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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 10, 2017 A. Cabellos (Ed.) 6 UPC/BarcelonaTech 7 May 9, 2017 9 Locator/ID Separation Protocol (LISP) Control-Plane 10 draft-ietf-lisp-rfc6833bis-05 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 10, 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-05 . . . . . . . . 37 94 B.2. Changes to draft-ietf-lisp-rfc6833bis-04 . . . . . . . . 37 95 B.3. Changes to draft-ietf-lisp-rfc6833bis-03 . . . . . . . . 37 96 B.4. Changes to draft-ietf-lisp-rfc6833bis-02 . . . . . . . . 38 97 B.5. Changes to draft-ietf-lisp-rfc6833bis-01 . . . . . . . . 38 98 B.6. Changes to draft-ietf-lisp-rfc6833bis-00 . . . . . . . . 38 99 B.7. Changes to draft-farinacci-lisp-rfc6833bis-00 . . . . . . 38 100 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 39 102 1. Introduction 104 The Locator/ID Separation Protocol [I-D.ietf-lisp-introduction] and 105 [I-D.ietf-lisp-rfc6830bis] specifies an architecture and mechanism 106 for replacing the addresses currently used by IP with two separate 107 name spaces: Endpoint IDs (EIDs), used within sites; and Routing 108 Locators (RLOCs), used on the transit networks that make up the 109 Internet infrastructure. To achieve this separation, LISP defines 110 protocol mechanisms for mapping from EIDs to RLOCs. In addition, 111 LISP assumes the existence of a database to store and propagate those 112 mappings globally. Several such databases have been proposed; among 113 them are the Content distribution Overlay Network Service for LISP 114 (LISP-CONS) [LISP-CONS], LISP-NERD (a Not-so-novel EID-to-RLOC 115 Database) [RFC6837], LISP Alternative Logical Topology (LISP+ALT) 116 [RFC6836], and LISP Delegated Database Tree (LISP-DDT) 117 [I-D.ietf-lisp-ddt]. 119 The LISP Mapping Service defines two new types of LISP-speaking 120 devices: the Map-Resolver, which accepts Map-Requests from an Ingress 121 Tunnel Router (ITR) and "resolves" the EID-to-RLOC mapping using a 122 mapping database; and the Map-Server, which learns authoritative EID- 123 to-RLOC mappings from an Egress Tunnel Router (ETR) and publishes 124 them in a database. 126 This LISP Control-Plane Mapping Service can be used by many different 127 encapsulation-based or translation-based data-planes which include 128 but are not limited to the ones defined in LISP RFC 6830bis 129 [I-D.ietf-lisp-rfc6830bis], LISP-GPE [I-D.lewis-lisp-gpe], VXLAN 130 [RFC7348], and VXLAN-GPE [I-D.quinn-vxlan-gpe]. 132 Conceptually, LISP Map-Servers share some of the same basic 133 configuration and maintenance properties as Domain Name System (DNS) 134 [RFC1035] servers; likewise, Map-Resolvers are conceptually similar 135 to DNS caching resolvers. With this in mind, this specification 136 borrows familiar terminology (resolver and server) from the DNS 137 specifications. 139 Note that while this document assumes a LISP+ALT database mapping 140 infrastructure to illustrate certain aspects of Map-Server and Map- 141 Resolver operation, the Mapping Service interface can (and likely 142 will) be used by ITRs and ETRs to access other mapping database 143 systems as the LISP infrastructure evolves. 145 The LISP Mapping Service is an important component of the LISP 146 toolset. Issues and concerns about the deployment of LISP for 147 Internet traffic are discussed in [I-D.ietf-lisp-rfc6830bis]. 149 2. Definition of Terms 151 Map-Server: A network infrastructure component that learns of EID- 152 Prefix mapping entries from an ETR, via the registration mechanism 153 described below, or some other authoritative source if one exists. 154 A Map-Server publishes these EID-Prefixes in a mapping database. 156 Map-Resolver: A network infrastructure component that accepts LISP 157 Encapsulated Map-Requests, typically from an ITR, and determines 158 whether or not the destination IP address is part of the EID 159 namespace; if it is not, a Negative Map-Reply is returned. 160 Otherwise, the Map-Resolver finds the appropriate EID-to-RLOC 161 mapping by consulting a mapping database system. 163 Encapsulated Map-Request: A LISP Map-Request carried within an 164 Encapsulated Control Message, which has an additional LISP header 165 prepended. Sent to UDP destination port 4342. The "outer" 166 addresses are globally routable IP addresses, also known as RLOCs. 167 Used by an ITR when sending to a Map-Resolver and by a Map-Server 168 when forwarding a Map-Request to an ETR. 170 Negative Map-Reply: A LISP Map-Reply that contains an empty 171 Locator-Set. Returned in response to a Map-Request if the 172 destination EID does not exist in the mapping database. 173 Typically, this means that the "EID" being requested is an IP 174 address connected to a non-LISP site. 176 Map-Register message: A LISP message sent by an ETR to a Map-Server 177 to register its associated EID-Prefixes. In addition to the set 178 of EID-Prefixes to register, the message includes one or more 179 RLOCs to be used by the Map-Server when forwarding Map-Requests 180 (re-formatted as Encapsulated Map-Requests) received through the 181 database mapping system. An ETR may request that the Map-Server 182 answer Map-Requests on its behalf by setting the "proxy Map-Reply" 183 flag (P-bit) in the message. 185 Map-Notify message: A LISP message sent by a Map-Server to an ETR 186 to confirm that a Map-Register has been received and processed. 187 An ETR requests that a Map-Notify be returned by setting the 188 "want-map-notify" flag (M-bit) in the Map-Register message. 190 Unlike a Map-Reply, a Map-Notify uses UDP port 4342 for both 191 source and destination. 193 For definitions of other terms -- notably Map-Request, Map-Reply, 194 Ingress Tunnel Router (ITR), and Egress Tunnel Router (ETR) -- please 195 consult the LISP specification [I-D.ietf-lisp-rfc6830bis]. 197 3. Basic Overview 199 A Map-Server is a device that publishes EID-Prefixes in a LISP 200 mapping database on behalf of a set of ETRs. When it receives a Map 201 Request (typically from an ITR), it consults the mapping database to 202 find an ETR that can answer with the set of RLOCs for an EID-Prefix. 203 To publish its EID-Prefixes, an ETR periodically sends Map-Register 204 messages to the Map-Server. A Map-Register message contains a list 205 of EID-Prefixes plus a set of RLOCs that can be used to reach the ETR 206 when a Map-Server needs to forward a Map-Request to it. 208 When LISP+ALT is used as the mapping database, a Map-Server connects 209 to the ALT network and acts as a "last-hop" ALT-Router. Intermediate 210 ALT-Routers forward Map-Requests to the Map-Server that advertises a 211 particular EID-Prefix, and the Map-Server forwards them to the owning 212 ETR, which responds with Map-Reply messages. 214 When LISP-DDT [I-D.ietf-lisp-ddt] is used as the mapping database, a 215 Map-Server sends the final Map-Referral messages from the Delegated 216 Database Tree. 218 A Map-Resolver receives Encapsulated Map-Requests from its client 219 ITRs and uses a mapping database system to find the appropriate ETR 220 to answer those requests. On a LISP+ALT network, a Map-Resolver acts 221 as a "first-hop" ALT-Router. It has Generic Routing Encapsulation 222 (GRE) tunnels configured to other ALT-Routers and uses BGP to learn 223 paths to ETRs for different prefixes in the LISP+ALT database. The 224 Map-Resolver uses this path information to forward Map-Requests over 225 the ALT to the correct ETRs. On a LISP-DDT network 226 [I-D.ietf-lisp-ddt], a Map-Resolver maintains a referral-cache and 227 acts as a "first-hop" DDT-node. The Map-Resolver uses the referral 228 information to forward Map-Requests. 230 Note that while it is conceivable that a non-LISP-DDT Map-Resolver 231 could cache responses to improve performance, issues surrounding 232 cache management will need to be resolved so that doing so will be 233 reliable and practical. As initially deployed, Map-Resolvers will 234 operate only in a non-caching mode, decapsulating and forwarding 235 Encapsulated Map Requests received from ITRs. Any specification of 236 caching functionality is left for future work. 238 Note that a single device can implement the functions of both a Map- 239 Server and a Map-Resolver, and in many cases the functions will be 240 co-located in that way. Also, there can be ALT-only nodes and DDT- 241 only nodes, when LISP+ALT and LISP-DDT are used, respectively, to 242 connect Map-Resolvers and Map-Servers together to make up the Mapping 243 System. 245 Detailed descriptions of the LISP packet types referenced by this 246 document may be found in [I-D.ietf-lisp-rfc6830bis]. 248 4. LISP IPv4 and IPv6 Control-Plane Packet Formats 250 The following UDP packet formats are used by the LISP control plane. 