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Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Network Working Group V. Fuller 3 Internet-Draft D. Farinacci 4 Obsoletes: 6833 (if approved) Cisco Systems 5 Intended status: Standards Track A. Cabellos (Ed.) 6 Expires: January 18, 2019 UPC/BarcelonaTech 7 July 17, 2018 9 Locator/ID Separation Protocol (LISP) Control-Plane 10 draft-ietf-lisp-rfc6833bis-11 12 Abstract 14 This document describes the Control-Plane and Mapping Service for the 15 Locator/ID Separation Protocol (LISP), implemented by two new types 16 of LISP-speaking devices -- the LISP Map-Resolver and LISP Map-Server 17 -- that provides a simplified "front end" for one or more Endpoint ID 18 to Routing Locator mapping databases. 20 By using this Control-Plane service interface and communicating with 21 Map-Resolvers and Map-Servers, LISP Ingress Tunnel Routers (ITRs) and 22 Egress Tunnel Routers (ETRs) are not dependent on the details of 23 mapping database systems, which facilitates modularity with different 24 database designs. Since these devices implement the "edge" of the 25 LISP Control-Plane infrastructure, connect directly to LISP-capable 26 Internet end sites, and comprising the bulk of LISP-speaking devices, 27 reducing their implementation and operational complexity should also 28 reduce the overall cost and effort of deploying LISP. 30 This document obsoletes RFC 6833. 32 Status of This Memo 34 This Internet-Draft is submitted in full conformance with the 35 provisions of BCP 78 and BCP 79. 37 Internet-Drafts are working documents of the Internet Engineering 38 Task Force (IETF). Note that other groups may also distribute 39 working documents as Internet-Drafts. The list of current Internet- 40 Drafts is at https://datatracker.ietf.org/drafts/current/. 42 Internet-Drafts are draft documents valid for a maximum of six months 43 and may be updated, replaced, or obsoleted by other documents at any 44 time. It is inappropriate to use Internet-Drafts as reference 45 material or to cite them other than as "work in progress." 47 This Internet-Draft will expire on January 18, 2019. 49 Copyright Notice 51 Copyright (c) 2018 IETF Trust and the persons identified as the 52 document authors. All rights reserved. 54 This document is subject to BCP 78 and the IETF Trust's Legal 55 Provisions Relating to IETF Documents 56 (https://trustee.ietf.org/license-info) in effect on the date of 57 publication of this document. Please review these documents 58 carefully, as they describe your rights and restrictions with respect 59 to this document. Code Components extracted from this document must 60 include Simplified BSD License text as described in Section 4.e of 61 the Trust Legal Provisions and are provided without warranty as 62 described in the Simplified BSD License. 64 Table of Contents 66 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 67 2. Requirements Notation . . . . . . . . . . . . . . . . . . . . 4 68 3. Definition of Terms . . . . . . . . . . . . . . . . . . . . . 4 69 4. Basic Overview . . . . . . . . . . . . . . . . . . . . . . . 5 70 5. LISP IPv4 and IPv6 Control-Plane Packet Formats . . . . . . . 7 71 5.1. LISP Control Packet Type Allocations . . . . . . . . . . 9 72 5.2. Map-Request Message Format . . . . . . . . . . . . . . . 10 73 5.3. EID-to-RLOC UDP Map-Request Message . . . . . . . . . . . 13 74 5.4. Map-Reply Message Format . . . . . . . . . . . . . . . . 15 75 5.5. EID-to-RLOC UDP Map-Reply Message . . . . . . . . . . . . 19 76 5.6. Map-Register Message Format . . . . . . . . . . . . . . . 22 77 5.7. Map-Notify/Map-Notify-Ack Message Format . . . . . . . . 25 78 5.8. Encapsulated Control Message Format . . . . . . . . . . . 26 79 6. Changing the Contents of EID-to-RLOC Mappings . . . . . . . . 28 80 6.1. Solicit-Map-Request (SMR) . . . . . . . . . . . . . . . . 28 81 7. Routing Locator Reachability . . . . . . . . . . . . . . . . 29 82 7.1. RLOC-Probing Algorithm . . . . . . . . . . . . . . . . . 31 83 8. Interactions with Other LISP Components . . . . . . . . . . . 32 84 8.1. ITR EID-to-RLOC Mapping Resolution . . . . . . . . . . . 32 85 8.2. EID-Prefix Configuration and ETR Registration . . . . . . 33 86 8.3. Map-Server Processing . . . . . . . . . . . . . . . . . . 35 87 8.4. Map-Resolver Processing . . . . . . . . . . . . . . . . . 36 88 8.4.1. Anycast Map-Resolver Operation . . . . . . . . . . . 36 89 9. Security Considerations . . . . . . . . . . . . . . . . . . . 36 90 10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 37 91 10.1. LISP UDP Port Numbers . . . . . . . . . . . . . . . . . 38 92 10.2. LISP Packet Type Codes . . . . . . . . . . . . . . . . . 38 93 10.3. LISP ACT and Flag Fields . . . . . . . . . . . . . . . . 38 94 10.4. LISP Address Type Codes . . . . . . . . . . . . . . . . 39 95 10.5. LISP Algorithm ID Numbers . . . . . . . . . . . . . . . 39 96 11. References . . . . . . . . . . . . . . . . . . . . . . . . . 39 97 11.1. Normative References . . . . . . . . . . . . . . . . . . 39 98 11.2. Informative References . . . . . . . . . . . . . . . . . 40 99 Appendix A. Acknowledgments . . . . . . . . . . . . . . . . . . 44 100 Appendix B. Document Change Log . . . . . . . . . . . . . . . . 44 101 B.1. Changes to draft-ietf-lisp-rfc6833bis-11 . . . . . . . . 44 102 B.2. Changes to draft-ietf-lisp-rfc6833bis-10 . . . . . . . . 44 103 B.3. Changes to draft-ietf-lisp-rfc6833bis-09 . . . . . . . . 44 104 B.4. Changes to draft-ietf-lisp-rfc6833bis-08 . . . . . . . . 44 105 B.5. Changes to draft-ietf-lisp-rfc6833bis-07 . . . . . . . . 45 106 B.6. Changes to draft-ietf-lisp-rfc6833bis-06 . . . . . . . . 45 107 B.7. Changes to draft-ietf-lisp-rfc6833bis-05 . . . . . . . . 45 108 B.8. Changes to draft-ietf-lisp-rfc6833bis-04 . . . . . . . . 46 109 B.9. Changes to draft-ietf-lisp-rfc6833bis-03 . . . . . . . . 46 110 B.10. Changes to draft-ietf-lisp-rfc6833bis-02 . . . . . . . . 46 111 B.11. Changes to draft-ietf-lisp-rfc6833bis-01 . . . . . . . . 46 112 B.12. Changes to draft-ietf-lisp-rfc6833bis-00 . . . . . . . . 47 113 B.13. Changes to draft-farinacci-lisp-rfc6833bis-00 . . . . . . 47 114 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 48 116 1. Introduction 118 The Locator/ID Separation Protocol [I-D.ietf-lisp-introduction] and 119 [I-D.ietf-lisp-rfc6830bis] specifies an architecture and mechanism 120 for dynamic tunnelling by logically separating the addresses 121 currently used by IP in two separate name spaces: Endpoint IDs 122 (EIDs), used within sites; and Routing Locators (RLOCs), used on the 123 transit networks that make up the Internet infrastructure. To 124 achieve this separation, LISP defines protocol mechanisms for mapping 125 from EIDs to RLOCs. In addition, LISP assumes the existence of a 126 database to store and propagate those mappings globally. Several 127 such databases have been proposed; among them are the Content 128 distribution Overlay Network Service for LISP-NERD (a Not-so-novel 129 EID-to-RLOC Database) [RFC6837], LISP Alternative Logical Topology 130 (LISP-ALT) [RFC6836], and LISP Delegated Database Tree (LISP-DDT) 131 [RFC8111]. 133 The LISP Mapping Service defines two new types of LISP-speaking 134 devices: the Map-Resolver, which accepts Map-Requests from an Ingress 135 Tunnel Router (ITR) and "resolves" the EID-to-RLOC mapping using a 136 mapping database; and the Map-Server, which learns authoritative EID- 137 to-RLOC mappings from an Egress Tunnel Router (ETR) and publishes 138 them in a database. 140 This LISP Control-Plane Mapping Service can be used by many different 141 encapsulation-based or translation-based Data-Planes which include 142 but are not limited to the ones defined in LISP RFC 6830bis 143 [I-D.ietf-lisp-rfc6830bis], LISP-GPE [I-D.lewis-lisp-gpe], VXLAN 145 [RFC7348], VXLAN-GPE [I-D.quinn-vxlan-gpe], and ILA 146 [I-D.herbert-intarea-ila]. 148 Conceptually, LISP Map-Servers share some of the same basic 149 configuration and maintenance properties as Domain Name System (DNS) 150 [RFC1035] servers; likewise, Map-Resolvers are conceptually similar 151 to DNS caching resolvers. With this in mind, this specification 152 borrows familiar terminology (resolver and server) from the DNS 153 specifications. 155 Note that while this document assumes a LISP-ALT database mapping 156 infrastructure to illustrate certain aspects of Map-Server and Map- 157 Resolver operation, the Mapping Service interface can (and likely 158 will) be used by ITRs and ETRs to access other mapping database 159 systems as the LISP infrastructure evolves. 161 The LISP Mapping Service is an important component of the LISP 162 toolset. Issues and concerns about the deployment of LISP for 163 Internet traffic are discussed in [I-D.ietf-lisp-rfc6830bis], 164 [RFC7215], and [I-D.rodrigueznatal-lisp-oam]. 166 This document obsoletes RFC 6833. 168 2. Requirements Notation 170 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 171 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 172 document are to be interpreted as described in [RFC2119]. 174 3. Definition of Terms 176 Map-Server: A network infrastructure component that learns of EID- 177 Prefix mapping entries from an ETR, via the registration mechanism 178 described below, or some other authoritative source if one exists. 179 A Map-Server publishes these EID-Prefixes in a mapping database. 181 Map-Request: A LISP Map-Request is a Control-Plane message to query 182 the mapping system to resolve an EID. A LISP Map-Request can also 183 be sent to an RLOC to test for reachability and to exchange 184 security keys between an encapsulator and a decapsulator. This 185 type of Map-Request is also known as an RLOC-Probe Request. 187 Map-Reply: A LISP Map-Reply is a Control-Plane message returned in 188 response to a Map-Request sent to the mapping system when 189 resolving an EID. A LISP Map-Reply can also be returned by a 190 decapsulator in response to a Map-Request sent by an encapsulator 191 to test for reachability. This type of Map-Reply is known as a 192 RLOC-Probe Reply. 194 Encapsulated Map-Request: A LISP Map-Request carried within an 195 Encapsulated Control Message (ECM), which has an additional LISP 196 header prepended. Sent to UDP destination port 4342. The "outer" 197 addresses are routable IP addresses, also known as RLOCs. Used by 198 an ITR when sending to a Map-Resolver and by a Map-Server when 199 forwarding a Map-Request to an ETR. 201 Map-Resolver: A network infrastructure component that accepts LISP 202 Encapsulated (ECM) Map-Requests, typically from an ITR, and 203 determines whether or not the destination IP address is part of 204 the EID namespace; if it is not, a Negative Map-Reply is returned. 205 Otherwise, the Map-Resolver finds the appropriate EID-to-RLOC 206 mapping by consulting a mapping database system. 208 Negative Map-Reply: A LISP Map-Reply that contains an empty 209 Locator-Set. Returned in response to a Map-Request if the 210 destination EID is not registered in the mapping system, is policy 211 denied or fails authentication. 213 Map-Register message: A LISP message sent by an ETR to a Map-Server 214 to register its associated EID-Prefixes. In addition to the set 215 of EID-Prefixes to register, the message includes one or more 216 RLOCs to reach ETR(s). The Map-Server uses these RLOCs when 217 forwarding Map-Requests (re-formatted as Encapsulated Map- 218 Requests). An ETR MAY request that the Map-Server answer Map- 219 Requests on its behalf by setting the "proxy Map-Reply" flag 220 (P-bit) in the message. 222 Map-Notify message: A LISP message sent by a Map-Server to an ETR 223 to confirm that a Map-Register has been received and processed. 224 An ETR requests that a Map-Notify be returned by setting the 225 "want-map-notify" flag (M-bit) in the Map-Register message. 226 Unlike a Map-Reply, a Map-Notify uses UDP port 4342 for both 227 source and destination. Map-Notify messages are also sent to ITRs 228 by Map-Servers when there are RLOC-set changes. 230 For definitions of other terms, notably Ingress Tunnel Router (ITR), 231 Egress Tunnel Router (ETR), and Re-encapsulating Tunnel Router (RTR), 232 refer to the LISP Data-Plane specification 233 [I-D.ietf-lisp-rfc6830bis]. 