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Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year == Line 1850 has weird spacing: '...-Denied entry...' == Line 1855 has weird spacing: '...Failure entr...' == Using lowercase 'not' together with uppercase 'MUST', 'SHALL', 'SHOULD', or 'RECOMMENDED' is not an accepted usage according to RFC 2119. Please use uppercase 'NOT' together with RFC 2119 keywords (if that is what you mean). Found 'MUST not' in this paragraph: P: This is the probe-bit, which indicates that a Map-Request SHOULD be treated as a Locator reachability probe. The receiver SHOULD respond with a Map-Reply with the probe-bit set, indicating that the Map-Reply is a Locator reachability probe reply, with the nonce copied from the Map-Request. See RLOC-Probing Section 7.1 for more details. This RLOC-probe Map-Request MUST not be sent to the mapping system. If a Map-Resolver or Map-Server receives a Map-Request with the probe-bit set, it MUST drop the message. -- The document date (December 10, 2018) is 1963 days in the past. Is this intentional? Checking references for intended status: Proposed Standard ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) == Unused Reference: 'RFC6071' is defined on line 2071, but no explicit reference was found in the text == Outdated reference: A later version (-14) exists of draft-ietf-lisp-6834bis-02 == Outdated reference: A later version (-38) exists of draft-ietf-lisp-rfc6830bis-26 == Outdated reference: A later version (-29) exists of draft-ietf-lisp-sec-17 ** Downref: Normative reference to an Informational RFC: RFC 4984 ** Obsolete normative reference: RFC 5226 (Obsoleted by RFC 8126) ** Downref: Normative reference to an Informational RFC: RFC 6071 ** Obsolete normative reference: RFC 6347 (Obsoleted by RFC 9147) == Outdated reference: A later version (-12) exists of draft-ietf-lisp-ecdsa-auth-00 == Outdated reference: A later version (-16) exists of draft-ietf-lisp-eid-anonymity-04 == Outdated reference: A later version (-13) exists of draft-ietf-lisp-eid-mobility-03 == Outdated reference: A later version (-19) exists of draft-ietf-lisp-gpe-06 == Outdated reference: A later version (-15) exists of draft-ietf-lisp-introduction-13 == Outdated reference: A later version (-15) exists of draft-ietf-lisp-mn-04 == Outdated reference: A later version (-15) exists of draft-ietf-lisp-pubsub-02 == Outdated reference: A later version (-13) exists of draft-ietf-nvo3-vxlan-gpe-06 -- Obsolete informational reference (is this intentional?): RFC 6830 (Obsoleted by RFC 9300, RFC 9301) -- Obsolete informational reference (is this intentional?): RFC 8113 (Obsoleted by RFC 9304) Summary: 4 errors (**), 0 flaws (~~), 16 warnings (==), 5 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Network Working Group V. Fuller 3 Internet-Draft D. Farinacci 4 Obsoletes: 6833 (if approved) Cisco Systems 5 Intended status: Standards Track A. Cabellos (Ed.) 6 Expires: June 13, 2019 UPC/BarcelonaTech 7 December 10, 2018 9 Locator/ID Separation Protocol (LISP) Control-Plane 10 draft-ietf-lisp-rfc6833bis-23 12 Abstract 14 This document describes the Control-Plane and Mapping Service for the 15 Locator/ID Separation Protocol (LISP), implemented by two new types 16 of LISP-speaking devices -- the LISP Map-Resolver and LISP Map-Server 17 -- that provides a simplified "front end" for one or more Endpoint ID 18 to Routing Locator mapping databases. 20 By using this Control-Plane service interface and communicating with 21 Map-Resolvers and Map-Servers, LISP Ingress Tunnel Routers (ITRs) and 22 Egress Tunnel Routers (ETRs) are not dependent on the details of 23 mapping database systems, which facilitates modularity with different 24 database designs. Since these devices implement the "edge" of the 25 LISP Control-Plane infrastructure, connecting EID addressable nodes 26 of a LISP site, their implementation and operational complexity 27 reduces the overall cost and effort of deploying LISP. 29 This document obsoletes RFC 6830 and 6833. 31 Status of This Memo 33 This Internet-Draft is submitted in full conformance with the 34 provisions of BCP 78 and BCP 79. 36 Internet-Drafts are working documents of the Internet Engineering 37 Task Force (IETF). Note that other groups may also distribute 38 working documents as Internet-Drafts. The list of current Internet- 39 Drafts is at https://datatracker.ietf.org/drafts/current/. 41 Internet-Drafts are draft documents valid for a maximum of six months 42 and may be updated, replaced, or obsoleted by other documents at any 43 time. It is inappropriate to use Internet-Drafts as reference 44 material or to cite them other than as "work in progress." 46 This Internet-Draft will expire on June 13, 2019. 48 Copyright Notice 50 Copyright (c) 2018 IETF Trust and the persons identified as the 51 document authors. All rights reserved. 53 This document is subject to BCP 78 and the IETF Trust's Legal 54 Provisions Relating to IETF Documents 55 (https://trustee.ietf.org/license-info) in effect on the date of 56 publication of this document. Please review these documents 57 carefully, as they describe your rights and restrictions with respect 58 to this document. Code Components extracted from this document must 59 include Simplified BSD License text as described in Section 4.e of 60 the Trust Legal Provisions and are provided without warranty as 61 described in the Simplified BSD License. 63 Table of Contents 65 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 66 1.1. Scope of Applicability . . . . . . . . . . . . . . . . . 4 67 2. Requirements Notation . . . . . . . . . . . . . . . . . . . . 5 68 3. Definition of Terms . . . . . . . . . . . . . . . . . . . . . 5 69 4. Basic Overview . . . . . . . . . . . . . . . . . . . . . . . 6 70 5. LISP IPv4 and IPv6 Control-Plane Packet Formats . . . . . . . 8 71 5.1. LISP Control Packet Type Allocations . . . . . . . . . . 11 72 5.2. Map-Request Message Format . . . . . . . . . . . . . . . 12 73 5.3. EID-to-RLOC UDP Map-Request Message . . . . . . . . . . . 15 74 5.4. Map-Reply Message Format . . . . . . . . . . . . . . . . 17 75 5.5. EID-to-RLOC UDP Map-Reply Message . . . . . . . . . . . . 21 76 5.6. Map-Register Message Format . . . . . . . . . . . . . . . 24 77 5.7. Map-Notify/Map-Notify-Ack Message Format . . . . . . . . 28 78 5.8. Encapsulated Control Message Format . . . . . . . . . . . 30 79 6. Changing the Contents of EID-to-RLOC Mappings . . . . . . . . 32 80 6.1. Solicit-Map-Request (SMR) . . . . . . . . . . . . . . . . 32 81 7. Routing Locator Reachability . . . . . . . . . . . . . . . . 33 82 7.1. RLOC-Probing Algorithm . . . . . . . . . . . . . . . . . 35 83 8. Interactions with Other LISP Components . . . . . . . . . . . 36 84 8.1. ITR EID-to-RLOC Mapping Resolution . . . . . . . . . . . 36 85 8.2. EID-Prefix Configuration and ETR Registration . . . . . . 37 86 8.3. Map-Server Processing . . . . . . . . . . . . . . . . . . 39 87 8.4. Map-Resolver Processing . . . . . . . . . . . . . . . . . 40 88 8.4.1. Anycast Operation . . . . . . . . . . . . . . . . . . 40 89 9. Security Considerations . . . . . . . . . . . . . . . . . . . 41 90 10. Privacy Considerations . . . . . . . . . . . . . . . . . . . 42 91 11. Changes since RFC 6833 . . . . . . . . . . . . . . . . . . . 43 92 12. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 44 93 12.1. LISP UDP Port Numbers . . . . . . . . . . . . . . . . . 44 94 12.2. LISP Packet Type Codes . . . . . . . . . . . . . . . . . 44 95 12.3. LISP ACT and Flag Fields . . . . . . . . . . . . . . . . 44 96 12.4. LISP Address Type Codes . . . . . . . . . . . . . . . . 45 97 12.5. LISP Algorithm ID Numbers . . . . . . . . . . . . . . . 45 98 12.6. LISP Bit Flags . . . . . . . . . . . . . . . . . . . . . 46 99 13. References . . . . . . . . . . . . . . . . . . . . . . . . . 49 100 13.1. Normative References . . . . . . . . . . . . . . . . . . 49 101 13.2. Informative References . . . . . . . . . . . . . . . . . 50 102 Appendix A. Acknowledgments . . . . . . . . . . . . . . . . . . 55 103 Appendix B. Document Change Log . . . . . . . . . . . . . . . . 55 104 B.1. Changes to draft-ietf-lisp-rfc6833bis-23 . . . . . . . . 55 105 B.2. Changes to draft-ietf-lisp-rfc6833bis-22 . . . . . . . . 55 106 B.3. Changes to draft-ietf-lisp-rfc6833bis-21 . . . . . . . . 56 107 B.4. Changes to draft-ietf-lisp-rfc6833bis-20 . . . . . . . . 56 108 B.5. Changes to draft-ietf-lisp-rfc6833bis-19 . . . . . . . . 56 109 B.6. Changes to draft-ietf-lisp-rfc6833bis-18 . . . . . . . . 56 110 B.7. Changes to draft-ietf-lisp-rfc6833bis-17 . . . . . . . . 56 111 B.8. Changes to draft-ietf-lisp-rfc6833bis-16 . . . . . . . . 57 112 B.9. Changes to draft-ietf-lisp-rfc6833bis-15 . . . . . . . . 57 113 B.10. Changes to draft-ietf-lisp-rfc6833bis-14 . . . . . . . . 57 114 B.11. Changes to draft-ietf-lisp-rfc6833bis-13 . . . . . . . . 57 115 B.12. Changes to draft-ietf-lisp-rfc6833bis-12 . . . . . . . . 57 116 B.13. Changes to draft-ietf-lisp-rfc6833bis-11 . . . . . . . . 57 117 B.14. Changes to draft-ietf-lisp-rfc6833bis-10 . . . . . . . . 58 118 B.15. Changes to draft-ietf-lisp-rfc6833bis-09 . . . . . . . . 58 119 B.16. Changes to draft-ietf-lisp-rfc6833bis-08 . . . . . . . . 58 120 B.17. Changes to draft-ietf-lisp-rfc6833bis-07 . . . . . . . . 58 121 B.18. Changes to draft-ietf-lisp-rfc6833bis-06 . . . . . . . . 59 122 B.19. Changes to draft-ietf-lisp-rfc6833bis-05 . . . . . . . . 59 123 B.20. Changes to draft-ietf-lisp-rfc6833bis-04 . . . . . . . . 59 124 B.21. Changes to draft-ietf-lisp-rfc6833bis-03 . . . . . . . . 60 125 B.22. Changes to draft-ietf-lisp-rfc6833bis-02 . . . . . . . . 60 126 B.23. Changes to draft-ietf-lisp-rfc6833bis-01 . . . . . . . . 60 127 B.24. Changes to draft-ietf-lisp-rfc6833bis-00 . . . . . . . . 60 128 B.25. Changes to draft-farinacci-lisp-rfc6833bis-00 . . . . . . 60 129 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 61 131 1. Introduction 133 The Locator/ID Separation Protocol [I-D.ietf-lisp-rfc6830bis] (see 134 also [I-D.ietf-lisp-introduction]) specifies an architecture and 135 mechanism for dynamic tunneling by logically separating the addresses 136 currently used by IP in two separate name spaces: Endpoint IDs 137 (EIDs), used within sites; and Routing Locators (RLOCs), used on the 138 transit networks that make up the Internet infrastructure. To 139 achieve this separation, LISP defines protocol mechanisms for mapping 140 from EIDs to RLOCs. In addition, LISP assumes the existence of a 141 database to store and propagate those mappings across mapping system 142 nodes. Several such databases have been proposed; among them are the 143 Content distribution Overlay Network Service for LISP-NERD (a Not-so- 144 novel EID-to-RLOC Database) [RFC6837], LISP Alternative Logical 145 Topology (LISP-ALT) [RFC6836], and LISP Delegated Database Tree 146 (LISP-DDT) [RFC8111]. 148 The LISP Mapping Service defines two new types of LISP-speaking 149 devices: the Map-Resolver, which accepts Map-Requests from an Ingress 150 Tunnel Router (ITR) and "resolves" the EID-to-RLOC mapping using a 151 mapping database; and the Map-Server, which learns authoritative EID- 152 to-RLOC mappings from an Egress Tunnel Router (ETR) and publishes 153 them in a database. 155 This LISP Control-Plane Mapping Service can be used by many different 156 encapsulation-based or translation-based Data-Planes which include 157 but are not limited to the ones defined in LISP RFC 6830bis 158 [I-D.ietf-lisp-rfc6830bis], LISP-GPE [I-D.ietf-lisp-gpe], VXLAN 159 [RFC7348], VXLAN-GPE [I-D.ietf-nvo3-vxlan-gpe], GRE [RFC2890], GTP 160 [GTP-3GPP], ILA [I-D.herbert-intarea-ila], and Segment Routing (SRv6) 161 [RFC8402]. 163 Conceptually, LISP Map-Servers share some of the same basic 164 configuration and maintenance properties as Domain Name System (DNS) 165 [RFC1035] servers; likewise, Map-Resolvers are conceptually similar 166 to DNS caching resolvers. With this in mind, this specification 167 borrows familiar terminology (resolver and server) from the DNS 168 specifications. 170 Note this document doesn't assume any particular database mapping 171 infrastructure to illustrate certain aspects of Map-Server and Map- 172 Resolver operation. The Mapping Service interface can (and likely 173 will) be used by ITRs and ETRs to access other mapping database 174 systems as the LISP infrastructure evolves. 176 LISP is not intended to address problems of connectivity and scaling 177 on behalf of arbitrary communicating parties. Relevant situations 178 are described in the scoping section of the introduction to 179 [I-D.ietf-lisp-rfc6830bis]. 181 This document obsoletes RFC 6830 and 6833. 183 1.1. Scope of Applicability 185 LISP was originally developed to address the Internet-wide route 186 scaling problem [RFC4984].. While there are a number of approaches 187 of interest for that problem, as LISP as been developed and refined, 188 a large number of other LISP uses have been found and are being used. 189 As such, the design and development of LISP has changed so as to 190 focus on these use cases. The common property of these uses is a 191 large set of cooperating entities seeking to communicate over the 192 public Internet or other large underlay IP infrastructures, while 193 keeping the addressing and topology of the cooperating entities 194 separate from the underlay and Internet topology, routing, and 195 addressing. 197 2. Requirements Notation 199 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 200 "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and 201 "OPTIONAL" in this document are to be interpreted as described in BCP 202 14 [RFC2119] [RFC8174] when, and only when, they appear in all 203 capitals, as shown here. 205 3. Definition of Terms 207 Map-Server: A network infrastructure component that learns of EID- 208 Prefix mapping entries from an ETR, via the registration mechanism 209 described below, or some other authoritative source if one exists. 210 A Map-Server publishes these EID-Prefixes in a mapping database. 212 Map-Request: A LISP Map-Request is a Control-Plane message to query 213 the mapping system to resolve an EID. A LISP Map-Request can also 214 be sent to an RLOC to test for reachability and to exchange 215 security keys between an encapsulator and a decapsulator. This 216 type of Map-Request is also known as an RLOC-Probe Request. 218 Map-Reply: A LISP Map-Reply is a Control-Plane message returned in 219 response to a Map-Request sent to the mapping system when 220 resolving an EID. A LISP Map-Reply can also be returned by a 221 decapsulator in response to a Map-Request sent by an encapsulator 222 to test for reachability. This type of Map-Reply is known as a 223 RLOC-Probe Reply. 225 Encapsulated Map-Request: A LISP Map-Request carried within an 226 Encapsulated Control Message (ECM), which has an additional LISP 227 header prepended. Sent to UDP destination port 4342. The "outer" 228 addresses are routable IP addresses, also known as RLOCs. Used by 229 an ITR when sending to a Map-Resolver and by a Map-Server when 230 forwarding a Map-Request to an ETR. 232 Map-Resolver: A network infrastructure component that accepts LISP 233 Encapsulated (ECM) Map-Requests, typically from an ITR, and 234 determines whether or not the destination IP address is part of 235 the EID namespace; if it is not, a Negative Map-Reply is returned. 