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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 Intended status: Standards Track Cisco Systems 5 Expires: September 19, 2018 A. Cabellos (Ed.) 6 UPC/BarcelonaTech 7 March 18, 2018 9 Locator/ID Separation Protocol (LISP) Control-Plane 10 draft-ietf-lisp-rfc6833bis-09 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 Status of This Memo 32 This Internet-Draft is submitted in full conformance with the 33 provisions of BCP 78 and BCP 79. 35 Internet-Drafts are working documents of the Internet Engineering 36 Task Force (IETF). Note that other groups may also distribute 37 working documents as Internet-Drafts. The list of current Internet- 38 Drafts is at https://datatracker.ietf.org/drafts/current/. 40 Internet-Drafts are draft documents valid for a maximum of six months 41 and may be updated, replaced, or obsoleted by other documents at any 42 time. It is inappropriate to use Internet-Drafts as reference 43 material or to cite them other than as "work in progress." 45 This Internet-Draft will expire on September 19, 2018. 47 Copyright Notice 49 Copyright (c) 2018 IETF Trust and the persons identified as the 50 document authors. All rights reserved. 52 This document is subject to BCP 78 and the IETF Trust's Legal 53 Provisions Relating to IETF Documents 54 (https://trustee.ietf.org/license-info) in effect on the date of 55 publication of this document. Please review these documents 56 carefully, as they describe your rights and restrictions with respect 57 to this document. Code Components extracted from this document must 58 include Simplified BSD License text as described in Section 4.e of 59 the Trust Legal Provisions and are provided without warranty as 60 described in the Simplified BSD License. 62 Table of Contents 64 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 65 2. Requirements Notation . . . . . . . . . . . . . . . . . . . . 4 66 3. Definition of Terms . . . . . . . . . . . . . . . . . . . . . 4 67 4. Basic Overview . . . . . . . . . . . . . . . . . . . . . . . 5 68 5. LISP IPv4 and IPv6 Control-Plane Packet Formats . . . . . . . 7 69 5.1. LISP Control Packet Type Allocations . . . . . . . . . . 9 70 5.2. Map-Request Message Format . . . . . . . . . . . . . . . 10 71 5.3. EID-to-RLOC UDP Map-Request Message . . . . . . . . . . . 13 72 5.4. Map-Reply Message Format . . . . . . . . . . . . . . . . 15 73 5.5. EID-to-RLOC UDP Map-Reply Message . . . . . . . . . . . . 19 74 5.6. Map-Register Message Format . . . . . . . . . . . . . . . 22 75 5.7. Map-Notify/Map-Notify-Ack Message Format . . . . . . . . 25 76 5.8. Encapsulated Control Message Format . . . . . . . . . . . 26 77 6. Changing the Contents of EID-to-RLOC Mappings . . . . . . . . 28 78 6.1. Solicit-Map-Request (SMR) . . . . . . . . . . . . . . . . 28 79 7. Routing Locator Reachability . . . . . . . . . . . . . . . . 29 80 7.1. RLOC-Probing Algorithm . . . . . . . . . . . . . . . . . 31 81 8. Interactions with Other LISP Components . . . . . . . . . . . 32 82 8.1. ITR EID-to-RLOC Mapping Resolution . . . . . . . . . . . 32 83 8.2. EID-Prefix Configuration and ETR Registration . . . . . . 33 84 8.3. Map-Server Processing . . . . . . . . . . . . . . . . . . 35 85 8.4. Map-Resolver Processing . . . . . . . . . . . . . . . . . 35 86 8.4.1. Anycast Map-Resolver Operation . . . . . . . . . . . 36 87 9. Security Considerations . . . . . . . . . . . . . . . . . . . 36 88 10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 37 89 10.1. LISP UDP Port Numbers . . . . . . . . . . . . . . . . . 37 90 10.2. LISP Packet Type Codes . . . . . . . . . . . . . . . . . 38 91 10.3. LISP ACT and Flag Fields . . . . . . . . . . . . . . . . 38 92 10.4. LISP Address Type Codes . . . . . . . . . . . . . . . . 38 93 10.5. LISP Algorithm ID Numbers . . . . . . . . . . . . . . . 39 94 11. References . . . . . . . . . . . . . . . . . . . . . . . . . 39 95 11.1. Normative References . . . . . . . . . . . . . . . . . . 39 96 11.2. Informative References . . . . . . . . . . . . . . . . . 41 97 Appendix A. Acknowledgments . . . . . . . . . . . . . . . . . . 44 98 Appendix B. Document Change Log . . . . . . . . . . . . . . . . 44 99 B.1. Changes to draft-ietf-lisp-rfc6833bis-09 . . . . . . . . 44 100 B.2. Changes to draft-ietf-lisp-rfc6833bis-08 . . . . . . . . 44 101 B.3. Changes to draft-ietf-lisp-rfc6833bis-07 . . . . . . . . 44 102 B.4. Changes to draft-ietf-lisp-rfc6833bis-06 . . . . . . . . 45 103 B.5. Changes to draft-ietf-lisp-rfc6833bis-05 . . . . . . . . 45 104 B.6. Changes to draft-ietf-lisp-rfc6833bis-04 . . . . . . . . 45 105 B.7. Changes to draft-ietf-lisp-rfc6833bis-03 . . . . . . . . 46 106 B.8. Changes to draft-ietf-lisp-rfc6833bis-02 . . . . . . . . 46 107 B.9. Changes to draft-ietf-lisp-rfc6833bis-01 . . . . . . . . 46 108 B.10. Changes to draft-ietf-lisp-rfc6833bis-00 . . . . . . . . 46 109 B.11. Changes to draft-farinacci-lisp-rfc6833bis-00 . . . . . . 47 110 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 47 112 1. Introduction 114 The Locator/ID Separation Protocol [I-D.ietf-lisp-introduction] and 115 [I-D.ietf-lisp-rfc6830bis] specifies an architecture and mechanism 116 for dynamic tunnelling by logically separating the addresses 117 currently used by IP in two separate name spaces: Endpoint IDs 118 (EIDs), used within sites; and Routing Locators (RLOCs), used on the 119 transit networks that make up the Internet infrastructure. To 120 achieve this separation, LISP defines protocol mechanisms for mapping 121 from EIDs to RLOCs. In addition, LISP assumes the existence of a 122 database to store and propagate those mappings globally. Several 123 such databases have been proposed; among them are the Content 124 distribution Overlay Network Service for LISP-NERD (a Not-so-novel 125 EID-to-RLOC Database) [RFC6837], LISP Alternative Logical Topology 126 (LISP-ALT) [RFC6836], and LISP Delegated Database Tree (LISP-DDT) 127 [RFC8111]. 129 The LISP Mapping Service defines two new types of LISP-speaking 130 devices: the Map-Resolver, which accepts Map-Requests from an Ingress 131 Tunnel Router (ITR) and "resolves" the EID-to-RLOC mapping using a 132 mapping database; and the Map-Server, which learns authoritative EID- 133 to-RLOC mappings from an Egress Tunnel Router (ETR) and publishes 134 them in a database. 136 This LISP Control-Plane Mapping Service can be used by many different 137 encapsulation-based or translation-based Data-Planes which include 138 but are not limited to the ones defined in LISP RFC 6830bis 139 [I-D.ietf-lisp-rfc6830bis], LISP-GPE [I-D.lewis-lisp-gpe], VXLAN 140 [RFC7348], VXLAN-GPE [I-D.quinn-vxlan-gpe], and ILA 141 [I-D.herbert-intarea-ila]. 143 Conceptually, LISP Map-Servers share some of the same basic 144 configuration and maintenance properties as Domain Name System (DNS) 145 [RFC1035] servers; likewise, Map-Resolvers are conceptually similar 146 to DNS caching resolvers. With this in mind, this specification 147 borrows familiar terminology (resolver and server) from the DNS 148 specifications. 150 Note that while this document assumes a LISP-ALT database mapping 151 infrastructure to illustrate certain aspects of Map-Server and Map- 152 Resolver operation, the Mapping Service interface can (and likely 153 will) be used by ITRs and ETRs to access other mapping database 154 systems as the LISP infrastructure evolves. 156 The LISP Mapping Service is an important component of the LISP 157 toolset. Issues and concerns about the deployment of LISP for 158 Internet traffic are discussed in [I-D.ietf-lisp-rfc6830bis], 159 [RFC7215], and [LISP-OAM]. 161 2. Requirements Notation 163 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 164 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 165 document are to be interpreted as described in [RFC2119]. 167 3. Definition of Terms 169 Map-Server: A network infrastructure component that learns of EID- 170 Prefix mapping entries from an ETR, via the registration mechanism 171 described below, or some other authoritative source if one exists. 172 A Map-Server publishes these EID-Prefixes in a mapping database. 174 Map-Request: A LISP Map-Request is a Control-Plane message to query 175 the mapping system to resolve an EID. A LISP Map-Request can also 176 be sent to an RLOC to test for reachability and to exchange 177 security keys between an encapsulator and a decapsulator. This 178 type of Map-Request is also known as an RLOC-Probe Request. 180 Map-Reply: A LISP Map-Reply is a Control-Plane message returned in 181 response to a Map-Request sent to the mapping system when 182 resolving an EID. A LISP Map-Reply can also be returned by a 183 decapsulator in response to a Map-Request sent by an encapsulator 184 to test for reachability. This type of Map-Reply is known as a 185 RLOC-Probe Reply. 187 Encapsulated Map-Request: A LISP Map-Request carried within an 188 Encapsulated Control Message (ECM), which has an additional LISP 189 header prepended. Sent to UDP destination port 4342. The "outer" 190 addresses are routable IP addresses, also known as RLOCs. Used by 191 an ITR when sending to a Map-Resolver and by a Map-Server when 192 forwarding a Map-Request to an ETR. 194 Map-Resolver: A network infrastructure component that accepts LISP 195 Encapsulated (ECM) Map-Requests, typically from an ITR, and 196 determines whether or not the destination IP address is part of 197 the EID namespace; if it is not, a Negative Map-Reply is returned. 198 Otherwise, the Map-Resolver finds the appropriate EID-to-RLOC 199 mapping by consulting a mapping database system. 201 Negative Map-Reply: A LISP Map-Reply that contains an empty 202 Locator-Set. Returned in response to a Map-Request if the 203 destination EID does not exist in the mapping database. 204 Typically, this means that the "EID" being requested is an IP 205 address connected to a non-LISP site. 207 Map-Register message: A LISP message sent by an ETR to a Map-Server 208 to register its associated EID-Prefixes. In addition to the set 209 of EID-Prefixes to register, the message includes one or more 210 RLOCs to reach ETR(s). The Map-Server uses these RLOCs when 211 forwarding Map-Requests (re-formatted as Encapsulated Map- 212 Requests). An ETR MAY request that the Map-Server answer Map- 213 Requests on its behalf by setting the "proxy Map-Reply" flag 214 (P-bit) in the message. 216 Map-Notify message: A LISP message sent by a Map-Server to an ETR 217 to confirm that a Map-Register has been received and processed. 218 An ETR requests that a Map-Notify be returned by setting the 219 "want-map-notify" flag (M-bit) in the Map-Register message. 220 Unlike a Map-Reply, a Map-Notify uses UDP port 4342 for both 221 source and destination. Map-Notify messages are also sent to ITRs 222 by Map-Servers when there are RLOC-set changes. 224 For definitions of other terms, notably Ingress Tunnel Router (ITR), 225 Egress Tunnel Router (ETR), and Re-encapsulating Tunnel Router (RTR), 226 refer to the LISP Data-Plane specification 227 [I-D.ietf-lisp-rfc6830bis]. 229 4. Basic Overview 231 A Map-Server is a device that publishes EID-Prefixes in a LISP 232 mapping database on behalf of a set of ETRs. When it receives a Map 233 Request (typically from an ITR), it consults the mapping database to 234 find an ETR that can answer with the set of RLOCs for an EID-Prefix. 235 To publish its EID-Prefixes, an ETR periodically sends Map-Register 236 messages to the Map-Server. A Map-Register message contains a list 237 of EID-Prefixes plus a set of RLOCs that can be used to reach the 238 ETRs. 240 When LISP-ALT [RFC6836] is used as the mapping database, a Map-Server 241 connects to the ALT network and acts as a "last-hop" ALT-Router. 242 Intermediate ALT-Routers forward Map-Requests to the Map-Server that 243 advertises a particular EID-Prefix, and the Map-Server forwards them 244 to the owning ETR, which responds with Map-Reply messages. 