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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: April 8, 2018 A. Cabellos (Ed.) 6 UPC/BarcelonaTech 7 October 5, 2017 9 Locator/ID Separation Protocol (LISP) Control-Plane 10 draft-ietf-lisp-rfc6833bis-06 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 https://datatracker.ietf.org/drafts/current/. 40 Internet-Drafts are draft documents valid for a maximum of six months 41 and may be updated, replaced, or obsoleted by other documents at any 42 time. It is inappropriate to use Internet-Drafts as reference 43 material or to cite them other than as "work in progress." 45 This Internet-Draft will expire on April 8, 2018. 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 (https://trustee.ietf.org/license-info) in effect on the date of 55 publication of this document. Please review these documents 56 carefully, as they describe your rights and restrictions with respect 57 to this document. Code Components extracted from this document must 58 include Simplified BSD License text as described in Section 4.e of 59 the Trust Legal Provisions and are provided without warranty as 60 described in the Simplified BSD License. 62 Table of Contents 64 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 65 2. 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 . . . . . . . . . . . 13 71 4.4. Map-Reply Message Format . . . . . . . . . . . . . . . . 15 72 4.5. EID-to-RLOC UDP Map-Reply Message . . . . . . . . . . . . 19 73 4.6. Map-Register Message Format . . . . . . . . . . . . . . . 22 74 4.7. Map-Notify/Map-Notify-Ack Message Format . . . . . . . . 25 75 4.8. Encapsulated Control Message Format . . . . . . . . . . . 26 76 5. Interactions with Other LISP Components . . . . . . . . . . . 28 77 5.1. ITR EID-to-RLOC Mapping Resolution . . . . . . . . . . . 28 78 5.2. EID-Prefix Configuration and ETR Registration . . . . . . 29 79 5.3. Map-Server Processing . . . . . . . . . . . . . . . . . . 31 80 5.4. Map-Resolver Processing . . . . . . . . . . . . . . . . . 31 81 5.4.1. Anycast Map-Resolver Operation . . . . . . . . . . . 32 82 6. Security Considerations . . . . . . . . . . . . . . . . . . . 32 83 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 33 84 7.1. LISP Packet Type Codes . . . . . . . . . . . . . . . . . 33 85 7.2. LISP ACT and Flag Fields . . . . . . . . . . . . . . . . 33 86 7.3. LISP Address Type Codes . . . . . . . . . . . . . . . . . 34 87 7.4. LISP Algorithm ID Numbers . . . . . . . . . . . . . . . . 34 88 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 34 89 8.1. Normative References . . . . . . . . . . . . . . . . . . 34 90 8.2. Informative References . . . . . . . . . . . . . . . . . 36 91 Appendix A. Acknowledgments . . . . . . . . . . . . . . . . . . 39 92 Appendix B. Document Change Log . . . . . . . . . . . . . . . . 39 93 B.1. Changes to draft-ietf-lisp-rfc6833bis-06 . . . . . . . . 39 94 B.2. Changes to draft-ietf-lisp-rfc6833bis-05 . . . . . . . . 39 95 B.3. Changes to draft-ietf-lisp-rfc6833bis-04 . . . . . . . . 39 96 B.4. Changes to draft-ietf-lisp-rfc6833bis-03 . . . . . . . . 40 97 B.5. Changes to draft-ietf-lisp-rfc6833bis-02 . . . . . . . . 40 98 B.6. Changes to draft-ietf-lisp-rfc6833bis-01 . . . . . . . . 40 99 B.7. Changes to draft-ietf-lisp-rfc6833bis-00 . . . . . . . . 40 100 B.8. Changes to draft-farinacci-lisp-rfc6833bis-00 . . . . . . 41 101 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 41 103 1. Introduction 105 The Locator/ID Separation Protocol [I-D.ietf-lisp-introduction] and 106 [I-D.ietf-lisp-rfc6830bis] specifies an architecture and mechanism 107 for replacing the addresses currently used by IP with two separate 108 name spaces: Endpoint IDs (EIDs), used within sites; and Routing 109 Locators (RLOCs), used on the transit networks that make up the 110 Internet infrastructure. To achieve this separation, LISP defines 111 protocol mechanisms for mapping from EIDs to RLOCs. In addition, 112 LISP assumes the existence of a database to store and propagate those 113 mappings globally. Several such databases have been proposed; among 114 them are the Content distribution Overlay Network Service for LISP 115 (LISP-CONS) [LISP-CONS], LISP-NERD (a Not-so-novel EID-to-RLOC 116 Database) [RFC6837], LISP Alternative Logical Topology (LISP+ALT) 117 [RFC6836], and LISP Delegated Database Tree (LISP-DDT) [RFC8111]. 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 [RFC8111] is used as the mapping database, a Map-Server 215 sends the final Map-Referral messages from the Delegated Database 216 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 [RFC8111], a Map- 226 Resolver maintains a referral-cache and acts as a "first-hop" DDT- 227 node. The Map-Resolver uses the referral information to forward Map- 228 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|I| Rsvd |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 I: This is the xTR-ID bit. When this bit is set, what is appended to 426 the Map-Request is a 128-bit xTR router-ID. See LISP PubSub usage 427 procedures in [I-D.rodrigueznatal-lisp-pubsub] for details. 429 Rsvd: This field MUST be set to 0 on transmit and MUST be ignored on 430 receipt. 432 L: This is the local-xtr bit. It is used by an xTR in a LISP site to 433 tell other xTRs in the same site that it is local to the site. 434 That is, that it is part of the RLOC-set for the LISP site. 436 D: This is the dont-map-reply bit. It is used in the SMR procedure 437 described in [I-D.ietf-lisp-rfc6830bis]. When an xTR sends an SMR 438 Map-Request message, it doesn't need a Map-Reply returned. When 439 this bit is set, the receiver of the Map-Request does not return a 440 Map-Reply. 442 IRC: This 5-bit field is the ITR-RLOC Count, which encodes the 443 additional number of ('ITR-RLOC-AFI', 'ITR-RLOC Address') fields 444 present in this message. At least one (ITR-RLOC-AFI, ITR-RLOC- 445 Address) pair MUST be encoded. Multiple 'ITR-RLOC Address' fields 446 are used, so a Map-Replier can select which destination address to 447 use for a Map-Reply. The IRC value ranges from 0 to 31. For a 448 value of 0, there is 1 ITR-RLOC address encoded; for a value of 1, 449 there are 2 ITR-RLOC addresses encoded, and so on up to 31, which 450 encodes a total of 32 ITR-RLOC addresses. 452 Record Count: This is the number of records in this Map-Request 453 message. A record is comprised of the portion of the packet that 454 is labeled 'Rec' above and occurs the number of times equal to 455 Record Count. For this version of the protocol, a receiver MUST 456 accept and process Map-Requests that contain one or more records, 457 but a sender MUST only send Map-Requests containing one record. 458 Support for requesting multiple EIDs in a single Map-Request 459 message will be specified in a future version of the protocol. 461 Nonce: This is an 8-octet random value created by the sender of the 462 Map-Request. This nonce will be returned in the Map-Reply. The 463 security of the LISP mapping protocol critically depends on the 464 strength of the nonce in the Map-Request message. The nonce 465 SHOULD be generated by a properly seeded pseudo-random (or strong 466 random) source. See [RFC4086] for advice on generating security- 467 sensitive random data. 469 Source-EID-AFI: This is the address family of the 'Source EID 470 Address' field. 472 Source EID Address: This is the EID of the source host that 473 originated the packet that caused the Map-Request. When Map- 474 Requests are used for refreshing a Map-Cache entry or for RLOC- 475 Probing, an AFI value 0 is used and this field is of zero length. 477 ITR-RLOC-AFI: This is the address family of the 'ITR-RLOC Address' 478 field that follows this field. 480 ITR-RLOC Address: This is used to give the ETR the option of 481 selecting the destination address from any address family for the 482 Map-Reply message. This address MUST be a routable RLOC address 483 of the sender of the Map-Request message. 485 EID mask-len: This is the mask length for the EID-Prefix. 487 EID-Prefix-AFI: This is the address family of the EID-Prefix 488 according to [AFI] and [RFC8060]. 