252 0 1 2 3 253 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 1 254 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 255 |Version| IHL |Type of Service| Total Length | 256 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 257 | Identification |Flags| Fragment Offset | 258 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 259 | Time to Live | Protocol = 17 | Header Checksum | 260 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 261 | Source Routing Locator | 262 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 263 | Destination Routing Locator | 264 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 265 / | Source Port | Dest Port | 266 UDP +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 267 \ | UDP Length | UDP Checksum | 268 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 269 | | 270 | LISP Message | 271 | | 272 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 274 0 1 2 3 275 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 1 276 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 277 |Version| Traffic Class | Flow Label | 278 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 279 | Payload Length | Next Header=17| Hop Limit | 280 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 281 | | 282 + + 283 | | 284 + Source Routing Locator + 285 | | 286 + + 287 | | 288 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 289 | | 290 + + 291 | | 292 + Destination Routing Locator + 293 | | 294 + + 295 | | 296 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 297 / | Source Port | Dest Port | 298 UDP +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 299 \ | UDP Length | UDP Checksum | 300 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 301 | | 302 | LISP Message | 303 | | 304 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 306 The LISP UDP-based messages are the Map-Request and Map-Reply 307 messages. When a UDP Map-Request is sent, the UDP source port is 308 chosen by the sender and the destination UDP port number is set to 309 4342. When a UDP Map-Reply is sent, the source UDP port number is 310 set to 4342 and the destination UDP port number is copied from the 311 source port of either the Map-Request or the invoking data packet. 312 Implementations MUST be prepared to accept packets when either the 313 source port or destination UDP port is set to 4342 due to NATs 314 changing port number values. 316 The 'UDP Length' field will reflect the length of the UDP header and 317 the LISP Message payload. 319 The UDP checksum is computed and set to non-zero for Map-Request, 320 Map-Reply, Map-Register, and Encapsulated Control Message (ECM) 321 control messages. It MUST be checked on receipt, and if the checksum 322 fails, the packet MUST be dropped. 324 The format of control messages includes the UDP header so the 325 checksum and length fields can be used to protect and delimit message 326 boundaries. 328 4.1. LISP Control Packet Type Allocations 330 This section defines the LISP control message formats and summarizes 331 for IANA the LISP Type codes assigned by this document. For 332 completeness, this document references the LISP Shared Extension 333 Message assigned by [RFC8113]. Message type definitions are: 335 Reserved: 0 b'0000' 336 LISP Map-Request: 1 b'0001' 337 LISP Map-Reply: 2 b'0010' 338 LISP Map-Register: 3 b'0011' 339 LISP Map-Notify: 4 b'0100' 340 LISP Map-Notify-Ack: 5 b'0101' 341 LISP Map-Referral: 6 b'0110' 342 LISP Encapsulated Control Message: 8 b'1000' 343 Not Assigned 9-14 b'1001'- b'1110' 344 LISP Shared Extension Message: 15 b'1111' [RFC8113] 346 Values in the "Not Assigned" range can be assigned according to 347 procedures in [RFC5226]. Documents that request for a new LISP 348 packet type may indicate a preferred value in Section 7.3. 350 Protocol designers experimenting with new message formats should use 351 the LISP Shared Extension Message Type and request a [RFC8113] sub- 352 type assignment. 354 All LISP control-plane messages use Address Family Identifiers (AFI) 355 [AFI] or LISP Canonical Address Format (LCAF) [RFC8060] formats to 356 encode either fixed or variable length addresses. This includes 357 explicit fields in each control message or part of EID-records or 358 RLOC-records in commonly formatted messages. 360 The LISP control-plane describes how other data-planes can encode 361 messages to support the SMR and RLOC-probing procedures of the LISP 362 data-plane defined in [I-D.ietf-lisp-rfc6830bis]. This control-plane 363 specification itself does not offer such functionality and other 364 data-planes can use their own mechanisms that do not rely on the LISP 365 control-plane. 367 4.2. Map-Request Message Format 369 0 1 2 3 370 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 1 371 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 372 |Type=1 |A|M|P|S|p|s|m| Reserved |L|D| IRC | Record Count | 373 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 374 | Nonce . . . | 375 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 376 | . . . Nonce | 377 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 378 | Source-EID-AFI | Source EID Address ... | 379 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 380 | ITR-RLOC-AFI 1 | ITR-RLOC Address 1 ... | 381 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 382 | ... | 383 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 384 | ITR-RLOC-AFI n | ITR-RLOC Address n ... | 385 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 386 / | Reserved | EID mask-len | EID-Prefix-AFI | 387 Rec +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 388 \ | EID-Prefix ... | 389 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 390 | Map-Reply Record ... | 391 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 393 Packet field descriptions: 395 Type: 1 (Map-Request) 397 A: This is an authoritative bit, which is set to 0 for UDP-based Map- 398 Requests sent by an ITR. It is set to 1 when an ITR wants the 399 destination site to return the Map-Reply rather than the mapping 400 database system. 402 M: This is the map-data-present bit. When set, it indicates that a 403 Map-Reply Record segment is included in the Map-Request. 405 P: This is the probe-bit, which indicates that a Map-Request SHOULD 406 be treated as a Locator reachability probe. The receiver SHOULD 407 respond with a Map-Reply with the probe-bit set, indicating that 408 the Map-Reply is a Locator reachability probe reply, with the 409 nonce copied from the Map-Request. See RLOC-Probing 410 [I-D.ietf-lisp-rfc6830bis] for more details. 412 S: This is the Solicit-Map-Request (SMR) bit. See Solicit-Map- 413 Request (SMRs) [I-D.ietf-lisp-rfc6830bis] for details. 415 p: This is the PITR bit. This bit is set to 1 when a PITR sends a 416 Map-Request. 418 s: This is the SMR-invoked bit. This bit is set to 1 when an xTR is 419 sending a Map-Request in response to a received SMR-based Map- 420 Request. 422 m: This is the LISP mobile-node m-bit. This bit is set by xTRs that 423 operate as a mobile node as defined in [I-D.ietf-lisp-mn]. 425 Reserved: This field MUST be set to 0 on transmit and MUST be 426 ignored on receipt. 428 L: This is the local-xtr bit. It is used by an xTR in a LISP site to 429 tell other xTRs in the same site that it is local to the site. 430 That is, that it is part of the RLOC-set for the LISP site. 432 D: This is the dont-map-reply bit. It is used in the SMR procedure 433 described in [I-D.ietf-lisp-rfc6830bis]. When an xTR sends an SMR 434 Map-Request message, it doesn't need a Map-Reply returned. When 435 this bit is set, the receiver of the Map-Request does not return a 436 Map-Reply. 438 IRC: This 5-bit field is the ITR-RLOC Count, which encodes the 439 additional number of ('ITR-RLOC-AFI', 'ITR-RLOC Address') fields 440 present in this message. At least one (ITR-RLOC-AFI, ITR-RLOC- 441 Address) pair MUST be encoded. Multiple 'ITR-RLOC Address' fields 442 are used, so a Map-Replier can select which destination address to 443 use for a Map-Reply. The IRC value ranges from 0 to 31. For a 444 value of 0, there is 1 ITR-RLOC address encoded; for a value of 1, 445 there are 2 ITR-RLOC addresses encoded, and so on up to 31, which 446 encodes a total of 32 ITR-RLOC addresses. 448 Record Count: This is the number of records in this Map-Request 449 message. A record is comprised of the portion of the packet that 450 is labeled 'Rec' above and occurs the number of times equal to 451 Record Count. For this version of the protocol, a receiver MUST 452 accept and process Map-Requests that contain one or more records, 453 but a sender MUST only send Map-Requests containing one record. 454 Support for requesting multiple EIDs in a single Map-Request 455 message will be specified in a future version of the protocol. 457 Nonce: This is an 8-octet random value created by the sender of the 458 Map-Request. This nonce will be returned in the Map-Reply. The 459 security of the LISP mapping protocol critically depends on the 460 strength of the nonce in the Map-Request message. The nonce 461 SHOULD be generated by a properly seeded pseudo-random (or strong 462 random) source. See [RFC4086] for advice on generating security- 463 sensitive random data. 465 Source-EID-AFI: This is the address family of the 'Source EID 466 Address' field. 468 Source EID Address: This is the EID of the source host that 469 originated the packet that caused the Map-Request. When Map- 470 Requests are used for refreshing a Map-Cache entry or for RLOC- 471 Probing, an AFI value 0 is used and this field is of zero length. 473 ITR-RLOC-AFI: This is the address family of the 'ITR-RLOC Address' 474 field that follows this field. 476 ITR-RLOC Address: This is used to give the ETR the option of 477 selecting the destination address from any address family for the 478 Map-Reply message. This address MUST be a routable RLOC address 479 of the sender of the Map-Request message. 481 EID mask-len: This is the mask length for the EID-Prefix. 483 EID-Prefix-AFI: This is the address family of the EID-Prefix 484 according to [AFI] and [RFC8060]. 