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Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Global Routing Operations T. Evens 3 Internet-Draft S. Bayraktar 4 Updates: 7854 (if approved) Cisco Systems 5 Intended status: Standards Track P. Lucente 6 Expires: February 6, 2020 NTT Communications 7 P. Mi 8 Tencent 9 S. Zhuang 10 Huawei 11 August 5, 2019 13 Support for Adj-RIB-Out in BGP Monitoring Protocol (BMP) 14 draft-ietf-grow-bmp-adj-rib-out-07 16 Abstract 18 The BGP Monitoring Protocol (BMP) defines access to only the Adj-RIB- 19 In Routing Information Bases (RIBs). This document updates the BGP 20 Monitoring Protocol (BMP) RFC 7854 by adding access to the Adj-RIB- 21 Out RIBs. It adds a new flag to the peer header to distinguish Adj- 22 RIB-In and Adj-RIB-Out. 24 Status of This Memo 26 This Internet-Draft is submitted in full conformance with the 27 provisions of BCP 78 and BCP 79. 29 Internet-Drafts are working documents of the Internet Engineering 30 Task Force (IETF). Note that other groups may also distribute 31 working documents as Internet-Drafts. The list of current Internet- 32 Drafts is at https://datatracker.ietf.org/drafts/current/. 34 Internet-Drafts are draft documents valid for a maximum of six months 35 and may be updated, replaced, or obsoleted by other documents at any 36 time. It is inappropriate to use Internet-Drafts as reference 37 material or to cite them other than as "work in progress." 39 This Internet-Draft will expire on February 6, 2020. 41 Copyright Notice 43 Copyright (c) 2019 IETF Trust and the persons identified as the 44 document authors. All rights reserved. 46 This document is subject to BCP 78 and the IETF Trust's Legal 47 Provisions Relating to IETF Documents 48 (https://trustee.ietf.org/license-info) in effect on the date of 49 publication of this document. Please review these documents 50 carefully, as they describe your rights and restrictions with respect 51 to this document. Code Components extracted from this document must 52 include Simplified BSD License text as described in Section 4.e of 53 the Trust Legal Provisions and are provided without warranty as 54 described in the Simplified BSD License. 56 Table of Contents 58 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 59 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 60 3. Definitions . . . . . . . . . . . . . . . . . . . . . . . . . 3 61 4. Per-Peer Header . . . . . . . . . . . . . . . . . . . . . . . 4 62 5. Adj-RIB-Out . . . . . . . . . . . . . . . . . . . . . . . . . 4 63 5.1. Post-Policy . . . . . . . . . . . . . . . . . . . . . . . 4 64 5.2. Pre-Policy . . . . . . . . . . . . . . . . . . . . . . . 5 65 6. BMP Messages . . . . . . . . . . . . . . . . . . . . . . . . 5 66 6.1. Route Monitoring and Route Mirroring . . . . . . . . . . 5 67 6.2. Statistics Report . . . . . . . . . . . . . . . . . . . . 5 68 6.3. Peer Down and Up Notifications . . . . . . . . . . . . . 6 69 6.3.1. Peer Up Information . . . . . . . . . . . . . . . . . 6 70 7. Other Considerations . . . . . . . . . . . . . . . . . . . . 6 71 7.1. Peer and Update Groups . . . . . . . . . . . . . . . . . 7 72 8. Security Considerations . . . . . . . . . . . . . . . . . . . 7 73 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7 74 9.1. BMP Peer Flags . . . . . . . . . . . . . . . . . . . . . 8 75 9.2. BMP Statistics Types . . . . . . . . . . . . . . . . . . 8 76 9.3. Peer Up Information TLV . . . . . . . . . . . . . . . . . 8 77 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 9 78 10.1. Normative References . . . . . . . . . . . . . . . . . . 9 79 10.2. URIs . . . . . . . . . . . . . . . . . . . . . . . . . . 9 80 Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 9 81 Contributors . . . . . . . . . . . . . . . . . . . . . . . . . . 9 82 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 10 84 1. Introduction 86 BGP Monitoring Protocol (BMP) defines monitoring of the received 87 (e.g., Adj-RIB-In) Routing Information Bases (RIBs) per peer. The 88 Adj-RIB-In pre-policy conveys to a BMP receiver all RIB data before 89 any policy has been applied. The Adj-RIB-In post-policy conveys to a 90 BMP receiver all RIB data after policy filters and/or modifications 91 have been applied. An example of pre-policy versus post-policy is 92 when an inbound policy applies attribute modification or filters. 