idnits 2.17.1 draft-ietf-ipv6-unique-local-addr-02.txt: Checking boilerplate required by RFC 5378 and the IETF Trust (see https://trustee.ietf.org/license-info): ---------------------------------------------------------------------------- ** Looks like you're using RFC 2026 boilerplate. This must be updated to follow RFC 3978/3979, as updated by RFC 4748. Checking nits according to https://www.ietf.org/id-info/1id-guidelines.txt: ---------------------------------------------------------------------------- ** The document seems to lack a 1id_guidelines paragraph about Internet-Drafts being working documents. ** The document seems to lack a 1id_guidelines paragraph about the list of current Internet-Drafts. ** The document seems to lack a 1id_guidelines paragraph about the list of Shadow Directories. == No 'Intended status' indicated for this document; assuming Proposed Standard Checking nits according to https://www.ietf.org/id-info/checklist : ---------------------------------------------------------------------------- ** There is 1 instance of too long lines in the document, the longest one being 4 characters in excess of 72. Miscellaneous warnings: ---------------------------------------------------------------------------- -- The document seems to lack a disclaimer for pre-RFC5378 work, but may have content which was first submitted before 10 November 2008. If you have contacted all the original authors and they are all willing to grant the BCP78 rights to the IETF Trust, then this is fine, and you can ignore this comment. If not, you may need to add the pre-RFC5378 disclaimer. (See the Legal Provisions document at https://trustee.ietf.org/license-info for more information.) -- Couldn't find a document date in the document -- date freshness check skipped. Checking references for intended status: Proposed Standard ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) == Missing Reference: 'RFC 2119' is mentioned on line 97, but not defined == Unused Reference: 'RFC2026' is defined on line 588, but no explicit reference was found in the text == Unused Reference: 'RFC2119' is defined on line 591, but no explicit reference was found in the text ** Downref: Normative reference to an Informational RFC: RFC 3587 (ref. 'GLOBAL') ** Obsolete normative reference: RFC 1885 (ref. 'ICMPV6') (Obsoleted by RFC 2463) ** Obsolete normative reference: RFC 2460 (ref. 'IPV6') (Obsoleted by RFC 8200) ** Downref: Normative reference to an Informational RFC: RFC 1321 (ref. 'MD5DIG') ** Obsolete normative reference: RFC 1305 (ref. 'NTP') (Obsoleted by RFC 5905) -- Possible downref: Non-RFC (?) normative reference: ref. 'POPUL' ** Obsolete normative reference: RFC 1750 (ref. 'RANDOM') (Obsoleted by RFC 4086) -- Obsolete informational reference (is this intentional?): RFC 2462 (ref. 'ADDAUTO') (Obsoleted by RFC 4862) -- Obsolete informational reference (is this intentional?): RFC 3484 (ref. 'ADDSEL') (Obsoleted by RFC 6724) -- Obsolete informational reference (is this intentional?): RFC 3315 (ref. 'DHCP6') (Obsoleted by RFC 8415) -- Obsolete informational reference (is this intentional?): RFC 1889 (ref. 'RTP') (Obsoleted by RFC 3550) Summary: 11 errors (**), 0 flaws (~~), 4 warnings (==), 7 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 INTERNET-DRAFT R. Hinden, Nokia 3 January 20, 2004 Brian Haberman, Caspian 5 Unique Local IPv6 Unicast Addresses 7 9 Status of this Memo 11 This document is an Internet-Draft and is in full conformance with 12 all provisions of Section 10 of RFC2026. Internet-Drafts are working 13 documents of the Internet Engineering Task Force (IETF), its areas, 14 and its working groups. Note that other groups may also distribute 15 working documents as Internet-Drafts. 17 Internet-Drafts are draft documents valid for a maximum of six months 18 and may be updated, replaced, or obsoleted by other documents at any 19 time. It is inappropriate to use Internet-Drafts as reference 20 material or to cite them other than as "work in progress." 22 To view the list Internet-Draft Shadow Directories, see 23 http://www.ietf.org/shadow.html. 25 This internet draft expires on July 25, 2004. 27 Abstract 29 This document defines an unicast address format that is globally 30 unique and is intended for local communications, usually inside of a 31 site. They are not expected to be routable on the global Internet 32 given current routing technology. 