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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: November 5, 2017 A. Cabellos (Ed.) 6 UPC/BarcelonaTech 7 May 4, 2017 9 Locator/ID Separation Protocol (LISP) Control-Plane 10 draft-ietf-lisp-rfc6833bis-04 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 infrastructure, connect directly to LISP-capable Internet end 26 sites, and comprise the bulk of LISP-speaking devices, reducing their 27 implementation and operational complexity should also reduce the 28 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 http://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 November 5, 2017. 47 Copyright Notice 49 Copyright (c) 2017 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 (http://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. Definition of Terms . . . . . . . . . . . . . . . . . . . . . 4 66 3. Basic Overview . . . . . . . . . . . . . . . . . . . . . . . 5 67 4. LISP IPv4 and IPv6 Control-Plane Packet Formats . . . . . . . 7 68 4.1. LISP Control Packet Type Allocations . . . . . . . . . . 9 69 4.2. Map-Request Message Format . . . . . . . . . . . . . . . 10 70 4.3. EID-to-RLOC UDP Map-Request Message . . . . . . . . . . . 12 71 4.4. Map-Reply Message Format . . . . . . . . . . . . . . . . 14 72 4.5. EID-to-RLOC UDP Map-Reply Message . . . . . . . . . . . . 18 73 4.6. Map-Register Message Format . . . . . . . . . . . . . . . 21 74 4.7. Map-Notify/Map-Notify-Ack Message Format . . . . . . . . 24 75 4.8. Encapsulated Control Message Format . . . . . . . . . . . 25 76 5. Interactions with Other LISP Components . . . . . . . . . . . 27 77 5.1. ITR EID-to-RLOC Mapping Resolution . . . . . . . . . . . 27 78 5.2. EID-Prefix Configuration and ETR Registration . . . . . . 28 79 5.3. Map-Server Processing . . . . . . . . . . . . . . . . . . 30 80 5.4. Map-Resolver Processing . . . . . . . . . . . . . . . . . 30 81 5.4.1. Anycast Map-Resolver Operation . . . . . . . . . . . 31 82 6. Security Considerations . . . . . . . . . . . . . . . . . . . 31 83 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 32 84 7.1. LISP Packet Type Codes . . . . . . . . . . . . . . . . . 32 85 7.2. LISP ACT and Flag Fields . . . . . . . . . . . . . . . . 32 86 7.3. LISP Address Type Codes . . . . . . . . . . . . . . . . . 33 87 7.4. LISP Algorithm ID Numbers . . . . . . . . . . . . . . . . 33 88 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 33 89 8.1. Normative References . . . . . . . . . . . . . . . . . . 33 90 8.2. Informative References . . . . . . . . . . . . . . . . . 35 91 Appendix A. Acknowledgments . . . . . . . . . . . . . . . . . . 37 92 Appendix B. Document Change Log . . . . . . . . . . . . . . . . 37 93 B.1. Changes to draft-ietf-lisp-rfc6833bis-04 . . . . . . . . 37 94 B.2. Changes to draft-ietf-lisp-rfc6833bis-03 . . . . . . . . 37 95 B.3. Changes to draft-ietf-lisp-rfc6833bis-02 . . . . . . . . 37 96 B.4. Changes to draft-ietf-lisp-rfc6833bis-01 . . . . . . . . 38 97 B.5. Changes to draft-ietf-lisp-rfc6833bis-00 . . . . . . . . 38 98 B.6. Changes to draft-farinacci-lisp-rfc6833bis-00 . . . . . . 38 99 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 39 101 1. Introduction 103 The Locator/ID Separation Protocol [I-D.ietf-lisp-introduction] and 104 [I-D.ietf-lisp-rfc6830bis] specifies an architecture and mechanism 105 for replacing the addresses currently used by IP with two separate 106 name spaces: Endpoint IDs (EIDs), used within sites; and Routing 107 Locators (RLOCs), used on the transit networks that make up the 108 Internet infrastructure. To achieve this separation, LISP defines 109 protocol mechanisms for mapping from EIDs to RLOCs. In addition, 110 LISP assumes the existence of a database to store and propagate those 111 mappings globally. Several such databases have been proposed; among 112 them are the Content distribution Overlay Network Service for LISP 113 (LISP-CONS) [LISP-CONS], LISP-NERD (a Not-so-novel EID-to-RLOC 114 Database) [RFC6837], LISP Alternative Logical Topology (LISP+ALT) 115 [RFC6836], and LISP Delegated Database Tree (LISP-DDT) 116 [I-D.ietf-lisp-ddt]. 118 The LISP Mapping Service defines two new types of LISP-speaking 119 devices: the Map-Resolver, which accepts Map-Requests from an Ingress 120 Tunnel Router (ITR) and "resolves" the EID-to-RLOC mapping using a 121 mapping database; and the Map-Server, which learns authoritative EID- 122 to-RLOC mappings from an Egress Tunnel Router (ETR) and publishes 123 them in a database. 125 This LISP Control-Plane Mapping Service can be used by many different 126 encapsulation-based or translation-based data-planes which include 127 but are not limited to the ones defined in LISP RFC 6830bis 128 [I-D.ietf-lisp-rfc6830bis], LISP-GPE [I-D.lewis-lisp-gpe], VXLAN 129 [RFC7348], and VXLAN-GPE [I-D.quinn-vxlan-gpe]. 131 Conceptually, LISP Map-Servers share some of the same basic 132 configuration and maintenance properties as Domain Name System (DNS) 133 [RFC1035] servers; likewise, Map-Resolvers are conceptually similar 134 to DNS caching resolvers. With this in mind, this specification 135 borrows familiar terminology (resolver and server) from the DNS 136 specifications. 138 Note that while this document assumes a LISP+ALT database mapping 139 infrastructure to illustrate certain aspects of Map-Server and Map- 140 Resolver operation, the Mapping Service interface can (and likely 141 will) be used by ITRs and ETRs to access other mapping database 142 systems as the LISP infrastructure evolves. 144 The LISP Mapping Service is an important component of the LISP 145 toolset. Issues and concerns about the deployment of LISP for 146 Internet traffic are discussed in [I-D.ietf-lisp-rfc6830bis]. 148 2. Definition of Terms 150 Map-Server: A network infrastructure component that learns of EID- 151 Prefix mapping entries from an ETR, via the registration mechanism 152 described below, or some other authoritative source if one exists. 153 A Map-Server publishes these EID-Prefixes in a mapping database. 155 Map-Resolver: A network infrastructure component that accepts LISP 156 Encapsulated Map-Requests, typically from an ITR, and determines 157 whether or not the destination IP address is part of the EID 158 namespace; if it is not, a Negative Map-Reply is returned. 159 Otherwise, the Map-Resolver finds the appropriate EID-to-RLOC 160 mapping by consulting a mapping database system. 162 Encapsulated Map-Request: A LISP Map-Request carried within an 163 Encapsulated Control Message, which has an additional LISP header 164 prepended. Sent to UDP destination port 4342. The "outer" 165 addresses are globally routable IP addresses, also known as RLOCs. 166 Used by an ITR when sending to a Map-Resolver and by a Map-Server 167 when forwarding a Map-Request to an ETR. 169 Negative Map-Reply: A LISP Map-Reply that contains an empty 170 Locator-Set. Returned in response to a Map-Request if the 171 destination EID does not exist in the mapping database. 172 Typically, this means that the "EID" being requested is an IP 173 address connected to a non-LISP site. 175 Map-Register message: A LISP message sent by an ETR to a Map-Server 176 to register its associated EID-Prefixes. In addition to the set 177 of EID-Prefixes to register, the message includes one or more 178 RLOCs to be used by the Map-Server when forwarding Map-Requests 179 (re-formatted as Encapsulated Map-Requests) received through the 180 database mapping system. An ETR may request that the Map-Server 181 answer Map-Requests on its behalf by setting the "proxy Map-Reply" 182 flag (P-bit) in the message. 184 Map-Notify message: A LISP message sent by a Map-Server to an ETR 185 to confirm that a Map-Register has been received and processed. 186 An ETR requests that a Map-Notify be returned by setting the 187 "want-map-notify" flag (M-bit) in the Map-Register message. 188 Unlike a Map-Reply, a Map-Notify uses UDP port 4342 for both 189 source and destination. 191 For definitions of other terms -- notably Map-Request, Map-Reply, 192 Ingress Tunnel Router (ITR), and Egress Tunnel Router (ETR) -- please 193 consult the LISP specification [I-D.ietf-lisp-rfc6830bis]. 195 3. Basic Overview 197 A Map-Server is a device that publishes EID-Prefixes in a LISP 198 mapping database on behalf of a set of ETRs. When it receives a Map 199 Request (typically from an ITR), it consults the mapping database to 200 find an ETR that can answer with the set of RLOCs for an EID-Prefix. 201 To publish its EID-Prefixes, an ETR periodically sends Map-Register 202 messages to the Map-Server. A Map-Register message contains a list 203 of EID-Prefixes plus a set of RLOCs that can be used to reach the ETR 204 when a Map-Server needs to forward a Map-Request to it. 206 When LISP+ALT is used as the mapping database, a Map-Server connects 207 to the ALT network and acts as a "last-hop" ALT-Router. Intermediate 208 ALT-Routers forward Map-Requests to the Map-Server that advertises a 209 particular EID-Prefix, and the Map-Server forwards them to the owning 210 ETR, which responds with Map-Reply messages. 212 When LISP-DDT [I-D.ietf-lisp-ddt] is used as the mapping database, a 213 Map-Server sends the final Map-Referral messages from the Delegated 214 Database Tree. 216 A Map-Resolver receives Encapsulated Map-Requests from its client 217 ITRs and uses a mapping database system to find the appropriate ETR 218 to answer those requests. On a LISP+ALT network, a Map-Resolver acts 219 as a "first-hop" ALT-Router. It has Generic Routing Encapsulation 220 (GRE) tunnels configured to other ALT-Routers and uses BGP to learn 221 paths to ETRs for different prefixes in the LISP+ALT database. The 222 Map-Resolver uses this path information to forward Map-Requests over 223 the ALT to the correct ETRs. On a LISP-DDT network 224 [I-D.ietf-lisp-ddt], a Map-Resolver maintains a referral-cache and 225 acts as a "first-hop" DDT-node. The Map-Resolver uses the referral 226 information to forward Map-Requests. 