idnits 2.17.1 draft-ietf-i2rs-traceability-06.txt: Checking boilerplate required by RFC 5378 and the IETF Trust (see https://trustee.ietf.org/license-info): ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/1id-guidelines.txt: ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/checklist : ---------------------------------------------------------------------------- -- The document has examples using IPv4 documentation addresses according to RFC6890, but does not use any IPv6 documentation addresses. Maybe there should be IPv6 examples, too? Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year -- The document date (January 4, 2016) is 3034 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(See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) == Outdated reference: A later version (-15) exists of draft-ietf-i2rs-architecture-07 ** Downref: Normative reference to an Informational draft: draft-ietf-i2rs-architecture (ref. 'I-D.ietf-i2rs-architecture') == Outdated reference: A later version (-11) exists of draft-ietf-i2rs-problem-statement-04 ** Downref: Normative reference to an Informational draft: draft-ietf-i2rs-problem-statement (ref. 'I-D.ietf-i2rs-problem-statement') == Outdated reference: A later version (-09) exists of draft-ietf-i2rs-pub-sub-requirements-03 ** Downref: Normative reference to an Informational draft: draft-ietf-i2rs-pub-sub-requirements (ref. 'I-D.ietf-i2rs-pub-sub-requirements') == Outdated reference: A later version (-17) exists of draft-ietf-i2rs-rib-info-model-08 -- Obsolete informational reference (is this intentional?): RFC 6536 (Obsoleted by RFC 8341) Summary: 3 errors (**), 0 flaws (~~), 5 warnings (==), 3 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 I2RS J. Clarke 3 Internet-Draft G. Salgueiro 4 Intended status: Standards Track C. Pignataro 5 Expires: July 7, 2016 Cisco 6 January 4, 2016 8 Interface to the Routing System (I2RS) Traceability: Framework and 9 Information Model 10 draft-ietf-i2rs-traceability-06 12 Abstract 14 This document describes a framework for traceability in the Interface 15 to the Routing System (I2RS) and information model for that 16 framework. It specifies the motivation, requirements, use cases, and 17 defines an information model for recording interactions between 18 elements implementing the I2RS protocol. This framework provides a 19 consistent tracing interface for components implementing the I2RS 20 architecture to record what was done, by which component, and when. 21 It aims to improve the management of I2RS implementations, and can be 22 used for troubleshooting, auditing, forensics, and accounting 23 purposes. 25 Status of This Memo 27 This Internet-Draft is submitted in full conformance with the 28 provisions of BCP 78 and BCP 79. 30 Internet-Drafts are working documents of the Internet Engineering 31 Task Force (IETF). Note that other groups may also distribute 32 working documents as Internet-Drafts. The list of current Internet- 33 Drafts is at http://datatracker.ietf.org/drafts/current/. 35 Internet-Drafts are draft documents valid for a maximum of six months 36 and may be updated, replaced, or obsoleted by other documents at any 37 time. It is inappropriate to use Internet-Drafts as reference 38 material or to cite them other than as "work in progress." 40 This Internet-Draft will expire on July 7, 2016. 42 Copyright Notice 44 Copyright (c) 2016 IETF Trust and the persons identified as the 45 document authors. All rights reserved. 47 This document is subject to BCP 78 and the IETF Trust's Legal 48 Provisions Relating to IETF Documents 49 (http://trustee.ietf.org/license-info) in effect on the date of 50 publication of this document. Please review these documents 51 carefully, as they describe your rights and restrictions with respect 52 to this document. Code Components extracted from this document must 53 include Simplified BSD License text as described in Section 4.e of 54 the Trust Legal Provisions and are provided without warranty as 55 described in the Simplified BSD License. 57 Table of Contents 59 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 60 2. Terminology and Conventions . . . . . . . . . . . . . . . . . 3 61 3. Motivation . . . . . . . . . . . . . . . . . . . . . . . . . 3 62 4. Use Cases . . . . . . . . . . . . . . . . . . . . . . . . . . 3 63 5. Information Model . . . . . . . . . . . . . . . . . . . . . . 4 64 5.1. I2RS Traceability Framework . . . . . . . . . . . . . . . 4 65 5.2. I2RS Trace Log Mandatory Fields . . . . . . . . . . . . . 6 66 5.3. End of Message Marker . . . . . . . . . . . . . . . . . . 8 67 6. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . 8 68 7. Operational Guidance . . . . . . . . . . . . . . . . . . . . 9 69 7.1. Trace Log Creation . . . . . . . . . . . . . . . . . . . 