34 Table of Contents 36 1.0 Introduction....................................................2 37 2.0 Acknowledgments.................................................3 38 3.0 Local IPv6 Unicast Addresses....................................3 39 3.1 Format..........................................................3 40 3.1.1 Background....................................................4 41 3.2 Global ID.......................................................4 42 3.2.1 Centrally Assigned Global IDs.................................5 43 3.2.2 Locally Assigned Global IDs...................................6 44 3.2.3 Sample Code for Pseudo-Random Global ID Algorithm.............7 45 3.2.4 Analysis of the Uniqueness of Global IDs......................7 46 3.3 Scope Definition................................................8 47 4.0 Routing.........................................................8 48 5.0 Renumbering and Site Merging....................................9 49 6.0 Site Border Router and Firewall Packet Filtering................9 50 7.0 DNS Issues......................................................9 51 8.0 Application and Higher Level Protocol Issues...................10 52 9.0 Use of Local IPv6 Addresses for Local Communications...........10 53 10.0 Use of Local IPv6 Addresses with VPNs.........................11 54 11.0 Advantages and Disadvantages..................................12 55 12.0 Security Considerations.......................................12 56 13.0 IANA Considerations...........................................13 57 14.0 References....................................................13 58 14.1 Normative References..........................................13 59 14.2 Informative References........................................14 60 15.0 Authors' Addresses............................................14 61 16.0 Change Log....................................................15 63 1.0 Introduction 65 This document defines an IPv6 unicast address format that is globally 66 unique and is intended for local communications [IPV6]. These 67 addresses are called Unique Local IPv6 Unicast Addresses and are 68 abbreviated in this document as Local IPv6 addresses. They are not 69 expected to be routable on the global Internet given current routing 70 technology. They are routable inside of a more limited area such as 71 a site. They may also be routed between a limited set of sites. 73 Local IPv6 unicast addresses have the following characteristics: 75 - Globally unique prefix. 76 - Well known prefix to allow for easy filtering at site 77 boundaries. 78 - Allows sites to be combined or privately interconnected without 79 creating any address conflicts or require renumbering of 80 interfaces using these prefixes. 81 - Internet Service Provider independent and can be used for 82 communications inside of a site without having any permanent or 83 intermittent Internet connectivity. 84 - If accidentally leaked outside of a site via routing or DNS, 85 there is no conflict with any other addresses. 86 - In practice, applications may treat these addresses like global 87 scoped addresses. 89 This document defines the format of Local IPv6 addresses, how to 90 allocate them, and usage considerations including routing, site 91 border routers, DNS, application support, VPN usage, and guidelines 92 for how to use for local communication inside a site. 94 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 95 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 96 document are to be interpreted as described in [RFC 2119]. 98 2.0 Acknowledgments 100 The underlying idea of creating Local IPv6 addresses described in 101 this document been proposed a number of times by a variety of people. 102 The authors of this draft do not claim exclusive credit. Credit goes 103 to Brian Carpenter, Christian Huitema, Aidan Williams, Andrew White, 104 Charlie Perkins, and many others. The authors would also like to 105 thank Brian Carpenter, Charlie Perkins, Harald Alvestrand, Keith 106 Moore, Margaret Wasserman, Shannon Behrens, Alan Beard, Hans Kruse, 107 and Geoff Huston for their comments and suggestions on this document. 109 3.0 Local IPv6 Unicast Addresses 111 3.1 Format 113 The Local IPv6 addresses are created using a centrally allocated 114 global ID. They have the following format: 116 | 7 bits | 41 bits | 16 bits | 64 bits | 117 +--------+------------+-----------+-----------------------------+ 118 | prefix | global ID | subnet ID | interface ID | 119 +--------+------------+-----------+-----------------------------+ 121 Where: 123 prefix FC00::/7 prefix to identify Local IPv6 unicast 124 addresses. 126 global ID 41-bit global identifier used to create a 127 globally unique prefix. See section 3.2 for 128 additional information. 130 subnet ID 16-bit subnet ID is an identifier of a subnet 131 within the site. 133 interface ID 64-bit IID as defined in [ADDARCH]. 135 3.1.1 Background 137 There were a range of choices available when choosing the size of the 138 prefix and Global ID field length. There is a direct tradeoff 139 between having a Global ID field large enough to support foreseeable 140 future growth and not using too much of the IPv6 address space 141 needlessly. A reasonable way of evaluating a specific field length 142 is to compare it to a projected 2050 world population of 9.3 billion 143 [POPUL] to compare the number of resulting /48 prefixes per person. 