235 4. Basic Overview 237 A Map-Server is a device that publishes EID-Prefixes in a LISP 238 mapping database on behalf of a set of ETRs. When it receives a Map 239 Request (typically from an ITR), it consults the mapping database to 240 find an ETR that can answer with the set of RLOCs for an EID-Prefix. 241 To publish its EID-Prefixes, an ETR periodically sends Map-Register 242 messages to the Map-Server. A Map-Register message contains a list 243 of EID-Prefixes plus a set of RLOCs that can be used to reach the 244 ETRs. 246 When LISP-ALT [RFC6836] is used as the mapping database, a Map-Server 247 connects to the ALT network and acts as a "last-hop" ALT-Router. 248 Intermediate ALT-Routers forward Map-Requests to the Map-Server that 249 advertises a particular EID-Prefix, and the Map-Server forwards them 250 to the owning ETR, which responds with Map-Reply messages. 252 When LISP-DDT [RFC8111] is used as the mapping database, a Map-Server 253 sends the final Map-Referral messages from the Delegated Database 254 Tree. 256 A Map-Resolver receives Encapsulated Map-Requests from its client 257 ITRs and uses a mapping database system to find the appropriate ETR 258 to answer those requests. On a LISP-ALT network, a Map-Resolver acts 259 as a "first-hop" ALT-Router. It has Generic Routing Encapsulation 260 (GRE) tunnels configured to other ALT-Routers and uses BGP to learn 261 paths to ETRs for different prefixes in the LISP-ALT database. The 262 Map-Resolver uses this path information to forward Map-Requests over 263 the ALT to the correct ETRs. On a LISP-DDT network [RFC8111], a Map- 264 Resolver maintains a referral-cache and acts as a "first-hop" DDT- 265 node. The Map-Resolver uses the referral information to forward Map- 266 Requests. 268 Note that while it is conceivable that a Map-Resolver could cache 269 responses to improve performance, issues surrounding cache management 270 will need to be resolved so that doing so will be reliable and 271 practical. As initially deployed, Map-Resolvers will operate only in 272 a non-caching mode, decapsulating and forwarding Encapsulated Map 273 Requests received from ITRs. Any specification of caching 274 functionality is out of scope for this document. 276 Note that a single device can implement the functions of both a Map- 277 Server and a Map-Resolver, and in many cases the functions will be 278 co-located in that way. Also, there can be ALT-only nodes and DDT- 279 only nodes, when LISP-ALT and LISP-DDT are used, respectively, to 280 connecting Map-Resolvers and Map-Servers together to make up the 281 Mapping System. 283 5. LISP IPv4 and IPv6 Control-Plane Packet Formats 285 The following UDP packet formats are used by the LISP control plane. 287 0 1 2 3 288 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 289 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 290 |Version| IHL |Type of Service| Total Length | 291 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 292 | Identification |Flags| Fragment Offset | 293 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 294 | Time to Live | Protocol = 17 | Header Checksum | 295 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 296 | Source Routing Locator | 297 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 298 | Destination Routing Locator | 299 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 300 / | Source Port | Dest Port | 301 UDP +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 302 \ | UDP Length | UDP Checksum | 303 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 304 | | 305 | LISP Message | 306 | | 307 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 309 0 1 2 3 310 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 311 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 312 |Version| Traffic Class | Flow Label | 313 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 314 | Payload Length | Next Header=17| Hop Limit | 315 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 316 | | 317 + + 318 | | 319 + Source Routing Locator + 320 | | 321 + + 322 | | 323 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 324 | | 325 + + 326 | | 327 + Destination Routing Locator + 328 | | 329 + + 330 | | 331 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 332 / | Source Port | Dest Port | 333 UDP +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 334 \ | UDP Length | UDP Checksum | 335 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 336 | | 337 | LISP Message | 338 | | 339 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 341 When a UDP Map-Request, Map-Register, or Map-Notify (when used as a 342 notification message) are sent, the UDP source port is chosen by the 343 sender and the destination UDP port number is set to 4342. When a 344 UDP Map-Reply Map-Notify (when used as an acknowledgement to a Map- 345 Register), or Map-Notify-Ack are sent, the source UDP port number is 346 set to 4342 and the destination UDP port number is copied from the 347 source port of either the Map-Request or the invoking data packet. 348 Implementations MUST be prepared to accept packets when either the 349 source port or destination UDP port is set to 4342 due to NATs 350 changing port number values. 352 The 'UDP Length' field will reflect the length of the UDP header and 353 the LISP Message payload. 355 The UDP checksum is computed and set to non-zero for all messages 356 sent to or from port 4342. It MUST be checked on receipt, and if the 357 checksum fails, the control message MUST be dropped [RFC1071]. 359 The format of control messages includes the UDP header so the 360 checksum and length fields can be used to protect and delimit message 361 boundaries. 363 5.1. LISP Control Packet Type Allocations 365 This section defines the LISP control message formats and summarizes 366 for IANA the LISP Type codes assigned by this document. For 367 completeness, this document references the LISP Shared Extension 368 Message assigned by [RFC8113]. Message type definitions are: 370 Reserved: 0 b'0000' 371 LISP Map-Request: 1 b'0001' 372 LISP Map-Reply: 2 b'0010' 373 LISP Map-Register: 3 b'0011' 374 LISP Map-Notify: 4 b'0100' 375 LISP Map-Notify-Ack: 5 b'0101' 376 LISP Map-Referral: 6 b'0110' 377 LISP Encapsulated Control Message: 8 b'1000' 378 Not Assigned 9-14 b'1001'- b'1110' 379 LISP Shared Extension Message: 15 b'1111' [RFC8113] 381 Values in the "Not Assigned" range can be assigned according to 382 procedures in [RFC8126]. Documents that request for a new LISP 383 packet type MAY indicate a preferred value. 385 Protocol designers experimenting with new message formats SHOULD use 386 the LISP Shared Extension Message Type and request a [RFC8113] sub- 387 type assignment. 389 All LISP Control-Plane messages use Address Family Identifiers (AFI) 390 [AFI] or LISP Canonical Address Format (LCAF) [RFC8060] formats to 391 encode either fixed or variable length addresses. This includes 392 explicit fields in each control message or part of EID-records or 393 RLOC-records in commonly formatted messages. 395 The LISP control-plane describes how other data-planes can encode 396 messages to support the SMR and RLOC-probing procedures. 398 5.2. Map-Request Message Format 400 0 1 2 3 401 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 402 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 403 |Type=1 |A|M|P|S|p|s|m|I| Rsvd |L|D| IRC | Record Count | 404 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 405 | Nonce . . . | 406 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 407 | . . . Nonce | 408 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 409 | Source-EID-AFI | Source EID Address ... | 410 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 411 | ITR-RLOC-AFI 1 | ITR-RLOC Address 1 ... | 412 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 413 | ... | 414 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 415 | ITR-RLOC-AFI n | ITR-RLOC Address n ... | 416 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 417 / | Reserved | EID mask-len | EID-Prefix-AFI | 418 Rec +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 419 \ | EID-Prefix ... | 420 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 421 | Map-Reply Record ... | 422 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 424 Packet field descriptions: 426 Type: 1 (Map-Request) 428 A: This is an authoritative bit, which is set to 0 for UDP-based Map- 429 Requests sent by an ITR. It is set to 1 when an ITR wants the 430 destination site to return the Map-Reply rather than the mapping 431 database system. 433 M: This is the map-data-present bit. When set, it indicates that a 434 Map-Reply Record segment is included in the Map-Request. 436 P: This is the probe-bit, which indicates that a Map-Request SHOULD 437 be treated as a Locator reachability probe. The receiver SHOULD 438 respond with a Map-Reply with the probe-bit set, indicating that 439 the Map-Reply is a Locator reachability probe reply, with the 440 nonce copied from the Map-Request. See RLOC-Probing Section 7.1 441 for more details. 443 S: This is the Solicit-Map-Request (SMR) bit. See Solicit-Map- 444 Request (SMRs) Section 6.1 for details. 446 p: This is the PITR bit. This bit is set to 1 when a PITR sends a 447 Map-Request. 449 s: This is the SMR-invoked bit. This bit is set to 1 when an xTR is 450 sending a Map-Request in response to a received SMR-based Map- 451 Request. 453 m: This is the LISP mobile-node m-bit. This bit is set by xTRs that 454 operate as a mobile node as defined in [I-D.ietf-lisp-mn]. 456 I: This is the xTR-ID bit. When this bit is set, what is appended to 457 the Map-Request is a 128-bit xTR router-ID. See LISP PubSub usage 458 procedures in [I-D.rodrigueznatal-lisp-pubsub] for details. 460 Rsvd: This field MUST be set to 0 on transmit and MUST be ignored on 461 receipt. 463 L: This is the local-xtr bit. It is used by an xTR in a LISP site to 464 tell other xTRs in the same site that it is part of the RLOC-set 465 for the LISP site. The L-bit is set to 1 when the RLOC is the 466 sender's IP address. 468 D: This is the dont-map-reply bit. It is used in the SMR procedure 469 described in Section 6.1. When an xTR sends an SMR Map-Request 470 message, it doesn't need a Map-Reply returned. When this bit is 471 set, the receiver of the Map-Request does not return a Map-Reply. 473 IRC: This 5-bit field is the ITR-RLOC Count, which encodes the 474 additional number of ('ITR-RLOC-AFI', 'ITR-RLOC Address') fields 475 present in this message. At least one (ITR-RLOC-AFI, ITR-RLOC- 476 Address) pair MUST be encoded. Multiple 'ITR-RLOC Address' fields 477 are used, so a Map-Replier can select which destination address to 478 use for a Map-Reply. The IRC value ranges from 0 to 31. For a 479 value of 0, there is 1 ITR-RLOC address encoded; for a value of 1, 480 there are 2 ITR-RLOC addresses encoded, and so on up to 31, which 481 encodes a total of 32 ITR-RLOC addresses. 483 Record Count: This is the number of records in this Map-Request 484 message. A record is comprised of the portion of the packet that 485 is labeled 'Rec' above and occurs the number of times equal to 486 Record Count. For this version of the protocol, a receiver MUST 487 accept and process Map-Requests that contain one or more records, 488 but a sender MUST only send Map-Requests containing one record. 489 Support for requesting multiple EIDs in a single Map-Request 490 message will be specified in a future version of the protocol. 492 Nonce: This is an 8-octet random value created by the sender of the 493 Map-Request. This nonce will be returned in the Map-Reply. The 494 security of the LISP mapping protocol critically depends on the 495 strength of the nonce in the Map-Request message. The nonce 496 SHOULD be generated by a properly seeded pseudo-random (or strong 497 random) source. See [RFC4086] for advice on generating security- 498 sensitive random data. 500 Source-EID-AFI: This is the address family of the 'Source EID 501 Address' field. 503 Source EID Address: This is the EID of the source host that 504 originated the packet that caused the Map-Request. When Map- 505 Requests are used for refreshing a Map-Cache entry or for RLOC- 506 Probing, an AFI value 0 is used and this field is of zero length. 508 ITR-RLOC-AFI: This is the address family of the 'ITR-RLOC Address' 509 field that follows this field. 