9 70 7.2. Trace Log Temporary Storage . . . . . . . . . . . . . . . 9 71 7.3. Trace Log Rotation . . . . . . . . . . . . . . . . . . . 10 72 7.4. Trace Log Retrieval . . . . . . . . . . . . . . . . . . . 10 73 7.4.1. Retrieval Via Syslog . . . . . . . . . . . . . . . . 10 74 7.4.2. Retrieval Via I2RS Information Collection . . . . . . 11 75 7.4.3. Retrieval Via I2RS Pub-Sub . . . . . . . . . . . . . 11 76 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11 77 9. Security Considerations . . . . . . . . . . . . . . . . . . . 11 78 10. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 12 79 11. References . . . . . . . . . . . . . . . . . . . . . . . . . 12 80 11.1. Normative References . . . . . . . . . . . . . . . . . . 12 81 11.2. Informative References . . . . . . . . . . . . . . . . . 12 82 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 13 84 1. Introduction 86 The architecture for the Interface to the Routing System 87 ([I-D.ietf-i2rs-architecture]) specifies that I2RS Clients wishing to 88 retrieve or change routing state on a routing element MUST 89 authenticate to an I2RS Agent. The I2RS Client will have a unique 90 identity it provides for authentication, and should provide another, 91 opaque identity for applications communicating through it. The 92 programming of routing state will produce a return code containing 93 the results of the specified operation and associated reason(s) for 94 the result. All of this is critical information to be used for 95 understanding the history of I2RS interactions. 97 This document describes use cases for I2RS traceability. Based on 98 these use cases, the document proposes an information model and 99 reporting requirements to provide for effective recording of I2RS 100 interactions. In this context, effective troubleshooting means being 101 able to identify what operation was performed by a specific I2RS 102 Client, what was the result of the operation, and when that operation 103 was performed. 105 Discussions about the retention of the data logged as part of I2RS 106 traceability, while important, are outside of the scope of this 107 document. 109 2. Terminology and Conventions 111 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 112 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 113 document are to be interpreted as described in [RFC2119]. 115 The architecture specification for I2RS [I-D.ietf-i2rs-architecture] 116 defines additional terms used in this document that are specific to 117 the I2RS domain, such as "I2RS Agent", "I2RS Client", etc. The 118 reader is expected to be familiar with the terminology and concepts 119 defined in [I-D.ietf-i2rs-architecture]. 121 The IP addresses used in the example in this document correspond to 122 the documentation address blocks 192.0.2.0/24 (TEST-NET-1), 123 198.51.100.0/24 (TEST-NET-2) and 203.0.113.0/24 (TEST-NET-3) as 124 described in [RFC5737]. 126 3. Motivation 128 As networks scale and policy becomes an increasingly important part 129 of the control plane that creates and maintains the forwarding state, 130 operational complexity increases as well. I2RS offers more granular 131 and coherent control over policy and control plane state, but it also 132 removes or reduces the locality of the policy that has been applied 133 to the control plane at any individual forwarding device. The 134 ability to automate and abstract even complex policy-based controls 135 highlights the need for an equally scalable traceability function to 136 provide event-level granularity of the routing system compliant with 137 the requirements of I2RS (Section 5 of 138 [I-D.ietf-i2rs-problem-statement]). 140 4. Use Cases 142 An obvious motivation for I2RS traceability is the need to 143 troubleshoot and identify root-causes of problems in these 144 increasingly complex routing systems. For example, since I2RS is a 145 high-throughput multi-channel, full duplex and highly responsive 146 interface, I2RS Clients may be performing a large number of 147 operations on I2RS Agents concurrently or at nearly the same time and 148 quite possibly in very rapid succession. As these many changes are 149 made, the network reacts accordingly. These changes might lead to a 150 race condition, performance issues, data loss, or disruption of 151 services. In order to isolate the root cause of these issues it is 152 critical that a network operator or administrator has visibility into 153 what changes were made via I2RS at a specific time. 155 Some network environments have strong auditing requirements for 156 configuration and runtime changes. Other environments have policies 157 that require saving logging information for operational or regulatory 158 compliance considerations. These requirements therefore demand that 159 I2RS provides an account of changes made to network element routing 160 systems. 