idnits 2.17.1 draft-ietf-softwire-map-radius-10.txt: Checking boilerplate required by RFC 5378 and the IETF Trust (see https://trustee.ietf.org/license-info): ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/1id-guidelines.txt: ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/checklist : ---------------------------------------------------------------------------- ** There are 10 instances of too long lines in the document, the longest one being 26 characters in excess of 72. Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year -- The document date (March 8, 2017) is 2606 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) ** Downref: Normative reference to an Informational RFC: RFC 2869 ** Obsolete normative reference: RFC 3315 (Obsoleted by RFC 8415) ** Downref: Normative reference to an Informational RFC: RFC 3580 -- Obsolete informational reference (is this intentional?): RFC 5226 (Obsoleted by RFC 8126) -- Obsolete informational reference (is this intentional?): RFC 7749 (Obsoleted by RFC 7991) Summary: 4 errors (**), 0 flaws (~~), 1 warning (==), 3 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Softwire S. Jiang, Ed. 3 Internet-Draft Huawei Technologies Co., Ltd 4 Intended status: Standards Track Y. Fu, Ed. 5 Expires: September 9, 2017 CNNIC 6 B. Liu 7 Huawei Technologies Co., Ltd 8 P. Deacon 9 IEA Software, Inc. 10 C. Xie 11 China Telecom 12 T. Li 13 Tsinghua University 14 March 8, 2017 16 RADIUS Attribute for Softwire Address plus Port based Mechanisms 17 draft-ietf-softwire-map-radius-10 19 Abstract 21 IPv4-over-IPv6 transition mechanisms provide both IPv4 and IPv6 22 connectivity services simultaneously during the IPv4/IPv6 co-existing 23 period. The Dynamic Host Configuration Protocol for IPv6 (DHCPv6) 24 options have been defined to configure Customer Edge (CE) in MAP-E, 25 MAP-T, and Lightweight 4over6. However, in many networks, the 26 configuration information may be stored in the Authentication 27 Authorization and Accounting (AAA) servers, while user configuration 28 is mainly provided by the Broadband Network Gateway (BNG) through the 29 DHCPv6 protocol. This document defines a Remote Authentication Dial 30 In User Service (RADIUS) attribute that carries CE configuration 31 information from the AAA server to the BNG. 33 Status of This Memo 35 This Internet-Draft is submitted in full conformance with the 36 provisions of BCP 78 and BCP 79. 38 Internet-Drafts are working documents of the Internet Engineering 39 Task Force (IETF). Note that other groups may also distribute 40 working documents as Internet-Drafts. The list of current Internet- 41 Drafts is at http://datatracker.ietf.org/drafts/current/. 43 Internet-Drafts are draft documents valid for a maximum of six months 44 and may be updated, replaced, or obsoleted by other documents at any 45 time. It is inappropriate to use Internet-Drafts as reference 46 material or to cite them other than as "work in progress." 48 This Internet-Draft will expire on September 9, 2017. 50 Copyright Notice 52 Copyright (c) 2017 IETF Trust and the persons identified as the 53 document authors. All rights reserved. 55 This document is subject to BCP 78 and the IETF Trust's Legal 56 Provisions Relating to IETF Documents 57 (http://trustee.ietf.org/license-info) in effect on the date of 58 publication of this document. Please review these documents 59 carefully, as they describe your rights and restrictions with respect 60 to this document. Code Components extracted from this document must 61 include Simplified BSD License text as described in Section 4.e of 62 the Trust Legal Provisions and are provided without warranty as 63 described in the Simplified BSD License. 65 Table of Contents 67 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 68 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 69 3. Configuration process with RADIUS . . . . . . . . . . . . . . 3 70 4. Attributes . . . . . . . . . . . . . . . . . . . . . . . . . 6 71 4.1. Softwire46-Configuration Attribute . . . . . . . . . . . 6 72 4.2. S46 Container Options . . . . . . . . . . . . . . . . . . 7 73 4.3. Sub Options for S46 Container Option . . . . . . . . . . 7 74 4.3.1. S46-Rule Sub Option . . . . . . . . . . . . . . . . . 7 75 4.3.2. S46-BR Sub Option . . . . . . . . . . . . . . . . . . 8 76 4.3.3. S46-DMR Sub Option . . . . . . . . . . . . . . . . . 9 77 4.3.4. S46-V4V6Bind Sub Option . . . . . . . . . . . . . . . 9 78 4.3.5. S46-PORTPARAMS Sub Option . . . . . . . . . . . . . . 10 79 4.4. Sub Options for S46-RULE Sub Option . . . . . . . . . . . 11 80 4.4.1. Rule-IPv6-Prefix Sub Option . . . . . . . . . . . . . 11 81 4.4.2. Rule-IPv4-Prefix Sub Option . . . . . . . . . . . . . 12 82 4.4.3. EA Length Sub Option . . . . . . . . . . . . . . . . 13 83 4.5. Softwire46 Sub Options Encapsulation . . . . . . . . . . 