486 EID-Prefix: This prefix is 4 octets for an IPv4 address family and 487 16 octets for an IPv6 address family. When a Map-Request is sent 488 by an ITR because a data packet is received for a destination 489 where there is no mapping entry, the EID-Prefix is set to the 490 destination IP address of the data packet, and the 'EID mask-len' 491 is set to 32 or 128 for IPv4 or IPv6, respectively. When an xTR 492 wants to query a site about the status of a mapping it already has 493 cached, the EID-Prefix used in the Map-Request has the same mask 494 length as the EID-Prefix returned from the site when it sent a 495 Map-Reply message. 497 Map-Reply Record: When the M-bit is set, this field is the size of a 498 single "Record" in the Map-Reply format. This Map-Reply record 499 contains the EID-to-RLOC mapping entry associated with the Source 500 EID. This allows the ETR that will receive this Map-Request to 501 cache the data if it chooses to do so. 503 4.3. EID-to-RLOC UDP Map-Request Message 505 A Map-Request is sent from an ITR when it needs a mapping for an EID, 506 wants to test an RLOC for reachability, or wants to refresh a mapping 507 before TTL expiration. For the initial case, the destination IP 508 address used for the Map-Request is the data packet's destination 509 address (i.e., the destination EID) that had a mapping cache lookup 510 failure. For the latter two cases, the destination IP address used 511 for the Map-Request is one of the RLOC addresses from the Locator-Set 512 of the Map-Cache entry. The source address is either an IPv4 or IPv6 513 RLOC address, depending on whether the Map-Request is using an IPv4 514 or IPv6 header, respectively. In all cases, the UDP source port 515 number for the Map-Request message is a 16-bit value selected by the 516 ITR/PITR, and the UDP destination port number is set to the well- 517 known destination port number 4342. A successful Map-Reply, which is 518 one that has a nonce that matches an outstanding Map-Request nonce, 519 will update the cached set of RLOCs associated with the EID-Prefix 520 range. 522 One or more Map-Request ('ITR-RLOC-AFI', 'ITR-RLOC-Address') fields 523 MUST be filled in by the ITR. The number of fields (minus 1) encoded 524 MUST be placed in the 'IRC' field. The ITR MAY include all locally 525 configured Locators in this list or just provide one locator address 526 from each address family it supports. If the ITR erroneously 527 provides no ITR-RLOC addresses, the Map-Replier MUST drop the Map- 528 Request. 530 Map-Requests can also be LISP encapsulated using UDP destination 531 port 4342 with a LISP Type value set to "Encapsulated Control 532 Message", when sent from an ITR to a Map-Resolver. Likewise, Map- 533 Requests are LISP encapsulated the same way from a Map-Server to an 534 ETR. Details on Encapsulated Map-Requests and Map-Resolvers can be 535 found in Section 4.8. 537 Map-Requests MUST be rate-limited. It is RECOMMENDED that a Map- 538 Request for the same EID-Prefix be sent no more than once per second. 540 An ITR that is configured with mapping database information (i.e., it 541 is also an ETR) MAY optionally include those mappings in a Map- 542 Request. When an ETR configured to accept and verify such 543 "piggybacked" mapping data receives such a Map-Request and it does 544 not have this mapping in the map-cache, it MAY originate a "verifying 545 Map-Request", addressed to the map-requesting ITR and the ETR MAY add 546 a Map-Cache entry. If the ETR has a Map-Cache entry that matches the 547 "piggybacked" EID and the RLOC is in the Locator-Set for the entry, 548 then it may send the "verifying Map-Request" directly to the 549 originating Map-Request source. If the RLOC is not in the Locator- 550 Set, then the ETR MUST send the "verifying Map-Request" to the 551 "piggybacked" EID. Doing this forces the "verifying Map-Request" to 552 go through the mapping database system to reach the authoritative 553 source of information about that EID, guarding against RLOC-spoofing 554 in the "piggybacked" mapping data. 556 4.4. Map-Reply Message Format 558 0 1 2 3 559 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 1 560 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 561 |Type=2 |P|E|S| Reserved | Record Count | 562 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 563 | Nonce . . . | 564 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 565 | . . . Nonce | 566 +-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 567 | | Record TTL | 568 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 569 R | Locator Count | EID mask-len | ACT |A| Reserved | 570 e +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 571 c | Rsvd | Map-Version Number | EID-Prefix-AFI | 572 o +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 573 r | EID-Prefix | 574 d +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 575 | /| Priority | Weight | M Priority | M Weight | 576 | L +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 577 | o | Unused Flags |L|p|R| Loc-AFI | 578 | c +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 579 | \| Locator | 580 +-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 582 Packet field descriptions: 584 Type: 2 (Map-Reply) 586 P: This is the probe-bit, which indicates that the Map-Reply is in 587 response to a Locator reachability probe Map-Request. The 'Nonce' 588 field MUST contain a copy of the nonce value from the original 589 Map-Request. See RLOC-probing [I-D.ietf-lisp-rfc6830bis] for more 590 details. 592 E: This bit indicates that the ETR that sends this Map-Reply message 593 is advertising that the site is enabled for the Echo-Nonce Locator 594 reachability algorithm. See Echo-Nonce [I-D.ietf-lisp-rfc6830bis] 595 for more details. 597 S: This is the Security bit. When set to 1, the following 598 authentication information will be appended to the end of the Map- 599 Reply. The details of signing a Map-Reply message can be found in 600 [I-D.ietf-lisp-sec]. 602 0 1 2 3 603 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 1 604 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 605 | AD Type | Authentication Data Content . . . | 606 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 608 Reserved: This field MUST be set to 0 on transmit and MUST be 609 ignored on receipt. 611 Record Count: This is the number of records in this reply message. 612 A record is comprised of that portion of the packet labeled 613 'Record' above and occurs the number of times equal to Record 614 Count. 616 Nonce: This is a 24-bit value set in a Data-Probe packet, or a 617 64-bit value from the Map-Request is echoed in this 'Nonce' field 618 of the Map-Reply. When a 24-bit value is supplied, it resides in 619 the low-order 64 bits of the 'Nonce' field. 621 Record TTL: This is the time in minutes the recipient of the Map- 622 Reply will store the mapping. If the TTL is 0, the entry SHOULD 623 be removed from the cache immediately. If the value is 624 0xffffffff, the recipient can decide locally how long to store the 625 mapping. 627 Locator Count: This is the number of Locator entries. A Locator 628 entry comprises what is labeled above as 'Loc'. The Locator count 629 can be 0, indicating that there are no Locators for the EID- 630 Prefix. 632 EID mask-len: This is the mask length for the EID-Prefix. 634 ACT: This 3-bit field describes Negative Map-Reply actions. In any 635 other message type, these bits are set to 0 and ignored on 636 receipt. These bits are used only when the 'Locator Count' field 637 is set to 0. The action bits are encoded only in Map-Reply 638 messages. The actions defined are used by an ITR or PITR when a 639 destination EID matches a negative Map-Cache entry. Unassigned 640 values should cause a Map-Cache entry to be created, and when 641 packets match this negative cache entry, they will be dropped. 642 The current assigned values are: 644 (0) No-Action: The map-cache is kept alive, and no packet 645 encapsulation occurs. 647 (1) Natively-Forward: The packet is not encapsulated or dropped 648 but natively forwarded. 650 (2) Send-Map-Request: The packet invokes sending a Map-Request. 652 (3) Drop/No-Reason: A packet that matches this map-cache entry is 653 dropped. An ICMP Destination Unreachable message SHOULD be 654 sent. 656 (4) Drop/Policy-Denied: A packet that matches this map-cache 657 entry is dropped. The reason for the Drop action is that a 658 Map-Request for the target-EID is being policy denied by 659 either an xTR or the mapping system. 661 (5) Drop/Authentication-Failure: A packet that matches this map- 662 cache entry is dropped. The reason for the Drop action is 663 that a Map-Request for the target-EID fails an authentication 664 verification-check by either an xTR or the mapping system. 666 A: The Authoritative bit, when sent, is always set to 1 by an ETR. 667 When a Map-Server is proxy Map-Replying for a LISP site, the 668 Authoritative bit is set to 0. This indicates to requesting ITRs 669 that the Map-Reply was not originated by a LISP node managed at 670 the site that owns the EID-Prefix. 672 Map-Version Number: When this 12-bit value is non-zero, the Map- 673 Reply sender is informing the ITR what the version number is for 674 the EID record contained in the Map-Reply. The ETR can allocate 675 this number internally but MUST coordinate this value with other 676 ETRs for the site. When this value is 0, there is no versioning 677 information conveyed. The Map-Version Number can be included in 678 Map-Request and Map-Register messages. See Map-Versioning 679 [I-D.ietf-lisp-rfc6830bis] for more details. 