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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 27, 2019 UPC/BarcelonaTech 7 July 26, 2018 9 Locator/ID Separation Protocol (LISP) Control-Plane 10 draft-ietf-lisp-rfc6833bis-12 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 27, 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-12 . . . . . . . . 44 102 B.2. Changes to draft-ietf-lisp-rfc6833bis-11 . . . . . . . . 44 103 B.3. Changes to draft-ietf-lisp-rfc6833bis-10 . . . . . . . . 44 104 B.4. Changes to draft-ietf-lisp-rfc6833bis-09 . . . . . . . . 44 105 B.5. Changes to draft-ietf-lisp-rfc6833bis-08 . . . . . . . . 44 106 B.6. Changes to draft-ietf-lisp-rfc6833bis-07 . . . . . . . . 45 107 B.7. Changes to draft-ietf-lisp-rfc6833bis-06 . . . . . . . . 45 108 B.8. Changes to draft-ietf-lisp-rfc6833bis-05 . . . . . . . . 46 109 B.9. Changes to draft-ietf-lisp-rfc6833bis-04 . . . . . . . . 46 110 B.10. Changes to draft-ietf-lisp-rfc6833bis-03 . . . . . . . . 46 111 B.11. Changes to draft-ietf-lisp-rfc6833bis-02 . . . . . . . . 46 112 B.12. Changes to draft-ietf-lisp-rfc6833bis-01 . . . . . . . . 46 113 B.13. Changes to draft-ietf-lisp-rfc6833bis-00 . . . . . . . . 47 114 B.14. Changes to draft-farinacci-lisp-rfc6833bis-00 . . . . . . 47 115 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 48 117 1. Introduction 119 The Locator/ID Separation Protocol [I-D.ietf-lisp-introduction] and 120 [I-D.ietf-lisp-rfc6830bis] specifies an architecture and mechanism 121 for dynamic tunnelling by logically separating the addresses 122 currently used by IP in two separate name spaces: Endpoint IDs 123 (EIDs), used within sites; and Routing Locators (RLOCs), used on the 124 transit networks that make up the Internet infrastructure. To 125 achieve this separation, LISP defines protocol mechanisms for mapping 126 from EIDs to RLOCs. In addition, LISP assumes the existence of a 127 database to store and propagate those mappings globally. Several 128 such databases have been proposed; among them are the Content 129 distribution Overlay Network Service for LISP-NERD (a Not-so-novel 130 EID-to-RLOC Database) [RFC6837], LISP Alternative Logical Topology 131 (LISP-ALT) [RFC6836], and LISP Delegated Database Tree (LISP-DDT) 132 [RFC8111]. 134 The LISP Mapping Service defines two new types of LISP-speaking 135 devices: the Map-Resolver, which accepts Map-Requests from an Ingress 136 Tunnel Router (ITR) and "resolves" the EID-to-RLOC mapping using a 137 mapping database; and the Map-Server, which learns authoritative EID- 138 to-RLOC mappings from an Egress Tunnel Router (ETR) and publishes 139 them in a database. 141 This LISP Control-Plane Mapping Service can be used by many different 142 encapsulation-based or translation-based Data-Planes which include 143 but are not limited to the ones defined in LISP RFC 6830bis 144 [I-D.ietf-lisp-rfc6830bis], LISP-GPE [I-D.lewis-lisp-gpe], VXLAN 146 [RFC7348], VXLAN-GPE [I-D.quinn-vxlan-gpe], and ILA 147 [I-D.herbert-intarea-ila]. 149 Conceptually, LISP Map-Servers share some of the same basic 150 configuration and maintenance properties as Domain Name System (DNS) 151 [RFC1035] servers; likewise, Map-Resolvers are conceptually similar 152 to DNS caching resolvers. With this in mind, this specification 153 borrows familiar terminology (resolver and server) from the DNS 154 specifications. 156 Note that while this document assumes a LISP-ALT database mapping 157 infrastructure to illustrate certain aspects of Map-Server and Map- 158 Resolver operation, the Mapping Service interface can (and likely 159 will) be used by ITRs and ETRs to access other mapping database 160 systems as the LISP infrastructure evolves. 162 The LISP Mapping Service is an important component of the LISP 163 toolset. Issues and concerns about the deployment of LISP for 164 Internet traffic are discussed in [I-D.ietf-lisp-rfc6830bis], 165 [RFC7215], and [I-D.rodrigueznatal-lisp-oam]. 167 This document obsoletes RFC 6833. 169 2. Requirements Notation 171 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 172 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 173 document are to be interpreted as described in [RFC2119]. 175 3. Definition of Terms 177 Map-Server: A network infrastructure component that learns of EID- 178 Prefix mapping entries from an ETR, via the registration mechanism 179 described below, or some other authoritative source if one exists. 180 A Map-Server publishes these EID-Prefixes in a mapping database. 182 Map-Request: A LISP Map-Request is a Control-Plane message to query 183 the mapping system to resolve an EID. A LISP Map-Request can also 184 be sent to an RLOC to test for reachability and to exchange 185 security keys between an encapsulator and a decapsulator. This 186 type of Map-Request is also known as an RLOC-Probe Request. 188 Map-Reply: A LISP Map-Reply is a Control-Plane message returned in 189 response to a Map-Request sent to the mapping system when 190 resolving an EID. A LISP Map-Reply can also be returned by a 191 decapsulator in response to a Map-Request sent by an encapsulator 192 to test for reachability. This type of Map-Reply is known as a 193 RLOC-Probe Reply. 195 Encapsulated Map-Request: A LISP Map-Request carried within an 196 Encapsulated Control Message (ECM), which has an additional LISP 197 header prepended. Sent to UDP destination port 4342. The "outer" 198 addresses are routable IP addresses, also known as RLOCs. Used by 199 an ITR when sending to a Map-Resolver and by a Map-Server when 200 forwarding a Map-Request to an ETR. 202 Map-Resolver: A network infrastructure component that accepts LISP 203 Encapsulated (ECM) Map-Requests, typically from an ITR, and 204 determines whether or not the destination IP address is part of 205 the EID namespace; if it is not, a Negative Map-Reply is returned. 206 Otherwise, the Map-Resolver finds the appropriate EID-to-RLOC 207 mapping by consulting a mapping database system. 209 Negative Map-Reply: A LISP Map-Reply that contains an empty 210 Locator-Set. Returned in response to a Map-Request if the 211 destination EID is not registered in the mapping system, is policy 212 denied or fails authentication. 214 Map-Register message: A LISP message sent by an ETR to a Map-Server 215 to register its associated EID-Prefixes. In addition to the set 216 of EID-Prefixes to register, the message includes one or more 217 RLOCs to reach ETR(s). The Map-Server uses these RLOCs when 218 forwarding Map-Requests (re-formatted as Encapsulated Map- 219 Requests). An ETR MAY request that the Map-Server answer Map- 220 Requests on its behalf by setting the "proxy Map-Reply" flag 221 (P-bit) in the message. 223 Map-Notify message: A LISP message sent by a Map-Server to an ETR 224 to confirm that a Map-Register has been received and processed. 225 An ETR requests that a Map-Notify be returned by setting the 226 "want-map-notify" flag (M-bit) in the Map-Register message. 227 Unlike a Map-Reply, a Map-Notify uses UDP port 4342 for both 228 source and destination. Map-Notify messages are also sent to ITRs 229 by Map-Servers when there are RLOC-set changes. 231 For definitions of other terms, notably Ingress Tunnel Router (ITR), 232 Egress Tunnel Router (ETR), and Re-encapsulating Tunnel Router (RTR), 233 refer to the LISP Data-Plane specification 234 [I-D.ietf-lisp-rfc6830bis]. 236 4. Basic Overview 238 A Map-Server is a device that publishes EID-Prefixes in a LISP 239 mapping database on behalf of a set of ETRs. When it receives a Map 240 Request (typically from an ITR), it consults the mapping database to 241 find an ETR that can answer with the set of RLOCs for an EID-Prefix. 242 To publish its EID-Prefixes, an ETR periodically sends Map-Register 243 messages to the Map-Server. A Map-Register message contains a list 244 of EID-Prefixes plus a set of RLOCs that can be used to reach the 245 ETRs. 247 When LISP-ALT [RFC6836] is used as the mapping database, a Map-Server 248 connects to the ALT network and acts as a "last-hop" ALT-Router. 249 Intermediate ALT-Routers forward Map-Requests to the Map-Server that 250 advertises a particular EID-Prefix, and the Map-Server forwards them 251 to the owning ETR, which responds with Map-Reply messages. 253 When LISP-DDT [RFC8111] is used as the mapping database, a Map-Server 254 sends the final Map-Referral messages from the Delegated Database 255 Tree. 257 A Map-Resolver receives Encapsulated Map-Requests from its client 258 ITRs and uses a mapping database system to find the appropriate ETR 259 to answer those requests. On a LISP-ALT network, a Map-Resolver acts 260 as a "first-hop" ALT-Router. It has Generic Routing Encapsulation 261 (GRE) tunnels configured to other ALT-Routers and uses BGP to learn 262 paths to ETRs for different prefixes in the LISP-ALT database. The 263 Map-Resolver uses this path information to forward Map-Requests over 264 the ALT to the correct ETRs. On a LISP-DDT network [RFC8111], a Map- 265 Resolver maintains a referral-cache and acts as a "first-hop" DDT- 266 node. The Map-Resolver uses the referral information to forward Map- 267 Requests. 269 Note that while it is conceivable that a Map-Resolver could cache 270 responses to improve performance, issues surrounding cache management 271 will need to be resolved so that doing so will be reliable and 272 practical. As initially deployed, Map-Resolvers will operate only in 273 a non-caching mode, decapsulating and forwarding Encapsulated Map 274 Requests received from ITRs. Any specification of caching 275 functionality is out of scope for this document. 277 Note that a single device can implement the functions of both a Map- 278 Server and a Map-Resolver, and in many cases the functions will be 279 co-located in that way. Also, there can be ALT-only nodes and DDT- 280 only nodes, when LISP-ALT and LISP-DDT are used, respectively, to 281 connecting Map-Resolvers and Map-Servers together to make up the 282 Mapping System. 284 5. LISP IPv4 and IPv6 Control-Plane Packet Formats 286 The following UDP packet formats are used by the LISP control plane. 288 0 1 2 3 289 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 1 290 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 291 |Version| IHL |Type of Service| Total Length | 292 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 293 | Identification |Flags| Fragment Offset | 294 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 295 | Time to Live | Protocol = 17 | Header Checksum | 296 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 297 | Source Routing Locator | 298 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 299 | Destination Routing Locator | 300 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 301 / | Source Port | Dest Port | 302 UDP +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 303 \ | UDP Length | UDP Checksum | 304 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 305 | | 306 | LISP Message | 307 | | 308 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 310 0 1 2 3 311 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 1 312 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 313 |Version| Traffic Class | Flow Label | 314 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 315 | Payload Length | Next Header=17| Hop Limit | 316 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 317 | | 318 + + 319 | | 320 + Source Routing Locator + 321 | | 322 + + 323 | | 324 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 325 | | 326 + + 327 | | 328 + Destination Routing Locator + 329 | | 330 + + 331 | | 332 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 333 / | Source Port | Dest Port | 334 UDP +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 335 \ | UDP Length | UDP Checksum | 336 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 337 | | 338 | LISP Message | 339 | | 340 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 342 When a UDP Map-Request, Map-Register, or Map-Notify (when used as a 343 notification message) are sent, the UDP source port is chosen by the 344 sender and the destination UDP port number is set to 4342. When a 345 UDP Map-Reply Map-Notify (when used as an acknowledgement to a Map- 346 Register), or Map-Notify-Ack are sent, the source UDP port number is 347 set to 4342 and the destination UDP port number is copied from the 348 source port of either the Map-Request or the invoking data packet. 