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Checking references for intended status: Informational ---------------------------------------------------------------------------- == Outdated reference: A later version (-24) exists of draft-ietf-lisp-22 ** Obsolete normative reference: RFC 5226 (Obsoleted by RFC 8126) Summary: 1 error (**), 0 flaws (~~), 2 warnings (==), 1 comment (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Network Working Group L. Iannone 3 Internet-Draft Telecom ParisTech 4 Intended status: Informational D. Lewis 5 Expires: October 26, 2012 D. Meyer 6 V. Fuller 7 Cisco Systems, Inc. 8 April 24, 2012 10 LISP EID Block 11 draft-ietf-lisp-eid-block-02.txt 13 Abstract 15 This is a direction to IANA to allocate a /16 IPv6 prefix for use 16 with the Locator/ID Separation Protocol (LISP). The prefix will be 17 used for local intra-domain routing and global endpoint 18 identification, by sites deploying LISP as EID (Endpoint IDentifier) 19 addressing space. 21 Status of this Memo 23 This Internet-Draft is submitted in full conformance with the 24 provisions of BCP 78 and BCP 79. 26 Internet-Drafts are working documents of the Internet Engineering 27 Task Force (IETF). Note that other groups may also distribute 28 working documents as Internet-Drafts. The list of current Internet- 29 Drafts is at http://datatracker.ietf.org/drafts/current/. 31 Internet-Drafts are draft documents valid for a maximum of six months 32 and may be updated, replaced, or obsoleted by other documents at any 33 time. It is inappropriate to use Internet-Drafts as reference 34 material or to cite them other than as "work in progress." 36 This Internet-Draft will expire on October 26, 2012. 38 Copyright Notice 40 Copyright (c) 2012 IETF Trust and the persons identified as the 41 document authors. All rights reserved. 43 This document is subject to BCP 78 and the IETF Trust's Legal 44 Provisions Relating to IETF Documents 45 (http://trustee.ietf.org/license-info) in effect on the date of 46 publication of this document. Please review these documents 47 carefully, as they describe your rights and restrictions with respect 48 to this document. Code Components extracted from this document must 49 include Simplified BSD License text as described in Section 4.e of 50 the Trust Legal Provisions and are provided without warranty as 51 described in the Simplified BSD License. 53 Table of Contents 55 1. Requirements Notation . . . . . . . . . . . . . . . . . . . . . 3 56 2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 57 3. Definition of Terms . . . . . . . . . . . . . . . . . . . . . . 3 58 4. Rationale and Intent . . . . . . . . . . . . . . . . . . . . . 5 59 5. Expected use . . . . . . . . . . . . . . . . . . . . . . . . . 6 60 6. Block Dimension . . . . . . . . . . . . . . . . . . . . . . . . 6 61 7. Action Plan . . . . . . . . . . . . . . . . . . . . . . . . . . 7 62 8. Routing Considerations . . . . . . . . . . . . . . . . . . . . 7 63 9. Security Considerations . . . . . . . . . . . . . . . . . . . . 7 64 10. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . 8 65 11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 8 66 12. References . . . . . . . . . . . . . . . . . . . . . . . . . . 8 67 12.1. Normative References . . . . . . . . . . . . . . . . . . . 8 68 12.2. Informative References . . . . . . . . . . . . . . . . . . 9 69 Appendix A. Document Change Log . . . . . . . . . . . . . . . . . 9 70 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 9 72 1. Requirements Notation 74 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 75 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 76 document are to be interpreted as described in [RFC2119]. 78 2. Introduction 80 This document directs the IANA to allocate a /16 IPv6 prefix for use 81 with the Locator/ID Separation Protocol (LISP - [I-D.ietf-lisp]), 82 LISP Map Server ([I-D.ietf-lisp-ms]), LISP Alternative Topology 83 (LISP+ALT - [I-D.ietf-lisp-alt]) (or other) mapping system, and LISP 84 Interworking ([I-D.ietf-lisp-interworking]). 86 This block will be used as global Endpoint IDentifier (EID) space 87 (Section 3). 89 3. Definition of Terms 91 LISP operates on two name spaces and introduces several new network 92 elements. This section provides high-level definitions of the LISP 93 name spaces and network elements and as such, it MUST NOT be 94 considered as an authoritative source. The reference to the 95 authoritative document for each term is included in every term 96 description. 98 Legacy Internet: The portion of the Internet that does not run LISP 99 and does not participate in LISP+ALT or any other mapping system. 