93 Pre-policy would contain information prior to the inbound policy 94 changes or filters of data. Post policy would convey the changed 95 data or would not contain the filtered data. 97 Monitoring the received updates that the router received before any 98 policy has been applied is the primary level of monitoring for most 99 use-cases. Inbound policy validation and auditing is the primary 100 use-case for enabling post-policy monitoring. 102 In order for a BMP receiver to receive any BGP data, the BMP sender 103 (e.g., router) needs to have an established BGP peering session and 104 actively be receiving updates for an Adj-RIB-In. 106 Being able to only monitor the Adj-RIB-In puts a restriction on what 107 data is available to BMP receivers via BMP senders (e.g., routers). 108 This is an issue when the receiving end of the BGP peer is not 109 enabled for BMP or when it is not accessible for administrative 110 reasons. For example, a service provider advertises prefixes to a 111 customer, but the service provider cannot see what it advertises via 112 BMP. Asking the customer to enable BMP and monitoring of the Adj- 113 RIB-In is not feasible. 115 BGP Monitoring Protocol (BMP) RFC 7854 [RFC7854] only defines Adj- 116 RIB-In being sent to BMP receivers. This document updates the per- 117 peer header in section 4.2 of [RFC7854] by adding a new flag to 118 distinguish Adj-RIB-In versus Adj-RIB-Out. BMP senders use the new 119 flag to send either Adj-RIB-In or Adj-RIB-Out. 121 Adding Adj-RIB-Out provides the ability for a BMP sender to send to 122 BMP receivers what it advertises to BGP peers, which can be used for 123 outbound policy validation and to monitor routes that were 124 advertised. 126 2. Terminology 128 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 129 "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and 130 "OPTIONAL" in this document are to be interpreted as described in BCP 131 14 RFC 2119 [RFC2119] RFC 8174 [RFC8174] when, and only when, they 132 appear in all capitals, as shown here. 134 3. Definitions 136 o Adj-RIB-Out: As defined in [RFC4271], "The Adj-RIBs-Out contains 137 the routes for advertisement to specific peers by means of the 138 local speaker's UPDATE messages." 140 o Pre-Policy Adj-RIB-Out: The result before applying the outbound 141 policy to an Adj-RIB-Out. This normally would match what is in the 142 local RIB. 144 o Post-Policy Adj-RIB-Out: The result of applying outbound policy to 145 an Adj-RIB-Out. This MUST convey to the BMP receiver what is 146 actually transmitted to the peer. 148 4. Per-Peer Header 150 The per-peer header has the same structure and flags as defined in 151 section 4.2 of [RFC7854] with the following O flag addition: 153 0 1 2 3 4 5 6 7 154 +-+-+-+-+-+-+-+-+ 155 |V|L|A|O| Resv | 156 +-+-+-+-+-+-+-+-+ 158 o The O flag indicates Adj-RIB-In if set to 0 and Adj-RIB-Out if set 159 to 1. 161 The existing flags are defined in section 4.2 of [RFC7854] and the 162 remaining bits are reserved for future use. They MUST be transmitted 163 as 0 and their values MUST be ignored on receipt. 165 When the O flag is set to 1, the following fields in the Per-Peer 166 Header are redefined: 168 o Peer Address: The remote IP address associated with the TCP 169 session over which the encapsulated PDU is sent. 171 o Peer AS: The Autonomous System number of the peer to which the 172 encapsulated PDU is sent. 174 o Peer BGP ID: The BGP Identifier of the peer to which the 175 encapsulated PDU is sent. 177 o Timestamp: The time when the encapsulated routes were advertised 178 (one may also think of this as the time when they were installed 179 in the Adj-RIB-Out), expressed in seconds and microseconds since 180 midnight (zero hour), January 1, 1970 (UTC). If zero, the time is 181 unavailable. Precision of the timestamp is implementation- 182 dependent. 184 5. Adj-RIB-Out 186 5.1. Post-Policy 188 The primary use-case in monitoring Adj-RIB-Out is to monitor the 189 updates transmitted to a BGP peer after outbound policy has been 190 applied. These updates reflect the result after modifications and 191 filters have been applied (e.g., Adj-RIB-Out Post-Policy). Some 192 attributes are set when the BGP message is transmitted, such as next- 193 hop. Adj-RIB-Out Post-Policy MUST convey to the BMP receiver what is 194 actually transmitted to the peer. 196 The L flag MUST be set to 1 to indicate post-policy. 