349 Implementations MUST be prepared to accept packets when either the 350 source port or destination UDP port is set to 4342 due to NATs 351 changing port number values. 353 The 'UDP Length' field will reflect the length of the UDP header and 354 the LISP Message payload. 356 The UDP checksum is computed and set to non-zero for all messages 357 sent to or from port 4342. It MUST be checked on receipt, and if the 358 checksum fails, the control message MUST be dropped [RFC1071]. 360 The format of control messages includes the UDP header so the 361 checksum and length fields can be used to protect and delimit message 362 boundaries. 364 5.1. LISP Control Packet Type Allocations 366 This section defines the LISP control message formats and summarizes 367 for IANA the LISP Type codes assigned by this document. For 368 completeness, this document references the LISP Shared Extension 369 Message assigned by [RFC8113]. Message type definitions are: 371 Reserved: 0 b'0000' 372 LISP Map-Request: 1 b'0001' 373 LISP Map-Reply: 2 b'0010' 374 LISP Map-Register: 3 b'0011' 375 LISP Map-Notify: 4 b'0100' 376 LISP Map-Notify-Ack: 5 b'0101' 377 LISP Map-Referral: 6 b'0110' 378 LISP Encapsulated Control Message: 8 b'1000' 379 Not Assigned 9-14 b'1001'- b'1110' 380 LISP Shared Extension Message: 15 b'1111' [RFC8113] 382 Values in the "Not Assigned" range can be assigned according to 383 procedures in [RFC8126]. Documents that request for a new LISP 384 packet type MAY indicate a preferred value. 386 Protocol designers experimenting with new message formats SHOULD use 387 the LISP Shared Extension Message Type and request a [RFC8113] sub- 388 type assignment. 390 All LISP Control-Plane messages use Address Family Identifiers (AFI) 391 [AFI] or LISP Canonical Address Format (LCAF) [RFC8060] formats to 392 encode either fixed or variable length addresses. This includes 393 explicit fields in each control message or part of EID-records or 394 RLOC-records in commonly formatted messages. 396 The LISP control-plane describes how other data-planes can encode 397 messages to support the SMR and RLOC-probing procedures. 399 5.2. Map-Request Message Format 401 0 1 2 3 402 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 1 403 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 404 |Type=1 |A|M|P|S|p|s|m|I| Rsvd |L|D| IRC | Record Count | 405 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 406 | Nonce . . . | 407 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 408 | . . . Nonce | 409 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 410 | Source-EID-AFI | Source EID Address ... | 411 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 412 | ITR-RLOC-AFI 1 | ITR-RLOC Address 1 ... | 413 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 414 | ... | 415 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 416 | ITR-RLOC-AFI n | ITR-RLOC Address n ... | 417 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 418 / | Reserved | EID mask-len | EID-Prefix-AFI | 419 Rec +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 420 \ | EID-Prefix ... | 421 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 422 | Map-Reply Record ... | 423 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 425 Packet field descriptions: 427 Type: 1 (Map-Request) 429 A: This is an authoritative bit, which is set to 0 for UDP-based Map- 430 Requests sent by an ITR. It is set to 1 when an ITR wants the 431 destination site to return the Map-Reply rather than the mapping 432 database system. 434 M: This is the map-data-present bit. When set, it indicates that a 435 Map-Reply Record segment is included in the Map-Request. 437 P: This is the probe-bit, which indicates that a Map-Request SHOULD 438 be treated as a Locator reachability probe. The receiver SHOULD 439 respond with a Map-Reply with the probe-bit set, indicating that 440 the Map-Reply is a Locator reachability probe reply, with the 441 nonce copied from the Map-Request. See RLOC-Probing Section 7.1 442 for more details. 444 S: This is the Solicit-Map-Request (SMR) bit. See Solicit-Map- 445 Request (SMRs) Section 6.1 for details. 447 p: This is the PITR bit. This bit is set to 1 when a PITR sends a 448 Map-Request. 450 s: This is the SMR-invoked bit. This bit is set to 1 when an xTR is 451 sending a Map-Request in response to a received SMR-based Map- 452 Request. 454 m: This is the LISP mobile-node m-bit. This bit is set by xTRs that 455 operate as a mobile node as defined in [I-D.ietf-lisp-mn]. 457 I: This is the xTR-ID bit. When this bit is set, what is appended to 458 the Map-Request is a 128-bit xTR router-ID. See LISP PubSub usage 459 procedures in [I-D.rodrigueznatal-lisp-pubsub] for details. 461 Rsvd: This field MUST be set to 0 on transmit and MUST be ignored on 462 receipt. 464 L: This is the local-xtr bit. It is used by an xTR in a LISP site to 465 tell other xTRs in the same site that it is part of the RLOC-set 466 for the LISP site. The L-bit is set to 1 when the RLOC is the 467 sender's IP address. 469 D: This is the dont-map-reply bit. It is used in the SMR procedure 470 described in Section 6.1. When an xTR sends an SMR Map-Request 471 message, it doesn't need a Map-Reply returned. When this bit is 472 set, the receiver of the Map-Request does not return a Map-Reply. 474 IRC: This 5-bit field is the ITR-RLOC Count, which encodes the 475 additional number of ('ITR-RLOC-AFI', 'ITR-RLOC Address') fields 476 present in this message. At least one (ITR-RLOC-AFI, ITR-RLOC- 477 Address) pair MUST be encoded. Multiple 'ITR-RLOC Address' fields 478 are used, so a Map-Replier can select which destination address to 479 use for a Map-Reply. The IRC value ranges from 0 to 31. For a 480 value of 0, there is 1 ITR-RLOC address encoded; for a value of 1, 481 there are 2 ITR-RLOC addresses encoded, and so on up to 31, which 482 encodes a total of 32 ITR-RLOC addresses. 484 Record Count: This is the number of records in this Map-Request 485 message. A record is comprised of the portion of the packet that 486 is labeled 'Rec' above and occurs the number of times equal to 487 Record Count. For this version of the protocol, a receiver MUST 488 accept and process Map-Requests that contain one or more records, 489 but a sender MUST only send Map-Requests containing one record. 490 Support for requesting multiple EIDs in a single Map-Request 491 message will be specified in a future version of the protocol. 493 Nonce: This is an 8-octet random value created by the sender of the 494 Map-Request. This nonce will be returned in the Map-Reply. The 495 security of the LISP mapping protocol critically depends on the 496 strength of the nonce in the Map-Request message. The nonce 497 SHOULD be generated by a properly seeded pseudo-random (or strong 498 random) source. See [RFC4086] for advice on generating security- 499 sensitive random data. 501 Source-EID-AFI: This is the address family of the 'Source EID 502 Address' field. 504 Source EID Address: This is the EID of the source host that 505 originated the packet that caused the Map-Request. When Map- 506 Requests are used for refreshing a Map-Cache entry or for RLOC- 507 Probing, an AFI value 0 is used and this field is of zero length. 509 ITR-RLOC-AFI: This is the address family of the 'ITR-RLOC Address' 510 field that follows this field. 512 ITR-RLOC Address: This is used to give the ETR the option of 513 selecting the destination address from any address family for the 514 Map-Reply message. This address MUST be a routable RLOC address 515 of the sender of the Map-Request message. 517 EID mask-len: This is the mask length for the EID-Prefix. 519 EID-Prefix-AFI: This is the address family of the EID-Prefix 520 according to [AFI] and [RFC8060]. 522 EID-Prefix: This prefix is 4 octets for an IPv4 address family and 523 16 octets for an IPv6 address family when the EID-Prefix-AFI is 1 524 or 2, respectively. For other AFIs [AFI], the length varies and 525 for the LCAF AFI the format is defined in [RFC8060]. When a Map- 526 Request is sent by an ITR because a data packet is received for a 527 destination where there is no mapping entry, the EID-Prefix is set 528 to the destination IP address of the data packet, and the 'EID 529 mask-len' is set to 32 or 128 for IPv4 or IPv6, respectively. 530 When an xTR wants to query a site about the status of a mapping it 531 already has cached, the EID-Prefix used in the Map-Request has the 532 same mask length as the EID-Prefix returned from the site when it 533 sent a Map-Reply message. 535 Map-Reply Record: When the M-bit is set, this field is the size of a 536 single "Record" in the Map-Reply format. This Map-Reply record 537 contains the EID-to-RLOC mapping entry associated with the Source 538 EID. This allows the ETR that will receive this Map-Request to 539 cache the data if it chooses to do so. 541 5.3. EID-to-RLOC UDP Map-Request Message 543 A Map-Request is sent from an ITR when it needs a mapping for an EID, 544 wants to test an RLOC for reachability, or wants to refresh a mapping 545 before TTL expiration. For the initial case, the destination IP 546 address used for the Map-Request is the data packet's destination 547 address (i.e., the destination EID) that had a mapping cache lookup 548 failure. For the latter two cases, the destination IP address used 549 for the Map-Request is one of the RLOC addresses from the Locator-Set 550 of the Map-Cache entry. The source address is either an IPv4 or IPv6 551 RLOC address, depending on whether the Map-Request is using an IPv4 552 or IPv6 header, respectively. In all cases, the UDP source port 553 number for the Map-Request message is a 16-bit value selected by the 554 ITR/PITR, and the UDP destination port number is set to the well- 555 known destination port number 4342. A successful Map-Reply, which is 556 one that has a nonce that matches an outstanding Map-Request nonce, 557 will update the cached set of RLOCs associated with the EID-Prefix 558 range. 560 One or more Map-Request ('ITR-RLOC-AFI', 'ITR-RLOC-Address') fields 561 MUST be filled in by the ITR. The number of fields (minus 1) encoded 562 MUST be placed in the 'IRC' field. The ITR MAY include all locally 563 configured Locators in this list or just provide one locator address 564 from each address family it supports. If the ITR erroneously 565 provides no ITR-RLOC addresses, the Map-Replier MUST drop the Map- 566 Request. 568 Map-Requests can also be LISP encapsulated using UDP destination 569 port 4342 with a LISP Type value set to "Encapsulated Control 570 Message", when sent from an ITR to a Map-Resolver. Likewise, Map- 571 Requests are LISP encapsulated the same way from a Map-Server to an 572 ETR. Details on Encapsulated Map-Requests and Map-Resolvers can be 573 found in Section 5.8. 575 Map-Requests MUST be rate-limited. It is RECOMMENDED that a Map- 576 Request for the same EID-Prefix be sent no more than once per second. 