162 As I2RS becomes increasingly pervasive in routing environments, a 163 traceability model offers significant advantages and facilitates the 164 following use cases: 166 o Automated event correlation, trend analysis, and anomaly 167 detection; 169 o Trace log storage for offline (manual or tools) analysis; 171 o Improved accounting of routing system operations; 173 o Standardized structured data format for writing common tools; 175 o Common reference for automated testing and incident reporting; 177 o Real-time monitoring and troubleshooting; 179 o Enhanced network audit, management and forensic analysis 180 capabilities. 182 5. Information Model 184 5.1. I2RS Traceability Framework 186 This section describes a framework for I2RS traceability based on the 187 I2RS Architecture. Some notable elements on the architecture are in 188 this section. 190 The interaction between the optional northbound application, I2RS 191 Client, I2RS Agent, the Routing System and the data captured in the 192 I2RS trace log is shown in Figure 1. 194 +----------------+ 195 |Application | 196 |.............. | 197 | Application ID | 198 +----------------+ 199 ^ 200 | 0 .. N 201 | 202 V 203 +-------------+ 204 |I2RS Client | 205 |.............| 206 | Client ID | 207 +-------------+ 208 ^ 209 | 1 .. N 210 | 211 V 212 +-------------+ +-----------------------------+ 213 |I2RS Agent |---------------->|Trace Log | 214 | | |.............................| 215 +-------------+ |Log Entry [1 .. N] | 216 ^ |.............................| 217 | |Request Timestamp | 218 | |Client ID | 219 | |Client Priority | 220 | ^ |Secondary ID | 221 Operation + | Result Code |Client Address | 222 Op Data | |Requested Operation | 223 V | |Applied Operation | 224 | |Operation Data Present | 225 | |Requested Operation Data | 226 | |Applied Operation Data | 227 | |Transaction ID | 228 | |Result Code | 229 | |Result Timestamp | 230 V |End Of Message | 231 +-------------+ +-----------------------------+ 232 |Routing | 233 |System | 234 +-------------+ 236 Figure 1: I2RS Interaction Trace Log Capture 238 5.2. I2RS Trace Log Mandatory Fields 240 In order to ensure that each I2RS interaction can be properly traced 241 back to the Client that made the request at a specific point in time, 242 the following information MUST be collected and stored by the Agent. 244 The list below describes the fields captured in the I2RS trace log. 246 Entry ID: This is a unique identifier for each entry in the I2RS 247 trace log. Since multiple operations can occur from the same 248 Client at the same time, it is important to have an identifier 249 that can be unambiguously associated to a specific entry. 251 Request Timestamp: The specific time at which the I2RS operation 252 was received by the Agent. The time is passed in the [RFC3339] 253 format. Given that many I2RS operations can occur in rapid 254 succession, the use of fractional seconds MUST be used to provide 255 adequate granularity. Fractional seconds SHOULD be expressed 256 using human-readable 32-bit second and 32-bit microsecond 257 granularity in second.microsecond format. 259 Client Identity: The I2RS Client identity used to authenticate the 260 Client to the I2RS Agent. 262 Client Priority: The I2RS Client priority assigned by the access 263 control model that authenticates the Client. For example, this 264 can be set by the NETCONF Access Control Model (NACM) as described 265 in [RFC6536]. 267 Secondary Identity: This is an opaque identity that may be known to 268 the Client from a northbound controlling application. This is 269 used to trace the northbound application driving the actions of 270 the Client. The Client may not provide this identity to the Agent 271 if there is no external application driving the Client. However, 272 this field MUST be logged. If the Client does not provide an 273 application ID, then the Agent MUST log an UNAVAILABLE value in 274 the field. 276 Client Address: This is the network address of the Client that 277 connected to the Agent. For example, this may be an IPv4 or IPv6 278 address. [Note: will I2RS support interactions that have no 279 network address? If so this field will need to be updated.] 281 Requested Operation: This is the I2RS operation that was requested 282 to be performed. For example, this may be an add route operation 283 if a route is being inserted into a routing table. This may not 284 be the operation that was actually applied to the Agent. 286 Applied Operation: This is the I2RS operation that was actually 287 performed. This can differ from the Requested Operation in cases 288 where the Agent cannot satisfy the Requested Operation. 290 Operation Data Present: This is a Boolean field that indicates 291 whether or not addition per-Operation Data is present. 