246 When LISP-DDT [RFC8111] is used as the mapping database, a Map-Server 247 sends the final Map-Referral messages from the Delegated Database 248 Tree. 250 A Map-Resolver receives Encapsulated Map-Requests from its client 251 ITRs and uses a mapping database system to find the appropriate ETR 252 to answer those requests. On a LISP-ALT network, a Map-Resolver acts 253 as a "first-hop" ALT-Router. It has Generic Routing Encapsulation 254 (GRE) tunnels configured to other ALT-Routers and uses BGP to learn 255 paths to ETRs for different prefixes in the LISP-ALT database. The 256 Map-Resolver uses this path information to forward Map-Requests over 257 the ALT to the correct ETRs. On a LISP-DDT network [RFC8111], a Map- 258 Resolver maintains a referral-cache and acts as a "first-hop" DDT- 259 node. The Map-Resolver uses the referral information to forward Map- 260 Requests. 262 Note that while it is conceivable that a Map-Resolver could cache 263 responses to improve performance, issues surrounding cache management 264 will need to be resolved so that doing so will be reliable and 265 practical. As initially deployed, Map-Resolvers will operate only in 266 a non-caching mode, decapsulating and forwarding Encapsulated Map 267 Requests received from ITRs. Any specification of caching 268 functionality is out of scope for this document. 270 Note that a single device can implement the functions of both a Map- 271 Server and a Map-Resolver, and in many cases the functions will be 272 co-located in that way. Also, there can be ALT-only nodes and DDT- 273 only nodes, when LISP-ALT and LISP-DDT are used, respectively, to 274 connecting Map-Resolvers and Map-Servers together to make up the 275 Mapping System. 277 5. LISP IPv4 and IPv6 Control-Plane Packet Formats 279 The following UDP packet formats are used by the LISP control plane. 281 0 1 2 3 282 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 1 283 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 284 |Version| IHL |Type of Service| Total Length | 285 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 286 | Identification |Flags| Fragment Offset | 287 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 288 | Time to Live | Protocol = 17 | Header Checksum | 289 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 290 | Source Routing Locator | 291 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 292 | Destination Routing Locator | 293 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 294 / | Source Port | Dest Port | 295 UDP +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 296 \ | UDP Length | UDP Checksum | 297 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 298 | | 299 | LISP Message | 300 | | 301 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 303 0 1 2 3 304 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 1 305 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 306 |Version| Traffic Class | Flow Label | 307 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 308 | Payload Length | Next Header=17| Hop Limit | 309 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 310 | | 311 + + 312 | | 313 + Source Routing Locator + 314 | | 315 + + 316 | | 317 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 318 | | 319 + + 320 | | 321 + Destination Routing Locator + 322 | | 323 + + 324 | | 325 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 326 / | Source Port | Dest Port | 327 UDP +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 328 \ | UDP Length | UDP Checksum | 329 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 330 | | 331 | LISP Message | 332 | | 333 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 335 When a UDP Map-Request, Map-Register, or Map-Notify (when used as a 336 notification message) are sent, the UDP source port is chosen by the 337 sender and the destination UDP port number is set to 4342. When a 338 UDP Map-Reply Map-Notify (when used as an acknowledgement to a Map- 339 Register), or Map-Notify-Ack are sent, the source UDP port number is 340 set to 4342 and the destination UDP port number is copied from the 341 source port of either the Map-Request or the invoking data packet. 342 Implementations MUST be prepared to accept packets when either the 343 source port or destination UDP port is set to 4342 due to NATs 344 changing port number values. 346 The 'UDP Length' field will reflect the length of the UDP header and 347 the LISP Message payload. 349 The UDP checksum is computed and set to non-zero for all messages 350 sent to or from port 4342. It MUST be checked on receipt, and if the 351 checksum fails, the control message MUST be dropped [RFC1071]. 353 The format of control messages includes the UDP header so the 354 checksum and length fields can be used to protect and delimit message 355 boundaries. 357 5.1. LISP Control Packet Type Allocations 359 This section defines the LISP control message formats and summarizes 360 for IANA the LISP Type codes assigned by this document. For 361 completeness, this document references the LISP Shared Extension 362 Message assigned by [RFC8113]. Message type definitions are: 364 Reserved: 0 b'0000' 365 LISP Map-Request: 1 b'0001' 366 LISP Map-Reply: 2 b'0010' 367 LISP Map-Register: 3 b'0011' 368 LISP Map-Notify: 4 b'0100' 369 LISP Map-Notify-Ack: 5 b'0101' 370 LISP Map-Referral: 6 b'0110' 371 LISP Encapsulated Control Message: 8 b'1000' 372 Not Assigned 9-14 b'1001'- b'1110' 373 LISP Shared Extension Message: 15 b'1111' [RFC8113] 375 Values in the "Not Assigned" range can be assigned according to 376 procedures in [RFC8126]. Documents that request for a new LISP 377 packet type MAY indicate a preferred value. 379 Protocol designers experimenting with new message formats SHOULD use 380 the LISP Shared Extension Message Type and request a [RFC8113] sub- 381 type assignment. 383 All LISP Control-Plane messages use Address Family Identifiers (AFI) 384 [AFI] or LISP Canonical Address Format (LCAF) [RFC8060] formats to 385 encode either fixed or variable length addresses. This includes 386 explicit fields in each control message or part of EID-records or 387 RLOC-records in commonly formatted messages. 389 The LISP control-plane describes how other data-planes can encode 390 messages to support the SMR and RLOC-probing procedures. 392 5.2. Map-Request Message Format 394 0 1 2 3 395 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 1 396 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 397 |Type=1 |A|M|P|S|p|s|m|I| Rsvd |L|D| IRC | Record Count | 398 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 399 | Nonce . . . | 400 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 401 | . . . Nonce | 402 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 403 | Source-EID-AFI | Source EID Address ... | 404 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 405 | ITR-RLOC-AFI 1 | ITR-RLOC Address 1 ... | 406 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 407 | ... | 408 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 409 | ITR-RLOC-AFI n | ITR-RLOC Address n ... | 410 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 411 / | Reserved | EID mask-len | EID-Prefix-AFI | 412 Rec +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 413 \ | EID-Prefix ... | 414 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 415 | Map-Reply Record ... | 416 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 418 Packet field descriptions: 420 Type: 1 (Map-Request) 422 A: This is an authoritative bit, which is set to 0 for UDP-based Map- 423 Requests sent by an ITR. It is set to 1 when an ITR wants the 424 destination site to return the Map-Reply rather than the mapping 425 database system. 427 M: This is the map-data-present bit. When set, it indicates that a 428 Map-Reply Record segment is included in the Map-Request. 430 P: This is the probe-bit, which indicates that a Map-Request SHOULD 431 be treated as a Locator reachability probe. The receiver SHOULD 432 respond with a Map-Reply with the probe-bit set, indicating that 433 the Map-Reply is a Locator reachability probe reply, with the 434 nonce copied from the Map-Request. See RLOC-Probing Section 7.1 435 for more details. 437 S: This is the Solicit-Map-Request (SMR) bit. See Solicit-Map- 438 Request (SMRs) Section 6.1 for details. 440 p: This is the PITR bit. This bit is set to 1 when a PITR sends a 441 Map-Request. 443 s: This is the SMR-invoked bit. This bit is set to 1 when an xTR is 444 sending a Map-Request in response to a received SMR-based Map- 445 Request. 447 m: This is the LISP mobile-node m-bit. This bit is set by xTRs that 448 operate as a mobile node as defined in [I-D.ietf-lisp-mn]. 450 I: This is the xTR-ID bit. When this bit is set, what is appended to 451 the Map-Request is a 128-bit xTR router-ID. See LISP PubSub usage 452 procedures in [I-D.rodrigueznatal-lisp-pubsub] for details. 454 Rsvd: This field MUST be set to 0 on transmit and MUST be ignored on 455 receipt. 457 L: This is the local-xtr bit. It is used by an xTR in a LISP site to 458 tell other xTRs in the same site that it is part of the RLOC-set 459 for the LISP site. The L-bit is set to 1 when the RLOC is the 460 sender's IP address. 462 D: This is the dont-map-reply bit. It is used in the SMR procedure 463 described in Section 6.1. When an xTR sends an SMR Map-Request 464 message, it doesn't need a Map-Reply returned. When this bit is 465 set, the receiver of the Map-Request does not return a Map-Reply. 467 IRC: This 5-bit field is the ITR-RLOC Count, which encodes the 468 additional number of ('ITR-RLOC-AFI', 'ITR-RLOC Address') fields 469 present in this message. At least one (ITR-RLOC-AFI, ITR-RLOC- 470 Address) pair MUST be encoded. Multiple 'ITR-RLOC Address' fields 471 are used, so a Map-Replier can select which destination address to 472 use for a Map-Reply. The IRC value ranges from 0 to 31. For a 473 value of 0, there is 1 ITR-RLOC address encoded; for a value of 1, 474 there are 2 ITR-RLOC addresses encoded, and so on up to 31, which 475 encodes a total of 32 ITR-RLOC addresses. 477 Record Count: This is the number of records in this Map-Request 478 message. A record is comprised of the portion of the packet that 479 is labeled 'Rec' above and occurs the number of times equal to 480 Record Count. For this version of the protocol, a receiver MUST 481 accept and process Map-Requests that contain one or more records, 482 but a sender MUST only send Map-Requests containing one record. 483 Support for requesting multiple EIDs in a single Map-Request 484 message will be specified in a future version of the protocol. 486 Nonce: This is an 8-octet random value created by the sender of the 487 Map-Request. This nonce will be returned in the Map-Reply. The 488 security of the LISP mapping protocol critically depends on the 489 strength of the nonce in the Map-Request message. The nonce 490 SHOULD be generated by a properly seeded pseudo-random (or strong 491 random) source. See [RFC4086] for advice on generating security- 492 sensitive random data. 494 Source-EID-AFI: This is the address family of the 'Source EID 495 Address' field. 497 Source EID Address: This is the EID of the source host that 498 originated the packet that caused the Map-Request. When Map- 499 Requests are used for refreshing a Map-Cache entry or for RLOC- 500 Probing, an AFI value 0 is used and this field is of zero length. 502 ITR-RLOC-AFI: This is the address family of the 'ITR-RLOC Address' 503 field that follows this field. 505 ITR-RLOC Address: This is used to give the ETR the option of 506 selecting the destination address from any address family for the 507 Map-Reply message. This address MUST be a routable RLOC address 508 of the sender of the Map-Request message. 510 EID mask-len: This is the mask length for the EID-Prefix. 512 EID-Prefix-AFI: This is the address family of the EID-Prefix 513 according to [AFI] and [RFC8060]. 