578 An ITR that is configured with mapping database information (i.e., it 579 is also an ETR) MAY optionally include those mappings in a Map- 580 Request. When an ETR configured to accept and verify such 581 "piggybacked" mapping data receives such a Map-Request and it does 582 not have this mapping in the Map-Cache, it MAY originate a "verifying 583 Map-Request", addressed to the map-requesting ITR and the ETR MAY add 584 a Map-Cache entry. If the ETR has a Map-Cache entry that matches the 585 "piggybacked" EID and the RLOC is in the Locator-Set for the entry, 586 then it MAY send the "verifying Map-Request" directly to the 587 originating Map-Request source. If the RLOC is not in the Locator- 588 Set, then the ETR MUST send the "verifying Map-Request" to the 589 "piggybacked" EID. Doing this forces the "verifying Map-Request" to 590 go through the mapping database system to reach the authoritative 591 source of information about that EID, guarding against RLOC-spoofing 592 in the "piggybacked" mapping data. 594 5.4. Map-Reply Message Format 596 0 1 2 3 597 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 1 598 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 599 |Type=2 |P|E|S| Reserved | Record Count | 600 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 601 | Nonce . . . | 602 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 603 | . . . Nonce | 604 +-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 605 | | Record TTL | 606 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 607 R | Locator Count | EID mask-len | ACT |A| Reserved | 608 e +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 609 c | Rsvd | Map-Version Number | EID-Prefix-AFI | 610 o +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 611 r | EID-Prefix | 612 d +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 613 | /| Priority | Weight | M Priority | M Weight | 614 | L +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 615 | o | Unused Flags |L|p|R| Loc-AFI | 616 | c +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 617 | \| Locator | 618 +-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 620 Packet field descriptions: 622 Type: 2 (Map-Reply) 624 P: This is the probe-bit, which indicates that the Map-Reply is in 625 response to a Locator reachability probe Map-Request. The 'Nonce' 626 field MUST contain a copy of the nonce value from the original 627 Map-Request. See RLOC-probing Section 7.1 for more details. When 628 the probe-bit is set to 1 in a Map-Reply message, the A-bit in 629 each EID-record included in the message MUST be set to 1. 631 E: This bit indicates that the ETR that sends this Map-Reply message 632 is advertising that the site is enabled for the Echo-Nonce Locator 633 reachability algorithm. See Echo-Nonce [I-D.ietf-lisp-rfc6830bis] 634 for more details. 636 S: This is the Security bit. When set to 1, the following 637 authentication information will be appended to the end of the Map- 638 Reply. The details of signing a Map-Reply message can be found in 639 [I-D.ietf-lisp-sec]. 641 0 1 2 3 642 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 1 643 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 644 | AD Type | Authentication Data Content . . . | 645 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 647 Reserved: This field MUST be set to 0 on transmit and MUST be 648 ignored on receipt. 650 Record Count: This is the number of records in this reply message. 651 A record is comprised of that portion of the packet labeled 652 'Record' above and occurs the number of times equal to Record 653 Count. 655 Nonce: This is a 24-bit value set in a Data-Probe 656 [I-D.ietf-lisp-rfc6830bis] or a 64-bit value from the Map-Request 657 is echoed in this 'Nonce' field of the Map-Reply. When a 24-bit 658 value is supplied, it resides in the low-order 64 bits of the 659 'Nonce' field. 661 Record TTL: This is the time in minutes the recipient of the Map- 662 Reply will store the mapping. If the TTL is 0, the entry MUST be 663 removed from the cache immediately. If the value is 0xffffffff, 664 the recipient can decide locally how long to store the mapping. 666 Locator Count: This is the number of Locator entries. A Locator 667 entry comprises what is labeled above as 'Loc'. The Locator count 668 can be 0, indicating that there are no Locators for the EID- 669 Prefix. 671 EID mask-len: This is the mask length for the EID-Prefix. 673 ACT: This 3-bit field describes Negative Map-Reply actions. In any 674 other message type, these bits are set to 0 and ignored on 675 receipt. These bits are used only when the 'Locator Count' field 676 is set to 0. The action bits are encoded only in Map-Reply 677 messages. They are used to tell an ITR or PITR why a empty 678 locator-set was returned from the mapping system and how it stores 679 the map-cache entry. 681 (0) No-Action: The Map-Cache is kept alive, and no packet 682 encapsulation occurs. 684 (1) Natively-Forward: The packet is not encapsulated or dropped 685 but natively forwarded. 687 (2) Send-Map-Request: The Map-Cache entry is created and flagged 688 that any packet matching this entry invokes sending a Map- 689 Request. 691 (3) Drop/No-Reason: A packet that matches this Map-Cache entry is 692 dropped. An ICMP Destination Unreachable message SHOULD be 693 sent. 695 (4) Drop/Policy-Denied: A packet that matches this Map-Cache 696 entry is dropped. The reason for the Drop action is that a 697 Map-Request for the target-EID is being policy denied by 698 either an xTR or the mapping system. 700 (5) Drop/Authentication-Failure: A packet that matches this Map- 701 Cache entry is dropped. The reason for the Drop action is 702 that a Map-Request for the target-EID fails an authentication 703 verification-check by either an xTR or the mapping system. 705 A: The Authoritative bit, when sent, is always set to 1 by an ETR. 706 When a Map-Server is proxy Map-Replying for a LISP site, the 707 Authoritative bit is set to 0. This indicates to requesting ITRs 708 that the Map-Reply was not originated by a LISP node managed at 709 the site that owns the EID-Prefix. 711 Map-Version Number: When this 12-bit value is non-zero, the Map- 712 Reply sender is informing the ITR what the version number is for 713 the EID record contained in the Map-Reply. The ETR can allocate 714 this number internally but MUST coordinate this value with other 715 ETRs for the site. When this value is 0, there is no versioning 716 information conveyed. The Map-Version Number can be included in 717 Map-Request and Map-Register messages. See Map-Versioning 718 [I-D.ietf-lisp-6834bis] for more details. 720 EID-Prefix-AFI: Address family of the EID-Prefix according to [AFI] 721 and [RFC8060]. 723 EID-Prefix: This prefix is 4 octets for an IPv4 address family and 724 16 octets for an IPv6 address family. 726 Priority: Each RLOC is assigned a unicast Priority. Lower values 727 are more preferable. When multiple RLOCs have the same Priority, 728 they MAY be used in a load-split fashion. A value of 255 means 729 the RLOC MUST NOT be used for unicast forwarding. 731 Weight: When priorities are the same for multiple RLOCs, the Weight 732 indicates how to balance unicast traffic between them. Weight is 733 encoded as a relative weight of total unicast packets that match 734 the mapping entry. For example, if there are 4 Locators in a 735 Locator-Set, where the Weights assigned are 30, 20, 20, and 10, 736 the first Locator will get 37.5% of the traffic, the 2nd and 3rd 737 Locators will get 25% of the traffic, and the 4th Locator will get 738 12.5% of the traffic. If all Weights for a Locator-Set are equal, 739 the receiver of the Map-Reply will decide how to load-split the 740 traffic. See RLOC-hashing [I-D.ietf-lisp-rfc6830bis] for a 741 suggested hash algorithm to distribute the load across Locators 742 with the same Priority and equal Weight values. 744 M Priority: Each RLOC is assigned a multicast Priority used by an 745 ETR in a receiver multicast site to select an ITR in a source 746 multicast site for building multicast distribution trees. A value 747 of 255 means the RLOC MUST NOT be used for joining a multicast 748 distribution tree. For more details, see [RFC6831]. 750 M Weight: When priorities are the same for multiple RLOCs, the 751 Weight indicates how to balance building multicast distribution 752 trees across multiple ITRs. The Weight is encoded as a relative 753 weight (similar to the unicast Weights) of the total number of 754 trees built to the source site identified by the EID-Prefix. If 755 all Weights for a Locator-Set are equal, the receiver of the Map- 756 Reply will decide how to distribute multicast state across ITRs. 757 For more details, see [RFC6831]. 759 Unused Flags: These are set to 0 when sending and ignored on 760 receipt. 762 L: When this bit is set, the Locator is flagged as a local Locator to 763 the ETR that is sending the Map-Reply. When a Map-Server is doing 764 proxy Map-Replying for a LISP site, the L-bit is set to 0 for all 765 Locators in this Locator-Set. 767 p: When this bit is set, an ETR informs the RLOC-Probing ITR that the 768 locator address for which this bit is set is the one being RLOC- 769 probed and MAY be different from the source address of the Map- 770 Reply. An ITR that RLOC-probes a particular Locator MUST use this 771 Locator for retrieving the data structure used to store the fact 772 that the Locator is reachable. The p-bit is set for a single 773 Locator in the same Locator-Set. If an implementation sets more 774 than one p-bit erroneously, the receiver of the Map-Reply MUST 775 select the first Locator. The p-bit MUST NOT be set for Locator- 776 Set records sent in Map-Request and Map-Register messages. 778 R: This is set when the sender of a Map-Reply has a route to the 779 Locator in the Locator data record. This receiver MAY find this 780 useful to know if the Locator is up but not necessarily reachable 781 from the receiver's point of view. See also EID-Reachability 782 Section 7.1 for another way the R-bit MAY be used. 784 Locator: This is an IPv4 or IPv6 address (as encoded by the 'Loc- 785 AFI' field) assigned to an ETR. Note that the destination RLOC 786 address MAY be an anycast address. A source RLOC can be an 787 anycast address as well. The source or destination RLOC MUST NOT 788 be the broadcast address (255.255.255.255 or any subnet broadcast 789 address known to the router) and MUST NOT be a link-local 790 multicast address. The source RLOC MUST NOT be a multicast 791 address. The destination RLOC SHOULD be a multicast address if it 792 is being mapped from a multicast destination EID. 794 5.5. EID-to-RLOC UDP Map-Reply Message 796 A Map-Reply returns an EID-Prefix with a prefix length that is less 797 than or equal to the EID being requested. The EID being requested is 798 either from the destination field of an IP header of a Data-Probe or 799 the EID record of a Map-Request. The RLOCs in the Map-Reply are 800 routable IP addresses of all ETRs for the LISP site. Each RLOC 801 conveys status reachability but does not convey path reachability 802 from a requester's perspective. Separate testing of path 803 reachability is required. See RLOC-reachability Section 7.1 for 804 details. 806 Note that a Map-Reply MAY contain different EID-Prefix granularity 807 (prefix + length) than the Map-Request that triggers it. This might 808 occur if a Map-Request were for a prefix that had been returned by an 809 earlier Map-Reply. In such a case, the requester updates its cache 810 with the new prefix information and granularity. For example, a 811 requester with two cached EID-Prefixes that are covered by a Map- 812 Reply containing one less-specific prefix replaces the entry with the 813 less-specific EID-Prefix. Note that the reverse, replacement of one 814 less-specific prefix with multiple more-specific prefixes, can also 815 occur, not by removing the less-specific prefix but rather by adding 816 the more-specific prefixes that, during a lookup, will override the 817 less-specific prefix. 