228 Note that while it is conceivable that a non-LISP-DDT Map-Resolver 229 could cache responses to improve performance, issues surrounding 230 cache management will need to be resolved so that doing so will be 231 reliable and practical. As initially deployed, Map-Resolvers will 232 operate only in a non-caching mode, decapsulating and forwarding 233 Encapsulated Map Requests received from ITRs. Any specification of 234 caching functionality is left for future work. 236 Note that a single device can implement the functions of both a Map- 237 Server and a Map-Resolver, and in many cases the functions will be 238 co-located in that way. Also, there can be ALT-only nodes and DDT- 239 only nodes, when LISP+ALT and LISP-DDT are used, respectively, to 240 connect Map-Resolvers and Map-Servers together to make up the Mapping 241 System. 243 Detailed descriptions of the LISP packet types referenced by this 244 document may be found in [I-D.ietf-lisp-rfc6830bis]. 246 4. LISP IPv4 and IPv6 Control-Plane Packet Formats 248 The following UDP packet formats are used by the LISP control plane. 250 0 1 2 3 251 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 1 252 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 253 |Version| IHL |Type of Service| Total Length | 254 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 255 | Identification |Flags| Fragment Offset | 256 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 257 | Time to Live | Protocol = 17 | Header Checksum | 258 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 259 | Source Routing Locator | 260 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 261 | Destination Routing Locator | 262 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 263 / | Source Port | Dest Port | 264 UDP +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 265 \ | UDP Length | UDP Checksum | 266 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 267 | | 268 | LISP Message | 269 | | 270 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 272 0 1 2 3 273 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 1 274 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 275 |Version| Traffic Class | Flow Label | 276 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 277 | Payload Length | Next Header=17| Hop Limit | 278 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 279 | | 280 + + 281 | | 282 + Source Routing Locator + 283 | | 284 + + 285 | | 286 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 287 | | 288 + + 289 | | 290 + Destination Routing Locator + 291 | | 292 + + 293 | | 294 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 295 / | Source Port | Dest Port | 296 UDP +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 297 \ | UDP Length | UDP Checksum | 298 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 299 | | 300 | LISP Message | 301 | | 302 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 304 The LISP UDP-based messages are the Map-Request and Map-Reply 305 messages. When a UDP Map-Request is sent, the UDP source port is 306 chosen by the sender and the destination UDP port number is set to 307 4342. When a UDP Map-Reply is sent, the source UDP port number is 308 set to 4342 and the destination UDP port number is copied from the 309 source port of either the Map-Request or the invoking data packet. 310 Implementations MUST be prepared to accept packets when either the 311 source port or destination UDP port is set to 4342 due to NATs 312 changing port number values. 314 The 'UDP Length' field will reflect the length of the UDP header and 315 the LISP Message payload. 317 The UDP checksum is computed and set to non-zero for Map-Request, 318 Map-Reply, Map-Register, and Encapsulated Control Message (ECM) 319 control messages. It MUST be checked on receipt, and if the checksum 320 fails, the packet MUST be dropped. 322 The format of control messages includes the UDP header so the 323 checksum and length fields can be used to protect and delimit message 324 boundaries. 326 4.1. LISP Control Packet Type Allocations 328 This section defines the LISP control message formats and summarizes 329 for IANA the LISP Type codes assigned by this document. For 330 completeness, this document references the LISP Shared Extension 331 Message assigned by [RFC8113]. Message type definitions are: 333 Reserved: 0 b'0000' 334 LISP Map-Request: 1 b'0001' 335 LISP Map-Reply: 2 b'0010' 336 LISP Map-Register: 3 b'0011' 337 LISP Map-Notify: 4 b'0100' 338 LISP Map-Notify-Ack: 5 b'0101' 339 LISP Map-Referral: 6 b'0110' 340 LISP Encapsulated Control Message: 8 b'1000' 341 Not Assigned 9-14 b'1001'- b'1110' 342 LISP Shared Extension Message: 15 b'1111' [RFC8113] 344 Values in the "Not Assigned" range can be assigned according to 345 procedures in [RFC5226]. Documents that request for a new LISP 346 packet type may indicate a preferred value in Section 7.3. 348 Protocol designers experimenting with new message formats should use 349 the LISP Shared Extension Message Type and request a [RFC8113] sub- 350 type assignment. 352 All LISP control-plane messages use Address Family Identifiers (AFI) 353 [AFI] or LISP Canonical Address Format (LCAF) [RFC8060] formats to 354 encode either fixed or variable length addresses. This includes 355 explicit fields in each control message or part of EID-records or 356 RLOC-records in commonly formatted messages. 358 The LISP control-plane describes how other data-planes can encode 359 messages to support the SMR and RLOC-probing procedures of the LISP 360 data-plane defined in [I-D.ietf-lisp-rfc6830bis]. This control-plane 361 specification itself does not offer such functionality and other 362 data-planes can use their own mechanisms that do not rely on the LISP 363 control-plane. 365 4.2. Map-Request Message Format 367 0 1 2 3 368 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 1 369 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 370 |Type=1 |A|M|P|S|p|s|m| Reserved |L|D| IRC | Record Count | 371 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 372 | Nonce . . . | 373 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 374 | . . . Nonce | 375 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 376 | Source-EID-AFI | Source EID Address ... | 377 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 378 | ITR-RLOC-AFI 1 | ITR-RLOC Address 1 ... | 379 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 380 | ... | 381 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 382 | ITR-RLOC-AFI n | ITR-RLOC Address n ... | 383 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 384 / | Reserved | EID mask-len | EID-Prefix-AFI | 385 Rec +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 386 \ | EID-Prefix ... | 387 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 388 | Map-Reply Record ... | 389 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 391 Packet field descriptions: 393 Type: 1 (Map-Request) 395 A: This is an authoritative bit, which is set to 0 for UDP-based Map- 396 Requests sent by an ITR. It is set to 1 when an ITR wants the 397 destination site to return the Map-Reply rather than the mapping 398 database system. 400 M: This is the map-data-present bit. When set, it indicates that a 401 Map-Reply Record segment is included in the Map-Request. 403 P: This is the probe-bit, which indicates that a Map-Request SHOULD 404 be treated as a Locator reachability probe. The receiver SHOULD 405 respond with a Map-Reply with the probe-bit set, indicating that 406 the Map-Reply is a Locator reachability probe reply, with the 407 nonce copied from the Map-Request. See RLOC-Probing 408 [I-D.ietf-lisp-rfc6830bis] for more details. 410 S: This is the Solicit-Map-Request (SMR) bit. See Solicit-Map- 411 Request (SMRs) [I-D.ietf-lisp-rfc6830bis] for details. 413 p: This is the PITR bit. This bit is set to 1 when a PITR sends a 414 Map-Request. 416 s: This is the SMR-invoked bit. This bit is set to 1 when an xTR is 417 sending a Map-Request in response to a received SMR-based Map- 418 Request. 420 m: This is the LISP mobile-node m-bit. This bit is set by xTRs that 421 operate as a mobile node as defined in [I-D.ietf-lisp-mn]. 423 Reserved: This field MUST be set to 0 on transmit and MUST be 424 ignored on receipt. 426 L: This is the local-xtr bit. It is used by an xTR in a LISP site to 427 tell other xTRs in the same site that it is local to the site. 428 That is, that it is part of the RLOC-set for the LISP site. 430 D: This is the dont-map-reply bit. It is used in the SMR procedure 431 described in [I-D.ietf-lisp-rfc6830bis]. When an xTR sends an SMR 432 Map-Request message, it doesn't need a Map-Reply returned. When 433 this bit is set, the receiver of the Map-Request does not return a 434 Map-Reply. 436 IRC: This 5-bit field is the ITR-RLOC Count, which encodes the 437 additional number of ('ITR-RLOC-AFI', 'ITR-RLOC Address') fields 438 present in this message. At least one (ITR-RLOC-AFI, ITR-RLOC- 439 Address) pair MUST be encoded. Multiple 'ITR-RLOC Address' fields 440 are used, so a Map-Replier can select which destination address to 441 use for a Map-Reply. The IRC value ranges from 0 to 31. For a 442 value of 0, there is 1 ITR-RLOC address encoded; for a value of 1, 443 there are 2 ITR-RLOC addresses encoded, and so on up to 31, which 444 encodes a total of 32 ITR-RLOC addresses. 