515 EID-Prefix: This prefix is 4 octets for an IPv4 address family and 516 16 octets for an IPv6 address family when the EID-Prefix-AFI is 1 517 or 2, respectively. For other AFIs [AFI], the length varies and 518 for the LCAF AFI the format is defined in [RFC8060]. When a Map- 519 Request is sent by an ITR because a data packet is received for a 520 destination where there is no mapping entry, the EID-Prefix is set 521 to the destination IP address of the data packet, and the 'EID 522 mask-len' is set to 32 or 128 for IPv4 or IPv6, respectively. 523 When an xTR wants to query a site about the status of a mapping it 524 already has cached, the EID-Prefix used in the Map-Request has the 525 same mask length as the EID-Prefix returned from the site when it 526 sent a Map-Reply message. 528 Map-Reply Record: When the M-bit is set, this field is the size of a 529 single "Record" in the Map-Reply format. This Map-Reply record 530 contains the EID-to-RLOC mapping entry associated with the Source 531 EID. This allows the ETR that will receive this Map-Request to 532 cache the data if it chooses to do so. 534 5.3. EID-to-RLOC UDP Map-Request Message 536 A Map-Request is sent from an ITR when it needs a mapping for an EID, 537 wants to test an RLOC for reachability, or wants to refresh a mapping 538 before TTL expiration. For the initial case, the destination IP 539 address used for the Map-Request is the data packet's destination 540 address (i.e., the destination EID) that had a mapping cache lookup 541 failure. For the latter two cases, the destination IP address used 542 for the Map-Request is one of the RLOC addresses from the Locator-Set 543 of the Map-Cache entry. The source address is either an IPv4 or IPv6 544 RLOC address, depending on whether the Map-Request is using an IPv4 545 or IPv6 header, respectively. In all cases, the UDP source port 546 number for the Map-Request message is a 16-bit value selected by the 547 ITR/PITR, and the UDP destination port number is set to the well- 548 known destination port number 4342. A successful Map-Reply, which is 549 one that has a nonce that matches an outstanding Map-Request nonce, 550 will update the cached set of RLOCs associated with the EID-Prefix 551 range. 553 One or more Map-Request ('ITR-RLOC-AFI', 'ITR-RLOC-Address') fields 554 MUST be filled in by the ITR. The number of fields (minus 1) encoded 555 MUST be placed in the 'IRC' field. The ITR MAY include all locally 556 configured Locators in this list or just provide one locator address 557 from each address family it supports. If the ITR erroneously 558 provides no ITR-RLOC addresses, the Map-Replier MUST drop the Map- 559 Request. 561 Map-Requests can also be LISP encapsulated using UDP destination 562 port 4342 with a LISP Type value set to "Encapsulated Control 563 Message", when sent from an ITR to a Map-Resolver. Likewise, Map- 564 Requests are LISP encapsulated the same way from a Map-Server to an 565 ETR. Details on Encapsulated Map-Requests and Map-Resolvers can be 566 found in Section 5.8. 568 Map-Requests MUST be rate-limited. It is RECOMMENDED that a Map- 569 Request for the same EID-Prefix be sent no more than once per second. 571 An ITR that is configured with mapping database information (i.e., it 572 is also an ETR) MAY optionally include those mappings in a Map- 573 Request. When an ETR configured to accept and verify such 574 "piggybacked" mapping data receives such a Map-Request and it does 575 not have this mapping in the Map-Cache, it MAY originate a "verifying 576 Map-Request", addressed to the map-requesting ITR and the ETR MAY add 577 a Map-Cache entry. If the ETR has a Map-Cache entry that matches the 578 "piggybacked" EID and the RLOC is in the Locator-Set for the entry, 579 then it MAY send the "verifying Map-Request" directly to the 580 originating Map-Request source. If the RLOC is not in the Locator- 581 Set, then the ETR MUST send the "verifying Map-Request" to the 582 "piggybacked" EID. Doing this forces the "verifying Map-Request" to 583 go through the mapping database system to reach the authoritative 584 source of information about that EID, guarding against RLOC-spoofing 585 in the "piggybacked" mapping data. 587 5.4. Map-Reply Message Format 589 0 1 2 3 590 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 1 591 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 592 |Type=2 |P|E|S| Reserved | Record Count | 593 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 594 | Nonce . . . | 595 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 596 | . . . Nonce | 597 +-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 598 | | Record TTL | 599 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 600 R | Locator Count | EID mask-len | ACT |A| Reserved | 601 e +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 602 c | Rsvd | Map-Version Number | EID-Prefix-AFI | 603 o +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 604 r | EID-Prefix | 605 d +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 606 | /| Priority | Weight | M Priority | M Weight | 607 | L +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 608 | o | Unused Flags |L|p|R| Loc-AFI | 609 | c +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 610 | \| Locator | 611 +-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 613 Packet field descriptions: 615 Type: 2 (Map-Reply) 617 P: This is the probe-bit, which indicates that the Map-Reply is in 618 response to a Locator reachability probe Map-Request. The 'Nonce' 619 field MUST contain a copy of the nonce value from the original 620 Map-Request. See RLOC-probing Section 7.1 for more details. When 621 the probe-bit is set to 1 in a Map-Reply message, the A-bit in 622 each EID-record included in the message MUST be set to 1. 624 E: This bit indicates that the ETR that sends this Map-Reply message 625 is advertising that the site is enabled for the Echo-Nonce Locator 626 reachability algorithm. See Echo-Nonce [I-D.ietf-lisp-rfc6830bis] 627 for more details. 629 S: This is the Security bit. When set to 1, the following 630 authentication information will be appended to the end of the Map- 631 Reply. The details of signing a Map-Reply message can be found in 632 [I-D.ietf-lisp-sec]. 634 0 1 2 3 635 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 1 636 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 637 | AD Type | Authentication Data Content . . . | 638 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 640 Reserved: This field MUST be set to 0 on transmit and MUST be 641 ignored on receipt. 643 Record Count: This is the number of records in this reply message. 644 A record is comprised of that portion of the packet labeled 645 'Record' above and occurs the number of times equal to Record 646 Count. 648 Nonce: This is a 24-bit value set in a Data-Probe 649 [I-D.ietf-lisp-rfc6830bis] or a 64-bit value from the Map-Request 650 is echoed in this 'Nonce' field of the Map-Reply. When a 24-bit 651 value is supplied, it resides in the low-order 64 bits of the 652 'Nonce' field. 654 Record TTL: This is the time in minutes the recipient of the Map- 655 Reply will store the mapping. If the TTL is 0, the entry MUST be 656 removed from the cache immediately. If the value is 0xffffffff, 657 the recipient can decide locally how long to store the mapping. 659 Locator Count: This is the number of Locator entries. A Locator 660 entry comprises what is labeled above as 'Loc'. The Locator count 661 can be 0, indicating that there are no Locators for the EID- 662 Prefix. 664 EID mask-len: This is the mask length for the EID-Prefix. 666 ACT: This 3-bit field describes Negative Map-Reply actions. In any 667 other message type, these bits are set to 0 and ignored on 668 receipt. These bits are used only when the 'Locator Count' field 669 is set to 0. The action bits are encoded only in Map-Reply 670 messages. The actions defined are used by an ITR or PITR when a 671 destination EID matches a negative Map-Cache entry. Unassigned 672 values SHOULD cause a Map-Cache entry to be created, and when 673 packets match this negative cache entry, they will be dropped. 674 The current assigned values are: 676 (0) No-Action: The Map-Cache is kept alive, and no packet 677 encapsulation occurs. 679 (1) Natively-Forward: The packet is not encapsulated or dropped 680 but natively forwarded. 682 (2) Send-Map-Request: The packet invokes sending a Map-Request. 684 (3) Drop/No-Reason: A packet that matches this Map-Cache entry is 685 dropped. An ICMP Destination Unreachable message SHOULD be 686 sent. 688 (4) Drop/Policy-Denied: A packet that matches this Map-Cache 689 entry is dropped. The reason for the Drop action is that a 690 Map-Request for the target-EID is being policy denied by 691 either an xTR or the mapping system. 693 (5) Drop/Authentication-Failure: A packet that matches this Map- 694 Cache entry is dropped. The reason for the Drop action is 695 that a Map-Request for the target-EID fails an authentication 696 verification-check by either an xTR or the mapping system. 698 A: The Authoritative bit, when sent, is always set to 1 by an ETR. 699 When a Map-Server is proxy Map-Replying for a LISP site, the 700 Authoritative bit is set to 0. This indicates to requesting ITRs 701 that the Map-Reply was not originated by a LISP node managed at 702 the site that owns the EID-Prefix. 704 Map-Version Number: When this 12-bit value is non-zero, the Map- 705 Reply sender is informing the ITR what the version number is for 706 the EID record contained in the Map-Reply. The ETR can allocate 707 this number internally but MUST coordinate this value with other 708 ETRs for the site. When this value is 0, there is no versioning 709 information conveyed. The Map-Version Number can be included in 710 Map-Request and Map-Register messages. See Map-Versioning 711 [RFC6834] for more details. 713 EID-Prefix-AFI: Address family of the EID-Prefix according to [AFI] 714 and [RFC8060]. 716 EID-Prefix: This prefix is 4 octets for an IPv4 address family and 717 16 octets for an IPv6 address family. 719 Priority: Each RLOC is assigned a unicast Priority. Lower values 720 are more preferable. When multiple RLOCs have the same Priority, 721 they MAY be used in a load-split fashion. A value of 255 means 722 the RLOC MUST NOT be used for unicast forwarding. 724 Weight: When priorities are the same for multiple RLOCs, the Weight 725 indicates how to balance unicast traffic between them. Weight is 726 encoded as a relative weight of total unicast packets that match 727 the mapping entry. For example, if there are 4 Locators in a 728 Locator-Set, where the Weights assigned are 30, 20, 20, and 10, 729 the first Locator will get 37.5% of the traffic, the 2nd and 3rd 730 Locators will get 25% of the traffic, and the 4th Locator will get 731 12.5% of the traffic. If all Weights for a Locator-Set are equal, 732 the receiver of the Map-Reply will decide how to load-split the 733 traffic. See RLOC-hashing [I-D.ietf-lisp-rfc6830bis] for a 734 suggested hash algorithm to distribute the load across Locators 735 with the same Priority and equal Weight values. 737 M Priority: Each RLOC is assigned a multicast Priority used by an 738 ETR in a receiver multicast site to select an ITR in a source 739 multicast site for building multicast distribution trees. A value 740 of 255 means the RLOC MUST NOT be used for joining a multicast 741 distribution tree. For more details, see [RFC6831]. 743 M Weight: When priorities are the same for multiple RLOCs, the 744 Weight indicates how to balance building multicast distribution 745 trees across multiple ITRs. The Weight is encoded as a relative 746 weight (similar to the unicast Weights) of the total number of 747 trees built to the source site identified by the EID-Prefix. If 748 all Weights for a Locator-Set are equal, the receiver of the Map- 749 Reply will decide how to distribute multicast state across ITRs. 750 For more details, see [RFC6831]. 752 Unused Flags: These are set to 0 when sending and ignored on 753 receipt. 