819 When an EID moves out of a LISP site [I-D.ietf-lisp-eid-mobility], 820 the database mapping system may have overlapping EID-prefixes. Or 821 when a LISP site is configured with multiple sets of ETRs that 822 support different EID-prefix lengths, the database mapping system may 823 have overlapping EID-prefixes. When overlapping EID-prefixes exist, 824 a Map-Request with an EID that best matches any EID-Prefix MUST be 825 returned in a single Map-Reply message. For instance, if an ETR had 826 database mapping entries for EID-Prefixes: 828 10.0.0.0/8 829 10.1.0.0/16 830 10.1.1.0/24 831 10.1.2.0/24 833 A Map-Request for EID 10.1.1.1 would cause a Map-Reply with a record 834 count of 1 to be returned with a mapping record EID-Prefix of 835 10.1.1.0/24. 837 A Map-Request for EID 10.1.5.5 would cause a Map-Reply with a record 838 count of 3 to be returned with mapping records for EID-Prefixes 839 10.1.0.0/16, 10.1.1.0/24, and 10.1.2.0/24. 841 Note that not all overlapping EID-Prefixes need to be returned but 842 only the more-specific entries (note that in the second example above 843 10.0.0.0/8 was not returned for requesting EID 10.1.5.5) for the 844 matching EID-Prefix of the requesting EID. When more than one EID- 845 Prefix is returned, all SHOULD use the same Time to Live value so 846 they can all time out at the same time. When a more-specific EID- 847 Prefix is received later, its Time to Live value in the Map-Reply 848 record can be stored even when other less-specific entries exist. 849 When a less-specific EID-Prefix is received later, its Map-Cache 850 expiration time SHOULD be set to the minimum expiration time of any 851 more-specific EID-Prefix in the Map-Cache. This is done so the 852 integrity of the EID-Prefix set is wholly maintained and so no more- 853 specific entries are removed from the Map-Cache while keeping less- 854 specific entries. 856 Map-Replies SHOULD be sent for an EID-Prefix no more often than once 857 per second to the same requesting router. For scalability, it is 858 expected that aggregation of EID addresses into EID-Prefixes will 859 allow one Map-Reply to satisfy a mapping for the EID addresses in the 860 prefix range, thereby reducing the number of Map-Request messages. 862 Map-Reply records can have an empty Locator-Set. A Negative Map- 863 Reply is a Map-Reply with an empty Locator-Set. Negative Map-Replies 864 convey special actions by the sender to the ITR or PITR that have 865 solicited the Map-Reply. There are two primary applications for 866 Negative Map-Replies. The first is for a Map-Resolver to instruct an 867 ITR or PITR when a destination is for a LISP site versus a non-LISP 868 site, and the other is to source quench Map-Requests that are sent 869 for non-allocated EIDs. 871 For each Map-Reply record, the list of Locators in a Locator-Set MUST 872 appear in the same order for each ETR that originates a Map-Reply 873 message. The Locator-Set MUST be sorted in order of ascending IP 874 address where an IPv4 locator address is considered numerically 'less 875 than' an IPv6 locator address. 877 When sending a Map-Reply message, the destination address is copied 878 from one of the 'ITR-RLOC' fields from the Map-Request. The ETR can 879 choose a locator address from one of the address families it 880 supports. For Data-Probes, the destination address of the Map-Reply 881 is copied from the source address of the Data-Probe message that is 882 invoking the reply. The source address of the Map-Reply is one of 883 the local IP addresses chosen to allow Unicast Reverse Path 884 Forwarding (uRPF) checks to succeed in the upstream service provider. 885 The destination port of a Map-Reply message is copied from the source 886 port of the Map-Request or Data-Probe, and the source port of the 887 Map-Reply message is set to the well-known UDP port 4342. 889 5.6. Map-Register Message Format 891 This section specifies the encoding format for the Map-Register 892 message. The message is sent in UDP with a destination UDP port of 893 4342 and a randomly selected UDP source port number. 895 The Map-Register message format is: 897 0 1 2 3 898 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 1 899 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 900 |Type=3 |P|S|I| Reserved |E|T|a|m|M| Record Count | 901 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 902 | Nonce . . . | 903 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 904 | . . . Nonce | 905 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 906 | Key ID | Algorithm ID | Authentication Data Length | 907 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 908 ~ Authentication Data ~ 909 +-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 910 | | Record TTL | 911 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 912 R | Locator Count | EID mask-len | ACT |A| Reserved | 913 e +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 914 c | Rsvd | Map-Version Number | EID-Prefix-AFI | 915 o +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 916 r | EID-Prefix | 917 d +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 918 | /| Priority | Weight | M Priority | M Weight | 919 | L +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 920 | o | Unused Flags |L|p|R| Loc-AFI | 921 | c +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 922 | \| Locator | 923 +-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 925 Packet field descriptions: 927 Type: 3 (Map-Register) 929 P: This is the proxy Map-Reply bit. When set to 1, an ETR sends a 930 Map-Register message requesting the Map-Server to proxy a Map- 931 Reply. The Map-Server will send non-authoritative Map-Replies on 932 behalf of the ETR. 934 S: This is the security-capable bit. When set, the procedures from 935 [I-D.ietf-lisp-sec] are supported. 937 I: This is the xTR-ID bit. When this bit is set, what is appended to 938 the Map-Register is a 128-bit xTR router-ID and then a 64-bit 939 site-ID. See LISP NAT-Traversal procedures in 940 [I-D.ermagan-lisp-nat-traversal] for details. 942 Reserved: This field MUST be set to 0 on transmit and MUST be 943 ignored on receipt. 945 E: This is the Map-Register EID-notify bit. This is used by a First- 946 Hop-Router (FHR) which discovers a dynamic-EID. This EID-notify 947 based Map-Register is sent by the FHR to the same site xTR that 948 propogates the Map-Register to the mapping system. The site xTR 949 keeps state to later Map-Notify the FHR after the EID has moves 950 away. See [I-D.ietf-lisp-eid-mobility] for a detailed use-case. 952 T: This is the use-TTL for timeout bit. When set to 1, the xTR wants 953 the Map-Server to time out registrations based on the value in the 954 "Record TTL" field of this message. 956 a: This is the merge-request bit. When set to 1, the xTR requests to 957 merge RLOC-records from different xTRs registering the same EID- 958 record. See signal-free multicast [RFC8378] for one use case 959 example. 961 m: This is the mobile-node bit. When set to 1, the registering xTR 962 supports the procedures in [I-D.ietf-lisp-mn]. 964 M: This is the want-map-notify bit. When set to 1, an ETR is 965 requesting a Map-Notify message to be returned in response to 966 sending a Map-Register message. The Map-Notify message sent by a 967 Map-Server is used to acknowledge receipt of a Map-Register 968 message. 970 Record Count: This is the number of records in this Map-Register 971 message. A record is comprised of that portion of the packet 972 labeled 'Record' above and occurs the number of times equal to 973 Record Count. 975 Nonce: This 8-octet 'Nonce' field is set to 0 in Map-Register 976 messages if no Map-Notify message is expected to acknowledge it. 977 Since the Map-Register message is authenticated, the 'Nonce' field 978 is not currently used for any security function but MAY be in the 979 future as part of an anti-replay solution. 981 Key ID: This is a configured key-id value that corresponds to a 982 shared-secret password that is used to authenticate the sender. 983 Multiple shared-secrets can be used to roll over keys in a non- 984 disruptive way. 986 Algorithm ID: This is the configured Message Authentication Code 987 (MAC) algorithm value used for the authentication function. See 988 Algorithm ID Numbers in the Section 10.5 for codepoint 989 assignments. 991 Authentication Data Length: This is the length in octets of the 992 'Authentication Data' field that follows this field. The length 993 of the 'Authentication Data' field is dependent on the MAC 994 algorithm used. The length field allows a device that doesn't 995 know the MAC algorithm to correctly parse the packet. 997 Authentication Data: This is the message digest used from the output 998 of the MAC algorithm. The entire Map-Register payload is 999 authenticated with this field preset to 0. After the MAC is 1000 computed, it is placed in this field. Implementations of this 1001 specification MUST include support for HMAC-SHA-1-96 [RFC2404], 1002 and support for HMAC-SHA-256-128 [RFC4868] is RECOMMENDED. 1004 The definition of the rest of the Map-Register can be found in EID- 1005 record description in Section 5.4. 1007 5.7. Map-Notify/Map-Notify-Ack Message Format 1009 This section specifies the encoding format for the Map-Notify and 1010 Map-Notify-Ack messages. The messages are sent inside a UDP packet 1011 with source and destination UDP ports equal to 4342. 1013 The Map-Notify and Map-Notify-Ack message formats are: 1015 0 1 2 3 1016 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 1017 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1018 |Type=4/5| Reserved | Record Count | 1019 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1020 | Nonce . . . | 1021 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1022 | . . . Nonce | 1023 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1024 | Key ID | Algorithm ID | Authentication Data Length | 1025 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1026 ~ Authentication Data ~ 1027 +-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1028 | | Record TTL | 1029 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1030 R | Locator Count | EID mask-len | ACT |A| Reserved | 1031 e +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1032 c | Rsvd | Map-Version Number | EID-Prefix-AFI | 1033 o +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1034 r | EID-Prefix | 1035 d +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1036 | /| Priority | Weight | M Priority | M Weight | 1037 | L +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1038 | o | Unused Flags |L|p|R| Loc-AFI | 1039 | c +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1040 | \| Locator | 1041 +-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1043 Packet field descriptions: 1045 Type: 4/5 (Map-Notify/Map-Notify-Ack) 1047 The Map-Notify message has the same contents as a Map-Register 1048 message. See the Map-Register section for field descriptions. 1050 The Map-Notify-Ack message has the same contents as a Map-Notify 1051 message. It is used to acknowledge the receipt of a Map-Notify and 1052 for the sender to stop retransmitting a Map-Notify with the same 1053 nonce. 1055 5.8. Encapsulated Control Message Format 1057 An Encapsulated Control Message (ECM) is used to encapsulate control 1058 packets sent between xTRs and the mapping database system. 