681 EID-Prefix-AFI: Address family of the EID-Prefix according to [AFI] 682 and [RFC8060]. 684 EID-Prefix: This prefix is 4 octets for an IPv4 address family and 685 16 octets for an IPv6 address family. 687 Priority: Each RLOC is assigned a unicast Priority. Lower values 688 are more preferable. When multiple RLOCs have the same Priority, 689 they MAY be used in a load-split fashion. A value of 255 means 690 the RLOC MUST NOT be used for unicast forwarding. 692 Weight: When priorities are the same for multiple RLOCs, the Weight 693 indicates how to balance unicast traffic between them. Weight is 694 encoded as a relative weight of total unicast packets that match 695 the mapping entry. For example, if there are 4 Locators in a 696 Locator-Set, where the Weights assigned are 30, 20, 20, and 10, 697 the first Locator will get 37.5% of the traffic, the 2nd and 3rd 698 Locators will get 25% of the traffic, and the 4th Locator will get 699 12.5% of the traffic. If all Weights for a Locator-Set are equal, 700 the receiver of the Map-Reply will decide how to load-split the 701 traffic. See RLOC-hashing [I-D.ietf-lisp-rfc6830bis] for a 702 suggested hash algorithm to distribute the load across Locators 703 with the same Priority and equal Weight values. 705 M Priority: Each RLOC is assigned a multicast Priority used by an 706 ETR in a receiver multicast site to select an ITR in a source 707 multicast site for building multicast distribution trees. A value 708 of 255 means the RLOC MUST NOT be used for joining a multicast 709 distribution tree. For more details, see [RFC6831]. 711 M Weight: When priorities are the same for multiple RLOCs, the 712 Weight indicates how to balance building multicast distribution 713 trees across multiple ITRs. The Weight is encoded as a relative 714 weight (similar to the unicast Weights) of the total number of 715 trees built to the source site identified by the EID-Prefix. If 716 all Weights for a Locator-Set are equal, the receiver of the Map- 717 Reply will decide how to distribute multicast state across ITRs. 718 For more details, see [RFC6831]. 720 Unused Flags: These are set to 0 when sending and ignored on 721 receipt. 723 L: When this bit is set, the Locator is flagged as a local Locator to 724 the ETR that is sending the Map-Reply. When a Map-Server is doing 725 proxy Map-Replying for a LISP site, the L-bit is set to 0 for all 726 Locators in this Locator-Set. 728 p: When this bit is set, an ETR informs the RLOC-Probing ITR that the 729 locator address for which this bit is set is the one being RLOC- 730 probed and MAY be different from the source address of the Map- 731 Reply. An ITR that RLOC-probes a particular Locator MUST use this 732 Locator for retrieving the data structure used to store the fact 733 that the Locator is reachable. The p-bit is set for a single 734 Locator in the same Locator-Set. If an implementation sets more 735 than one p-bit erroneously, the receiver of the Map-Reply MUST 736 select the first Locator. The p-bit MUST NOT be set for Locator- 737 Set records sent in Map-Request and Map-Register messages. 739 R: This is set when the sender of a Map-Reply has a route to the 740 Locator in the Locator data record. This receiver may find this 741 useful to know if the Locator is up but not necessarily reachable 742 from the receiver's point of view. See also EID-Reachability 743 [I-D.ietf-lisp-rfc6830bis] for another way the R-bit may be used. 745 Locator: This is an IPv4 or IPv6 address (as encoded by the 'Loc- 746 AFI' field) assigned to an ETR. Note that the destination RLOC 747 address MAY be an anycast address. A source RLOC can be an 748 anycast address as well. The source or destination RLOC MUST NOT 749 be the broadcast address (255.255.255.255 or any subnet broadcast 750 address known to the router) and MUST NOT be a link-local 751 multicast address. The source RLOC MUST NOT be a multicast 752 address. The destination RLOC SHOULD be a multicast address if it 753 is being mapped from a multicast destination EID. 755 4.5. EID-to-RLOC UDP Map-Reply Message 757 A Map-Reply returns an EID-Prefix with a prefix length that is less 758 than or equal to the EID being requested. The EID being requested is 759 either from the destination field of an IP header of a Data-Probe or 760 the EID record of a Map-Request. The RLOCs in the Map-Reply are 761 globally routable IP addresses of all ETRs for the LISP site. Each 762 RLOC conveys status reachability but does not convey path 763 reachability from a requester's perspective. Separate testing of 764 path reachability is required. See RLOC-reachability 765 [I-D.ietf-lisp-rfc6830bis] for details. 767 Note that a Map-Reply may contain different EID-Prefix granularity 768 (prefix + length) than the Map-Request that triggers it. This might 769 occur if a Map-Request were for a prefix that had been returned by an 770 earlier Map-Reply. In such a case, the requester updates its cache 771 with the new prefix information and granularity. For example, a 772 requester with two cached EID-Prefixes that are covered by a Map- 773 Reply containing one less-specific prefix replaces the entry with the 774 less-specific EID-Prefix. Note that the reverse, replacement of one 775 less-specific prefix with multiple more-specific prefixes, can also 776 occur, not by removing the less-specific prefix but rather by adding 777 the more-specific prefixes that, during a lookup, will override the 778 less-specific prefix. 780 When an ETR is configured with overlapping EID-Prefixes, a Map- 781 Request with an EID that best matches any EID-Prefix MUST be returned 782 in a single Map-Reply message. For instance, if an ETR had database 783 mapping entries for EID-Prefixes: 785 10.0.0.0/8 786 10.1.0.0/16 787 10.1.1.0/24 788 10.1.2.0/24 790 A Map-Request for EID 10.1.1.1 would cause a Map-Reply with a record 791 count of 1 to be returned with a mapping record EID-Prefix of 792 10.1.1.0/24. 794 A Map-Request for EID 10.1.5.5 would cause a Map-Reply with a record 795 count of 3 to be returned with mapping records for EID-Prefixes 796 10.1.0.0/16, 10.1.1.0/24, and 10.1.2.0/24. 798 Note that not all overlapping EID-Prefixes need to be returned but 799 only the more-specific entries (note that in the second example above 800 10.0.0.0/8 was not returned for requesting EID 10.1.5.5) for the 801 matching EID-Prefix of the requesting EID. When more than one EID- 802 Prefix is returned, all SHOULD use the same Time to Live value so 803 they can all time out at the same time. When a more-specific EID- 804 Prefix is received later, its Time to Live value in the Map-Reply 805 record can be stored even when other less-specific entries exist. 806 When a less-specific EID-Prefix is received later, its map-cache 807 expiration time SHOULD be set to the minimum expiration time of any 808 more-specific EID-Prefix in the map-cache. This is done so the 809 integrity of the EID-Prefix set is wholly maintained and so no more- 810 specific entries are removed from the map-cache while keeping less- 811 specific entries. 813 Map-Replies SHOULD be sent for an EID-Prefix no more often than once 814 per second to the same requesting router. For scalability, it is 815 expected that aggregation of EID addresses into EID-Prefixes will 816 allow one Map-Reply to satisfy a mapping for the EID addresses in the 817 prefix range, thereby reducing the number of Map-Request messages. 819 Map-Reply records can have an empty Locator-Set. A Negative Map- 820 Reply is a Map-Reply with an empty Locator-Set. Negative Map-Replies 821 convey special actions by the sender to the ITR or PITR that have 822 solicited the Map-Reply. There are two primary applications for 823 Negative Map-Replies. The first is for a Map-Resolver to instruct an 824 ITR or PITR when a destination is for a LISP site versus a non-LISP 825 site, and the other is to source quench Map-Requests that are sent 826 for non-allocated EIDs. 828 For each Map-Reply record, the list of Locators in a Locator-Set MUST 829 appear in the same order for each ETR that originates a Map-Reply 830 message. The Locator-Set MUST be sorted in order of ascending IP 831 address where an IPv4 locator address is considered numerically 'less 832 than' an IPv6 locator address. 834 When sending a Map-Reply message, the destination address is copied 835 from one of the 'ITR-RLOC' fields from the Map-Request. The ETR can 836 choose a locator address from one of the address families it 837 supports. For Data-Probes, the destination address of the Map-Reply 838 is copied from the source address of the Data-Probe message that is 839 invoking the reply. The source address of the Map-Reply is one of 840 the local IP addresses chosen to allow Unicast Reverse Path 841 Forwarding (uRPF) checks to succeed in the upstream service provider. 842 The destination port of a Map-Reply message is copied from the source 843 port of the Map-Request or Data-Probe, and the source port of the 844 Map-Reply message is set to the well-known UDP port 4342. 846 4.6. Map-Register Message Format 848 This section specifies the encoding format for the Map-Register 849 message. The message is sent in UDP with a destination UDP port of 850 4342 and a randomly selected UDP source port number. 