293 Requested Operation Data: This field comprises the data passed to 294 the Agent to complete the desired operation. For example, if the 295 operation is a route add operation, the Operation Data would 296 include the route prefix, prefix length, and next hop information 297 to be inserted as well as the specific routing table to which the 298 route will be added. The operation data can also include 299 interface information. If Operation Data is provided, then the 300 Operation Data Present field MUST be set to TRUE. Some operations 301 may not provide operation data. In those cases, the Operation 302 Data Present field MUST be set to FALSE, and this field MUST be 303 empty. This may not represent the data that was used for the 304 operation that was actually applied on the Agent. 306 Applied Operation Data: This field comprises the data that was 307 actually applied as part of the Applied Operation. If the Agent 308 cannot satisfy the Requested Operation with the Requested 309 Operation Data, then this field can differ from the Requested 310 Operation Data. 312 Transaction ID: The Transaction Identity is an opaque string that 313 represents this particular operation is part of a long-running 314 I2RS transaction that can consist of multiple, related I2RS 315 operations. Using this value, one can relate multiple log entries 316 together as they are part of a single, overall I2RS operation. 317 [NOTE: The requirements for transactions and long-running requests 318 are being discussed in the NETCONF working group, and this text 319 will follow the requirements set forth there.] 321 Result Code: This field holds the result of the operation. In the 322 case of RIB operations, this MUST be the return code as specified 323 in Section 4 of [I-D.ietf-i2rs-rib-info-model]. The operation may 324 not complete with a result code in the case of a timeout. If the 325 operation fails to complete, it MUST still log the attempted 326 operation with an appropriate result code (e.g., a result code 327 indicating a timeout). 329 Result Timestamp: The specific time at which the I2RS operation was 330 completed by the Agent. The time is passed in the [RFC3339] 331 format. If the operation timed out, then this field will contain 332 an all-zeroes value of "0000-00-00T00:00:00.00". Given that many 333 I2RS operations can occur in rapid succession, the use of 334 fractional seconds MUST be used to provide adequate granularity. 335 Fractional seconds SHOULD be expressed using human-readable 32-bit 336 second and 32-bit microsecond granularity in second.microsecond 337 format. 339 End Of Message: Each log entry SHOULD have an appropriate End Of 340 Message (EOM) indicator. See section Section 5.3 below for more 341 details. 343 5.3. End of Message Marker 345 Because of variability within I2RS trace log fields, implementors 346 MUST use a format-appropriate end of message (EOM) indicator in order 347 to signify the end of a particular record. That is, regardless of 348 format, the I2RS trace log MUST provide a distinct way of 349 distinguishing between the end of one record and the beginning of 350 another. For example, in a linear formated log (similar to syslog) 351 the EOM marker may be a newline character. In an XML formated log, 352 the schema would provide for element tags that denote beginning and 353 end of records. In a JSON formated log, the syntax would provide 354 record separation (likely by comma-separated array elements). 356 6. Examples 358 Here is a proposed sample of what the fields might look like in an 359 I2RS trace log. This is only an early proposal. These values are 360 subject to change. 362 Entry ID: 1 363 Request Timestamp: 2013-09-03T12:00:01.21+00:00 364 Client ID: 5CEF1870-0326-11E2-A21F-0800200C9A66 365 Client Priority: 100 366 Secondary ID com.example.RoutingApp 367 Client Address: 192.0.2.2 368 Requested Operation: ROUTE_ADD 369 Applied Operation: ROUTE_ADD 370 Operation Data Present: TRUE 371 Requested Operation Data: PREFIX 203.0.113.0 PREFIX-LEN 24 NEXT-HOP 372 198.51.100.1 373 Applied Operation Data: PREFIX 203.0.113.0 PREFIX-LEN 24 NEXT-HOP 374 198.51.100.1 375 Transaction ID: 2763461 376 Result Code: SUCCESS(0) 377 Result Timestamp: 2013-09-03T12:00:01.23+00:00 379 7. Operational Guidance 381 Specific operational procedures regarding temporary log storage, 382 rollover, retrieval, and access of I2RS trace logs is out of scope 383 for this document. Organizations employing I2RS trace logging are 384 responsible for establishing proper operational procedures that are 385 appropriately suited to their specific requirements and operating 386 environment. In this section we only provide fundamental and 387 generalized operational guidelines that are implementation- 388 independent. 