490 EID-Prefix: This prefix is 4 octets for an IPv4 address family and 491 16 octets for an IPv6 address family. When a Map-Request is sent 492 by an ITR because a data packet is received for a destination 493 where there is no mapping entry, the EID-Prefix is set to the 494 destination IP address of the data packet, and the 'EID mask-len' 495 is set to 32 or 128 for IPv4 or IPv6, respectively. When an xTR 496 wants to query a site about the status of a mapping it already has 497 cached, the EID-Prefix used in the Map-Request has the same mask 498 length as the EID-Prefix returned from the site when it sent a 499 Map-Reply message. 501 Map-Reply Record: When the M-bit is set, this field is the size of a 502 single "Record" in the Map-Reply format. This Map-Reply record 503 contains the EID-to-RLOC mapping entry associated with the Source 504 EID. This allows the ETR that will receive this Map-Request to 505 cache the data if it chooses to do so. 507 4.3. EID-to-RLOC UDP Map-Request Message 509 A Map-Request is sent from an ITR when it needs a mapping for an EID, 510 wants to test an RLOC for reachability, or wants to refresh a mapping 511 before TTL expiration. For the initial case, the destination IP 512 address used for the Map-Request is the data packet's destination 513 address (i.e., the destination EID) that had a mapping cache lookup 514 failure. For the latter two cases, the destination IP address used 515 for the Map-Request is one of the RLOC addresses from the Locator-Set 516 of the Map-Cache entry. The source address is either an IPv4 or IPv6 517 RLOC address, depending on whether the Map-Request is using an IPv4 518 or IPv6 header, respectively. In all cases, the UDP source port 519 number for the Map-Request message is a 16-bit value selected by the 520 ITR/PITR, and the UDP destination port number is set to the well- 521 known destination port number 4342. A successful Map-Reply, which is 522 one that has a nonce that matches an outstanding Map-Request nonce, 523 will update the cached set of RLOCs associated with the EID-Prefix 524 range. 526 One or more Map-Request ('ITR-RLOC-AFI', 'ITR-RLOC-Address') fields 527 MUST be filled in by the ITR. The number of fields (minus 1) encoded 528 MUST be placed in the 'IRC' field. The ITR MAY include all locally 529 configured Locators in this list or just provide one locator address 530 from each address family it supports. If the ITR erroneously 531 provides no ITR-RLOC addresses, the Map-Replier MUST drop the Map- 532 Request. 534 Map-Requests can also be LISP encapsulated using UDP destination 535 port 4342 with a LISP Type value set to "Encapsulated Control 536 Message", when sent from an ITR to a Map-Resolver. Likewise, Map- 537 Requests are LISP encapsulated the same way from a Map-Server to an 538 ETR. Details on Encapsulated Map-Requests and Map-Resolvers can be 539 found in Section 4.8. 541 Map-Requests MUST be rate-limited. It is RECOMMENDED that a Map- 542 Request for the same EID-Prefix be sent no more than once per second. 544 An ITR that is configured with mapping database information (i.e., it 545 is also an ETR) MAY optionally include those mappings in a Map- 546 Request. When an ETR configured to accept and verify such 547 "piggybacked" mapping data receives such a Map-Request and it does 548 not have this mapping in the map-cache, it MAY originate a "verifying 549 Map-Request", addressed to the map-requesting ITR and the ETR MAY add 550 a Map-Cache entry. If the ETR has a Map-Cache entry that matches the 551 "piggybacked" EID and the RLOC is in the Locator-Set for the entry, 552 then it may send the "verifying Map-Request" directly to the 553 originating Map-Request source. If the RLOC is not in the Locator- 554 Set, then the ETR MUST send the "verifying Map-Request" to the 555 "piggybacked" EID. Doing this forces the "verifying Map-Request" to 556 go through the mapping database system to reach the authoritative 557 source of information about that EID, guarding against RLOC-spoofing 558 in the "piggybacked" mapping data. 560 4.4. Map-Reply Message Format 562 0 1 2 3 563 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 1 564 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 565 |Type=2 |P|E|S| Reserved | Record Count | 566 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 567 | Nonce . . . | 568 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 569 | . . . Nonce | 570 +-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 571 | | Record TTL | 572 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 573 R | Locator Count | EID mask-len | ACT |A| Reserved | 574 e +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 575 c | Rsvd | Map-Version Number | EID-Prefix-AFI | 576 o +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 577 r | EID-Prefix | 578 d +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 579 | /| Priority | Weight | M Priority | M Weight | 580 | L +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 581 | o | Unused Flags |L|p|R| Loc-AFI | 582 | c +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 583 | \| Locator | 584 +-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 586 Packet field descriptions: 588 Type: 2 (Map-Reply) 590 P: This is the probe-bit, which indicates that the Map-Reply is in 591 response to a Locator reachability probe Map-Request. The 'Nonce' 592 field MUST contain a copy of the nonce value from the original 593 Map-Request. See RLOC-probing [I-D.ietf-lisp-rfc6830bis] for more 594 details. 596 E: This bit indicates that the ETR that sends this Map-Reply message 597 is advertising that the site is enabled for the Echo-Nonce Locator 598 reachability algorithm. See Echo-Nonce [I-D.ietf-lisp-rfc6830bis] 599 for more details. 601 S: This is the Security bit. When set to 1, the following 602 authentication information will be appended to the end of the Map- 603 Reply. The details of signing a Map-Reply message can be found in 604 [I-D.ietf-lisp-sec]. 606 0 1 2 3 607 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 1 608 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 609 | AD Type | Authentication Data Content . . . | 610 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 612 Reserved: This field MUST be set to 0 on transmit and MUST be 613 ignored on receipt. 615 Record Count: This is the number of records in this reply message. 616 A record is comprised of that portion of the packet labeled 617 'Record' above and occurs the number of times equal to Record 618 Count. 620 Nonce: This is a 24-bit value set in a Data-Probe packet, or a 621 64-bit value from the Map-Request is echoed in this 'Nonce' field 622 of the Map-Reply. When a 24-bit value is supplied, it resides in 623 the low-order 64 bits of the 'Nonce' field. 625 Record TTL: This is the time in minutes the recipient of the Map- 626 Reply will store the mapping. If the TTL is 0, the entry SHOULD 627 be removed from the cache immediately. If the value is 628 0xffffffff, the recipient can decide locally how long to store the 629 mapping. 631 Locator Count: This is the number of Locator entries. A Locator 632 entry comprises what is labeled above as 'Loc'. The Locator count 633 can be 0, indicating that there are no Locators for the EID- 634 Prefix. 636 EID mask-len: This is the mask length for the EID-Prefix. 638 ACT: This 3-bit field describes Negative Map-Reply actions. In any 639 other message type, these bits are set to 0 and ignored on 640 receipt. These bits are used only when the 'Locator Count' field 641 is set to 0. The action bits are encoded only in Map-Reply 642 messages. The actions defined are used by an ITR or PITR when a 643 destination EID matches a negative Map-Cache entry. Unassigned 644 values should cause a Map-Cache entry to be created, and when 645 packets match this negative cache entry, they will be dropped. 646 The current assigned values are: 648 (0) No-Action: The map-cache is kept alive, and no packet 649 encapsulation occurs. 651 (1) Natively-Forward: The packet is not encapsulated or dropped 652 but natively forwarded. 654 (2) Send-Map-Request: The packet invokes sending a Map-Request. 