755 L: When this bit is set, the Locator is flagged as a local Locator to 756 the ETR that is sending the Map-Reply. When a Map-Server is doing 757 proxy Map-Replying for a LISP site, the L-bit is set to 0 for all 758 Locators in this Locator-Set. 760 p: When this bit is set, an ETR informs the RLOC-Probing ITR that the 761 locator address for which this bit is set is the one being RLOC- 762 probed and MAY be different from the source address of the Map- 763 Reply. An ITR that RLOC-probes a particular Locator MUST use this 764 Locator for retrieving the data structure used to store the fact 765 that the Locator is reachable. The p-bit is set for a single 766 Locator in the same Locator-Set. If an implementation sets more 767 than one p-bit erroneously, the receiver of the Map-Reply MUST 768 select the first Locator. The p-bit MUST NOT be set for Locator- 769 Set records sent in Map-Request and Map-Register messages. 771 R: This is set when the sender of a Map-Reply has a route to the 772 Locator in the Locator data record. This receiver MAY find this 773 useful to know if the Locator is up but not necessarily reachable 774 from the receiver's point of view. See also EID-Reachability 775 Section 7.1 for another way the R-bit MAY be used. 777 Locator: This is an IPv4 or IPv6 address (as encoded by the 'Loc- 778 AFI' field) assigned to an ETR. Note that the destination RLOC 779 address MAY be an anycast address. A source RLOC can be an 780 anycast address as well. The source or destination RLOC MUST NOT 781 be the broadcast address (255.255.255.255 or any subnet broadcast 782 address known to the router) and MUST NOT be a link-local 783 multicast address. The source RLOC MUST NOT be a multicast 784 address. The destination RLOC SHOULD be a multicast address if it 785 is being mapped from a multicast destination EID. 787 5.5. EID-to-RLOC UDP Map-Reply Message 789 A Map-Reply returns an EID-Prefix with a prefix length that is less 790 than or equal to the EID being requested. The EID being requested is 791 either from the destination field of an IP header of a Data-Probe or 792 the EID record of a Map-Request. The RLOCs in the Map-Reply are 793 routable IP addresses of all ETRs for the LISP site. Each RLOC 794 conveys status reachability but does not convey path reachability 795 from a requester's perspective. Separate testing of path 796 reachability is required. See RLOC-reachability Section 7.1 for 797 details. 799 Note that a Map-Reply MAY contain different EID-Prefix granularity 800 (prefix + length) than the Map-Request that triggers it. This might 801 occur if a Map-Request were for a prefix that had been returned by an 802 earlier Map-Reply. In such a case, the requester updates its cache 803 with the new prefix information and granularity. For example, a 804 requester with two cached EID-Prefixes that are covered by a Map- 805 Reply containing one less-specific prefix replaces the entry with the 806 less-specific EID-Prefix. Note that the reverse, replacement of one 807 less-specific prefix with multiple more-specific prefixes, can also 808 occur, not by removing the less-specific prefix but rather by adding 809 the more-specific prefixes that, during a lookup, will override the 810 less-specific prefix. 812 When an EID moves out of a LISP site [I-D.ietf-lisp-eid-mobility], 813 the database mapping system may have overlapping EID-prefixes. Or 814 when a LISP site is configured with multiple sets of ETRs that 815 support different EID-prefix lengths, the database mapping system may 816 have overlapping EID-prefixes. When overlapping EID-prefixes exist, 817 a Map-Request with an EID that best matches any EID-Prefix MUST be 818 returned in a single Map-Reply message. For instance, if an ETR had 819 database mapping entries for EID-Prefixes: 821 10.0.0.0/8 822 10.1.0.0/16 823 10.1.1.0/24 824 10.1.2.0/24 826 A Map-Request for EID 10.1.1.1 would cause a Map-Reply with a record 827 count of 1 to be returned with a mapping record EID-Prefix of 828 10.1.1.0/24. 830 A Map-Request for EID 10.1.5.5 would cause a Map-Reply with a record 831 count of 3 to be returned with mapping records for EID-Prefixes 832 10.1.0.0/16, 10.1.1.0/24, and 10.1.2.0/24. 834 Note that not all overlapping EID-Prefixes need to be returned but 835 only the more-specific entries (note that in the second example above 836 10.0.0.0/8 was not returned for requesting EID 10.1.5.5) for the 837 matching EID-Prefix of the requesting EID. When more than one EID- 838 Prefix is returned, all SHOULD use the same Time to Live value so 839 they can all time out at the same time. When a more-specific EID- 840 Prefix is received later, its Time to Live value in the Map-Reply 841 record can be stored even when other less-specific entries exist. 842 When a less-specific EID-Prefix is received later, its Map-Cache 843 expiration time SHOULD be set to the minimum expiration time of any 844 more-specific EID-Prefix in the Map-Cache. This is done so the 845 integrity of the EID-Prefix set is wholly maintained and so no more- 846 specific entries are removed from the Map-Cache while keeping less- 847 specific entries. 849 Map-Replies SHOULD be sent for an EID-Prefix no more often than once 850 per second to the same requesting router. For scalability, it is 851 expected that aggregation of EID addresses into EID-Prefixes will 852 allow one Map-Reply to satisfy a mapping for the EID addresses in the 853 prefix range, thereby reducing the number of Map-Request messages. 855 Map-Reply records can have an empty Locator-Set. A Negative Map- 856 Reply is a Map-Reply with an empty Locator-Set. Negative Map-Replies 857 convey special actions by the sender to the ITR or PITR that have 858 solicited the Map-Reply. There are two primary applications for 859 Negative Map-Replies. The first is for a Map-Resolver to instruct an 860 ITR or PITR when a destination is for a LISP site versus a non-LISP 861 site, and the other is to source quench Map-Requests that are sent 862 for non-allocated EIDs. 864 For each Map-Reply record, the list of Locators in a Locator-Set MUST 865 appear in the same order for each ETR that originates a Map-Reply 866 message. The Locator-Set MUST be sorted in order of ascending IP 867 address where an IPv4 locator address is considered numerically 'less 868 than' an IPv6 locator address. 870 When sending a Map-Reply message, the destination address is copied 871 from one of the 'ITR-RLOC' fields from the Map-Request. The ETR can 872 choose a locator address from one of the address families it 873 supports. For Data-Probes, the destination address of the Map-Reply 874 is copied from the source address of the Data-Probe message that is 875 invoking the reply. The source address of the Map-Reply is one of 876 the local IP addresses chosen to allow Unicast Reverse Path 877 Forwarding (uRPF) checks to succeed in the upstream service provider. 878 The destination port of a Map-Reply message is copied from the source 879 port of the Map-Request or Data-Probe, and the source port of the 880 Map-Reply message is set to the well-known UDP port 4342. 882 5.6. Map-Register Message Format 884 This section specifies the encoding format for the Map-Register 885 message. The message is sent in UDP with a destination UDP port of 886 4342 and a randomly selected UDP source port number. 888 The Map-Register message format is: 890 0 1 2 3 891 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 1 892 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 893 |Type=3 |P|S|I| Reserved |E|T|a|m|M| Record Count | 894 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 895 | Nonce . . . | 896 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 897 | . . . Nonce | 898 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 899 | Key ID | Algorithm ID | Authentication Data Length | 900 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 901 ~ Authentication Data ~ 902 +-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 903 | | Record TTL | 904 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 905 R | Locator Count | EID mask-len | ACT |A| Reserved | 906 e +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 907 c | Rsvd | Map-Version Number | EID-Prefix-AFI | 908 o +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 909 r | EID-Prefix | 910 d +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 911 | /| Priority | Weight | M Priority | M Weight | 912 | L +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 913 | o | Unused Flags |L|p|R| Loc-AFI | 914 | c +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 915 | \| Locator | 916 +-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 918 Packet field descriptions: 920 Type: 3 (Map-Register) 922 P: This is the proxy Map-Reply bit. When set to 1, an ETR sends a 923 Map-Register message requesting the Map-Server to proxy a Map- 924 Reply. The Map-Server will send non-authoritative Map-Replies on 925 behalf of the ETR. 927 S: This is the security-capable bit. When set, the procedures from 928 [I-D.ietf-lisp-sec] are supported. 930 I: This is the xTR-ID bit. When this bit is set, what is appended to 931 the Map-Register is a 128-bit xTR router-ID and then a 64-bit 932 site-ID. See LISP NAT-Traversal procedures in 933 [I-D.ermagan-lisp-nat-traversal] for details. 935 Reserved: This field MUST be set to 0 on transmit and MUST be 936 ignored on receipt. 938 E: This is the Map-Register EID-notify bit. This is used by a First- 939 Hop-Router (FHR) which discovers a dynamic-EID. This EID-notify 940 based Map-Register is sent by the FHR to the same site xTR that 941 propogates the Map-Register to the mapping system. The site xTR 942 keeps state to later Map-Notify the FHR after the EID has moves 943 away. See [I-D.ietf-lisp-eid-mobility] for a detailed use-case. 945 T: This is the use-TTL for timeout bit. When set to 1, the xTR wants 946 the Map-Server to time out registrations based on the value in the 947 "Record TTL" field of this message. 949 a: This is the merge-request bit. When set to 1, the xTR requests to 950 merge RLOC-records from different xTRs registering the same EID- 951 record. See signal-free multicast 952 [I-D.ietf-lisp-signal-free-multicast] for one use case example. 954 m: This is the mobile-node bit. When set to 1, the registering xTR 955 supports the procedures in [I-D.ietf-lisp-mn]. 957 M: This is the want-map-notify bit. When set to 1, an ETR is 958 requesting a Map-Notify message to be returned in response to 959 sending a Map-Register message. The Map-Notify message sent by a 960 Map-Server is used to acknowledge receipt of a Map-Register 961 message. 963 Record Count: This is the number of records in this Map-Register 964 message. A record is comprised of that portion of the packet 965 labeled 'Record' above and occurs the number of times equal to 966 Record Count. 968 Nonce: This 8-octet 'Nonce' field is set to 0 in Map-Register 969 messages if no Map-Notify message is expected to acknowledge it. 970 Since the Map-Register message is authenticated, the 'Nonce' field 971 is not currently used for any security function but MAY be in the 972 future as part of an anti-replay solution. 974 Key ID: This is a configured key-id value that corresponds to a 975 shared-secret password that is used to authenticate the sender. 976 Multiple shared-secrets can be used to roll over keys in a non- 977 disruptive way. 979 Algorithm ID: This is the configured Message Authentication Code 980 (MAC) algorithm value used for the authentication function. See 981 Algorithm ID Numbers in the Section 10.5 for codepoint 982 assignments. 984 Authentication Data Length: This is the length in octets of the 985 'Authentication Data' field that follows this field. The length 986 of the 'Authentication Data' field is dependent on the MAC 987 algorithm used. The length field allows a device that doesn't 988 know the MAC algorithm to correctly parse the packet. 