1060 0 1 2 3 1061 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 1062 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1063 / | IPv4 or IPv6 Header | 1064 OH | (uses RLOC addresses) | 1065 \ | | 1066 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1067 / | Source Port = xxxx | Dest Port = 4342 | 1068 UDP +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1069 \ | UDP Length | UDP Checksum | 1070 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1071 LISP |Type=8 |S|D|E|M| Reserved | 1072 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1073 / | IPv4 or IPv6 Header | 1074 IH | (uses RLOC or EID addresses) | 1075 \ | | 1076 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1077 / | Source Port = xxxx | Dest Port = yyyy | 1078 UDP +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1079 \ | UDP Length | UDP Checksum | 1080 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1081 LCM | LISP Control Message | 1082 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1084 Packet header descriptions: 1086 OH: The outer IPv4 or IPv6 header, which uses RLOC addresses in the 1087 source and destination header address fields. 1089 UDP: The outer UDP header with destination port 4342. The source 1090 port is randomly allocated. The checksum field MUST be non- 1091 zero. 1093 LISP: Type 8 is defined to be a "LISP Encapsulated Control Message", 1094 and what follows is either an IPv4 or IPv6 header as encoded by 1095 the first 4 bits after the 'Reserved' field. 1097 Type: 8 (Encapsulated Control Message (ECM)) 1099 S: This is the Security bit. When set to 1, the field following 1100 the 'Reserved' field will have the following Authentication 1101 Data format and follow the procedures from [I-D.ietf-lisp-sec]. 1103 0 1 2 3 1104 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 1105 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1106 | AD Type | Authentication Data Content . . . | 1107 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1109 D: This is the DDT-bit. When set to 1, the sender is requesting a 1110 Map-Referral message to be returned. The details of this 1111 procedure are described in [RFC8111]. 1113 E: This is the to-ETR bit. When set to 1, the Map-Server's 1114 intention is to forward the ECM to an authoritative ETR. 1116 M: This is the to-MS bit. When set to 1, a Map-Request is being 1117 sent to a co-located Map-Resolver and Map-Server where the 1118 message can be processed directly by the Map-Server versus the 1119 Map-Resolver using the LISP-DDT procedures in [RFC8111]. 1121 IH: The inner IPv4 or IPv6 header, which can use either RLOC or EID 1122 addresses in the header address fields. When a Map-Request is 1123 encapsulated in this packet format, the destination address in 1124 this header is an EID. 1126 UDP: The inner UDP header, where the port assignments depend on the 1127 control packet being encapsulated. When the control packet is 1128 a Map-Request or Map-Register, the source port is selected by 1129 the ITR/PITR and the destination port is 4342. When the 1130 control packet is a Map-Reply, the source port is 4342 and the 1131 destination port is assigned from the source port of the 1132 invoking Map-Request. Port number 4341 MUST NOT be assigned to 1133 either port. The checksum field MUST be non-zero. 1135 LCM: The format is one of the control message formats described in 1136 this section. At this time, only Map-Request messages are 1137 allowed to be Control-Plane (ECM) encapsulated. In the future, 1138 PIM Join/Prune messages [RFC6831] might be allowed. 1139 Encapsulating other types of LISP control messages is for 1140 further study. When Map-Requests are sent for RLOC-Probing 1141 purposes (i.e., the probe-bit is set), they MUST NOT be sent 1142 inside Encapsulated Control Messages. 1144 6. Changing the Contents of EID-to-RLOC Mappings 1146 In the LISP architecture ITRs/PITRs use a local Map-Cache to store 1147 EID-to-RLOC mappings for forwarding. When an ETR updates a mapping a 1148 mechanism is required to inform ITRs/PITRs that are using such 1149 mappings. 1151 The LISP Data-Plane defines several mechanism to update mappings 1152 [I-D.ietf-lisp-rfc6830bis]. This document specifies the Solicit-Map 1153 Request (SMR), a Control-Plane push-based mechanism. An additional 1154 Control-Plane mechanism based on the Publish/subscribe paradigm is 1155 specified in [I-D.rodrigueznatal-lisp-pubsub]. 1157 6.1. Solicit-Map-Request (SMR) 1159 Soliciting a Map-Request is a selective way for ETRs, at the site 1160 where mappings change, to control the rate they receive requests for 1161 Map-Reply messages. SMRs are also used to tell remote ITRs to update 1162 the mappings they have cached. 1164 Since the ETRs don't keep track of remote ITRs that have cached their 1165 mappings, they do not know which ITRs need to have their mappings 1166 updated. As a result, an ETR will solicit Map-Requests (called an 1167 SMR message) from those sites to which it has been sending 1168 encapsulated data for the last minute. In particular, an ETR will 1169 send an SMR to an ITR to which it has recently sent encapsulated 1170 data. This can only occur when both ITR and ETR functionality reside 1171 in the same router. 1173 An SMR message is simply a bit set in a Map-Request message. An ITR 1174 or PITR will send a Map-Request when they receive an SMR message. 1175 Both the SMR sender and the Map-Request responder MUST rate-limit 1176 these messages. Rate-limiting can be implemented as a global rate- 1177 limiter or one rate-limiter per SMR destination. 1179 The following procedure shows how an SMR exchange occurs when a site 1180 is doing Locator-Set compaction for an EID-to-RLOC mapping: 1182 1. When the database mappings in an ETR change, the ETRs at the site 1183 begin to send Map-Requests with the SMR bit set for each Locator 1184 in each Map-Cache entry the ETR caches. 1186 2. A remote ITR that receives the SMR message will schedule sending 1187 a Map-Request message to the source locator address of the SMR 1188 message or to the mapping database system. A newly allocated 1189 random nonce is selected, and the EID-Prefix used is the one 1190 copied from the SMR message. If the source Locator is the only 1191 Locator in the cached Locator-Set, the remote ITR SHOULD send a 1192 Map-Request to the database mapping system just in case the 1193 single Locator has changed and may no longer be reachable to 1194 accept the Map-Request. 1196 3. The remote ITR MUST rate-limit the Map-Request until it gets a 1197 Map-Reply while continuing to use the cached mapping. When 1198 Map-Versioning as described in [I-D.ietf-lisp-6834bis] is used, 1199 an SMR sender can detect if an ITR is using the most up-to-date 1200 database mapping. 1202 4. The ETRs at the site with the changed mapping will reply to the 1203 Map-Request with a Map-Reply message that has a nonce from the 1204 SMR-invoked Map-Request. The Map-Reply messages SHOULD be rate- 1205 limited. This is important to avoid Map-Reply implosion. 1207 5. The ETRs at the site with the changed mapping record the fact 1208 that the site that sent the Map-Request has received the new 1209 mapping data in the Map-Cache entry for the remote site so the 1210 Locator-Status-Bits are reflective of the new mapping for packets 1211 going to the remote site. The ETR then stops sending SMR 1212 messages. 1214 For security reasons, an ITR MUST NOT process unsolicited Map- 1215 Replies. To avoid Map-Cache entry corruption by a third party, a 1216 sender of an SMR-based Map-Request MUST be verified. If an ITR 1217 receives an SMR-based Map-Request and the source is not in the 1218 Locator-Set for the stored Map-Cache entry, then the responding Map- 1219 Request MUST be sent with an EID destination to the mapping database 1220 system. Since the mapping database system is a more secure way to 1221 reach an authoritative ETR, it will deliver the Map-Request to the 1222 authoritative source of the mapping data. 1224 When an ITR receives an SMR-based Map-Request for which it does not 1225 have a cached mapping for the EID in the SMR message, it may not send 1226 an SMR-invoked Map-Request. This scenario can occur when an ETR 1227 sends SMR messages to all Locators in the Locator-Set it has stored 1228 in its Map-Cache but the remote ITRs that receive the SMR may not be 1229 sending packets to the site. There is no point in updating the ITRs 1230 until they need to send, in which case they will send Map-Requests to 1231 obtain a Map-Cache entry. 1233 7. Routing Locator Reachability 1235 This document defines several Control-Plane mechanisms for 1236 determining RLOC reachability. Please note that additional Data- 1237 Plane reachability mechanisms are defined in 1238 [I-D.ietf-lisp-rfc6830bis]. 1240 1. An ITR MAY receive an ICMP Network Unreachable or Host 1241 Unreachable message for an RLOC it is using. This indicates that 1242 the RLOC is likely down. Note that trusting ICMP messages may 1243 not be desirable, but neither is ignoring them completely. 1244 Implementations are encouraged to follow current best practices 1245 in treating these conditions [I-D.ietf-opsec-icmp-filtering]. 1247 2. When an ITR participates in the routing protocol that operates in 1248 the underlay routing system, it can determine that an RLOC is 1249 down when no Routing Information Base (RIB) entry exists that 1250 matches the RLOC IP address. 1252 3. An ITR MAY receive an ICMP Port Unreachable message from a 1253 destination host. This occurs if an ITR attempts to use 1254 interworking [RFC6832] and LISP-encapsulated data is sent to a 1255 non-LISP-capable site. 1257 4. An ITR MAY receive a Map-Reply from an ETR in response to a 1258 previously sent Map-Request. The RLOC source of the Map-Reply is 1259 likely up, since the ETR was able to send the Map-Reply to the 1260 ITR. 1262 5. An ITR/ETR pair can use the 'RLOC-Probing' mechanism described 1263 below. 1265 When ITRs receive ICMP Network Unreachable or Host Unreachable 1266 messages as a method to determine unreachability, they will refrain 1267 from using Locators that are described in Locator lists of Map- 1268 Replies. However, using this approach is unreliable because many 1269 network operators turn off generation of ICMP Destination Unreachable 1270 messages. 1272 If an ITR does receive an ICMP Network Unreachable or Host 1273 Unreachable message, it MAY originate its own ICMP Destination 1274 Unreachable message destined for the host that originated the data 1275 packet the ITR encapsulated. 1277 Also, BGP-enabled ITRs can unilaterally examine the RIB to see if a 1278 locator address from a Locator-Set in a mapping entry matches a 1279 prefix. If it does not find one and BGP is running in the Default- 1280 Free Zone (DFZ), it can decide to not use the Locator even though the 1281 Locator-Status-Bits indicate that the Locator is up. In this case, 1282 the path from the ITR to the ETR that is assigned the Locator is not 1283 available. More details are in [I-D.meyer-loc-id-implications]. 1285 Optionally, an ITR can send a Map-Request to a Locator, and if a Map- 1286 Reply is returned, reachability of the Locator has been determined. 1287 Obviously, sending such probes increases the number of control 1288 messages originated by Tunnel Routers for active flows, so Locators 1289 are assumed to be reachable when they are advertised. 1291 This assumption does create a dependency: Locator unreachability is 1292 detected by the receipt of ICMP Host Unreachable messages. When a 1293 Locator has been determined to be unreachable, it is not used for 1294 active traffic; this is the same as if it were listed in a Map-Reply 1295 with Priority 255. 