236 Otherwise, the Map-Resolver finds the appropriate EID-to-RLOC 237 mapping by consulting a mapping database system. 239 Negative Map-Reply: A LISP Map-Reply that contains an empty 240 Locator-Set. Returned in response to a Map-Request if the 241 destination EID is not registered in the mapping system, is policy 242 denied or fails authentication. 244 Map-Register message: A LISP message sent by an ETR to a Map-Server 245 to register its associated EID-Prefixes. In addition to the set 246 of EID-Prefixes to register, the message includes one or more 247 RLOCs to reach ETR(s). The Map-Server uses these RLOCs when 248 forwarding Map-Requests (re-formatted as Encapsulated Map- 249 Requests). An ETR MAY request that the Map-Server answer Map- 250 Requests on its behalf by setting the "proxy Map-Reply" flag 251 (P-bit) in the message. 253 Map-Notify message: A LISP message sent by a Map-Server to an ETR 254 to confirm that a Map-Register has been received and processed. 255 An ETR requests that a Map-Notify be returned by setting the 256 "want-map-notify" flag (M-bit) in the Map-Register message. 257 Unlike a Map-Reply, a Map-Notify uses UDP port 4342 for both 258 source and destination. Map-Notify messages are also sent to ITRs 259 by Map-Servers when there are RLOC-set changes. 261 For definitions of other terms, notably Ingress Tunnel Router (ITR), 262 Egress Tunnel Router (ETR), and Re-encapsulating Tunnel Router (RTR), 263 refer to the LISP Data-Plane specification 264 [I-D.ietf-lisp-rfc6830bis]. 266 4. Basic Overview 268 A Map-Server is a device that publishes EID-Prefixes in a LISP 269 mapping database on behalf of a set of ETRs. When it receives a Map 270 Request (typically from an ITR), it consults the mapping database to 271 find an ETR that can answer with the set of RLOCs for an EID-Prefix. 272 To publish its EID-Prefixes, an ETR periodically sends Map-Register 273 messages to the Map-Server. A Map-Register message contains a list 274 of EID-Prefixes plus a set of RLOCs that can be used to reach the 275 ETRs. 277 When LISP-ALT [RFC6836] is used as the mapping database, a Map-Server 278 connects to the ALT network and acts as a "last-hop" ALT-Router. 279 Intermediate ALT-Routers forward Map-Requests to the Map-Server that 280 advertises a particular EID-Prefix, and the Map-Server forwards them 281 to the owning ETR, which responds with Map-Reply messages. 283 When LISP-DDT [RFC8111] is used as the mapping database, a Map-Server 284 sends the final Map-Referral messages from the Delegated Database 285 Tree. 287 A Map-Resolver receives Encapsulated Map-Requests from its client 288 ITRs and uses a mapping database system to find the appropriate ETR 289 to answer those requests. On a LISP-ALT network, a Map-Resolver acts 290 as a "first-hop" ALT-Router. It has Generic Routing Encapsulation 291 (GRE) tunnels configured to other ALT-Routers and uses BGP to learn 292 paths to ETRs for different prefixes in the LISP-ALT database. The 293 Map-Resolver uses this path information to forward Map-Requests over 294 the ALT to the correct ETRs. On a LISP-DDT network [RFC8111], a Map- 295 Resolver maintains a referral-cache and acts as a "first-hop" DDT- 296 node. The Map-Resolver uses the referral information to forward Map- 297 Requests. 299 Note that while it is conceivable that a Map-Resolver could cache 300 responses to improve performance, issues surrounding cache management 301 will need to be resolved so that doing so will be reliable and 302 practical. As initially deployed, Map-Resolvers will operate only in 303 a non-caching mode, decapsulating and forwarding Encapsulated Map 304 Requests received from ITRs. Any specification of caching 305 functionality is out of scope for this document. 307 Note that a single device can implement the functions of both a Map- 308 Server and a Map-Resolver, and in many cases the functions will be 309 co-located in that way. Also, there can be ALT-only nodes and DDT- 310 only nodes, when LISP-ALT and LISP-DDT are used, respectively, to 311 connecting Map-Resolvers and Map-Servers together to make up the 312 Mapping System. 314 5. LISP IPv4 and IPv6 Control-Plane Packet Formats 316 The following UDP packet formats are used by the LISP control plane. 318 0 1 2 3 319 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 1 320 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 321 |Version| IHL |Type of Service| Total Length | 322 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 323 | Identification |Flags| Fragment Offset | 324 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 325 | Time to Live | Protocol = 17 | Header Checksum | 326 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 327 | Source Routing Locator | 328 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 329 | Destination Routing Locator | 330 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 331 / | Source Port | Dest Port | 332 UDP +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 333 \ | UDP Length | UDP Checksum | 334 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 335 | | 336 | LISP Message | 337 | | 338 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 340 IPv4 UDP LISP Control Message 342 0 1 2 3 343 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 1 344 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 345 |Version| Traffic Class | Flow Label | 346 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 347 | Payload Length | Next Header=17| Hop Limit | 348 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 349 | | 350 + + 351 | | 352 + Source Routing Locator + 353 | | 354 + + 355 | | 356 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 357 | | 358 + + 359 | | 360 + Destination Routing Locator + 361 | | 362 + + 363 | | 364 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 365 / | Source Port | Dest Port | 366 UDP +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 367 \ | UDP Length | UDP Checksum | 368 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 369 | | 370 | LISP Message | 371 | | 372 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 374 IPv6 UDP LISP Control Message 376 When a UDP Map-Request, Map-Register, or Map-Notify (when used as a 377 notification message) are sent, the UDP source port is chosen by the 378 sender and the destination UDP port number is set to 4342. When a 379 UDP Map-Reply, Map-Notify (when used as an acknowledgement to a Map- 380 Register), or Map-Notify-Ack are sent, the source UDP port number is 381 set to 4342 and the destination UDP port number is copied from the 382 source port of either the Map-Request or the invoking data packet. 383 Implementations MUST be prepared to accept packets when either the 384 source port or destination UDP port is set to 4342 due to NATs 385 changing port number values. 387 The 'UDP Length' field will reflect the length of the UDP header and 388 the LISP Message payload. Implementations should follow the 389 procedures from [RFC8085] to determine the maximum size used for any 390 LISP control message. 392 The UDP checksum is computed and set to non-zero for all messages 393 sent to or from port 4342. It MUST be checked on receipt, and if the 394 checksum fails, the control message MUST be dropped [RFC1071]. 396 The format of control messages includes the UDP header so the 397 checksum and length fields can be used to protect and delimit message 398 boundaries. 400 5.1. LISP Control Packet Type Allocations 402 This section defines the LISP control message formats and summarizes 403 for IANA the LISP Type codes assigned by this document. For 404 completeness, the summary below includes the LISP Shared Extension 405 Message assigned by [RFC8113]. Message type definitions are: 407 Reserved: 0 b'0000' 408 LISP Map-Request: 1 b'0001' 409 LISP Map-Reply: 2 b'0010' 410 LISP Map-Register: 3 b'0011' 411 LISP Map-Notify: 4 b'0100' 412 LISP Map-Notify-Ack: 5 b'0101' 413 LISP Map-Referral: 6 b'0110' 414 Not Assigned 7 b'0111' 415 LISP Encapsulated Control Message: 8 b'1000' 416 Not Assigned 9-14 b'1001'- b'1110' 417 LISP Shared Extension Message: 15 b'1111' [RFC8113] 419 Values in the "Not Assigned" range can be assigned according to 420 procedures in [RFC8126]. 422 Protocol designers experimenting with new message formats are 423 recommended to use the LISP Shared Extension Message Type described 424 in [RFC8113]. 426 All LISP Control-Plane messages use Address Family Identifiers (AFI) 427 [AFI] or LISP Canonical Address Format (LCAF) [RFC8060] formats to 428 encode either fixed or variable length addresses. This includes 429 explicit fields in each control message or part of EID-records or 430 RLOC-records in commonly formatted messages. 432 The LISP control-plane describes how other data-planes can encode 433 messages to support the Soliciting of Map-Requests as well as RLOC- 434 probing procedures. 436 5.2. Map-Request Message Format 438 0 1 2 3 439 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 1 440 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 441 |Type=1 |A|M|P|S|p|s|R|R| Rsvd |L|D| IRC | Record Count | 442 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 443 | Nonce . . . | 444 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 445 | . . . Nonce | 446 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 447 | Source-EID-AFI | Source EID Address ... | 448 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 449 | ITR-RLOC-AFI 1 | ITR-RLOC Address 1 ... | 450 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 451 | ... | 452 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 453 | ITR-RLOC-AFI n | ITR-RLOC Address n ... | 454 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 455 / | Reserved | EID mask-len | EID-Prefix-AFI | 456 Rec +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 457 \ | EID-Prefix ... | 458 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 459 | Map-Reply Record ... | 460 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 462 Packet field descriptions: 464 Type: 1 (Map-Request) 466 A: This is an authoritative bit, which is set to 0 for UDP-based Map- 467 Requests sent by an ITR. It is set to 1 when an ITR wants the 468 destination site to return the Map-Reply rather than the mapping 469 database system returning a Map-Reply. 471 M: This is the map-data-present bit. When set, it indicates that a 472 Map-Reply Record segment is included in the Map-Request. 474 P: This is the probe-bit, which indicates that a Map-Request SHOULD 475 be treated as a Locator reachability probe. The receiver SHOULD 476 respond with a Map-Reply with the probe-bit set, indicating that 477 the Map-Reply is a Locator reachability probe reply, with the 478 nonce copied from the Map-Request. See RLOC-Probing Section 7.1 479 for more details. This RLOC-probe Map-Request MUST not be sent to 480 the mapping system. If a Map-Resolver or Map-Server receives a 481 Map-Request with the probe-bit set, it MUST drop the message. 483 S: This is the Solicit-Map-Request (SMR) bit. See Solicit-Map- 484 Request (SMRs) Section 6.1 for details. 486 p: This is the PITR bit. This bit is set to 1 when a PITR sends a 487 Map-Request. 489 s: This is the SMR-invoked bit. This bit is set to 1 when an xTR is 490 sending a Map-Request in response to a received SMR-based Map- 491 Request. 493 R: This reserved and unassigned bit MUST be set to 0 on transmit and 494 MUST be ignored on receipt. 496 Rsvd: This field MUST be set to 0 on transmit and MUST be ignored on 497 receipt. 499 L: This is the local-xtr bit. It is used by an xTR in a LISP site to 500 tell other xTRs in the same site that it is part of the RLOC-set 501 for the LISP site. The L-bit is set to 1 when the RLOC is the 502 sender's IP address. 504 D: This is the dont-map-reply bit. It is used in the SMR procedure 505 described in Section 6.1. When an xTR sends an SMR Map-Request 506 message, it doesn't need a Map-Reply returned. When this bit is 507 set, the receiver of the Map-Request does not return a Map-Reply. 509 IRC: This 5-bit field is the ITR-RLOC Count, which encodes the 510 additional number of ('ITR-RLOC-AFI', 'ITR-RLOC Address') fields 511 present in this message. At least one (ITR-RLOC-AFI, ITR-RLOC- 512 Address) pair MUST be encoded. Multiple 'ITR-RLOC Address' fields 513 are used, so a Map-Replier can select which destination address to 514 use for a Map-Reply. The IRC value ranges from 0 to 31. For a 515 value of 0, there is 1 ITR-RLOC address encoded; for a value of 1, 516 there are 2 ITR-RLOC addresses encoded, and so on up to 31, which 517 encodes a total of 32 ITR-RLOC addresses. 519 Record Count: This is the number of records in this Map-Request 520 message. A record is comprised of the portion of the packet that 521 is labeled 'Rec' above and occurs the number of times equal to 522 Record Count. For this version of the protocol, a receiver MUST 523 accept and process Map-Requests that contain one or more records, 524 but a sender MUST only send Map-Requests containing one record. 525 Support for processing multiple EIDs in a single Map-Request 526 message will be specified in a future version of the protocol. 528 Nonce: This is an 8-octet random value created by the sender of the 529 Map-Request. This nonce will be returned in the Map-Reply. The 530 security of the LISP mapping protocol critically depends on the 531 strength of the nonce in the Map-Request message. The nonce MUST 532 be generated by a properly seeded pseudo-random (or strong random) 533 source. See [RFC4086] for advice on generating security-sensitive 534 random data. 536 Source-EID-AFI: This is the address family of the 'Source EID 537 Address' field. 539 Source EID Address: This is the EID of the source host that 540 originated the packet that caused the Map-Request. When Map- 541 Requests are used for refreshing a Map-Cache entry or for RLOC- 542 Probing, an AFI value 0 is used and this field is of zero length. 544 ITR-RLOC-AFI: This is the address family of the 'ITR-RLOC Address' 545 field that follows this field. 547 ITR-RLOC Address: This is used to give the ETR the option of 548 selecting the destination address from any address family for the 549 Map-Reply message. This address MUST be a routable RLOC address 550 of the sender of the Map-Request message. 552 EID mask-len: This is the mask length for the EID-Prefix. 554 EID-Prefix-AFI: This is the address family of the EID-Prefix 555 according to [AFI] and [RFC8060]. 557 EID-Prefix: This prefix address length is 4 octets for an IPv4 558 address family and 16 octets for an IPv6 address family when the 559 EID-Prefix-AFI is 1 or 2, respectively. For other AFIs [AFI], the 560 address length varies and for the LCAF AFI the format is defined 561 in [RFC8060]. When a Map-Request is sent by an ITR because a data 562 packet is received for a destination where there is no mapping 563 entry, the EID-Prefix is set to the destination IP address of the 564 data packet, and the 'EID mask-len' is set to 32 or 128 for IPv4 565 or IPv6, respectively. When an xTR wants to query a site about 566 the status of a mapping it already has cached, the EID-Prefix used 567 in the Map-Request has the same mask-length as the EID-Prefix 568 returned from the site when it sent a Map-Reply message. 