656 (3) Drop/No-Reason: A packet that matches this map-cache entry is 657 dropped. An ICMP Destination Unreachable message SHOULD be 658 sent. 660 (4) Drop/Policy-Denied: A packet that matches this map-cache 661 entry is dropped. The reason for the Drop action is that a 662 Map-Request for the target-EID is being policy denied by 663 either an xTR or the mapping system. 665 (5) Drop/Authentication-Failure: A packet that matches this map- 666 cache entry is dropped. The reason for the Drop action is 667 that a Map-Request for the target-EID fails an authentication 668 verification-check by either an xTR or the mapping system. 670 A: The Authoritative bit, when sent, is always set to 1 by an ETR. 671 When a Map-Server is proxy Map-Replying for a LISP site, the 672 Authoritative bit is set to 0. This indicates to requesting ITRs 673 that the Map-Reply was not originated by a LISP node managed at 674 the site that owns the EID-Prefix. 676 Map-Version Number: When this 12-bit value is non-zero, the Map- 677 Reply sender is informing the ITR what the version number is for 678 the EID record contained in the Map-Reply. The ETR can allocate 679 this number internally but MUST coordinate this value with other 680 ETRs for the site. When this value is 0, there is no versioning 681 information conveyed. The Map-Version Number can be included in 682 Map-Request and Map-Register messages. See Map-Versioning 683 [I-D.ietf-lisp-rfc6830bis] for more details. 685 EID-Prefix-AFI: Address family of the EID-Prefix according to [AFI] 686 and [RFC8060]. 688 EID-Prefix: This prefix is 4 octets for an IPv4 address family and 689 16 octets for an IPv6 address family. 691 Priority: Each RLOC is assigned a unicast Priority. Lower values 692 are more preferable. When multiple RLOCs have the same Priority, 693 they MAY be used in a load-split fashion. A value of 255 means 694 the RLOC MUST NOT be used for unicast forwarding. 696 Weight: When priorities are the same for multiple RLOCs, the Weight 697 indicates how to balance unicast traffic between them. Weight is 698 encoded as a relative weight of total unicast packets that match 699 the mapping entry. For example, if there are 4 Locators in a 700 Locator-Set, where the Weights assigned are 30, 20, 20, and 10, 701 the first Locator will get 37.5% of the traffic, the 2nd and 3rd 702 Locators will get 25% of the traffic, and the 4th Locator will get 703 12.5% of the traffic. If all Weights for a Locator-Set are equal, 704 the receiver of the Map-Reply will decide how to load-split the 705 traffic. See RLOC-hashing [I-D.ietf-lisp-rfc6830bis] for a 706 suggested hash algorithm to distribute the load across Locators 707 with the same Priority and equal Weight values. 709 M Priority: Each RLOC is assigned a multicast Priority used by an 710 ETR in a receiver multicast site to select an ITR in a source 711 multicast site for building multicast distribution trees. A value 712 of 255 means the RLOC MUST NOT be used for joining a multicast 713 distribution tree. For more details, see [RFC6831]. 715 M Weight: When priorities are the same for multiple RLOCs, the 716 Weight indicates how to balance building multicast distribution 717 trees across multiple ITRs. The Weight is encoded as a relative 718 weight (similar to the unicast Weights) of the total number of 719 trees built to the source site identified by the EID-Prefix. If 720 all Weights for a Locator-Set are equal, the receiver of the Map- 721 Reply will decide how to distribute multicast state across ITRs. 722 For more details, see [RFC6831]. 724 Unused Flags: These are set to 0 when sending and ignored on 725 receipt. 727 L: When this bit is set, the Locator is flagged as a local Locator to 728 the ETR that is sending the Map-Reply. When a Map-Server is doing 729 proxy Map-Replying for a LISP site, the L-bit is set to 0 for all 730 Locators in this Locator-Set. 732 p: When this bit is set, an ETR informs the RLOC-Probing ITR that the 733 locator address for which this bit is set is the one being RLOC- 734 probed and MAY be different from the source address of the Map- 735 Reply. An ITR that RLOC-probes a particular Locator MUST use this 736 Locator for retrieving the data structure used to store the fact 737 that the Locator is reachable. The p-bit is set for a single 738 Locator in the same Locator-Set. If an implementation sets more 739 than one p-bit erroneously, the receiver of the Map-Reply MUST 740 select the first Locator. The p-bit MUST NOT be set for Locator- 741 Set records sent in Map-Request and Map-Register messages. 743 R: This is set when the sender of a Map-Reply has a route to the 744 Locator in the Locator data record. This receiver may find this 745 useful to know if the Locator is up but not necessarily reachable 746 from the receiver's point of view. See also EID-Reachability 747 [I-D.ietf-lisp-rfc6830bis] for another way the R-bit may be used. 749 Locator: This is an IPv4 or IPv6 address (as encoded by the 'Loc- 750 AFI' field) assigned to an ETR. Note that the destination RLOC 751 address MAY be an anycast address. A source RLOC can be an 752 anycast address as well. The source or destination RLOC MUST NOT 753 be the broadcast address (255.255.255.255 or any subnet broadcast 754 address known to the router) and MUST NOT be a link-local 755 multicast address. The source RLOC MUST NOT be a multicast 756 address. The destination RLOC SHOULD be a multicast address if it 757 is being mapped from a multicast destination EID. 759 4.5. EID-to-RLOC UDP Map-Reply Message 761 A Map-Reply returns an EID-Prefix with a prefix length that is less 762 than or equal to the EID being requested. The EID being requested is 763 either from the destination field of an IP header of a Data-Probe or 764 the EID record of a Map-Request. The RLOCs in the Map-Reply are 765 globally routable IP addresses of all ETRs for the LISP site. Each 766 RLOC conveys status reachability but does not convey path 767 reachability from a requester's perspective. Separate testing of 768 path reachability is required. See RLOC-reachability 769 [I-D.ietf-lisp-rfc6830bis] for details. 771 Note that a Map-Reply may contain different EID-Prefix granularity 772 (prefix + length) than the Map-Request that triggers it. This might 773 occur if a Map-Request were for a prefix that had been returned by an 774 earlier Map-Reply. In such a case, the requester updates its cache 775 with the new prefix information and granularity. For example, a 776 requester with two cached EID-Prefixes that are covered by a Map- 777 Reply containing one less-specific prefix replaces the entry with the 778 less-specific EID-Prefix. Note that the reverse, replacement of one 779 less-specific prefix with multiple more-specific prefixes, can also 780 occur, not by removing the less-specific prefix but rather by adding 781 the more-specific prefixes that, during a lookup, will override the 782 less-specific prefix. 784 When an ETR is configured with overlapping EID-Prefixes, a Map- 785 Request with an EID that best matches any EID-Prefix MUST be returned 786 in a single Map-Reply message. For instance, if an ETR had database 787 mapping entries for EID-Prefixes: 789 10.0.0.0/8 790 10.1.0.0/16 791 10.1.1.0/24 792 10.1.2.0/24 794 A Map-Request for EID 10.1.1.1 would cause a Map-Reply with a record 795 count of 1 to be returned with a mapping record EID-Prefix of 796 10.1.1.0/24. 798 A Map-Request for EID 10.1.5.5 would cause a Map-Reply with a record 799 count of 3 to be returned with mapping records for EID-Prefixes 800 10.1.0.0/16, 10.1.1.0/24, and 10.1.2.0/24. 802 Note that not all overlapping EID-Prefixes need to be returned but 803 only the more-specific entries (note that in the second example above 804 10.0.0.0/8 was not returned for requesting EID 10.1.5.5) for the 805 matching EID-Prefix of the requesting EID. When more than one EID- 806 Prefix is returned, all SHOULD use the same Time to Live value so 807 they can all time out at the same time. When a more-specific EID- 808 Prefix is received later, its Time to Live value in the Map-Reply 809 record can be stored even when other less-specific entries exist. 