1297 The ITR can test the reachability of the unreachable Locator by 1298 sending periodic Requests. Both Requests and Replies MUST be rate- 1299 limited. Locator reachability testing is never done with data 1300 packets, since that increases the risk of packet loss for end-to-end 1301 sessions. 1303 7.1. RLOC-Probing Algorithm 1305 RLOC-Probing is a method that an ITR or PITR can use to determine the 1306 reachability status of one or more Locators that it has cached in a 1307 Map-Cache entry. The probe-bit of the Map-Request and Map-Reply 1308 messages is used for RLOC-Probing. 1310 RLOC-Probing is done in the control plane on a timer basis, where an 1311 ITR or PITR will originate a Map-Request destined to a locator 1312 address from one of its own locator addresses. A Map-Request used as 1313 an RLOC-probe is NOT encapsulated and NOT sent to a Map-Server or to 1314 the mapping database system as one would when soliciting mapping 1315 data. The EID record encoded in the Map-Request is the EID-Prefix of 1316 the Map-Cache entry cached by the ITR or PITR. The ITR MAY include a 1317 mapping data record for its own database mapping information that 1318 contains the local EID-Prefixes and RLOCs for its site. RLOC-probes 1319 are sent periodically using a jittered timer interval. 1321 When an ETR receives a Map-Request message with the probe-bit set, it 1322 returns a Map-Reply with the probe-bit set. The source address of 1323 the Map-Reply is set according to the procedure described in 1324 [I-D.ietf-lisp-rfc6830bis]. The Map-Reply SHOULD contain mapping 1325 data for the EID-Prefix contained in the Map-Request. This provides 1326 the opportunity for the ITR or PITR that sent the RLOC-probe to get 1327 mapping updates if there were changes to the ETR's database mapping 1328 entries. 1330 There are advantages and disadvantages of RLOC-Probing. The greatest 1331 benefit of RLOC-Probing is that it can handle many failure scenarios 1332 allowing the ITR to determine when the path to a specific Locator is 1333 reachable or has become unreachable, thus providing a robust 1334 mechanism for switching to using another Locator from the cached 1335 Locator. RLOC-Probing can also provide rough Round-Trip Time (RTT) 1336 estimates between a pair of Locators, which can be useful for network 1337 management purposes as well as for selecting low delay paths. The 1338 major disadvantage of RLOC-Probing is in the number of control 1339 messages required and the amount of bandwidth used to obtain those 1340 benefits, especially if the requirement for failure detection times 1341 is very small. 1343 8. Interactions with Other LISP Components 1345 8.1. ITR EID-to-RLOC Mapping Resolution 1347 An ITR is configured with one or more Map-Resolver addresses. These 1348 addresses are "Locators" (or RLOCs) and MUST be routable on the 1349 underlying core network; they MUST NOT need to be resolved through 1350 LISP EID-to-RLOC mapping, as that would introduce a circular 1351 dependency. When using a Map-Resolver, an ITR does not need to 1352 connect to any other database mapping system. In particular, the ITR 1353 need not connect to the LISP-ALT infrastructure or implement the BGP 1354 and GRE protocols that it uses. 1356 An ITR sends an Encapsulated Map-Request to a configured Map-Resolver 1357 when it needs an EID-to-RLOC mapping that is not found in its local 1358 Map-Cache. Using the Map-Resolver greatly reduces both the 1359 complexity of the ITR implementation and the costs associated with 1360 its operation. 1362 In response to an Encapsulated Map-Request, the ITR can expect one of 1363 the following: 1365 o An immediate Negative Map-Reply (with action code of "Natively- 1366 Forward", 15-minute Time to Live (TTL)) from the Map-Resolver if 1367 the Map-Resolver can determine that the requested EID does not 1368 exist. The ITR saves the EID-Prefix returned in the Map-Reply in 1369 its cache, marks it as non-LISP-capable, and knows not to attempt 1370 LISP encapsulation for destinations matching it. 1372 o A Negative Map-Reply, with action code of "Natively-Forward", from 1373 a Map-Server that is authoritative for an EID-Prefix that matches 1374 the requested EID but that does not have an actively registered, 1375 more-specific ID-prefix. In this case, the requested EID is said 1376 to match a "hole" in the authoritative EID-Prefix. If the 1377 requested EID matches a more-specific EID-Prefix that has been 1378 delegated by the Map-Server but for which no ETRs are currently 1379 registered, a 1-minute TTL is returned. If the requested EID 1380 matches a non-delegated part of the authoritative EID-Prefix, then 1381 it is not a LISP EID and a 15-minute TTL is returned. See 1382 Section 8.2 for discussion of aggregate EID-Prefixes and details 1383 of Map-Server EID-Prefix matching. 1385 o A LISP Map-Reply from the ETR that owns the EID-to-RLOC mapping or 1386 possibly from a Map-Server answering on behalf of the ETR. See 1387 Section 8.4 for more details on Map-Resolver message processing. 1389 Note that an ITR MAY be configured to both use a Map-Resolver and to 1390 participate in a LISP-ALT logical network. In such a situation, the 1391 ITR SHOULD send Map-Requests through the ALT network for any EID- 1392 Prefix learned via ALT BGP. Such a configuration is expected to be 1393 very rare, since there is little benefit to using a Map-Resolver if 1394 an ITR is already using LISP-ALT. There would be, for example, no 1395 need for such an ITR to send a Map-Request to a possibly non-existent 1396 EID (and rely on Negative Map-Replies) if it can consult the ALT 1397 database to verify that an EID-Prefix is present before sending that 1398 Map-Request. 1400 8.2. EID-Prefix Configuration and ETR Registration 1402 An ETR publishes its EID-Prefixes on a Map-Server by sending LISP 1403 Map-Register messages. A Map-Register message includes 1404 authentication data, so prior to sending a Map-Register message, the 1405 ETR and Map-Server SHOULD be configured with a shared secret or other 1406 relevant authentication information. A Map-Server's configuration 1407 SHOULD also include a list of the EID-Prefixes for which each ETR is 1408 authoritative. Upon receipt of a Map-Register from an ETR, a Map- 1409 Server accepts only EID-Prefixes that are configured for that ETR. 1410 Failure to implement such a check would leave the mapping system 1411 vulnerable to trivial EID-Prefix hijacking attacks. As developers 1412 and operators gain experience with the mapping system, additional, 1413 stronger security measures MAY be added to the registration process. 1415 In addition to the set of EID-Prefixes defined for each ETR that MAY 1416 register, a Map-Server is typically also configured with one or more 1417 aggregate prefixes that define the part of the EID numbering space 1418 assigned to it. When LISP-ALT is the database in use, aggregate EID- 1419 Prefixes are implemented as discard routes and advertised into ALT 1420 BGP. The existence of aggregate EID-Prefixes in a Map-Server's 1421 database means that it MAY receive Map Requests for EID-Prefixes that 1422 match an aggregate but do not match a registered prefix; Section 8.3 1423 describes how this is handled. 1425 Map-Register messages are sent periodically from an ETR to a Map- 1426 Server with a suggested interval between messages of one minute. A 1427 Map-Server SHOULD time out and remove an ETR's registration if it has 1428 not received a valid Map-Register message within the past 1429 three minutes. When first contacting a Map-Server after restart or 1430 changes to its EID-to-RLOC database mappings, an ETR MAY initially 1431 send Map-Register messages at an increased frequency, up to one every 1432 20 seconds. This "quick registration" period is limited to 1433 five minutes in duration. 1435 An ETR MAY request that a Map-Server explicitly acknowledge receipt 1436 and processing of a Map-Register message by setting the "want-map- 1437 notify" (M-bit) flag. A Map-Server that receives a Map-Register with 1438 this flag set will respond with a Map-Notify message. Typical use of 1439 this flag by an ETR would be to set it for Map-Register messages sent 1440 during the initial "quick registration" with a Map-Server but then 1441 set it only occasionally during steady-state maintenance of its 1442 association with that Map-Server. Note that the Map-Notify message 1443 is sent to UDP destination port 4342, not to the source port 1444 specified in the original Map-Register message. 1446 Note that a one-minute minimum registration interval during 1447 maintenance of an ETR-Map-Server association places a lower bound on 1448 how quickly and how frequently a mapping database entry can be 1449 updated. This MAY have implications for what sorts of mobility can 1450 be supported directly by the mapping system; shorter registration 1451 intervals or other mechanisms might be needed to support faster 1452 mobility in some cases. For a discussion on one way that faster 1453 mobility MAY be implemented for individual devices, please see 1454 [I-D.ietf-lisp-mn]. 1456 An ETR MAY also request, by setting the "proxy Map-Reply" flag 1457 (P-bit) in the Map-Register message, that a Map-Server answer Map- 1458 Requests instead of forwarding them to the ETR. See Section 7.1 for 1459 details on how the Map-Server sets certain flags (such as those 1460 indicating whether the message is authoritative and how returned 1461 Locators SHOULD be treated) when sending a Map-Reply on behalf of an 1462 ETR. When an ETR requests proxy reply service, it SHOULD include all 1463 RLOCs for all ETRs for the EID-Prefix being registered, along with 1464 the routable flag ("R-bit") setting for each RLOC. The Map-Server 1465 includes all of this information in Map-Reply messages that it sends 1466 on behalf of the ETR. This differs from a non-proxy registration, 1467 since the latter need only provide one or more RLOCs for a Map-Server 1468 to use for forwarding Map-Requests; the registration information is 1469 not used in Map-Replies, so it being incomplete is not incorrect. 1471 An ETR that uses a Map-Server to publish its EID-to-RLOC mappings 1472 does not need to participate further in the mapping database 1473 protocol(s). When using a LISP-ALT mapping database, for example, 1474 this means that the ETR does not need to implement GRE or BGP, which 1475 greatly simplifies its configuration and reduces its cost of 1476 operation. 1478 Note that use of a Map-Server does not preclude an ETR from also 1479 connecting to the mapping database (i.e., it could also connect to 1480 the LISP-ALT network), but doing so doesn't seem particularly useful, 1481 as the whole purpose of using a Map-Server is to avoid the complexity 1482 of the mapping database protocols. 1484 8.3. Map-Server Processing 1486 Once a Map-Server has EID-Prefixes registered by its client ETRs, it 1487 can accept and process Map-Requests for them. 1489 In response to a Map-Request (received over the ALT if LISP-ALT is in 1490 use), the Map-Server first checks to see if the destination EID 1491 matches a configured EID-Prefix. If there is no match, the Map- 1492 Server returns a Negative Map-Reply with action code "Natively- 1493 Forward" and a 15-minute TTL. This MAY occur if a Map Request is 1494 received for a configured aggregate EID-Prefix for which no more- 1495 specific EID-Prefix exists; it indicates the presence of a non-LISP 1496 "hole" in the aggregate EID-Prefix. 