570 Map-Reply Record: When the M-bit is set, this field is the size of a 571 single "Record" in the Map-Reply format. This Map-Reply record 572 contains the EID-to-RLOC mapping entry associated with the Source 573 EID. This allows the ETR that will receive this Map-Request to 574 cache the data if it chooses to do so. 576 5.3. EID-to-RLOC UDP Map-Request Message 578 A Map-Request is sent from an ITR when it needs a mapping for an EID, 579 wants to test an RLOC for reachability, or wants to refresh a mapping 580 before TTL expiration. For the initial case, the destination IP 581 address used for the Map-Request is the data packet's destination 582 address (i.e., the destination EID) that had a mapping cache lookup 583 failure. For the latter two cases, the destination IP address used 584 for the Map-Request is one of the RLOC addresses from the Locator-Set 585 of the Map-Cache entry. The source address is either an IPv4 or IPv6 586 RLOC address, depending on whether the Map-Request is using an IPv4 587 or IPv6 header, respectively. In all cases, the UDP source port 588 number for the Map-Request message is a 16-bit value selected by the 589 ITR/PITR, and the UDP destination port number is set to the well- 590 known destination port number 4342. A successful Map-Reply, which is 591 one that has a nonce that matches an outstanding Map-Request nonce, 592 will update the cached set of RLOCs associated with the EID-Prefix 593 range. 595 One or more Map-Request ('ITR-RLOC-AFI', 'ITR-RLOC-Address') fields 596 MUST be filled in by the ITR. The number of fields (minus 1) encoded 597 MUST be placed in the 'IRC' field. The ITR MAY include all locally 598 configured Locators in this list or just provide one locator address 599 from each address family it supports. If the ITR erroneously 600 provides no ITR-RLOC addresses, the Map-Replier MUST drop the Map- 601 Request. 603 Map-Requests can also be LISP encapsulated using UDP destination 604 port 4342 with a LISP Type value set to "Encapsulated Control 605 Message", when sent from an ITR to a Map-Resolver. Likewise, Map- 606 Requests are LISP encapsulated the same way from a Map-Server to an 607 ETR. Details on Encapsulated Map-Requests and Map-Resolvers can be 608 found in Section 5.8. 610 Map-Requests MUST be rate-limited. It is RECOMMENDED that a Map- 611 Request for the same EID-Prefix be sent no more than once per second. 612 However, recommendations from [RFC8085] SHOULD be considered. 614 An ITR that is configured with mapping database information (i.e., it 615 is also an ETR) MAY optionally include those mappings in a Map- 616 Request. When an ETR configured to accept and verify such 617 "piggybacked" mapping data receives such a Map-Request and it does 618 not have this mapping in the Map-Cache, it MAY originate a "verifying 619 Map-Request", addressed to the map-requesting ITR and the ETR MAY add 620 a Map-Cache entry. If the ETR (when it is an xTR co-located as an 621 ITR) has a Map-Cache entry that matches the "piggybacked" EID and the 622 RLOC is in the Locator-Set for the entry, then it MAY send the 623 "verifying Map-Request" directly to the originating Map-Request 624 source. If the RLOC is not in the Locator-Set, then the ETR MUST 625 send the "verifying Map-Request" to the "piggybacked" EID. Doing 626 this forces the "verifying Map-Request" to go through the mapping 627 database system to reach the authoritative source of information 628 about that EID, guarding against RLOC-spoofing in the "piggybacked" 629 mapping data. 631 5.4. Map-Reply Message Format 633 0 1 2 3 634 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 1 635 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 636 |Type=2 |P|E|S| Reserved | Record Count | 637 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 638 | Nonce . . . | 639 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 640 | . . . Nonce | 641 +-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 642 | | Record TTL | 643 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 644 R | Locator Count | EID mask-len | ACT |A| Reserved | 645 e +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 646 c | Rsvd | Map-Version Number | EID-Prefix-AFI | 647 o +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 648 r | EID-Prefix | 649 d +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 650 | /| Priority | Weight | M Priority | M Weight | 651 | L +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 652 | o | Unused Flags |L|p|R| Loc-AFI | 653 | c +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 654 | \| Locator | 655 +-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 657 Packet field descriptions: 659 Type: 2 (Map-Reply) 661 P: This is the probe-bit, which indicates that the Map-Reply is in 662 response to a Locator reachability probe Map-Request. The 'Nonce' 663 field MUST contain a copy of the nonce value from the original 664 Map-Request. See RLOC-probing Section 7.1 for more details. When 665 the probe-bit is set to 1 in a Map-Reply message, the A-bit in 666 each EID-record included in the message MUST be set to 1. 668 E: This bit indicates that the ETR that sends this Map-Reply message 669 is advertising that the site is enabled for the Echo-Nonce Locator 670 reachability algorithm. See Echo-Nonce [I-D.ietf-lisp-rfc6830bis] 671 for more details. 673 S: This is the Security bit. When set to 1, the following 674 authentication information will be appended to the end of the Map- 675 Reply. The details of signing a Map-Reply message can be found in 676 [I-D.ietf-lisp-sec]. 678 0 1 2 3 679 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 1 680 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 681 | AD Type | Authentication Data Content . . . | 682 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 684 Reserved: This unassigned field MUST be set to 0 on transmit and 685 MUST be ignored on receipt. 687 Record Count: This is the number of records in this reply message. 688 A record is comprised of that portion of the packet labeled 689 'Record' above and occurs the number of times equal to Record 690 Count. 692 Nonce: This 64-bit value from the Map-Request is echoed in this 693 'Nonce' field of the Map-Reply. 695 Record TTL: This is the time in minutes the recipient of the Map- 696 Reply will store the mapping. If the TTL is 0, the entry MUST be 697 removed from the cache immediately. If the value is 0xffffffff, 698 the recipient can decide locally how long to store the mapping. 700 Locator Count: This is the number of Locator entries. A Locator 701 entry comprises what is labeled above as 'Loc'. The Locator count 702 can be 0, indicating that there are no Locators for the EID- 703 Prefix. 705 EID mask-len: This is the mask length for the EID-Prefix. 707 ACT: This 3-bit field describes Negative Map-Reply actions. In any 708 other message type, these bits are set to 0 and ignored on 709 receipt. These bits are used only when the 'Locator Count' field 710 is set to 0. The action bits are encoded only in Map-Reply 711 messages. They are used to tell an ITR or PITR why a empty 712 locator-set was returned from the mapping system and how it stores 713 the map-cache entry. 715 (0) No-Action: The Map-Cache is kept alive, and no packet 716 encapsulation occurs. 718 (1) Natively-Forward: The packet is not encapsulated or dropped 719 but natively forwarded. 721 (2) Send-Map-Request: The Map-Cache entry is created and flagged 722 that any packet matching this entry invokes sending a Map- 723 Request. 725 (3) Drop/No-Reason: A packet that matches this Map-Cache entry is 726 dropped. An ICMP Destination Unreachable message SHOULD be 727 sent. 729 (4) Drop/Policy-Denied: A packet that matches this Map-Cache 730 entry is dropped. The reason for the Drop action is that a 731 Map-Request for the target-EID is being policy denied by 732 either an xTR or the mapping system. 734 (5) Drop/Authentication-Failure: A packet that matches this Map- 735 Cache entry is dropped. The reason for the Drop action is 736 that a Map-Request for the target-EID fails an authentication 737 verification-check by either an xTR or the mapping system. 739 A: The Authoritative bit, when set to 1, is always set to 1 by an 740 ETR. When a Map-Server is proxy Map-Replying for a LISP site, the 741 Authoritative bit is set to 0. This indicates to requesting ITRs 742 that the Map-Reply was not originated by a LISP node managed at 743 the site that owns the EID-Prefix. 745 Map-Version Number: When this 12-bit value is non-zero, the Map- 746 Reply sender is informing the ITR what the version number is for 747 the EID record contained in the Map-Reply. The ETR can allocate 748 this number internally but MUST coordinate this value with other 749 ETRs for the site. When this value is 0, there is no versioning 750 information conveyed. The Map-Version Number can be included in 751 Map-Request and Map-Register messages. See Map-Versioning 752 [I-D.ietf-lisp-6834bis] for more details. 754 EID-Prefix-AFI: Address family of the EID-Prefix according to [AFI] 755 and [RFC8060]. 757 EID-Prefix: This prefix is 4 octets for an IPv4 address family and 758 16 octets for an IPv6 address family. 760 Priority: Each RLOC is assigned a unicast Priority. Lower values 761 are more preferable. When multiple RLOCs have the same Priority, 762 they may be used in a load-split fashion. A value of 255 means 763 the RLOC MUST NOT be used for unicast forwarding. 765 Weight: When priorities are the same for multiple RLOCs, the Weight 766 indicates how to balance unicast traffic between them. Weight is 767 encoded as a relative weight of total unicast packets that match 768 the mapping entry. For example, if there are 4 Locators in a 769 Locator-Set, where the Weights assigned are 30, 20, 20, and 10, 770 the first Locator will get 37.5% of the traffic, the 2nd and 3rd 771 Locators will get 25% of the traffic, and the 4th Locator will get 772 12.5% of the traffic. If all Weights for a Locator-Set are equal, 773 the receiver of the Map-Reply will decide how to load-split the 774 traffic. See RLOC-hashing [I-D.ietf-lisp-rfc6830bis] for a 775 suggested hash algorithm to distribute the load across Locators 776 with the same Priority and equal Weight values. 778 M Priority: Each RLOC is assigned a multicast Priority used by an 779 ETR in a receiver multicast site to select an ITR in a source 780 multicast site for building multicast distribution trees. A value 781 of 255 means the RLOC MUST NOT be used for joining a multicast 782 distribution tree. For more details, see [RFC6831]. 784 M Weight: When priorities are the same for multiple RLOCs, the 785 Weight indicates how to balance building multicast distribution 786 trees across multiple ITRs. The Weight is encoded as a relative 787 weight (similar to the unicast Weights) of the total number of 788 trees built to the source site identified by the EID-Prefix. If 789 all Weights for a Locator-Set are equal, the receiver of the Map- 790 Reply will decide how to distribute multicast state across ITRs. 791 For more details, see [RFC6831]. 793 Unused Flags: These are set to 0 when sending and ignored on 794 receipt. 796 L: When this bit is set, the Locator is flagged as a local Locator to 797 the ETR that is sending the Map-Reply. When a Map-Server is doing 798 proxy Map-Replying for a LISP site, the L-bit is set to 0 for all 799 Locators in this Locator-Set. 801 p: When this bit is set, an ETR informs the RLOC-Probing ITR that the 802 locator address for which this bit is set is the one being RLOC- 803 probed and may be different from the source address of the Map- 804 Reply. An ITR that RLOC-probes a particular Locator MUST use this 805 Locator for retrieving the data structure used to store the fact 806 that the Locator is reachable. The p-bit is set for a single 807 Locator in the same Locator-Set. If an implementation sets more 808 than one p-bit erroneously, the receiver of the Map-Reply MUST 809 select the first set p-bit Locator. The p-bit MUST NOT be set for 810 Locator-Set records sent in Map-Request and Map-Register messages. 812 R: This is set when the sender of a Map-Reply has a route to the 813 Locator in the Locator data record. This receiver may find this 814 useful to know if the Locator is up but not necessarily reachable 815 from the receiver's point of view. See also EID-Reachability 816 Section 7.1 for another way the R-bit may be used. 818 Locator: This is an IPv4 or IPv6 address (as encoded by the 'Loc- 819 AFI' field) assigned to an ETR and used by an ITR as a destination 820 RLOC address in the outer header of a LISP encapsualted packet. 822 Note that the destination RLOC address of a LISP encapsulated 823 packet MAY be an anycast address. A source RLOC of a LISP 824 encapsulated packet can be an anycast address as well. The source 825 or destination RLOC MUST NOT be the broadcast address 826 (255.255.255.255 or any subnet broadcast address known to the 827 router) and MUST NOT be a link-local multicast address. The 828 source RLOC MUST NOT be a multicast address. The destination RLOC 829 SHOULD be a multicast address if it is being mapped from a 830 multicast destination EID. 832 5.5. EID-to-RLOC UDP Map-Reply Message 834 A Map-Reply returns an EID-Prefix with a mask-length that is less 835 than or equal to the EID being requested. The EID being requested is 836 either from the destination field of an IP header of a Data-Probe or 837 the EID record of a Map-Request. The RLOCs in the Map-Reply are 838 routable IP addresses of all ETRs for the LISP site. Each RLOC 839 conveys status reachability but does not convey path reachability 840 from a requester's perspective. Separate testing of path 841 reachability is required. See RLOC-reachability Section 7.1 for 842 details. 844 Note that a Map-Reply MAY contain different EID-Prefix granularity 845 (prefix + mask-length) than the Map-Request that triggers it. This 846 might occur if a Map-Request were for a prefix that had been returned 847 by an earlier Map-Reply. In such a case, the requester updates its 848 cache with the new prefix information and granularity. For example, 849 a requester with two cached EID-Prefixes that are covered by a Map- 850 Reply containing one less-specific prefix replaces the entry with the 851 less-specific EID-Prefix. Note that the reverse, replacement of one 852 less-specific prefix with multiple more-specific prefixes, can also 853 occur, not by removing the less-specific prefix but rather by adding 854 the more-specific prefixes that, during a lookup, will override the 855 less-specific prefix. 857 When an EID moves out of a LISP site [I-D.ietf-lisp-eid-mobility], 858 the database mapping system may have overlapping EID-prefixes. Or 859 when a LISP site is configured with multiple sets of ETRs that 860 support different EID-prefix mask-lengths, the database mapping 861 system may have overlapping EID-prefixes. When overlapping EID- 862 prefixes exist, a Map-Request with an EID that best matches any EID- 863 Prefix MUST be returned in a single Map-Reply message. For instance, 864 if an ETR had database mapping entries for EID-Prefixes: 866 2001:db8::/16 867 2001:db8:1::/24 868 2001:db8:1:1::/32 869 2001:db8:1:2::/32 871 A Map-Request for EID 2001:db8:1:1::1 would cause a Map-Reply with a 872 record count of 1 to be returned with a mapping record EID-Prefix of 873 2001:db8:1:1::/32. 