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Checking references for intended status: Informational ---------------------------------------------------------------------------- == Outdated reference: A later version (-24) exists of draft-ietf-lisp-23 ** Obsolete normative reference: RFC 5226 (Obsoleted by RFC 8126) Summary: 1 error (**), 0 flaws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: May 11, 2013 Cisco Systems, Inc. 6 D. Meyer 7 Brocade 8 V. Fuller 9 Cisco Systems, Inc. 10 November 7, 2012 12 LISP EID Block 13 draft-ietf-lisp-eid-block-03.txt 15 Abstract 17 This is a direction to IANA to allocate a /16 IPv6 prefix for use 18 with the Locator/ID Separation Protocol (LISP). The prefix will be 19 used for local intra-domain routing and global endpoint 20 identification, by sites deploying LISP as EID (Endpoint IDentifier) 21 addressing space. 23 Status of this Memo 25 This Internet-Draft is submitted in full conformance with the 26 provisions of BCP 78 and BCP 79. 28 Internet-Drafts are working documents of the Internet Engineering 29 Task Force (IETF). Note that other groups may also distribute 30 working documents as Internet-Drafts. The list of current Internet- 31 Drafts is at http://datatracker.ietf.org/drafts/current/. 33 Internet-Drafts are draft documents valid for a maximum of six months 34 and may be updated, replaced, or obsoleted by other documents at any 35 time. It is inappropriate to use Internet-Drafts as reference 36 material or to cite them other than as "work in progress." 38 This Internet-Draft will expire on May 11, 2013. 40 Copyright Notice 42 Copyright (c) 2012 IETF Trust and the persons identified as the 43 document authors. All rights reserved. 45 This document is subject to BCP 78 and the IETF Trust's Legal 46 Provisions Relating to IETF Documents 47 (http://trustee.ietf.org/license-info) in effect on the date of 48 publication of this document. Please review these documents 49 carefully, as they describe your rights and restrictions with respect 50 to this document. Code Components extracted from this document must 51 include Simplified BSD License text as described in Section 4.e of 52 the Trust Legal Provisions and are provided without warranty as 53 described in the Simplified BSD License. 55 Table of Contents 57 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 58 2. Definition of Terms . . . . . . . . . . . . . . . . . . . . . 3 59 3. Rationale and Intent . . . . . . . . . . . . . . . . . . . . . 5 60 4. Expected use . . . . . . . . . . . . . . . . . . . . . . . . . 6 61 5. Block Dimension . . . . . . . . . . . . . . . . . . . . . . . 6 62 6. Action Plan . . . . . . . . . . . . . . . . . . . . . . . . . 7 63 7. Routing Considerations . . . . . . . . . . . . . . . . . . . . 7 64 8. Security Considerations . . . . . . . . . . . . . . . . . . . 8 65 9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 8 66 10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8 67 11. References . . . . . . . . . . . . . . . . . . . . . . . . . . 8 68 11.1. Normative References . . . . . . . . . . . . . . . . . . 8 69 11.2. Informative References . . . . . . . . . . . . . . . . . 9 70 Appendix A. Document Change Log . . . . . . . . . . . . . . . . . 9 71 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 10 73 1. Introduction 75 This document directs the IANA to allocate a /16 IPv6 prefix for use 76 with the Locator/ID Separation Protocol (LISP - [I-D.ietf-lisp]), 77 LISP Map Server ([I-D.ietf-lisp-ms]), LISP Alternative Topology 78 (LISP+ALT - [I-D.ietf-lisp-alt]) (or other) mapping system, and LISP 79 Interworking ([I-D.ietf-lisp-interworking]). 81 This block will be used as global Endpoint IDentifier (EID) space 82 (Section 2). 84 2. Definition of Terms 86 LISP operates on two name spaces and introduces several new network 87 elements. This section provides high-level definitions of the LISP 88 name spaces and network elements and as such, it must not be 89 considered as an authoritative source. The reference to the 90 authoritative document for each term is included in every term 91 description. 93 Legacy Internet: The portion of the Internet that does not run LISP 94 and does not participate in LISP+ALT or any other mapping system. 96 LISP site: A LISP site is a set of routers in an edge network that 97 are under a single technical administration. LISP routers that 98 reside in the edge network are the demarcation points to separate 99 the edge network from the core network. See [I-D.ietf-lisp] for 100 more details. 102 Endpoint ID (EID): An EID is a 32-bit (for IPv4) or 128-bit (for 103 IPv6) value used in the source and destination address fields of 104 the first (most inner) LISP header of a packet. A packet that is 105 emitted by a system contains EIDs in its headers and LISP headers 106 are prepended only when the packet reaches an Ingress Tunnel 107 Router (ITR) on the data path to the destination EID. The source 108 EID is obtained via existing mechanisms used to set a host's 109 "local" IP address. An EID is allocated to a host from an EID- 110 prefix block associated with the site where the host is located. 