446 Record Count: This is the number of records in this Map-Request 447 message. A record is comprised of the portion of the packet that 448 is labeled 'Rec' above and occurs the number of times equal to 449 Record Count. For this version of the protocol, a receiver MUST 450 accept and process Map-Requests that contain one or more records, 451 but a sender MUST only send Map-Requests containing one record. 452 Support for requesting multiple EIDs in a single Map-Request 453 message will be specified in a future version of the protocol. 455 Nonce: This is an 8-octet random value created by the sender of the 456 Map-Request. This nonce will be returned in the Map-Reply. The 457 security of the LISP mapping protocol critically depends on the 458 strength of the nonce in the Map-Request message. The nonce 459 SHOULD be generated by a properly seeded pseudo-random (or strong 460 random) source. See [RFC4086] for advice on generating security- 461 sensitive random data. 463 Source-EID-AFI: This is the address family of the 'Source EID 464 Address' field. 466 Source EID Address: This is the EID of the source host that 467 originated the packet that caused the Map-Request. When Map- 468 Requests are used for refreshing a Map-Cache entry or for RLOC- 469 Probing, an AFI value 0 is used and this field is of zero length. 471 ITR-RLOC-AFI: This is the address family of the 'ITR-RLOC Address' 472 field that follows this field. 474 ITR-RLOC Address: This is used to give the ETR the option of 475 selecting the destination address from any address family for the 476 Map-Reply message. This address MUST be a routable RLOC address 477 of the sender of the Map-Request message. 479 EID mask-len: This is the mask length for the EID-Prefix. 481 EID-Prefix-AFI: This is the address family of the EID-Prefix 482 according to [AFI] and [RFC8060]. 484 EID-Prefix: This prefix is 4 octets for an IPv4 address family and 485 16 octets for an IPv6 address family. When a Map-Request is sent 486 by an ITR because a data packet is received for a destination 487 where there is no mapping entry, the EID-Prefix is set to the 488 destination IP address of the data packet, and the 'EID mask-len' 489 is set to 32 or 128 for IPv4 or IPv6, respectively. When an xTR 490 wants to query a site about the status of a mapping it already has 491 cached, the EID-Prefix used in the Map-Request has the same mask 492 length as the EID-Prefix returned from the site when it sent a 493 Map-Reply message. 495 Map-Reply Record: When the M-bit is set, this field is the size of a 496 single "Record" in the Map-Reply format. This Map-Reply record 497 contains the EID-to-RLOC mapping entry associated with the Source 498 EID. This allows the ETR that will receive this Map-Request to 499 cache the data if it chooses to do so. 501 4.3. EID-to-RLOC UDP Map-Request Message 503 A Map-Request is sent from an ITR when it needs a mapping for an EID, 504 wants to test an RLOC for reachability, or wants to refresh a mapping 505 before TTL expiration. For the initial case, the destination IP 506 address used for the Map-Request is the data packet's destination 507 address (i.e., the destination EID) that had a mapping cache lookup 508 failure. For the latter two cases, the destination IP address used 509 for the Map-Request is one of the RLOC addresses from the Locator-Set 510 of the Map-Cache entry. The source address is either an IPv4 or IPv6 511 RLOC address, depending on whether the Map-Request is using an IPv4 512 or IPv6 header, respectively. In all cases, the UDP source port 513 number for the Map-Request message is a 16-bit value selected by the 514 ITR/PITR, and the UDP destination port number is set to the well- 515 known destination port number 4342. A successful Map-Reply, which is 516 one that has a nonce that matches an outstanding Map-Request nonce, 517 will update the cached set of RLOCs associated with the EID-Prefix 518 range. 520 One or more Map-Request ('ITR-RLOC-AFI', 'ITR-RLOC-Address') fields 521 MUST be filled in by the ITR. The number of fields (minus 1) encoded 522 MUST be placed in the 'IRC' field. The ITR MAY include all locally 523 configured Locators in this list or just provide one locator address 524 from each address family it supports. If the ITR erroneously 525 provides no ITR-RLOC addresses, the Map-Replier MUST drop the Map- 526 Request. 528 Map-Requests can also be LISP encapsulated using UDP destination 529 port 4342 with a LISP Type value set to "Encapsulated Control 530 Message", when sent from an ITR to a Map-Resolver. Likewise, Map- 531 Requests are LISP encapsulated the same way from a Map-Server to an 532 ETR. Details on Encapsulated Map-Requests and Map-Resolvers can be 533 found in Section 4.8. 535 Map-Requests MUST be rate-limited. It is RECOMMENDED that a Map- 536 Request for the same EID-Prefix be sent no more than once per second. 538 An ITR that is configured with mapping database information (i.e., it 539 is also an ETR) MAY optionally include those mappings in a Map- 540 Request. When an ETR configured to accept and verify such 541 "piggybacked" mapping data receives such a Map-Request and it does 542 not have this mapping in the map-cache, it MAY originate a "verifying 543 Map-Request", addressed to the map-requesting ITR and the ETR MAY add 544 a Map-Cache entry. If the ETR has a Map-Cache entry that matches the 545 "piggybacked" EID and the RLOC is in the Locator-Set for the entry, 546 then it may send the "verifying Map-Request" directly to the 547 originating Map-Request source. If the RLOC is not in the Locator- 548 Set, then the ETR MUST send the "verifying Map-Request" to the 549 "piggybacked" EID. Doing this forces the "verifying Map-Request" to 550 go through the mapping database system to reach the authoritative 551 source of information about that EID, guarding against RLOC-spoofing 552 in the "piggybacked" mapping data. 554 4.4. Map-Reply Message Format 556 0 1 2 3 557 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 1 558 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 559 |Type=2 |P|E|S| Reserved | Record Count | 560 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 561 | Nonce . . . | 562 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 563 | . . . Nonce | 564 +-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 565 | | Record TTL | 566 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 567 R | Locator Count | EID mask-len | ACT |A| Reserved | 568 e +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 569 c | Rsvd | Map-Version Number | EID-Prefix-AFI | 570 o +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 571 r | EID-Prefix | 572 d +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 573 | /| Priority | Weight | M Priority | M Weight | 574 | L +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 575 | o | Unused Flags |L|p|R| Loc-AFI | 576 | c +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 577 | \| Locator | 578 +-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 580 Packet field descriptions: 582 Type: 2 (Map-Reply) 584 P: This is the probe-bit, which indicates that the Map-Reply is in 585 response to a Locator reachability probe Map-Request. The 'Nonce' 586 field MUST contain a copy of the nonce value from the original 587 Map-Request. See RLOC-probing [I-D.ietf-lisp-rfc6830bis] for more 588 details. 590 E: This bit indicates that the ETR that sends this Map-Reply message 591 is advertising that the site is enabled for the Echo-Nonce Locator 592 reachability algorithm. See Echo-Nonce [I-D.ietf-lisp-rfc6830bis] 593 for more details. 595 S: This is the Security bit. When set to 1, the following 596 authentication information will be appended to the end of the Map- 597 Reply. The details of signing a Map-Reply message can be found in 598 [I-D.ietf-lisp-sec]. 600 0 1 2 3 601 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 1 602 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 603 | AD Type | Authentication Data Content . . . | 604 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 606 Reserved: This field MUST be set to 0 on transmit and MUST be 607 ignored on receipt. 609 Record Count: This is the number of records in this reply message. 610 A record is comprised of that portion of the packet labeled 611 'Record' above and occurs the number of times equal to Record 612 Count. 614 Nonce: This is a 24-bit value set in a Data-Probe packet, or a 615 64-bit value from the Map-Request is echoed in this 'Nonce' field 616 of the Map-Reply. When a 24-bit value is supplied, it resides in 617 the low-order 64 bits of the 'Nonce' field. 619 Record TTL: This is the time in minutes the recipient of the Map- 620 Reply will store the mapping. If the TTL is 0, the entry SHOULD 621 be removed from the cache immediately. If the value is 622 0xffffffff, the recipient can decide locally how long to store the 623 mapping. 625 Locator Count: This is the number of Locator entries. A Locator 626 entry comprises what is labeled above as 'Loc'. The Locator count 627 can be 0, indicating that there are no Locators for the EID- 628 Prefix. 630 EID mask-len: This is the mask length for the EID-Prefix. 632 ACT: This 3-bit field describes Negative Map-Reply actions. In any 633 other message type, these bits are set to 0 and ignored on 634 receipt. These bits are used only when the 'Locator Count' field 635 is set to 0. The action bits are encoded only in Map-Reply 636 messages. The actions defined are used by an ITR or PITR when a 637 destination EID matches a negative Map-Cache entry. Unassigned 638 values should cause a Map-Cache entry to be created, and when 639 packets match this negative cache entry, they will be dropped. 