144 A range of prefix choices is shown in the following table: 146 Prefix Global ID Number /48 Prefixes % of IPv6 147 Length Prefixes per Person Address Space 149 /11 37 137,438,953,472 15 0.049% 150 /10 38 274,877,906,944 30 0.098% 151 /9 39 549,755,813,888 59 0.195% 152 /8 40 1,099,511,627,776 118 0.391% 153 /7 41 2,199,023,255,552 236 0.781% 154 /6 42 4,398,046,511,104 473 1.563% 156 A very high utilization ratio of these allocations can be assumed 157 because no internal structure is required in the field nor is there 158 any reason to be able to aggregate the prefixes. 160 The authors believes that a /7 prefix resulting in a 41 bit Global ID 161 is a good choice. It provides for a large number of assignments 162 (i.e., 2.2 trillion) and at the same time uses less than .8% of the 163 total IPv6 address space. It is unlikely that this space will be 164 exhausted. If more than this was needed, then additional IPv6 165 address space could be allocated for this purpose. 167 3.2 Global ID 169 The allocation of global IDs should be pseudo-random [RANDOM]. They 170 should not be assigned sequentially or with well known numbers. This 171 to ensure that there is not any relationship between allocations and 172 to help clarify that these prefixes are not intended to be routed 173 globally. Specifically, these prefixes are designed to not 174 aggregate. 176 There are two ways to allocate Global IDs. These are centrally by a 177 allocation authority and locally by the site. The Global ID is split 178 into two parts for each type of allocation. The prefixes for each 179 type are: 181 FC00::/8 Centrally assigned 182 FD00::/8 Locally assigned 184 Each results in a 40-bit space to allocate. 186 Two assignment methods are included because they have different 187 properties. The centrally assigned global IDs are uniquely assigned 188 and the assignments can be escrowed to resolve any disputes regarding 189 duplicate assignments. The local assignments are free and do not 190 need any central coordination or assignment, but have a lower (but 191 still adequate) probability of being unique. It is expected that 192 large managed sites will prefer central assignments and small or 193 disconnected sites will prefer local assignments. It is recommended 194 that sites planning to use Local IPv6 addresses for extensive inter- 195 site communication, initially or as a future possibility, use a 196 centrally assigned prefix as there is no possibility of assignment 197 conflicts. Sites are free to choose either approach. 199 3.2.1 Centrally Assigned Global IDs 201 Centrally assigned global IDs MUST be generated with a pseudo-random 202 algorithm consistent with [RANDOM]. They should not be assigned 203 sequentially or by locality. This is to ensure that there is no 204 relationship between allocations and to help clarify that these 205 prefixes are not intended to be routed globally by eliminating the 206 possibility of aggregation. Specifically, these prefixes are 207 designed to not aggregate. 209 Global IDs should be assigned centrally by a single allocation 210 authority because they are pseudo-random and without any structure. 211 This is easiest to accomplish if there is a single source of the 212 assignments. 214 The requirements for centrally assigned global ID allocations are: 216 - Available to anyone in an unbiased manner. 217 - Permanent with no periodic fees. 218 - One time non-refundable allocation fee per allocation that is 219 affordable by a broad spectrum of end users when considered 220 globally. 221 - Provide mechanisms that prevent hoarding of these allocations. 222 - The ownership of each individual allocation should be private, 223 but should be escrowed. 225 The allocation authority should permit allocations to be obtained 226 without having any sort of Internet connectivity. For example in 227 addition to web based registration they should support some methods 228 like telephone, postal mail, fax, telex, etc. They should also 229 accept a variety of payment methods and currencies. 231 The reason for the use of an allocation fee for each prefix is to 232 allow this service function to operate on a cost recovery basis. An 233 acknowledged side-effect of such a mechanism is that it provides some 234 impediment to any hoarding of the these allocations. The 235 consideration of affordability is intended to keep the cost low 236 enough so as not create a barrier to anyone needing one. The charge 237 is one time to eliminate the need for an ongoing relationship with 238 the allocation authority, while acknowledging the service costs for 239 both the registration function and the enduring escrow service. The 240 charge is non-refundable in order to keep overhead low. 242 The ownership of the allocations is not needed to be public since the 243 resulting addresses are intended to be used for local communication. 