875 A Map-Request for EID 2001:db8:1:5::5 would cause a Map-Reply with a 876 record count of 3 to be returned with mapping records for EID- 877 Prefixes 2001:db8:1::/24, 2001:db8:1:1::/32, 2001:db8:1:2::/32, 878 filling out the /24 with more-specifics that exist in the mapping 879 system. 881 Note that not all overlapping EID-Prefixes need to be returned but 882 only the more-specific entries (note that in the second example above 883 2001:db8::/16 was not returned for requesting EID 2001:db8:1:5::5) 884 for the matching EID-Prefix of the requesting EID. When more than 885 one EID-Prefix is returned, all SHOULD use the same Time to Live 886 value so they can all time out at the same time. When a more- 887 specific EID-Prefix is received later, its Time to Live value in the 888 Map-Reply record can be stored even when other less-specific entries 889 exist. When a less-specific EID-Prefix is received later, its Map- 890 Cache expiration time SHOULD be set to the minimum expiration time of 891 any more-specific EID-Prefix in the Map-Cache. This is done so the 892 integrity of the EID-Prefix set is wholly maintained and so no more- 893 specific entries are removed from the Map-Cache while keeping less- 894 specific entries. 896 Map-Replies SHOULD be sent for an EID-Prefix no more often than once 897 per second to the same requesting router. For scalability, it is 898 expected that aggregation of EID addresses into EID-Prefixes will 899 allow one Map-Reply to satisfy a mapping for the EID addresses in the 900 prefix range, thereby reducing the number of Map-Request messages. 902 Map-Reply records can have an empty Locator-Set. A Negative Map- 903 Reply is a Map-Reply with an empty Locator-Set. Negative Map-Replies 904 convey special actions by the sender to the ITR or PITR that have 905 solicited the Map-Reply. There are two primary applications for 906 Negative Map-Replies. The first is for a Map-Resolver to instruct an 907 ITR or PITR when a destination is for a LISP site versus a non-LISP 908 site, and the other is to source quench Map-Requests that are sent 909 for non-allocated EIDs. 911 For each Map-Reply record, the list of Locators in a Locator-Set MUST 912 appear in the same order for each ETR that originates a Map-Reply 913 message. The Locator-Set MUST be sorted in order of ascending IP 914 address where an IPv4 locator address is considered numerically 'less 915 than' an IPv6 locator address. 917 When sending a Map-Reply message, the destination address is copied 918 from one of the 'ITR-RLOC' fields from the Map-Request. The ETR can 919 choose a locator address from one of the address families it 920 supports. For Data-Probes, the destination address of the Map-Reply 921 is copied from the source address of the Data-Probe message that is 922 invoking the reply. The source address of the Map-Reply is one of 923 the local IP addresses chosen, to allow Unicast Reverse Path 924 Forwarding (uRPF) checks to succeed in the upstream service provider. 925 The destination port of a Map-Reply message is copied from the source 926 port of the Map-Request or Data-Probe, and the source port of the 927 Map-Reply message is set to the well-known UDP port 4342. 929 5.6. Map-Register Message Format 931 This section specifies the encoding format for the Map-Register 932 message. The message is sent in UDP with a destination UDP port of 933 4342 and a randomly selected UDP source port number. 935 The fields below are used in multiple control messages. They are 936 defined for Map-Register, Map-Notify and Map-Notify-Ack message 937 types. 939 The Map-Register message format is: 941 0 1 2 3 942 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 1 943 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 944 |Type=3 |P|S|I| Reserved |E|T|a|R|M| Record Count | 945 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 946 | Nonce . . . | 947 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 948 | . . . Nonce | 949 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 950 | Key ID | Algorithm ID | Authentication Data Length | 951 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 952 ~ Authentication Data ~ 953 +-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 954 | | Record TTL | 955 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 956 R | Locator Count | EID mask-len | ACT |A| Reserved | 957 e +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 958 c | Rsvd | Map-Version Number | EID-Prefix-AFI | 959 o +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 960 r | EID-Prefix | 961 d +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 962 | /| Priority | Weight | M Priority | M Weight | 963 | L +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 964 | o | Unused Flags |L|p|R| Loc-AFI | 965 | c +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 966 | \| Locator | 967 +-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 969 Packet field descriptions: 971 Type: 3 (Map-Register) 973 P: This is the proxy Map-Reply bit. When set to 1, an ETR sends a 974 Map-Register message requesting the Map-Server to proxy a Map- 975 Reply. The Map-Server will send non-authoritative Map-Replies on 976 behalf of the ETR. 978 S: This is the security-capable bit. When set, the procedures from 979 [I-D.ietf-lisp-sec] are supported. 981 I: This bit is set to 1 to indicate that a 128 bit xTR-ID and a 64 982 bit Site-ID fields are present at the end of the Map-Register 983 message. If an xTR is configured with an xTR-ID and Site-ID, it 984 MUST set the I bit to 1 and include its xTR-ID and Site-ID in the 985 Map-Register messages it generates. The combination of Site-ID 986 plus xTR-ID uniquely identifies an xTR in a LISP domain and serves 987 to track its last seen nonce. 989 Reserved: This unassigned field MUST be set to 0 on transmit and 990 MUST be ignored on receipt. 992 E: This is the Map-Register EID-notify bit. This is used by a First- 993 Hop-Router (FHR) which discovers a dynamic-EID. This EID-notify 994 based Map-Register is sent by the FHR to the same site xTR that 995 propogates the Map-Register to the mapping system. The site xTR 996 keeps state to later Map-Notify the FHR after the EID has moves 997 away. See [I-D.ietf-lisp-eid-mobility] for a detailed use-case. 999 T: This is the use-TTL for timeout bit. When set to 1, the xTR wants 1000 the Map-Server to time out registrations based on the value in the 1001 "Record TTL" field of this message. Otherwise, the default 1002 timeout described in Section 8.2 is used. 1004 a: This is the merge-request bit. When set to 1, the xTR requests to 1005 merge RLOC-records from different xTRs registering the same EID- 1006 record. See signal-free multicast [RFC8378] for one use case 1007 example. 1009 R: This reserved and unassigned bit MUST be set to 0 on transmit and 1010 MUST be ignored on receipt. 1012 M: This is the want-map-notify bit. When set to 1, an ETR is 1013 requesting a Map-Notify message to be returned in response to 1014 sending a Map-Register message. The Map-Notify message sent by a 1015 Map-Server is used to acknowledge receipt of a Map-Register 1016 message. 1018 Record Count: This is the number of records in this Map-Register 1019 message. A record is comprised of that portion of the packet 1020 labeled 'Record' above and occurs the number of times equal to 1021 Record Count. 1023 Nonce: This 8-octet 'Nonce' field is incremented each time a Map- 1024 Register message is sent. When a Map-Register acknowledgement is 1025 requested, the nonce is returned by Map-Servers in Map-Notify 1026 messages. Since the entire Map-Register message is authenticated, 1027 the 'Nonce' field serves to protect against Map-Register replay 1028 attacks. An ETR that registers to the mapping system SHOULD store 1029 the last nonce sent in persistent storage so when it restarts it 1030 can continue using an incrementing nonce. If the the ETR cannot 1031 support saving the nonce, then when it restarts it MUST use a new 1032 authentication key to register to the mapping system. A Map- 1033 Server MUST track and save in persistent storage the last nonce 1034 received for each ETR xTR-ID that registers to it. If a Map- 1035 Register is received with a nonce value that is not greater than 1036 the saved nonce, it drops the Map-Register message and logs the 1037 fact a replay attack could have occurred. 1039 Key ID: This is a configured key-id value that corresponds to a 1040 shared-secret password that is used to authenticate the sender. 1041 Multiple shared-secrets can be used to roll over keys in a non- 1042 disruptive way. 1044 Algorithm ID: This is the configured Message Authentication Code 1045 (MAC) algorithm value used for the authentication function. See 1046 Algorithm ID Numbers in the Section 12.5 for codepoint 1047 assignments. 1049 Authentication Data Length: This is the length in octets of the 1050 'Authentication Data' field that follows this field. The length 1051 of the 'Authentication Data' field is dependent on the MAC 1052 algorithm used. The length field allows a device that doesn't 1053 know the MAC algorithm to correctly parse the packet. 1055 Authentication Data: This is the output of the MAC algorithm. The 1056 entire Map-Register payload (from and including the LISP message 1057 type field through the end of the last RLOC record) is 1058 authenticated with this field preset to 0. After the MAC is 1059 computed, it is placed in this field. Implementations of this 1060 specification MUST include support for either HMAC-SHA-1-96 1061 [RFC2404] and HMAC-SHA-256-128 [RFC4868] where the latter is 1062 RECOMMENDED. 1064 The definition of the rest of the Map-Register can be found in EID- 1065 record description in Section 5.4. When the I-bit is set, the 1066 following fields are added to the end of thd Map-Register message: 1068 xTR-ID: xTR-ID is a 128 bit field at the end of the Map-Register 1069 message, starting after the final Record in the message. The xTR- 1070 ID is used to uniquely identify a xTR. The same xTR-ID value MUST 1071 NOT be used in two different xTRs. 1073 Site-ID: Site-ID is a 64 bit field at the end of the Map- Register 1074 message, following the xTR-ID. Site-ID is used to uniquely 1075 identify to which site the xTR that sent the message belongs. 1077 5.7. Map-Notify/Map-Notify-Ack Message Format 1079 This section specifies the encoding format for the Map-Notify and 1080 Map-Notify-Ack messages. The messages are sent inside a UDP packet 1081 with source and destination UDP ports equal to 4342. 1083 The Map-Notify and Map-Notify-Ack message formats are: 1085 0 1 2 3 1086 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 1087 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1088 |Type=4/5| Reserved | Record Count | 1089 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1090 | Nonce . . . | 1091 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1092 | . . . Nonce | 1093 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1094 | Key ID | Algorithm ID | Authentication Data Length | 1095 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1096 ~ Authentication Data ~ 1097 +-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1098 | | Record TTL | 1099 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1100 R | Locator Count | EID mask-len | ACT |A| Reserved | 1101 e +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1102 c | Rsvd | Map-Version Number | EID-Prefix-AFI | 1103 o +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1104 r | EID-Prefix | 1105 d +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1106 | /| Priority | Weight | M Priority | M Weight | 1107 | L +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1108 | o | Unused Flags |L|p|R| Loc-AFI | 1109 | c +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1110 | \| Locator | 1111 +-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1113 Packet field descriptions: 1115 Type: 4/5 (Map-Notify/Map-Notify-Ack) 1117 The Map-Notify message has the same contents as a Map-Register 1118 message. See the Map-Register section for field descriptions and the 1119 Map-Reply section for EID-record and RLOC-record descriptions. 1121 The Map-Notify-Ack message has the same contents as a Map-Notify 1122 message. It is used to acknowledge the receipt of a Map-Notify 1123 (solicited or unsolicited) and for the sender to stop retransmitting 1124 a Map-Notify with the same nonce. 1126 A Map-Server sends an unsolicited Map-Notify message (one that is not 1127 used as an acknowledgment to a Map-Register message) that follows the 1128 Congestion Control And Relability Guideline sections of [RFC8085]. A 1129 Map-Notify is retransmitted until a Map-Notify-Ack is received by the 1130 Map-Server with the same nonce used in the Map-Notify message. If a 1131 Map-Notify-Ack is never received by the Map-Server, it issues a log 1132 message. An implementation SHOULD retransmit up to 3 times at 3 1133 second retransmission intervals, after which time the retransmission 1134 interval is exponentially backed-off for another 3 retransmission 1135 attempts. After this time, an xTR can only get the RLOC-set change 1136 by later querying the mapping system or by RLOC-probing one of the 1137 RLOCs of the existing cached RLOC-set to get the new RLOC-set. 1139 5.8. Encapsulated Control Message Format 1141 An Encapsulated Control Message (ECM) is used to encapsulate control 1142 packets sent between xTRs and the mapping database system. 1144 0 1 2 3 1145 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 1146 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1147 / | IPv4 or IPv6 Header | 1148 OH | (uses RLOC addresses) | 1149 \ | | 1150 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1151 / | Source Port = xxxx | Dest Port = 4342 | 1152 UDP +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1153 \ | UDP Length | UDP Checksum | 1154 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1155 LISP |Type=8 |S|D|E|M| Reserved | 1156 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1157 / | IPv4 or IPv6 Header | 1158 IH | (uses RLOC or EID addresses) | 1159 \ | | 1160 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1161 / | Source Port = xxxx | Dest Port = yyyy | 1162 UDP +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1163 \ | UDP Length | UDP Checksum | 1164 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1165 LCM | LISP Control Message | 1166 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1168 Packet header descriptions: 1170 OH: The outer IPv4 or IPv6 header, which uses RLOC addresses in the 1171 source and destination header address fields. 1173 UDP: The outer UDP header with destination port 4342. The source 1174 port is randomly allocated. The checksum field MUST be non- 1175 zero. 1177 LISP: Type 8 is defined to be a "LISP Encapsulated Control Message", 1178 and what follows is either an IPv4 or IPv6 header as encoded by 1179 the first 4 bits after the 'Reserved' field. 1181 Type: 8 (Encapsulated Control Message (ECM)) 1183 S: This is the Security bit. When set to 1, the field following 1184 the 'Reserved' field will have the following Authentication 1185 Data format and follow the procedures from [I-D.ietf-lisp-sec]. 1187 0 1 2 3 1188 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 1189 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1190 | AD Type | Authentication Data Content . . . | 1191 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1193 D: This is the DDT-bit. When set to 1, the sender is requesting a 1194 Map-Referral message to be returned. The details of this 1195 procedure are described in [RFC8111]. 