640 The current assigned values are: 642 (0) No-Action: The map-cache is kept alive, and no packet 643 encapsulation occurs. 645 (1) Natively-Forward: The packet is not encapsulated or dropped 646 but natively forwarded. 648 (2) Send-Map-Request: The packet invokes sending a Map-Request. 650 (3) Drop/No-Reason: A packet that matches this map-cache entry is 651 dropped. An ICMP Destination Unreachable message SHOULD be 652 sent. 654 (4) Drop/Policy-Denied: A packet that matches this map-cache 655 entry is dropped. The reason for the Drop action is that a 656 Map-Request for the target-EID is being policy denied by 657 either an xTR or the mapping system. 659 (5) Drop/Authentication-Failure: A packet that matches this map- 660 cache entry is dropped. The reason for the Drop action is 661 that a Map-Request for the target-EID fails an authentication 662 verification-check by either an xTR or the mapping system. 664 A: The Authoritative bit, when sent, is always set to 1 by an ETR. 665 When a Map-Server is proxy Map-Replying for a LISP site, the 666 Authoritative bit is set to 0. This indicates to requesting ITRs 667 that the Map-Reply was not originated by a LISP node managed at 668 the site that owns the EID-Prefix. 670 Map-Version Number: When this 12-bit value is non-zero, the Map- 671 Reply sender is informing the ITR what the version number is for 672 the EID record contained in the Map-Reply. The ETR can allocate 673 this number internally but MUST coordinate this value with other 674 ETRs for the site. When this value is 0, there is no versioning 675 information conveyed. The Map-Version Number can be included in 676 Map-Request and Map-Register messages. See Map-Versioning 677 [I-D.ietf-lisp-rfc6830bis] for more details. 679 EID-Prefix-AFI: Address family of the EID-Prefix according to [AFI] 680 and [RFC8060]. 682 EID-Prefix: This prefix is 4 octets for an IPv4 address family and 683 16 octets for an IPv6 address family. 685 Priority: Each RLOC is assigned a unicast Priority. Lower values 686 are more preferable. When multiple RLOCs have the same Priority, 687 they MAY be used in a load-split fashion. A value of 255 means 688 the RLOC MUST NOT be used for unicast forwarding. 690 Weight: When priorities are the same for multiple RLOCs, the Weight 691 indicates how to balance unicast traffic between them. Weight is 692 encoded as a relative weight of total unicast packets that match 693 the mapping entry. For example, if there are 4 Locators in a 694 Locator-Set, where the Weights assigned are 30, 20, 20, and 10, 695 the first Locator will get 37.5% of the traffic, the 2nd and 3rd 696 Locators will get 25% of the traffic, and the 4th Locator will get 697 12.5% of the traffic. If all Weights for a Locator-Set are equal, 698 the receiver of the Map-Reply will decide how to load-split the 699 traffic. See RLOC-hashing [I-D.ietf-lisp-rfc6830bis] for a 700 suggested hash algorithm to distribute the load across Locators 701 with the same Priority and equal Weight values. 703 M Priority: Each RLOC is assigned a multicast Priority used by an 704 ETR in a receiver multicast site to select an ITR in a source 705 multicast site for building multicast distribution trees. A value 706 of 255 means the RLOC MUST NOT be used for joining a multicast 707 distribution tree. For more details, see [RFC6831]. 709 M Weight: When priorities are the same for multiple RLOCs, the 710 Weight indicates how to balance building multicast distribution 711 trees across multiple ITRs. The Weight is encoded as a relative 712 weight (similar to the unicast Weights) of the total number of 713 trees built to the source site identified by the EID-Prefix. If 714 all Weights for a Locator-Set are equal, the receiver of the Map- 715 Reply will decide how to distribute multicast state across ITRs. 716 For more details, see [RFC6831]. 718 Unused Flags: These are set to 0 when sending and ignored on 719 receipt. 721 L: When this bit is set, the Locator is flagged as a local Locator to 722 the ETR that is sending the Map-Reply. When a Map-Server is doing 723 proxy Map-Replying for a LISP site, the L-bit is set to 0 for all 724 Locators in this Locator-Set. 726 p: When this bit is set, an ETR informs the RLOC-Probing ITR that the 727 locator address for which this bit is set is the one being RLOC- 728 probed and MAY be different from the source address of the Map- 729 Reply. An ITR that RLOC-probes a particular Locator MUST use this 730 Locator for retrieving the data structure used to store the fact 731 that the Locator is reachable. The p-bit is set for a single 732 Locator in the same Locator-Set. If an implementation sets more 733 than one p-bit erroneously, the receiver of the Map-Reply MUST 734 select the first Locator. The p-bit MUST NOT be set for Locator- 735 Set records sent in Map-Request and Map-Register messages. 737 R: This is set when the sender of a Map-Reply has a route to the 738 Locator in the Locator data record. This receiver may find this 739 useful to know if the Locator is up but not necessarily reachable 740 from the receiver's point of view. See also EID-Reachability 741 [I-D.ietf-lisp-rfc6830bis] for another way the R-bit may be used. 743 Locator: This is an IPv4 or IPv6 address (as encoded by the 'Loc- 744 AFI' field) assigned to an ETR. Note that the destination RLOC 745 address MAY be an anycast address. A source RLOC can be an 746 anycast address as well. The source or destination RLOC MUST NOT 747 be the broadcast address (255.255.255.255 or any subnet broadcast 748 address known to the router) and MUST NOT be a link-local 749 multicast address. The source RLOC MUST NOT be a multicast 750 address. The destination RLOC SHOULD be a multicast address if it 751 is being mapped from a multicast destination EID. 753 4.5. EID-to-RLOC UDP Map-Reply Message 755 A Map-Reply returns an EID-Prefix with a prefix length that is less 756 than or equal to the EID being requested. The EID being requested is 757 either from the destination field of an IP header of a Data-Probe or 758 the EID record of a Map-Request. The RLOCs in the Map-Reply are 759 globally routable IP addresses of all ETRs for the LISP site. Each 760 RLOC conveys status reachability but does not convey path 761 reachability from a requester's perspective. Separate testing of 762 path reachability is required. See RLOC-reachability 763 [I-D.ietf-lisp-rfc6830bis] for details. 765 Note that a Map-Reply may contain different EID-Prefix granularity 766 (prefix + length) than the Map-Request that triggers it. This might 767 occur if a Map-Request were for a prefix that had been returned by an 768 earlier Map-Reply. In such a case, the requester updates its cache 769 with the new prefix information and granularity. For example, a 770 requester with two cached EID-Prefixes that are covered by a Map- 771 Reply containing one less-specific prefix replaces the entry with the 772 less-specific EID-Prefix. Note that the reverse, replacement of one 773 less-specific prefix with multiple more-specific prefixes, can also 774 occur, not by removing the less-specific prefix but rather by adding 775 the more-specific prefixes that, during a lookup, will override the 776 less-specific prefix. 778 When an ETR is configured with overlapping EID-Prefixes, a Map- 779 Request with an EID that best matches any EID-Prefix MUST be returned 780 in a single Map-Reply message. For instance, if an ETR had database 781 mapping entries for EID-Prefixes: 783 10.0.0.0/8 784 10.1.0.0/16 785 10.1.1.0/24 786 10.1.2.0/24 788 A Map-Request for EID 10.1.1.1 would cause a Map-Reply with a record 789 count of 1 to be returned with a mapping record EID-Prefix of 790 10.1.1.0/24. 792 A Map-Request for EID 10.1.5.5 would cause a Map-Reply with a record 793 count of 3 to be returned with mapping records for EID-Prefixes 794 10.1.0.0/16, 10.1.1.0/24, and 10.1.2.0/24. 796 Note that not all overlapping EID-Prefixes need to be returned but 797 only the more-specific entries (note that in the second example above 798 10.0.0.0/8 was not returned for requesting EID 10.1.5.5) for the 799 matching EID-Prefix of the requesting EID. When more than one EID- 800 Prefix is returned, all SHOULD use the same Time to Live value so 801 they can all time out at the same time. When a more-specific EID- 802 Prefix is received later, its Time to Live value in the Map-Reply 803 record can be stored even when other less-specific entries exist. 804 When a less-specific EID-Prefix is received later, its map-cache 805 expiration time SHOULD be set to the minimum expiration time of any 806 more-specific EID-Prefix in the map-cache. This is done so the 807 integrity of the EID-Prefix set is wholly maintained and so no more- 808 specific entries are removed from the map-cache while keeping less- 809 specific entries. 811 Map-Replies SHOULD be sent for an EID-Prefix no more often than once 812 per second to the same requesting router. For scalability, it is 813 expected that aggregation of EID addresses into EID-Prefixes will 814 allow one Map-Reply to satisfy a mapping for the EID addresses in the 815 prefix range, thereby reducing the number of Map-Request messages. 