111 See [I-D.ietf-lisp] for more details. 113 EID-prefix: A power-of-two block of EIDs that are allocated to a 114 site by an address allocation authority. See [I-D.ietf-lisp] for 115 more details. 117 EID-Prefix Aggregate: A set of EID-prefixes said to be aggregatable 118 in the [RFC4632] sense. That is, an EID-Prefix aggregate is 119 defined to be a single contiguous power-of-two EID-prefix block. 120 A prefix and a length characterize such a block. See 121 [I-D.ietf-lisp] for more details. 123 Routing LOCator (RLOC): A RLOC is an IPv4 or IPv6 address of an 124 egress tunnel router (ETR). A RLOC is the output of an EID-to- 125 RLOC mapping lookup. An EID maps to one or more RLOCs. 126 Typically, RLOCs are numbered from topologically aggregatable 127 blocks that are assigned to a site at each point to which it 128 attaches to the global Internet; where the topology is defined by 129 the connectivity of provider networks, RLOCs can be thought of as 130 Provider Aggregatable (PA) addresses. See [I-D.ietf-lisp] for 131 more details. 133 EID-to-RLOC Mapping: A binding between an EID-Prefix and the RLOC- 134 set that can be used to reach the EID-Prefix. The general term 135 "mapping" always refers to an EID-to-RLOC mapping. See 136 [I-D.ietf-lisp] for more details. 138 Ingress Tunnel Router (ITR): An Ingress Tunnel Router (ITR) is a 139 router that accepts receives IP packets from site end-systems on 140 one side and sends LISP-encapsulated IP packets toward the 141 Internet on the other side. The router treats the "inner" IP 142 destination address as an EID and performs an EID-to-RLOC mapping 143 lookup. The router then prepends an "outer" IP header with one of 144 its globally routable RLOCs in the source address field and the 145 result of the mapping lookup in the destination address field. 146 See [I-D.ietf-lisp] for more details. 148 Egress Tunnel Router (ETR): An Egress Tunnel Router (ETR) receives 149 LISP-encapsulated IP packets from the Internet on one side and 150 sends decapsulated IP packets to site end-systems on the other 151 side. An ETR router accepts an IP packet where the destination 152 address in the "outer" IP header is one of its own RLOCs. The 153 router strips the "outer" header and forwards the packet based on 154 the next IP header found. See [I-D.ietf-lisp] for more details. 156 Proxy ITR (PITR): A Proxy-ITR (PITR) acts like an ITR but does so on 157 behalf of non-LISP sites which send packets to destinations at 158 LISP sites. See [I-D.ietf-lisp-interworking] for more details. 160 Proxy ETR (PETR): A Proxy-ETR (PETR) acts like an ETR but does so on 161 behalf of LISP sites which send packets to destinations at non- 162 LISP sites. See [I-D.ietf-lisp-interworking] for more details. 164 Map Server (MS): A network infrastructure component that learns EID- 165 to-RLOC mapping entries from an authoritative source (typically an 166 ETR). A Map Server publishes these mappings in the distributed 167 mapping system. See [I-D.ietf-lisp-ms] for more details. 169 Map Resolver (MR): A network infrastructure component that accepts 170 LISP Encapsulated Map-Requests, typically from an ITR, quickly 171 determines whether or not the destination IP address is part of 172 the EID namespace; if it is not, a Negative Map-Reply is 173 immediately returned. Otherwise, the Map Resolver finds the 174 appropriate EID-to-RLOC mapping by consulting the distributed 175 mapping database system. See [I-D.ietf-lisp-ms] for more details. 177 The LISP Alternative Logical Topology (ALT): The virtual overlay 178 network made up of tunnels between LISP+ALT Routers. The Border 179 Gateway Protocol (BGP) runs between ALT Routers and is used to 180 carry reachability information for EID-prefixes. The ALT provides 181 a way to forward Map-Requests toward the ETR that "owns" an EID- 182 prefix. See [I-D.ietf-lisp-alt] for more details. 184 ALT Router: The device on which runs the ALT. The ALT is a static 185 network built using tunnels between ALT Routers. These routers 186 are deployed in a roughly-hierarchical mesh in which routers at 187 each level in the topology are responsible for aggregating EID- 188 Prefixes learned from those logically "below" them and advertising 189 summary prefixes to those logically "above" them. Prefix learning 190 and propagation between ALT Routers is done using BGP. When an 191 ALT Router receives an ALT Datagram, it looks up the destination 192 EID in its forwarding table (composed of EID-Prefix routes it 193 learned from neighboring ALT Routers) and forwards it to the 194 logical next-hop on the overlay network. The primary function of 195 LISP+ALT routers is to provide a lightweight forwarding 196 infrastructure for LISP control-plane messages (Map-Request and 197 Map-Reply), and to transport data packets when the packet has the 198 same destination address in both the inner (encapsulating) 199 destination and outer destination addresses ((i.e., a Data Probe 200 packet). See [I-D.ietf-lisp-alt] for more details. 