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Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year == The document doesn't use any RFC 2119 keywords, yet seems to have RFC 2119 boilerplate text. -- The document date (June 25, 2015) is 3227 days in the past. Is this intentional? Checking references for intended status: Informational ---------------------------------------------------------------------------- ** Obsolete normative reference: RFC 6145 (Obsoleted by RFC 7915) -- Obsolete informational reference (is this intentional?): RFC 2629 (Obsoleted by RFC 7749) Summary: 2 errors (**), 0 flaws (~~), 2 warnings (==), 2 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Network Working Group Q. Sun 3 Internet-Draft Z. Zhang 4 Intended status: Informational China Telecom 5 Expires: December 27, 2015 Q. Zhao 6 Beijing University of Posts and Telecommunications 7 S. Jiang 8 Huawei Technologies Co., Ltd 9 X. Lee 10 Y. Fu 11 CNNIC 12 June 25, 2015 14 Running Multiple PLATs in 464XLAT 15 draft-sun-v6ops-xlat-multi-02 17 Abstract 19 The IPv6 transition has been an ongoing process throughout the world 20 due to the exhaustion of the IPv4 address space. The 464XLAT 21 [RFC6877] provides a solution with limited IPv4 connectivity across 22 an IPv6-only network, and the android system (version 2.3 and above) 23 has already implemented the 464XLAT and the Prefix discovery solution 24 [RFC7050]. However, the current 464XLAT architecture can only deal 25 with the scenario with single PLAT in the network. When operator 26 deploys multiple PLATs with different Pref64 prefixes, 464XLAT cannot 27 cope with multiple prefixes for different destination addresses. 29 This document describes the architecture with multiple PLATs and also 30 the deployment considerations. 32 Status of This Memo 34 This Internet-Draft is submitted in full conformance with the 35 provisions of BCP 78 and BCP 79. 37 Internet-Drafts are working documents of the Internet Engineering 38 Task Force (IETF). Note that other groups may also distribute 39 working documents as Internet-Drafts. The list of current Internet- 40 Drafts is at http://datatracker.ietf.org/drafts/current/. 42 Internet-Drafts are draft documents valid for a maximum of six months 43 and may be updated, replaced, or obsoleted by other documents at any 44 time. It is inappropriate to use Internet-Drafts as reference 45 material or to cite them other than as "work in progress." 47 This Internet-Draft will expire on December 27, 2015. 49 Copyright Notice 51 Copyright (c) 2015 IETF Trust and the persons identified as the 52 document authors. All rights reserved. 54 This document is subject to BCP 78 and the IETF Trust's Legal 55 Provisions Relating to IETF Documents 56 (http://trustee.ietf.org/license-info) in effect on the date of 57 publication of this document. Please review these documents 58 carefully, as they describe your rights and restrictions with respect 59 to this document. Code Components extracted from this document must 60 include Simplified BSD License text as described in Section 4.e of 61 the Trust Legal Provisions and are provided without warranty as 62 described in the Simplified BSD License. 64 Table of Contents 66 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 67 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 68 3. Requirement of Multiple PLATs in 464XLAT . . . . . . . . . . 3 69 4. Overall Architecture of multiPLATs in 464XLAT . . . . . . . . 4 70 4.1. Prefix Management Server . . . . . . . . . . . . . . . . 4 71 4.2. Enhanced CLAT for multiPLAT . . . . . . . . . . . . . . . 5 72 5. Deployment Considerations . . . . . . . . . . . . . . . . . . 6 73 5.1. Prefix Management . . . . . . . . . . . . . . . . . . . . 6 74 5.2. DNS64 Consistency . . . . . . . . . . . . . . . . . . . . 6 75 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6 76 7. Security Considerations . . . . . . . . . . . . . . . . . . . 6 77 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 6 78 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 7 79 9.1. Normative References . . . . . . . . . . . . . . . . . . 7 80 9.2. Informative References . . . . . . . . . . . . . . . . . 7 81 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 7 83 1. Introduction 85 The exhaustion of the IPv4 address space has been a practical problem 86 that providers are facing today. Network address migration to IPv6 87 is ongoing or upcoming throughout the world. The 464XLAT 88 architecture uses the IPv4/IPv6 translation technology standardized 89 in [RFC6145] and [RFC6146]. It encourages the IPv6 transition by 90 making IPv4 service reachable across IPv6-only networks and providing 91 IPv6 and IPv4 connectivity to IPv4 or IPv6 servers and peers of 92 single-stack. The android system (version 4.3 and above) has already 93 implemented the 464XLAT [RFC6877] and the Prefix discovery method in 94 [RFC7050]. 