990 Authentication Data: This is the message digest used from the output 991 of the MAC algorithm. The entire Map-Register payload is 992 authenticated with this field preset to 0. After the MAC is 993 computed, it is placed in this field. Implementations of this 994 specification MUST include support for HMAC-SHA-1-96 [RFC2404], 995 and support for HMAC-SHA-256-128 [RFC4868] is RECOMMENDED. 997 The definition of the rest of the Map-Register can be found in EID- 998 record description in Section 5.4. 1000 5.7. Map-Notify/Map-Notify-Ack Message Format 1002 This section specifies the encoding format for the Map-Notify and 1003 Map-Notify-Ack messages. The messages are sent inside a UDP packet 1004 with source and destination UDP ports equal to 4342. 1006 The Map-Notify and Map-Notify-Ack message formats are: 1008 0 1 2 3 1009 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 1010 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1011 |Type=4/5| Reserved | Record Count | 1012 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1013 | Nonce . . . | 1014 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1015 | . . . Nonce | 1016 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1017 | Key ID | Algorithm ID | Authentication Data Length | 1018 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1019 ~ Authentication Data ~ 1020 +-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1021 | | Record TTL | 1022 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1023 R | Locator Count | EID mask-len | ACT |A| Reserved | 1024 e +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1025 c | Rsvd | Map-Version Number | EID-Prefix-AFI | 1026 o +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1027 r | EID-Prefix | 1028 d +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1029 | /| Priority | Weight | M Priority | M Weight | 1030 | L +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1031 | o | Unused Flags |L|p|R| Loc-AFI | 1032 | c +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1033 | \| Locator | 1034 +-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1036 Packet field descriptions: 1038 Type: 4/5 (Map-Notify/Map-Notify-Ack) 1040 The Map-Notify message has the same contents as a Map-Register 1041 message. See the Map-Register section for field descriptions. 1043 The Map-Notify-Ack message has the same contents as a Map-Notify 1044 message. It is used to acknowledge the receipt of a Map-Notify and 1045 for the sender to stop retransmitting a Map-Notify with the same 1046 nonce. 1048 5.8. Encapsulated Control Message Format 1050 An Encapsulated Control Message (ECM) is used to encapsulate control 1051 packets sent between xTRs and the mapping database system. 1053 0 1 2 3 1054 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 1055 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1056 / | IPv4 or IPv6 Header | 1057 OH | (uses RLOC addresses) | 1058 \ | | 1059 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1060 / | Source Port = xxxx | Dest Port = 4342 | 1061 UDP +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1062 \ | UDP Length | UDP Checksum | 1063 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1064 LH |Type=8 |S|D|E|M| Reserved | 1065 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1066 / | IPv4 or IPv6 Header | 1067 IH | (uses RLOC or EID addresses) | 1068 \ | | 1069 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1070 / | Source Port = xxxx | Dest Port = yyyy | 1071 UDP +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1072 \ | UDP Length | UDP Checksum | 1073 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1074 LCM | LISP Control Message | 1075 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1077 Packet header descriptions: 1079 OH: The outer IPv4 or IPv6 header, which uses RLOC addresses in the 1080 source and destination header address fields. 1082 UDP: The outer UDP header with destination port 4342. The source 1083 port is randomly allocated. The checksum field MUST be non- 1084 zero. 1086 LH: Type 8 is defined to be a "LISP Encapsulated Control Message", 1087 and what follows is either an IPv4 or IPv6 header as encoded by 1088 the first 4 bits after the 'Reserved' field. 1090 Type: 8 (Encapsulated Control Message (ECM)) 1092 S: This is the Security bit. When set to 1, the procedures from 1093 [I-D.ietf-lisp-sec] are followed. 1095 D: This is the DDT-bit. When set to 1, the sender is requesting a 1096 Map-Referral message to be returned. The details of this 1097 procedure are described in [RFC8111]. 1099 E: This is the to-ETR bit. When set to 1, the Map-Server's 1100 intention is to forward the ECM to an authoritative ETR. 1102 M: This is the to-MS bit. When set to 1, a Map-Request is being 1103 sent to a co-located Map-Resolver and Map-Server where the 1104 message can be processed directly by the Map-Server versus the 1105 Map-Resolver using the LISP-DDT procedures in [RFC8111]. 1107 0 1 2 3 1108 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 1109 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1110 | AD Type | Authentication Data Content . . . | 1111 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1113 IH: The inner IPv4 or IPv6 header, which can use either RLOC or EID 1114 addresses in the header address fields. When a Map-Request is 1115 encapsulated in this packet format, the destination address in 1116 this header is an EID. 1118 UDP: The inner UDP header, where the port assignments depend on the 1119 control packet being encapsulated. When the control packet is 1120 a Map-Request or Map-Register, the source port is selected by 1121 the ITR/PITR and the destination port is 4342. When the 1122 control packet is a Map-Reply, the source port is 4342 and the 1123 destination port is assigned from the source port of the 1124 invoking Map-Request. Port number 4341 MUST NOT be assigned to 1125 either port. The checksum field MUST be non-zero. 1127 LCM: The format is one of the control message formats described in 1128 this section. At this time, only Map-Request messages are 1129 allowed to be Control-Plane (ECM) encapsulated. In the future, 1130 PIM Join/Prune messages [RFC6831] might be allowed. 1131 Encapsulating other types of LISP control messages is for 1132 further study. When Map-Requests are sent for RLOC-Probing 1133 purposes (i.e., the probe-bit is set), they MUST NOT be sent 1134 inside Encapsulated Control Messages. 1136 6. Changing the Contents of EID-to-RLOC Mappings 1138 In the LISP architecture ITRs/PITRs use a local Map-Cache to store 1139 EID-to-RLOC mappings for forwarding. When an ETR updates a mapping a 1140 mechanism is required to inform ITRs/PITRs that are using such 1141 mappings. 1143 The LISP Data-Plane defines several mechanism to update mappings 1144 [I-D.ietf-lisp-rfc6830bis]. This document specifies the Solicit-Map 1145 Request (SMR), a Control-Plane push-based mechanism. An additional 1146 Control-Plane mechanism based on the Publish/subscribe paradigm is 1147 specified in [I-D.rodrigueznatal-lisp-pubsub]. 1149 6.1. Solicit-Map-Request (SMR) 1151 Soliciting a Map-Request is a selective way for ETRs, at the site 1152 where mappings change, to control the rate they receive requests for 1153 Map-Reply messages. SMRs are also used to tell remote ITRs to update 1154 the mappings they have cached. 1156 Since the ETRs don't keep track of remote ITRs that have cached their 1157 mappings, they do not know which ITRs need to have their mappings 1158 updated. As a result, an ETR will solicit Map-Requests (called an 1159 SMR message) from those sites to which it has been sending 1160 encapsulated data for the last minute. In particular, an ETR will 1161 send an SMR to an ITR to which it has recently sent encapsulated 1162 data. This can only occur when both ITR and ETR functionality reside 1163 in the same router. 1165 An SMR message is simply a bit set in a Map-Request message. An ITR 1166 or PITR will send a Map-Request when they receive an SMR message. 1167 Both the SMR sender and the Map-Request responder MUST rate-limit 1168 these messages. Rate-limiting can be implemented as a global rate- 1169 limiter or one rate-limiter per SMR destination. 1171 The following procedure shows how an SMR exchange occurs when a site 1172 is doing Locator-Set compaction for an EID-to-RLOC mapping: 1174 1. When the database mappings in an ETR change, the ETRs at the site 1175 begin to send Map-Requests with the SMR bit set for each Locator 1176 in each Map-Cache entry the ETR caches. 1178 2. A remote ITR that receives the SMR message will schedule sending 1179 a Map-Request message to the source locator address of the SMR 1180 message or to the mapping database system. A newly allocated 1181 random nonce is selected, and the EID-Prefix used is the one 1182 copied from the SMR message. If the source Locator is the only 1183 Locator in the cached Locator-Set, the remote ITR SHOULD send a 1184 Map-Request to the database mapping system just in case the 1185 single Locator has changed and may no longer be reachable to 1186 accept the Map-Request. 1188 3. The remote ITR MUST rate-limit the Map-Request until it gets a 1189 Map-Reply while continuing to use the cached mapping. When 1190 Map-Versioning as described in [RFC6834] is used, an SMR sender 1191 can detect if an ITR is using the most up-to-date database 1192 mapping. 1194 4. The ETRs at the site with the changed mapping will reply to the 1195 Map-Request with a Map-Reply message that has a nonce from the 1196 SMR-invoked Map-Request. The Map-Reply messages SHOULD be rate- 1197 limited. This is important to avoid Map-Reply implosion. 1199 5. The ETRs at the site with the changed mapping record the fact 1200 that the site that sent the Map-Request has received the new 1201 mapping data in the Map-Cache entry for the remote site so the 1202 Locator-Status-Bits are reflective of the new mapping for packets 1203 going to the remote site. The ETR then stops sending SMR 1204 messages. 1206 For security reasons, an ITR MUST NOT process unsolicited Map- 1207 Replies. To avoid Map-Cache entry corruption by a third party, a 1208 sender of an SMR-based Map-Request MUST be verified. If an ITR 1209 receives an SMR-based Map-Request and the source is not in the 1210 Locator-Set for the stored Map-Cache entry, then the responding Map- 1211 Request MUST be sent with an EID destination to the mapping database 1212 system. Since the mapping database system is a more secure way to 1213 reach an authoritative ETR, it will deliver the Map-Request to the 1214 authoritative source of the mapping data. 1216 When an ITR receives an SMR-based Map-Request for which it does not 1217 have a cached mapping for the EID in the SMR message, it may not send 1218 an SMR-invoked Map-Request. This scenario can occur when an ETR 1219 sends SMR messages to all Locators in the Locator-Set it has stored 1220 in its Map-Cache but the remote ITRs that receive the SMR may not be 1221 sending packets to the site. There is no point in updating the ITRs 1222 until they need to send, in which case they will send Map-Requests to 1223 obtain a Map-Cache entry. 1225 7. Routing Locator Reachability 1227 This document defines several Control-Plane mechanisms for 1228 determining RLOC reachability. Please note that additional Data- 1229 Plane reachability mechanisms are defined in 1230 [I-D.ietf-lisp-rfc6830bis]. 1232 1. An ITR MAY receive an ICMP Network Unreachable or Host 1233 Unreachable message for an RLOC it is using. This indicates that 1234 the RLOC is likely down. Note that trusting ICMP messages may 1235 not be desirable, but neither is ignoring them completely. 1236 Implementations are encouraged to follow current best practices 1237 in treating these conditions [I-D.ietf-opsec-icmp-filtering]. 1239 2. When an ITR participates in the routing protocol that operates in 1240 the underlay routing system, it can determine that an RLOC is 1241 down when no Routing Information Base (RIB) entry exists that 1242 matches the RLOC IP address. 