810 When a less-specific EID-Prefix is received later, its map-cache 811 expiration time SHOULD be set to the minimum expiration time of any 812 more-specific EID-Prefix in the map-cache. This is done so the 813 integrity of the EID-Prefix set is wholly maintained and so no more- 814 specific entries are removed from the map-cache while keeping less- 815 specific entries. 817 Map-Replies SHOULD be sent for an EID-Prefix no more often than once 818 per second to the same requesting router. For scalability, it is 819 expected that aggregation of EID addresses into EID-Prefixes will 820 allow one Map-Reply to satisfy a mapping for the EID addresses in the 821 prefix range, thereby reducing the number of Map-Request messages. 823 Map-Reply records can have an empty Locator-Set. A Negative Map- 824 Reply is a Map-Reply with an empty Locator-Set. Negative Map-Replies 825 convey special actions by the sender to the ITR or PITR that have 826 solicited the Map-Reply. There are two primary applications for 827 Negative Map-Replies. The first is for a Map-Resolver to instruct an 828 ITR or PITR when a destination is for a LISP site versus a non-LISP 829 site, and the other is to source quench Map-Requests that are sent 830 for non-allocated EIDs. 832 For each Map-Reply record, the list of Locators in a Locator-Set MUST 833 appear in the same order for each ETR that originates a Map-Reply 834 message. The Locator-Set MUST be sorted in order of ascending IP 835 address where an IPv4 locator address is considered numerically 'less 836 than' an IPv6 locator address. 838 When sending a Map-Reply message, the destination address is copied 839 from one of the 'ITR-RLOC' fields from the Map-Request. The ETR can 840 choose a locator address from one of the address families it 841 supports. For Data-Probes, the destination address of the Map-Reply 842 is copied from the source address of the Data-Probe message that is 843 invoking the reply. The source address of the Map-Reply is one of 844 the local IP addresses chosen to allow Unicast Reverse Path 845 Forwarding (uRPF) checks to succeed in the upstream service provider. 846 The destination port of a Map-Reply message is copied from the source 847 port of the Map-Request or Data-Probe, and the source port of the 848 Map-Reply message is set to the well-known UDP port 4342. 850 4.6. Map-Register Message Format 852 This section specifies the encoding format for the Map-Register 853 message. The message is sent in UDP with a destination UDP port of 854 4342 and a randomly selected UDP source port number. 856 The Map-Register message format is: 858 0 1 2 3 859 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 1 860 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 861 |Type=3 |P|S|I| Reserved |E|T|a|m|M| Record Count | 862 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 863 | Nonce . . . | 864 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 865 | . . . Nonce | 866 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 867 | Key ID | Algorithm ID | Authentication Data Length | 868 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 869 ~ Authentication Data ~ 870 +-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 871 | | Record TTL | 872 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 873 R | Locator Count | EID mask-len | ACT |A| Reserved | 874 e +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 875 c | Rsvd | Map-Version Number | EID-Prefix-AFI | 876 o +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 877 r | EID-Prefix | 878 d +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 879 | /| Priority | Weight | M Priority | M Weight | 880 | L +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 881 | o | Unused Flags |L|p|R| Loc-AFI | 882 | c +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 883 | \| Locator | 884 +-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 886 Packet field descriptions: 888 Type: 3 (Map-Register) 890 P: This is the proxy Map-Reply bit. When set to 1, an ETR sends a 891 Map-Register message requesting the Map-Server to proxy a Map- 892 Reply. The Map-Server will send non-authoritative Map-Replies on 893 behalf of the ETR. 895 S: This is the security-capable bit. When set, the procedures from 896 [I-D.ietf-lisp-sec] are supported. 898 I: This is the xTR-ID bit. When this bit is set, what is appended to 899 the Map-Register is a 128-bit xTR router-ID and then a 64-bit 900 site-ID. See LISP NAT-Traversal procedures in 901 [I-D.ermagan-lisp-nat-traversal] for details. 903 Reserved: This field MUST be set to 0 on transmit and MUST be 904 ignored on receipt. 906 E: This is the Map-Register EID-notify bit. This is used by a First- 907 Hop-Router (FHR) which discovers a dynamic-EID. This EID-notify 908 based Map-Register is sent by the FHR to the same site xTR that 909 propogates the Map-Register to the mapping system. The site xTR 910 keeps state to later Map-Notify the FHR after the EID has moves 911 away. See [I-D.ietf-lisp-eid-mobility] for a detailed use-case. 913 T: This is the use-TTL for timeout bit. When set to 1, the xTR wants 914 the Map-Server to time out registrations based on the value in the 915 "Record TTL" field of this message. 917 a: This is the merge-request bit. When set to 1, the xTR requests to 918 merge RLOC-records from different xTRs registering the same EID- 919 record. See signal-free multicast 920 [I-D.ietf-lisp-signal-free-multicast] for one use case example. 922 m: This is the mobile-node bit. When set to 1, the registering xTR 923 supports the procedures in [I-D.ietf-lisp-mn]. 925 M: This is the want-map-notify bit. When set to 1, an ETR is 926 requesting a Map-Notify message to be returned in response to 927 sending a Map-Register message. The Map-Notify message sent by a 928 Map-Server is used to acknowledge receipt of a Map-Register 929 message. 931 Record Count: This is the number of records in this Map-Register 932 message. A record is comprised of that portion of the packet 933 labeled 'Record' above and occurs the number of times equal to 934 Record Count. 936 Nonce: This 8-octet 'Nonce' field is set to 0 in Map-Register 937 messages. Since the Map-Register message is authenticated, the 938 'Nonce' field is not currently used for any security function but 939 may be in the future as part of an anti-replay solution. 941 Key ID: This is a configured key-id value that corresponds to a 942 shared-secret password that is used to authenticate the sender. 943 Multiple shared-secrets can be used to roll over keys in a non- 944 disruptive way. 946 Algorithm ID: This is the configured Message Authentication Code 947 (MAC) algorithm value used for the authentication function. See 948 Algorithm ID Numbers in the Section 7.3 for codepoint assignments. 950 Authentication Data Length: This is the length in octets of the 951 'Authentication Data' field that follows this field. The length 952 of the 'Authentication Data' field is dependent on the MAC 953 algorithm used. The length field allows a device that doesn't 954 know the MAC algorithm to correctly parse the packet. 956 Authentication Data: This is the message digest used from the output 957 of the MAC algorithm. The entire Map-Register payload is 958 authenticated with this field preset to 0. After the MAC is 959 computed, it is placed in this field. Implementations of this 960 specification MUST include support for HMAC-SHA-1-96 [RFC2404], 961 and support for HMAC-SHA-256-128 [RFC4868] is RECOMMENDED. 963 The definition of the rest of the Map-Register can be found in 964 Section 4.4. 966 4.7. Map-Notify/Map-Notify-Ack Message Format 968 This section specifies the encoding format for the Map-Notify and 969 Map-Notify-Ack messages. The messages are sent inside a UDP packet 970 with source and destination UDP ports equal to 4342. 