1197 E: This is the to-ETR bit. When set to 1, the Map-Server's 1198 intention is to forward the ECM to an authoritative ETR. 1200 M: This is the to-MS bit. When set to 1, a Map-Request is being 1201 sent to a co-located Map-Resolver and Map-Server where the 1202 message can be processed directly by the Map-Server versus the 1203 Map-Resolver using the LISP-DDT procedures in [RFC8111]. 1205 IH: The inner IPv4 or IPv6 header, which can use either RLOC or EID 1206 addresses in the header address fields. When a Map-Request is 1207 encapsulated in this packet format, the destination address in 1208 this header is an EID. 1210 UDP: The inner UDP header, where the port assignments depend on the 1211 control packet being encapsulated. When the control packet is 1212 a Map-Request or Map-Register, the source port is selected by 1213 the ITR/PITR and the destination port is 4342. When the 1214 control packet is a Map-Reply, the source port is 4342 and the 1215 destination port is assigned from the source port of the 1216 invoking Map-Request. Port number 4341 MUST NOT be assigned to 1217 either port. The checksum field MUST be non-zero. 1219 LCM: The format is one of the control message formats described in 1220 this section. Map-Request messages are allowed to be Control- 1221 Plane (ECM) encapsulated. When Map-Requests are sent for RLOC- 1222 Probing purposes (i.e. the probe-bit is set), they MUST NOT be 1223 sent inside Encapsulated Control Messages. PIM Join/Prune 1224 messages [RFC6831] are also allowed to be Control-Plane (ECM) 1225 encapsulated. 1227 6. Changing the Contents of EID-to-RLOC Mappings 1229 In the LISP architecture ITRs/PITRs use a local Map-Cache to store 1230 EID-to-RLOC mappings for forwarding. When an ETR updates a mapping a 1231 mechanism is required to inform ITRs/PITRs that are using such 1232 mappings. 1234 The LISP Data-Plane defines several mechanism to update mappings 1235 [I-D.ietf-lisp-rfc6830bis]. This document specifies the Solicit-Map 1236 Request (SMR), a Control-Plane push-based mechanism. An additional 1237 Control-Plane mechanism based on the Publish/subscribe paradigm is 1238 specified in [I-D.ietf-lisp-pubsub]. 1240 6.1. Solicit-Map-Request (SMR) 1242 Soliciting a Map-Request is a selective way for ETRs, at the site 1243 where mappings change, to control the rate they receive requests for 1244 Map-Reply messages. SMRs are also used to tell remote ITRs to update 1245 the mappings they have cached. 1247 Since ETRs are not required to keep track of remote ITRs that have 1248 cached their mappings, they do not know which ITRs need to have their 1249 mappings updated. As a result, an ETR will solicit Map-Requests 1250 (called an SMR message) to those sites to which it has been sending 1251 LISP encapsulated data packets for the last minute. In particular, 1252 an ETR will send an SMR to an ITR to which it has recently sent 1253 encapsulated data. This can only occur when both ITR and ETR 1254 functionality reside in the same router. 1256 An SMR message is simply a bit set in a Map-Request message. An ITR 1257 or PITR will send a Map-Request when they receive an SMR message. 1258 Both the SMR sender and the Map-Request responder MUST rate-limit 1259 these messages. Rate-limiting can be implemented as a global rate- 1260 limiter or one rate-limiter per SMR destination. 1262 The following procedure shows how an SMR exchange occurs when a site 1263 is doing Locator-Set compaction for an EID-to-RLOC mapping: 1265 1. When the database mappings in an ETR change, the ETRs at the site 1266 begin to send Map-Requests with the SMR bit set for each Locator 1267 in each Map-Cache entry the ETR (when it is an xTR co-located as 1268 an ITR) caches. 1270 2. A remote ITR that receives the SMR message will schedule sending 1271 a Map-Request message to the source locator address of the SMR 1272 message or to the mapping database system. A newly allocated 1273 random nonce is selected, and the EID-Prefix used is the one 1274 copied from the SMR message. If the source Locator is the only 1275 Locator in the cached Locator-Set, the remote ITR SHOULD send a 1276 Map-Request to the database mapping system just in case the 1277 single Locator has changed and may no longer be reachable to 1278 accept the Map-Request. 1280 3. The remote ITR MUST rate-limit the Map-Request until it gets a 1281 Map-Reply while continuing to use the cached mapping. When 1282 Map-Versioning as described in [I-D.ietf-lisp-6834bis] is used, 1283 an SMR sender can detect if an ITR is using the most up-to-date 1284 database mapping. 1286 4. The site sending SMR messages will reply to the Map-Request with 1287 a Map-Reply message that has a nonce from the SMR-invoked Map- 1288 Request. The Map-Reply messages MUST be rate-limited according 1289 to procedures in [RFC8085]. This is important to avoid Map-Reply 1290 implosion. 1292 5. The ETRs at the site with the changed mapping record the fact 1293 that the site that sent the Map-Request has received the new 1294 mapping data in the Map-Cache entry for the remote site so the 1295 Locator-Status-Bits are reflective of the new mapping for packets 1296 going to the remote site. The ETR then stops sending SMR 1297 messages. 1299 For security reasons, an ITR MUST NOT process unsolicited Map- 1300 Replies. To avoid Map-Cache entry corruption by a third party, a 1301 sender of an SMR-based Map-Request MUST be verified. If an ITR 1302 receives an SMR-based Map-Request and the source is not in the 1303 Locator-Set for the stored Map-Cache entry, then the responding Map- 1304 Request MUST be sent with an EID destination to the mapping database 1305 system. Since the mapping database system is a more secure way to 1306 reach an authoritative ETR, it will deliver the Map-Request to the 1307 authoritative source of the mapping data. 1309 When an ITR receives an SMR-based Map-Request for which it does not 1310 have a cached mapping for the EID in the SMR message, it SHOULD NOT 1311 send an SMR-invoked Map-Request. This scenario can occur when an ETR 1312 sends SMR messages to all Locators in the Locator-Set it has stored 1313 in its Map-Cache but the remote ITRs that receive the SMR may not be 1314 sending packets to the site. There is no point in updating the ITRs 1315 until they need to send, in which case they will send Map-Requests to 1316 obtain a Map-Cache entry. 1318 7. Routing Locator Reachability 1320 This document defines several Control-Plane mechanisms for 1321 determining RLOC reachability. Please note that additional Data- 1322 Plane reachability mechanisms are defined in 1323 [I-D.ietf-lisp-rfc6830bis]. 1325 1. An ITR may receive an ICMP Network Unreachable or Host 1326 Unreachable message for an RLOC it is using. This indicates that 1327 the RLOC is likely down. Note that trusting ICMP messages may 1328 not be desirable, but neither is ignoring them completely. 1329 Implementations are encouraged to follow current best practices 1330 in treating these conditions [I-D.ietf-opsec-icmp-filtering]. 1332 2. When an ITR participates in the routing protocol that operates in 1333 the underlay routing system, it can determine that an RLOC is 1334 down when no Routing Information Base (RIB) entry exists that 1335 matches the RLOC IP address. 1337 3. An ITR may receive an ICMP Port Unreachable message from a 1338 destination host. This occurs if an ITR attempts to use 1339 interworking [RFC6832] and LISP-encapsulated data is sent to a 1340 non-LISP-capable site. 1342 4. An ITR may receive a Map-Reply from an ETR in response to a 1343 previously sent Map-Request. The RLOC source of the Map-Reply is 1344 likely up, since the ETR was able to send the Map-Reply to the 1345 ITR. 1347 5. An ITR/ETR pair can use the 'RLOC-Probing' mechanism described 1348 below. 1350 When ITRs receive ICMP Network Unreachable or Host Unreachable 1351 messages as a method to determine unreachability, they will refrain 1352 from using Locators that are described in Locator lists of Map- 1353 Replies. However, using this approach is unreliable because many 1354 network operators turn off generation of ICMP Destination Unreachable 1355 messages. 1357 If an ITR does receive an ICMP Network Unreachable or Host 1358 Unreachable message, it MAY originate its own ICMP Destination 1359 Unreachable message destined for the host that originated the data 1360 packet the ITR encapsulated. 1362 Also, BGP-enabled ITRs can unilaterally examine the RIB to see if a 1363 locator address from a Locator-Set in a mapping entry matches a 1364 prefix. If it does not find one and BGP is running in the Default- 1365 Free Zone (DFZ), it can decide to not use the Locator even though the 1366 Locator-Status-Bits indicate that the Locator is up. In this case, 1367 the path from the ITR to the ETR that is assigned the Locator is not 1368 available. More details are in [I-D.meyer-loc-id-implications]. 1370 Optionally, an ITR can send a Map-Request to a Locator, and if a Map- 1371 Reply is returned, reachability of the Locator has been determined. 1372 Obviously, sending such probes increases the number of control 1373 messages originated by Tunnel Routers for active flows, so Locators 1374 are assumed to be reachable when they are advertised. 1376 This assumption does create a dependency: Locator unreachability is 1377 detected by the receipt of ICMP Host Unreachable messages. When a 1378 Locator has been determined to be unreachable, it is not used for 1379 active traffic; this is the same as if it were listed in a Map-Reply 1380 with Priority 255. 1382 The ITR can test the reachability of the unreachable Locator by 1383 sending periodic Requests. Both Requests and Replies MUST be rate- 1384 limited. Locator reachability testing is never done with data 1385 packets, since that increases the risk of packet loss for end-to-end 1386 sessions. 1388 7.1. RLOC-Probing Algorithm 1390 RLOC-Probing is a method that an ITR or PITR can use to determine the 1391 reachability status of one or more Locators that it has cached in a 1392 Map-Cache entry. The probe-bit of the Map-Request and Map-Reply 1393 messages is used for RLOC-Probing. 1395 RLOC-Probing is done in the control plane on a timer basis, where an 1396 ITR or PITR will originate a Map-Request destined to a locator 1397 address from one of its own locator addresses. A Map-Request used as 1398 an RLOC-probe is NOT encapsulated and NOT sent to a Map-Server or to 1399 the mapping database system as one would when soliciting mapping 1400 data. The EID record encoded in the Map-Request is the EID-Prefix of 1401 the Map-Cache entry cached by the ITR or PITR. The ITR MAY include a 1402 mapping data record for its own database mapping information that 1403 contains the local EID-Prefixes and RLOCs for its site. RLOC-probes 1404 are sent periodically using a jittered timer interval. 1406 When an ETR receives a Map-Request message with the probe-bit set, it 1407 returns a Map-Reply with the probe-bit set. The source address of 1408 the Map-Reply is set to the IP address of the outgoing interface the 1409 Map-Reply destination address routes to. The Map-Reply SHOULD 1410 contain mapping data for the EID-Prefix contained in the Map-Request. 1411 This provides the opportunity for the ITR or PITR that sent the RLOC- 1412 probe to get mapping updates if there were changes to the ETR's 1413 database mapping entries. 1415 There are advantages and disadvantages of RLOC-Probing. The main 1416 benefit of RLOC-Probing is that it can handle many failure scenarios 1417 allowing the ITR to determine when the path to a specific Locator is 1418 reachable or has become unreachable, thus providing a robust 1419 mechanism for switching to using another Locator from the cached 1420 Locator. RLOC-Probing can also provide rough Round-Trip Time (RTT) 1421 estimates between a pair of Locators, which can be useful for network 1422 management purposes as well as for selecting low delay paths. The 1423 major disadvantage of RLOC-Probing is in the number of control 1424 messages required and the amount of bandwidth used to obtain those 1425 benefits, especially if the requirement for failure detection times 1426 is very small. 1428 8. Interactions with Other LISP Components 1430 8.1. ITR EID-to-RLOC Mapping Resolution 1432 An ITR is configured with one or more Map-Resolver addresses. These 1433 addresses are "Locators" (or RLOCs) and MUST be routable on the 1434 underlying core network; they MUST NOT need to be resolved through 1435 LISP EID-to-RLOC mapping, as that would introduce a circular 1436 dependency. When using a Map-Resolver, an ITR does not need to 1437 connect to any other database mapping system. In particular, the ITR 1438 need not connect to the LISP-ALT infrastructure or implement the BGP 1439 and GRE protocols that it uses. 1441 An ITR sends an Encapsulated Map-Request to a configured Map-Resolver 1442 when it needs an EID-to-RLOC mapping that is not found in its local 1443 Map-Cache. Using the Map-Resolver greatly reduces both the 1444 complexity of the ITR implementation and the costs associated with 1445 its operation. 1447 In response to an Encapsulated Map-Request, the ITR can expect one of 1448 the following: 1450 o An immediate Negative Map-Reply (with action code of "Natively- 1451 Forward", 15-minute Time to Live (TTL)) from the Map-Resolver if 1452 the Map-Resolver can determine that the requested EID does not 1453 exist. The ITR saves the EID-Prefix returned in the Map-Reply in 1454 its cache, marks it as non-LISP-capable, and knows not to attempt 1455 LISP encapsulation for destinations matching it. 1457 o A Negative Map-Reply, with action code of "Natively-Forward", from 1458 a Map-Server that is authoritative for an EID-Prefix that matches 1459 the requested EID but that does not have an actively registered, 1460 more-specific ID-prefix. In this case, the requested EID is said 1461 to match a "hole" in the authoritative EID-Prefix. If the 1462 requested EID matches a more-specific EID-Prefix that has been 1463 delegated by the Map-Server but for which no ETRs are currently 1464 registered, a 1-minute TTL is returned. If the requested EID 1465 matches a non-delegated part of the authoritative EID-Prefix, then 1466 it is not a LISP EID and a 15-minute TTL is returned. See 1467 Section 8.2 for discussion of aggregate EID-Prefixes and details 1468 of Map-Server EID-Prefix matching. 1470 o A LISP Map-Reply from the ETR that owns the EID-to-RLOC mapping or 1471 possibly from a Map-Server answering on behalf of the ETR. See 1472 Section 8.4 for more details on Map-Resolver message processing. 1474 Note that an ITR may be configured to both use a Map-Resolver and to 1475 participate in a LISP-ALT logical network. In such a situation, the 1476 ITR SHOULD send Map-Requests through the ALT network for any EID- 1477 Prefix learned via ALT BGP. Such a configuration is expected to be 1478 very rare, since there is little benefit to using a Map-Resolver if 1479 an ITR is already using LISP-ALT. There would be, for example, no 1480 need for such an ITR to send a Map-Request to a possibly non-existent 1481 EID (and rely on Negative Map-Replies) if it can consult the ALT 1482 database to verify that an EID-Prefix is present before sending that 1483 Map-Request. 