1244 3. An ITR MAY receive an ICMP Port Unreachable message from a 1245 destination host. This occurs if an ITR attempts to use 1246 interworking [RFC6832] and LISP-encapsulated data is sent to a 1247 non-LISP-capable site. 1249 4. An ITR MAY receive a Map-Reply from an ETR in response to a 1250 previously sent Map-Request. The RLOC source of the Map-Reply is 1251 likely up, since the ETR was able to send the Map-Reply to the 1252 ITR. 1254 5. An ITR/ETR pair can use the 'RLOC-Probing' mechanism described 1255 below. 1257 When ITRs receive ICMP Network Unreachable or Host Unreachable 1258 messages as a method to determine unreachability, they will refrain 1259 from using Locators that are described in Locator lists of Map- 1260 Replies. However, using this approach is unreliable because many 1261 network operators turn off generation of ICMP Destination Unreachable 1262 messages. 1264 If an ITR does receive an ICMP Network Unreachable or Host 1265 Unreachable message, it MAY originate its own ICMP Destination 1266 Unreachable message destined for the host that originated the data 1267 packet the ITR encapsulated. 1269 Also, BGP-enabled ITRs can unilaterally examine the RIB to see if a 1270 locator address from a Locator-Set in a mapping entry matches a 1271 prefix. If it does not find one and BGP is running in the Default- 1272 Free Zone (DFZ), it can decide to not use the Locator even though the 1273 Locator-Status-Bits indicate that the Locator is up. In this case, 1274 the path from the ITR to the ETR that is assigned the Locator is not 1275 available. More details are in [I-D.meyer-loc-id-implications]. 1277 Optionally, an ITR can send a Map-Request to a Locator, and if a Map- 1278 Reply is returned, reachability of the Locator has been determined. 1279 Obviously, sending such probes increases the number of control 1280 messages originated by Tunnel Routers for active flows, so Locators 1281 are assumed to be reachable when they are advertised. 1283 This assumption does create a dependency: Locator unreachability is 1284 detected by the receipt of ICMP Host Unreachable messages. When a 1285 Locator has been determined to be unreachable, it is not used for 1286 active traffic; this is the same as if it were listed in a Map-Reply 1287 with Priority 255. 1289 The ITR can test the reachability of the unreachable Locator by 1290 sending periodic Requests. Both Requests and Replies MUST be rate- 1291 limited. Locator reachability testing is never done with data 1292 packets, since that increases the risk of packet loss for end-to-end 1293 sessions. 1295 7.1. RLOC-Probing Algorithm 1297 RLOC-Probing is a method that an ITR or PITR can use to determine the 1298 reachability status of one or more Locators that it has cached in a 1299 Map-Cache entry. The probe-bit of the Map-Request and Map-Reply 1300 messages is used for RLOC-Probing. 1302 RLOC-Probing is done in the control plane on a timer basis, where an 1303 ITR or PITR will originate a Map-Request destined to a locator 1304 address from one of its own locator addresses. A Map-Request used as 1305 an RLOC-probe is NOT encapsulated and NOT sent to a Map-Server or to 1306 the mapping database system as one would when soliciting mapping 1307 data. The EID record encoded in the Map-Request is the EID-Prefix of 1308 the Map-Cache entry cached by the ITR or PITR. The ITR MAY include a 1309 mapping data record for its own database mapping information that 1310 contains the local EID-Prefixes and RLOCs for its site. RLOC-probes 1311 are sent periodically using a jittered timer interval. 1313 When an ETR receives a Map-Request message with the probe-bit set, it 1314 returns a Map-Reply with the probe-bit set. The source address of 1315 the Map-Reply is set according to the procedure described in 1316 [I-D.ietf-lisp-rfc6830bis]. The Map-Reply SHOULD contain mapping 1317 data for the EID-Prefix contained in the Map-Request. This provides 1318 the opportunity for the ITR or PITR that sent the RLOC-probe to get 1319 mapping updates if there were changes to the ETR's database mapping 1320 entries. 1322 There are advantages and disadvantages of RLOC-Probing. The greatest 1323 benefit of RLOC-Probing is that it can handle many failure scenarios 1324 allowing the ITR to determine when the path to a specific Locator is 1325 reachable or has become unreachable, thus providing a robust 1326 mechanism for switching to using another Locator from the cached 1327 Locator. RLOC-Probing can also provide rough Round-Trip Time (RTT) 1328 estimates between a pair of Locators, which can be useful for network 1329 management purposes as well as for selecting low delay paths. The 1330 major disadvantage of RLOC-Probing is in the number of control 1331 messages required and the amount of bandwidth used to obtain those 1332 benefits, especially if the requirement for failure detection times 1333 is very small. 1335 8. Interactions with Other LISP Components 1337 8.1. ITR EID-to-RLOC Mapping Resolution 1339 An ITR is configured with one or more Map-Resolver addresses. These 1340 addresses are "Locators" (or RLOCs) and MUST be routable on the 1341 underlying core network; they MUST NOT need to be resolved through 1342 LISP EID-to-RLOC mapping, as that would introduce a circular 1343 dependency. When using a Map-Resolver, an ITR does not need to 1344 connect to any other database mapping system. In particular, the ITR 1345 need not connect to the LISP-ALT infrastructure or implement the BGP 1346 and GRE protocols that it uses. 1348 An ITR sends an Encapsulated Map-Request to a configured Map-Resolver 1349 when it needs an EID-to-RLOC mapping that is not found in its local 1350 Map-Cache. Using the Map-Resolver greatly reduces both the 1351 complexity of the ITR implementation and the costs associated with 1352 its operation. 1354 In response to an Encapsulated Map-Request, the ITR can expect one of 1355 the following: 1357 o An immediate Negative Map-Reply (with action code of "Natively- 1358 Forward", 15-minute Time to Live (TTL)) from the Map-Resolver if 1359 the Map-Resolver can determine that the requested EID does not 1360 exist. The ITR saves the EID-Prefix returned in the Map-Reply in 1361 its cache, marks it as non-LISP-capable, and knows not to attempt 1362 LISP encapsulation for destinations matching it. 1364 o A Negative Map-Reply, with action code of "Natively-Forward", from 1365 a Map-Server that is authoritative for an EID-Prefix that matches 1366 the requested EID but that does not have an actively registered, 1367 more-specific ID-prefix. In this case, the requested EID is said 1368 to match a "hole" in the authoritative EID-Prefix. If the 1369 requested EID matches a more-specific EID-Prefix that has been 1370 delegated by the Map-Server but for which no ETRs are currently 1371 registered, a 1-minute TTL is returned. If the requested EID 1372 matches a non-delegated part of the authoritative EID-Prefix, then 1373 it is not a LISP EID and a 15-minute TTL is returned. See 1374 Section 8.2 for discussion of aggregate EID-Prefixes and details 1375 of Map-Server EID-Prefix matching. 1377 o A LISP Map-Reply from the ETR that owns the EID-to-RLOC mapping or 1378 possibly from a Map-Server answering on behalf of the ETR. See 1379 Section 8.4 for more details on Map-Resolver message processing. 1381 Note that an ITR MAY be configured to both use a Map-Resolver and to 1382 participate in a LISP-ALT logical network. In such a situation, the 1383 ITR SHOULD send Map-Requests through the ALT network for any EID- 1384 Prefix learned via ALT BGP. Such a configuration is expected to be 1385 very rare, since there is little benefit to using a Map-Resolver if 1386 an ITR is already using LISP-ALT. There would be, for example, no 1387 need for such an ITR to send a Map-Request to a possibly non-existent 1388 EID (and rely on Negative Map-Replies) if it can consult the ALT 1389 database to verify that an EID-Prefix is present before sending that 1390 Map-Request. 1392 8.2. EID-Prefix Configuration and ETR Registration 1394 An ETR publishes its EID-Prefixes on a Map-Server by sending LISP 1395 Map-Register messages. A Map-Register message includes 1396 authentication data, so prior to sending a Map-Register message, the 1397 ETR and Map-Server SHOULD be configured with a shared secret or other 1398 relevant authentication information. A Map-Server's configuration 1399 SHOULD also include a list of the EID-Prefixes for which each ETR is 1400 authoritative. Upon receipt of a Map-Register from an ETR, a Map- 1401 Server accepts only EID-Prefixes that are configured for that ETR. 1402 Failure to implement such a check would leave the mapping system 1403 vulnerable to trivial EID-Prefix hijacking attacks. As developers 1404 and operators gain experience with the mapping system, additional, 1405 stronger security measures MAY be added to the registration process. 1407 In addition to the set of EID-Prefixes defined for each ETR that MAY 1408 register, a Map-Server is typically also configured with one or more 1409 aggregate prefixes that define the part of the EID numbering space 1410 assigned to it. When LISP-ALT is the database in use, aggregate EID- 1411 Prefixes are implemented as discard routes and advertised into ALT 1412 BGP. The existence of aggregate EID-Prefixes in a Map-Server's 1413 database means that it MAY receive Map Requests for EID-Prefixes that 1414 match an aggregate but do not match a registered prefix; Section 8.3 1415 describes how this is handled. 1417 Map-Register messages are sent periodically from an ETR to a Map- 1418 Server with a suggested interval between messages of one minute. A 1419 Map-Server SHOULD time out and remove an ETR's registration if it has 1420 not received a valid Map-Register message within the past 1421 three minutes. When first contacting a Map-Server after restart or 1422 changes to its EID-to-RLOC database mappings, an ETR MAY initially 1423 send Map-Register messages at an increased frequency, up to one every 1424 20 seconds. This "quick registration" period is limited to 1425 five minutes in duration. 1427 An ETR MAY request that a Map-Server explicitly acknowledge receipt 1428 and processing of a Map-Register message by setting the "want-map- 1429 notify" (M-bit) flag. A Map-Server that receives a Map-Register with 1430 this flag set will respond with a Map-Notify message. Typical use of 1431 this flag by an ETR would be to set it for Map-Register messages sent 1432 during the initial "quick registration" with a Map-Server but then 1433 set it only occasionally during steady-state maintenance of its 1434 association with that Map-Server. Note that the Map-Notify message 1435 is sent to UDP destination port 4342, not to the source port 1436 specified in the original Map-Register message. 1438 Note that a one-minute minimum registration interval during 1439 maintenance of an ETR-Map-Server association places a lower bound on 1440 how quickly and how frequently a mapping database entry can be 1441 updated. This MAY have implications for what sorts of mobility can 1442 be supported directly by the mapping system; shorter registration 1443 intervals or other mechanisms might be needed to support faster 1444 mobility in some cases. For a discussion on one way that faster 1445 mobility MAY be implemented for individual devices, please see 1446 [I-D.ietf-lisp-mn]. 1448 An ETR MAY also request, by setting the "proxy Map-Reply" flag 1449 (P-bit) in the Map-Register message, that a Map-Server answer Map- 1450 Requests instead of forwarding them to the ETR. See Section 7.1 for 1451 details on how the Map-Server sets certain flags (such as those 1452 indicating whether the message is authoritative and how returned 1453 Locators SHOULD be treated) when sending a Map-Reply on behalf of an 1454 ETR. When an ETR requests proxy reply service, it SHOULD include all 1455 RLOCs for all ETRs for the EID-Prefix being registered, along with 1456 the routable flag ("R-bit") setting for each RLOC. The Map-Server 1457 includes all of this information in Map-Reply messages that it sends 1458 on behalf of the ETR. This differs from a non-proxy registration, 1459 since the latter need only provide one or more RLOCs for a Map-Server 1460 to use for forwarding Map-Requests; the registration information is 1461 not used in Map-Replies, so it being incomplete is not incorrect. 