972 The Map-Notify and Map-Notify-Ack message formats are: 974 0 1 2 3 975 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 1 976 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 977 |Type=4/5| Reserved | Record Count | 978 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 979 | Nonce . . . | 980 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 981 | . . . Nonce | 982 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 983 | Key ID | Algorithm ID | Authentication Data Length | 984 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 985 ~ Authentication Data ~ 986 +-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 987 | | Record TTL | 988 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 989 R | Locator Count | EID mask-len | ACT |A| Reserved | 990 e +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 991 c | Rsvd | Map-Version Number | EID-Prefix-AFI | 992 o +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 993 r | EID-Prefix | 994 d +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 995 | /| Priority | Weight | M Priority | M Weight | 996 | L +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 997 | o | Unused Flags |L|p|R| Loc-AFI | 998 | c +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 999 | \| Locator | 1000 +-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1002 Packet field descriptions: 1004 Type: 4/5 (Map-Notify/Map-Notify-Ack) 1006 The Map-Notify message has the same contents as a Map-Register 1007 message. See the Map-Register section for field descriptions. 1009 The Map-Notify-Ack message has the same contents as a Map-Notify 1010 message. It is used to acknowledge the receipt of a Map-Notify and 1011 for the sender to stop retransmitting a Map-Notify with the same 1012 nonce. 1014 4.8. Encapsulated Control Message Format 1016 An Encapsulated Control Message (ECM) is used to encapsulate control 1017 packets sent between xTRs and the mapping database system. 1019 0 1 2 3 1020 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 1021 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1022 / | IPv4 or IPv6 Header | 1023 OH | (uses RLOC addresses) | 1024 \ | | 1025 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1026 / | Source Port = xxxx | Dest Port = 4342 | 1027 UDP +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1028 \ | UDP Length | UDP Checksum | 1029 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1030 LH |Type=8 |S|D|E|M| Reserved | 1031 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1032 / | IPv4 or IPv6 Header | 1033 IH | (uses RLOC or EID addresses) | 1034 \ | | 1035 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1036 / | Source Port = xxxx | Dest Port = yyyy | 1037 UDP +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1038 \ | UDP Length | UDP Checksum | 1039 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1040 LCM | LISP Control Message | 1041 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1043 Packet header descriptions: 1045 OH: The outer IPv4 or IPv6 header, which uses RLOC addresses in the 1046 source and destination header address fields. 1048 UDP: The outer UDP header with destination port 4342. The source 1049 port is randomly allocated. The checksum field MUST be non- 1050 zero. 1052 LH: Type 8 is defined to be a "LISP Encapsulated Control Message", 1053 and what follows is either an IPv4 or IPv6 header as encoded by 1054 the first 4 bits after the 'Reserved' field. 1056 Type: 8 (Encapsulated Control Message (ECM)) 1058 S: This is the Security bit. When set to 1, the procedures from 1059 [I-D.ietf-lisp-sec] are followed. 1061 D: This is the DDT-bit. When set to 1, the sender is requesting a 1062 Map-Referral message to be returned. The details of this 1063 procedure are described in [RFC8111]. 1065 E: This is the to-ETR bit. When set to 1, the Map-Server's 1066 intention is to forward the ECM to an authoritative ETR. 1068 M: This is the to-MS bit. When set to 1, a Map-Request is being 1069 sent to a co-located Map-Resolver and Map-Server where the 1070 message can be processed directly by the Map-Server versus the 1071 Map-Resolver using the LISP-DDT procedures in [RFC8111]. 1073 0 1 2 3 1074 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 1075 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1076 | AD Type | Authentication Data Content . . . | 1077 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1079 IH: The inner IPv4 or IPv6 header, which can use either RLOC or EID 1080 addresses in the header address fields. When a Map-Request is 1081 encapsulated in this packet format, the destination address in 1082 this header is an EID. 1084 UDP: The inner UDP header, where the port assignments depend on the 1085 control packet being encapsulated. When the control packet is 1086 a Map-Request or Map-Register, the source port is selected by 1087 the ITR/PITR and the destination port is 4342. When the 1088 control packet is a Map-Reply, the source port is 4342 and the 1089 destination port is assigned from the source port of the 1090 invoking Map-Request. Port number 4341 MUST NOT be assigned to 1091 either port. The checksum field MUST be non-zero. 1093 LCM: The format is one of the control message formats described in 1094 this section. At this time, only Map-Request messages are 1095 allowed to be encapsulated. In the future, PIM Join/Prune 1096 messages [RFC6831] might be allowed. Encapsulating other types 1097 of LISP control messages is for further study. When Map- 1098 Requests are sent for RLOC-Probing purposes (i.e., the probe- 1099 bit is set), they MUST NOT be sent inside Encapsulated Control 1100 Messages. 1102 5. Interactions with Other LISP Components 1104 5.1. ITR EID-to-RLOC Mapping Resolution 1106 An ITR is configured with one or more Map-Resolver addresses. These 1107 addresses are "Locators" (or RLOCs) and must be routable on the 1108 underlying core network; they must not need to be resolved through 1109 LISP EID-to-RLOC mapping, as that would introduce a circular 1110 dependency. When using a Map-Resolver, an ITR does not need to 1111 connect to any other database mapping system. In particular, the ITR 1112 need not connect to the LISP+ALT infrastructure or implement the BGP 1113 and GRE protocols that it uses. 1115 An ITR sends an Encapsulated Map-Request to a configured Map-Resolver 1116 when it needs an EID-to-RLOC mapping that is not found in its local 1117 map-cache. Using the Map-Resolver greatly reduces both the 1118 complexity of the ITR implementation and the costs associated with 1119 its operation. 1121 In response to an Encapsulated Map-Request, the ITR can expect one of 1122 the following: 1124 o An immediate Negative Map-Reply (with action code of "Natively- 1125 Forward", 15-minute Time to Live (TTL)) from the Map-Resolver if 1126 the Map-Resolver can determine that the requested EID does not 1127 exist. The ITR saves the EID-Prefix returned in the Map-Reply in 1128 its cache, marks it as non-LISP-capable, and knows not to attempt 1129 LISP encapsulation for destinations matching it. 1131 o A Negative Map-Reply, with action code of "Natively-Forward", from 1132 a Map-Server that is authoritative for an EID-Prefix that matches 1133 the requested EID but that does not have an actively registered, 1134 more-specific ID-prefix. In this case, the requested EID is said 1135 to match a "hole" in the authoritative EID-Prefix. If the 1136 requested EID matches a more-specific EID-Prefix that has been 1137 delegated by the Map-Server but for which no ETRs are currently 1138 registered, a 1-minute TTL is returned. If the requested EID 1139 matches a non-delegated part of the authoritative EID-Prefix, then 1140 it is not a LISP EID and a 15-minute TTL is returned. See 1141 Section 5.2 for discussion of aggregate EID-Prefixes and details 1142 of Map-Server EID-Prefix matching. 1144 o A LISP Map-Reply from the ETR that owns the EID-to-RLOC mapping or 1145 possibly from a Map-Server answering on behalf of the ETR. See 1146 Section 5.4 for more details on Map-Resolver message processing. 1148 Note that an ITR may be configured to both use a Map-Resolver and to 1149 participate in a LISP+ALT logical network. In such a situation, the 1150 ITR should send Map-Requests through the ALT network for any EID- 1151 Prefix learned via ALT BGP. Such a configuration is expected to be 1152 very rare, since there is little benefit to using a Map-Resolver if 1153 an ITR is already using LISP+ALT. There would be, for example, no 1154 need for such an ITR to send a Map-Request to a possibly non-existent 1155 EID (and rely on Negative Map-Replies) if it can consult the ALT 1156 database to verify that an EID-Prefix is present before sending that 1157 Map-Request. 