244 It is escrowed to insure there are no duplicate allocations and in 245 case it is needed in the future (e.g., to resolve duplicate 246 allocation disputes, or to support a change of the central allocation 247 authority). 249 Note, there are many possible ways of of creating an allocation 250 authority. It is important to keep in mind when reviewing 251 alternatives that the goal is to pick one that can do the job. It 252 doesn't have to be perfect, only good enough to do the job at hand. 254 This document directs the IANA, in section 13.0, to delegate the 255 FC00::/8 prefix to an allocation authority to allocate centrally 256 assigned /48 prefixes consistent with the requirements defined in 257 this section. 259 3.2.2 Locally Assigned Global IDs 261 Global IDs can also be generated locally by an individual site. This 262 makes it easy to get a prefix with out the need to contact an 263 assignment authority or internet service provider. There is not as 264 high a degree of assurance that the prefix will not conflict with 265 another locally generated prefix, but the likelihood of conflict is 266 small. Sites that are not comfortable with this degree of 267 uncertainty should use a centrally assigned global ID. 269 Locally assigned global IDs MUST be generated with a pseudo-random 270 algorithm consistent with [RANDOM]. Section 3.2.3 describes a 271 suggested algorithm. It is important to insure a reasonable 272 likelihood uniqueness that all sites generating a Global IDs use a 273 functionally similar algorithm. 275 3.2.3 Sample Code for Pseudo-Random Global ID Algorithm 277 The algorithm described below is intended to be used for centrally 278 and locally assigned Global IDs. In each case the resulting global 279 ID will be used in the appropriate prefix as defined in section 3.2. 281 1) Obtain the current time of day in 64-bit NTP format [NTP]. 282 2) Obtain an EUI-64 identifier from the system running this 283 algorithm. If an EUI-64 does not exist, one can be created from 284 a 48-bit MAC address as specified in [ADDARCH]. If an EUI-64 285 cannot be obtained or created, a suitably unique identifier, 286 local to the node, should be used (e.g. system serial number). 287 3) Concatenate the time of day with the system-specific identifier 288 creating a key. 289 4) Compute an MD5 digest on the key as specified in [MD5DIG]. 290 5) Use the least significant 40 bits as the Global ID. 292 This algorithm will result in a global ID that is reasonably unique 293 and can be used as a Global ID. 295 3.2.4 Analysis of the Uniqueness of Global IDs 297 The selection of a pseudo random global ID is similar to the 298 selection of an SSRC identifier in RTP/RTCP defined in section 8.1 of 299 [RTP]. This analysis is adapted from that document. 301 Since the global ID is chosen randomly, it is possible that two or 302 more networks that have an inter-network connection using globally- 303 unique local addresses will chose the same global ID. The 304 probability of collision can be approximated based on the number of 305 inter-connections using globally-unique local addresses and the 306 length of the ID (40 bits). The formula 308 P = 1 - exp(-N**2 / 2**(L+1)) 310 approximates the probability of collision (where N is the number 311 inter-connections and L is the length of the global ID). 313 The following table shows the probability of a collision for a range 314 of inter-connections using a 40 bit global ID field. 316 Inter-connections Probability of Collision 318 2 1.81*10^-12 319 10 4.54*10^-11 320 100 4.54*10^-09 321 1000 4.54*10^-07 322 10000 4.54*10^-05 324 Based on this analysis the uniqueness of locally generated global IDs 325 is adequate for sites planning a small to moderate amount inter-site 326 communication using locally generated global IDs. Sites planning 327 more extensive inter-site communication should consider using the 328 centrally assigned global ID. 330 3.3 Scope Definition 332 By default, the scope of these addresses is global. That is, they 333 are not limited by ambiguity like the site-local addresses defined in 334 [ADDARCH]. Rather, these prefixes are globally unique, and as such, 335 their applicability is greater than site-local addresses. Their 336 limitation is in the routability of the prefixes, which is limited to 337 a site and any explicit routing agreements with other sites to 338 propagate them. Also, unlike site-locals, a site may have more than 339 one of these prefixes and use them at the same time. 341 4.0 Routing 343 Local IPv6 addresses are designed to be routed inside of a site in 344 the same manner as other types of unicast addresses. They can be 345 carried in any IPv6 routing protocol without any change. 