1463 An ETR that uses a Map-Server to publish its EID-to-RLOC mappings 1464 does not need to participate further in the mapping database 1465 protocol(s). When using a LISP-ALT mapping database, for example, 1466 this means that the ETR does not need to implement GRE or BGP, which 1467 greatly simplifies its configuration and reduces its cost of 1468 operation. 1470 Note that use of a Map-Server does not preclude an ETR from also 1471 connecting to the mapping database (i.e., it could also connect to 1472 the LISP-ALT network), but doing so doesn't seem particularly useful, 1473 as the whole purpose of using a Map-Server is to avoid the complexity 1474 of the mapping database protocols. 1476 8.3. Map-Server Processing 1478 Once a Map-Server has EID-Prefixes registered by its client ETRs, it 1479 can accept and process Map-Requests for them. 1481 In response to a Map-Request (received over the ALT if LISP-ALT is in 1482 use), the Map-Server first checks to see if the destination EID 1483 matches a configured EID-Prefix. If there is no match, the Map- 1484 Server returns a Negative Map-Reply with action code "Natively- 1485 Forward" and a 15-minute TTL. This MAY occur if a Map Request is 1486 received for a configured aggregate EID-Prefix for which no more- 1487 specific EID-Prefix exists; it indicates the presence of a non-LISP 1488 "hole" in the aggregate EID-Prefix. 1490 Next, the Map-Server checks to see if any ETRs have registered the 1491 matching EID-Prefix. If none are found, then the Map-Server returns 1492 a Negative Map-Reply with action code "Natively-Forward" and a 1493 1-minute TTL. 1495 If any of the registered ETRs for the EID-Prefix have requested proxy 1496 reply service, then the Map-Server answers the request instead of 1497 forwarding it. It returns a Map-Reply with the EID-Prefix, RLOCs, 1498 and other information learned through the registration process. 1500 If none of the ETRs have requested proxy reply service, then the Map- 1501 Server re-encapsulates and forwards the resulting Encapsulated Map- 1502 Request to one of the registered ETRs. It does not otherwise alter 1503 the Map-Request, so any Map-Reply sent by the ETR is returned to the 1504 RLOC in the Map-Request, not to the Map-Server. Unless also acting 1505 as a Map-Resolver, a Map-Server SHOULD never receive Map-Replies; any 1506 such messages SHOULD be discarded without response, perhaps 1507 accompanied by the logging of a diagnostic message if the rate of 1508 Map-Replies is suggestive of malicious traffic. 1510 8.4. Map-Resolver Processing 1512 Upon receipt of an Encapsulated Map-Request, a Map-Resolver 1513 decapsulates the enclosed message and then searches for the requested 1514 EID in its local database of mapping entries (statically configured 1515 or learned from associated ETRs if the Map-Resolver is also a Map- 1516 Server offering proxy reply service). If it finds a matching entry, 1517 it returns a LISP Map-Reply with the known mapping. 1519 If the Map-Resolver does not have the mapping entry and if it can 1520 determine that the EID is not in the mapping database (for example, 1521 if LISP-ALT is used, the Map-Resolver will have an ALT forwarding 1522 table that covers the full EID space), it immediately returns a 1523 negative LISP Map-Reply, with action code "Natively-Forward" and a 1524 15-minute TTL. To minimize the number of negative cache entries 1525 needed by an ITR, the Map-Resolver SHOULD return the least-specific 1526 prefix that both matches the original query and does not match any 1527 EID-Prefix known to exist in the LISP-capable infrastructure. 1529 If the Map-Resolver does not have sufficient information to know 1530 whether the EID exists, it needs to forward the Map-Request to 1531 another device that has more information about the EID being 1532 requested. To do this, it forwards the unencapsulated Map-Request, 1533 with the original ITR RLOC as the source, to the mapping database 1534 system. Using LISP-ALT, the Map-Resolver is connected to the ALT 1535 network and sends the Map-Request to the next ALT hop learned from 1536 its ALT BGP neighbors. The Map-Resolver does not send any response 1537 to the ITR; since the source RLOC is that of the ITR, the ETR or Map- 1538 Server that receives the Map-Request over the ALT and responds will 1539 do so directly to the ITR. 1541 8.4.1. Anycast Map-Resolver Operation 1543 A Map-Resolver can be set up to use "anycast", where the same address 1544 is assigned to multiple Map-Resolvers and is propagated through IGP 1545 routing, to facilitate the use of a topologically close Map-Resolver 1546 by each ITR. 1548 Note that Map-Server associations with ETRs SHOULD NOT use anycast 1549 addresses, as registrations need to be established between an ETR and 1550 a specific set of Map-Servers, each identified by a specific 1551 registration association. 1553 9. Security Considerations 1555 The 2-way LISP header nonce exchange documented in 1556 [I-D.ietf-lisp-rfc6830bis] can be used to avoid ITR spoofing attacks. 1558 To publish an authoritative EID-to-RLOC mapping with a Map-Server, an 1559 ETR includes authentication data that is a hash of the message using 1560 a pair-wise shared key. An implementation MUST support use of HMAC- 1561 SHA-1-96 [RFC2104] and SHOULD support use of HMAC-SHA-256-128 1562 [RFC6234] (SHA-256 truncated to 128 bits). 1564 As noted in Section 8.2, a Map-Server SHOULD verify that all EID- 1565 Prefixes registered by an ETR match the configuration stored on the 1566 Map-Server. 1568 The currently defined authentication mechanism for Map-Register 1569 messages does not provide protection against "replay" attacks by a 1570 "man-in-the-middle". Additional work is needed in this area. 1572 [I-D.ietf-lisp-sec] defines a proposed mechanism for providing origin 1573 authentication, integrity, anti-replay protection, and prevention of 1574 man-in-the-middle and "overclaiming" attacks on the Map-Request/Map- 1575 Reply exchange. Work is ongoing on this and other proposals for 1576 resolving these open security issues. 1578 While beyond the scope of securing an individual Map-Server or Map- 1579 Resolver, it SHOULD be noted that a BGP-based LISP-ALT network (if 1580 ALT is used as the mapping database infrastructure) can take 1581 advantage of standards work on adding security to BGP. 1583 A complete LISP threat analysis has been published in [RFC7835]. 1584 Please refer to it for more security related details. 1586 10. IANA Considerations 1588 This section provides guidance to the Internet Assigned Numbers 1589 Authority (IANA) regarding registration of values related to this 1590 LISP Control-Plane specification, in accordance with BCP 26 1591 [RFC8126]. 1593 There are three namespaces (listed in the sub-sections below) in LISP 1594 that have been registered. 1596 o LISP IANA registry allocations SHOULD NOT be made for purposes 1597 unrelated to LISP routing or transport protocols. 1599 o The following policies are used here with the meanings defined in 1600 BCP 26: "Specification Required", "IETF Review", "Experimental 1601 Use", and "First Come First Served". 1603 10.1. LISP UDP Port Numbers 1605 The IANA registry has allocated UDP port number 4342 for the LISP 1606 Control-Plane. IANA has updated the description for UDP port 4342 as 1607 follows: 1609 Keyword Port Transport Layer Description 1610 ------- ---- --------------- ----------- 1611 lisp-control 4342 udp LISP Control Packets 1613 10.2. LISP Packet Type Codes 1615 It is being requested that the IANA be authoritative for LISP Packet 1616 Type definitions and that it refers to this document as well as 1617 [RFC8113] as references. 1619 Based on deployment experience of [RFC6830], the Map-Notify-Ack 1620 message, message type 5, was added to this document. This document 1621 requests IANA to add it to the LISP Packet Type Registry. 1623 Name Number Defined in 1624 ---- ------ ----------- 1625 LISP Map-Notify-Ack 5 RFC6833bis 1627 10.3. LISP ACT and Flag Fields 1629 New ACT values can be allocated through IETF review or IESG approval. 1630 Four values have already been allocated by [RFC6830]. This 1631 specification changes the name of ACT type 3 value from "Drop" to 1632 "Drop/No-Reason" as well as adding two new ACT values, the "Drop/ 1633 Policy-Denied" (type 4) and "Drop/Authentication-Failure" (type 5). 1635 Value Action Description Reference 1636 ----- ------ ----------- --------- 1637 4 Drop/ A Packet matching this Map-Cache RFC6833bis 1638 Policy-Denied entry is dropped because the target 1639 EID is policy-denied by the xTR or 1640 the mapping system. 1641 5 Drop/ A Packet matching this Map-Cache RFC6833bis 1642 Auth-Failure entry is dropped because the 1643 Map-Request for target EID fails an 1644 authentication check by the xTR or 1645 the mapping system. 1647 In addition, LISP has a number of flag fields and reserved fields, 1648 such as the LISP header flags field [I-D.ietf-lisp-rfc6830bis]. New 1649 bits for flags in these fields can be implemented after IETF review 1650 or IESG approval, but these need not be managed by IANA. 1652 10.4. LISP Address Type Codes 1654 LISP Canonical Address Format (LCAF) [RFC8060] is an 8-bit field that 1655 defines LISP-specific encodings for AFI value 16387. LCAF encodings 1656 are used for specific use-cases where different address types for 1657 EID-records and RLOC-records are required. 1659 The IANA registry "LISP Canonical Address Format (LCAF) Types" is 1660 used for LCAF types, the registry for LCAF types use the 1661 Specification Required policy [RFC8126]. Initial values for the 1662 registry as well as further information can be found in [RFC8060]. 1664 Therefore, there is no longer a need for the "LISP Address Type 1665 Codes" registry requested by [RFC6830]. This document requests to 1666 remove it. 1668 10.5. LISP Algorithm ID Numbers 1670 In [RFC6830], a request for a "LISP Key ID Numbers" registry was 1671 submitted. This document renames the registry to "LISP Algorithm ID 1672 Numbers" and requests the IANA to make the name change. 1674 The following Algorithm ID values are defined by this specification 1675 as used in any packet type that references a 'Algorithm ID' field: 1677 Name Number Defined in 1678 ----------------------------------------------- 1679 None 0 RFC6833bis 1680 HMAC-SHA-1-96 1 [RFC2404] 1681 HMAC-SHA-256-128 2 [RFC4868] 1683 Number values are in the range of 0 to 255. The allocation of values 1684 is on a first come first served basis. 1686 11. References 1688 11.1. Normative References 1690 [RFC1071] Braden, R., Borman, D., and C. Partridge, "Computing the 1691 Internet checksum", RFC 1071, DOI 10.17487/RFC1071, 1692 September 1988, . 1694 [RFC2404] Madson, C. and R. Glenn, "The Use of HMAC-SHA-1-96 within 1695 ESP and AH", RFC 2404, DOI 10.17487/RFC2404, November 1696 1998, . 1698 [RFC4086] Eastlake 3rd, D., Schiller, J., and S. Crocker, 1699 "Randomness Requirements for Security", BCP 106, RFC 4086, 1700 DOI 10.17487/RFC4086, June 2005, 1701 . 1703 [RFC4868] Kelly, S. and S. Frankel, "Using HMAC-SHA-256, HMAC-SHA- 1704 384, and HMAC-SHA-512 with IPsec", RFC 4868, 1705 DOI 10.17487/RFC4868, May 2007, 1706 . 1708 [RFC6830] Farinacci, D., Fuller, V., Meyer, D., and D. Lewis, "The 1709 Locator/ID Separation Protocol (LISP)", RFC 6830, 1710 DOI 10.17487/RFC6830, January 2013, 1711 . 1713 [RFC6831] Farinacci, D., Meyer, D., Zwiebel, J., and S. Venaas, "The 1714 Locator/ID Separation Protocol (LISP) for Multicast 1715 Environments", RFC 6831, DOI 10.17487/RFC6831, January 1716 2013, . 1718 [RFC6834] Iannone, L., Saucez, D., and O. Bonaventure, "Locator/ID 1719 Separation Protocol (LISP) Map-Versioning", RFC 6834, 1720 DOI 10.17487/RFC6834, January 2013, 1721 . 