101 LISP site: A LISP site is a set of routers in an edge network that 102 are under a single technical administration. LISP routers that 103 reside in the edge network are the demarcation points to separate 104 the edge network from the core network. See [I-D.ietf-lisp] for 105 more details. 107 Endpoint ID (EID): An EID is a 32-bit (for IPv4) or 128-bit (for 108 IPv6) value used in the source and destination address fields of 109 the first (most inner) LISP header of a packet. A packet that is 110 emitted by a system contains EIDs in its headers and LISP headers 111 are prepended only when the packet reaches an Ingress Tunnel 112 Router (ITR) on the data path to the destination EID. The source 113 EID is obtained via existing mechanisms used to set a host's 114 "local" IP address. An EID is allocated to a host from an EID- 115 prefix block associated with the site where the host is located. 116 See [I-D.ietf-lisp] for more details. 118 EID-prefix: A power-of-two block of EIDs that are allocated to a 119 site by an address allocation authority. See [I-D.ietf-lisp] for 120 more details. 122 EID-Prefix Aggregate: A set of EID-prefixes said to be aggregatable 123 in the [RFC4632] sense. That is, an EID-Prefix aggregate is 124 defined to be a single contiguous power-of-two EID-prefix block. 125 A prefix and a length characterize such a block. See 126 [I-D.ietf-lisp] for more details. 128 Routing LOCator (RLOC): A RLOC is an IPv4 or IPv6 address of an 129 egress tunnel router (ETR). A RLOC is the output of an EID-to- 130 RLOC mapping lookup. An EID maps to one or more RLOCs. 131 Typically, RLOCs are numbered from topologically aggregatable 132 blocks that are assigned to a site at each point to which it 133 attaches to the global Internet; where the topology is defined by 134 the connectivity of provider networks, RLOCs can be thought of as 135 Provider Aggregatable (PA) addresses. See [I-D.ietf-lisp] for 136 more details. 138 EID-to-RLOC Mapping: A binding between an EID-Prefix and the RLOC- 139 set that can be used to reach the EID-Prefix. The general term 140 "mapping" always refers to an EID-to-RLOC mapping. See 141 [I-D.ietf-lisp] for more details. 143 Ingress Tunnel Router (ITR): An Ingress Tunnel Router (ITR) is a 144 router that accepts receives IP packets from site end-systems on 145 one side and sends LISP-encapsulated IP packets toward the 146 Internet on the other side. The router treats the "inner" IP 147 destination address as an EID and performs an EID-to-RLOC mapping 148 lookup. The router then prepends an "outer" IP header with one of 149 its globally routable RLOCs in the source address field and the 150 result of the mapping lookup in the destination address field. 151 See [I-D.ietf-lisp] for more details. 153 Egress Tunnel Router (ETR): An Egress Tunnel Router (ETR) receives 154 LISP-encapsulated IP packets from the Internet on one side and 155 sends decapsulated IP packets to site end-systems on the other 156 side. An ETR router accepts an IP packet where the destination 157 address in the "outer" IP header is one of its own RLOCs. The 158 router strips the "outer" header and forwards the packet based on 159 the next IP header found. See [I-D.ietf-lisp] for more details. 161 Proxy ITR (PITR): A Proxy-ITR (PITR) acts like an ITR but does so on 162 behalf of non-LISP sites which send packets to destinations at 163 LISP sites. See [I-D.ietf-lisp-interworking] for more details. 165 Proxy ETR (PETR): A Proxy-ETR (PETR) acts like an ETR but does so on 166 behalf of LISP sites which send packets to destinations at non- 167 LISP sites. See [I-D.ietf-lisp-interworking] for more details. 169 Map Server (MS): A network infrastructure component that learns EID- 170 to-RLOC mapping entries from an authoritative source (typically an 171 ETR). A Map-Server publishes these mappings in the distributed 172 mapping system. See [I-D.ietf-lisp-ms] for more details. 174 Map Resolver (MR): A network infrastructure component that accepts 175 LISP Encapsulated Map-Requests, typically from an ITR, quickly 176 determines whether or not the destination IP address is part of 177 the EID namespace; if it is not, a Negative Map-Reply is 178 immediately returned. Otherwise, the Map-Resolver finds the 179 appropriate EID-to-RLOC mapping by consulting the distributed 180 mapping database system. See [I-D.ietf-lisp-ms] for more details. 182 The LISP Alternative Logical Topology (ALT): The virtual overlay 183 network made up of tunnels between LISP+ALT Routers. The Border 184 Gateway Protocol (BGP) runs between ALT Routers and is used to 185 carry reachability information for EID-prefixes. The ALT provides 186 a way to forward Map-Requests toward the ETR that "owns" an EID- 187 prefix. See [I-D.ietf-lisp-alt] for more details. 