1498 Next, the Map-Server checks to see if any ETRs have registered the 1499 matching EID-Prefix. If none are found, then the Map-Server returns 1500 a Negative Map-Reply with action code "Natively-Forward" and a 1501 1-minute TTL. 1503 If the EID-prefix is either registered or not registered to the 1504 mapping system and there is a policy in the Map-Server to have the 1505 requestor drop packets for the matching EID-prefix, then a Drop/ 1506 Policy-Denied action is returned. If the EID-prefix is registered or 1507 not registered and there is a authentication failure, then a Drop/ 1508 Authentication- failure action is returned. If either of these 1509 actions result as a temporary state in policy or authentication then 1510 a Send-Map-Request action with 1-minute TTL MAY be returned to allow 1511 the reqeustor to retry the Map-Request. 1513 If any of the registered ETRs for the EID-Prefix have requested proxy 1514 reply service, then the Map-Server answers the request instead of 1515 forwarding it. It returns a Map-Reply with the EID-Prefix, RLOCs, 1516 and other information learned through the registration process. 1518 If none of the ETRs have requested proxy reply service, then the Map- 1519 Server re-encapsulates and forwards the resulting Encapsulated Map- 1520 Request to one of the registered ETRs. It does not otherwise alter 1521 the Map-Request, so any Map-Reply sent by the ETR is returned to the 1522 RLOC in the Map-Request, not to the Map-Server. Unless also acting 1523 as a Map-Resolver, a Map-Server SHOULD never receive Map-Replies; any 1524 such messages SHOULD be discarded without response, perhaps 1525 accompanied by the logging of a diagnostic message if the rate of 1526 Map-Replies is suggestive of malicious traffic. 1528 8.4. Map-Resolver Processing 1530 Upon receipt of an Encapsulated Map-Request, a Map-Resolver 1531 decapsulates the enclosed message and then searches for the requested 1532 EID in its local database of mapping entries (statically configured 1533 or learned from associated ETRs if the Map-Resolver is also a Map- 1534 Server offering proxy reply service). If it finds a matching entry, 1535 it returns a LISP Map-Reply with the known mapping. 1537 If the Map-Resolver does not have the mapping entry and if it can 1538 determine that the EID is not in the mapping database (for example, 1539 if LISP-ALT is used, the Map-Resolver will have an ALT forwarding 1540 table that covers the full EID space), it immediately returns a 1541 negative LISP Map-Reply, with action code "Natively-Forward" and a 1542 15-minute TTL. To minimize the number of negative cache entries 1543 needed by an ITR, the Map-Resolver SHOULD return the least-specific 1544 prefix that both matches the original query and does not match any 1545 EID-Prefix known to exist in the LISP-capable infrastructure. 1547 If the Map-Resolver does not have sufficient information to know 1548 whether the EID exists, it needs to forward the Map-Request to 1549 another device that has more information about the EID being 1550 requested. To do this, it forwards the unencapsulated Map-Request, 1551 with the original ITR RLOC as the source, to the mapping database 1552 system. Using LISP-ALT, the Map-Resolver is connected to the ALT 1553 network and sends the Map-Request to the next ALT hop learned from 1554 its ALT BGP neighbors. The Map-Resolver does not send any response 1555 to the ITR; since the source RLOC is that of the ITR, the ETR or Map- 1556 Server that receives the Map-Request over the ALT and responds will 1557 do so directly to the ITR. 1559 8.4.1. Anycast Map-Resolver Operation 1561 A Map-Resolver can be set up to use "anycast", where the same address 1562 is assigned to multiple Map-Resolvers and is propagated through IGP 1563 routing, to facilitate the use of a topologically close Map-Resolver 1564 by each ITR. 1566 Note that Map-Server associations with ETRs SHOULD NOT use anycast 1567 addresses, as registrations need to be established between an ETR and 1568 a specific set of Map-Servers, each identified by a specific 1569 registration association. 1571 9. Security Considerations 1573 The 2-way LISP header nonce exchange documented in 1574 [I-D.ietf-lisp-rfc6830bis] can be used to avoid ITR spoofing attacks. 1576 To publish an authoritative EID-to-RLOC mapping with a Map-Server, an 1577 ETR includes authentication data that is a hash of the message using 1578 a pair-wise shared key. An implementation MUST support use of HMAC- 1579 SHA-1-96 [RFC2104] and SHOULD support use of HMAC-SHA-256-128 1580 [RFC6234] (SHA-256 truncated to 128 bits). 1582 As noted in Section 8.2, a Map-Server SHOULD verify that all EID- 1583 Prefixes registered by an ETR match the configuration stored on the 1584 Map-Server. 1586 The currently defined authentication mechanism for Map-Register 1587 messages does not provide protection against "replay" attacks by a 1588 "man-in-the-middle". Additional work is needed in this area. 1590 [I-D.ietf-lisp-sec] defines a proposed mechanism for providing origin 1591 authentication, integrity, anti-replay protection, and prevention of 1592 man-in-the-middle and "overclaiming" attacks on the Map-Request/Map- 1593 Reply exchange. Work is ongoing on this and other proposals for 1594 resolving these open security issues. 1596 While beyond the scope of securing an individual Map-Server or Map- 1597 Resolver, it SHOULD be noted that a BGP-based LISP-ALT network (if 1598 ALT is used as the mapping database infrastructure) can take 1599 advantage of standards work on adding security to BGP. 1601 A complete LISP threat analysis has been published in [RFC7835]. 1602 Please refer to it for more security related details. 1604 10. IANA Considerations 1606 This section provides guidance to the Internet Assigned Numbers 1607 Authority (IANA) regarding registration of values related to this 1608 LISP Control-Plane specification, in accordance with BCP 26 1609 [RFC8126]. 1611 There are three namespaces (listed in the sub-sections below) in LISP 1612 that have been registered. 1614 o LISP IANA registry allocations SHOULD NOT be made for purposes 1615 unrelated to LISP routing or transport protocols. 1617 o The following policies are used here with the meanings defined in 1618 BCP 26: "Specification Required", "IETF Review", "Experimental 1619 Use", and "First Come First Served". 1621 10.1. LISP UDP Port Numbers 1623 The IANA registry has allocated UDP port number 4342 for the LISP 1624 Control-Plane. IANA has updated the description for UDP port 4342 as 1625 follows: 1627 Keyword Port Transport Layer Description 1628 ------- ---- --------------- ----------- 1629 lisp-control 4342 udp LISP Control Packets 1631 10.2. LISP Packet Type Codes 1633 It is being requested that the IANA be authoritative for LISP Packet 1634 Type definitions and that it refers to this document as well as 1635 [RFC8113] as references. 1637 Based on deployment experience of [RFC6830], the Map-Notify-Ack 1638 message, message type 5, was added to this document. This document 1639 requests IANA to add it to the LISP Packet Type Registry. 1641 Name Number Defined in 1642 ---- ------ ----------- 1643 LISP Map-Notify-Ack 5 RFC6833bis 1645 10.3. LISP ACT and Flag Fields 1647 New ACT values can be allocated through IETF review or IESG approval. 1648 Four values have already been allocated by [RFC6830]. This 1649 specification changes the name of ACT type 3 value from "Drop" to 1650 "Drop/No-Reason" as well as adding two new ACT values, the "Drop/ 1651 Policy-Denied" (type 4) and "Drop/Authentication-Failure" (type 5). 1653 Value Action Description Reference 1654 ----- ------ ----------- --------- 1655 4 Drop/ A Packet matching this Map-Cache RFC6833bis 1656 Policy-Denied entry is dropped because the target 1657 EID is policy-denied by the xTR or 1658 the mapping system. 1660 5 Drop/ A Packet matching this Map-Cache RFC6833bis 1661 Auth-Failure entry is dropped because the 1662 Map-Request for target EID fails an 1663 authentication check by the xTR or 1664 the mapping system. 1666 In addition, LISP has a number of flag fields and reserved fields, 1667 such as the LISP header flags field [I-D.ietf-lisp-rfc6830bis]. New 1668 bits for flags in these fields can be implemented after IETF review 1669 or IESG approval, but these need not be managed by IANA. 1671 10.4. LISP Address Type Codes 1673 LISP Canonical Address Format (LCAF) [RFC8060] is an 8-bit field that 1674 defines LISP-specific encodings for AFI value 16387. LCAF encodings 1675 are used for specific use-cases where different address types for 1676 EID-records and RLOC-records are required. 1678 The IANA registry "LISP Canonical Address Format (LCAF) Types" is 1679 used for LCAF types, the registry for LCAF types use the 1680 Specification Required policy [RFC8126]. Initial values for the 1681 registry as well as further information can be found in [RFC8060]. 1683 Therefore, there is no longer a need for the "LISP Address Type 1684 Codes" registry requested by [RFC6830]. This document requests to 1685 remove it. 1687 10.5. LISP Algorithm ID Numbers 1689 In [RFC6830], a request for a "LISP Key ID Numbers" registry was 1690 submitted. This document renames the registry to "LISP Algorithm ID 1691 Numbers" and requests the IANA to make the name change. 1693 The following Algorithm ID values are defined by this specification 1694 as used in any packet type that references a 'Algorithm ID' field: 1696 Name Number Defined in 1697 ----------------------------------------------- 1698 None 0 RFC6833bis 1699 HMAC-SHA-1-96 1 [RFC2404] 1700 HMAC-SHA-256-128 2 [RFC4868] 1702 Number values are in the range of 0 to 255. The allocation of values 1703 is on a first come first served basis. 1705 11. References 1707 11.1. Normative References 1709 [I-D.ietf-lisp-6834bis] 1710 Iannone, L., Saucez, D., and O. Bonaventure, "Locator/ID 1711 Separation Protocol (LISP) Map-Versioning", draft-ietf- 1712 lisp-6834bis-00 (work in progress), July 2018. 1714 [I-D.ietf-lisp-rfc6830bis] 1715 Farinacci, D., Fuller, V., Meyer, D., Lewis, D., and A. 1716 Cabellos-Aparicio, "The Locator/ID Separation Protocol 1717 (LISP)", draft-ietf-lisp-rfc6830bis-14 (work in progress), 1718 July 2018. 1720 [RFC2404] Madson, C. and R. Glenn, "The Use of HMAC-SHA-1-96 within 1721 ESP and AH", RFC 2404, DOI 10.17487/RFC2404, November 1722 1998, . 1724 [RFC4086] Eastlake 3rd, D., Schiller, J., and S. Crocker, 1725 "Randomness Requirements for Security", BCP 106, RFC 4086, 1726 DOI 10.17487/RFC4086, June 2005, 1727 . 1729 [RFC4868] Kelly, S. and S. Frankel, "Using HMAC-SHA-256, HMAC-SHA- 1730 384, and HMAC-SHA-512 with IPsec", RFC 4868, 1731 DOI 10.17487/RFC4868, May 2007, 1732 . 1734 11.2. Informative References 1736 [AFI] IANA, "Address Family Identifier (AFIs)", ADDRESS FAMILY 1737 NUMBERS http://www.iana.org/assignments/address-family- 1738 numbers/address-family-numbers.xhtml?, Febuary 2007. 1740 [I-D.ermagan-lisp-nat-traversal] 1741 Ermagan, V., Farinacci, D., Lewis, D., Skriver, J., Maino, 1742 F., and C. White, "NAT traversal for LISP", draft-ermagan- 1743 lisp-nat-traversal-14 (work in progress), April 2018. 1745 [I-D.herbert-intarea-ila] 1746 Herbert, T. and P. Lapukhov, "Identifier-locator 1747 addressing for IPv6", draft-herbert-intarea-ila-01 (work 1748 in progress), March 2018. 1750 [I-D.ietf-lisp-eid-mobility] 1751 Portoles-Comeras, M., Ashtaputre, V., Moreno, V., Maino, 1752 F., and D. Farinacci, "LISP L2/L3 EID Mobility Using a 1753 Unified Control Plane", draft-ietf-lisp-eid-mobility-02 1754 (work in progress), May 2018. 1756 [I-D.ietf-lisp-introduction] 1757 Cabellos-Aparicio, A. and D. Saucez, "An Architectural 1758 Introduction to the Locator/ID Separation Protocol 1759 (LISP)", draft-ietf-lisp-introduction-13 (work in 1760 progress), April 2015. 1762 [I-D.ietf-lisp-mn] 1763 Farinacci, D., Lewis, D., Meyer, D., and C. White, "LISP 1764 Mobile Node", draft-ietf-lisp-mn-02 (work in progress), 1765 April 2018. 