202 3. Rationale and Intent 204 With the current specifications, if an ITR is sending to all types of 205 destinations (i.e., non-LISP destinations, LISP destinations not in 206 the IPv6 EID Block, and LISP destinations in the IPv6 EID Block) the 207 only way to understand whether or not to encapsulate the traffic is 208 to perform a cache lookup and, in case of cache-miss, send a Map- 209 Request to the mapping system. In the meanwhile, packets can be 210 dropped. 212 By defining an IPv6 EID Block is possible to configure the router so 213 to natively forward all packets that have not a destination address 214 in the block, without performing any lookup whatsoever. This will 215 give a tighter control over the traffic in the initial experimental 216 phase, while facilitating its large-scale deployment. 218 The EID Block will be used only at configuration level, it is 219 recommended not to hard-code in any way the IPv6 EID Block in the 220 router hardware. This allows avoiding locking out sites that may 221 want to switch to LISP while keeping their own IPv6 prefix, which is 222 not in the IPv6 EID Block. 224 4. Expected use 226 Sites planning to deploy LISP may request a prefix in the IPv6 EID 227 Block. Such prefix will be used for routing and endpoint 228 identification inside the site requesting it. Mappings related to 229 such prefix, or part of it, will be made available through the 230 mapping system in use or registered to one or more Map Server(s). 231 Too guarantee reachability from the Legacy Internet the prefix could 232 be announced in the BGP routing infrastructure by one or more 233 PITR(s), possibly as part of a larger prefix, aggregating several 234 prefixes of several sites. 236 5. Block Dimension 238 The working group reached consensus on an initial allocation of a /16 239 prefix out of a /12 block which is asked to remain reserved for 240 future use as EID space. The reason of such consensus is manifold: 242 o The working group agreed that /16 prefix is sufficiently large to 243 cover initial allocation and requests for prefixes in the EID 244 space in the next few years for very large-scale experimentation 245 and deployment. 247 o As a comparison, it is worth mentioning that the current LISP Beta 248 Network ([BETA]) is using a /32 prefix, with more than 250 sites 249 using a /48 sub prefix. Hence, a /16 prefix looks as sufficiently 250 large to allow the current deployment to scale up and be open for 251 interoperation with independent deployments using EIDs space in 252 the new /16 prefix. 254 o A /16 prefix is sufficiently large to only allow deployment of 255 independent (commercial) LISP enabled networks by third parties, 256 but may as well boost LISP experimentation and deployment. 258 o The /16 size and alignment allows the use to current policies to 259 allocate and distribute prefixes out of this space, without the 260 need to introduce any new specific address management policy. 262 o The proposed alignment provides as well a natural support for DNS. 263 In particular, reverse DNS for IPv6 in the special ip6.arpa domain 264 is represented as sequence of nibbles. A different alignment 265 would force to a binary representation. 267 o The use of a /16 prefix is in line with previous similar prefix 268 allocation for tunnelling protocols ([RFC3056]) and is considered 269 a useful practice ([RFC3692]). 271 6. Action Plan 273 This document requests IANA to initially allocate a /16 prefix out of 274 the IPv6 addressing space for use as EID in LISP (Locator/ID 275 Separation protocol). It is suggested to IANA to temporarily avoid 276 allocating any other address block the same /12 prefix the EID /16 277 prefix belongs to. This is to accommodate future requests of EID 278 space without fragmenting the EID addressing space. This will also 279 help from an operational point of view, since it will be sufficient 280 to change the subnet mask length in existing deployments. 282 If in the future there will be need for a larger EID Block the 283 address space adjacent the EID Block could be allocate by IANA 284 according to the current policies. 286 7. Routing Considerations 288 In order to provide connectivity between the Legacy Internet and LISP 289 sites, PITRs announcing large aggregates of the IPv6 EID Block could 290 be deployed. By doing so, PITRs will attract traffic destined to 291 LISP sites in order to encapsulate and forward it toward the specific 292 destination LISP site. Routers in the Legacy Internet must treat 293 announcements of prefixes from the IPv6 EID Block as normal 294 announcements, applying best current practice for traffic engineering 295 and security. 