1159 5.2. EID-Prefix Configuration and ETR Registration 1161 An ETR publishes its EID-Prefixes on a Map-Server by sending LISP 1162 Map-Register messages. A Map-Register message includes 1163 authentication data, so prior to sending a Map-Register message, the 1164 ETR and Map-Server must be configured with a shared secret or other 1165 relevant authentication information. A Map-Server's configuration 1166 must also include a list of the EID-Prefixes for which each ETR is 1167 authoritative. Upon receipt of a Map-Register from an ETR, a Map- 1168 Server accepts only EID-Prefixes that are configured for that ETR. 1169 Failure to implement such a check would leave the mapping system 1170 vulnerable to trivial EID-Prefix hijacking attacks. As developers 1171 and operators gain experience with the mapping system, additional, 1172 stronger security measures may be added to the registration process. 1174 In addition to the set of EID-Prefixes defined for each ETR that may 1175 register, a Map-Server is typically also configured with one or more 1176 aggregate prefixes that define the part of the EID numbering space 1177 assigned to it. When LISP+ALT is the database in use, aggregate EID- 1178 Prefixes are implemented as discard routes and advertised into ALT 1179 BGP. The existence of aggregate EID-Prefixes in a Map-Server's 1180 database means that it may receive Map Requests for EID-Prefixes that 1181 match an aggregate but do not match a registered prefix; Section 5.3 1182 describes how this is handled. 1184 Map-Register messages are sent periodically from an ETR to a Map- 1185 Server with a suggested interval between messages of one minute. A 1186 Map-Server should time out and remove an ETR's registration if it has 1187 not received a valid Map-Register message within the past 1188 three minutes. When first contacting a Map-Server after restart or 1189 changes to its EID-to-RLOC database mappings, an ETR may initially 1190 send Map-Register messages at an increased frequency, up to one every 1191 20 seconds. This "quick registration" period is limited to 1192 five minutes in duration. 1194 An ETR may request that a Map-Server explicitly acknowledge receipt 1195 and processing of a Map-Register message by setting the "want-map- 1196 notify" (M-bit) flag. A Map-Server that receives a Map-Register with 1197 this flag set will respond with a Map-Notify message. Typical use of 1198 this flag by an ETR would be to set it for Map-Register messages sent 1199 during the initial "quick registration" with a Map-Server but then 1200 set it only occasionally during steady-state maintenance of its 1201 association with that Map-Server. Note that the Map-Notify message 1202 is sent to UDP destination port 4342, not to the source port 1203 specified in the original Map-Register message. 1205 Note that a one-minute minimum registration interval during 1206 maintenance of an ETR-Map-Server association places a lower bound on 1207 how quickly and how frequently a mapping database entry can be 1208 updated. This may have implications for what sorts of mobility can 1209 be supported directly by the mapping system; shorter registration 1210 intervals or other mechanisms might be needed to support faster 1211 mobility in some cases. For a discussion on one way that faster 1212 mobility may be implemented for individual devices, please see 1213 [I-D.ietf-lisp-mn]. 1215 An ETR may also request, by setting the "proxy Map-Reply" flag 1216 (P-bit) in the Map-Register message, that a Map-Server answer Map- 1217 Requests instead of forwarding them to the ETR. See 1218 [I-D.ietf-lisp-rfc6830bis] for details on how the Map-Server sets 1219 certain flags (such as those indicating whether the message is 1220 authoritative and how returned Locators should be treated) when 1221 sending a Map-Reply on behalf of an ETR. When an ETR requests proxy 1222 reply service, it should include all RLOCs for all ETRs for the EID- 1223 Prefix being registered, along with the routable flag ("R-bit") 1224 setting for each RLOC. The Map-Server includes all of this 1225 information in Map-Reply messages that it sends on behalf of the ETR. 1226 This differs from a non-proxy registration, since the latter need 1227 only provide one or more RLOCs for a Map-Server to use for forwarding 1228 Map-Requests; the registration information is not used in Map- 1229 Replies, so it being incomplete is not incorrect. 1231 An ETR that uses a Map-Server to publish its EID-to-RLOC mappings 1232 does not need to participate further in the mapping database 1233 protocol(s). When using a LISP+ALT mapping database, for example, 1234 this means that the ETR does not need to implement GRE or BGP, which 1235 greatly simplifies its configuration and reduces its cost of 1236 operation. 1238 Note that use of a Map-Server does not preclude an ETR from also 1239 connecting to the mapping database (i.e., it could also connect to 1240 the LISP+ALT network), but doing so doesn't seem particularly useful, 1241 as the whole purpose of using a Map-Server is to avoid the complexity 1242 of the mapping database protocols. 1244 5.3. Map-Server Processing 1246 Once a Map-Server has EID-Prefixes registered by its client ETRs, it 1247 can accept and process Map-Requests for them. 1249 In response to a Map-Request (received over the ALT if LISP+ALT is in 1250 use), the Map-Server first checks to see if the destination EID 1251 matches a configured EID-Prefix. If there is no match, the Map- 1252 Server returns a Negative Map-Reply with action code "Natively- 1253 Forward" and a 15-minute TTL. This may occur if a Map Request is 1254 received for a configured aggregate EID-Prefix for which no more- 1255 specific EID-Prefix exists; it indicates the presence of a non-LISP 1256 "hole" in the aggregate EID-Prefix. 1258 Next, the Map-Server checks to see if any ETRs have registered the 1259 matching EID-Prefix. If none are found, then the Map-Server returns 1260 a Negative Map-Reply with action code "Natively-Forward" and a 1261 1-minute TTL. 1263 If any of the registered ETRs for the EID-Prefix have requested proxy 1264 reply service, then the Map-Server answers the request instead of 1265 forwarding it. It returns a Map-Reply with the EID-Prefix, RLOCs, 1266 and other information learned through the registration process. 1268 If none of the ETRs have requested proxy reply service, then the Map- 1269 Server re-encapsulates and forwards the resulting Encapsulated Map- 1270 Request to one of the registered ETRs. It does not otherwise alter 1271 the Map-Request, so any Map-Reply sent by the ETR is returned to the 1272 RLOC in the Map-Request, not to the Map-Server. Unless also acting 1273 as a Map-Resolver, a Map-Server should never receive Map-Replies; any 1274 such messages should be discarded without response, perhaps 1275 accompanied by the logging of a diagnostic message if the rate of 1276 Map-Replies is suggestive of malicious traffic. 1278 5.4. Map-Resolver Processing 1280 Upon receipt of an Encapsulated Map-Request, a Map-Resolver 1281 decapsulates the enclosed message and then searches for the requested 1282 EID in its local database of mapping entries (statically configured 1283 or learned from associated ETRs if the Map-Resolver is also a Map- 1284 Server offering proxy reply service). If it finds a matching entry, 1285 it returns a LISP Map-Reply with the known mapping. 1287 If the Map-Resolver does not have the mapping entry and if it can 1288 determine that the EID is not in the mapping database (for example, 1289 if LISP+ALT is used, the Map-Resolver will have an ALT forwarding 1290 table that covers the full EID space), it immediately returns a 1291 negative LISP Map-Reply, with action code "Natively-Forward" and a 1292 15-minute TTL. To minimize the number of negative cache entries 1293 needed by an ITR, the Map-Resolver should return the least-specific 1294 prefix that both matches the original query and does not match any 1295 EID-Prefix known to exist in the LISP-capable infrastructure. 