852 The Map-Register message format is: 854 0 1 2 3 855 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 1 856 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 857 |Type=3 |P|S|I| Reserved |E|T|a|m|M| Record Count | 858 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 859 | Nonce . . . | 860 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 861 | . . . Nonce | 862 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 863 | Key ID | Algorithm ID | Authentication Data Length | 864 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 865 ~ Authentication Data ~ 866 +-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 867 | | Record TTL | 868 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 869 R | Locator Count | EID mask-len | ACT |A| Reserved | 870 e +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 871 c | Rsvd | Map-Version Number | EID-Prefix-AFI | 872 o +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 873 r | EID-Prefix | 874 d +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 875 | /| Priority | Weight | M Priority | M Weight | 876 | L +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 877 | o | Unused Flags |L|p|R| Loc-AFI | 878 | c +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 879 | \| Locator | 880 +-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 882 Packet field descriptions: 884 Type: 3 (Map-Register) 886 P: This is the proxy Map-Reply bit. When set to 1, an ETR sends a 887 Map-Register message requesting the Map-Server to proxy a Map- 888 Reply. The Map-Server will send non-authoritative Map-Replies on 889 behalf of the ETR. 891 S: This is the security-capable bit. When set, the procedures from 892 [I-D.ietf-lisp-sec] are supported. 894 I: This is the xTR-ID bit. When this bit is set, what is appended to 895 the Map-Register is a 128-bit xTR router-ID and then a 64-bit 896 site-ID. See LISP NAT-Traversal procedures in 897 [I-D.ermagan-lisp-nat-traversal] for details. 899 Reserved: This field MUST be set to 0 on transmit and MUST be 900 ignored on receipt. 902 E: This is the Map-Register EID-notify bit. This is used by a First- 903 Hop-Router (FHR) which discovers a dynamic-EID. This EID-notify 904 based Map-Register is sent by the FHR to the same site xTR that 905 propogates the Map-Register to the mapping system. The site xTR 906 keeps state to later Map-Notify the FHR after the EID has moves 907 away. See [I-D.portoles-lisp-eid-mobility] for a detailed use- 908 case. 910 T: This is the use-TTL for timeout bit. When set to 1, the xTR wants 911 the Map-Server to time out registrations based on the value in the 912 "Record TTL" field of this message. 914 a: This is the merge-request bit. When set to 1, the xTR requests to 915 merge RLOC-records from different xTRs registering the same EID- 916 record. See signal-free multicast 917 [I-D.ietf-lisp-signal-free-multicast] for one use case example. 919 m: This is the mobile-node bit. When set to 1, the registering xTR 920 supports the procedures in [I-D.ietf-lisp-mn]. 922 M: This is the want-map-notify bit. When set to 1, an ETR is 923 requesting a Map-Notify message to be returned in response to 924 sending a Map-Register message. The Map-Notify message sent by a 925 Map-Server is used to acknowledge receipt of a Map-Register 926 message. 928 Record Count: This is the number of records in this Map-Register 929 message. A record is comprised of that portion of the packet 930 labeled 'Record' above and occurs the number of times equal to 931 Record Count. 933 Nonce: This 8-octet 'Nonce' field is set to 0 in Map-Register 934 messages. Since the Map-Register message is authenticated, the 935 'Nonce' field is not currently used for any security function but 936 may be in the future as part of an anti-replay solution. 938 Key ID: This is a configured key-id value that corresponds to a 939 shared-secret password that is used to authenticate the sender. 940 Multiple shared-secrets can be used to roll over keys in a non- 941 disruptive way. 943 Algorithm ID: This is the configured Message Authentication Code 944 (MAC) algorithm value used for the authentication function. See 945 Algorithm ID Numbers in the Section 7.3 for codepoint assignments. 947 Authentication Data Length: This is the length in octets of the 948 'Authentication Data' field that follows this field. The length 949 of the 'Authentication Data' field is dependent on the MAC 950 algorithm used. The length field allows a device that doesn't 951 know the MAC algorithm to correctly parse the packet. 953 Authentication Data: This is the message digest used from the output 954 of the MAC algorithm. The entire Map-Register payload is 955 authenticated with this field preset to 0. After the MAC is 956 computed, it is placed in this field. Implementations of this 957 specification MUST include support for HMAC-SHA-1-96 [RFC2404], 958 and support for HMAC-SHA-256-128 [RFC4868] is RECOMMENDED. 960 The definition of the rest of the Map-Register can be found in 961 Section 4.4. 963 4.7. Map-Notify/Map-Notify-Ack Message Format 965 This section specifies the encoding format for the Map-Notify and 966 Map-Notify-Ack messages. The messages are sent inside a UDP packet 967 with source and destination UDP ports equal to 4342. 969 The Map-Notify and Map-Notify-Ack message formats are: 971 0 1 2 3 972 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 1 973 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 974 |Type=4/5| Reserved | Record Count | 975 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 976 | Nonce . . . | 977 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 978 | . . . Nonce | 979 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 980 | Key ID | Algorithm ID | Authentication Data Length | 981 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 982 ~ Authentication Data ~ 983 +-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 984 | | Record TTL | 985 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 986 R | Locator Count | EID mask-len | ACT |A| Reserved | 987 e +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 988 c | Rsvd | Map-Version Number | EID-Prefix-AFI | 989 o +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 990 r | EID-Prefix | 991 d +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 992 | /| Priority | Weight | M Priority | M Weight | 993 | L +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 994 | o | Unused Flags |L|p|R| Loc-AFI | 995 | c +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 996 | \| Locator | 997 +-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 999 Packet field descriptions: 1001 Type: 4/5 (Map-Notify/Map-Notify-Ack) 1003 The Map-Notify message has the same contents as a Map-Register 1004 message. See the Map-Register section for field descriptions. 1006 The Map-Notify-Ack message has the same contents as a Map-Notify 1007 message. It is used to acknowledge the receipt of a Map-Notify and 1008 for the sender to stop retransmitting a Map-Notify with the same 1009 nonce. 1011 4.8. Encapsulated Control Message Format 1013 An Encapsulated Control Message (ECM) is used to encapsulate control 1014 packets sent between xTRs and the mapping database system. 1016 0 1 2 3 1017 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 1018 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1019 / | IPv4 or IPv6 Header | 1020 OH | (uses RLOC addresses) | 1021 \ | | 1022 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1023 / | Source Port = xxxx | Dest Port = 4342 | 1024 UDP +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1025 \ | UDP Length | UDP Checksum | 1026 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1027 LH |Type=8 |S|D|E|M| Reserved | 1028 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1029 / | IPv4 or IPv6 Header | 1030 IH | (uses RLOC or EID addresses) | 1031 \ | | 1032 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1033 / | Source Port = xxxx | Dest Port = yyyy | 1034 UDP +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1035 \ | UDP Length | UDP Checksum | 1036 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1037 LCM | LISP Control Message | 1038 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1040 Packet header descriptions: 1042 OH: The outer IPv4 or IPv6 header, which uses RLOC addresses in the 1043 source and destination header address fields. 1045 UDP: The outer UDP header with destination port 4342. The source 1046 port is randomly allocated. The checksum field MUST be non- 1047 zero. 1049 LH: Type 8 is defined to be a "LISP Encapsulated Control Message", 1050 and what follows is either an IPv4 or IPv6 header as encoded by 1051 the first 4 bits after the 'Reserved' field. 1053 Type: 8 (Encapsulated Control Message (ECM)) 1055 S: This is the Security bit. When set to 1, the procedures from 1056 [I-D.ietf-lisp-sec] are followed. 1058 D: This is the DDT-bit. When set to 1, the sender is requesting a 1059 Map-Referral message to be returned. The details of this 1060 procedure are described in [I-D.ietf-lisp-ddt]. 1062 E: This is the to-ETR bit. When set to 1, the Map-Server's 1063 intention is to forward the ECM to an authoritative ETR. 1065 M: This is the to-MS bit. When set to 1, a Map-Request is being 1066 sent to a co-located Map-Resolver and Map-Server where the 1067 message can be processed directly by the Map-Server versus the 1068 Map-Resolver using the LISP-DDT procedures in 1069 [I-D.ietf-lisp-ddt]. 