297 Even in a LISP site, not all routers need to run LISP elements. In 298 particular, routers that are not at the border of the local domain, 299 used only for intra-domain routing, do not need to provide any 300 specific LISP functionality but must be able to route traffic using 301 addresses in the IPv6 EID Block. 303 For the above-mentioned reasons, routers that do not run any LISP 304 element, must not include any special handling code or hardware for 305 addresses in the IPv6 EID Block. In particular, it is recommended 306 that the default router configuration does not handle such addresses 307 in any special way. Doing differently could prevent communication 308 between the Legacy Internet and LISP sites or even break local intra- 309 domain connectivity. 311 8. Security Considerations 313 This document does not introduce new security threats in the LISP 314 architecture nor in the Legacy Internet architecture. 316 9. Acknowledgments 318 Special thanks to Roque Gagliano for his suggestions and pointers. 319 Thanks to Marla Azinger, Chris Morrow, and Peter Schoenmaker, all 320 made insightful comments on early versions of this draft. 322 10. IANA Considerations 324 This document instructs the IANA to assign a /16 IPv6 prefix for use 325 as the global LISP EID space using a hierarchical allocation as 326 outlined in [RFC5226]. During the discussion related to this 327 document, the LISP Working Group agreed in suggesting to IANA to 328 reserve adjacent addressing space for future use as EID space if 329 needs come. Following the policies outlined in [RFC5226], such space 330 will be assigned only upon IETF Review. This document does not 331 specify any specific value for the requested address block. 333 11. References 335 11.1. Normative References 337 [I-D.ietf-lisp] 338 Farinacci, D., Fuller, V., Meyer, D., and D. Lewis, 339 "Locator/ID Separation Protocol (LISP)", 340 draft-ietf-lisp-23 (work in progress), May 2012. 342 [I-D.ietf-lisp-alt] 343 Fuller, V., Farinacci, D., Meyer, D., and D. Lewis, "LISP 344 Alternative Topology (LISP+ALT)", draft-ietf-lisp-alt-10 345 (work in progress), December 2011. 347 [I-D.ietf-lisp-interworking] 348 Lewis, D., Meyer, D., Farinacci, D., and V. Fuller, 349 "Interworking LISP with IPv4 and IPv6", 350 draft-ietf-lisp-interworking-06 (work in progress), 351 March 2012. 353 [I-D.ietf-lisp-ms] 354 Fuller, V. and D. Farinacci, "LISP Map Server Interface", 355 draft-ietf-lisp-ms-16 (work in progress), March 2012. 357 [RFC4632] Fuller, V. and T. Li, "Classless Inter-domain Routing 358 (CIDR): The Internet Address Assignment and Aggregation 359 Plan", BCP 122, RFC 4632, August 2006. 361 [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an 362 IANA Considerations Section in RFCs", BCP 26, RFC 5226, 363 May 2008. 365 11.2. Informative References 367 [BETA] LISP Beta Network, "http://www.lisp4.net", 2008-2011. 369 [RFC3056] Carpenter, B. and K. Moore, "Connection of IPv6 Domains 370 via IPv4 Clouds", RFC 3056, February 2001. 372 [RFC3692] Narten, T., "Assigning Experimental and Testing Numbers 373 Considered Useful", BCP 82, RFC 3692, January 2004. 375 Appendix A. Document Change Log 377 Version 03 Posted November 2012. 379 o General review of Section 5 as requested by T. Manderson and B. 380 Haberman. 382 o Dropped RFC 2119 Notation, as requested by A. Farrel and B. 383 Haberman. 385 o Changed "IETF Consensus" to "IETF Review" as pointed out by Roque 386 Gagliano. 388 o Changed every occurrence of "Map-Server" and "Map-Resolver" with 389 "Map Server" and "Map Resolver" to make the document consistent 390 with [I-D.ietf-lisp-ms]. Thanks to Job Snijders for pointing out 391 the issue. 393 Version 02 Posted April 2012. 395 o Fixed typos, nits, references. 397 o Deleted reference to IANA allocation policies. 399 Version 01 Posted October 2011. 401 o Added Section 5. 403 Version 00 Posted July 2011. 405 o Updated section "IANA Considerations" 407 o Added section "Rationale and Intent" explaining why the EID block 408 allocation is useful. 410 o Added section "Expected Use" explaining how sites can request and 411 use a prefix in the IPv6 EID Block. 413 o Added section "Action Plan" suggesting IANA to avoid allocating 414 address space adjacent the allocated EID block in order to 415 accommodate future EID space requests. 417 o Added section "Routing Consideration" describing how routers not 418 running LISP deal with the requested address block. 420 o Added the present section to keep track of changes. 422 o Rename of draft-meyer-lisp-eid-block-02.txt. 424 Authors' Addresses 426 Luigi Iannone 427 Telecom ParisTech 429 Email: luigi.iannone@telecom-paristech.fr 431 Darrel Lewis 432 Cisco Systems, Inc. 434 Email: darlewis@cisco.com 435 David Meyer 436 Brocade 438 Email: dmm@1-4-5.net 440 Vince Fuller 441 Cisco Systems, Inc. 443 Email: vaf@cisco.com