347 It is expected that they would share the same subnet IDs with 348 provider based global unicast addresses if they were being used 349 concurrently [GLOBAL]. 351 Any routing protocol that is used between sites MUST filter out any 352 incoming or outgoing Local IPv6 unicast routes. The exception to 353 this is if specific /48 IPv6 local unicast routes have been 354 configured to allow for inter-site communication. 356 If BGP is being used at the site border with an ISP, filters MUST be 357 installed by default in the BGP configuration to keep any Local IPv6 358 address prefixes from being advertised outside of the site or for 359 these prefixes to be learned from another site. The exception to 360 this is if there are specific /48 routes created for one or more 361 Local IPv6 prefixes. 363 5.0 Renumbering and Site Merging 365 The use of Local IPv6 addresses in a site results in making 366 communication using these addresses independent of renumbering a 367 site's provider based global addresses. 369 When merging multiple sites none of the addresses created with these 370 prefixes need to be renumbered because all of the addresses are 371 unique. Routes for each specific prefix would have to be configured 372 to allow routing to work correctly between the formerly separate 373 sites. 375 6.0 Site Border Router and Firewall Packet Filtering 377 While no serious harm will be done if packets with these addresses 378 are sent outside of a site via a default route, it is recommended 379 that they be filtered to keep any packets with Local IPv6 destination 380 addresses from leaking outside of the site and to keep any site 381 prefixes from being advertised outside of their site. 383 Site border routers SHOULD install a black hole route for the Local 384 IPv6 prefix FC00::/7. This will insure that packets with Local IPv6 385 destination addresses will not be forwarded outside of the site via a 386 default route. Site border routers SHOULD respond with the 387 appropriate ICMPv6 Destination Unreachable message to inform the 388 source that the packet was not forwarded [ICMPV6]. This feedback is 389 important to avoid transport protocol timeouts. 391 Site border routers and firewalls SHOULD NOT forward any packets with 392 Local IPv6 source or destination addresses outside of the site unless 393 they have been explicitly configured with routing information about 394 other Local IPv6 prefixes. The default behavior of these devices 395 SHOULD be to filter them. Site border routers SHOULD respond with 396 the appropriate ICMPv6 Destination Unreachable message to inform the 397 source that the packet was not forwarded. 399 Additionally, domain border routers connecting autonomous systems 400 throughout the Internet SHOULD obey these recommendations for site 401 border routers. 403 7.0 DNS Issues 405 AAAA records for Local IPv6 addresses SHOULD NOT be installed in the 406 global DNS. They may be installed in a naming system local to the 407 site or kept separate from the global DNS using techniques such as 408 "two-faced" DNS. 410 If Local IPv6 address are configured in the global DNS, no harm is 411 done because they are unique and will not create any confusion. They 412 may not be reachable, but this is a property that is common to all 413 types of global IPv6 unicast addresses. 415 For future study names with Local IPv6 addresses may be resolved 416 inside of the site using dynamic naming systems such as Multicast 417 DNS. 419 8.0 Application and Higher Level Protocol Issues 421 Application and other higher level protocols can treat Local IPv6 422 addresses in the same manner as other types of global unicast 423 addresses. No special handling is required. This type of addresses 424 may not be reachable, but that is no different from other types of 425 IPv6 global unicast addresses. Applications need to be able to 426 handle multiple addresses that may or may not be reachable any point 427 in time. In most cases this complexity should be hidden in APIs. 429 From a host's perspective this difference shows up as different 430 reachability than global unicast and could be handled by default that 431 way. In some cases it is better for nodes and applications to treat 432 them differently from global unicast addresses. A starting point 433 might be to give them preference over global unicast, but fall back 434 to global unicast if a particular destination is found to be 435 unreachable. Much of this behavior can be controlled by how they are 436 allocated to nodes and put into the DNS. However it is useful if a 437 host can have both types of addresses and use them appropriately. 439 Note that the address selection mechanisms of [ADDSEL], and in 440 particular the policy override mechanism replacing default address 441 selection, are expected to be used on a site where Local IPv6 442 addresses are configured. 