817 Map-Reply records can have an empty Locator-Set. A Negative Map- 818 Reply is a Map-Reply with an empty Locator-Set. Negative Map-Replies 819 convey special actions by the sender to the ITR or PITR that have 820 solicited the Map-Reply. There are two primary applications for 821 Negative Map-Replies. The first is for a Map-Resolver to instruct an 822 ITR or PITR when a destination is for a LISP site versus a non-LISP 823 site, and the other is to source quench Map-Requests that are sent 824 for non-allocated EIDs. 826 For each Map-Reply record, the list of Locators in a Locator-Set MUST 827 appear in the same order for each ETR that originates a Map-Reply 828 message. The Locator-Set MUST be sorted in order of ascending IP 829 address where an IPv4 locator address is considered numerically 'less 830 than' an IPv6 locator address. 832 When sending a Map-Reply message, the destination address is copied 833 from one of the 'ITR-RLOC' fields from the Map-Request. The ETR can 834 choose a locator address from one of the address families it 835 supports. For Data-Probes, the destination address of the Map-Reply 836 is copied from the source address of the Data-Probe message that is 837 invoking the reply. The source address of the Map-Reply is one of 838 the local IP addresses chosen to allow Unicast Reverse Path 839 Forwarding (uRPF) checks to succeed in the upstream service provider. 840 The destination port of a Map-Reply message is copied from the source 841 port of the Map-Request or Data-Probe, and the source port of the 842 Map-Reply message is set to the well-known UDP port 4342. 844 4.6. Map-Register Message Format 846 This section specifies the encoding format for the Map-Register 847 message. The message is sent in UDP with a destination UDP port of 848 4342 and a randomly selected UDP source port number. 850 The Map-Register message format is: 852 0 1 2 3 853 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 1 854 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 855 |Type=3 |P|S|I| Reserved |E|T|a|m|M| Record Count | 856 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 857 | Nonce . . . | 858 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 859 | . . . Nonce | 860 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 861 | Key ID | Algorithm ID | Authentication Data Length | 862 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 863 ~ Authentication Data ~ 864 +-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 865 | | Record TTL | 866 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 867 R | Locator Count | EID mask-len | ACT |A| Reserved | 868 e +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 869 c | Rsvd | Map-Version Number | EID-Prefix-AFI | 870 o +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 871 r | EID-Prefix | 872 d +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 873 | /| Priority | Weight | M Priority | M Weight | 874 | L +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 875 | o | Unused Flags |L|p|R| Loc-AFI | 876 | c +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 877 | \| Locator | 878 +-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 880 Packet field descriptions: 882 Type: 3 (Map-Register) 884 P: This is the proxy Map-Reply bit. When set to 1, an ETR sends a 885 Map-Register message requesting the Map-Server to proxy a Map- 886 Reply. The Map-Server will send non-authoritative Map-Replies on 887 behalf of the ETR. 889 S: This is the security-capable bit. When set, the procedures from 890 [I-D.ietf-lisp-sec] are supported. 892 I: This is the xTR-ID bit. When this bit is set, what is appended to 893 the Map-Register is a 128-bit xTR router-ID and then a 64-bit 894 site-ID. See LISP NAT-Traversal procedures in 895 [I-D.ermagan-lisp-nat-traversal] for details. 897 Reserved: This field MUST be set to 0 on transmit and MUST be 898 ignored on receipt. 900 E: This is the Map-Register EID-notify bit. This is used by a First- 901 Hop-Router (FHR) which discovers a dynamic-EID. This EID-notify 902 based Map-Register is sent by the FHR to the same site xTR that 903 propogates the Map-Register to the mapping system. The site xTR 904 keeps state to later Map-Notify the FHR after the EID has moves 905 away. See [I-D.portoles-lisp-eid-mobility] for a detailed use- 906 case. 908 T: This is the use-TTL for timeout bit. When set to 1, the xTR wants 909 the Map-Server to time out registrations based on the value in the 910 "Record TTL" field of this message. 912 a: This is the merge-request bit. When set to 1, the xTR requests to 913 merge RLOC-records from different xTRs registering the same EID- 914 record. See signal-free multicast 915 [I-D.ietf-lisp-signal-free-multicast] for one use case example. 917 m: This is the mobile-node bit. When set to 1, the registering xTR 918 supports the procedures in [I-D.ietf-lisp-mn]. 920 M: This is the want-map-notify bit. When set to 1, an ETR is 921 requesting a Map-Notify message to be returned in response to 922 sending a Map-Register message. The Map-Notify message sent by a 923 Map-Server is used to acknowledge receipt of a Map-Register 924 message. 926 Record Count: This is the number of records in this Map-Register 927 message. A record is comprised of that portion of the packet 928 labeled 'Record' above and occurs the number of times equal to 929 Record Count. 931 Nonce: This 8-octet 'Nonce' field is set to 0 in Map-Register 932 messages. Since the Map-Register message is authenticated, the 933 'Nonce' field is not currently used for any security function but 934 may be in the future as part of an anti-replay solution. 936 Key ID: This is a configured key-id value that corresponds to a 937 shared-secret password that is used to authenticate the sender. 938 Multiple shared-secrets can be used to roll over keys in a non- 939 disruptive way. 941 Algorithm ID: This is the configured Message Authentication Code 942 (MAC) algorithm value used for the authentication function. See 943 Algorithm ID Numbers in the Section 7.3 for codepoint assignments. 945 Authentication Data Length: This is the length in octets of the 946 'Authentication Data' field that follows this field. The length 947 of the 'Authentication Data' field is dependent on the MAC 948 algorithm used. The length field allows a device that doesn't 949 know the MAC algorithm to correctly parse the packet. 951 Authentication Data: This is the message digest used from the output 952 of the MAC algorithm. The entire Map-Register payload is 953 authenticated with this field preset to 0. After the MAC is 954 computed, it is placed in this field. Implementations of this 955 specification MUST include support for HMAC-SHA-1-96 [RFC2404], 956 and support for HMAC-SHA-256-128 [RFC4868] is RECOMMENDED. 958 The definition of the rest of the Map-Register can be found in 959 Section 4.4. 961 4.7. Map-Notify/Map-Notify-Ack Message Format 963 This section specifies the encoding format for the Map-Notify and 964 Map-Notify-Ack messages. The messages are sent inside a UDP packet 965 with source and destination UDP ports equal to 4342. 967 The Map-Notify and Map-Notify-Ack message formats are: 969 0 1 2 3 970 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 1 971 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 972 |Type=4/5| Reserved | Record Count | 973 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 974 | Nonce . . . | 975 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 976 | . . . Nonce | 977 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 978 | Key ID | Algorithm ID | Authentication Data Length | 979 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 980 ~ Authentication Data ~ 981 +-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 982 | | Record TTL | 983 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 984 R | Locator Count | EID mask-len | ACT |A| Reserved | 985 e +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 986 c | Rsvd | Map-Version Number | EID-Prefix-AFI | 987 o +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 988 r | EID-Prefix | 989 d +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 990 | /| Priority | Weight | M Priority | M Weight | 991 | L +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 992 | o | Unused Flags |L|p|R| Loc-AFI | 993 | c +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 994 | \| Locator | 995 +-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 997 Packet field descriptions: 999 Type: 4/5 (Map-Notify/Map-Notify-Ack) 1001 The Map-Notify message has the same contents as a Map-Register 1002 message. See the Map-Register section for field descriptions. 1004 The Map-Notify-Ack message has the same contents as a Map-Notify 1005 message. It is used to acknowledge the receipt of a Map-Notify and 1006 for the sender to stop retransmitting a Map-Notify with the same 1007 nonce. 1009 4.8. Encapsulated Control Message Format 1011 An Encapsulated Control Message (ECM) is used to encapsulate control 1012 packets sent between xTRs and the mapping database system. 1014 0 1 2 3 1015 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 1016 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1017 / | IPv4 or IPv6 Header | 1018 OH | (uses RLOC addresses) | 1019 \ | | 1020 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1021 / | Source Port = xxxx | Dest Port = 4342 | 1022 UDP +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1023 \ | UDP Length | UDP Checksum | 1024 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1025 LH |Type=8 |S|D|E|M| Reserved | 1026 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1027 / | IPv4 or IPv6 Header | 1028 IH | (uses RLOC or EID addresses) | 1029 \ | | 1030 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1031 / | Source Port = xxxx | Dest Port = yyyy | 1032 UDP +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1033 \ | UDP Length | UDP Checksum | 1034 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1035 LCM | LISP Control Message | 1036 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1038 Packet header descriptions: 1040 OH: The outer IPv4 or IPv6 header, which uses RLOC addresses in the 1041 source and destination header address fields. 