1071 0 1 2 3 1072 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 1073 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1074 | AD Type | Authentication Data Content . . . | 1075 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1077 IH: The inner IPv4 or IPv6 header, which can use either RLOC or EID 1078 addresses in the header address fields. When a Map-Request is 1079 encapsulated in this packet format, the destination address in 1080 this header is an EID. 1082 UDP: The inner UDP header, where the port assignments depend on the 1083 control packet being encapsulated. When the control packet is 1084 a Map-Request or Map-Register, the source port is selected by 1085 the ITR/PITR and the destination port is 4342. When the 1086 control packet is a Map-Reply, the source port is 4342 and the 1087 destination port is assigned from the source port of the 1088 invoking Map-Request. Port number 4341 MUST NOT be assigned to 1089 either port. The checksum field MUST be non-zero. 1091 LCM: The format is one of the control message formats described in 1092 this section. At this time, only Map-Request messages are 1093 allowed to be encapsulated. In the future, PIM Join/Prune 1094 messages [RFC6831] might be allowed. Encapsulating other types 1095 of LISP control messages is for further study. When Map- 1096 Requests are sent for RLOC-Probing purposes (i.e., the probe- 1097 bit is set), they MUST NOT be sent inside Encapsulated Control 1098 Messages. 1100 5. Interactions with Other LISP Components 1102 5.1. ITR EID-to-RLOC Mapping Resolution 1104 An ITR is configured with one or more Map-Resolver addresses. These 1105 addresses are "Locators" (or RLOCs) and must be routable on the 1106 underlying core network; they must not need to be resolved through 1107 LISP EID-to-RLOC mapping, as that would introduce a circular 1108 dependency. When using a Map-Resolver, an ITR does not need to 1109 connect to any other database mapping system. In particular, the ITR 1110 need not connect to the LISP+ALT infrastructure or implement the BGP 1111 and GRE protocols that it uses. 1113 An ITR sends an Encapsulated Map-Request to a configured Map-Resolver 1114 when it needs an EID-to-RLOC mapping that is not found in its local 1115 map-cache. Using the Map-Resolver greatly reduces both the 1116 complexity of the ITR implementation and the costs associated with 1117 its operation. 1119 In response to an Encapsulated Map-Request, the ITR can expect one of 1120 the following: 1122 o An immediate Negative Map-Reply (with action code of "Natively- 1123 Forward", 15-minute Time to Live (TTL)) from the Map-Resolver if 1124 the Map-Resolver can determine that the requested EID does not 1125 exist. The ITR saves the EID-Prefix returned in the Map-Reply in 1126 its cache, marks it as non-LISP-capable, and knows not to attempt 1127 LISP encapsulation for destinations matching it. 1129 o A Negative Map-Reply, with action code of "Natively-Forward", from 1130 a Map-Server that is authoritative for an EID-Prefix that matches 1131 the requested EID but that does not have an actively registered, 1132 more-specific ID-prefix. In this case, the requested EID is said 1133 to match a "hole" in the authoritative EID-Prefix. If the 1134 requested EID matches a more-specific EID-Prefix that has been 1135 delegated by the Map-Server but for which no ETRs are currently 1136 registered, a 1-minute TTL is returned. If the requested EID 1137 matches a non-delegated part of the authoritative EID-Prefix, then 1138 it is not a LISP EID and a 15-minute TTL is returned. See 1139 Section 5.2 for discussion of aggregate EID-Prefixes and details 1140 of Map-Server EID-Prefix matching. 1142 o A LISP Map-Reply from the ETR that owns the EID-to-RLOC mapping or 1143 possibly from a Map-Server answering on behalf of the ETR. See 1144 Section 5.4 for more details on Map-Resolver message processing. 1146 Note that an ITR may be configured to both use a Map-Resolver and to 1147 participate in a LISP+ALT logical network. In such a situation, the 1148 ITR should send Map-Requests through the ALT network for any EID- 1149 Prefix learned via ALT BGP. Such a configuration is expected to be 1150 very rare, since there is little benefit to using a Map-Resolver if 1151 an ITR is already using LISP+ALT. There would be, for example, no 1152 need for such an ITR to send a Map-Request to a possibly non-existent 1153 EID (and rely on Negative Map-Replies) if it can consult the ALT 1154 database to verify that an EID-Prefix is present before sending that 1155 Map-Request. 1157 5.2. EID-Prefix Configuration and ETR Registration 1159 An ETR publishes its EID-Prefixes on a Map-Server by sending LISP 1160 Map-Register messages. A Map-Register message includes 1161 authentication data, so prior to sending a Map-Register message, the 1162 ETR and Map-Server must be configured with a shared secret or other 1163 relevant authentication information. A Map-Server's configuration 1164 must also include a list of the EID-Prefixes for which each ETR is 1165 authoritative. Upon receipt of a Map-Register from an ETR, a Map- 1166 Server accepts only EID-Prefixes that are configured for that ETR. 1167 Failure to implement such a check would leave the mapping system 1168 vulnerable to trivial EID-Prefix hijacking attacks. As developers 1169 and operators gain experience with the mapping system, additional, 1170 stronger security measures may be added to the registration process. 1172 In addition to the set of EID-Prefixes defined for each ETR that may 1173 register, a Map-Server is typically also configured with one or more 1174 aggregate prefixes that define the part of the EID numbering space 1175 assigned to it. When LISP+ALT is the database in use, aggregate EID- 1176 Prefixes are implemented as discard routes and advertised into ALT 1177 BGP. The existence of aggregate EID-Prefixes in a Map-Server's 1178 database means that it may receive Map Requests for EID-Prefixes that 1179 match an aggregate but do not match a registered prefix; Section 5.3 1180 describes how this is handled. 1182 Map-Register messages are sent periodically from an ETR to a Map- 1183 Server with a suggested interval between messages of one minute. A 1184 Map-Server should time out and remove an ETR's registration if it has 1185 not received a valid Map-Register message within the past 1186 three minutes. When first contacting a Map-Server after restart or 1187 changes to its EID-to-RLOC database mappings, an ETR may initially 1188 send Map-Register messages at an increased frequency, up to one every 1189 20 seconds. This "quick registration" period is limited to 1190 five minutes in duration. 1192 An ETR may request that a Map-Server explicitly acknowledge receipt 1193 and processing of a Map-Register message by setting the "want-map- 1194 notify" (M-bit) flag. A Map-Server that receives a Map-Register with 1195 this flag set will respond with a Map-Notify message. Typical use of 1196 this flag by an ETR would be to set it for Map-Register messages sent 1197 during the initial "quick registration" with a Map-Server but then 1198 set it only occasionally during steady-state maintenance of its 1199 association with that Map-Server. Note that the Map-Notify message 1200 is sent to UDP destination port 4342, not to the source port 1201 specified in the original Map-Register message. 1203 Note that a one-minute minimum registration interval during 1204 maintenance of an ETR-Map-Server association places a lower bound on 1205 how quickly and how frequently a mapping database entry can be 1206 updated. This may have implications for what sorts of mobility can 1207 be supported directly by the mapping system; shorter registration 1208 intervals or other mechanisms might be needed to support faster 1209 mobility in some cases. For a discussion on one way that faster 1210 mobility may be implemented for individual devices, please see 1211 [I-D.ietf-lisp-mn]. 1213 An ETR may also request, by setting the "proxy Map-Reply" flag 1214 (P-bit) in the Map-Register message, that a Map-Server answer Map- 1215 Requests instead of forwarding them to the ETR. See 1216 [I-D.ietf-lisp-rfc6830bis] for details on how the Map-Server sets 1217 certain flags (such as those indicating whether the message is 1218 authoritative and how returned Locators should be treated) when 1219 sending a Map-Reply on behalf of an ETR. When an ETR requests proxy 1220 reply service, it should include all RLOCs for all ETRs for the EID- 1221 Prefix being registered, along with the routable flag ("R-bit") 1222 setting for each RLOC. The Map-Server includes all of this 1223 information in Map-Reply messages that it sends on behalf of the ETR. 1224 This differs from a non-proxy registration, since the latter need 1225 only provide one or more RLOCs for a Map-Server to use for forwarding 1226 Map-Requests; the registration information is not used in Map- 1227 Replies, so it being incomplete is not incorrect. 1229 An ETR that uses a Map-Server to publish its EID-to-RLOC mappings 1230 does not need to participate further in the mapping database 1231 protocol(s). When using a LISP+ALT mapping database, for example, 1232 this means that the ETR does not need to implement GRE or BGP, which 1233 greatly simplifies its configuration and reduces its cost of 1234 operation. 