189 ALT Router: The device on which runs the ALT. The ALT is a static 190 network built using tunnels between ALT Routers. These routers 191 are deployed in a roughly-hierarchical mesh in which routers at 192 each level in the topology are responsible for aggregating EID- 193 Prefixes learned from those logically "below" them and advertising 194 summary prefixes to those logically "above" them. Prefix learning 195 and propagation between ALT Routers is done using BGP. When an 196 ALT Router receives an ALT Datagram, it looks up the destination 197 EID in its forwarding table (composed of EID-Prefix routes it 198 learned from neighboring ALT Routers) and forwards it to the 199 logical next-hop on the overlay network. The primary function of 200 LISP+ALT routers is to provide a lightweight forwarding 201 infrastructure for LISP control-plane messages (Map-Request and 202 Map-Reply), and to transport data packets when the packet has the 203 same destination address in both the inner (encapsulating) 204 destination and outer destination addresses ((i.e., a Data Probe 205 packet). See [I-D.ietf-lisp-alt] for more details. 207 4. Rationale and Intent 209 With the current specifications, if an ITR is sending to all types of 210 destinations (i.e., non-LISP destinations, LISP destinations not in 211 the IPv6 EID Block, and LISP destinations in the IPv6 EID Block) the 212 only way to understand whether or not to encapsulate the traffic is 213 to perform a cache lookup and, in case of cache-miss, send a Map- 214 Request to the mapping system. In the meanwhile, packets can be 215 dropped. 217 By defining an IPv6 EID Block is possible to configure the router so 218 to natively forward all packets that have not a destination address 219 in the block, without performing any lookup whatsoever. This will 220 give a tighter control over the traffic in the initial experimental 221 phase, while facilitating its large-scale deployment. 223 The EID Block will be used only at configuration level, it is 224 RECOMMENDED not to hard-code in any way the IPv6 EID Block in the 225 router hardware. This allows avoiding locking out sites that may 226 want to switch to LISP while keeping their own IPv6 prefix, which is 227 not in the IPv6 EID Block. 229 5. Expected use 231 Sites planning to deploy LISP may request a prefix in the IPv6 EID 232 Block. Such prefix will be used for routing and endpoint 233 identification inside the site requesting it. Mappings related to 234 such prefix, or part of it, will be made available through the 235 mapping system in use or registered to one or more Map-Server(s). 236 Too guarantee reachability from the Legacy Internet the prefix could 237 be announced in the BGP routing infrastructure by one or more 238 PITR(s), possibly as part of a larger prefix, aggregating several 239 prefixes of several sites. 241 6. Block Dimension 243 The working group reached consensus on an initial allocation of a /16 244 prefix out of a /12 block which is asked to remain reserved for 245 future use as EID space. The reason of such consensus is manifold: 247 o A /16 prefix is sufficiently large to cover initial allocation and 248 requests for prefixes in the EID space in the next few years for 249 very large-scale experimentation and deployment. As a comparison 250 is worth to mention that the current LISP Beta Network ([BETA]) is 251 using a /32 prefix, hence a /16 should be sufficiently large to 252 accommodate growth in the near future. 254 o The proposed alignment provides as well a natural support for DNS. 255 In particular, reverse DNS for IPv6 in the special ip6.arpa domain 256 is represented as sequence of nibbles. A different alignment 257 would force to a binary representation. 259 7. Action Plan 261 This document requests IANA to initially allocate a /16 prefix out of 262 the IPv6 addressing space for use as EID in LISP (Locator/ID 263 Separation protocol). It is suggested to IANA to temporarily avoid 264 allocating any other address block the same /12 prefix the EID /16 265 prefix belongs to. This is to accommodate future requests of EID 266 space without fragmenting the EID addressing space. This will also 267 help from an operational point of view, since it will be sufficient 268 to change the subnet mask length in existing deployments. 270 If in the future there will be need for a larger EID Block the 271 address space adjacent the EID Block could be allocate by IANA 272 according to the current policies. 