511 ITR-RLOC Address: This is used to give the ETR the option of 512 selecting the destination address from any address family for the 513 Map-Reply message. This address MUST be a routable RLOC address 514 of the sender of the Map-Request message. 516 EID mask-len: This is the mask length for the EID-Prefix. 518 EID-Prefix-AFI: This is the address family of the EID-Prefix 519 according to [AFI] and [RFC8060]. 521 EID-Prefix: This prefix is 4 octets for an IPv4 address family and 522 16 octets for an IPv6 address family when the EID-Prefix-AFI is 1 523 or 2, respectively. For other AFIs [AFI], the length varies and 524 for the LCAF AFI the format is defined in [RFC8060]. When a Map- 525 Request is sent by an ITR because a data packet is received for a 526 destination where there is no mapping entry, the EID-Prefix is set 527 to the destination IP address of the data packet, and the 'EID 528 mask-len' is set to 32 or 128 for IPv4 or IPv6, respectively. 529 When an xTR wants to query a site about the status of a mapping it 530 already has cached, the EID-Prefix used in the Map-Request has the 531 same mask length as the EID-Prefix returned from the site when it 532 sent a Map-Reply message. 534 Map-Reply Record: When the M-bit is set, this field is the size of a 535 single "Record" in the Map-Reply format. This Map-Reply record 536 contains the EID-to-RLOC mapping entry associated with the Source 537 EID. This allows the ETR that will receive this Map-Request to 538 cache the data if it chooses to do so. 540 5.3. EID-to-RLOC UDP Map-Request Message 542 A Map-Request is sent from an ITR when it needs a mapping for an EID, 543 wants to test an RLOC for reachability, or wants to refresh a mapping 544 before TTL expiration. For the initial case, the destination IP 545 address used for the Map-Request is the data packet's destination 546 address (i.e., the destination EID) that had a mapping cache lookup 547 failure. For the latter two cases, the destination IP address used 548 for the Map-Request is one of the RLOC addresses from the Locator-Set 549 of the Map-Cache entry. The source address is either an IPv4 or IPv6 550 RLOC address, depending on whether the Map-Request is using an IPv4 551 or IPv6 header, respectively. In all cases, the UDP source port 552 number for the Map-Request message is a 16-bit value selected by the 553 ITR/PITR, and the UDP destination port number is set to the well- 554 known destination port number 4342. A successful Map-Reply, which is 555 one that has a nonce that matches an outstanding Map-Request nonce, 556 will update the cached set of RLOCs associated with the EID-Prefix 557 range. 559 One or more Map-Request ('ITR-RLOC-AFI', 'ITR-RLOC-Address') fields 560 MUST be filled in by the ITR. The number of fields (minus 1) encoded 561 MUST be placed in the 'IRC' field. The ITR MAY include all locally 562 configured Locators in this list or just provide one locator address 563 from each address family it supports. If the ITR erroneously 564 provides no ITR-RLOC addresses, the Map-Replier MUST drop the Map- 565 Request. 567 Map-Requests can also be LISP encapsulated using UDP destination 568 port 4342 with a LISP Type value set to "Encapsulated Control 569 Message", when sent from an ITR to a Map-Resolver. Likewise, Map- 570 Requests are LISP encapsulated the same way from a Map-Server to an 571 ETR. Details on Encapsulated Map-Requests and Map-Resolvers can be 572 found in Section 5.8. 574 Map-Requests MUST be rate-limited. It is RECOMMENDED that a Map- 575 Request for the same EID-Prefix be sent no more than once per second. 577 An ITR that is configured with mapping database information (i.e., it 578 is also an ETR) MAY optionally include those mappings in a Map- 579 Request. When an ETR configured to accept and verify such 580 "piggybacked" mapping data receives such a Map-Request and it does 581 not have this mapping in the Map-Cache, it MAY originate a "verifying 582 Map-Request", addressed to the map-requesting ITR and the ETR MAY add 583 a Map-Cache entry. If the ETR has a Map-Cache entry that matches the 584 "piggybacked" EID and the RLOC is in the Locator-Set for the entry, 585 then it MAY send the "verifying Map-Request" directly to the 586 originating Map-Request source. If the RLOC is not in the Locator- 587 Set, then the ETR MUST send the "verifying Map-Request" to the 588 "piggybacked" EID. Doing this forces the "verifying Map-Request" to 589 go through the mapping database system to reach the authoritative 590 source of information about that EID, guarding against RLOC-spoofing 591 in the "piggybacked" mapping data. 593 5.4. Map-Reply Message Format 595 0 1 2 3 596 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 597 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 598 |Type=2 |P|E|S| Reserved | Record Count | 599 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 600 | Nonce . . . | 601 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 602 | . . . Nonce | 603 +-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 604 | | Record TTL | 605 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 606 R | Locator Count | EID mask-len | ACT |A| Reserved | 607 e +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 608 c | Rsvd | Map-Version Number | EID-Prefix-AFI | 609 o +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 610 r | EID-Prefix | 611 d +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 612 | /| Priority | Weight | M Priority | M Weight | 613 | L +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 614 | o | Unused Flags |L|p|R| Loc-AFI | 615 | c +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 616 | \| Locator | 617 +-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 619 Packet field descriptions: 621 Type: 2 (Map-Reply) 623 P: This is the probe-bit, which indicates that the Map-Reply is in 624 response to a Locator reachability probe Map-Request. The 'Nonce' 625 field MUST contain a copy of the nonce value from the original 626 Map-Request. See RLOC-probing Section 7.1 for more details. When 627 the probe-bit is set to 1 in a Map-Reply message, the A-bit in 628 each EID-record included in the message MUST be set to 1. 630 E: This bit indicates that the ETR that sends this Map-Reply message 631 is advertising that the site is enabled for the Echo-Nonce Locator 632 reachability algorithm. See Echo-Nonce [I-D.ietf-lisp-rfc6830bis] 633 for more details. 635 S: This is the Security bit. When set to 1, the following 636 authentication information will be appended to the end of the Map- 637 Reply. The details of signing a Map-Reply message can be found in 638 [I-D.ietf-lisp-sec]. 640 0 1 2 3 641 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 642 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 643 | AD Type | Authentication Data Content . . . | 644 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 646 Reserved: This field MUST be set to 0 on transmit and MUST be 647 ignored on receipt. 649 Record Count: This is the number of records in this reply message. 650 A record is comprised of that portion of the packet labeled 651 'Record' above and occurs the number of times equal to Record 652 Count. 654 Nonce: This is a 24-bit value set in a Data-Probe 655 [I-D.ietf-lisp-rfc6830bis] or a 64-bit value from the Map-Request 656 is echoed in this 'Nonce' field of the Map-Reply. When a 24-bit 657 value is supplied, it resides in the low-order 64 bits of the 658 'Nonce' field. 660 Record TTL: This is the time in minutes the recipient of the Map- 661 Reply will store the mapping. If the TTL is 0, the entry MUST be 662 removed from the cache immediately. If the value is 0xffffffff, 663 the recipient can decide locally how long to store the mapping. 665 Locator Count: This is the number of Locator entries. A Locator 666 entry comprises what is labeled above as 'Loc'. The Locator count 667 can be 0, indicating that there are no Locators for the EID- 668 Prefix. 670 EID mask-len: This is the mask length for the EID-Prefix. 672 ACT: This 3-bit field describes Negative Map-Reply actions. In any 673 other message type, these bits are set to 0 and ignored on 674 receipt. These bits are used only when the 'Locator Count' field 675 is set to 0. The action bits are encoded only in Map-Reply 676 messages. They are used to tell an ITR or PITR why a empty 677 locator-set was returned from the mapping system and how it stores 678 the map-cache entry. 680 (0) No-Action: The Map-Cache is kept alive, and no packet 681 encapsulation occurs. 683 (1) Natively-Forward: The packet is not encapsulated or dropped 684 but natively forwarded. 686 (2) Send-Map-Request: The Map-Cache entry is created and flagged 687 that any packet matching this entry invokes sending a Map- 688 Request. 690 (3) Drop/No-Reason: A packet that matches this Map-Cache entry is 691 dropped. An ICMP Destination Unreachable message SHOULD be 692 sent. 694 (4) Drop/Policy-Denied: A packet that matches this Map-Cache 695 entry is dropped. The reason for the Drop action is that a 696 Map-Request for the target-EID is being policy denied by 697 either an xTR or the mapping system. 699 (5) Drop/Authentication-Failure: A packet that matches this Map- 700 Cache entry is dropped. The reason for the Drop action is 701 that a Map-Request for the target-EID fails an authentication 702 verification-check by either an xTR or the mapping system. 704 A: The Authoritative bit, when sent, is always set to 1 by an ETR. 705 When a Map-Server is proxy Map-Replying for a LISP site, the 706 Authoritative bit is set to 0. This indicates to requesting ITRs 707 that the Map-Reply was not originated by a LISP node managed at 708 the site that owns the EID-Prefix. 710 Map-Version Number: When this 12-bit value is non-zero, the Map- 711 Reply sender is informing the ITR what the version number is for 712 the EID record contained in the Map-Reply. The ETR can allocate 713 this number internally but MUST coordinate this value with other 714 ETRs for the site. When this value is 0, there is no versioning 715 information conveyed. The Map-Version Number can be included in 716 Map-Request and Map-Register messages. See Map-Versioning 717 [RFC6834] for more details. 719 EID-Prefix-AFI: Address family of the EID-Prefix according to [AFI] 720 and [RFC8060]. 722 EID-Prefix: This prefix is 4 octets for an IPv4 address family and 723 16 octets for an IPv6 address family. 725 Priority: Each RLOC is assigned a unicast Priority. Lower values 726 are more preferable. When multiple RLOCs have the same Priority, 727 they MAY be used in a load-split fashion. A value of 255 means 728 the RLOC MUST NOT be used for unicast forwarding. 730 Weight: When priorities are the same for multiple RLOCs, the Weight 731 indicates how to balance unicast traffic between them. Weight is 732 encoded as a relative weight of total unicast packets that match 733 the mapping entry. For example, if there are 4 Locators in a 734 Locator-Set, where the Weights assigned are 30, 20, 20, and 10, 735 the first Locator will get 37.5% of the traffic, the 2nd and 3rd 736 Locators will get 25% of the traffic, and the 4th Locator will get 737 12.5% of the traffic. If all Weights for a Locator-Set are equal, 738 the receiver of the Map-Reply will decide how to load-split the 739 traffic. See RLOC-hashing [I-D.ietf-lisp-rfc6830bis] for a 740 suggested hash algorithm to distribute the load across Locators 741 with the same Priority and equal Weight values. 743 M Priority: Each RLOC is assigned a multicast Priority used by an 744 ETR in a receiver multicast site to select an ITR in a source 745 multicast site for building multicast distribution trees. A value 746 of 255 means the RLOC MUST NOT be used for joining a multicast 747 distribution tree. For more details, see [RFC6831]. 749 M Weight: When priorities are the same for multiple RLOCs, the 750 Weight indicates how to balance building multicast distribution 751 trees across multiple ITRs. The Weight is encoded as a relative 752 weight (similar to the unicast Weights) of the total number of 753 trees built to the source site identified by the EID-Prefix. If 754 all Weights for a Locator-Set are equal, the receiver of the Map- 755 Reply will decide how to distribute multicast state across ITRs. 756 For more details, see [RFC6831]. 