1043 UDP: The outer UDP header with destination port 4342. The source 1044 port is randomly allocated. The checksum field MUST be non- 1045 zero. 1047 LH: Type 8 is defined to be a "LISP Encapsulated Control Message", 1048 and what follows is either an IPv4 or IPv6 header as encoded by 1049 the first 4 bits after the 'Reserved' field. 1051 Type: 8 (Encapsulated Control Message (ECM)) 1053 S: This is the Security bit. When set to 1, the procedures from 1054 [I-D.ietf-lisp-sec] are followed. 1056 D: This is the DDT-bit. When set to 1, the sender is requesting a 1057 Map-Referral message to be returned. The details of this 1058 procedure are described in [I-D.ietf-lisp-ddt]. 1060 E: This is the to-ETR bit. When set to 1, the Map-Server's 1061 intention is to forward the ECM to an authoritative ETR. 1063 M: This is the to-MS bit. When set to 1, a Map-Request is being 1064 sent to a co-located Map-Resolver and Map-Server where the 1065 message can be processed directly by the Map-Server versus the 1066 Map-Resolver using the LISP-DDT procedures in 1067 [I-D.ietf-lisp-ddt]. 1069 0 1 2 3 1070 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 1071 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1072 | AD Type | Authentication Data Content . . . | 1073 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1075 IH: The inner IPv4 or IPv6 header, which can use either RLOC or EID 1076 addresses in the header address fields. When a Map-Request is 1077 encapsulated in this packet format, the destination address in 1078 this header is an EID. 1080 UDP: The inner UDP header, where the port assignments depend on the 1081 control packet being encapsulated. When the control packet is 1082 a Map-Request or Map-Register, the source port is selected by 1083 the ITR/PITR and the destination port is 4342. When the 1084 control packet is a Map-Reply, the source port is 4342 and the 1085 destination port is assigned from the source port of the 1086 invoking Map-Request. Port number 4341 MUST NOT be assigned to 1087 either port. The checksum field MUST be non-zero. 1089 LCM: The format is one of the control message formats described in 1090 this section. At this time, only Map-Request messages are 1091 allowed to be encapsulated. In the future, PIM Join/Prune 1092 messages [RFC6831] might be allowed. Encapsulating other types 1093 of LISP control messages is for further study. When Map- 1094 Requests are sent for RLOC-Probing purposes (i.e., the probe- 1095 bit is set), they MUST NOT be sent inside Encapsulated Control 1096 Messages. 1098 5. Interactions with Other LISP Components 1100 5.1. ITR EID-to-RLOC Mapping Resolution 1102 An ITR is configured with one or more Map-Resolver addresses. These 1103 addresses are "Locators" (or RLOCs) and must be routable on the 1104 underlying core network; they must not need to be resolved through 1105 LISP EID-to-RLOC mapping, as that would introduce a circular 1106 dependency. When using a Map-Resolver, an ITR does not need to 1107 connect to any other database mapping system. In particular, the ITR 1108 need not connect to the LISP+ALT infrastructure or implement the BGP 1109 and GRE protocols that it uses. 1111 An ITR sends an Encapsulated Map-Request to a configured Map-Resolver 1112 when it needs an EID-to-RLOC mapping that is not found in its local 1113 map-cache. Using the Map-Resolver greatly reduces both the 1114 complexity of the ITR implementation and the costs associated with 1115 its operation. 1117 In response to an Encapsulated Map-Request, the ITR can expect one of 1118 the following: 1120 o An immediate Negative Map-Reply (with action code of "Natively- 1121 Forward", 15-minute Time to Live (TTL)) from the Map-Resolver if 1122 the Map-Resolver can determine that the requested EID does not 1123 exist. The ITR saves the EID-Prefix returned in the Map-Reply in 1124 its cache, marks it as non-LISP-capable, and knows not to attempt 1125 LISP encapsulation for destinations matching it. 1127 o A Negative Map-Reply, with action code of "Natively-Forward", from 1128 a Map-Server that is authoritative for an EID-Prefix that matches 1129 the requested EID but that does not have an actively registered, 1130 more-specific ID-prefix. In this case, the requested EID is said 1131 to match a "hole" in the authoritative EID-Prefix. If the 1132 requested EID matches a more-specific EID-Prefix that has been 1133 delegated by the Map-Server but for which no ETRs are currently 1134 registered, a 1-minute TTL is returned. If the requested EID 1135 matches a non-delegated part of the authoritative EID-Prefix, then 1136 it is not a LISP EID and a 15-minute TTL is returned. See 1137 Section 5.2 for discussion of aggregate EID-Prefixes and details 1138 of Map-Server EID-Prefix matching. 1140 o A LISP Map-Reply from the ETR that owns the EID-to-RLOC mapping or 1141 possibly from a Map-Server answering on behalf of the ETR. See 1142 Section 5.4 for more details on Map-Resolver message processing. 1144 Note that an ITR may be configured to both use a Map-Resolver and to 1145 participate in a LISP+ALT logical network. In such a situation, the 1146 ITR should send Map-Requests through the ALT network for any EID- 1147 Prefix learned via ALT BGP. Such a configuration is expected to be 1148 very rare, since there is little benefit to using a Map-Resolver if 1149 an ITR is already using LISP+ALT. There would be, for example, no 1150 need for such an ITR to send a Map-Request to a possibly non-existent 1151 EID (and rely on Negative Map-Replies) if it can consult the ALT 1152 database to verify that an EID-Prefix is present before sending that 1153 Map-Request. 1155 5.2. EID-Prefix Configuration and ETR Registration 1157 An ETR publishes its EID-Prefixes on a Map-Server by sending LISP 1158 Map-Register messages. A Map-Register message includes 1159 authentication data, so prior to sending a Map-Register message, the 1160 ETR and Map-Server must be configured with a shared secret or other 1161 relevant authentication information. A Map-Server's configuration 1162 must also include a list of the EID-Prefixes for which each ETR is 1163 authoritative. Upon receipt of a Map-Register from an ETR, a Map- 1164 Server accepts only EID-Prefixes that are configured for that ETR. 1165 Failure to implement such a check would leave the mapping system 1166 vulnerable to trivial EID-Prefix hijacking attacks. As developers 1167 and operators gain experience with the mapping system, additional, 1168 stronger security measures may be added to the registration process. 1170 In addition to the set of EID-Prefixes defined for each ETR that may 1171 register, a Map-Server is typically also configured with one or more 1172 aggregate prefixes that define the part of the EID numbering space 1173 assigned to it. When LISP+ALT is the database in use, aggregate EID- 1174 Prefixes are implemented as discard routes and advertised into ALT 1175 BGP. The existence of aggregate EID-Prefixes in a Map-Server's 1176 database means that it may receive Map Requests for EID-Prefixes that 1177 match an aggregate but do not match a registered prefix; Section 5.3 1178 describes how this is handled. 1180 Map-Register messages are sent periodically from an ETR to a Map- 1181 Server with a suggested interval between messages of one minute. A 1182 Map-Server should time out and remove an ETR's registration if it has 1183 not received a valid Map-Register message within the past 1184 three minutes. When first contacting a Map-Server after restart or 1185 changes to its EID-to-RLOC database mappings, an ETR may initially 1186 send Map-Register messages at an increased frequency, up to one every 1187 20 seconds. This "quick registration" period is limited to 1188 five minutes in duration. 1190 An ETR may request that a Map-Server explicitly acknowledge receipt 1191 and processing of a Map-Register message by setting the "want-map- 1192 notify" (M-bit) flag. A Map-Server that receives a Map-Register with 1193 this flag set will respond with a Map-Notify message. Typical use of 1194 this flag by an ETR would be to set it for Map-Register messages sent 1195 during the initial "quick registration" with a Map-Server but then 1196 set it only occasionally during steady-state maintenance of its 1197 association with that Map-Server. Note that the Map-Notify message 1198 is sent to UDP destination port 4342, not to the source port 1199 specified in the original Map-Register message. 1201 Note that a one-minute minimum registration interval during 1202 maintenance of an ETR-Map-Server association places a lower bound on 1203 how quickly and how frequently a mapping database entry can be 1204 updated. This may have implications for what sorts of mobility can 1205 be supported directly by the mapping system; shorter registration 1206 intervals or other mechanisms might be needed to support faster 1207 mobility in some cases. For a discussion on one way that faster 1208 mobility may be implemented for individual devices, please see 1209 [I-D.ietf-lisp-mn]. 