390 7.1. Trace Log Creation 392 The I2RS Agent interacts with the Routing and Signaling functions of 393 the Routing Element. Since the I2RS Agent is responsible for 394 actually making the routing changes on the associated network device, 395 it creates and maintains a log of operations that can be retrieved to 396 troubleshoot I2RS-related impact to the network. 398 7.2. Trace Log Temporary Storage 400 The trace information may be temporarily stored either in an in- 401 memory buffer or as a file local to the Agent. Care should be given 402 to the number of I2RS operations expected on a given Agent so that 403 the appropriate storage medium is used and to maximize the 404 effectiveness of the log while not impacting the performance and 405 health of the Agent. Client requests may not always be processed 406 synchronously or within a bounded time period. Consequently, to 407 ensure that trace log fields, such as "Operation" and "Result Code", 408 are part of the same trace log record it may require buffering of the 409 trace log entries. This buffering may result in additional resource 410 load on the Agent and the network element. 412 Section 7.3 discusses rotating the trace log in order to preserve the 413 operation history without exhausting Agent or network device 414 resources. It is perfectly acceptable, therefore, to use both an in- 415 memory buffer for recent operations while rotating or archiving older 416 operations to a local file. 418 It is outside the scope of this document to specify the 419 implementation details (i.e., size, throughput, data protection, 420 privacy, etc.) for the physical storage of the I2RS log file. Data 421 retention policies of the I2RS traceability log is also outside the 422 scope of this document. 424 7.3. Trace Log Rotation 426 In order to prevent the exhaustion of resources on the I2RS Agent or 427 its associated network device, it is RECOMMENDED that the I2RS Agent 428 implements trace log rotation. The details on how this is achieved 429 are left to the implementation and outside the scope of this 430 document. However, it should be possible to do file rotation based 431 on either time or size of the current trace log. If file rollover is 432 supported, multiple archived log files should be supported in order 433 to maximize the troubleshooting and accounting benefits of the trace 434 log. 436 7.4. Trace Log Retrieval 438 Implementors are free to provide their own, proprietary interfaces 439 and develop custom tools to retrieve and display the I2RS trace log. 440 These may include the display of the I2RS trace log as Command Line 441 Interface (CLI) output. However, a key intention of defining this 442 information model is to establish an vendor-agnostic and consistent 443 interface to collect I2RS trace data. Correspondingly, retrieval of 444 the data should also be made vendor-agnostic. 446 Despite the fact that export of I2RS trace log information could be 447 an invaluable diagnostic tool for off-box analysis, exporting this 448 information MUST NOT interfere with the ability of the Agent to 449 process new incoming operations. 451 The following three sections describe potential ways the trace log 452 can be accessed. At least one of these three MUST be used, with the 453 I2RS mechanisms being preferred as they are vendor-independent 454 approaches to retrieving the data. 456 7.4.1. Retrieval Via Syslog 458 The syslog protocol [RFC5424] is a standard way of sending event 459 notification messages from a host to a collector. However, the 460 protocol does not define any standard format for storing the 461 messages, and thus implementors of I2RS tracing would be left to 462 define their own format. So, while the data contained within the 463 syslog message would adhere to this information model, and may be 464 consumable by a human operator, it would not be easily parseable by a 465 machine. Therefore, syslog MAY be employed as a means of retrieving 466 or disseminating the I2RS trace log contents. 468 If syslog is used for trace log retrieval, then existing logging 469 infrastructure and capabilities of syslog [RFC5424] should be 470 leveraged without the need to define or extend existing formats. For 471 example, the various fields described in Section 5.2 SHOULD be 472 modeled and encoded as Structured Data Elements (referred to as "SD- 473 ELEMENT"), as described in Section 6.3.1 of [RFC5424]. 475 7.4.2. Retrieval Via I2RS Information Collection 477 Section 6.7 of the I2RS architecture [I-D.ietf-i2rs-architecture] 478 defines a mechanism for information collection. The information 479 collected includes obtaining a snapshot of a large amount of data 480 from the network element. It is the intent of I2RS to make this data 481 available in an implementor-agnostic fashion. Therefore, the I2RS 482 trace log SHOULD be made available via the I2RS information 483 collection mechanism either as a single snapshot or via a 484 subscription stream. 