1485 8.2. EID-Prefix Configuration and ETR Registration 1487 An ETR publishes its EID-Prefixes on a Map-Server by sending LISP 1488 Map-Register messages. A Map-Register message includes 1489 authentication data, so prior to sending a Map-Register message, the 1490 ETR and Map-Server SHOULD be configured with a shared secret or other 1491 relevant authentication information. A Map-Server's configuration 1492 SHOULD also include a list of the EID-Prefixes for which each ETR is 1493 authoritative. Upon receipt of a Map-Register from an ETR, a Map- 1494 Server accepts only EID-Prefixes that are configured for that ETR. 1495 Failure to implement such a check would leave the mapping system 1496 vulnerable to trivial EID-Prefix hijacking attacks. As developers 1497 and operators gain experience with the mapping system, additional, 1498 stronger security measures may be added to the registration process. 1500 In addition to the set of EID-Prefixes defined for each ETR that may 1501 register, a Map-Server is typically also configured with one or more 1502 aggregate prefixes that define the part of the EID numbering space 1503 assigned to it. When LISP-ALT is the database in use, aggregate EID- 1504 Prefixes are implemented as discard routes and advertised into ALT 1505 BGP. The existence of aggregate EID-Prefixes in a Map-Server's 1506 database means that it may receive Map Requests for EID-Prefixes that 1507 match an aggregate but do not match a registered prefix; Section 8.3 1508 describes how this is handled. 1510 Map-Register messages are sent periodically from an ETR to a Map- 1511 Server with a suggested interval between messages of one minute. A 1512 Map-Server SHOULD time out and remove an ETR's registration if it has 1513 not received a valid Map-Register message within the past 1514 three minutes. When first contacting a Map-Server after restart or 1515 changes to its EID-to-RLOC database mappings, an ETR MAY initially 1516 send Map-Register messages at an increased frequency, up to one every 1517 20 seconds. This "quick registration" period is limited to 1518 five minutes in duration. 1520 An ETR MAY request that a Map-Server explicitly acknowledge receipt 1521 and processing of a Map-Register message by setting the "want-map- 1522 notify" (M-bit) flag. A Map-Server that receives a Map-Register with 1523 this flag set will respond with a Map-Notify message. Typical use of 1524 this flag by an ETR would be to set it for Map-Register messages sent 1525 during the initial "quick registration" with a Map-Server but then 1526 set it only occasionally during steady-state maintenance of its 1527 association with that Map-Server. Note that the Map-Notify message 1528 is sent to UDP destination port 4342, not to the source port 1529 specified in the original Map-Register message. 1531 Note that a one-minute minimum registration interval during 1532 maintenance of an ETR-Map-Server association places a lower bound on 1533 how quickly and how frequently a mapping database entry can be 1534 updated. This may have implications for what sorts of mobility can 1535 be supported directly by the mapping system; shorter registration 1536 intervals or other mechanisms might be needed to support faster 1537 mobility in some cases. For a discussion on one way that faster 1538 mobility may be implemented for individual devices, please see 1539 [I-D.ietf-lisp-mn]. 1541 An ETR MAY also request, by setting the "proxy Map-Reply" flag 1542 (P-bit) in the Map-Register message, that a Map-Server answer Map- 1543 Requests instead of forwarding them to the ETR. See Section 7.1 for 1544 details on how the Map-Server sets certain flags (such as those 1545 indicating whether the message is authoritative and how returned 1546 Locators SHOULD be treated) when sending a Map-Reply on behalf of an 1547 ETR. When an ETR requests proxy reply service, it SHOULD include all 1548 RLOCs for all ETRs for the EID-Prefix being registered, along with 1549 the routable flag ("R-bit") setting for each RLOC. The Map-Server 1550 includes all of this information in Map-Reply messages that it sends 1551 on behalf of the ETR. This differs from a non-proxy registration, 1552 since the latter need only provide one or more RLOCs for a Map-Server 1553 to use for forwarding Map-Requests; the registration information is 1554 not used in Map-Replies, so it being incomplete is not incorrect. 1556 An ETR that uses a Map-Server to publish its EID-to-RLOC mappings 1557 does not need to participate further in the mapping database 1558 protocol(s). When using a LISP-ALT mapping database, for example, 1559 this means that the ETR does not need to implement GRE or BGP, which 1560 greatly simplifies its configuration and reduces its cost of 1561 operation. 1563 Note that use of a Map-Server does not preclude an ETR from also 1564 connecting to the mapping database (i.e., it could also connect to 1565 the LISP-ALT network), but doing so doesn't seem particularly useful, 1566 as the whole purpose of using a Map-Server is to avoid the complexity 1567 of the mapping database protocols. 1569 8.3. Map-Server Processing 1571 Once a Map-Server has EID-Prefixes registered by its client ETRs, it 1572 can accept and process Map-Requests for them. 1574 In response to a Map-Request (received over the ALT if LISP-ALT is in 1575 use), the Map-Server first checks to see if the destination EID 1576 matches a configured EID-Prefix. If there is no match, the Map- 1577 Server returns a Negative Map-Reply with action code "Natively- 1578 Forward" and a 15-minute TTL. This can occur if a Map Request is 1579 received for a configured aggregate EID-Prefix for which no more- 1580 specific EID-Prefix exists; it indicates the presence of a non-LISP 1581 "hole" in the aggregate EID-Prefix. 1583 Next, the Map-Server checks to see if any ETRs have registered the 1584 matching EID-Prefix. If none are found, then the Map-Server returns 1585 a Negative Map-Reply with action code "Natively-Forward" and a 1586 1-minute TTL. 1588 If the EID-prefix is either registered or not registered to the 1589 mapping system and there is a policy in the Map-Server to have the 1590 requestor drop packets for the matching EID-prefix, then a Drop/ 1591 Policy-Denied action is returned. If the EID-prefix is registered or 1592 not registered and there is a authentication failure, then a Drop/ 1593 Authentication- failure action is returned. If either of these 1594 actions result as a temporary state in policy or authentication then 1595 a Send-Map-Request action with 1-minute TTL MAY be returned to allow 1596 the requestor to retry the Map-Request. 1598 If any of the registered ETRs for the EID-Prefix have requested proxy 1599 reply service, then the Map-Server answers the request instead of 1600 forwarding it. It returns a Map-Reply with the EID-Prefix, RLOCs, 1601 and other information learned through the registration process. 1603 If none of the ETRs have requested proxy reply service, then the Map- 1604 Server re-encapsulates and forwards the resulting Encapsulated Map- 1605 Request to one of the registered ETRs. It does not otherwise alter 1606 the Map-Request, so any Map-Reply sent by the ETR is returned to the 1607 RLOC in the Map-Request, not to the Map-Server. Unless also acting 1608 as a Map-Resolver, a Map-Server should never receive Map-Replies; any 1609 such messages SHOULD be discarded without response, perhaps 1610 accompanied by the logging of a diagnostic message if the rate of 1611 Map-Replies is suggestive of malicious traffic. 1613 8.4. Map-Resolver Processing 1615 Upon receipt of an Encapsulated Map-Request, a Map-Resolver 1616 decapsulates the enclosed message and then searches for the requested 1617 EID in its local database of mapping entries (statically configured 1618 or learned from associated ETRs if the Map-Resolver is also a Map- 1619 Server offering proxy reply service). If it finds a matching entry, 1620 it returns a LISP Map-Reply with the known mapping. 1622 If the Map-Resolver does not have the mapping entry and if it can 1623 determine that the EID is not in the mapping database (for example, 1624 if LISP-ALT is used, the Map-Resolver will have an ALT forwarding 1625 table that covers the full EID space), it immediately returns a 1626 negative LISP Map-Reply, with action code "Natively-Forward" and a 1627 15-minute TTL. To minimize the number of negative cache entries 1628 needed by an ITR, the Map-Resolver SHOULD return the least-specific 1629 prefix that both matches the original query and does not match any 1630 EID-Prefix known to exist in the LISP-capable infrastructure. 1632 If the Map-Resolver does not have sufficient information to know 1633 whether the EID exists, it needs to forward the Map-Request to 1634 another device that has more information about the EID being 1635 requested. To do this, it forwards the unencapsulated Map-Request, 1636 with the original ITR RLOC as the source, to the mapping database 1637 system. Using LISP-ALT, the Map-Resolver is connected to the ALT 1638 network and sends the Map-Request to the next ALT hop learned from 1639 its ALT BGP neighbors. The Map-Resolver does not send any response 1640 to the ITR; since the source RLOC is that of the ITR, the ETR or Map- 1641 Server that receives the Map-Request over the ALT and responds will 1642 do so directly to the ITR. 1644 8.4.1. Anycast Operation 1646 A Map-Resolver can be set up to use "anycast", where the same address 1647 is assigned to multiple Map-Resolvers and is propagated through IGP 1648 routing, to facilitate the use of a topologically close Map-Resolver 1649 by each ITR. 1651 ETRs MAY have anycast RLOC addresses which are registered as part of 1652 their RLOC-set to the mapping system. However, registrations MUST 1653 use their unique RLOC addresses or distinct authentication keys to 1654 identify security associations with the Map-Servers. 1656 9. Security Considerations 1658 A complete LISP threat analysis can be found in [RFC7835]. In what 1659 follows we highlight security considerations that apply when LISP is 1660 deployed in environments such as those specified in Section 1.1, 1661 where the following assumptions hold: 1663 1. The Mapping System is secure and trusted, and for the purpose of 1664 this security considerations the Mapping System is considered as 1665 one trusted element. 1667 2. The ETRs have a pre-configured trust relationship with the 1668 Mapping System, which includes some form of shared keys, and the 1669 Mapping System is aware of which EIDs an ETR can advertise. How 1670 those keys and mappings gets established is out of the scope of 1671 this document. 1673 3. LISP-SEC [I-D.ietf-lisp-sec] MUST be implemented. Network 1674 operartors should carefully weight how the LISP-SEC threat model 1675 applies to their particular use case or deployment. If they 1676 decide to ignore a particular recommendation, they should make 1677 sure the risk associated with the corresponding threats is well 1678 understood. 1680 The Map-Request/Map-Reply message exchange can be exploited by an 1681 attacker to mount DoS and/or amplification attacks. Attackers can 1682 send Map-Requests at high rates to overload LISP nodes and increase 1683 the state maintained by such nodes or consume CPU cycles. Such 1684 threats can be mitigated by systematically applying filters and rate 1685 limiters. 1687 The 2-way LISP control-plane header nonce exchange can be used to 1688 avoid ITR spoofing attacks, but active on-path attackers (e.g 'man- 1689 in-the-middle') capable of intercepting the nonce can exploit the 1690 Map-Request/Map-Reply message exchange to inject forged mappings 1691 directly in the ITR EID-to-RLOC map-cache. In addition, valid ETRs 1692 in the system can perform overclaiming attacks. In this case, 1693 attackers can claim to own an EID-prefix that is larger than the 1694 prefix owned by the ETR. Such attacks can be addressed by using 1695 LISP-SEC [I-D.ietf-lisp-sec]. The LISP-SEC protocol defines a 1696 mechanism for providing origin authentication, integrity, anti- 1697 replay, protection, and prevention of 'man-in-the-middle' and 'prefix 1698 overclaiming' attacks on the Map-Request/Map-Reply exchange. In 1699 addition and while beyond the scope of securing an individual Map- 1700 Server or Map-Resolver, it should be noted that LISP-SEC can be 1701 complemented by additional security mechanisms defined by the Mapping 1702 System Infrastructure. For instance, BGP-based LISP-ALT [RFC6836] 1703 can take advantage of standards work on adding security to BGP while 1704 LISP-DDT [RFC8111] defines its own additional security mechanisms. 1706 To publish an authoritative EID-to-RLOC mapping with a Map-Server 1707 using the Map-Register message, an ETR includes authentication data 1708 that is a MAC of the entire message using a pair-wise shared key. An 1709 implementation MUST support use of HMAC-SHA-1-96 [RFC2104] and SHOULD 1710 support use of HMAC-SHA-256-128 [RFC6234] (SHA-256 truncated to 128 1711 bits). The Map-Register message is vulnerable to replay attacks by a 1712 man-in-the-middle. A compromised ETR can overclaim the prefix it 1713 owns and successfully register it on its corresponding Map-Server. 1714 To mitigate this and as noted in Section 8.2, a Map-Server SHOULD 1715 verify that all EID-Prefixes registered by an ETR match the 1716 configuration stored on the Map-Server. 1718 Deployments concerned about manipulations of Map-Request and Map- 1719 Reply messages, and malicious ETR EID prefix overclaiming MUST drop 1720 LISP Control Plane messages that do not contain LISP-SEC material 1721 (S-bit, EID-AD, OTK-AD, PKT-AD). 1723 Encrypting control messages via DTLS [RFC6347] or LISP-crypto 1724 [RFC8061] SHOULD be used to support privacy to prevent eavesdroping 1725 and packet tampering for messages exchanged between xTRs, xTRs and 1726 the mapping system, and nodes that make up the mapping system. 1728 A complete LISP threat analysis has been published in [RFC7835]. 1729 Please refer to it for more detailed security related details. 1731 10. Privacy Considerations 1733 As noted by [RFC6973] privacy is a complex issue that greatly depends 1734 on the specific protocol use-case and deployment. As noted in 1735 section 1.1 of [I-D.ietf-lisp-rfc6830bis] LISP focuses on use-cases 1736 where entities communicate over the public Internet while keeping 1737 separate addressing and topology. In what follows we detail the 1738 privacy threats introduced by the LISP Control Plane, the analysis is 1739 based on the guidelines detailed in [RFC6973]. 1741 LISP can use long-lived identifiers (EIDs) that survive mobility 1742 events. Such identifiers bind to the RLOCs of the nodes, which 1743 represents the topological location with respect to the specific LISP 1744 deployments. In addition, EID-to-RLOC mappings are typically 1745 considered public information within the LISP deployment when 1746 control-plane messages are not encrypted, and can be eavesdropped 1747 while Map-Request messages are sent to the corresponding Map- 1748 Resolvers or Map-Register messages to Map-Servers. 1750 In this context, attackers can correlate the EID with the RLOC and 1751 track the corresponding user topological location and/or mobility. 