1211 An ETR may also request, by setting the "proxy Map-Reply" flag 1212 (P-bit) in the Map-Register message, that a Map-Server answer Map- 1213 Requests instead of forwarding them to the ETR. See 1214 [I-D.ietf-lisp-rfc6830bis] for details on how the Map-Server sets 1215 certain flags (such as those indicating whether the message is 1216 authoritative and how returned Locators should be treated) when 1217 sending a Map-Reply on behalf of an ETR. When an ETR requests proxy 1218 reply service, it should include all RLOCs for all ETRs for the EID- 1219 Prefix being registered, along with the routable flag ("R-bit") 1220 setting for each RLOC. The Map-Server includes all of this 1221 information in Map-Reply messages that it sends on behalf of the ETR. 1222 This differs from a non-proxy registration, since the latter need 1223 only provide one or more RLOCs for a Map-Server to use for forwarding 1224 Map-Requests; the registration information is not used in Map- 1225 Replies, so it being incomplete is not incorrect. 1227 An ETR that uses a Map-Server to publish its EID-to-RLOC mappings 1228 does not need to participate further in the mapping database 1229 protocol(s). When using a LISP+ALT mapping database, for example, 1230 this means that the ETR does not need to implement GRE or BGP, which 1231 greatly simplifies its configuration and reduces its cost of 1232 operation. 1234 Note that use of a Map-Server does not preclude an ETR from also 1235 connecting to the mapping database (i.e., it could also connect to 1236 the LISP+ALT network), but doing so doesn't seem particularly useful, 1237 as the whole purpose of using a Map-Server is to avoid the complexity 1238 of the mapping database protocols. 1240 5.3. Map-Server Processing 1242 Once a Map-Server has EID-Prefixes registered by its client ETRs, it 1243 can accept and process Map-Requests for them. 1245 In response to a Map-Request (received over the ALT if LISP+ALT is in 1246 use), the Map-Server first checks to see if the destination EID 1247 matches a configured EID-Prefix. If there is no match, the Map- 1248 Server returns a Negative Map-Reply with action code "Natively- 1249 Forward" and a 15-minute TTL. This may occur if a Map Request is 1250 received for a configured aggregate EID-Prefix for which no more- 1251 specific EID-Prefix exists; it indicates the presence of a non-LISP 1252 "hole" in the aggregate EID-Prefix. 1254 Next, the Map-Server checks to see if any ETRs have registered the 1255 matching EID-Prefix. If none are found, then the Map-Server returns 1256 a Negative Map-Reply with action code "Natively-Forward" and a 1257 1-minute TTL. 1259 If any of the registered ETRs for the EID-Prefix have requested proxy 1260 reply service, then the Map-Server answers the request instead of 1261 forwarding it. It returns a Map-Reply with the EID-Prefix, RLOCs, 1262 and other information learned through the registration process. 1264 If none of the ETRs have requested proxy reply service, then the Map- 1265 Server re-encapsulates and forwards the resulting Encapsulated Map- 1266 Request to one of the registered ETRs. It does not otherwise alter 1267 the Map-Request, so any Map-Reply sent by the ETR is returned to the 1268 RLOC in the Map-Request, not to the Map-Server. Unless also acting 1269 as a Map-Resolver, a Map-Server should never receive Map-Replies; any 1270 such messages should be discarded without response, perhaps 1271 accompanied by the logging of a diagnostic message if the rate of 1272 Map-Replies is suggestive of malicious traffic. 1274 5.4. Map-Resolver Processing 1276 Upon receipt of an Encapsulated Map-Request, a Map-Resolver 1277 decapsulates the enclosed message and then searches for the requested 1278 EID in its local database of mapping entries (statically configured 1279 or learned from associated ETRs if the Map-Resolver is also a Map- 1280 Server offering proxy reply service). If it finds a matching entry, 1281 it returns a LISP Map-Reply with the known mapping. 1283 If the Map-Resolver does not have the mapping entry and if it can 1284 determine that the EID is not in the mapping database (for example, 1285 if LISP+ALT is used, the Map-Resolver will have an ALT forwarding 1286 table that covers the full EID space), it immediately returns a 1287 negative LISP Map-Reply, with action code "Natively-Forward" and a 1288 15-minute TTL. To minimize the number of negative cache entries 1289 needed by an ITR, the Map-Resolver should return the least-specific 1290 prefix that both matches the original query and does not match any 1291 EID-Prefix known to exist in the LISP-capable infrastructure. 1293 If the Map-Resolver does not have sufficient information to know 1294 whether the EID exists, it needs to forward the Map-Request to 1295 another device that has more information about the EID being 1296 requested. To do this, it forwards the unencapsulated Map-Request, 1297 with the original ITR RLOC as the source, to the mapping database 1298 system. Using LISP+ALT, the Map-Resolver is connected to the ALT 1299 network and sends the Map-Request to the next ALT hop learned from 1300 its ALT BGP neighbors. The Map-Resolver does not send any response 1301 to the ITR; since the source RLOC is that of the ITR, the ETR or Map- 1302 Server that receives the Map-Request over the ALT and responds will 1303 do so directly to the ITR. 1305 5.4.1. Anycast Map-Resolver Operation 1307 A Map-Resolver can be set up to use "anycast", where the same address 1308 is assigned to multiple Map-Resolvers and is propagated through IGP 1309 routing, to facilitate the use of a topologically close Map-Resolver 1310 by each ITR. 1312 Note that Map-Server associations with ETRs should not use anycast 1313 addresses, as registrations need to be established between an ETR and 1314 a specific set of Map-Servers, each identified by a specific 1315 registration association. 1317 6. Security Considerations 1319 The 2-way LISP header nonce exchange documented in 1320 [I-D.ietf-lisp-rfc6830bis] can be used to avoid ITR spoofing attacks. 1322 To publish an authoritative EID-to-RLOC mapping with a Map-Server, an 1323 ETR includes authentication data that is a hash of the message using 1324 a pair-wise shared key. An implementation must support use of HMAC- 1325 SHA-1-96 [RFC2104] and should support use of HMAC-SHA-256-128 1326 [RFC6234] (SHA-256 truncated to 128 bits). 1328 As noted in Section 5.2, a Map-Server should verify that all EID- 1329 Prefixes registered by an ETR match the configuration stored on the 1330 Map-Server. 1332 The currently defined authentication mechanism for Map-Register 1333 messages does not provide protection against "replay" attacks by a 1334 "man-in-the-middle". Additional work is needed in this area. 1336 [I-D.ietf-lisp-sec] defines a proposed mechanism for providing origin 1337 authentication, integrity, anti-replay protection, and prevention of 1338 man-in-the-middle and "overclaiming" attacks on the Map-Request/Map- 1339 Reply exchange. Work is ongoing on this and other proposals for 1340 resolving these open security issues. 1342 While beyond the scope of securing an individual Map-Server or Map- 1343 Resolver, it should be noted that a BGP-based LISP+ALT network (if 1344 ALT is used as the mapping database infrastructure) can take 1345 advantage of standards work on adding security to BGP. 1347 A complete LISP threat analysis has been published in [RFC7835]. 1348 Please refer to it for more security related details. 1350 7. IANA Considerations 1352 This section provides guidance to the Internet Assigned Numbers 1353 Authority (IANA) regarding registration of values related to this 1354 LISP control-plane specification, in accordance with BCP 26 1355 [RFC5226]. 1357 There are three namespaces (listed in the sub-sections below) in LISP 1358 that have been registered. 1360 o LISP IANA registry allocations should not be made for purposes 1361 unrelated to LISP routing or transport protocols. 1363 o The following policies are used here with the meanings defined in 1364 BCP 26: "Specification Required", "IETF Review", "Experimental 1365 Use", and "First Come First Served". 1367 7.1. LISP Packet Type Codes 1369 It is being requested that the IANA be authoritative for LISP Packet 1370 Type definitions and that it refers to this document as well as 1371 [RFC8113] as references. 1373 Based on deployment experience of [RFC6830], the Map-Notify-Ack 1374 message, message type 5, was added to this document. This document 1375 requests IANA to add it to the LISP Packet Type Registry. 1377 7.2. LISP ACT and Flag Fields 1379 New ACT values an be allocated through IETF review or IESG approval. 1380 Four values have already been allocated by this specification. 1382 In addition, LISP has a number of flag fields and reserved fields, 1383 such as the LISP header flags field [I-D.ietf-lisp-rfc6830bis]. New 1384 bits for flags in these fields can be implemented after IETF review 1385 or IESG approval, but these need not be managed by IANA. 1387 7.3. LISP Address Type Codes 1389 LISP Canonical Address Format (LCAF) [RFC8060] is an 8-bit field that 1390 defines LISP-specific encodings for AFI value 16387. LCAF encodings 1391 are used for specific use-cases where different address types for 1392 EID-records and RLOC-records are required. 1394 The IANA registry "LISP Canonical Address Format (LCAF) Types" is 1395 used for LCAF types, the registry for LCAF types use the 1396 Specification Required policy [RFC5226]. Initial values for the 1397 registry as well as further information can be found in [RFC8060]. 1399 7.4. LISP Algorithm ID Numbers 1401 The following Algorithm ID values are defined by this specification 1402 as used in any packet type that references a 'Algorithm ID' field: 1404 Name Number Defined in 1405 ----------------------------------------------- 1406 None 0 n/a 1407 HMAC-SHA-1-96 1 [RFC2404] 1408 HMAC-SHA-256-128 2 [RFC4868] 1410 Number values are in the range of 0 to 255. The allocation of values 1411 is on a first come first served basis. 