486 7.4.3. Retrieval Via I2RS Pub-Sub 488 Section 7.6 of the I2RS architecture [I-D.ietf-i2rs-architecture] 489 goes on to describe notification mechanisms for a feed of changes 490 happening within the I2RS layer. Specifically, the requirements for 491 a publish-subscribe system for I2RS are defined in 492 [I-D.ietf-i2rs-pub-sub-requirements]. I2RS Agents SHOULD support 493 publishing I2RS trace log information to that feed as described in 494 that document. Subscribers would then receive a live stream of I2RS 495 interactions in trace log format and could flexibly choose to do a 496 number of things with the log messages. For example, the subscribers 497 could log the messages to a datastore, aggregate and summarize 498 interactions from a single Client, etc. The full range of potential 499 activites is virtually limitless and the details of how they are 500 performed are outside the scope of this document, however. 502 8. IANA Considerations 504 This document makes no request of IANA. 506 9. Security Considerations 508 The I2RS trace log, like any log file, reveals the state of the 509 entity producing it as well as the identifying information elements 510 and detailed interactions of the system containing it. The 511 information model described in this document does not itself 512 introduce any security issues, but it does define the set of 513 attributes that make up an I2RS log file. These attributes may 514 contain sensitive information and thus should adhere to the security, 515 privacy and permission policies of the organization making use of the 516 I2RS log file. 518 It is outside the scope of this document to specify how to protect 519 the stored log file, but it is expected that adequate precautions and 520 security best practices such as disk encryption, appropriately 521 restrictive file/directory permissions, suitable hardening and 522 physical security of logging entities, mutual authentication, 523 transport encryption, channel confidentiality, and channel integrity 524 if transferring log files. Additionally, the potentially sensitive 525 information contained in a log file SHOULD be adequately anonymized 526 or obfuscated by operators to ensure its privacy. 528 10. Acknowledgments 530 The authors would like to thank Alia Atlas for her initial feedback 531 and overall support for this work. Additionally, the authors 532 acknowledge Alvaro Retana, Russ White, Matt Birkner, Jeff Haas, Joel 533 Halpern, Dean Bogdanovich, Ignas Bagdonas, Nobo Akiya, Kwang-koog 534 Lee, and Alex Clemm for their reviews, contributed text, and 535 suggested improvements to this document. 537 11. References 539 11.1. Normative References 541 [I-D.ietf-i2rs-architecture] 542 Atlas, A., Halpern, J., Hares, S., Ward, D., and T. 543 Nadeau, "An Architecture for the Interface to the Routing 544 System", draft-ietf-i2rs-architecture-07 (work in 545 progress), December 2014. 547 [I-D.ietf-i2rs-problem-statement] 548 Atlas, A., Nadeau, T., and D. Ward, "Interface to the 549 Routing System Problem Statement", draft-ietf-i2rs- 550 problem-statement-04 (work in progress), June 2014. 552 [I-D.ietf-i2rs-pub-sub-requirements] 553 Voit, E., Clemm, A., and A. Prieto, "Requirements for 554 Subscription to YANG Datastores", draft-ietf-i2rs-pub-sub- 555 requirements-03 (work in progress), October 2015. 557 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 558 Requirement Levels", BCP 14, RFC 2119, March 1997. 560 11.2. Informative References 562 [I-D.ietf-i2rs-rib-info-model] 563 Bahadur, N., Kini, S., and J. Medved, "Routing Information 564 Base Info Model", draft-ietf-i2rs-rib-info-model-08 (work 565 in progress), October 2015. 567 [RFC3339] Klyne, G., Ed. and C. Newman, "Date and Time on the 568 Internet: Timestamps", RFC 3339, July 2002. 570 [RFC5424] Gerhards, R., "The Syslog Protocol", RFC 5424, March 2009. 572 [RFC5737] Arkko, J., Cotton, M., and L. Vegoda, "IPv4 Address Blocks 573 Reserved for Documentation", RFC 5737, January 2010. 575 [RFC6536] Bierman, A. and M. Bjorklund, "Network Configuration 576 Protocol (NETCONF) Access Control Model", RFC 6536, March 577 2012. 579 Authors' Addresses 581 Joe Clarke 582 Cisco Systems, Inc. 583 7200-12 Kit Creek Road 584 Research Triangle Park, NC 27709 585 US 587 Phone: +1-919-392-2867 588 Email: jclarke@cisco.com 590 Gonzalo Salgueiro 591 Cisco Systems, Inc. 592 7200-12 Kit Creek Road 593 Research Triangle Park, NC 27709 594 US 596 Email: gsalguei@cisco.com 598 Carlos Pignataro 599 Cisco Systems, Inc. 600 7200-12 Kit Creek Road 601 Research Triangle Park, NC 27709 602 US 604 Email: cpignata@cisco.com