1297 If the Map-Resolver does not have sufficient information to know 1298 whether the EID exists, it needs to forward the Map-Request to 1299 another device that has more information about the EID being 1300 requested. To do this, it forwards the unencapsulated Map-Request, 1301 with the original ITR RLOC as the source, to the mapping database 1302 system. Using LISP+ALT, the Map-Resolver is connected to the ALT 1303 network and sends the Map-Request to the next ALT hop learned from 1304 its ALT BGP neighbors. The Map-Resolver does not send any response 1305 to the ITR; since the source RLOC is that of the ITR, the ETR or Map- 1306 Server that receives the Map-Request over the ALT and responds will 1307 do so directly to the ITR. 1309 5.4.1. Anycast Map-Resolver Operation 1311 A Map-Resolver can be set up to use "anycast", where the same address 1312 is assigned to multiple Map-Resolvers and is propagated through IGP 1313 routing, to facilitate the use of a topologically close Map-Resolver 1314 by each ITR. 1316 Note that Map-Server associations with ETRs should not use anycast 1317 addresses, as registrations need to be established between an ETR and 1318 a specific set of Map-Servers, each identified by a specific 1319 registration association. 1321 6. Security Considerations 1323 The 2-way LISP header nonce exchange documented in 1324 [I-D.ietf-lisp-rfc6830bis] can be used to avoid ITR spoofing attacks. 1326 To publish an authoritative EID-to-RLOC mapping with a Map-Server, an 1327 ETR includes authentication data that is a hash of the message using 1328 a pair-wise shared key. An implementation must support use of HMAC- 1329 SHA-1-96 [RFC2104] and should support use of HMAC-SHA-256-128 1330 [RFC6234] (SHA-256 truncated to 128 bits). 1332 As noted in Section 5.2, a Map-Server should verify that all EID- 1333 Prefixes registered by an ETR match the configuration stored on the 1334 Map-Server. 1336 The currently defined authentication mechanism for Map-Register 1337 messages does not provide protection against "replay" attacks by a 1338 "man-in-the-middle". Additional work is needed in this area. 1340 [I-D.ietf-lisp-sec] defines a proposed mechanism for providing origin 1341 authentication, integrity, anti-replay protection, and prevention of 1342 man-in-the-middle and "overclaiming" attacks on the Map-Request/Map- 1343 Reply exchange. Work is ongoing on this and other proposals for 1344 resolving these open security issues. 1346 While beyond the scope of securing an individual Map-Server or Map- 1347 Resolver, it should be noted that a BGP-based LISP+ALT network (if 1348 ALT is used as the mapping database infrastructure) can take 1349 advantage of standards work on adding security to BGP. 1351 A complete LISP threat analysis has been published in [RFC7835]. 1352 Please refer to it for more security related details. 1354 7. IANA Considerations 1356 This section provides guidance to the Internet Assigned Numbers 1357 Authority (IANA) regarding registration of values related to this 1358 LISP control-plane specification, in accordance with BCP 26 1359 [RFC5226]. 1361 There are three namespaces (listed in the sub-sections below) in LISP 1362 that have been registered. 1364 o LISP IANA registry allocations should not be made for purposes 1365 unrelated to LISP routing or transport protocols. 1367 o The following policies are used here with the meanings defined in 1368 BCP 26: "Specification Required", "IETF Review", "Experimental 1369 Use", and "First Come First Served". 1371 7.1. LISP Packet Type Codes 1373 It is being requested that the IANA be authoritative for LISP Packet 1374 Type definitions and that it refers to this document as well as 1375 [RFC8113] as references. 1377 Based on deployment experience of [RFC6830], the Map-Notify-Ack 1378 message, message type 5, was added to this document. This document 1379 requests IANA to add it to the LISP Packet Type Registry. 1381 7.2. LISP ACT and Flag Fields 1383 New ACT values can be allocated through IETF review or IESG approval. 1384 Four values have already been allocated by [RFC6830]. This 1385 specification changes the name of ACT type 3 value from "Drop" to 1386 "Drop/No-Reason" as well as adding two new ACT values, the "Drop/ 1387 Policy-Denied" (type 4) and "Drop/Authentication-Failure" (type 5). 1389 In addition, LISP has a number of flag fields and reserved fields, 1390 such as the LISP header flags field [I-D.ietf-lisp-rfc6830bis]. New 1391 bits for flags in these fields can be implemented after IETF review 1392 or IESG approval, but these need not be managed by IANA. 1394 7.3. LISP Address Type Codes 1396 LISP Canonical Address Format (LCAF) [RFC8060] is an 8-bit field that 1397 defines LISP-specific encodings for AFI value 16387. LCAF encodings 1398 are used for specific use-cases where different address types for 1399 EID-records and RLOC-records are required. 1401 The IANA registry "LISP Canonical Address Format (LCAF) Types" is 1402 used for LCAF types, the registry for LCAF types use the 1403 Specification Required policy [RFC5226]. Initial values for the 1404 registry as well as further information can be found in [RFC8060]. 1406 Therefore, there is no longer a need for the "LISP Address Type 1407 Codes" registry requested by [RFC6830]. This document requests to 1408 remove it. 1410 7.4. LISP Algorithm ID Numbers 1412 In [RFC6830], a request for a "LISP Key ID Numbers" registry was 1413 submitted. This document renames the registry to "LISP Algorithm ID 1414 Numbers" and requests the IANA to make the name change. 1416 The following Algorithm ID values are defined by this specification 1417 as used in any packet type that references a 'Algorithm ID' field: 1419 Name Number Defined in 1420 ----------------------------------------------- 1421 None 0 n/a 1422 HMAC-SHA-1-96 1 [RFC2404] 1423 HMAC-SHA-256-128 2 [RFC4868] 1425 Number values are in the range of 0 to 255. The allocation of values 1426 is on a first come first served basis. 1428 8. References 1430 8.1. Normative References 1432 [RFC1035] Mockapetris, P., "Domain names - implementation and 1433 specification", STD 13, RFC 1035, DOI 10.17487/RFC1035, 1434 November 1987, . 1436 [RFC2104] Krawczyk, H., Bellare, M., and R. Canetti, "HMAC: Keyed- 1437 Hashing for Message Authentication", RFC 2104, 1438 DOI 10.17487/RFC2104, February 1997, 1439 . 1441 [RFC2404] Madson, C. and R. Glenn, "The Use of HMAC-SHA-1-96 within 1442 ESP and AH", RFC 2404, DOI 10.17487/RFC2404, November 1443 1998, . 1445 [RFC4086] Eastlake 3rd, D., Schiller, J., and S. Crocker, 1446 "Randomness Requirements for Security", BCP 106, RFC 4086, 1447 DOI 10.17487/RFC4086, June 2005, 1448 . 1450 [RFC4107] Bellovin, S. and R. Housley, "Guidelines for Cryptographic 1451 Key Management", BCP 107, RFC 4107, DOI 10.17487/RFC4107, 1452 June 2005, . 1454 [RFC4868] Kelly, S. and S. Frankel, "Using HMAC-SHA-256, HMAC-SHA- 1455 384, and HMAC-SHA-512 with IPsec", RFC 4868, 1456 DOI 10.17487/RFC4868, May 2007, 1457 . 1459 [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an 1460 IANA Considerations Section in RFCs", RFC 5226, 1461 DOI 10.17487/RFC5226, May 2008, 1462 . 1464 [RFC6234] Eastlake 3rd, D. and T. Hansen, "US Secure Hash Algorithms 1465 (SHA and SHA-based HMAC and HKDF)", RFC 6234, 1466 DOI 10.17487/RFC6234, May 2011, 1467 . 1469 [RFC6830] Farinacci, D., Fuller, V., Meyer, D., and D. Lewis, "The 1470 Locator/ID Separation Protocol (LISP)", RFC 6830, 1471 DOI 10.17487/RFC6830, January 2013, 1472 . 1474 [RFC6831] Farinacci, D., Meyer, D., Zwiebel, J., and S. Venaas, "The 1475 Locator/ID Separation Protocol (LISP) for Multicast 1476 Environments", RFC 6831, DOI 10.17487/RFC6831, January 1477 2013, . 1479 [RFC6836] Fuller, V., Farinacci, D., Meyer, D., and D. Lewis, 1480 "Locator/ID Separation Protocol Alternative Logical 1481 Topology (LISP+ALT)", RFC 6836, DOI 10.17487/RFC6836, 1482 January 2013, . 1484 [RFC6837] Lear, E., "NERD: A Not-so-novel Endpoint ID (EID) to 1485 Routing Locator (RLOC) Database", RFC 6837, 1486 DOI 10.17487/RFC6837, January 2013, 1487 . 1489 [RFC7348] Mahalingam, M., Dutt, D., Duda, K., Agarwal, P., Kreeger, 1490 L., Sridhar, T., Bursell, M., and C. Wright, "Virtual 1491 eXtensible Local Area Network (VXLAN): A Framework for 1492 Overlaying Virtualized Layer 2 Networks over Layer 3 1493 Networks", RFC 7348, DOI 10.17487/RFC7348, August 2014, 1494 . 