274 8. Routing Considerations 276 In order to provide connectivity between the Legacy Internet and LISP 277 sites, PITRs announcing large aggregates of the IPv6 EID Block could 278 be deployed. By doing so, PITRs will attract traffic destined to 279 LISP sites in order to encapsulate and forward it toward the specific 280 destination LISP site. Routers in the Legacy Internet MUST treat 281 announcements of prefixes from the IPv6 EID Block as normal 282 announcements, applying best current practice for traffic engineering 283 and security. 285 Even in a LISP site, not all routers need to run LISP elements. In 286 particular, routers that are not at the border of the local domain, 287 used only for intra-domain routing, do not need to provide any 288 specific LISP functionality but MUST be able to route traffic using 289 addresses in the IPv6 EID Block. 291 For the above-mentioned reasons, routers that do not run any LISP 292 element, MUST NOT include any special handling code or hardware for 293 addresses in the IPv6 EID Block. In particular, it is RECOMMENDED 294 that the default router configuration does not handle such addresses 295 in any special way. Doing differently could prevent communication 296 between the Legacy Internet and LISP sites or even break local intra- 297 domain connectivity. 299 9. Security Considerations 301 This document does not introduce new security threats in the LISP 302 architecture nor in the Legacy Internet architecture. 304 10. Acknowledgments 306 Special thanks to Roque Gagliano for his suggestions and pointers. 307 Thanks to Marla Azinger, Chris Morrow, and Peter Schoenmaker, all 308 made insightful comments on early versions of this draft. 310 11. IANA Considerations 312 This document instructs the IANA to assign a /16 IPv6 prefix for use 313 as the global LISP EID space using a hierarchical allocation as 314 outlined in [RFC5226]. During the discussion related to this 315 document, the LISP Working Group agreed in suggesting to IANA to 316 reserve adjacent addressing space for future use as EID space if 317 needs come. Following the policies outlined in [RFC5226], such space 318 will be assigned only upon IETF Consensus. This document does not 319 specify any specific value for the requested address block. 321 12. References 323 12.1. Normative References 325 [I-D.ietf-lisp] 326 Farinacci, D., Fuller, V., Meyer, D., and D. Lewis, 327 "Locator/ID Separation Protocol (LISP)", 328 draft-ietf-lisp-22 (work in progress), February 2012. 330 [I-D.ietf-lisp-alt] 331 Fuller, V., Farinacci, D., Meyer, D., and D. Lewis, "LISP 332 Alternative Topology (LISP+ALT)", draft-ietf-lisp-alt-10 333 (work in progress), December 2011. 335 [I-D.ietf-lisp-interworking] 336 Lewis, D., Meyer, D., Farinacci, D., and V. Fuller, 337 "Interworking LISP with IPv4 and IPv6", 338 draft-ietf-lisp-interworking-06 (work in progress), 339 March 2012. 341 [I-D.ietf-lisp-ms] 342 Fuller, V. and D. Farinacci, "LISP Map Server Interface", 343 draft-ietf-lisp-ms-16 (work in progress), March 2012. 345 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 346 Requirement Levels", BCP 14, RFC 2119, March 1997. 348 [RFC4632] Fuller, V. and T. Li, "Classless Inter-domain Routing 349 (CIDR): The Internet Address Assignment and Aggregation 350 Plan", BCP 122, RFC 4632, August 2006. 352 [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an 353 IANA Considerations Section in RFCs", BCP 26, RFC 5226, 354 May 2008. 356 12.2. Informative References 358 [BETA] LISP Beta Network, "http://www.lisp4.net", 2008-2011. 360 Appendix A. Document Change Log 362 Version 02 Posted April 2012. 364 o Fixed typos, nits, references. 366 o Deleted reference to IANA allocation policies. 368 Version 01 Posted October 2011. 370 o Added Section 6. 372 Version 00 Posted July 2011. 374 o Updated section "IANA Considerations" 376 o Added section "Rationale and Intent" explaining why the EID block 377 allocation is useful. 379 o Added section "Expected Use" explaining how sites can request and 380 use a prefix in the IPv6 EID Block. 382 o Added section "Action Plan" suggesting IANA to avoid allocating 383 address space adjacent the allocated EID block in order to 384 accommodate future EID space requests. 386 o Added section "Routing Consideration" describing how routers not 387 running LISP deal with the requested address block. 389 o Added the present section to keep track of changes. 391 o Rename of draft-meyer-lisp-eid-block-02.txt. 393 Authors' Addresses 395 Luigi Iannone 396 Telecom ParisTech 398 Email: ggx@gigix.net 400 Darrel Lewis 401 Cisco Systems, Inc. 403 Email: darlewis@cisco.com 405 David Meyer 406 Cisco Systems, Inc. 408 Email: dmm@cisco.com 410 Vince Fuller 411 Cisco Systems, Inc. 413 Email: vaf@cisco.com