758 Unused Flags: These are set to 0 when sending and ignored on 759 receipt. 761 L: When this bit is set, the Locator is flagged as a local Locator to 762 the ETR that is sending the Map-Reply. When a Map-Server is doing 763 proxy Map-Replying for a LISP site, the L-bit is set to 0 for all 764 Locators in this Locator-Set. 766 p: When this bit is set, an ETR informs the RLOC-Probing ITR that the 767 locator address for which this bit is set is the one being RLOC- 768 probed and MAY be different from the source address of the Map- 769 Reply. An ITR that RLOC-probes a particular Locator MUST use this 770 Locator for retrieving the data structure used to store the fact 771 that the Locator is reachable. The p-bit is set for a single 772 Locator in the same Locator-Set. If an implementation sets more 773 than one p-bit erroneously, the receiver of the Map-Reply MUST 774 select the first Locator. The p-bit MUST NOT be set for Locator- 775 Set records sent in Map-Request and Map-Register messages. 777 R: This is set when the sender of a Map-Reply has a route to the 778 Locator in the Locator data record. This receiver MAY find this 779 useful to know if the Locator is up but not necessarily reachable 780 from the receiver's point of view. See also EID-Reachability 781 Section 7.1 for another way the R-bit MAY be used. 783 Locator: This is an IPv4 or IPv6 address (as encoded by the 'Loc- 784 AFI' field) assigned to an ETR. Note that the destination RLOC 785 address MAY be an anycast address. A source RLOC can be an 786 anycast address as well. The source or destination RLOC MUST NOT 787 be the broadcast address (255.255.255.255 or any subnet broadcast 788 address known to the router) and MUST NOT be a link-local 789 multicast address. The source RLOC MUST NOT be a multicast 790 address. The destination RLOC SHOULD be a multicast address if it 791 is being mapped from a multicast destination EID. 793 5.5. EID-to-RLOC UDP Map-Reply Message 795 A Map-Reply returns an EID-Prefix with a prefix length that is less 796 than or equal to the EID being requested. The EID being requested is 797 either from the destination field of an IP header of a Data-Probe or 798 the EID record of a Map-Request. The RLOCs in the Map-Reply are 799 routable IP addresses of all ETRs for the LISP site. Each RLOC 800 conveys status reachability but does not convey path reachability 801 from a requester's perspective. Separate testing of path 802 reachability is required. See RLOC-reachability Section 7.1 for 803 details. 805 Note that a Map-Reply MAY contain different EID-Prefix granularity 806 (prefix + length) than the Map-Request that triggers it. This might 807 occur if a Map-Request were for a prefix that had been returned by an 808 earlier Map-Reply. In such a case, the requester updates its cache 809 with the new prefix information and granularity. For example, a 810 requester with two cached EID-Prefixes that are covered by a Map- 811 Reply containing one less-specific prefix replaces the entry with the 812 less-specific EID-Prefix. Note that the reverse, replacement of one 813 less-specific prefix with multiple more-specific prefixes, can also 814 occur, not by removing the less-specific prefix but rather by adding 815 the more-specific prefixes that, during a lookup, will override the 816 less-specific prefix. 818 When an EID moves out of a LISP site [I-D.ietf-lisp-eid-mobility], 819 the database mapping system may have overlapping EID-prefixes. Or 820 when a LISP site is configured with multiple sets of ETRs that 821 support different EID-prefix lengths, the database mapping system may 822 have overlapping EID-prefixes. When overlapping EID-prefixes exist, 823 a Map-Request with an EID that best matches any EID-Prefix MUST be 824 returned in a single Map-Reply message. For instance, if an ETR had 825 database mapping entries for EID-Prefixes: 827 10.0.0.0/8 828 10.1.0.0/16 829 10.1.1.0/24 830 10.1.2.0/24 832 A Map-Request for EID 10.1.1.1 would cause a Map-Reply with a record 833 count of 1 to be returned with a mapping record EID-Prefix of 834 10.1.1.0/24. 836 A Map-Request for EID 10.1.5.5 would cause a Map-Reply with a record 837 count of 3 to be returned with mapping records for EID-Prefixes 838 10.1.0.0/16, 10.1.1.0/24, and 10.1.2.0/24. 840 Note that not all overlapping EID-Prefixes need to be returned but 841 only the more-specific entries (note that in the second example above 842 10.0.0.0/8 was not returned for requesting EID 10.1.5.5) for the 843 matching EID-Prefix of the requesting EID. When more than one EID- 844 Prefix is returned, all SHOULD use the same Time to Live value so 845 they can all time out at the same time. When a more-specific EID- 846 Prefix is received later, its Time to Live value in the Map-Reply 847 record can be stored even when other less-specific entries exist. 848 When a less-specific EID-Prefix is received later, its Map-Cache 849 expiration time SHOULD be set to the minimum expiration time of any 850 more-specific EID-Prefix in the Map-Cache. This is done so the 851 integrity of the EID-Prefix set is wholly maintained and so no more- 852 specific entries are removed from the Map-Cache while keeping less- 853 specific entries. 855 Map-Replies SHOULD be sent for an EID-Prefix no more often than once 856 per second to the same requesting router. For scalability, it is 857 expected that aggregation of EID addresses into EID-Prefixes will 858 allow one Map-Reply to satisfy a mapping for the EID addresses in the 859 prefix range, thereby reducing the number of Map-Request messages. 861 Map-Reply records can have an empty Locator-Set. A Negative Map- 862 Reply is a Map-Reply with an empty Locator-Set. Negative Map-Replies 863 convey special actions by the sender to the ITR or PITR that have 864 solicited the Map-Reply. There are two primary applications for 865 Negative Map-Replies. The first is for a Map-Resolver to instruct an 866 ITR or PITR when a destination is for a LISP site versus a non-LISP 867 site, and the other is to source quench Map-Requests that are sent 868 for non-allocated EIDs. 870 For each Map-Reply record, the list of Locators in a Locator-Set MUST 871 appear in the same order for each ETR that originates a Map-Reply 872 message. The Locator-Set MUST be sorted in order of ascending IP 873 address where an IPv4 locator address is considered numerically 'less 874 than' an IPv6 locator address. 876 When sending a Map-Reply message, the destination address is copied 877 from one of the 'ITR-RLOC' fields from the Map-Request. The ETR can 878 choose a locator address from one of the address families it 879 supports. For Data-Probes, the destination address of the Map-Reply 880 is copied from the source address of the Data-Probe message that is 881 invoking the reply. The source address of the Map-Reply is one of 882 the local IP addresses chosen to allow Unicast Reverse Path 883 Forwarding (uRPF) checks to succeed in the upstream service provider. 884 The destination port of a Map-Reply message is copied from the source 885 port of the Map-Request or Data-Probe, and the source port of the 886 Map-Reply message is set to the well-known UDP port 4342. 888 5.6. Map-Register Message Format 890 This section specifies the encoding format for the Map-Register 891 message. The message is sent in UDP with a destination UDP port of 892 4342 and a randomly selected UDP source port number. 894 The Map-Register message format is: 896 0 1 2 3 897 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 898 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 899 |Type=3 |P|S|I| Reserved |E|T|a|m|M| Record Count | 900 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 901 | Nonce . . . | 902 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 903 | . . . Nonce | 904 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 905 | Key ID | Algorithm ID | Authentication Data Length | 906 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 907 ~ Authentication Data ~ 908 +-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 909 | | Record TTL | 910 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 911 R | Locator Count | EID mask-len | ACT |A| Reserved | 912 e +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 913 c | Rsvd | Map-Version Number | EID-Prefix-AFI | 914 o +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 915 r | EID-Prefix | 916 d +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 917 | /| Priority | Weight | M Priority | M Weight | 918 | L +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 919 | o | Unused Flags |L|p|R| Loc-AFI | 920 | c +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 921 | \| Locator | 922 +-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 924 Packet field descriptions: 926 Type: 3 (Map-Register) 928 P: This is the proxy Map-Reply bit. When set to 1, an ETR sends a 929 Map-Register message requesting the Map-Server to proxy a Map- 930 Reply. The Map-Server will send non-authoritative Map-Replies on 931 behalf of the ETR. 933 S: This is the security-capable bit. When set, the procedures from 934 [I-D.ietf-lisp-sec] are supported. 936 I: This is the xTR-ID bit. When this bit is set, what is appended to 937 the Map-Register is a 128-bit xTR router-ID and then a 64-bit 938 site-ID. See LISP NAT-Traversal procedures in 939 [I-D.ermagan-lisp-nat-traversal] for details. 941 Reserved: This field MUST be set to 0 on transmit and MUST be 942 ignored on receipt. 944 E: This is the Map-Register EID-notify bit. This is used by a First- 945 Hop-Router (FHR) which discovers a dynamic-EID. This EID-notify 946 based Map-Register is sent by the FHR to the same site xTR that 947 propogates the Map-Register to the mapping system. The site xTR 948 keeps state to later Map-Notify the FHR after the EID has moves 949 away. See [I-D.ietf-lisp-eid-mobility] for a detailed use-case. 951 T: This is the use-TTL for timeout bit. When set to 1, the xTR wants 952 the Map-Server to time out registrations based on the value in the 953 "Record TTL" field of this message. 955 a: This is the merge-request bit. When set to 1, the xTR requests to 956 merge RLOC-records from different xTRs registering the same EID- 957 record. See signal-free multicast [RFC8378] for one use case 958 example. 960 m: This is the mobile-node bit. When set to 1, the registering xTR 961 supports the procedures in [I-D.ietf-lisp-mn]. 963 M: This is the want-map-notify bit. When set to 1, an ETR is 964 requesting a Map-Notify message to be returned in response to 965 sending a Map-Register message. The Map-Notify message sent by a 966 Map-Server is used to acknowledge receipt of a Map-Register 967 message. 969 Record Count: This is the number of records in this Map-Register 970 message. A record is comprised of that portion of the packet 971 labeled 'Record' above and occurs the number of times equal to 972 Record Count. 974 Nonce: This 8-octet 'Nonce' field is set to 0 in Map-Register 975 messages if no Map-Notify message is expected to acknowledge it. 976 Since the Map-Register message is authenticated, the 'Nonce' field 977 is not currently used for any security function but MAY be in the 978 future as part of an anti-replay solution. 980 Key ID: This is a configured key-id value that corresponds to a 981 shared-secret password that is used to authenticate the sender. 982 Multiple shared-secrets can be used to roll over keys in a non- 983 disruptive way. 985 Algorithm ID: This is the configured Message Authentication Code 986 (MAC) algorithm value used for the authentication function. See 987 Algorithm ID Numbers in the Section 10.5 for codepoint 988 assignments. 990 Authentication Data Length: This is the length in octets of the 991 'Authentication Data' field that follows this field. The length 992 of the 'Authentication Data' field is dependent on the MAC 993 algorithm used. The length field allows a device that doesn't 994 know the MAC algorithm to correctly parse the packet. 996 Authentication Data: This is the message digest used from the output 997 of the MAC algorithm. The entire Map-Register payload is 998 authenticated with this field preset to 0. After the MAC is 999 computed, it is placed in this field. Implementations of this 1000 specification MUST include support for HMAC-SHA-1-96 [RFC2404], 1001 and support for HMAC-SHA-256-128 [RFC4868] is RECOMMENDED. 