1413 8. References 1415 8.1. Normative References 1417 [RFC1035] Mockapetris, P., "Domain names - implementation and 1418 specification", STD 13, RFC 1035, DOI 10.17487/RFC1035, 1419 November 1987, . 1421 [RFC2104] Krawczyk, H., Bellare, M., and R. Canetti, "HMAC: Keyed- 1422 Hashing for Message Authentication", RFC 2104, 1423 DOI 10.17487/RFC2104, February 1997, 1424 . 1426 [RFC2404] Madson, C. and R. Glenn, "The Use of HMAC-SHA-1-96 within 1427 ESP and AH", RFC 2404, DOI 10.17487/RFC2404, November 1428 1998, . 1430 [RFC4086] Eastlake 3rd, D., Schiller, J., and S. Crocker, 1431 "Randomness Requirements for Security", BCP 106, RFC 4086, 1432 DOI 10.17487/RFC4086, June 2005, 1433 . 1435 [RFC4107] Bellovin, S. and R. Housley, "Guidelines for Cryptographic 1436 Key Management", BCP 107, RFC 4107, DOI 10.17487/RFC4107, 1437 June 2005, . 1439 [RFC4868] Kelly, S. and S. Frankel, "Using HMAC-SHA-256, HMAC-SHA- 1440 384, and HMAC-SHA-512 with IPsec", RFC 4868, 1441 DOI 10.17487/RFC4868, May 2007, 1442 . 1444 [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an 1445 IANA Considerations Section in RFCs", BCP 26, RFC 5226, 1446 DOI 10.17487/RFC5226, May 2008, 1447 . 1449 [RFC6234] Eastlake 3rd, D. and T. Hansen, "US Secure Hash Algorithms 1450 (SHA and SHA-based HMAC and HKDF)", RFC 6234, 1451 DOI 10.17487/RFC6234, May 2011, 1452 . 1454 [RFC6830] Farinacci, D., Fuller, V., Meyer, D., and D. Lewis, "The 1455 Locator/ID Separation Protocol (LISP)", RFC 6830, 1456 DOI 10.17487/RFC6830, January 2013, 1457 . 1459 [RFC6831] Farinacci, D., Meyer, D., Zwiebel, J., and S. Venaas, "The 1460 Locator/ID Separation Protocol (LISP) for Multicast 1461 Environments", RFC 6831, DOI 10.17487/RFC6831, January 1462 2013, . 1464 [RFC6836] Fuller, V., Farinacci, D., Meyer, D., and D. Lewis, 1465 "Locator/ID Separation Protocol Alternative Logical 1466 Topology (LISP+ALT)", RFC 6836, DOI 10.17487/RFC6836, 1467 January 2013, . 1469 [RFC6837] Lear, E., "NERD: A Not-so-novel Endpoint ID (EID) to 1470 Routing Locator (RLOC) Database", RFC 6837, 1471 DOI 10.17487/RFC6837, January 2013, 1472 . 1474 [RFC7348] Mahalingam, M., Dutt, D., Duda, K., Agarwal, P., Kreeger, 1475 L., Sridhar, T., Bursell, M., and C. Wright, "Virtual 1476 eXtensible Local Area Network (VXLAN): A Framework for 1477 Overlaying Virtualized Layer 2 Networks over Layer 3 1478 Networks", RFC 7348, DOI 10.17487/RFC7348, August 2014, 1479 . 1481 [RFC7835] Saucez, D., Iannone, L., and O. Bonaventure, "Locator/ID 1482 Separation Protocol (LISP) Threat Analysis", RFC 7835, 1483 DOI 10.17487/RFC7835, April 2016, 1484 . 1486 [RFC8060] Farinacci, D., Meyer, D., and J. Snijders, "LISP Canonical 1487 Address Format (LCAF)", RFC 8060, DOI 10.17487/RFC8060, 1488 February 2017, . 1490 [RFC8113] Boucadair, M. and C. Jacquenet, "Locator/ID Separation 1491 Protocol (LISP): Shared Extension Message & IANA Registry 1492 for Packet Type Allocations", RFC 8113, 1493 DOI 10.17487/RFC8113, March 2017, 1494 . 1496 8.2. Informative References 1498 [AFI] IANA, , "Address Family Identifier (AFIs)", ADDRESS FAMILY 1499 NUMBERS http://www.iana.org/assignments/address-family- 1500 numbers/address-family-numbers.xhtml?, Febuary 2007. 1502 [I-D.ermagan-lisp-nat-traversal] 1503 Ermagan, V., Farinacci, D., Lewis, D., Skriver, J., Maino, 1504 F., and C. White, "NAT traversal for LISP", draft-ermagan- 1505 lisp-nat-traversal-12 (work in progress), March 2017. 1507 [I-D.ietf-lisp-ddt] 1508 Fuller, V., Lewis, D., Ermagan, V., Jain, A., and A. 1509 Smirnov, "LISP Delegated Database Tree", draft-ietf-lisp- 1510 ddt-09 (work in progress), January 2017. 1512 [I-D.ietf-lisp-introduction] 1513 Cabellos-Aparicio, A. and D. Saucez, "An Architectural 1514 Introduction to the Locator/ID Separation Protocol 1515 (LISP)", draft-ietf-lisp-introduction-13 (work in 1516 progress), April 2015. 1518 [I-D.ietf-lisp-mn] 1519 Farinacci, D., Lewis, D., Meyer, D., and C. White, "LISP 1520 Mobile Node", draft-ietf-lisp-mn-00 (work in progress), 1521 April 2017. 1523 [I-D.ietf-lisp-rfc6830bis] 1524 Farinacci, D., Fuller, V., Meyer, D., Lewis, D., and A. 1525 Cabellos-Aparicio, "The Locator/ID Separation Protocol 1526 (LISP)", draft-ietf-lisp-rfc6830bis-02 (work in progress), 1527 April 2017. 1529 [I-D.ietf-lisp-sec] 1530 Maino, F., Ermagan, V., Cabellos-Aparicio, A., and D. 1531 Saucez, "LISP-Security (LISP-SEC)", draft-ietf-lisp-sec-12 1532 (work in progress), November 2016. 1534 [I-D.ietf-lisp-signal-free-multicast] 1535 Moreno, V. and D. Farinacci, "Signal-Free LISP Multicast", 1536 draft-ietf-lisp-signal-free-multicast-03 (work in 1537 progress), April 2017. 1539 [I-D.lewis-lisp-gpe] 1540 Lewis, D., Agarwal, P., Kreeger, L., Maino, F., Quinn, P., 1541 Smith, M., and N. Yadav, "LISP Generic Protocol 1542 Extension", draft-lewis-lisp-gpe-02 (work in progress), 1543 July 2014. 1545 [I-D.portoles-lisp-eid-mobility] 1546 Portoles-Comeras, M., Ashtaputre, V., Moreno, V., Maino, 1547 F., and D. Farinacci, "LISP L2/L3 EID Mobility Using a 1548 Unified Control Plane", draft-portoles-lisp-eid- 1549 mobility-02 (work in progress), April 2017. 1551 [I-D.quinn-vxlan-gpe] 1552 Quinn, P., Manur, R., Kreeger, L., Lewis, D., Maino, F., 1553 Smith, M., Agarwal, P., Yong, L., Xu, X., Elzur, U., Garg, 1554 P., and D. Melman, "Generic Protocol Extension for VXLAN", 1555 draft-quinn-vxlan-gpe-04 (work in progress), February 1556 2015. 1558 [LISP-CONS] 1559 Brim, S., Chiappa, N., Farinacci, D., Fuller, V., Lewis, 1560 D., and D. Meyer, "LISP-CONS: A Content distribution 1561 Overlay Network Service for LISP", Work in Progress, April 1562 2008. 1564 Appendix A. Acknowledgments 1566 The authors would like to thank Greg Schudel, Darrel Lewis, John 1567 Zwiebel, Andrew Partan, Dave Meyer, Isidor Kouvelas, Jesper Skriver, 1568 Fabio Maino, and members of the lisp@ietf.org mailing list for their 1569 feedback and helpful suggestions. 1571 Special thanks are due to Noel Chiappa for his extensive work on 1572 caching with LISP-CONS, some of which may be used by Map-Resolvers. 1574 Appendix B. Document Change Log 1576 [RFC Editor: Please delete this section on publication as RFC.] 1578 B.1. Changes to draft-ietf-lisp-rfc6833bis-04 1580 o Posted May 2017. 1582 o Clarify how the Key-ID field is used in Map-Register and Map- 1583 Notify messages. Break the 16-bit field into a 8-bit Key-ID field 1584 and a 8-bit Algorithm-ID field. 1586 o Move the control-plane codepoints from the IANA Considerations 1587 section of RFC6830bis to the IANA Considerations section of this 1588 document. 1590 o In the "LISP Control Packet Type Allocations" section, indicate 1591 how message Types are IANA allocated and how experimental RFC8113 1592 sub-types should be requested. 1594 B.2. Changes to draft-ietf-lisp-rfc6833bis-03 1596 o Posted April 2017. 1598 o Add types 9-14 and specify they are not assigned. 1600 o Add the "LISP Shared Extension Message" type and point to RFC8113. 1602 B.3. Changes to draft-ietf-lisp-rfc6833bis-02 1604 o Posted April 2017. 1606 o Clarify that the LISP control-plane document defines how the LISP 1607 data-plane uses Map-Requests with either the SMR-bit set or the 1608 P-bit set supporting mapping updates and RLOC-probing. Indicating 1609 that other data-planes can use the same mechanisms or their own 1610 defined mechanisms to achieve the same functionality. 1612 B.4. Changes to draft-ietf-lisp-rfc6833bis-01 1614 o Posted March 2017. 1616 o Include references to new RFCs published. 1618 o Remove references to self. 1620 o Change references from RFC6830 to RFC6830bis. 1622 o Add two new action/reasons to a Map-Reply has posted to the LISP 1623 WG mailing list. 1625 o In intro section, add refernece to I-D.ietf-lisp-introduction. 1627 o Removed Open Issues section and references to "experimental". 1629 B.5. Changes to draft-ietf-lisp-rfc6833bis-00 1631 o Posted December 2016. 1633 o Created working group document from draft-farinacci-lisp 1634 -rfc6833-00 individual submission. No other changes made. 1636 B.6. Changes to draft-farinacci-lisp-rfc6833bis-00 1638 o Posted November 2016. 1640 o This is the initial draft to turn RFC 6833 into RFC 6833bis. 1642 o The document name has changed from the "Locator/ID Separation 1643 Protocol (LISP) Map-Server Interface" to the "Locator/ID 1644 Separation Protocol (LISP) Control-Plane". 1646 o The fundamental change was to move the control-plane messages from 1647 RFC 6830 to this document in an effort so any IETF developed or 1648 industry created data-plane could use the LISP mapping system and 1649 control-plane. 1651 o Update control-plane messages to incorporate what has been 1652 implemented in products during the early phase of LISP development 1653 but wasn't able to make it into RFC6830 and RFC6833 to make the 1654 Experimental RFC deadline. 1656 o Indicate there may be nodes in the mapping system that are not MRs 1657 or MSs, that is a ALT-node or a DDT-node. 1659 o Include LISP-DDT in Map-Resolver section and explain how they 1660 maintain a referral-cache. 1662 o Removed open issue about additional state in Map-Servers. With 1663 [I-D.ietf-lisp-ddt], Map-Servers have the same registration state 1664 and can give Map-Resolvers complete information in ms-ack Map- 1665 Referral messages. 1667 o Make reference to the LISP Threats Analysis RFC [RFC7835]. 1669 Authors' Addresses 1671 Vince Fuller 1672 Cisco Systems 1674 EMail: vaf@vaf.net 1676 Dino Farinacci 1677 Cisco Systems 1679 EMail: farinacci@gmail.com 1681 Albert Cabellos 1682 UPC/BarcelonaTech 1683 Campus Nord, C. Jordi Girona 1-3 1684 Barcelona, Catalunya 1685 Spain 1687 EMail: acabello@ac.upc.edu