1236 Note that use of a Map-Server does not preclude an ETR from also 1237 connecting to the mapping database (i.e., it could also connect to 1238 the LISP+ALT network), but doing so doesn't seem particularly useful, 1239 as the whole purpose of using a Map-Server is to avoid the complexity 1240 of the mapping database protocols. 1242 5.3. Map-Server Processing 1244 Once a Map-Server has EID-Prefixes registered by its client ETRs, it 1245 can accept and process Map-Requests for them. 1247 In response to a Map-Request (received over the ALT if LISP+ALT is in 1248 use), the Map-Server first checks to see if the destination EID 1249 matches a configured EID-Prefix. If there is no match, the Map- 1250 Server returns a Negative Map-Reply with action code "Natively- 1251 Forward" and a 15-minute TTL. This may occur if a Map Request is 1252 received for a configured aggregate EID-Prefix for which no more- 1253 specific EID-Prefix exists; it indicates the presence of a non-LISP 1254 "hole" in the aggregate EID-Prefix. 1256 Next, the Map-Server checks to see if any ETRs have registered the 1257 matching EID-Prefix. If none are found, then the Map-Server returns 1258 a Negative Map-Reply with action code "Natively-Forward" and a 1259 1-minute TTL. 1261 If any of the registered ETRs for the EID-Prefix have requested proxy 1262 reply service, then the Map-Server answers the request instead of 1263 forwarding it. It returns a Map-Reply with the EID-Prefix, RLOCs, 1264 and other information learned through the registration process. 1266 If none of the ETRs have requested proxy reply service, then the Map- 1267 Server re-encapsulates and forwards the resulting Encapsulated Map- 1268 Request to one of the registered ETRs. It does not otherwise alter 1269 the Map-Request, so any Map-Reply sent by the ETR is returned to the 1270 RLOC in the Map-Request, not to the Map-Server. Unless also acting 1271 as a Map-Resolver, a Map-Server should never receive Map-Replies; any 1272 such messages should be discarded without response, perhaps 1273 accompanied by the logging of a diagnostic message if the rate of 1274 Map-Replies is suggestive of malicious traffic. 1276 5.4. Map-Resolver Processing 1278 Upon receipt of an Encapsulated Map-Request, a Map-Resolver 1279 decapsulates the enclosed message and then searches for the requested 1280 EID in its local database of mapping entries (statically configured 1281 or learned from associated ETRs if the Map-Resolver is also a Map- 1282 Server offering proxy reply service). If it finds a matching entry, 1283 it returns a LISP Map-Reply with the known mapping. 1285 If the Map-Resolver does not have the mapping entry and if it can 1286 determine that the EID is not in the mapping database (for example, 1287 if LISP+ALT is used, the Map-Resolver will have an ALT forwarding 1288 table that covers the full EID space), it immediately returns a 1289 negative LISP Map-Reply, with action code "Natively-Forward" and a 1290 15-minute TTL. To minimize the number of negative cache entries 1291 needed by an ITR, the Map-Resolver should return the least-specific 1292 prefix that both matches the original query and does not match any 1293 EID-Prefix known to exist in the LISP-capable infrastructure. 1295 If the Map-Resolver does not have sufficient information to know 1296 whether the EID exists, it needs to forward the Map-Request to 1297 another device that has more information about the EID being 1298 requested. To do this, it forwards the unencapsulated Map-Request, 1299 with the original ITR RLOC as the source, to the mapping database 1300 system. Using LISP+ALT, the Map-Resolver is connected to the ALT 1301 network and sends the Map-Request to the next ALT hop learned from 1302 its ALT BGP neighbors. The Map-Resolver does not send any response 1303 to the ITR; since the source RLOC is that of the ITR, the ETR or Map- 1304 Server that receives the Map-Request over the ALT and responds will 1305 do so directly to the ITR. 1307 5.4.1. Anycast Map-Resolver Operation 1309 A Map-Resolver can be set up to use "anycast", where the same address 1310 is assigned to multiple Map-Resolvers and is propagated through IGP 1311 routing, to facilitate the use of a topologically close Map-Resolver 1312 by each ITR. 1314 Note that Map-Server associations with ETRs should not use anycast 1315 addresses, as registrations need to be established between an ETR and 1316 a specific set of Map-Servers, each identified by a specific 1317 registration association. 1319 6. Security Considerations 1321 The 2-way LISP header nonce exchange documented in 1322 [I-D.ietf-lisp-rfc6830bis] can be used to avoid ITR spoofing attacks. 1324 To publish an authoritative EID-to-RLOC mapping with a Map-Server, an 1325 ETR includes authentication data that is a hash of the message using 1326 a pair-wise shared key. An implementation must support use of HMAC- 1327 SHA-1-96 [RFC2104] and should support use of HMAC-SHA-256-128 1328 [RFC6234] (SHA-256 truncated to 128 bits). 1330 As noted in Section 5.2, a Map-Server should verify that all EID- 1331 Prefixes registered by an ETR match the configuration stored on the 1332 Map-Server. 1334 The currently defined authentication mechanism for Map-Register 1335 messages does not provide protection against "replay" attacks by a 1336 "man-in-the-middle". Additional work is needed in this area. 1338 [I-D.ietf-lisp-sec] defines a proposed mechanism for providing origin 1339 authentication, integrity, anti-replay protection, and prevention of 1340 man-in-the-middle and "overclaiming" attacks on the Map-Request/Map- 1341 Reply exchange. Work is ongoing on this and other proposals for 1342 resolving these open security issues. 1344 While beyond the scope of securing an individual Map-Server or Map- 1345 Resolver, it should be noted that a BGP-based LISP+ALT network (if 1346 ALT is used as the mapping database infrastructure) can take 1347 advantage of standards work on adding security to BGP. 1349 A complete LISP threat analysis has been published in [RFC7835]. 1350 Please refer to it for more security related details. 1352 7. IANA Considerations 1354 This section provides guidance to the Internet Assigned Numbers 1355 Authority (IANA) regarding registration of values related to this 1356 LISP control-plane specification, in accordance with BCP 26 1357 [RFC5226]. 1359 There are three namespaces (listed in the sub-sections below) in LISP 1360 that have been registered. 1362 o LISP IANA registry allocations should not be made for purposes 1363 unrelated to LISP routing or transport protocols. 1365 o The following policies are used here with the meanings defined in 1366 BCP 26: "Specification Required", "IETF Review", "Experimental 1367 Use", and "First Come First Served". 1369 7.1. LISP Packet Type Codes 1371 It is being requested that the IANA be authoritative for LISP Packet 1372 Type definitions and that it refers to this document as well as 1373 [RFC8113] as references. 1375 Based on deployment experience of [RFC6830], the Map-Notify-Ack 1376 message, message type 5, was added to this document. This document 1377 requests IANA to add it to the LISP Packet Type Registry. 1379 7.2. LISP ACT and Flag Fields 1381 New ACT values can be allocated through IETF review or IESG approval. 1382 Four values have already been allocated by [RFC6830]. This 1383 specification changes the name of ACT type 3 value from "Drop" to 1384 "Drop/No-Reason" as well as adding two new ACT values, the "Drop/ 1385 Policy-Denied" (type 4) and "Drop/Authentication-Failure" (type 5). 1387 In addition, LISP has a number of flag fields and reserved fields, 1388 such as the LISP header flags field [I-D.ietf-lisp-rfc6830bis]. New 1389 bits for flags in these fields can be implemented after IETF review 1390 or IESG approval, but these need not be managed by IANA. 1392 7.3. LISP Address Type Codes 1394 LISP Canonical Address Format (LCAF) [RFC8060] is an 8-bit field that 1395 defines LISP-specific encodings for AFI value 16387. LCAF encodings 1396 are used for specific use-cases where different address types for 1397 EID-records and RLOC-records are required. 1399 The IANA registry "LISP Canonical Address Format (LCAF) Types" is 1400 used for LCAF types, the registry for LCAF types use the 1401 Specification Required policy [RFC5226]. Initial values for the 1402 registry as well as further information can be found in [RFC8060]. 1404 Therefore, there is no longer a need for the "LISP Address Type 1405 Codes" registry requested by [RFC6830]. This document requests to 1406 remove it. 1408 7.4. LISP Algorithm ID Numbers 1410 In [RFC6830], a request for a "LISP Key ID Numbers" registry was 1411 submitted. This document renames the registry to "LISP Algorithm ID 1412 Numbers" and requests the IANA to make the name change. 1414 The following Algorithm ID values are defined by this specification 1415 as used in any packet type that references a 'Algorithm ID' field: 1417 Name Number Defined in 1418 ----------------------------------------------- 1419 None 0 n/a 1420 HMAC-SHA-1-96 1 [RFC2404] 1421 HMAC-SHA-256-128 2 [RFC4868] 1423 Number values are in the range of 0 to 255. The allocation of values 1424 is on a first come first served basis. 1426 8. References 1428 8.1. Normative References 1430 [RFC1035] Mockapetris, P., "Domain names - implementation and 1431 specification", STD 13, RFC 1035, DOI 10.17487/RFC1035, 1432 November 1987, . 1434 [RFC2104] Krawczyk, H., Bellare, M., and R. Canetti, "HMAC: Keyed- 1435 Hashing for Message Authentication", RFC 2104, 1436 DOI 10.17487/RFC2104, February 1997, 1437 . 