1003 The definition of the rest of the Map-Register can be found in EID- 1004 record description in Section 5.4. 1006 5.7. Map-Notify/Map-Notify-Ack Message Format 1008 This section specifies the encoding format for the Map-Notify and 1009 Map-Notify-Ack messages. The messages are sent inside a UDP packet 1010 with source and destination UDP ports equal to 4342. 1012 The Map-Notify and Map-Notify-Ack message formats are: 1014 0 1 2 3 1015 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 1016 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1017 |Type=4/5| Reserved | Record Count | 1018 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1019 | Nonce . . . | 1020 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1021 | . . . Nonce | 1022 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1023 | Key ID | Algorithm ID | Authentication Data Length | 1024 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1025 ~ Authentication Data ~ 1026 +-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1027 | | Record TTL | 1028 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1029 R | Locator Count | EID mask-len | ACT |A| Reserved | 1030 e +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1031 c | Rsvd | Map-Version Number | EID-Prefix-AFI | 1032 o +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1033 r | EID-Prefix | 1034 d +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1035 | /| Priority | Weight | M Priority | M Weight | 1036 | L +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1037 | o | Unused Flags |L|p|R| Loc-AFI | 1038 | c +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1039 | \| Locator | 1040 +-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1042 Packet field descriptions: 1044 Type: 4/5 (Map-Notify/Map-Notify-Ack) 1046 The Map-Notify message has the same contents as a Map-Register 1047 message. See the Map-Register section for field descriptions. 1049 The Map-Notify-Ack message has the same contents as a Map-Notify 1050 message. It is used to acknowledge the receipt of a Map-Notify and 1051 for the sender to stop retransmitting a Map-Notify with the same 1052 nonce. 1054 5.8. Encapsulated Control Message Format 1056 An Encapsulated Control Message (ECM) is used to encapsulate control 1057 packets sent between xTRs and the mapping database system. 1059 0 1 2 3 1060 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 1061 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1062 / | IPv4 or IPv6 Header | 1063 OH | (uses RLOC addresses) | 1064 \ | | 1065 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1066 / | Source Port = xxxx | Dest Port = 4342 | 1067 UDP +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1068 \ | UDP Length | UDP Checksum | 1069 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1070 LISP |Type=8 |S|D|E|M| Reserved | 1071 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1072 / | IPv4 or IPv6 Header | 1073 IH | (uses RLOC or EID addresses) | 1074 \ | | 1075 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1076 / | Source Port = xxxx | Dest Port = yyyy | 1077 UDP +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1078 \ | UDP Length | UDP Checksum | 1079 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1080 LCM | LISP Control Message | 1081 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1083 Packet header descriptions: 1085 OH: The outer IPv4 or IPv6 header, which uses RLOC addresses in the 1086 source and destination header address fields. 1088 UDP: The outer UDP header with destination port 4342. The source 1089 port is randomly allocated. The checksum field MUST be non- 1090 zero. 1092 LISP: Type 8 is defined to be a "LISP Encapsulated Control Message", 1093 and what follows is either an IPv4 or IPv6 header as encoded by 1094 the first 4 bits after the 'Reserved' field. 1096 Type: 8 (Encapsulated Control Message (ECM)) 1098 S: This is the Security bit. When set to 1, the field following 1099 the 'Reserved' field will have the following Authentication 1100 Data format and follow the procedures from [I-D.ietf-lisp-sec]. 1102 0 1 2 3 1103 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 1104 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1105 | AD Type | Authentication Data Content . . . | 1106 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1108 D: This is the DDT-bit. When set to 1, the sender is requesting a 1109 Map-Referral message to be returned. The details of this 1110 procedure are described in [RFC8111]. 1112 E: This is the to-ETR bit. When set to 1, the Map-Server's 1113 intention is to forward the ECM to an authoritative ETR. 1115 M: This is the to-MS bit. When set to 1, a Map-Request is being 1116 sent to a co-located Map-Resolver and Map-Server where the 1117 message can be processed directly by the Map-Server versus the 1118 Map-Resolver using the LISP-DDT procedures in [RFC8111]. 1120 IH: The inner IPv4 or IPv6 header, which can use either RLOC or EID 1121 addresses in the header address fields. When a Map-Request is 1122 encapsulated in this packet format, the destination address in 1123 this header is an EID. 1125 UDP: The inner UDP header, where the port assignments depend on the 1126 control packet being encapsulated. When the control packet is 1127 a Map-Request or Map-Register, the source port is selected by 1128 the ITR/PITR and the destination port is 4342. When the 1129 control packet is a Map-Reply, the source port is 4342 and the 1130 destination port is assigned from the source port of the 1131 invoking Map-Request. Port number 4341 MUST NOT be assigned to 1132 either port. The checksum field MUST be non-zero. 1134 LCM: The format is one of the control message formats described in 1135 this section. At this time, only Map-Request messages are 1136 allowed to be Control-Plane (ECM) encapsulated. In the future, 1137 PIM Join/Prune messages [RFC6831] might be allowed. 1138 Encapsulating other types of LISP control messages is for 1139 further study. When Map-Requests are sent for RLOC-Probing 1140 purposes (i.e., the probe-bit is set), they MUST NOT be sent 1141 inside Encapsulated Control Messages. 1143 6. Changing the Contents of EID-to-RLOC Mappings 1145 In the LISP architecture ITRs/PITRs use a local Map-Cache to store 1146 EID-to-RLOC mappings for forwarding. When an ETR updates a mapping a 1147 mechanism is required to inform ITRs/PITRs that are using such 1148 mappings. 1150 The LISP Data-Plane defines several mechanism to update mappings 1151 [I-D.ietf-lisp-rfc6830bis]. This document specifies the Solicit-Map 1152 Request (SMR), a Control-Plane push-based mechanism. An additional 1153 Control-Plane mechanism based on the Publish/subscribe paradigm is 1154 specified in [I-D.rodrigueznatal-lisp-pubsub]. 1156 6.1. Solicit-Map-Request (SMR) 1158 Soliciting a Map-Request is a selective way for ETRs, at the site 1159 where mappings change, to control the rate they receive requests for 1160 Map-Reply messages. SMRs are also used to tell remote ITRs to update 1161 the mappings they have cached. 1163 Since the ETRs don't keep track of remote ITRs that have cached their 1164 mappings, they do not know which ITRs need to have their mappings 1165 updated. As a result, an ETR will solicit Map-Requests (called an 1166 SMR message) from those sites to which it has been sending 1167 encapsulated data for the last minute. In particular, an ETR will 1168 send an SMR to an ITR to which it has recently sent encapsulated 1169 data. This can only occur when both ITR and ETR functionality reside 1170 in the same router. 1172 An SMR message is simply a bit set in a Map-Request message. An ITR 1173 or PITR will send a Map-Request when they receive an SMR message. 1174 Both the SMR sender and the Map-Request responder MUST rate-limit 1175 these messages. Rate-limiting can be implemented as a global rate- 1176 limiter or one rate-limiter per SMR destination. 1178 The following procedure shows how an SMR exchange occurs when a site 1179 is doing Locator-Set compaction for an EID-to-RLOC mapping: 1181 1. When the database mappings in an ETR change, the ETRs at the site 1182 begin to send Map-Requests with the SMR bit set for each Locator 1183 in each Map-Cache entry the ETR caches. 1185 2. A remote ITR that receives the SMR message will schedule sending 1186 a Map-Request message to the source locator address of the SMR 1187 message or to the mapping database system. A newly allocated 1188 random nonce is selected, and the EID-Prefix used is the one 1189 copied from the SMR message. If the source Locator is the only 1190 Locator in the cached Locator-Set, the remote ITR SHOULD send a 1191 Map-Request to the database mapping system just in case the 1192 single Locator has changed and may no longer be reachable to 1193 accept the Map-Request. 1195 3. The remote ITR MUST rate-limit the Map-Request until it gets a 1196 Map-Reply while continuing to use the cached mapping. When 1197 Map-Versioning as described in [RFC6834] is used, an SMR sender 1198 can detect if an ITR is using the most up-to-date database 1199 mapping. 1201 4. The ETRs at the site with the changed mapping will reply to the 1202 Map-Request with a Map-Reply message that has a nonce from the 1203 SMR-invoked Map-Request. The Map-Reply messages SHOULD be rate- 1204 limited. This is important to avoid Map-Reply implosion. 1206 5. The ETRs at the site with the changed mapping record the fact 1207 that the site that sent the Map-Request has received the new 1208 mapping data in the Map-Cache entry for the remote site so the 1209 Locator-Status-Bits are reflective of the new mapping for packets 1210 going to the remote site. The ETR then stops sending SMR 1211 messages. 1213 For security reasons, an ITR MUST NOT process unsolicited Map- 1214 Replies. To avoid Map-Cache entry corruption by a third party, a 1215 sender of an SMR-based Map-Request MUST be verified. If an ITR 1216 receives an SMR-based Map-Request and the source is not in the 1217 Locator-Set for the stored Map-Cache entry, then the responding Map- 1218 Request MUST be sent with an EID destination to the mapping database 1219 system. Since the mapping database system is a more secure way to 1220 reach an authoritative ETR, it will deliver the Map-Request to the 1221 authoritative source of the mapping data. 1223 When an ITR receives an SMR-based Map-Request for which it does not 1224 have a cached mapping for the EID in the SMR message, it may not send 1225 an SMR-invoked Map-Request. This scenario can occur when an ETR 1226 sends SMR messages to all Locators in the Locator-Set it has stored 1227 in its Map-Cache but the remote ITRs that receive the SMR may not be 1228 sending packets to the site. There is no point in updating the ITRs 1229 until they need to send, in which case they will send Map-Requests to 1230 obtain a Map-Cache entry. 1232 7. Routing Locator Reachability 1234 This document defines several Control-Plane mechanisms for 1235 determining RLOC reachability. Please note that additional Data- 1236 Plane reachability mechanisms are defined in 1237 [I-D.ietf-lisp-rfc6830bis]. 1239 1. An ITR MAY receive an ICMP Network Unreachable or Host 1240 Unreachable message for an RLOC it is using. This indicates that 1241 the RLOC is likely down. Note that trusting ICMP messages may 1242 not be desirable, but neither is ignoring them completely. 1243 Implementations are encouraged to follow current best practices 1244 in treating these conditions [I-D.ietf-opsec-icmp-filtering]. 1246 2. When an ITR participates in the routing protocol that operates in 1247 the underlay routing system, it can determine that an RLOC is 1248 down when no Routing Information Base (RIB) entry exists that 1249 matches the RLOC IP address. 1251 3. An ITR MAY receive an ICMP Port Unreachable message from a 1252 destination host. This occurs if an ITR attempts to use 1253 interworking [RFC6832] and LISP-encapsulated data is sent to a 1254 non-LISP-capable site. 1256 4. An ITR MAY receive a Map-Reply from an ETR in response to a 1257 previously sent Map-Request. The RLOC source of the Map-Reply is 1258 likely up, since the ETR was able to send the Map-Reply to the 1259 ITR. 1261 5. An ITR/ETR pair can use the 'RLOC-Probing' mechanism described 1262 below. 