1496 [RFC7835] Saucez, D., Iannone, L., and O. Bonaventure, "Locator/ID 1497 Separation Protocol (LISP) Threat Analysis", RFC 7835, 1498 DOI 10.17487/RFC7835, April 2016, 1499 . 1501 [RFC8060] Farinacci, D., Meyer, D., and J. Snijders, "LISP Canonical 1502 Address Format (LCAF)", RFC 8060, DOI 10.17487/RFC8060, 1503 February 2017, . 1505 [RFC8111] Fuller, V., Lewis, D., Ermagan, V., Jain, A., and A. 1506 Smirnov, "Locator/ID Separation Protocol Delegated 1507 Database Tree (LISP-DDT)", RFC 8111, DOI 10.17487/RFC8111, 1508 May 2017, . 1510 [RFC8113] Boucadair, M. and C. Jacquenet, "Locator/ID Separation 1511 Protocol (LISP): Shared Extension Message & IANA Registry 1512 for Packet Type Allocations", RFC 8113, 1513 DOI 10.17487/RFC8113, March 2017, 1514 . 1516 8.2. Informative References 1518 [AFI] IANA, "Address Family Identifier (AFIs)", ADDRESS FAMILY 1519 NUMBERS http://www.iana.org/assignments/address-family- 1520 numbers/address-family-numbers.xhtml?, Febuary 2007. 1522 [I-D.ermagan-lisp-nat-traversal] 1523 Ermagan, V., Farinacci, D., Lewis, D., Skriver, J., Maino, 1524 F., and C. White, "NAT traversal for LISP", draft-ermagan- 1525 lisp-nat-traversal-13 (work in progress), September 2017. 1527 [I-D.ietf-lisp-eid-mobility] 1528 Portoles-Comeras, M., Ashtaputre, V., Moreno, V., Maino, 1529 F., and D. Farinacci, "LISP L2/L3 EID Mobility Using a 1530 Unified Control Plane", draft-ietf-lisp-eid-mobility-00 1531 (work in progress), May 2017. 1533 [I-D.ietf-lisp-introduction] 1534 Cabellos-Aparicio, A. and D. Saucez, "An Architectural 1535 Introduction to the Locator/ID Separation Protocol 1536 (LISP)", draft-ietf-lisp-introduction-13 (work in 1537 progress), April 2015. 1539 [I-D.ietf-lisp-mn] 1540 Farinacci, D., Lewis, D., Meyer, D., and C. White, "LISP 1541 Mobile Node", draft-ietf-lisp-mn-00 (work in progress), 1542 April 2017. 1544 [I-D.ietf-lisp-rfc6830bis] 1545 Farinacci, D., Fuller, V., Meyer, D., Lewis, D., and A. 1546 Cabellos-Aparicio, "The Locator/ID Separation Protocol 1547 (LISP)", draft-ietf-lisp-rfc6830bis-05 (work in progress), 1548 August 2017. 1550 [I-D.ietf-lisp-sec] 1551 Maino, F., Ermagan, V., Cabellos-Aparicio, A., and D. 1552 Saucez, "LISP-Security (LISP-SEC)", draft-ietf-lisp-sec-13 1553 (work in progress), September 2017. 1555 [I-D.ietf-lisp-signal-free-multicast] 1556 Moreno, V. and D. Farinacci, "Signal-Free LISP Multicast", 1557 draft-ietf-lisp-signal-free-multicast-06 (work in 1558 progress), August 2017. 1560 [I-D.lewis-lisp-gpe] 1561 Lewis, D., Agarwal, P., Kreeger, L., Maino, F., Quinn, P., 1562 Smith, M., and N. Yadav, "LISP Generic Protocol 1563 Extension", draft-lewis-lisp-gpe-02 (work in progress), 1564 July 2014. 1566 [I-D.quinn-vxlan-gpe] 1567 Quinn, P., Manur, R., Kreeger, L., Lewis, D., Maino, F., 1568 Smith, M., Agarwal, P., Yong, L., Xu, X., Elzur, U., Garg, 1569 P., and D. Melman, "Generic Protocol Extension for VXLAN", 1570 draft-quinn-vxlan-gpe-04 (work in progress), February 1571 2015. 1573 [I-D.rodrigueznatal-lisp-pubsub] 1574 Rodriguez-Natal, A., Ermagan, V., Leong, J., Maino, F., 1575 Cabellos-Aparicio, A., Barkai, S., and D. Farinacci, 1576 "Publish-Subscribe mechanism for LISP", draft- 1577 rodrigueznatal-lisp-pubsub-00 (work in progress), August 1578 2017. 1580 [LISP-CONS] 1581 Brim, S., Chiappa, N., Farinacci, D., Fuller, V., Lewis, 1582 D., and D. Meyer, "LISP-CONS: A Content distribution 1583 Overlay Network Service for LISP", Work in Progress, April 1584 2008. 1586 Appendix A. Acknowledgments 1588 The authors would like to thank Greg Schudel, Darrel Lewis, John 1589 Zwiebel, Andrew Partan, Dave Meyer, Isidor Kouvelas, Jesper Skriver, 1590 Fabio Maino, and members of the lisp@ietf.org mailing list for their 1591 feedback and helpful suggestions. 1593 Special thanks are due to Noel Chiappa for his extensive work on 1594 caching with LISP-CONS, some of which may be used by Map-Resolvers. 1596 Appendix B. Document Change Log 1598 [RFC Editor: Please delete this section on publication as RFC.] 1600 B.1. Changes to draft-ietf-lisp-rfc6833bis-06 1602 o Posted October 2017. 1604 o Spec the I-bit to include the xTR-ID in a Map-Request message to 1605 be consistent with the Map-Register message and to anticipate the 1606 introduction of pubsub functionality to allow Map-Requests to 1607 subscribe to RLOC-set changes. 1609 o Updated references for individual submissions that became working 1610 group documents. 1612 o Updated references for working group documents that became RFCs. 1614 B.2. Changes to draft-ietf-lisp-rfc6833bis-05 1616 o Posted May 2017. 1618 o Update IANA Considerations section based on new requests from this 1619 document and changes from what was requested in [RFC6830]. 1621 B.3. Changes to draft-ietf-lisp-rfc6833bis-04 1623 o Posted May 2017. 1625 o Clarify how the Key-ID field is used in Map-Register and Map- 1626 Notify messages. Break the 16-bit field into a 8-bit Key-ID field 1627 and a 8-bit Algorithm-ID field. 1629 o Move the control-plane codepoints from the IANA Considerations 1630 section of RFC6830bis to the IANA Considerations section of this 1631 document. 1633 o In the "LISP Control Packet Type Allocations" section, indicate 1634 how message Types are IANA allocated and how experimental RFC8113 1635 sub-types should be requested. 1637 B.4. Changes to draft-ietf-lisp-rfc6833bis-03 1639 o Posted April 2017. 1641 o Add types 9-14 and specify they are not assigned. 1643 o Add the "LISP Shared Extension Message" type and point to RFC8113. 1645 B.5. Changes to draft-ietf-lisp-rfc6833bis-02 1647 o Posted April 2017. 1649 o Clarify that the LISP control-plane document defines how the LISP 1650 data-plane uses Map-Requests with either the SMR-bit set or the 1651 P-bit set supporting mapping updates and RLOC-probing. Indicating 1652 that other data-planes can use the same mechanisms or their own 1653 defined mechanisms to achieve the same functionality. 1655 B.6. Changes to draft-ietf-lisp-rfc6833bis-01 1657 o Posted March 2017. 1659 o Include references to new RFCs published. 1661 o Remove references to self. 1663 o Change references from RFC6830 to RFC6830bis. 1665 o Add two new action/reasons to a Map-Reply has posted to the LISP 1666 WG mailing list. 1668 o In intro section, add refernece to I-D.ietf-lisp-introduction. 1670 o Removed Open Issues section and references to "experimental". 1672 B.7. Changes to draft-ietf-lisp-rfc6833bis-00 1674 o Posted December 2016. 1676 o Created working group document from draft-farinacci-lisp 1677 -rfc6833-00 individual submission. No other changes made. 1679 B.8. Changes to draft-farinacci-lisp-rfc6833bis-00 1681 o Posted November 2016. 1683 o This is the initial draft to turn RFC 6833 into RFC 6833bis. 1685 o The document name has changed from the "Locator/ID Separation 1686 Protocol (LISP) Map-Server Interface" to the "Locator/ID 1687 Separation Protocol (LISP) Control-Plane". 1689 o The fundamental change was to move the control-plane messages from 1690 RFC 6830 to this document in an effort so any IETF developed or 1691 industry created data-plane could use the LISP mapping system and 1692 control-plane. 1694 o Update control-plane messages to incorporate what has been 1695 implemented in products during the early phase of LISP development 1696 but wasn't able to make it into RFC6830 and RFC6833 to make the 1697 Experimental RFC deadline. 1699 o Indicate there may be nodes in the mapping system that are not MRs 1700 or MSs, that is a ALT-node or a DDT-node. 1702 o Include LISP-DDT in Map-Resolver section and explain how they 1703 maintain a referral-cache. 1705 o Removed open issue about additional state in Map-Servers. With 1706 [RFC8111], Map-Servers have the same registration state and can 1707 give Map-Resolvers complete information in ms-ack Map-Referral 1708 messages. 1710 o Make reference to the LISP Threats Analysis RFC [RFC7835]. 1712 Authors' Addresses 1714 Vince Fuller 1715 Cisco Systems 1717 EMail: vaf@vaf.net 1719 Dino Farinacci 1720 Cisco Systems 1722 EMail: farinacci@gmail.com 1723 Albert Cabellos 1724 UPC/BarcelonaTech 1725 Campus Nord, C. Jordi Girona 1-3 1726 Barcelona, Catalunya 1727 Spain 1729 EMail: acabello@ac.upc.edu