198 5.2. Pre-Policy 200 Similarly to Adj-RIB-In policy validation, pre-policy Adj-RIB-Out can 201 be used to validate and audit outbound policies. For example, a 202 comparison between pre-policy and post-policy can be used to validate 203 the outbound policy. 205 Depending on BGP peering session type (IBGP, IBGP route reflector 206 client, EBGP, BGP confederations, Route Server Client) the candidate 207 routes that make up the Pre-Policy Adj-RIB-Out do not contain all 208 local-rib routes. Pre-Policy Adj-RIB-Out conveys only routes that 209 are available based on the peering type. Post-Policy represents the 210 filtered/changed routes from the available routes. 212 Some attributes are set only during transmission of the BGP message, 213 i.e., Post-Policy. It is common that next-hop may be null, loopback, 214 or similar during pre-policy phase. All mandatory attributes, such 215 as next-hop, MUST be either ZERO or have an empty length if they are 216 unknown at the Pre-Policy phase completion. The BMP receiver will 217 treat zero or empty mandatory attributes as self-originated. 219 The L flag MUST be set to 0 to indicate pre-policy. 221 6. BMP Messages 223 Many BMP messages have a per-peer header but some are not applicable 224 to Adj-RIB-In or Adj-RIB-Out monitoring, such as peer up and down 225 notifications. Unless otherwise defined, the O flag should be set to 226 0 in the per-peer header in BMP messages. 228 6.1. Route Monitoring and Route Mirroring 230 The O flag MUST be set accordingly to indicate if the route monitor 231 or route mirroring message conveys Adj-RIB-In or Adj-RIB-Out. 233 6.2. Statistics Report 235 The Statistics report message has a Stat Type field to indicate the 236 statistic carried in the Stat Data field. Statistics report messages 237 are not specific to Adj-RIB-In or Adj-RIB-Out and MUST have the O 238 flag set to zero. The O flag SHOULD be ignored by the BMP receiver. 240 The following new statistic types are added: 242 o Stat Type = 14: (64-bit Gauge) Number of routes in Adj-RIBs-Out 243 Pre-Policy. 245 o Stat Type = 15: (64-bit Gauge) Number of routes in Adj-RIBs-Out 246 Post-Policy. 248 o Stat Type = 16: Number of routes in per-AFI/SAFI Adj-RIB-Out Pre- 249 Policy. The value is structured as: 2-byte Address Family 250 Identifier (AFI), 1-byte Subsequent Address Family Identifier 251 (SAFI), followed by a 64-bit Gauge. 253 o Stat Type = 17: Number of routes in per-AFI/SAFI Adj-RIB-Out Post- 254 Policy. The value is structured as: 2-byte Address Family 255 Identifier (AFI), 1-byte Subsequent Address Family Identifier 256 (SAFI), followed by a 64-bit Gauge. 258 6.3. Peer Down and Up Notifications 260 Peer Up and Down notifications convey BGP peering session state to 261 BMP receivers. The state is independent of whether or not route 262 monitoring or route mirroring messages will be sent for Adj-RIB-In, 263 Adj-RIB-Out, or both. BMP receiver implementations SHOULD ignore the 264 O flag in Peer Up and Down notifications. 266 6.3.1. Peer Up Information 268 The following Peer Up message Information TLV type is added: 270 o Type = 4: Admin Label. The Information field contains a free-form 271 UTF-8 string whose byte length is given by the Information Length 272 field. The value is administratively assigned. There is no 273 requirement to terminate the string with null or any other 274 character. 276 Multiple admin labels can be included in the Peer Up notification. 277 When multiple admin labels are included the BMP receiver MUST 278 preserve their order. 280 The TLV is optional. 282 7. Other Considerations 283 7.1. Peer and Update Groups 285 Peer and update groups are used to group updates shared by many 286 peers. This is a level of efficiency in implementations, not a true 287 representation of what is conveyed to a peer in either Pre-Policy or 288 Post-Policy. 290 One of the use-cases to monitor Adj-RIB-Out Post-Policy is to 291 validate and continually ensure the egress updates match what is 292 expected. For example, wholesale peers should never have routes with 293 community X:Y sent to them. In this use-case, there may be hundreds 294 of wholesale peers but a single peer could have represented the 295 group. 297 From a BMP perspective, this should be simple to include a group name 298 in the Peer Up, but it is more complex than that. BGP 299 implementations have evolved to provide comprehensive and structured 300 policy grouping, such as session, AFI/SAFI, and template-based based 301 group policy inheritances. 