1264 When ITRs receive ICMP Network Unreachable or Host Unreachable 1265 messages as a method to determine unreachability, they will refrain 1266 from using Locators that are described in Locator lists of Map- 1267 Replies. However, using this approach is unreliable because many 1268 network operators turn off generation of ICMP Destination Unreachable 1269 messages. 1271 If an ITR does receive an ICMP Network Unreachable or Host 1272 Unreachable message, it MAY originate its own ICMP Destination 1273 Unreachable message destined for the host that originated the data 1274 packet the ITR encapsulated. 1276 Also, BGP-enabled ITRs can unilaterally examine the RIB to see if a 1277 locator address from a Locator-Set in a mapping entry matches a 1278 prefix. If it does not find one and BGP is running in the Default- 1279 Free Zone (DFZ), it can decide to not use the Locator even though the 1280 Locator-Status-Bits indicate that the Locator is up. In this case, 1281 the path from the ITR to the ETR that is assigned the Locator is not 1282 available. More details are in [I-D.meyer-loc-id-implications]. 1284 Optionally, an ITR can send a Map-Request to a Locator, and if a Map- 1285 Reply is returned, reachability of the Locator has been determined. 1286 Obviously, sending such probes increases the number of control 1287 messages originated by Tunnel Routers for active flows, so Locators 1288 are assumed to be reachable when they are advertised. 1290 This assumption does create a dependency: Locator unreachability is 1291 detected by the receipt of ICMP Host Unreachable messages. When a 1292 Locator has been determined to be unreachable, it is not used for 1293 active traffic; this is the same as if it were listed in a Map-Reply 1294 with Priority 255. 1296 The ITR can test the reachability of the unreachable Locator by 1297 sending periodic Requests. Both Requests and Replies MUST be rate- 1298 limited. Locator reachability testing is never done with data 1299 packets, since that increases the risk of packet loss for end-to-end 1300 sessions. 1302 7.1. RLOC-Probing Algorithm 1304 RLOC-Probing is a method that an ITR or PITR can use to determine the 1305 reachability status of one or more Locators that it has cached in a 1306 Map-Cache entry. The probe-bit of the Map-Request and Map-Reply 1307 messages is used for RLOC-Probing. 1309 RLOC-Probing is done in the control plane on a timer basis, where an 1310 ITR or PITR will originate a Map-Request destined to a locator 1311 address from one of its own locator addresses. A Map-Request used as 1312 an RLOC-probe is NOT encapsulated and NOT sent to a Map-Server or to 1313 the mapping database system as one would when soliciting mapping 1314 data. The EID record encoded in the Map-Request is the EID-Prefix of 1315 the Map-Cache entry cached by the ITR or PITR. The ITR MAY include a 1316 mapping data record for its own database mapping information that 1317 contains the local EID-Prefixes and RLOCs for its site. RLOC-probes 1318 are sent periodically using a jittered timer interval. 1320 When an ETR receives a Map-Request message with the probe-bit set, it 1321 returns a Map-Reply with the probe-bit set. The source address of 1322 the Map-Reply is set according to the procedure described in 1323 [I-D.ietf-lisp-rfc6830bis]. The Map-Reply SHOULD contain mapping 1324 data for the EID-Prefix contained in the Map-Request. This provides 1325 the opportunity for the ITR or PITR that sent the RLOC-probe to get 1326 mapping updates if there were changes to the ETR's database mapping 1327 entries. 1329 There are advantages and disadvantages of RLOC-Probing. The greatest 1330 benefit of RLOC-Probing is that it can handle many failure scenarios 1331 allowing the ITR to determine when the path to a specific Locator is 1332 reachable or has become unreachable, thus providing a robust 1333 mechanism for switching to using another Locator from the cached 1334 Locator. RLOC-Probing can also provide rough Round-Trip Time (RTT) 1335 estimates between a pair of Locators, which can be useful for network 1336 management purposes as well as for selecting low delay paths. The 1337 major disadvantage of RLOC-Probing is in the number of control 1338 messages required and the amount of bandwidth used to obtain those 1339 benefits, especially if the requirement for failure detection times 1340 is very small. 1342 8. Interactions with Other LISP Components 1344 8.1. ITR EID-to-RLOC Mapping Resolution 1346 An ITR is configured with one or more Map-Resolver addresses. These 1347 addresses are "Locators" (or RLOCs) and MUST be routable on the 1348 underlying core network; they MUST NOT need to be resolved through 1349 LISP EID-to-RLOC mapping, as that would introduce a circular 1350 dependency. When using a Map-Resolver, an ITR does not need to 1351 connect to any other database mapping system. In particular, the ITR 1352 need not connect to the LISP-ALT infrastructure or implement the BGP 1353 and GRE protocols that it uses. 1355 An ITR sends an Encapsulated Map-Request to a configured Map-Resolver 1356 when it needs an EID-to-RLOC mapping that is not found in its local 1357 Map-Cache. Using the Map-Resolver greatly reduces both the 1358 complexity of the ITR implementation and the costs associated with 1359 its operation. 1361 In response to an Encapsulated Map-Request, the ITR can expect one of 1362 the following: 1364 o An immediate Negative Map-Reply (with action code of "Natively- 1365 Forward", 15-minute Time to Live (TTL)) from the Map-Resolver if 1366 the Map-Resolver can determine that the requested EID does not 1367 exist. The ITR saves the EID-Prefix returned in the Map-Reply in 1368 its cache, marks it as non-LISP-capable, and knows not to attempt 1369 LISP encapsulation for destinations matching it. 1371 o A Negative Map-Reply, with action code of "Natively-Forward", from 1372 a Map-Server that is authoritative for an EID-Prefix that matches 1373 the requested EID but that does not have an actively registered, 1374 more-specific ID-prefix. In this case, the requested EID is said 1375 to match a "hole" in the authoritative EID-Prefix. If the 1376 requested EID matches a more-specific EID-Prefix that has been 1377 delegated by the Map-Server but for which no ETRs are currently 1378 registered, a 1-minute TTL is returned. If the requested EID 1379 matches a non-delegated part of the authoritative EID-Prefix, then 1380 it is not a LISP EID and a 15-minute TTL is returned. See 1381 Section 8.2 for discussion of aggregate EID-Prefixes and details 1382 of Map-Server EID-Prefix matching. 1384 o A LISP Map-Reply from the ETR that owns the EID-to-RLOC mapping or 1385 possibly from a Map-Server answering on behalf of the ETR. See 1386 Section 8.4 for more details on Map-Resolver message processing. 1388 Note that an ITR MAY be configured to both use a Map-Resolver and to 1389 participate in a LISP-ALT logical network. In such a situation, the 1390 ITR SHOULD send Map-Requests through the ALT network for any EID- 1391 Prefix learned via ALT BGP. Such a configuration is expected to be 1392 very rare, since there is little benefit to using a Map-Resolver if 1393 an ITR is already using LISP-ALT. There would be, for example, no 1394 need for such an ITR to send a Map-Request to a possibly non-existent 1395 EID (and rely on Negative Map-Replies) if it can consult the ALT 1396 database to verify that an EID-Prefix is present before sending that 1397 Map-Request. 1399 8.2. EID-Prefix Configuration and ETR Registration 1401 An ETR publishes its EID-Prefixes on a Map-Server by sending LISP 1402 Map-Register messages. A Map-Register message includes 1403 authentication data, so prior to sending a Map-Register message, the 1404 ETR and Map-Server SHOULD be configured with a shared secret or other 1405 relevant authentication information. A Map-Server's configuration 1406 SHOULD also include a list of the EID-Prefixes for which each ETR is 1407 authoritative. Upon receipt of a Map-Register from an ETR, a Map- 1408 Server accepts only EID-Prefixes that are configured for that ETR. 1409 Failure to implement such a check would leave the mapping system 1410 vulnerable to trivial EID-Prefix hijacking attacks. As developers 1411 and operators gain experience with the mapping system, additional, 1412 stronger security measures MAY be added to the registration process. 1414 In addition to the set of EID-Prefixes defined for each ETR that MAY 1415 register, a Map-Server is typically also configured with one or more 1416 aggregate prefixes that define the part of the EID numbering space 1417 assigned to it. When LISP-ALT is the database in use, aggregate EID- 1418 Prefixes are implemented as discard routes and advertised into ALT 1419 BGP. The existence of aggregate EID-Prefixes in a Map-Server's 1420 database means that it MAY receive Map Requests for EID-Prefixes that 1421 match an aggregate but do not match a registered prefix; Section 8.3 1422 describes how this is handled. 1424 Map-Register messages are sent periodically from an ETR to a Map- 1425 Server with a suggested interval between messages of one minute. A 1426 Map-Server SHOULD time out and remove an ETR's registration if it has 1427 not received a valid Map-Register message within the past 1428 three minutes. When first contacting a Map-Server after restart or 1429 changes to its EID-to-RLOC database mappings, an ETR MAY initially 1430 send Map-Register messages at an increased frequency, up to one every 1431 20 seconds. This "quick registration" period is limited to 1432 five minutes in duration. 1434 An ETR MAY request that a Map-Server explicitly acknowledge receipt 1435 and processing of a Map-Register message by setting the "want-map- 1436 notify" (M-bit) flag. A Map-Server that receives a Map-Register with 1437 this flag set will respond with a Map-Notify message. Typical use of 1438 this flag by an ETR would be to set it for Map-Register messages sent 1439 during the initial "quick registration" with a Map-Server but then 1440 set it only occasionally during steady-state maintenance of its 1441 association with that Map-Server. Note that the Map-Notify message 1442 is sent to UDP destination port 4342, not to the source port 1443 specified in the original Map-Register message. 1445 Note that a one-minute minimum registration interval during 1446 maintenance of an ETR-Map-Server association places a lower bound on 1447 how quickly and how frequently a mapping database entry can be 1448 updated. This MAY have implications for what sorts of mobility can 1449 be supported directly by the mapping system; shorter registration 1450 intervals or other mechanisms might be needed to support faster 1451 mobility in some cases. For a discussion on one way that faster 1452 mobility MAY be implemented for individual devices, please see 1453 [I-D.ietf-lisp-mn]. 1455 An ETR MAY also request, by setting the "proxy Map-Reply" flag 1456 (P-bit) in the Map-Register message, that a Map-Server answer Map- 1457 Requests instead of forwarding them to the ETR. See Section 7.1 for 1458 details on how the Map-Server sets certain flags (such as those 1459 indicating whether the message is authoritative and how returned 1460 Locators SHOULD be treated) when sending a Map-Reply on behalf of an 1461 ETR. When an ETR requests proxy reply service, it SHOULD include all 1462 RLOCs for all ETRs for the EID-Prefix being registered, along with 1463 the routable flag ("R-bit") setting for each RLOC. The Map-Server 1464 includes all of this information in Map-Reply messages that it sends 1465 on behalf of the ETR. This differs from a non-proxy registration, 1466 since the latter need only provide one or more RLOCs for a Map-Server 1467 to use for forwarding Map-Requests; the registration information is 1468 not used in Map-Replies, so it being incomplete is not incorrect. 1470 An ETR that uses a Map-Server to publish its EID-to-RLOC mappings 1471 does not need to participate further in the mapping database 1472 protocol(s). When using a LISP-ALT mapping database, for example, 1473 this means that the ETR does not need to implement GRE or BGP, which 1474 greatly simplifies its configuration and reduces its cost of 1475 operation. 