96 However, as described in section 6.3 [RFC6877], the CLAT will use the 97 PLAT-side translation IPv6 prefix as the destination of all 98 translation packets that require stateful translation to the IPv4 99 Internet. The Prefix Discovery method [RFC7050] cannot deal with the 100 scenario when different PLATs are using with different Pref64 101 prefixes. 103 This document describes the solution of 464XLAT architecture with 104 multiple PLATs and some deployment considerations 106 2. Terminology 108 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 109 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 110 document are to be interpreted as described in [RFC2119]. 112 This document use the terminologies defined in [RFC6877] and 113 [RFC7050]. 115 3. Requirement of Multiple PLATs in 464XLAT 117 As defined in [RFC6147], it allows the implementations of DNS64 to be 118 able to map specific IPv4 address ranges to separate Pref64::/n 119 prefixes. That allows handling with special use of IPv4 addresses 120 [RFC6890]. Therefore, operator may deploy multiple NAT64s (PLATs in 121 464XLAT) for different ranges of IPv4 servers. For example, one PLAT 122 "A" is used when accessing IPv4-only servers in the data center, and 123 a different PLAT "B" is used for Internet access as described in 124 Figure 1. These two PLATs may have implemented different ALG types 125 and different QoS treatment. 127 PLAT "A" ----- IPv4-only servers in a data center 128 / 129 IPv6-only node---< 130 \ 131 PLAT "B" ----- IPv4 Internet 133 Figure 1: Use case of MultiPLAT 135 In this use case, one end user would use multiple Pref64 prefixes for 136 different destinations. 138 Another use case to deploy multiple PLATs is for load balancing. For 139 example, PLAT "A" would serve approximately half of the subscribers 140 in one network, while PLAT "B" would serve the other half as 141 described in Figure 2. 143 PLAT "A" ----- half of the subscribers 144 / 145 IPv6-only node---< 146 \ 147 PLAT "B" ----- the other half of the subscribers 149 Figure 2: Use case of MultiPLAT for load balancing 151 In this use case, one end user would still get one Pref64 for all 152 destinations, but it still needs a management system to allocate 153 different Pref64 prefixes for different users. 155 4. Overall Architecture of multiPLATs in 464XLAT 157 The overall architecture of multiPLATs in 464XLAT is depicted as 158 Figure 3. It consists of a Prefix Management Server, enhanced CLAT, 159 and multiple PLATs. The PLAT in this architecture has no difference 160 between the one in 464XLAT in [RFC6877]. 162 +-----------------+ 163 +----|Pref Mangt Server| 164 | +-----------------+ 165 | +------+ 166 +------+ | +-----+ / \ 167 | CLAT |------+------+PLAT1+----| network1 | 168 +------+ | +-----+ \ / 169 | +------+ 170 | +------+ 171 | +-----+ / \ 172 +------+PLAT2+----| network2 | 173 +-----+ \ / 174 +------+ 176 Figure 3: Architecture of multiPLATs in 464XLAT 178 4.1. Prefix Management Server 180 The Prefix Management Server includes the following modulars as 181 described in Figure 4. 183 +---------------------------------------------+ 184 | +---------------+ +-----------------+ | 185 | |Pref64 Magt | |v4addrRange Magt | | 186 | +---------------+ +-----------------+ | 187 | +---------------+ +-----------------+ | 188 | |IPv6Pref Magt | | Prefix Discovery| | 189 | +---------------+ +-----------------+ | 190 | +----------------------+ | 191 | |Policy Configuration | | 192 | +----------------------+ | 193 +---------------------------------------------+ 195 Figure 4: The implementation modulat of Prefix Management Server 197 It would be configured with the policy to allocate multiple Pref64s. 198 There may be different policies to apply. For example, it may map 199 specific IPv4 destination address ranges to separate Pref64 prefixes, 200 or map specific IPv6 source address ranges to separate Pref64 201 prefixes, or map both destination IPv4 address and source IPv6 202 address to Pref64 prefixes. The policy in Prefix Management Server 203 should be consistent with the one of the PLAT deployment. 205 The prefix discovery method should be able to cope with multiple 206 Pref64 prefixes. It may implement PCP based prefix discovery method 207 [RFC7225] to allocate multiple Pref64 prefixes. 