1752 This can be achieved by off-path attackers, if they are 1753 authenticated, by querying the mapping system. Deployments concerned 1754 about this threat can use access control-lists or stronger 1755 authentication mechanisms [I-D.ietf-lisp-ecdsa-auth] in the mapping 1756 system to make sure that only authorized users can access this 1757 information (data minimization). Use of ephemeral EIDs 1758 [I-D.ietf-lisp-eid-anonymity] to achieve anonymity is another 1759 mechanism to lessen persistency and identity tracking. 1761 11. Changes since RFC 6833 1763 For implementation considerations, the following changes have been 1764 made to this document since RFC 6833 was published: 1766 o A Map-Notify-Ack message is added in this document to provide 1767 reliability for Map-Notify messages. Any receiver of a Map-Notify 1768 message must respond with a Map-Notify-Ack message. Map-Servers 1769 who are senders of Map-Notify messages, must queue the Map-Notify 1770 contents until they receive a Map-Notify-Ack with the nonce used 1771 in the Map-Notify message. Note that implementations for Map- 1772 Notify-Ack support already exist and predate this document. 1774 o This document is incorporating the codepoint for the Map-Referral 1775 message from the LISP-DDT specification [RFC8111] to indicate that 1776 a Map-Server must send the final Map-Referral message when it 1777 participates in the LISP-DDT mapping system procedures. 1779 o The "m", "I", "L", and "D" bits are added to the Map-Request 1780 message. See Section 5.3 for details. 1782 o The "S", "I", "E", "T", "a", and "m" bits are added to the Map- 1783 Register message. See Section 5.6 for details. 1785 o The 16-bit Key-ID field of the Map-Register message has been split 1786 into a 8-bit Key-ID field and a 8-bit Algorithm-ID field. 1788 o This document adds two new Action values that are in an EID-record 1789 that appear in Map-Reply, Map-Register, Map-Notify, and Map- 1790 Notify-Ack messages. The Drop/Policy-Denied and Drop/Auth-Failure 1791 are the descriptions for the two new action values. See 1792 Section 5.4 for details. 1794 12. IANA Considerations 1796 This section provides guidance to the Internet Assigned Numbers 1797 Authority (IANA) regarding registration of values related to this 1798 LISP Control-Plane specification, in accordance with BCP 26 1799 [RFC8126]. 1801 There are three namespaces (listed in the sub-sections below) in LISP 1802 that have been registered. 1804 o LISP IANA registry allocations should not be made for purposes 1805 unrelated to LISP routing or transport protocols. 1807 o The following policies are used here with the meanings defined in 1808 BCP 26: "Specification Required", "IETF Review", "Experimental 1809 Use", and "First Come First Served". 1811 12.1. LISP UDP Port Numbers 1813 The IANA registry has allocated UDP port number 4342 for the LISP 1814 Control-Plane. IANA has updated the description for UDP port 4342 as 1815 follows: 1817 Keyword Port Transport Layer Description 1818 ------- ---- --------------- ----------- 1819 lisp-control 4342 udp LISP Control Packets 1821 12.2. LISP Packet Type Codes 1823 It is being requested that the IANA be authoritative for LISP Packet 1824 Type definitions and it is requested to replace the [RFC6830] 1825 registry message references with the RFC number assigned to this 1826 document. 1828 Based on deployment experience of [RFC6830], the Map-Notify-Ack 1829 message, message type 5, was added by this document. This document 1830 requests IANA to add it to the LISP Packet Type Registry. 1832 Name Number Defined in 1833 ---- ------ ----------- 1834 LISP Map-Notify-Ack 5 RFC6833bis 1836 12.3. LISP ACT and Flag Fields 1838 New ACT values can be allocated through IETF review or IESG approval. 1839 Four values have already been allocated by [RFC6830], IANA is 1840 requested to replace the [RFC6830] reference for this registry with 1841 the RFC number assigned to this document and the [RFC6830]. Action 1842 values references with the RFC number assigned to this document. 1843 This specification changes the name of ACT type 3 value from "Drop" 1844 to "Drop/No-Reason" as well as adding two new ACT values, the "Drop/ 1845 Policy-Denied" (type 4) and "Drop/Authentication-Failure" (type 5). 1847 Value Action Description Reference 1848 ----- ------ ----------- --------- 1849 4 Drop/ A Packet matching this Map-Cache RFC6833bis 1850 Policy-Denied entry is dropped because the target 1851 EID is policy-denied by the xTR or 1852 the mapping system. 1854 5 Drop/ A Packet matching this Map-Cache RFC6833bis 1855 Auth-Failure entry is dropped because the 1856 Map-Request for target EID fails an 1857 authentication check by the xTR or 1858 the mapping system. 1860 In addition, LISP has a number of flag fields and reserved fields, 1861 such as the LISP header flags field [I-D.ietf-lisp-rfc6830bis]. New 1862 bits for flags in these fields can be implemented after IETF review 1863 or IESG approval, but these need not be managed by IANA. 1865 12.4. LISP Address Type Codes 1867 LISP Canonical Address Format (LCAF) [RFC8060] is an 8-bit field that 1868 defines LISP-specific encodings for AFI value 16387. LCAF encodings 1869 are used for specific use-cases where different address types for 1870 EID-records and RLOC-records are required. 1872 The IANA registry "LISP Canonical Address Format (LCAF) Types" is 1873 used for LCAF types. The registry for LCAF types use the 1874 Specification Required policy [RFC8126]. Initial values for the 1875 registry as well as further information can be found in [RFC8060]. 1877 Therefore, there is no longer a need for the "LISP Address Type 1878 Codes" registry requested by [RFC6830]. This document requests to 1879 remove it. 1881 12.5. LISP Algorithm ID Numbers 1883 In [RFC6830], a request for a "LISP Key ID Numbers" registry was 1884 submitted. This document renames the registry to "LISP Algorithm ID 1885 Numbers" and requests the IANA to make the name change. 1887 The following Algorithm ID values are defined by this specification 1888 as used in any packet type that references a 'Algorithm ID' field: 1890 Name Number Defined in 1891 ----------------------------------------------- 1892 None 0 RFC6833bis 1893 HMAC-SHA-1-96 1 [RFC2404] 1894 HMAC-SHA-256-128 2 [RFC4868] 1896 Number values are in the range of 0 to 255. The allocation of values 1897 is on a first come first served basis. 1899 12.6. LISP Bit Flags 1901 This document asks IANA to create a registry for allocation of bits 1902 in several headers of the LISP control plane, namely in the Map- 1903 Request, Map-Reply, Map-Register, Encapsulated Control Message (ECM) 1904 messages. Bit allocations are also requested for EID-records and 1905 RLOC-records. The registry created should be named "LISP Control 1906 Plane Header Bits". A sub-registry needs to be created per each 1907 message and record. The name of each sub-registry is indicated 1908 below, along with its format and allocation of bits defined in this 1909 document. Any additional bits allocation, requires a specification, 1910 according with [RFC5226] policies. 1912 Sub-Registry: Map-Request Header Bits [Section 5.2]: 1914 0 1 2 3 1915 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 1916 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1917 |Type=1 |A|M|P|S|p|s|R|R| Rsvd |L|D| IRC | Record Count | 1918 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1920 +----------+---------------+------------+---------------------------+ 1921 | Spec | IANA Name | Bit | Description | 1922 | Name | | Position | | 1923 +----------+---------------+------------+---------------------------+ 1924 | A | map-request-A | 4 | Authoritative Bit | 1925 | M | map-request-M | 5 | Map Data Present Bit | 1926 | P | map-request-P | 6 | RLOC-Probe Request Bit | 1927 | S | map-request-S | 7 | Solicit Map-Request (SMR) | 1928 | | | | Bit | 1929 | p | map-request-p | 8 | Proxy-ITR Bit | 1930 | s | map-request-s | 9 | Solicit Map-Request | 1931 | | | | Invoked Bit | 1932 | L | map-request-L | 17 | Local xTR Bit | 1933 | D | map-request-D | 18 | Don't Map-Reply Bit | 1934 +----------+---------------+------------+---------------------------+ 1936 LISP Map-Request Header Bits 1938 Sub-Registry: Map-Reply Header Bits [Section 5.4]: 1940 0 1 2 3 1941 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 1942 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1943 |Type=2 |P|E|S| Reserved | Record Count | 1944 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1946 +-----------+-------------+--------------+------------------------+ 1947 | Spec Name | IANA Name | Bit Position | Description | 1948 +-----------+-------------+--------------+------------------------+ 1949 | P | map-reply-P | 4 | RLOC-Probe Bit | 1950 | E | map-reply-E | 5 | Echo Nonce Capable Bit | 1951 | S | map-reply-S | 6 | Security Bit | 1952 +-----------+-------------+--------------+------------------------+ 1954 LISP Map-Reply Header Bits 1956 Sub-Registry: Map-Register Header Bits [Section 5.6]: 1958 0 1 2 3 1959 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 1960 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1961 |Type=3 |P|S|I| Reserved |E|T|a|R|M| Record Count | 1962 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1964 +-----------+----------------+--------------+----------------------+ 1965 | Spec Name | IANA Name | Bit Position | Description | 1966 +-----------+----------------+--------------+----------------------+ 1967 | P | map-register-P | 4 | Proxy Map-Reply Bit | 1968 | S | map-register-S | 5 | LISP-SEC Capable Bit | 1969 | I | map-register-I | 6 | xTR-ID present flag | 1970 +-----------+----------------+--------------+----------------------+ 1972 LISP Map-Register Header Bits 1974 Sub-Registry: Encapsulated Control Message (ECM) Header Bits 1975 [Section 5.8]: 1977 0 1 2 3 1978 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 1979 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1980 |Type=8 |S|D|E|M| Reserved | 1981 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1982 +-----------+-----------+--------------+----------------------------+ 1983 | Spec Name | IANA Name | Bit Position | Description | 1984 +-----------+-----------+--------------+----------------------------+ 1985 | S | ecm-S | 4 | Security Bit | 1986 | D | ecm-D | 5 | LISP-DDT Bit | 1987 | E | ecm-E | 6 | Forward to ETR Bit | 1988 | M | ecm-M | 7 | Destined to Map-Server Bit | 1989 +-----------+-----------+--------------+----------------------------+ 1991 LISP Encapsulated Control Message (ECM) Header Bits 1993 Sub-Registry: EID-Record Header Bits [Section 5.4]: 1995 0 1 2 3 1996 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 1997 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1998 | Locator Count | EID mask-len | ACT |A| Reserved | 1999 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2001 +-----------+--------------+--------------+-------------------+ 2002 | Spec Name | IANA Name | Bit Position | Description | 2003 +-----------+--------------+--------------+-------------------+ 2004 | A | eid-record-A | 19 | Authoritative Bit | 2005 +-----------+--------------+--------------+-------------------+ 2007 LISP EID-Record Header Bits 2009 Sub-Registry: RLOC-Record Header Bits [Section 5.4]: 2011 0 1 2 3 2012 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 2013 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2014 | Unused Flags |L|p|R| Loc-AFI | 2015 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2017 +-----------+---------------+--------------+----------------------+ 2018 | Spec Name | IANA Name | Bit Position | Description | 2019 +-----------+---------------+--------------+----------------------+ 2020 | L | rloc-record-L | 13 | Local RLOC Bit | 2021 | p | rloc-record-p | 19 | RLOC-Probe Reply Bit | 2022 | R | rloc-record-R | 19 | RLOC Reachable Bit | 2023 +-----------+---------------+--------------+----------------------+ 2025 LISP RLOC-Record Header Bits 2027 13. References 2029 13.1. Normative References 2031 [I-D.ietf-lisp-6834bis] 2032 Iannone, L., Saucez, D., and O. Bonaventure, "Locator/ID 2033 Separation Protocol (LISP) Map-Versioning", draft-ietf- 2034 lisp-6834bis-02 (work in progress), September 2018. 2036 [I-D.ietf-lisp-rfc6830bis] 2037 Farinacci, D., Fuller, V., Meyer, D., Lewis, D., and A. 2038 Cabellos-Aparicio, "The Locator/ID Separation Protocol 2039 (LISP)", draft-ietf-lisp-rfc6830bis-26 (work in progress), 2040 November 2018. 2042 [I-D.ietf-lisp-sec] 2043 Maino, F., Ermagan, V., Cabellos-Aparicio, A., and D. 2044 Saucez, "LISP-Security (LISP-SEC)", draft-ietf-lisp-sec-17 2045 (work in progress), November 2018. 2047 [RFC2404] Madson, C. and R. Glenn, "The Use of HMAC-SHA-1-96 within 2048 ESP and AH", RFC 2404, DOI 10.17487/RFC2404, November 2049 1998, . 2051 [RFC4086] Eastlake 3rd, D., Schiller, J., and S. Crocker, 2052 "Randomness Requirements for Security", BCP 106, RFC 4086, 2053 DOI 10.17487/RFC4086, June 2005, 2054 . 2056 [RFC4868] Kelly, S. and S. Frankel, "Using HMAC-SHA-256, HMAC-SHA- 2057 384, and HMAC-SHA-512 with IPsec", RFC 4868, 2058 DOI 10.17487/RFC4868, May 2007, 2059 . 2061 [RFC4984] Meyer, D., Ed., Zhang, L., Ed., and K. Fall, Ed., "Report 2062 from the IAB Workshop on Routing and Addressing", 2063 RFC 4984, DOI 10.17487/RFC4984, September 2007, 2064 . 2066 [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an 2067 IANA Considerations Section in RFCs", RFC 5226, 2068 DOI 10.17487/RFC5226, May 2008, 2069 . 2071 [RFC6071] Frankel, S. and S. Krishnan, "IP Security (IPsec) and 2072 Internet Key Exchange (IKE) Document Roadmap", RFC 6071, 2073 DOI 10.17487/RFC6071, February 2011, 2074 . 2076 [RFC6347] Rescorla, E. and N. Modadugu, "Datagram Transport Layer 2077 Security Version 1.2", RFC 6347, DOI 10.17487/RFC6347, 2078 January 2012, . 2080 [RFC8085] Eggert, L., Fairhurst, G., and G. Shepherd, "UDP Usage 2081 Guidelines", BCP 145, RFC 8085, DOI 10.17487/RFC8085, 2082 March 2017, . 2084 13.2. Informative References 2086 [AFI] IANA, "Address Family Identifier (AFIs)", ADDRESS FAMILY 2087 NUMBERS http://www.iana.org/assignments/address-family- 2088 numbers/address-family-numbers.xhtml?, Febuary 2007. 2090 [GTP-3GPP] 2091 3GPP, "General Packet Radio System (GPRS) Tunnelling 2092 Protocol User Plane (GTPv1-U)", TS.29.281 2093 https://portal.3gpp.org/desktopmodules/Specifications/ 2094 SpecificationDetails.aspx?specificationId=1699, January 2095 2015. 2097 [I-D.herbert-intarea-ila] 2098 Herbert, T. and P. Lapukhov, "Identifier-locator 2099 addressing for IPv6", draft-herbert-intarea-ila-01 (work 2100 in progress), March 2018. 2102 [I-D.ietf-lisp-ecdsa-auth] 2103 Farinacci, D. and E. Nordmark, "LISP Control-Plane ECDSA 2104 Authentication and Authorization", draft-ietf-lisp-ecdsa- 2105 auth-00 (work in progress), September 2018. 2107 [I-D.ietf-lisp-eid-anonymity] 2108 Farinacci, D., Pillay-Esnault, P., and W. Haddad, "LISP 2109 EID Anonymity", draft-ietf-lisp-eid-anonymity-04 (work in 2110 progress), October 2018. 2112 [I-D.ietf-lisp-eid-mobility] 2113 Portoles-Comeras, M., Ashtaputre, V., Moreno, V., Maino, 2114 F., and D. Farinacci, "LISP L2/L3 EID Mobility Using a 2115 Unified Control Plane", draft-ietf-lisp-eid-mobility-03 2116 (work in progress), November 2018. 2118 [I-D.ietf-lisp-gpe] 2119 Maino, F., Lemon, J., Agarwal, P., Lewis, D., and M. 2120 Smith, "LISP Generic Protocol Extension", draft-ietf-lisp- 2121 gpe-06 (work in progress), September 2018. 