9127] Rahman, R., Ed., Zheng, L., Ed., Jethanandani, M., Ed., 585 Pallagatti, S., and G. Mirsky, "YANG Data Model for 586 Bidirectional Forwarding Detection (BFD)", RFC 9127, 587 DOI 10.17487/RFC9127, October 2021, 588 . 590 8.2. Informative References 592 [I-D.ietf-idr-rs-bfd] 593 Bush, R., Haas, J., Scudder, J. G., Nipper, A., and C. 594 Dietzel, "Making Route Servers Aware of Data Link Failures 595 at IXPs", Work in Progress, Internet-Draft, draft-ietf- 596 idr-rs-bfd-09, 21 September 2020, 597 . 600 [RFC4271] Rekhter, Y., Ed., Li, T., Ed., and S. Hares, Ed., "A 601 Border Gateway Protocol 4 (BGP-4)", RFC 4271, 602 DOI 10.17487/RFC4271, January 2006, 603 . 605 [RFC7880] Pignataro, C., Ward, D., Akiya, N., Bhatia, M., and S. 606 Pallagatti, "Seamless Bidirectional Forwarding Detection 607 (S-BFD)", RFC 7880, DOI 10.17487/RFC7880, July 2016, 608 . 610 [RFC7911] Walton, D., Retana, A., Chen, E., and J. Scudder, 611 "Advertisement of Multiple Paths in BGP", RFC 7911, 612 DOI 10.17487/RFC7911, July 2016, 613 . 615 [RFC7947] Jasinska, E., Hilliard, N., Raszuk, R., and N. Bakker, 616 "Internet Exchange BGP Route Server", RFC 7947, 617 DOI 10.17487/RFC7947, September 2016, 618 . 620 [RFC8342] Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K., 621 and R. Wilton, "Network Management Datastore Architecture 622 (NMDA)", RFC 8342, DOI 10.17487/RFC8342, March 2018, 623 . 625 Authors' Addresses 627 Enke Chen 628 Palo Alto Networks 630 Email: enchen@paloaltonetworks.com 631 Naiming Shen 632 Zededa 634 Email: naiming@zededa.com 636 Robert Raszuk 637 NTT Network Innovations 638 940 Stewart Dr 639 Sunnyvale, CA 94085 640 United States of America 642 Email: robert@raszuk.net 644 Reshad Rahman 645 Canada 647 Email: reshad@yahoo.com