1439 [RFC2404] Madson, C. and R. Glenn, "The Use of HMAC-SHA-1-96 within 1440 ESP and AH", RFC 2404, DOI 10.17487/RFC2404, November 1441 1998, . 1443 [RFC4086] Eastlake 3rd, D., Schiller, J., and S. Crocker, 1444 "Randomness Requirements for Security", BCP 106, RFC 4086, 1445 DOI 10.17487/RFC4086, June 2005, 1446 . 1448 [RFC4107] Bellovin, S. and R. Housley, "Guidelines for Cryptographic 1449 Key Management", BCP 107, RFC 4107, DOI 10.17487/RFC4107, 1450 June 2005, . 1452 [RFC4868] Kelly, S. and S. Frankel, "Using HMAC-SHA-256, HMAC-SHA- 1453 384, and HMAC-SHA-512 with IPsec", RFC 4868, 1454 DOI 10.17487/RFC4868, May 2007, 1455 . 1457 [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an 1458 IANA Considerations Section in RFCs", BCP 26, RFC 5226, 1459 DOI 10.17487/RFC5226, May 2008, 1460 . 1462 [RFC6234] Eastlake 3rd, D. and T. Hansen, "US Secure Hash Algorithms 1463 (SHA and SHA-based HMAC and HKDF)", RFC 6234, 1464 DOI 10.17487/RFC6234, May 2011, 1465 . 1467 [RFC6830] Farinacci, D., Fuller, V., Meyer, D., and D. Lewis, "The 1468 Locator/ID Separation Protocol (LISP)", RFC 6830, 1469 DOI 10.17487/RFC6830, January 2013, 1470 . 1472 [RFC6831] Farinacci, D., Meyer, D., Zwiebel, J., and S. Venaas, "The 1473 Locator/ID Separation Protocol (LISP) for Multicast 1474 Environments", RFC 6831, DOI 10.17487/RFC6831, January 1475 2013, . 1477 [RFC6836] Fuller, V., Farinacci, D., Meyer, D., and D. Lewis, 1478 "Locator/ID Separation Protocol Alternative Logical 1479 Topology (LISP+ALT)", RFC 6836, DOI 10.17487/RFC6836, 1480 January 2013, . 1482 [RFC6837] Lear, E., "NERD: A Not-so-novel Endpoint ID (EID) to 1483 Routing Locator (RLOC) Database", RFC 6837, 1484 DOI 10.17487/RFC6837, January 2013, 1485 . 1487 [RFC7348] Mahalingam, M., Dutt, D., Duda, K., Agarwal, P., Kreeger, 1488 L., Sridhar, T., Bursell, M., and C. Wright, "Virtual 1489 eXtensible Local Area Network (VXLAN): A Framework for 1490 Overlaying Virtualized Layer 2 Networks over Layer 3 1491 Networks", RFC 7348, DOI 10.17487/RFC7348, August 2014, 1492 . 1494 [RFC7835] Saucez, D., Iannone, L., and O. Bonaventure, "Locator/ID 1495 Separation Protocol (LISP) Threat Analysis", RFC 7835, 1496 DOI 10.17487/RFC7835, April 2016, 1497 . 1499 [RFC8060] Farinacci, D., Meyer, D., and J. Snijders, "LISP Canonical 1500 Address Format (LCAF)", RFC 8060, DOI 10.17487/RFC8060, 1501 February 2017, . 1503 [RFC8113] Boucadair, M. and C. Jacquenet, "Locator/ID Separation 1504 Protocol (LISP): Shared Extension Message & IANA Registry 1505 for Packet Type Allocations", RFC 8113, 1506 DOI 10.17487/RFC8113, March 2017, 1507 . 1509 8.2. Informative References 1511 [AFI] IANA, , "Address Family Identifier (AFIs)", ADDRESS FAMILY 1512 NUMBERS http://www.iana.org/assignments/address-family- 1513 numbers/address-family-numbers.xhtml?, Febuary 2007. 1515 [I-D.ermagan-lisp-nat-traversal] 1516 Ermagan, V., Farinacci, D., Lewis, D., Skriver, J., Maino, 1517 F., and C. White, "NAT traversal for LISP", draft-ermagan- 1518 lisp-nat-traversal-12 (work in progress), March 2017. 1520 [I-D.ietf-lisp-ddt] 1521 Fuller, V., Lewis, D., Ermagan, V., Jain, A., and A. 1522 Smirnov, "LISP Delegated Database Tree", draft-ietf-lisp- 1523 ddt-09 (work in progress), January 2017. 1525 [I-D.ietf-lisp-introduction] 1526 Cabellos-Aparicio, A. and D. Saucez, "An Architectural 1527 Introduction to the Locator/ID Separation Protocol 1528 (LISP)", draft-ietf-lisp-introduction-13 (work in 1529 progress), April 2015. 1531 [I-D.ietf-lisp-mn] 1532 Farinacci, D., Lewis, D., Meyer, D., and C. White, "LISP 1533 Mobile Node", draft-ietf-lisp-mn-00 (work in progress), 1534 April 2017. 1536 [I-D.ietf-lisp-rfc6830bis] 1537 Farinacci, D., Fuller, V., Meyer, D., Lewis, D., and A. 1538 Cabellos-Aparicio, "The Locator/ID Separation Protocol 1539 (LISP)", draft-ietf-lisp-rfc6830bis-03 (work in progress), 1540 May 2017. 1542 [I-D.ietf-lisp-sec] 1543 Maino, F., Ermagan, V., Cabellos-Aparicio, A., and D. 1544 Saucez, "LISP-Security (LISP-SEC)", draft-ietf-lisp-sec-12 1545 (work in progress), November 2016. 1547 [I-D.ietf-lisp-signal-free-multicast] 1548 Moreno, V. and D. Farinacci, "Signal-Free LISP Multicast", 1549 draft-ietf-lisp-signal-free-multicast-04 (work in 1550 progress), May 2017. 1552 [I-D.lewis-lisp-gpe] 1553 Lewis, D., Agarwal, P., Kreeger, L., Maino, F., Quinn, P., 1554 Smith, M., and N. Yadav, "LISP Generic Protocol 1555 Extension", draft-lewis-lisp-gpe-02 (work in progress), 1556 July 2014. 1558 [I-D.portoles-lisp-eid-mobility] 1559 Portoles-Comeras, M., Ashtaputre, V., Moreno, V., Maino, 1560 F., and D. Farinacci, "LISP L2/L3 EID Mobility Using a 1561 Unified Control Plane", draft-portoles-lisp-eid- 1562 mobility-02 (work in progress), April 2017. 1564 [I-D.quinn-vxlan-gpe] 1565 Quinn, P., Manur, R., Kreeger, L., Lewis, D., Maino, F., 1566 Smith, M., Agarwal, P., Yong, L., Xu, X., Elzur, U., Garg, 1567 P., and D. Melman, "Generic Protocol Extension for VXLAN", 1568 draft-quinn-vxlan-gpe-04 (work in progress), February 1569 2015. 1571 [LISP-CONS] 1572 Brim, S., Chiappa, N., Farinacci, D., Fuller, V., Lewis, 1573 D., and D. Meyer, "LISP-CONS: A Content distribution 1574 Overlay Network Service for LISP", Work in Progress, April 1575 2008. 1577 Appendix A. Acknowledgments 1579 The authors would like to thank Greg Schudel, Darrel Lewis, John 1580 Zwiebel, Andrew Partan, Dave Meyer, Isidor Kouvelas, Jesper Skriver, 1581 Fabio Maino, and members of the lisp@ietf.org mailing list for their 1582 feedback and helpful suggestions. 1584 Special thanks are due to Noel Chiappa for his extensive work on 1585 caching with LISP-CONS, some of which may be used by Map-Resolvers. 1587 Appendix B. Document Change Log 1589 [RFC Editor: Please delete this section on publication as RFC.] 1591 B.1. Changes to draft-ietf-lisp-rfc6833bis-05 1593 o Posted May 2017. 1595 o Update IANA Considerations section based on new requests from this 1596 document and changes from what was requested in [RFC6830]. 1598 B.2. Changes to draft-ietf-lisp-rfc6833bis-04 1600 o Posted May 2017. 1602 o Clarify how the Key-ID field is used in Map-Register and Map- 1603 Notify messages. Break the 16-bit field into a 8-bit Key-ID field 1604 and a 8-bit Algorithm-ID field. 1606 o Move the control-plane codepoints from the IANA Considerations 1607 section of RFC6830bis to the IANA Considerations section of this 1608 document. 1610 o In the "LISP Control Packet Type Allocations" section, indicate 1611 how message Types are IANA allocated and how experimental RFC8113 1612 sub-types should be requested. 1614 B.3. Changes to draft-ietf-lisp-rfc6833bis-03 1616 o Posted April 2017. 1618 o Add types 9-14 and specify they are not assigned. 1620 o Add the "LISP Shared Extension Message" type and point to RFC8113. 1622 B.4. Changes to draft-ietf-lisp-rfc6833bis-02 1624 o Posted April 2017. 1626 o Clarify that the LISP control-plane document defines how the LISP 1627 data-plane uses Map-Requests with either the SMR-bit set or the 1628 P-bit set supporting mapping updates and RLOC-probing. Indicating 1629 that other data-planes can use the same mechanisms or their own 1630 defined mechanisms to achieve the same functionality. 1632 B.5. Changes to draft-ietf-lisp-rfc6833bis-01 1634 o Posted March 2017. 1636 o Include references to new RFCs published. 1638 o Remove references to self. 1640 o Change references from RFC6830 to RFC6830bis. 1642 o Add two new action/reasons to a Map-Reply has posted to the LISP 1643 WG mailing list. 1645 o In intro section, add refernece to I-D.ietf-lisp-introduction. 1647 o Removed Open Issues section and references to "experimental". 1649 B.6. Changes to draft-ietf-lisp-rfc6833bis-00 1651 o Posted December 2016. 1653 o Created working group document from draft-farinacci-lisp 1654 -rfc6833-00 individual submission. No other changes made. 1656 B.7. Changes to draft-farinacci-lisp-rfc6833bis-00 1658 o Posted November 2016. 1660 o This is the initial draft to turn RFC 6833 into RFC 6833bis. 1662 o The document name has changed from the "Locator/ID Separation 1663 Protocol (LISP) Map-Server Interface" to the "Locator/ID 1664 Separation Protocol (LISP) Control-Plane". 1666 o The fundamental change was to move the control-plane messages from 1667 RFC 6830 to this document in an effort so any IETF developed or 1668 industry created data-plane could use the LISP mapping system and 1669 control-plane. 1671 o Update control-plane messages to incorporate what has been 1672 implemented in products during the early phase of LISP development 1673 but wasn't able to make it into RFC6830 and RFC6833 to make the 1674 Experimental RFC deadline. 1676 o Indicate there may be nodes in the mapping system that are not MRs 1677 or MSs, that is a ALT-node or a DDT-node. 1679 o Include LISP-DDT in Map-Resolver section and explain how they 1680 maintain a referral-cache. 1682 o Removed open issue about additional state in Map-Servers. With 1683 [I-D.ietf-lisp-ddt], Map-Servers have the same registration state 1684 and can give Map-Resolvers complete information in ms-ack Map- 1685 Referral messages. 1687 o Make reference to the LISP Threats Analysis RFC [RFC7835]. 1689 Authors' Addresses 1691 Vince Fuller 1692 Cisco Systems 1694 EMail: vaf@vaf.net 1696 Dino Farinacci 1697 Cisco Systems 1699 EMail: farinacci@gmail.com 1701 Albert Cabellos 1702 UPC/BarcelonaTech 1703 Campus Nord, C. Jordi Girona 1-3 1704 Barcelona, Catalunya 1705 Spain 1707 EMail: acabello@ac.upc.edu