1767 [I-D.ietf-lisp-sec] 1768 Maino, F., Ermagan, V., Cabellos-Aparicio, A., and D. 1769 Saucez, "LISP-Security (LISP-SEC)", draft-ietf-lisp-sec-15 1770 (work in progress), April 2018. 1772 [I-D.ietf-opsec-icmp-filtering] 1773 Gont, F., Gont, G., and C. Pignataro, "Recommendations for 1774 filtering ICMP messages", draft-ietf-opsec-icmp- 1775 filtering-04 (work in progress), July 2013. 1777 [I-D.lewis-lisp-gpe] 1778 Lewis, D., Lemon, J., Agarwal, P., Kreeger, L., Quinn, P., 1779 Smith, M., Yadav, N., and F. Maino, "LISP Generic Protocol 1780 Extension", draft-lewis-lisp-gpe-04 (work in progress), 1781 December 2017. 1783 [I-D.meyer-loc-id-implications] 1784 Meyer, D. and D. Lewis, "Architectural Implications of 1785 Locator/ID Separation", draft-meyer-loc-id-implications-01 1786 (work in progress), January 2009. 1788 [I-D.quinn-vxlan-gpe] 1789 Quinn, P., Manur, R., Kreeger, L., Lewis, D., Maino, F., 1790 Smith, M., Agarwal, P., Yong, L., Xu, X., Elzur, U., Garg, 1791 P., and D. Melman, "Generic Protocol Extension for VXLAN", 1792 draft-quinn-vxlan-gpe-04 (work in progress), February 1793 2015. 1795 [I-D.rodrigueznatal-lisp-oam] 1796 Rodriguez-Natal, A., Cabellos-Aparicio, A., Portoles- 1797 Comeras, M., Kowal, M., Lewis, D., and F. Maino, "LISP-OAM 1798 (Operations, Administration and Management): Use cases and 1799 requirements", draft-rodrigueznatal-lisp-oam-08 (work in 1800 progress), June 2018. 1802 [I-D.rodrigueznatal-lisp-pubsub] 1803 Rodriguez-Natal, A., Ermagan, V., Leong, J., Maino, F., 1804 Cabellos-Aparicio, A., Barkai, S., Farinacci, D., 1805 Boucadair, M., Jacquenet, C., and S. Secci, "Publish/ 1806 Subscribe Functionality for LISP", draft-rodrigueznatal- 1807 lisp-pubsub-02 (work in progress), March 2018. 1809 [RFC1035] Mockapetris, P., "Domain names - implementation and 1810 specification", STD 13, RFC 1035, DOI 10.17487/RFC1035, 1811 November 1987, . 1813 [RFC1071] Braden, R., Borman, D., and C. Partridge, "Computing the 1814 Internet checksum", RFC 1071, DOI 10.17487/RFC1071, 1815 September 1988, . 1817 [RFC2104] Krawczyk, H., Bellare, M., and R. Canetti, "HMAC: Keyed- 1818 Hashing for Message Authentication", RFC 2104, 1819 DOI 10.17487/RFC2104, February 1997, 1820 . 1822 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 1823 Requirement Levels", BCP 14, RFC 2119, 1824 DOI 10.17487/RFC2119, March 1997, 1825 . 1827 [RFC6234] Eastlake 3rd, D. and T. Hansen, "US Secure Hash Algorithms 1828 (SHA and SHA-based HMAC and HKDF)", RFC 6234, 1829 DOI 10.17487/RFC6234, May 2011, 1830 . 1832 [RFC6830] Farinacci, D., Fuller, V., Meyer, D., and D. Lewis, "The 1833 Locator/ID Separation Protocol (LISP)", RFC 6830, 1834 DOI 10.17487/RFC6830, January 2013, 1835 . 1837 [RFC6831] Farinacci, D., Meyer, D., Zwiebel, J., and S. Venaas, "The 1838 Locator/ID Separation Protocol (LISP) for Multicast 1839 Environments", RFC 6831, DOI 10.17487/RFC6831, January 1840 2013, . 1842 [RFC6832] Lewis, D., Meyer, D., Farinacci, D., and V. Fuller, 1843 "Interworking between Locator/ID Separation Protocol 1844 (LISP) and Non-LISP Sites", RFC 6832, 1845 DOI 10.17487/RFC6832, January 2013, 1846 . 1848 [RFC6836] Fuller, V., Farinacci, D., Meyer, D., and D. Lewis, 1849 "Locator/ID Separation Protocol Alternative Logical 1850 Topology (LISP+ALT)", RFC 6836, DOI 10.17487/RFC6836, 1851 January 2013, . 1853 [RFC6837] Lear, E., "NERD: A Not-so-novel Endpoint ID (EID) to 1854 Routing Locator (RLOC) Database", RFC 6837, 1855 DOI 10.17487/RFC6837, January 2013, 1856 . 1858 [RFC7215] Jakab, L., Cabellos-Aparicio, A., Coras, F., Domingo- 1859 Pascual, J., and D. Lewis, "Locator/Identifier Separation 1860 Protocol (LISP) Network Element Deployment 1861 Considerations", RFC 7215, DOI 10.17487/RFC7215, April 1862 2014, . 1864 [RFC7348] Mahalingam, M., Dutt, D., Duda, K., Agarwal, P., Kreeger, 1865 L., Sridhar, T., Bursell, M., and C. Wright, "Virtual 1866 eXtensible Local Area Network (VXLAN): A Framework for 1867 Overlaying Virtualized Layer 2 Networks over Layer 3 1868 Networks", RFC 7348, DOI 10.17487/RFC7348, August 2014, 1869 . 1871 [RFC7835] Saucez, D., Iannone, L., and O. Bonaventure, "Locator/ID 1872 Separation Protocol (LISP) Threat Analysis", RFC 7835, 1873 DOI 10.17487/RFC7835, April 2016, 1874 . 1876 [RFC8060] Farinacci, D., Meyer, D., and J. Snijders, "LISP Canonical 1877 Address Format (LCAF)", RFC 8060, DOI 10.17487/RFC8060, 1878 February 2017, . 1880 [RFC8111] Fuller, V., Lewis, D., Ermagan, V., Jain, A., and A. 1881 Smirnov, "Locator/ID Separation Protocol Delegated 1882 Database Tree (LISP-DDT)", RFC 8111, DOI 10.17487/RFC8111, 1883 May 2017, . 1885 [RFC8113] Boucadair, M. and C. Jacquenet, "Locator/ID Separation 1886 Protocol (LISP): Shared Extension Message & IANA Registry 1887 for Packet Type Allocations", RFC 8113, 1888 DOI 10.17487/RFC8113, March 2017, 1889 . 1891 [RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for 1892 Writing an IANA Considerations Section in RFCs", BCP 26, 1893 RFC 8126, DOI 10.17487/RFC8126, June 2017, 1894 . 1896 [RFC8378] Moreno, V. and D. Farinacci, "Signal-Free Locator/ID 1897 Separation Protocol (LISP) Multicast", RFC 8378, 1898 DOI 10.17487/RFC8378, May 2018, 1899 . 1901 Appendix A. Acknowledgments 1903 The authors would like to thank Greg Schudel, Darrel Lewis, John 1904 Zwiebel, Andrew Partan, Dave Meyer, Isidor Kouvelas, Jesper Skriver, 1905 Fabio Maino, and members of the lisp@ietf.org mailing list for their 1906 feedback and helpful suggestions. 1908 Special thanks are due to Noel Chiappa for his extensive work and 1909 thought about caching in Map-Resolvers. 1911 Appendix B. Document Change Log 1913 [RFC Editor: Please delete this section on publication as RFC.] 1915 B.1. Changes to draft-ietf-lisp-rfc6833bis-12 1917 o Posted late July 2018. 1919 o Moved RFC6830bis and RFC6834bis to Normative References. 1921 B.2. Changes to draft-ietf-lisp-rfc6833bis-11 1923 o Posted July 2018. 1925 o Fixed Luigi editorial comments to ready draft for RFC status and 1926 ran through IDNITs again. 1928 B.3. Changes to draft-ietf-lisp-rfc6833bis-10 1930 o Posted after LISP WG at IETF week March. 1932 o Move AD field encoding after S-bit in the ECM packet format 1933 description section. 1935 o Say more about when the new Drop actions should be sent. 1937 B.4. Changes to draft-ietf-lisp-rfc6833bis-09 1939 o Posted March IETF week 2018. 1941 o Fixed editorial comments submitted by document shepherd Luigi 1942 Iannone. 1944 B.5. Changes to draft-ietf-lisp-rfc6833bis-08 1946 o Posted March 2018. 1948 o Added RLOC-probing algorithm. 1950 o Added Solicit-Map Request algorithm. 1952 o Added several mechanisms (from 6830bis) regarding Routing Locator 1953 Reachability. 1955 o Added port 4342 to IANA Considerations section. 1957 B.6. Changes to draft-ietf-lisp-rfc6833bis-07 1959 o Posted December 2017. 1961 o Make it more clear in a couple of places that RLOCs are used to 1962 locate ETRs more so than for Map-Server Map-Request forwarding. 1964 o Make it clear that "encapsualted" for a control message is an ECM 1965 based message. 1967 o Make it more clear what messages use source-port 4342 and which 1968 ones use destinatino-port 4342. 1970 o Don't make DDT references when the mapping transport system can be 1971 of any type and the referneced text is general to it. 1973 o Generalize text when referring to the format of an EID-prefix. 1974 Can use othe AFIs then IPv4 and IPv6. 1976 o Many editorial changes to clarify text. 1978 o Changed some "must", "should", and "may" to capitalized. 1980 o Added definitions for Map-Request and Map-Reply messages. 1982 o Ran document through IDNITs. 1984 B.7. Changes to draft-ietf-lisp-rfc6833bis-06 1986 o Posted October 2017. 1988 o Spec the I-bit to include the xTR-ID in a Map-Request message to 1989 be consistent with the Map-Register message and to anticipate the 1990 introduction of pubsub functionality to allow Map-Requests to 1991 subscribe to RLOC-set changes. 1993 o Updated references for individual submissions that became working 1994 group documents. 1996 o Updated references for working group documents that became RFCs. 1998 B.8. Changes to draft-ietf-lisp-rfc6833bis-05 2000 o Posted May 2017. 2002 o Update IANA Considerations section based on new requests from this 2003 document and changes from what was requested in [RFC6830]. 2005 B.9. Changes to draft-ietf-lisp-rfc6833bis-04 2007 o Posted May 2017. 2009 o Clarify how the Key-ID field is used in Map-Register and Map- 2010 Notify messages. Break the 16-bit field into a 8-bit Key-ID field 2011 and a 8-bit Algorithm-ID field. 2013 o Move the Control-Plane codepoints from the IANA Considerations 2014 section of RFC6830bis to the IANA Considerations section of this 2015 document. 2017 o In the "LISP Control Packet Type Allocations" section, indicate 2018 how message Types are IANA allocated and how experimental RFC8113 2019 sub-types should be requested. 2021 B.10. Changes to draft-ietf-lisp-rfc6833bis-03 2023 o Posted April 2017. 2025 o Add types 9-14 and specify they are not assigned. 2027 o Add the "LISP Shared Extension Message" type and point to RFC8113. 2029 B.11. Changes to draft-ietf-lisp-rfc6833bis-02 2031 o Posted April 2017. 2033 o Clarify that the LISP Control-Plane document defines how the LISP 2034 Data-Plane uses Map-Requests with either the SMR-bit set or the 2035 P-bit set supporting mapping updates and RLOC-probing. Indicating 2036 that other Data-Planes can use the same mechanisms or their own 2037 defined mechanisms to achieve the same functionality. 2039 B.12. Changes to draft-ietf-lisp-rfc6833bis-01 2041 o Posted March 2017. 2043 o Include references to new RFCs published. 2045 o Remove references to self. 2047 o Change references from RFC6830 to RFC6830bis. 2049 o Add two new action/reasons to a Map-Reply has posted to the LISP 2050 WG mailing list. 2052 o In intro section, add refernece to I-D.ietf-lisp-introduction. 2054 o Removed Open Issues section and references to "experimental". 2056 B.13. Changes to draft-ietf-lisp-rfc6833bis-00 2058 o Posted December 2016. 2060 o Created working group document from draft-farinacci-lisp 2061 -rfc6833-00 individual submission. No other changes made. 2063 B.14. Changes to draft-farinacci-lisp-rfc6833bis-00 2065 o Posted November 2016. 2067 o This is the initial draft to turn RFC 6833 into RFC 6833bis. 2069 o The document name has changed from the "Locator/ID Separation 2070 Protocol (LISP) Map-Server Interface" to the "Locator/ID 2071 Separation Protocol (LISP) Control-Plane". 2073 o The fundamental change was to move the Control-Plane messages from 2074 RFC 6830 to this document in an effort so any IETF developed or 2075 industry created Data-Plane could use the LISP mapping system and 2076 Control-Plane. 2078 o Update Control-Plane messages to incorporate what has been 2079 implemented in products during the early phase of LISP development 2080 but wasn't able to make it into RFC6830 and RFC6833 to make the 2081 Experimental RFC deadline. 2083 o Indicate there may be nodes in the mapping system that are not MRs 2084 or MSs, that is a ALT-node or a DDT-node. 2086 o Include LISP-DDT in Map-Resolver section and explain how they 2087 maintain a referral-cache. 2089 o Removed open issue about additional state in Map-Servers. With 2090 [RFC8111], Map-Servers have the same registration state and can 2091 give Map-Resolvers complete information in ms-ack Map-Referral 2092 messages. 2094 o Make reference to the LISP Threats Analysis RFC [RFC7835]. 2096 Authors' Addresses 2098 Vince Fuller 2099 Cisco Systems 2101 EMail: vaf@vaf.net 2103 Dino Farinacci 2104 Cisco Systems 2106 EMail: farinacci@gmail.com 2108 Albert Cabellos 2109 UPC/BarcelonaTech 2110 Campus Nord, C. Jordi Girona 1-3 2111 Barcelona, Catalunya 2112 Spain 2114 EMail: acabello@ac.upc.edu