1477 Note that use of a Map-Server does not preclude an ETR from also 1478 connecting to the mapping database (i.e., it could also connect to 1479 the LISP-ALT network), but doing so doesn't seem particularly useful, 1480 as the whole purpose of using a Map-Server is to avoid the complexity 1481 of the mapping database protocols. 1483 8.3. Map-Server Processing 1485 Once a Map-Server has EID-Prefixes registered by its client ETRs, it 1486 can accept and process Map-Requests for them. 1488 In response to a Map-Request (received over the ALT if LISP-ALT is in 1489 use), the Map-Server first checks to see if the destination EID 1490 matches a configured EID-Prefix. If there is no match, the Map- 1491 Server returns a Negative Map-Reply with action code "Natively- 1492 Forward" and a 15-minute TTL. This MAY occur if a Map Request is 1493 received for a configured aggregate EID-Prefix for which no more- 1494 specific EID-Prefix exists; it indicates the presence of a non-LISP 1495 "hole" in the aggregate EID-Prefix. 1497 Next, the Map-Server checks to see if any ETRs have registered the 1498 matching EID-Prefix. If none are found, then the Map-Server returns 1499 a Negative Map-Reply with action code "Natively-Forward" and a 1500 1-minute TTL. 1502 If the EID-prefix is either registered or not registered to the 1503 mapping system and there is a policy in the Map-Server to have the 1504 requestor drop packets for the matching EID-prefix, then a Drop/ 1505 Policy-Denied action is returned. If the EID-prefix is registered or 1506 not registered and there is a authentication failure, then a Drop/ 1507 Authentication- failure action is returned. If either of these 1508 actions result as a temporary state in policy or authentication then 1509 a Send-Map-Request action with 1-minute TTL MAY be returned to allow 1510 the reqeustor to retry the Map-Request. 1512 If any of the registered ETRs for the EID-Prefix have requested proxy 1513 reply service, then the Map-Server answers the request instead of 1514 forwarding it. It returns a Map-Reply with the EID-Prefix, RLOCs, 1515 and other information learned through the registration process. 1517 If none of the ETRs have requested proxy reply service, then the Map- 1518 Server re-encapsulates and forwards the resulting Encapsulated Map- 1519 Request to one of the registered ETRs. It does not otherwise alter 1520 the Map-Request, so any Map-Reply sent by the ETR is returned to the 1521 RLOC in the Map-Request, not to the Map-Server. Unless also acting 1522 as a Map-Resolver, a Map-Server SHOULD never receive Map-Replies; any 1523 such messages SHOULD be discarded without response, perhaps 1524 accompanied by the logging of a diagnostic message if the rate of 1525 Map-Replies is suggestive of malicious traffic. 1527 8.4. Map-Resolver Processing 1529 Upon receipt of an Encapsulated Map-Request, a Map-Resolver 1530 decapsulates the enclosed message and then searches for the requested 1531 EID in its local database of mapping entries (statically configured 1532 or learned from associated ETRs if the Map-Resolver is also a Map- 1533 Server offering proxy reply service). If it finds a matching entry, 1534 it returns a LISP Map-Reply with the known mapping. 1536 If the Map-Resolver does not have the mapping entry and if it can 1537 determine that the EID is not in the mapping database (for example, 1538 if LISP-ALT is used, the Map-Resolver will have an ALT forwarding 1539 table that covers the full EID space), it immediately returns a 1540 negative LISP Map-Reply, with action code "Natively-Forward" and a 1541 15-minute TTL. To minimize the number of negative cache entries 1542 needed by an ITR, the Map-Resolver SHOULD return the least-specific 1543 prefix that both matches the original query and does not match any 1544 EID-Prefix known to exist in the LISP-capable infrastructure. 1546 If the Map-Resolver does not have sufficient information to know 1547 whether the EID exists, it needs to forward the Map-Request to 1548 another device that has more information about the EID being 1549 requested. To do this, it forwards the unencapsulated Map-Request, 1550 with the original ITR RLOC as the source, to the mapping database 1551 system. Using LISP-ALT, the Map-Resolver is connected to the ALT 1552 network and sends the Map-Request to the next ALT hop learned from 1553 its ALT BGP neighbors. The Map-Resolver does not send any response 1554 to the ITR; since the source RLOC is that of the ITR, the ETR or Map- 1555 Server that receives the Map-Request over the ALT and responds will 1556 do so directly to the ITR. 1558 8.4.1. Anycast Map-Resolver Operation 1560 A Map-Resolver can be set up to use "anycast", where the same address 1561 is assigned to multiple Map-Resolvers and is propagated through IGP 1562 routing, to facilitate the use of a topologically close Map-Resolver 1563 by each ITR. 1565 Note that Map-Server associations with ETRs SHOULD NOT use anycast 1566 addresses, as registrations need to be established between an ETR and 1567 a specific set of Map-Servers, each identified by a specific 1568 registration association. 1570 9. Security Considerations 1572 The 2-way LISP header nonce exchange documented in 1573 [I-D.ietf-lisp-rfc6830bis] can be used to avoid ITR spoofing attacks. 1575 To publish an authoritative EID-to-RLOC mapping with a Map-Server, an 1576 ETR includes authentication data that is a hash of the message using 1577 a pair-wise shared key. An implementation MUST support use of HMAC- 1578 SHA-1-96 [RFC2104] and SHOULD support use of HMAC-SHA-256-128 1579 [RFC6234] (SHA-256 truncated to 128 bits). 1581 As noted in Section 8.2, a Map-Server SHOULD verify that all EID- 1582 Prefixes registered by an ETR match the configuration stored on the 1583 Map-Server. 1585 The currently defined authentication mechanism for Map-Register 1586 messages does not provide protection against "replay" attacks by a 1587 "man-in-the-middle". Additional work is needed in this area. 1589 [I-D.ietf-lisp-sec] defines a proposed mechanism for providing origin 1590 authentication, integrity, anti-replay protection, and prevention of 1591 man-in-the-middle and "overclaiming" attacks on the Map-Request/Map- 1592 Reply exchange. Work is ongoing on this and other proposals for 1593 resolving these open security issues. 1595 While beyond the scope of securing an individual Map-Server or Map- 1596 Resolver, it SHOULD be noted that a BGP-based LISP-ALT network (if 1597 ALT is used as the mapping database infrastructure) can take 1598 advantage of standards work on adding security to BGP. 1600 A complete LISP threat analysis has been published in [RFC7835]. 1601 Please refer to it for more security related details. 1603 10. IANA Considerations 1605 This section provides guidance to the Internet Assigned Numbers 1606 Authority (IANA) regarding registration of values related to this 1607 LISP Control-Plane specification, in accordance with BCP 26 1608 [RFC8126]. 1610 There are three namespaces (listed in the sub-sections below) in LISP 1611 that have been registered. 1613 o LISP IANA registry allocations SHOULD NOT be made for purposes 1614 unrelated to LISP routing or transport protocols. 1616 o The following policies are used here with the meanings defined in 1617 BCP 26: "Specification Required", "IETF Review", "Experimental 1618 Use", and "First Come First Served". 1620 10.1. LISP UDP Port Numbers 1622 The IANA registry has allocated UDP port number 4342 for the LISP 1623 Control-Plane. IANA has updated the description for UDP port 4342 as 1624 follows: 1626 Keyword Port Transport Layer Description 1627 ------- ---- --------------- ----------- 1628 lisp-control 4342 udp LISP Control Packets 1630 10.2. LISP Packet Type Codes 1632 It is being requested that the IANA be authoritative for LISP Packet 1633 Type definitions and that it refers to this document as well as 1634 [RFC8113] as references. 1636 Based on deployment experience of [RFC6830], the Map-Notify-Ack 1637 message, message type 5, was added to this document. This document 1638 requests IANA to add it to the LISP Packet Type Registry. 1640 Name Number Defined in 1641 ---- ------ ----------- 1642 LISP Map-Notify-Ack 5 RFC6833bis 1644 10.3. LISP ACT and Flag Fields 1646 New ACT values can be allocated through IETF review or IESG approval. 1647 Four values have already been allocated by [RFC6830]. This 1648 specification changes the name of ACT type 3 value from "Drop" to 1649 "Drop/No-Reason" as well as adding two new ACT values, the "Drop/ 1650 Policy-Denied" (type 4) and "Drop/Authentication-Failure" (type 5). 1652 Value Action Description Reference 1653 ----- ------ ----------- --------- 1654 4 Drop/ A Packet matching this Map-Cache RFC6833bis 1655 Policy-Denied entry is dropped because the target 1656 EID is policy-denied by the xTR or 1657 the mapping system. 1659 5 Drop/ A Packet matching this Map-Cache RFC6833bis 1660 Auth-Failure entry is dropped because the 1661 Map-Request for target EID fails an 1662 authentication check by the xTR or 1663 the mapping system. 1665 In addition, LISP has a number of flag fields and reserved fields, 1666 such as the LISP header flags field [I-D.ietf-lisp-rfc6830bis]. New 1667 bits for flags in these fields can be implemented after IETF review 1668 or IESG approval, but these need not be managed by IANA. 1670 10.4. LISP Address Type Codes 1672 LISP Canonical Address Format (LCAF) [RFC8060] is an 8-bit field that 1673 defines LISP-specific encodings for AFI value 16387. LCAF encodings 1674 are used for specific use-cases where different address types for 1675 EID-records and RLOC-records are required. 1677 The IANA registry "LISP Canonical Address Format (LCAF) Types" is 1678 used for LCAF types, the registry for LCAF types use the 1679 Specification Required policy [RFC8126]. Initial values for the 1680 registry as well as further information can be found in [RFC8060]. 1682 Therefore, there is no longer a need for the "LISP Address Type 1683 Codes" registry requested by [RFC6830]. This document requests to 1684 remove it. 1686 10.5. LISP Algorithm ID Numbers 1688 In [RFC6830], a request for a "LISP Key ID Numbers" registry was 1689 submitted. This document renames the registry to "LISP Algorithm ID 1690 Numbers" and requests the IANA to make the name change. 1692 The following Algorithm ID values are defined by this specification 1693 as used in any packet type that references a 'Algorithm ID' field: 1695 Name Number Defined in 1696 ----------------------------------------------- 1697 None 0 RFC6833bis 1698 HMAC-SHA-1-96 1 [RFC2404] 1699 HMAC-SHA-256-128 2 [RFC4868] 1701 Number values are in the range of 0 to 255. The allocation of values 1702 is on a first come first served basis. 1704 11. References 1706 11.1. Normative References 1708 [RFC2404] Madson, C. and R. Glenn, "The Use of HMAC-SHA-1-96 within 1709 ESP and AH", RFC 2404, DOI 10.17487/RFC2404, November 1710 1998, . 1712 [RFC4086] Eastlake 3rd, D., Schiller, J., and S. Crocker, 1713 "Randomness Requirements for Security", BCP 106, RFC 4086, 1714 DOI 10.17487/RFC4086, June 2005, 1715 . 1717 [RFC4868] Kelly, S. and S. Frankel, "Using HMAC-SHA-256, HMAC-SHA- 1718 384, and HMAC-SHA-512 with IPsec", RFC 4868, 1719 DOI 10.17487/RFC4868, May 2007, 1720 . 1722 11.2. Informative References 1724 [AFI] IANA, "Address Family Identifier (AFIs)", ADDRESS FAMILY 1725 NUMBERS http://www.iana.org/assignments/address-family- 1726 numbers/address-family-numbers.xhtml?, Febuary 2007. 1728 [I-D.ermagan-lisp-nat-traversal] 1729 Ermagan, V., Farinacci, D., Lewis, D., Skriver, J., Maino, 1730 F., and C. White, "NAT traversal for LISP", draft-ermagan- 1731 lisp-nat-traversal-14 (work in progress), April 2018. 1733 [I-D.herbert-intarea-ila] 1734 Herbert, T. and P. Lapukhov, "Identifier-locator 1735 addressing for IPv6", draft-herbert-intarea-ila-01 (work 1736 in progress), March 2018. 1738 [I-D.ietf-lisp-eid-mobility] 1739 Portoles-Comeras, M., Ashtaputre, V., Moreno, V., Maino, 1740 F., and D. Farinacci, "LISP L2/L3 EID Mobility Using a 1741 Unified Control Plane", draft-ietf-lisp-eid-mobility-02 1742 (work in progress), May 2018. 1744 [I-D.ietf-lisp-introduction] 1745 Cabellos-Aparicio, A. and D. Saucez, "An Architectural 1746 Introduction to the Locator/ID Separation Protocol 1747 (LISP)", draft-ietf-lisp-introduction-13 (work in 1748 progress), April 2015. 