2123 [I-D.ietf-lisp-introduction] 2124 Cabellos-Aparicio, A. and D. Saucez, "An Architectural 2125 Introduction to the Locator/ID Separation Protocol 2126 (LISP)", draft-ietf-lisp-introduction-13 (work in 2127 progress), April 2015. 2129 [I-D.ietf-lisp-mn] 2130 Farinacci, D., Lewis, D., Meyer, D., and C. White, "LISP 2131 Mobile Node", draft-ietf-lisp-mn-04 (work in progress), 2132 October 2018. 2134 [I-D.ietf-lisp-pubsub] 2135 Rodriguez-Natal, A., Ermagan, V., Leong, J., Maino, F., 2136 Cabellos-Aparicio, A., Barkai, S., Farinacci, D., 2137 Boucadair, M., Jacquenet, C., and S. Secci, "Publish/ 2138 Subscribe Functionality for LISP", draft-ietf-lisp- 2139 pubsub-02 (work in progress), November 2018. 2141 [I-D.ietf-nvo3-vxlan-gpe] 2142 Maino, F., Kreeger, L., and U. Elzur, "Generic Protocol 2143 Extension for VXLAN", draft-ietf-nvo3-vxlan-gpe-06 (work 2144 in progress), April 2018. 2146 [I-D.ietf-opsec-icmp-filtering] 2147 Gont, F., Gont, G., and C. Pignataro, "Recommendations for 2148 filtering ICMP messages", draft-ietf-opsec-icmp- 2149 filtering-04 (work in progress), July 2013. 2151 [I-D.meyer-loc-id-implications] 2152 Meyer, D. and D. Lewis, "Architectural Implications of 2153 Locator/ID Separation", draft-meyer-loc-id-implications-01 2154 (work in progress), January 2009. 2156 [RFC1035] Mockapetris, P., "Domain names - implementation and 2157 specification", STD 13, RFC 1035, DOI 10.17487/RFC1035, 2158 November 1987, . 2160 [RFC1071] Braden, R., Borman, D., and C. Partridge, "Computing the 2161 Internet checksum", RFC 1071, DOI 10.17487/RFC1071, 2162 September 1988, . 2164 [RFC2104] Krawczyk, H., Bellare, M., and R. Canetti, "HMAC: Keyed- 2165 Hashing for Message Authentication", RFC 2104, 2166 DOI 10.17487/RFC2104, February 1997, 2167 . 2169 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 2170 Requirement Levels", BCP 14, RFC 2119, 2171 DOI 10.17487/RFC2119, March 1997, 2172 . 2174 [RFC2890] Dommety, G., "Key and Sequence Number Extensions to GRE", 2175 RFC 2890, DOI 10.17487/RFC2890, September 2000, 2176 . 2178 [RFC6234] Eastlake 3rd, D. and T. Hansen, "US Secure Hash Algorithms 2179 (SHA and SHA-based HMAC and HKDF)", RFC 6234, 2180 DOI 10.17487/RFC6234, May 2011, 2181 . 2183 [RFC6830] Farinacci, D., Fuller, V., Meyer, D., and D. Lewis, "The 2184 Locator/ID Separation Protocol (LISP)", RFC 6830, 2185 DOI 10.17487/RFC6830, January 2013, 2186 . 2188 [RFC6831] Farinacci, D., Meyer, D., Zwiebel, J., and S. Venaas, "The 2189 Locator/ID Separation Protocol (LISP) for Multicast 2190 Environments", RFC 6831, DOI 10.17487/RFC6831, January 2191 2013, . 2193 [RFC6832] Lewis, D., Meyer, D., Farinacci, D., and V. Fuller, 2194 "Interworking between Locator/ID Separation Protocol 2195 (LISP) and Non-LISP Sites", RFC 6832, 2196 DOI 10.17487/RFC6832, January 2013, 2197 . 2199 [RFC6836] Fuller, V., Farinacci, D., Meyer, D., and D. Lewis, 2200 "Locator/ID Separation Protocol Alternative Logical 2201 Topology (LISP+ALT)", RFC 6836, DOI 10.17487/RFC6836, 2202 January 2013, . 2204 [RFC6837] Lear, E., "NERD: A Not-so-novel Endpoint ID (EID) to 2205 Routing Locator (RLOC) Database", RFC 6837, 2206 DOI 10.17487/RFC6837, January 2013, 2207 . 2209 [RFC6973] Cooper, A., Tschofenig, H., Aboba, B., Peterson, J., 2210 Morris, J., Hansen, M., and R. Smith, "Privacy 2211 Considerations for Internet Protocols", RFC 6973, 2212 DOI 10.17487/RFC6973, July 2013, 2213 . 2215 [RFC7348] Mahalingam, M., Dutt, D., Duda, K., Agarwal, P., Kreeger, 2216 L., Sridhar, T., Bursell, M., and C. Wright, "Virtual 2217 eXtensible Local Area Network (VXLAN): A Framework for 2218 Overlaying Virtualized Layer 2 Networks over Layer 3 2219 Networks", RFC 7348, DOI 10.17487/RFC7348, August 2014, 2220 . 2222 [RFC7835] Saucez, D., Iannone, L., and O. Bonaventure, "Locator/ID 2223 Separation Protocol (LISP) Threat Analysis", RFC 7835, 2224 DOI 10.17487/RFC7835, April 2016, 2225 . 2227 [RFC8060] Farinacci, D., Meyer, D., and J. Snijders, "LISP Canonical 2228 Address Format (LCAF)", RFC 8060, DOI 10.17487/RFC8060, 2229 February 2017, . 2231 [RFC8061] Farinacci, D. and B. Weis, "Locator/ID Separation Protocol 2232 (LISP) Data-Plane Confidentiality", RFC 8061, 2233 DOI 10.17487/RFC8061, February 2017, 2234 . 2236 [RFC8111] Fuller, V., Lewis, D., Ermagan, V., Jain, A., and A. 2237 Smirnov, "Locator/ID Separation Protocol Delegated 2238 Database Tree (LISP-DDT)", RFC 8111, DOI 10.17487/RFC8111, 2239 May 2017, . 2241 [RFC8113] Boucadair, M. and C. Jacquenet, "Locator/ID Separation 2242 Protocol (LISP): Shared Extension Message & IANA Registry 2243 for Packet Type Allocations", RFC 8113, 2244 DOI 10.17487/RFC8113, March 2017, 2245 . 2247 [RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for 2248 Writing an IANA Considerations Section in RFCs", BCP 26, 2249 RFC 8126, DOI 10.17487/RFC8126, June 2017, 2250 . 2252 [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2253 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, 2254 May 2017, . 2256 [RFC8378] Moreno, V. and D. Farinacci, "Signal-Free Locator/ID 2257 Separation Protocol (LISP) Multicast", RFC 8378, 2258 DOI 10.17487/RFC8378, May 2018, 2259 . 2261 [RFC8402] Filsfils, C., Ed., Previdi, S., Ed., Ginsberg, L., 2262 Decraene, B., Litkowski, S., and R. Shakir, "Segment 2263 Routing Architecture", RFC 8402, DOI 10.17487/RFC8402, 2264 July 2018, . 2266 Appendix A. Acknowledgments 2268 The original authors would like to thank Greg Schudel, Darrel Lewis, 2269 John Zwiebel, Andrew Partan, Dave Meyer, Isidor Kouvelas, Jesper 2270 Skriver, Fabio Maino, and members of the lisp@ietf.org mailing list 2271 for their feedback and helpful suggestions. 2273 Special thanks are due to Noel Chiappa for his extensive work and 2274 thought about caching in Map-Resolvers. 2276 The current authors would like to give a sincere thank you to the 2277 people who help put LISP on standards track in the IETF. They 2278 include Joel Halpern, Luigi Iannone, Deborah Brungard, Fabio Maino, 2279 Scott Bradner, Kyle Rose, Takeshi Takahashi, Sarah Banks, Pete 2280 Resnick, Colin Perkins, Mirja Kuhlewind, Francis Dupont, Benjamin 2281 Kaduk, Eric Rescorla, Alvaro Retana, Alexey Melnikov, Alissa Cooper, 2282 Suresh Krishnan, Alberto Rodriguez-Natal, Vina Ermagen, Mohamed 2283 Boucadair, Brian Trammell, Sabrina Tanamal, and John Drake. The 2284 contributions they offered greatly added to the security, scale, and 2285 robustness of the LISP architecture and protocols. 2287 Appendix B. Document Change Log 2289 [RFC Editor: Please delete this section on publication as RFC.] 2291 B.1. Changes to draft-ietf-lisp-rfc6833bis-23 2293 o Posted December 2018. 2295 o Added to Security Considerations section that deployments that 2296 care about prefix over claiming should use LISP-SEC. 2298 o Added to Security Considerations section that DTLS or LISP-crypto 2299 be used for control-plane privacy. 2301 o Make LISP-SEC a normative reference. 2303 o Make it more clear where field descriptions are spec'ed when 2304 referencing to the same fields in other packet types. 2306 B.2. Changes to draft-ietf-lisp-rfc6833bis-22 2308 o Posted week after IETF November 2018. 2310 o No longer need to use IPSEC for replay attacks. 2312 B.3. Changes to draft-ietf-lisp-rfc6833bis-21 2314 o Posted early November 2018. 2316 o Added I-bit back in because its necessary to use for Map-Register 2317 replay attack scenarios. The Map-Server tracks the nonce per xTR- 2318 ID to detect duplicate or replayed Map-Register messages. 2320 B.4. Changes to draft-ietf-lisp-rfc6833bis-20 2322 o Posted late October 2018. 2324 o Changed description about "reserved" bits to state "reserved and 2325 unassigned". 2327 o Make it more clear how Map-Register nonce processing is performed 2328 in an ETR and Map-Server. 2330 B.5. Changes to draft-ietf-lisp-rfc6833bis-19 2332 o Posted mid October 2018. 2334 o Added Fabio text to the Security Considerations section. 2336 B.6. Changes to draft-ietf-lisp-rfc6833bis-18 2338 o Posted mid October 2018. 2340 o Fixed comments from Eric after more email clarity. 2342 B.7. Changes to draft-ietf-lisp-rfc6833bis-17 2344 o Posted early October 2018. 2346 o Changes to reflect comments from Sep 27th Telechat. 2348 o Added all flag bit definitions as request for allocation in IANA 2349 Considersations section. 2351 o Added an applicability statement in section 1 to address security 2352 concerns from Telechat. 2354 o Moved m-bit description and IANA request to draft-ietf-lisp-mn. 2356 o Moved I-bit description and IANA request to draft-ietf-lisp- 2357 pubsub. 2359 B.8. Changes to draft-ietf-lisp-rfc6833bis-16 2361 o Posted Late-September 2018. 2363 o Re-wrote Security Considerations section. Thanks Albert. 2365 o Added Alvaro text to be more clear about IANA actions. 2367 B.9. Changes to draft-ietf-lisp-rfc6833bis-15 2369 o Posted mid-September 2018. 2371 o Changes to reflect comments from Colin and Mirja. 2373 B.10. Changes to draft-ietf-lisp-rfc6833bis-14 2375 o Posted September 2018. 2377 o Changes to reflect comments from Genart, RTGarea, and Secdir 2378 reviews. 2380 B.11. Changes to draft-ietf-lisp-rfc6833bis-13 2382 o Posted August 2018. 2384 o Final editorial changes before RFC submission for Proposed 2385 Standard. 2387 o Added section "Changes since RFC 6833" so implementators are 2388 informed of any changes since the last RFC publication. 2390 B.12. Changes to draft-ietf-lisp-rfc6833bis-12 2392 o Posted late July 2018. 2394 o Moved RFC6830bis and RFC6834bis to Normative References. 2396 B.13. Changes to draft-ietf-lisp-rfc6833bis-11 2398 o Posted July 2018. 2400 o Fixed Luigi editorial comments to ready draft for RFC status and 2401 ran through IDNITs again. 2403 B.14. Changes to draft-ietf-lisp-rfc6833bis-10 2405 o Posted after LISP WG at IETF week March. 2407 o Move AD field encoding after S-bit in the ECM packet format 2408 description section. 2410 o Say more about when the new Drop actions should be sent. 2412 B.15. Changes to draft-ietf-lisp-rfc6833bis-09 2414 o Posted March IETF week 2018. 2416 o Fixed editorial comments submitted by document shepherd Luigi 2417 Iannone. 2419 B.16. Changes to draft-ietf-lisp-rfc6833bis-08 2421 o Posted March 2018. 2423 o Added RLOC-probing algorithm. 2425 o Added Solicit-Map Request algorithm. 2427 o Added several mechanisms (from 6830bis) regarding Routing Locator 2428 Reachability. 2430 o Added port 4342 to IANA Considerations section. 2432 B.17. Changes to draft-ietf-lisp-rfc6833bis-07 2434 o Posted December 2017. 2436 o Make it more clear in a couple of places that RLOCs are used to 2437 locate ETRs more so than for Map-Server Map-Request forwarding. 2439 o Make it clear that "encapsualted" for a control message is an ECM 2440 based message. 2442 o Make it more clear what messages use source-port 4342 and which 2443 ones use destinatino-port 4342. 2445 o Don't make DDT references when the mapping transport system can be 2446 of any type and the referneced text is general to it. 2448 o Generalize text when referring to the format of an EID-prefix. 2449 Can use othe AFIs then IPv4 and IPv6. 2451 o Many editorial changes to clarify text. 2453 o Changed some "must", "should", and "may" to capitalized. 2455 o Added definitions for Map-Request and Map-Reply messages. 2457 o Ran document through IDNITs. 2459 B.18. Changes to draft-ietf-lisp-rfc6833bis-06 2461 o Posted October 2017. 2463 o Spec the I-bit to include the xTR-ID in a Map-Request message to 2464 be consistent with the Map-Register message and to anticipate the 2465 introduction of pubsub functionality to allow Map-Requests to 2466 subscribe to RLOC-set changes. 2468 o Updated references for individual submissions that became working 2469 group documents. 2471 o Updated references for working group documents that became RFCs. 2473 B.19. Changes to draft-ietf-lisp-rfc6833bis-05 2475 o Posted May 2017. 2477 o Update IANA Considerations section based on new requests from this 2478 document and changes from what was requested in [RFC6830]. 2480 B.20. Changes to draft-ietf-lisp-rfc6833bis-04 2482 o Posted May 2017. 2484 o Clarify how the Key-ID field is used in Map-Register and Map- 2485 Notify messages. Break the 16-bit field into a 8-bit Key-ID field 2486 and a 8-bit Algorithm-ID field. 2488 o Move the Control-Plane codepoints from the IANA Considerations 2489 section of RFC6830bis to the IANA Considerations section of this 2490 document. 2492 o In the "LISP Control Packet Type Allocations" section, indicate 2493 how message Types are IANA allocated and how experimental RFC8113 2494 sub-types should be requested. 2496 B.21. Changes to draft-ietf-lisp-rfc6833bis-03 2498 o Posted April 2017. 2500 o Add types 9-14 and specify they are not assigned. 2502 o Add the "LISP Shared Extension Message" type and point to RFC8113. 2504 B.22. Changes to draft-ietf-lisp-rfc6833bis-02 2506 o Posted April 2017. 2508 o Clarify that the LISP Control-Plane document defines how the LISP 2509 Data-Plane uses Map-Requests with either the SMR-bit set or the 2510 P-bit set supporting mapping updates and RLOC-probing. Indicating 2511 that other Data-Planes can use the same mechanisms or their own 2512 defined mechanisms to achieve the same functionality. 2514 B.23. Changes to draft-ietf-lisp-rfc6833bis-01 2516 o Posted March 2017. 2518 o Include references to new RFCs published. 2520 o Remove references to self. 2522 o Change references from RFC6830 to RFC6830bis. 2524 o Add two new action/reasons to a Map-Reply has posted to the LISP 2525 WG mailing list. 2527 o In intro section, add refernece to I-D.ietf-lisp-introduction. 2529 o Removed Open Issues section and references to "experimental". 2531 B.24. Changes to draft-ietf-lisp-rfc6833bis-00 2533 o Posted December 2016. 2535 o Created working group document from draft-farinacci-lisp 2536 -rfc6833-00 individual submission. No other changes made. 2538 B.25. Changes to draft-farinacci-lisp-rfc6833bis-00 2540 o Posted November 2016. 2542 o This is the initial draft to turn RFC 6833 into RFC 6833bis. 2544 o The document name has changed from the "Locator/ID Separation 2545 Protocol (LISP) Map-Server Interface" to the "Locator/ID 2546 Separation Protocol (LISP) Control-Plane". 2548 o The fundamental change was to move the Control-Plane messages from 2549 RFC 6830 to this document in an effort so any IETF developed or 2550 industry created Data-Plane could use the LISP mapping system and 2551 Control-Plane. 2553 o Update Control-Plane messages to incorporate what has been 2554 implemented in products during the early phase of LISP development 2555 but wasn't able to make it into RFC6830 and RFC6833 to make the 2556 Experimental RFC deadline. 2558 o Indicate there may be nodes in the mapping system that are not MRs 2559 or MSs, that is a ALT-node or a DDT-node. 2561 o Include LISP-DDT in Map-Resolver section and explain how they 2562 maintain a referral-cache. 2564 o Removed open issue about additional state in Map-Servers. With 2565 [RFC8111], Map-Servers have the same registration state and can 2566 give Map-Resolvers complete information in ms-ack Map-Referral 2567 messages. 2569 o Make reference to the LISP Threats Analysis RFC [RFC7835]. 2571 Authors' Addresses 2573 Vince Fuller 2574 Cisco Systems 2576 EMail: vaf@vaf.net 2578 Dino Farinacci 2579 Cisco Systems 2581 EMail: farinacci@gmail.com 2583 Albert Cabellos 2584 UPC/BarcelonaTech 2585 Campus Nord, C. Jordi Girona 1-3 2586 Barcelona, Catalunya 2587 Spain 2589 EMail: acabello@ac.upc.edu