209 4.2. Enhanced CLAT for multiPLAT 211 In addition to satisfy the requirements of existing CLAT, the 212 enhanced CLAT for multiPLAT should also implement the following 213 modulars as described in figure 5: 215 +---------------------------------------------+ 216 | +---------------+ +-----------------+ | 217 | |Pref64 Magt | |v4addrRange Magt | | 218 | +---------------+ +-----------------+ | 219 | +-----------------+ | 220 | | Prefix Discovery| | 221 | +-----------------+ | 222 +---------------------------------------------+ 224 Figure 5: The implementation modulars of enhanced CLAT 226 The prefix discovery method should be consistent with the one in the 227 Prefix Management Server. The Pref64 Management modular will extract 228 the multiple Pref64 prefixes from the prefix discovery procedure and 229 the v4addrRange Management modular will store the corresponding IPv4 230 address ranges. The prefix discovery method will get multiple Pref64 231 prefixes after the process of authentication and IPv6 address 232 allocation. Then, the CLAT will use the Pref64 prefix as the 233 destination for specific IPv4 address ranges. 235 The translation and DNS modular is the same with the traditional XLAT 236 in [RFC6877]. 238 5. Deployment Considerations 240 5.1. Prefix Management 242 The prefix management modular is important for multiPLATs in 464XLAT. 243 However, since it would compare the destination address range with 244 each packet in CLAT, it might affect the performance efficiency of 245 the client. So, operators should limit the number of address ranges, 246 and aggregate the addresses into a larger address range. 248 Besides, there might also be a maximum limit configured in CLAT on 249 the number of Pref64 prefixes and the number of address ranges. When 250 the number of address ranges exceeds the limit, the CLAT may ignore 251 the next Pref64 prefixes and use a default prefix for the rest of 252 destinations. However, this may cause issues for unexpected results. 254 5.2. DNS64 Consistency 256 464XLAT does not require DNS64 [RFC6147] when IPv4 host sends IPv4 257 packets to reach IPv4 servers. But 464XLAT networks may use DNS64 to 258 enable single stateful translation [RFC6146]. In this case, the 259 configuration policy in DNS64 should be consistent with the Prefix 260 Management Server. For example, how to map different IPv4 address 261 ranges to Pref64 prefixes and IPv6 prefixes for Preference prefixes. 263 6. IANA Considerations 265 This document has no IANA actions. 267 7. Security Considerations 269 TO BE COMPLETED 271 8. Acknowledgements 273 The authors would like to thank the following individuals who have 274 participated in the drafting, review, and discussion of this memo: TO 275 BE COMPLETED 277 This document was produced using the xml2rfc tool [RFC2629]. 279 9. References 281 9.1. Normative References 283 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 284 Requirement Levels", BCP 14, RFC 2119, March 1997. 286 [RFC6145] Li, X., Bao, C., and F. Baker, "IP/ICMP Translation 287 Algorithm", RFC 6145, April 2011. 289 [RFC6146] Bagnulo, M., Matthews, P., and I. van Beijnum, "Stateful 290 NAT64: Network Address and Protocol Translation from IPv6 291 Clients to IPv4 Servers", RFC 6146, April 2011. 293 [RFC6147] Bagnulo, M., Sullivan, A., Matthews, P., and I. van 294 Beijnum, "DNS64: DNS Extensions for Network Address 295 Translation from IPv6 Clients to IPv4 Servers", RFC 6147, 296 April 2011. 298 [RFC6877] Mawatari, M., Kawashima, M., and C. Byrne, "464XLAT: 299 Combination of Stateful and Stateless Translation", RFC 300 6877, April 2013. 302 [RFC7050] Savolainen, T., Korhonen, J., and D. Wing, "Discovery of 303 the IPv6 Prefix Used for IPv6 Address Synthesis", RFC 304 7050, November 2013. 306 9.2. Informative References 308 [RFC2629] Rose, M., "Writing I-Ds and RFCs using XML", RFC 2629, 309 June 1999. 311 [RFC6890] Cotton, M., Vegoda, L., Bonica, R., and B. Haberman, 312 "Special-Purpose IP Address Registries", BCP 153, RFC 313 6890, April 2013. 315 [RFC7225] Boucadair, M., "Discovering NAT64 IPv6 Prefixes Using the 316 Port Control Protocol (PCP)", RFC 7225, May 2014. 318 Authors' Addresses 320 Qiong Sun 321 China Telecom 322 No.118 Xizhimennei Street, Xicheng District 323 Beijing 100035 324 P.R. China 326 Email: sunqiong@ctbri.com.cn 327 Zhirong Zhang 328 China Telecom 329 No.118 Xizhimennei Street, Xicheng District 330 Beijing 100035 331 P.R. China 333 Email: zhangzhr@ctbri.com.cn 335 Qin Zhao 336 Beijing University of Posts and Telecommunications 337 Beijing 100876 338 P.R. China 340 Email: zhaoq@bupt.edu.cn 342 Sheng Jiang 343 Huawei Technologies Co., Ltd 344 Q14, Huawei Campus, No.156 Beiqing Road 345 Hai-Dian District, Beijing, 100095 346 P.R. China 348 Email: jiangsheng@huawei.com 350 Xiaodong Lee 351 CNNIC 352 No.4 South 4th Street, Zhongguancun 353 Hai-Dian District, Beijing, 100190 354 P.R. China 356 Email: xl@cnnic.cn 358 Yu Fu 359 CNNIC 360 No.4 South 4th Street, Zhongguancun 361 Hai-Dian District, Beijing, 100190 362 P.R. China 364 Email: fuyu@cnnic.cn