444 9.0 Use of Local IPv6 Addresses for Local Communications 446 Local IPv6 addresses, like global scope unicast addresses, are only 447 assigned to nodes if their use has been enabled (via IPv6 address 448 autoconfiguration [ADDAUTO], DHCPv6 [DHCP6], or manually) and 449 configured in the DNS. They are not created automatically the way 450 that IPv6 link-local addresses are and will not appear or be used 451 unless they are purposely configured. 453 In order for hosts to autoconfigure Local IPv6 addresses, routers 454 have to be configured to advertise Local IPv6 /64 prefixes in router 455 advertisements, or a DHCPv6 server must have been configured to 456 assign them. In order for a node to learn the Local IPv6 address of 457 another node, the Local IPv6 address must have been installed in the 458 DNS. For these reasons, it is straight forward to control their 459 usage in a site. 461 To limit the use of Local IPv6 addresses the following guidelines 462 apply: 464 - Nodes that are to only be reachable inside of a site: The local 465 DNS should be configured to only include the Local IPv6 466 addresses of these nodes. Nodes with only Local IPv6 addresses 467 must not be installed in the global DNS. 469 - Nodes that are to be limited to only communicate with other 470 nodes in the site: These nodes should be set to only 471 autoconfigure Local IPv6 addresses via [ADDAUTO] or to only 472 receive Local IPv6 addresses via [DHCP6]. Note: For the case 473 where both global and Local IPv6 prefixes are being advertised 474 on a subnet, this will require a switch in the devices to only 475 autoconfigure Local IPv6 addresses. 477 - Nodes that are to be reachable from inside of the site and from 478 outside of the site: The DNS should be configured to include 479 the global addresses of these nodes. The local DNS may be 480 configured to also include the Local IPv6 addresses of these 481 nodes. 483 - Nodes that can communicate with other nodes inside of the site 484 and outside of the site: These nodes should autoconfigure global 485 addresses via [ADDAUTO] or receive global address via [DHCP6]. 486 They may also obtain Local IPv6 addresses via the same 487 mechanisms. 489 10.0 Use of Local IPv6 Addresses with VPNs 491 Local IPv6 addresses can be used for inter-site Virtual Private 492 Networks (VPN) if appropriate routes are set up. Because the 493 addresses are unique these VPNs will work reliably and without the 494 need for translation. They have the additional property that they 495 will continue to work if the individual sites are renumbered or 496 merged. 498 11.0 Advantages and Disadvantages 500 11.1 Advantages 502 This approach has the following advantages: 504 - Provides Local IPv6 prefixes that can be used independently of 505 any provider based IPv6 unicast address allocations. This is 506 useful for sites not always connected to the Internet or sites 507 that wish to have a distinct prefix that can be used to localize 508 traffic inside of the site. 509 - Applications can treat these addresses in an identical manner as 510 any other type of global IPv6 unicast addresses. 511 - Sites can be merged without any renumbering of the Local IPv6 512 addresses. 513 - Sites can change their provider based IPv6 unicast address 514 without disrupting any communication using Local IPv6 addresses. 515 - Well known prefix that allows for easy filtering at site 516 boundary. 517 - Can be used for inter-site VPNs. 518 - If accidently leaked outside of a site via routing or DNS, there 519 is no conflict with any other addresses. 521 11.2 Disadvantages 523 This approach has the following disadvantages: 525 - Not possible to route Local IPv6 prefixes on the global Internet 526 with current routing technology. Consequentially, it is 527 necessary to have the default behavior of site border routers to 528 filter these addresses. 529 - There is a very low probability of non-unique locally assigned 530 global IDs being generated by the algorithm in section 3.2.3. 531 This risk can be ignored for all practical purposes, but it 532 leads to a theoretical risk of clashing address prefixes. 534 12.0 Security Considerations 536 Local IPv6 addresses do not provide any inherent security to the 537 nodes that use them. They may be used with filters at site 538 boundaries to keep Local IPv6 traffic inside of the site, but this is 539 no more or less secure than filtering any other type of global IPv6 540 unicast addresses. 542 Local IPv6 addresses do allow for address-based security mechanisms, 543 including IPSEC, across end to end VPN connections. 545 13.0 IANA Considerations 547 The IANA is instructed to allocate the FC00::/7 prefix for Unique 548 Local IPv6 unicast addresses. 