1723 [RFC6836] Fuller, V., Farinacci, D., Meyer, D., and D. Lewis, 1724 "Locator/ID Separation Protocol Alternative Logical 1725 Topology (LISP+ALT)", RFC 6836, DOI 10.17487/RFC6836, 1726 January 2013, . 1728 [RFC6837] Lear, E., "NERD: A Not-so-novel Endpoint ID (EID) to 1729 Routing Locator (RLOC) Database", RFC 6837, 1730 DOI 10.17487/RFC6837, January 2013, 1731 . 1733 [RFC7215] Jakab, L., Cabellos-Aparicio, A., Coras, F., Domingo- 1734 Pascual, J., and D. Lewis, "Locator/Identifier Separation 1735 Protocol (LISP) Network Element Deployment 1736 Considerations", RFC 7215, DOI 10.17487/RFC7215, April 1737 2014, . 1739 [RFC8060] Farinacci, D., Meyer, D., and J. Snijders, "LISP Canonical 1740 Address Format (LCAF)", RFC 8060, DOI 10.17487/RFC8060, 1741 February 2017, . 1743 [RFC8111] Fuller, V., Lewis, D., Ermagan, V., Jain, A., and A. 1744 Smirnov, "Locator/ID Separation Protocol Delegated 1745 Database Tree (LISP-DDT)", RFC 8111, DOI 10.17487/RFC8111, 1746 May 2017, . 1748 [RFC8113] Boucadair, M. and C. Jacquenet, "Locator/ID Separation 1749 Protocol (LISP): Shared Extension Message & IANA Registry 1750 for Packet Type Allocations", RFC 8113, 1751 DOI 10.17487/RFC8113, March 2017, 1752 . 1754 11.2. Informative References 1756 [AFI] IANA, "Address Family Identifier (AFIs)", ADDRESS FAMILY 1757 NUMBERS http://www.iana.org/assignments/address-family- 1758 numbers/address-family-numbers.xhtml?, Febuary 2007. 1760 [I-D.ermagan-lisp-nat-traversal] 1761 Ermagan, V., Farinacci, D., Lewis, D., Skriver, J., Maino, 1762 F., and C. White, "NAT traversal for LISP", draft-ermagan- 1763 lisp-nat-traversal-13 (work in progress), September 2017. 1765 [I-D.herbert-intarea-ila] 1766 Herbert, T. and P. Lapukhov, "Identifier-locator 1767 addressing for IPv6", draft-herbert-intarea-ila-01 (work 1768 in progress), March 2018. 1770 [I-D.ietf-lisp-eid-mobility] 1771 Portoles-Comeras, M., Ashtaputre, V., Moreno, V., Maino, 1772 F., and D. Farinacci, "LISP L2/L3 EID Mobility Using a 1773 Unified Control Plane", draft-ietf-lisp-eid-mobility-01 1774 (work in progress), November 2017. 1776 [I-D.ietf-lisp-introduction] 1777 Cabellos-Aparicio, A. and D. Saucez, "An Architectural 1778 Introduction to the Locator/ID Separation Protocol 1779 (LISP)", draft-ietf-lisp-introduction-13 (work in 1780 progress), April 2015. 1782 [I-D.ietf-lisp-mn] 1783 Farinacci, D., Lewis, D., Meyer, D., and C. White, "LISP 1784 Mobile Node", draft-ietf-lisp-mn-01 (work in progress), 1785 October 2017. 1787 [I-D.ietf-lisp-rfc6830bis] 1788 Farinacci, D., Fuller, V., Meyer, D., Lewis, D., and A. 1789 Cabellos-Aparicio, "The Locator/ID Separation Protocol 1790 (LISP)", draft-ietf-lisp-rfc6830bis-11 (work in progress), 1791 March 2018. 1793 [I-D.ietf-lisp-sec] 1794 Maino, F., Ermagan, V., Cabellos-Aparicio, A., and D. 1795 Saucez, "LISP-Security (LISP-SEC)", draft-ietf-lisp-sec-14 1796 (work in progress), October 2017. 1798 [I-D.ietf-lisp-signal-free-multicast] 1799 Moreno, V. and D. Farinacci, "Signal-Free LISP Multicast", 1800 draft-ietf-lisp-signal-free-multicast-09 (work in 1801 progress), March 2018. 1803 [I-D.ietf-opsec-icmp-filtering] 1804 Gont, F., Gont, G., and C. Pignataro, "Recommendations for 1805 filtering ICMP messages", draft-ietf-opsec-icmp- 1806 filtering-04 (work in progress), July 2013. 1808 [I-D.lewis-lisp-gpe] 1809 Lewis, D., Lemon, J., Agarwal, P., Kreeger, L., Quinn, P., 1810 Smith, M., Yadav, N., and F. Maino, "LISP Generic Protocol 1811 Extension", draft-lewis-lisp-gpe-04 (work in progress), 1812 December 2017. 1814 [I-D.meyer-loc-id-implications] 1815 Meyer, D. and D. Lewis, "Architectural Implications of 1816 Locator/ID Separation", draft-meyer-loc-id-implications-01 1817 (work in progress), January 2009. 1819 [I-D.quinn-vxlan-gpe] 1820 Quinn, P., Manur, R., Kreeger, L., Lewis, D., Maino, F., 1821 Smith, M., Agarwal, P., Yong, L., Xu, X., Elzur, U., Garg, 1822 P., and D. Melman, "Generic Protocol Extension for VXLAN", 1823 draft-quinn-vxlan-gpe-04 (work in progress), February 1824 2015. 1826 [I-D.rodrigueznatal-lisp-pubsub] 1827 Rodriguez-Natal, A., Ermagan, V., Leong, J., Maino, F., 1828 Cabellos-Aparicio, A., Barkai, S., Farinacci, D., 1829 Boucadair, M., Jacquenet, C., and s. 1830 stefano.secci@lip6.fr, "Publish/Subscribe Functionality 1831 for LISP", draft-rodrigueznatal-lisp-pubsub-02 (work in 1832 progress), March 2018. 1834 [RFC1035] Mockapetris, P., "Domain names - implementation and 1835 specification", STD 13, RFC 1035, DOI 10.17487/RFC1035, 1836 November 1987, . 1838 [RFC2104] Krawczyk, H., Bellare, M., and R. Canetti, "HMAC: Keyed- 1839 Hashing for Message Authentication", RFC 2104, 1840 DOI 10.17487/RFC2104, February 1997, 1841 . 1843 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 1844 Requirement Levels", BCP 14, RFC 2119, 1845 DOI 10.17487/RFC2119, March 1997, 1846 . 1848 [RFC6234] Eastlake 3rd, D. and T. Hansen, "US Secure Hash Algorithms 1849 (SHA and SHA-based HMAC and HKDF)", RFC 6234, 1850 DOI 10.17487/RFC6234, May 2011, 1851 . 1853 [RFC6832] Lewis, D., Meyer, D., Farinacci, D., and V. Fuller, 1854 "Interworking between Locator/ID Separation Protocol 1855 (LISP) and Non-LISP Sites", RFC 6832, 1856 DOI 10.17487/RFC6832, January 2013, 1857 . 1859 [RFC7348] Mahalingam, M., Dutt, D., Duda, K., Agarwal, P., Kreeger, 1860 L., Sridhar, T., Bursell, M., and C. Wright, "Virtual 1861 eXtensible Local Area Network (VXLAN): A Framework for 1862 Overlaying Virtualized Layer 2 Networks over Layer 3 1863 Networks", RFC 7348, DOI 10.17487/RFC7348, August 2014, 1864 . 1866 [RFC7835] Saucez, D., Iannone, L., and O. Bonaventure, "Locator/ID 1867 Separation Protocol (LISP) Threat Analysis", RFC 7835, 1868 DOI 10.17487/RFC7835, April 2016, 1869 . 1871 [RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for 1872 Writing an IANA Considerations Section in RFCs", BCP 26, 1873 RFC 8126, DOI 10.17487/RFC8126, June 2017, 1874 . 1876 Appendix A. Acknowledgments 1878 The authors would like to thank Greg Schudel, Darrel Lewis, John 1879 Zwiebel, Andrew Partan, Dave Meyer, Isidor Kouvelas, Jesper Skriver, 1880 Fabio Maino, and members of the lisp@ietf.org mailing list for their 1881 feedback and helpful suggestions. 1883 Special thanks are due to Noel Chiappa for his extensive work and 1884 thought about caching in Map-Resolvers. 1886 Appendix B. Document Change Log 1888 [RFC Editor: Please delete this section on publication as RFC.] 1890 B.1. Changes to draft-ietf-lisp-rfc6833bis-09 1892 o Posted March IETF week 2018. 1894 o Fixed editorial comments submitted by document shepherd Luigi 1895 Iannone. 1897 B.2. Changes to draft-ietf-lisp-rfc6833bis-08 1899 o Posted March 2018. 1901 o Added RLOC-probing algorithm. 1903 o Added Solicit-Map Request algorithm. 1905 o Added several mechanisms (from 6830bis) regarding Routing Locator 1906 Reachability. 1908 o Added port 4342 to IANA Considerations section. 1910 B.3. Changes to draft-ietf-lisp-rfc6833bis-07 1912 o Posted December 2017. 1914 o Make it more clear in a couple of places that RLOCs are used to 1915 locate ETRs more so than for Map-Server Map-Request forwarding. 1917 o Make it clear that "encapsualted" for a control message is an ECM 1918 based message. 1920 o Make it more clear what messages use source-port 4342 and which 1921 ones use destinatino-port 4342. 1923 o Don't make DDT references when the mapping transport system can be 1924 of any type and the referneced text is general to it. 1926 o Generalize text when referring to the format of an EID-prefix. 1927 Can use othe AFIs then IPv4 and IPv6. 1929 o Many editorial changes to clarify text. 1931 o Changed some "must", "should", and "may" to capitalized. 1933 o Added definitions for Map-Request and Map-Reply messages. 1935 o Ran document through IDNITs. 1937 B.4. Changes to draft-ietf-lisp-rfc6833bis-06 1939 o Posted October 2017. 1941 o Spec the I-bit to include the xTR-ID in a Map-Request message to 1942 be consistent with the Map-Register message and to anticipate the 1943 introduction of pubsub functionality to allow Map-Requests to 1944 subscribe to RLOC-set changes. 1946 o Updated references for individual submissions that became working 1947 group documents. 1949 o Updated references for working group documents that became RFCs. 1951 B.5. Changes to draft-ietf-lisp-rfc6833bis-05 1953 o Posted May 2017. 1955 o Update IANA Considerations section based on new requests from this 1956 document and changes from what was requested in [RFC6830]. 1958 B.6. Changes to draft-ietf-lisp-rfc6833bis-04 1960 o Posted May 2017. 1962 o Clarify how the Key-ID field is used in Map-Register and Map- 1963 Notify messages. Break the 16-bit field into a 8-bit Key-ID field 1964 and a 8-bit Algorithm-ID field. 1966 o Move the Control-Plane codepoints from the IANA Considerations 1967 section of RFC6830bis to the IANA Considerations section of this 1968 document. 1970 o In the "LISP Control Packet Type Allocations" section, indicate 1971 how message Types are IANA allocated and how experimental RFC8113 1972 sub-types should be requested. 1974 B.7. Changes to draft-ietf-lisp-rfc6833bis-03 1976 o Posted April 2017. 1978 o Add types 9-14 and specify they are not assigned. 1980 o Add the "LISP Shared Extension Message" type and point to RFC8113. 1982 B.8. Changes to draft-ietf-lisp-rfc6833bis-02 1984 o Posted April 2017. 1986 o Clarify that the LISP Control-Plane document defines how the LISP 1987 Data-Plane uses Map-Requests with either the SMR-bit set or the 1988 P-bit set supporting mapping updates and RLOC-probing. Indicating 1989 that other Data-Planes can use the same mechanisms or their own 1990 defined mechanisms to achieve the same functionality. 1992 B.9. Changes to draft-ietf-lisp-rfc6833bis-01 1994 o Posted March 2017. 1996 o Include references to new RFCs published. 1998 o Remove references to self. 2000 o Change references from RFC6830 to RFC6830bis. 2002 o Add two new action/reasons to a Map-Reply has posted to the LISP 2003 WG mailing list. 2005 o In intro section, add refernece to I-D.ietf-lisp-introduction. 2007 o Removed Open Issues section and references to "experimental". 2009 B.10. Changes to draft-ietf-lisp-rfc6833bis-00 2011 o Posted December 2016. 2013 o Created working group document from draft-farinacci-lisp 2014 -rfc6833-00 individual submission. No other changes made. 2016 B.11. Changes to draft-farinacci-lisp-rfc6833bis-00 2018 o Posted November 2016. 2020 o This is the initial draft to turn RFC 6833 into RFC 6833bis. 2022 o The document name has changed from the "Locator/ID Separation 2023 Protocol (LISP) Map-Server Interface" to the "Locator/ID 2024 Separation Protocol (LISP) Control-Plane". 2026 o The fundamental change was to move the Control-Plane messages from 2027 RFC 6830 to this document in an effort so any IETF developed or 2028 industry created Data-Plane could use the LISP mapping system and 2029 Control-Plane. 2031 o Update Control-Plane messages to incorporate what has been 2032 implemented in products during the early phase of LISP development 2033 but wasn't able to make it into RFC6830 and RFC6833 to make the 2034 Experimental RFC deadline. 2036 o Indicate there may be nodes in the mapping system that are not MRs 2037 or MSs, that is a ALT-node or a DDT-node. 2039 o Include LISP-DDT in Map-Resolver section and explain how they 2040 maintain a referral-cache. 2042 o Removed open issue about additional state in Map-Servers. With 2043 [RFC8111], Map-Servers have the same registration state and can 2044 give Map-Resolvers complete information in ms-ack Map-Referral 2045 messages. 2047 o Make reference to the LISP Threats Analysis RFC [RFC7835]. 2049 Authors' Addresses 2051 Vince Fuller 2052 Cisco Systems 2054 EMail: vaf@vaf.net 2056 Dino Farinacci 2057 Cisco Systems 2059 EMail: farinacci@gmail.com 2060 Albert Cabellos 2061 UPC/BarcelonaTech 2062 Campus Nord, C. Jordi Girona 1-3 2063 Barcelona, Catalunya 2064 Spain 2066 EMail: acabello@ac.upc.edu