1750 [I-D.ietf-lisp-mn] 1751 Farinacci, D., Lewis, D., Meyer, D., and C. White, "LISP 1752 Mobile Node", draft-ietf-lisp-mn-02 (work in progress), 1753 April 2018. 1755 [I-D.ietf-lisp-rfc6830bis] 1756 Farinacci, D., Fuller, V., Meyer, D., Lewis, D., and A. 1757 Cabellos-Aparicio, "The Locator/ID Separation Protocol 1758 (LISP)", draft-ietf-lisp-rfc6830bis-13 (work in progress), 1759 July 2018. 1761 [I-D.ietf-lisp-sec] 1762 Maino, F., Ermagan, V., Cabellos-Aparicio, A., and D. 1763 Saucez, "LISP-Security (LISP-SEC)", draft-ietf-lisp-sec-15 1764 (work in progress), April 2018. 1766 [I-D.ietf-opsec-icmp-filtering] 1767 Gont, F., Gont, G., and C. Pignataro, "Recommendations for 1768 filtering ICMP messages", draft-ietf-opsec-icmp- 1769 filtering-04 (work in progress), July 2013. 1771 [I-D.lewis-lisp-gpe] 1772 Lewis, D., Lemon, J., Agarwal, P., Kreeger, L., Quinn, P., 1773 Smith, M., Yadav, N., and F. Maino, "LISP Generic Protocol 1774 Extension", draft-lewis-lisp-gpe-04 (work in progress), 1775 December 2017. 1777 [I-D.meyer-loc-id-implications] 1778 Meyer, D. and D. Lewis, "Architectural Implications of 1779 Locator/ID Separation", draft-meyer-loc-id-implications-01 1780 (work in progress), January 2009. 1782 [I-D.quinn-vxlan-gpe] 1783 Quinn, P., Manur, R., Kreeger, L., Lewis, D., Maino, F., 1784 Smith, M., Agarwal, P., Yong, L., Xu, X., Elzur, U., Garg, 1785 P., and D. Melman, "Generic Protocol Extension for VXLAN", 1786 draft-quinn-vxlan-gpe-04 (work in progress), February 1787 2015. 1789 [I-D.rodrigueznatal-lisp-oam] 1790 Rodriguez-Natal, A., Cabellos-Aparicio, A., Portoles- 1791 Comeras, M., Kowal, M., Lewis, D., and F. Maino, "LISP-OAM 1792 (Operations, Administration and Management): Use cases and 1793 requirements", draft-rodrigueznatal-lisp-oam-08 (work in 1794 progress), June 2018. 1796 [I-D.rodrigueznatal-lisp-pubsub] 1797 Rodriguez-Natal, A., Ermagan, V., Leong, J., Maino, F., 1798 Cabellos-Aparicio, A., Barkai, S., Farinacci, D., 1799 Boucadair, M., Jacquenet, C., and S. Secci, "Publish/ 1800 Subscribe Functionality for LISP", draft-rodrigueznatal- 1801 lisp-pubsub-02 (work in progress), March 2018. 1803 [RFC1035] Mockapetris, P., "Domain names - implementation and 1804 specification", STD 13, RFC 1035, DOI 10.17487/RFC1035, 1805 November 1987, . 1807 [RFC1071] Braden, R., Borman, D., and C. Partridge, "Computing the 1808 Internet checksum", RFC 1071, DOI 10.17487/RFC1071, 1809 September 1988, . 1811 [RFC2104] Krawczyk, H., Bellare, M., and R. Canetti, "HMAC: Keyed- 1812 Hashing for Message Authentication", RFC 2104, 1813 DOI 10.17487/RFC2104, February 1997, 1814 . 1816 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 1817 Requirement Levels", BCP 14, RFC 2119, 1818 DOI 10.17487/RFC2119, March 1997, 1819 . 1821 [RFC6234] Eastlake 3rd, D. and T. Hansen, "US Secure Hash Algorithms 1822 (SHA and SHA-based HMAC and HKDF)", RFC 6234, 1823 DOI 10.17487/RFC6234, May 2011, 1824 . 1826 [RFC6830] Farinacci, D., Fuller, V., Meyer, D., and D. Lewis, "The 1827 Locator/ID Separation Protocol (LISP)", RFC 6830, 1828 DOI 10.17487/RFC6830, January 2013, 1829 . 1831 [RFC6831] Farinacci, D., Meyer, D., Zwiebel, J., and S. Venaas, "The 1832 Locator/ID Separation Protocol (LISP) for Multicast 1833 Environments", RFC 6831, DOI 10.17487/RFC6831, January 1834 2013, . 1836 [RFC6832] Lewis, D., Meyer, D., Farinacci, D., and V. Fuller, 1837 "Interworking between Locator/ID Separation Protocol 1838 (LISP) and Non-LISP Sites", RFC 6832, 1839 DOI 10.17487/RFC6832, January 2013, 1840 . 1842 [RFC6834] Iannone, L., Saucez, D., and O. Bonaventure, "Locator/ID 1843 Separation Protocol (LISP) Map-Versioning", RFC 6834, 1844 DOI 10.17487/RFC6834, January 2013, 1845 . 1847 [RFC6836] Fuller, V., Farinacci, D., Meyer, D., and D. Lewis, 1848 "Locator/ID Separation Protocol Alternative Logical 1849 Topology (LISP+ALT)", RFC 6836, DOI 10.17487/RFC6836, 1850 January 2013, . 1852 [RFC6837] Lear, E., "NERD: A Not-so-novel Endpoint ID (EID) to 1853 Routing Locator (RLOC) Database", RFC 6837, 1854 DOI 10.17487/RFC6837, January 2013, 1855 . 1857 [RFC7215] Jakab, L., Cabellos-Aparicio, A., Coras, F., Domingo- 1858 Pascual, J., and D. Lewis, "Locator/Identifier Separation 1859 Protocol (LISP) Network Element Deployment 1860 Considerations", RFC 7215, DOI 10.17487/RFC7215, April 1861 2014, . 1863 [RFC7348] Mahalingam, M., Dutt, D., Duda, K., Agarwal, P., Kreeger, 1864 L., Sridhar, T., Bursell, M., and C. Wright, "Virtual 1865 eXtensible Local Area Network (VXLAN): A Framework for 1866 Overlaying Virtualized Layer 2 Networks over Layer 3 1867 Networks", RFC 7348, DOI 10.17487/RFC7348, August 2014, 1868 . 1870 [RFC7835] Saucez, D., Iannone, L., and O. Bonaventure, "Locator/ID 1871 Separation Protocol (LISP) Threat Analysis", RFC 7835, 1872 DOI 10.17487/RFC7835, April 2016, 1873 . 1875 [RFC8060] Farinacci, D., Meyer, D., and J. Snijders, "LISP Canonical 1876 Address Format (LCAF)", RFC 8060, DOI 10.17487/RFC8060, 1877 February 2017, . 1879 [RFC8111] Fuller, V., Lewis, D., Ermagan, V., Jain, A., and A. 1880 Smirnov, "Locator/ID Separation Protocol Delegated 1881 Database Tree (LISP-DDT)", RFC 8111, DOI 10.17487/RFC8111, 1882 May 2017, . 1884 [RFC8113] Boucadair, M. and C. Jacquenet, "Locator/ID Separation 1885 Protocol (LISP): Shared Extension Message & IANA Registry 1886 for Packet Type Allocations", RFC 8113, 1887 DOI 10.17487/RFC8113, March 2017, 1888 . 1890 [RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for 1891 Writing an IANA Considerations Section in RFCs", BCP 26, 1892 RFC 8126, DOI 10.17487/RFC8126, June 2017, 1893 . 1895 [RFC8378] Moreno, V. and D. Farinacci, "Signal-Free Locator/ID 1896 Separation Protocol (LISP) Multicast", RFC 8378, 1897 DOI 10.17487/RFC8378, May 2018, 1898 . 1900 Appendix A. Acknowledgments 1902 The authors would like to thank Greg Schudel, Darrel Lewis, John 1903 Zwiebel, Andrew Partan, Dave Meyer, Isidor Kouvelas, Jesper Skriver, 1904 Fabio Maino, and members of the lisp@ietf.org mailing list for their 1905 feedback and helpful suggestions. 1907 Special thanks are due to Noel Chiappa for his extensive work and 1908 thought about caching in Map-Resolvers. 1910 Appendix B. Document Change Log 1912 [RFC Editor: Please delete this section on publication as RFC.] 1914 B.1. Changes to draft-ietf-lisp-rfc6833bis-11 1916 o Posted July 2018. 1918 o Fixed Luigi editorial comments to ready draft for RFC status and 1919 ran through IDNITs again. 1921 B.2. Changes to draft-ietf-lisp-rfc6833bis-10 1923 o Posted after LISP WG at IETF week March. 1925 o Move AD field encoding after S-bit in the ECM packet format 1926 description section. 1928 o Say more about when the new Drop actions should be sent. 1930 B.3. Changes to draft-ietf-lisp-rfc6833bis-09 1932 o Posted March IETF week 2018. 1934 o Fixed editorial comments submitted by document shepherd Luigi 1935 Iannone. 1937 B.4. Changes to draft-ietf-lisp-rfc6833bis-08 1939 o Posted March 2018. 1941 o Added RLOC-probing algorithm. 1943 o Added Solicit-Map Request algorithm. 1945 o Added several mechanisms (from 6830bis) regarding Routing Locator 1946 Reachability. 1948 o Added port 4342 to IANA Considerations section. 1950 B.5. Changes to draft-ietf-lisp-rfc6833bis-07 1952 o Posted December 2017. 1954 o Make it more clear in a couple of places that RLOCs are used to 1955 locate ETRs more so than for Map-Server Map-Request forwarding. 1957 o Make it clear that "encapsualted" for a control message is an ECM 1958 based message. 1960 o Make it more clear what messages use source-port 4342 and which 1961 ones use destinatino-port 4342. 1963 o Don't make DDT references when the mapping transport system can be 1964 of any type and the referneced text is general to it. 1966 o Generalize text when referring to the format of an EID-prefix. 1967 Can use othe AFIs then IPv4 and IPv6. 1969 o Many editorial changes to clarify text. 1971 o Changed some "must", "should", and "may" to capitalized. 1973 o Added definitions for Map-Request and Map-Reply messages. 1975 o Ran document through IDNITs. 1977 B.6. Changes to draft-ietf-lisp-rfc6833bis-06 1979 o Posted October 2017. 1981 o Spec the I-bit to include the xTR-ID in a Map-Request message to 1982 be consistent with the Map-Register message and to anticipate the 1983 introduction of pubsub functionality to allow Map-Requests to 1984 subscribe to RLOC-set changes. 1986 o Updated references for individual submissions that became working 1987 group documents. 1989 o Updated references for working group documents that became RFCs. 1991 B.7. Changes to draft-ietf-lisp-rfc6833bis-05 1993 o Posted May 2017. 1995 o Update IANA Considerations section based on new requests from this 1996 document and changes from what was requested in [RFC6830]. 1998 B.8. Changes to draft-ietf-lisp-rfc6833bis-04 2000 o Posted May 2017. 2002 o Clarify how the Key-ID field is used in Map-Register and Map- 2003 Notify messages. Break the 16-bit field into a 8-bit Key-ID field 2004 and a 8-bit Algorithm-ID field. 2006 o Move the Control-Plane codepoints from the IANA Considerations 2007 section of RFC6830bis to the IANA Considerations section of this 2008 document. 2010 o In the "LISP Control Packet Type Allocations" section, indicate 2011 how message Types are IANA allocated and how experimental RFC8113 2012 sub-types should be requested. 2014 B.9. Changes to draft-ietf-lisp-rfc6833bis-03 2016 o Posted April 2017. 2018 o Add types 9-14 and specify they are not assigned. 2020 o Add the "LISP Shared Extension Message" type and point to RFC8113. 2022 B.10. Changes to draft-ietf-lisp-rfc6833bis-02 2024 o Posted April 2017. 2026 o Clarify that the LISP Control-Plane document defines how the LISP 2027 Data-Plane uses Map-Requests with either the SMR-bit set or the 2028 P-bit set supporting mapping updates and RLOC-probing. Indicating 2029 that other Data-Planes can use the same mechanisms or their own 2030 defined mechanisms to achieve the same functionality. 2032 B.11. Changes to draft-ietf-lisp-rfc6833bis-01 2034 o Posted March 2017. 2036 o Include references to new RFCs published. 2038 o Remove references to self. 2040 o Change references from RFC6830 to RFC6830bis. 2042 o Add two new action/reasons to a Map-Reply has posted to the LISP 2043 WG mailing list. 2045 o In intro section, add refernece to I-D.ietf-lisp-introduction. 2047 o Removed Open Issues section and references to "experimental". 2049 B.12. Changes to draft-ietf-lisp-rfc6833bis-00 2051 o Posted December 2016. 2053 o Created working group document from draft-farinacci-lisp 2054 -rfc6833-00 individual submission. No other changes made. 2056 B.13. Changes to draft-farinacci-lisp-rfc6833bis-00 2058 o Posted November 2016. 2060 o This is the initial draft to turn RFC 6833 into RFC 6833bis. 2062 o The document name has changed from the "Locator/ID Separation 2063 Protocol (LISP) Map-Server Interface" to the "Locator/ID 2064 Separation Protocol (LISP) Control-Plane". 2066 o The fundamental change was to move the Control-Plane messages from 2067 RFC 6830 to this document in an effort so any IETF developed or 2068 industry created Data-Plane could use the LISP mapping system and 2069 Control-Plane. 2071 o Update Control-Plane messages to incorporate what has been 2072 implemented in products during the early phase of LISP development 2073 but wasn't able to make it into RFC6830 and RFC6833 to make the 2074 Experimental RFC deadline. 2076 o Indicate there may be nodes in the mapping system that are not MRs 2077 or MSs, that is a ALT-node or a DDT-node. 2079 o Include LISP-DDT in Map-Resolver section and explain how they 2080 maintain a referral-cache. 2082 o Removed open issue about additional state in Map-Servers. With 2083 [RFC8111], Map-Servers have the same registration state and can 2084 give Map-Resolvers complete information in ms-ack Map-Referral 2085 messages. 2087 o Make reference to the LISP Threats Analysis RFC [RFC7835]. 2089 Authors' Addresses 2091 Vince Fuller 2092 Cisco Systems 2094 EMail: vaf@vaf.net 2096 Dino Farinacci 2097 Cisco Systems 2099 EMail: farinacci@gmail.com 2101 Albert Cabellos 2102 UPC/BarcelonaTech 2103 Campus Nord, C. Jordi Girona 1-3 2104 Barcelona, Catalunya 2105 Spain 2107 EMail: acabello@ac.upc.edu