303 This level of structure and inheritance of polices does not provide a 304 simple peer group name or ID, such as wholesale peer. 306 Instead of requiring a group name to be used, a new administrative 307 label informational TLV (Section 6.3.1) is added to the Peer Up 308 message. These labels have administrative scope relevance. For 309 example, labels "type=wholesale" and "region=west" could be used to 310 monitor expected policies. 312 Configuration and assignment of labels to peers is BGP implementation 313 specific. 315 8. Security Considerations 317 The same considerations as in section 11 of [RFC7854] apply to this 318 document. Implementations of this protocol SHOULD require to 319 establish sessions with authorized and trusted monitoring devices. 320 It is also believed that this document does not add any additional 321 security considerations. 323 9. IANA Considerations 325 This document requests that IANA assign the following new parameters 326 to the BMP parameters name space [1]. 328 9.1. BMP Peer Flags 330 This document defines the following per-peer header flags 331 (Section 4): 333 o Flag 3 as O flag: The O flag indicates Adj-RIB-In if set to 0 and 334 Adj-RIB-Out if set to 1. 336 9.2. BMP Statistics Types 338 This document defines four statistic types for statistics reporting 339 (Section 6.2): 341 o Stat Type = 14: (64-bit Gauge) Number of routes in Adj-RIBs-Out 342 Pre-Policy. 344 o Stat Type = 15: (64-bit Gauge) Number of routes in Adj-RIBs-Out 345 Post-Policy. 347 o Stat Type = 16: Number of routes in per-AFI/SAFI Adj-RIB-Out Pre- 348 Policy. The value is structured as: 2-byte Address Family 349 Identifier (AFI), 1-byte Subsequent Address Family Identifier 350 (SAFI), followed by a 64-bit Gauge. 352 o Stat Type = 17: Number of routes in per-AFI/SAFI Adj-RIB-Out Post- 353 Policy. The value is structured as: 2-byte Address Family 354 Identifier (AFI), 1-byte Subsequent Address Family Identifier 355 (SAFI), followed by a 64-bit Gauge. 357 9.3. Peer Up Information TLV 359 This document defines the following BMP Peer Up Information TLV types 360 (Section 6.3.1): 362 o Type = 4: Admin Label. The Information field contains a free-form 363 UTF-8 string whose byte length is given by the Information Length 364 field. The value is administratively assigned. There is no 365 requirement to terminate the string with null or any other 366 character. 368 Multiple admin labels can be included in the Peer Up notification. 369 When multiple admin labels are included the BMP receiver MUST 370 preserve their order. 372 The TLV is optional. 374 10. References 376 10.1. Normative References 378 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 379 Requirement Levels", BCP 14, RFC 2119, 380 DOI 10.17487/RFC2119, March 1997, 381 . 383 [RFC4271] Rekhter, Y., Ed., Li, T., Ed., and S. Hares, Ed., "A 384 Border Gateway Protocol 4 (BGP-4)", RFC 4271, 385 DOI 10.17487/RFC4271, January 2006, 386 . 388 [RFC7854] Scudder, J., Ed., Fernando, R., and S. Stuart, "BGP 389 Monitoring Protocol (BMP)", RFC 7854, 390 DOI 10.17487/RFC7854, June 2016, 391 . 393 [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 394 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, 395 May 2017, . 397 10.2. URIs 399 [1] https://www.iana.org/assignments/bmp-parameters/bmp- 400 parameters.xhtml 402 Acknowledgements 404 The authors would like to thank John Scudder and Mukul Srivastava for 405 their valuable input. 407 Contributors 409 Manish Bhardwaj 410 Cisco Systems 411 3700 Cisco Way 412 San Jose, CA 95134 413 USA 415 Email: manbhard@cisco.com 417 Xianyuzheng 418 Tencent 419 Tencent Building, Kejizhongyi Avenue, 420 Hi-techPark, Nanshan District,Shenzhen 518057, P.R.China 421 Weiguo 422 Tencent 423 Tencent Building, Kejizhongyi Avenue, 424 Hi-techPark, Nanshan District,Shenzhen 518057, P.R.China 426 Shugang cheng 427 H3C 429 Authors' Addresses 431 Tim Evens 432 Cisco Systems 433 2901 Third Avenue, Suite 600 434 Seattle, WA 98121 435 USA 437 Email: tievens@cisco.com 439 Serpil Bayraktar 440 Cisco Systems 441 3700 Cisco Way 442 San Jose, CA 95134 443 USA 445 Email: serpil@cisco.com 447 Paolo Lucente 448 NTT Communications 449 Siriusdreef 70-72 450 Hoofddorp, WT 2132 451 NL 453 Email: paolo@ntt.net 455 Penghui Mi 456 Tencent 457 Tengyun Building,Tower A ,No. 397 Tianlin Road 458 Shanghai 200233 459 China 461 Email: kevinmi@tencent.com 462 Shunwan Zhuang 463 Huawei 464 Huawei Bld., No.156 Beiqing Rd. 465 Beijing 100095 466 China 468 Email: zhuangshunwan@huawei.com