550 The IANA is instructed to delegate, within a reasonable time, the 551 prefix FC00::/8 to an allocation authority for Unique Local IPv6 552 Unicast prefixes of length /48. This allocation authority shall 553 comply with the requirements described in section 3.2 of this 554 document, including in particular the charging of a modest one-time 555 fee that is to be aligned with service costs associated with the 556 allocation function and enduring escrow of the allocation data. 558 14.0 References 560 14.1 Normative References 562 [ADDARCH] Hinden, R., S. Deering, S., "IP Version 6 Addressing 563 Architecture", RFC 3515, April 2003. 565 [GLOBAL] Hinden, R., S. Deering, E. Nordmark, "IPv6 Global Unicast 566 Address Format", RFC 3587, August 2003. 568 [ICMPV6] Conta, A., S. Deering, "Internet Control Message Protocol 569 (ICMPv6) for the Internet Protocol Version 6 (IPv6) 570 Specification", RFC1885, December 1998. 572 [IPV6] Deering, S., R. Hinden, "Internet Protocol, Version 6 573 (IPv6) Specification", RFC 2460, December 1998. 575 [MD5DIG] Rivest, R., "The MD5 Message-Digest Algorithm", RFC 1321, 576 April 1992. 578 [NTP] Mills, David L., "Network Time Protocol (Version 3) 579 Specification, Implementation and Analysis", RFC 1305, 580 March 1992. 582 [POPUL] Population Reference Bureau, "World Population Data Sheet 583 of the Population Reference Bureau 2002", August 2002. 585 [RANDOM] Eastlake, D. 3rd, S. Crocker, J. Schiller, "Randomness 586 Recommendations for Security", RFC 1750, December 1994. 588 [RFC2026] Bradner, S., "The Internet Standards Process -- Revision 589 3", RFC 2026, BCP00009, October 1996. 591 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 592 Requirement Levels", RFC 2119, BCP14, March 1997. 594 14.2 Informative References 596 [ADDAUTO] Thomson, S., T. Narten, "IPv6 Stateless Address 597 Autoconfiguration", RFC 2462, December 1998. 599 [ADDSEL] Draves, R., "Default Address Selection for Internet 600 Protocol version 6 (IPv6)", RFC 3484, February 2003. 602 [DHCP6] Droms, R., et. al., "Dynamic Host Configuration Protocol 603 for IPv6 (DHCPv6)", RFC3315, July 2003. 605 [RTP] Schulzrinne, H., S. Casner, R. Frederick, V. Jacobson, 606 "RTP: A Transport Protocol for Real-Time Applications" 607 RFC1889, January 1996. 609 15.0 Authors' Addresses 611 Robert M. Hinden 612 Nokia 613 313 Fairchild Drive 614 Mountain View, CA 94043 615 USA 617 phone: +1 650 625-2004 618 email: bob.hinden@nokia.com 620 Brian Haberman 621 Caspian Networks 622 1 Park Drive, Suite 300 623 Research Triangle Park, NC 27709 624 USA 626 phone: +1-929-949-4828 627 email: brian@innovationslab.net 629 16.0 Change Log 631 Draft 633 o Removed mention of 10 euro charge and changed text in section 634 3.2.1 and IANA considerations to restate the requirement for low 635 cost allocations and added specific requirement to prevent 636 hording. 637 o Added need to send ICMPv6 destination unreachable messages if 638 packets are filtered or dropped at site boundaries. 639 o Changed format section to list prefix sizes and definition, and 640 changed discussion of prefix sizes to new background section. 641 o Various editorial changes. 643 Draft 645 o Removed example of PIR as an example of an allocation authority 646 and clarified the text that the IANA should delegate the 647 centrally assigned prefix to an allocation authority. 648 o Changed sample code for generating pseudo random Global IDs to 649 not require any human input. Changes from using birthday to 650 unique token (e.g., EUI-64, serial number, etc.) available on 651 machine running the algorithm. 652 o Added a new section analyzing the uniqueness properties of the 653 pseudo random number algorithm. 654 o Added text to recommend that centrally assigned local addresses 655 be used for site planning extensive inter-site communication. 656 o Clarified that domain border routers should follow site border 657 router recommendations. 658 o Clarified that AAAA DNS records should not be installed in the 659 global DNS. 660 o Several editorial changes. 662 Draft 664 o Changed file name to become an IPv6 w.g. group document. 665 o Clarified language in Routing and Firewall sections. 666 o Several editorial changes. 668 Draft 670 o Changed title and name of addresses defined in this document to 671 "Unique Local IPv6 Unicast Addresses" with abbreviation of 672 "Local IPv6 addresses". 673 o Several editorial changes. 675 Draft 677 o Added section on scope definition and updated application 678 requirement section. 679 o Clarified that, by default, the scope of these addresses is 680 global. 681 o Renumbered sections and general text improvements 682 o Removed reserved global ID values 683 o Added pseudo code for local allocation submitted by Brian 684 Haberman and added him as an author. 685 o Split Global ID values into centrally assigned and local 686 assignments and added text to describe local assignments 688 Draft 690 o Initial Draft