13 84 4.6. Softwire46-Priority Attribute . . . . . . . . . . . . . . 13 85 4.7. Table of attributes . . . . . . . . . . . . . . . . . . . 14 86 5. Diameter Considerations . . . . . . . . . . . . . . . . . . . 15 87 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 15 88 7. Security Considerations . . . . . . . . . . . . . . . . . . . 15 89 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 15 90 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 16 91 9.1. Normative References . . . . . . . . . . . . . . . . . . 16 92 9.2. Informative References . . . . . . . . . . . . . . . . . 17 93 Additional Authors . . . . . . . . . . . . . . . . . . . . . . . 18 94 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 19 96 1. Introduction 98 Recently providers have started to deploy IPv6 and consider how to 99 transit to IPv6. Many transition mechanisms based on the Address 100 plus Port (A+P) [RFC6346] have been proposed for running IPv4 over 101 IPv6-only infrastructure, including MAP-E, MAP-T, and Lightweight 102 4over6. Mapping of Address and Port with Encapsulation(MAP- 103 E)[RFC7597], Mapping of Address and Port with using Translation(MAP- 104 T)[RFC7599] are stateless mechanisms for running IPv4 over IPv6-only 105 infrastructure. Lightweight 4over6[RFC7596] is a hub-and-spoke IPv4- 106 over-IPv6 tunneling mechanism, with complete independence of IPv4 and 107 IPv6 addressing. They provide both IPv4 and IPv6 connectivity 108 services simultaneously during the IPv4/IPv6 co-existing period. 109 MAP-E, MAP-T and Lightweight 4over6 have adopted Dynamic Host 110 Configuration Protocol for IPv6 (DHCPv6) [RFC3315] as auto- 111 configuring protocol. The Customer Edge (CE) uses DHCPv6 options to 112 discover the Border Relay (BR) and get Softwire46 (S46) 113 configurations. 115 In many networks, user configuration information may be stored in the 116 Authentication, Authorization, and Accounting (AAA) servers. Current 117 the AAA servers communicate using the Remote Authentication Dial In 118 User Service (RADIUS) [RFC2865] protocol. In a fixed line broadband 119 network, the Broadband Network Gateways (BNGs) act as the access 120 gateway of users. The BNGs are assumed to embed a DHCPv6 server 121 function that allows them to locally handle any DHCPv6 requests 122 initiated by hosts. 124 Since the S46 configuration information is stored in the AAA servers 125 and user configuration is mainly transmitted through DHCPv6 protocol 126 between the BNGs and hosts/CEs, new RADIUS attributes are needed to 127 propagate the information from the AAA servers to the BNGs. The 128 RADIUS attributes designed in this document are especially for the 129 MAP-E[RFC7597], MAP-T[RFC7599] and Lightweight 4over6[RFC7596], 130 providing enough information to form the correspondent DHCPv6 131 configuration options[RFC7598]. 133 2. Terminology 135 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 136 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 137 document are to be interpreted as described in [RFC2119]. 139 3. Configuration process with RADIUS 141 The below Figure 1 illustrates how the RADIUS protocol and DHCPv6 co- 142 operate to provide CE with MAP configuration information. The BNG 143 acts as a RADIUS client and as a DHCPv6 server. 145 CE BNG AAA Server 146 | | | 147 |-------1.DHCPv6 Solicit------->| | 148 | (ORO w/container option code) | | 149 | |-------2.Access-Request------->| 150 | | (S46-Configuration attriubte) | 151 | | | 152 | |<------3.Access-Accept---------| 153 |<---4.DHCPv6 Advertisement-----| (S46-Configuration attriubte) | 154 | (container option) | | 155 |-------5.DHCPv6 Request------>| | 156 | (container Option) | | 157 |<------6.DHCPv6 Reply----------| | 158 | (container option) | | 159 | | | 160 DHCPv6 RADIUS 162 Figure 1: the cooperation between DHCPv6 and RADIUS combining with 163 RADIUS authentication 165 1. First, the CE MAY initiate a DHCPv6 Solicit message that includes 166 an Option Request option(6) [RFC3315] with the S46 Container option 167 codes as defined in[RFC7598]. OPTION_S46_CONT_MAPE should be 168 included for MAP-E[RFC7597], OPTION_S46_CONT_MAPT for MAP-T[RFC7599], 169 and OPTION_S46_CONT_LW for Lightweight 4over6[RFC7596]. Note 170 however, that the ORO (Option Request option) with the S46 Container 171 option code could be optional if the network was planned as 172 S46-enabled as default. 174 2. When the BNG receives the SOLICIT, it should initiate the radius 175 Access-Request message, in which the User-Name attribute (1) should 176 be filled by the CE MAC address or interface-id or both, to the 177 RADIUS server and the User-password attribute (2) should be filled by 178 the shared password that has been preconfigured on the DHCPv6 server, 179 requesting authentication as defined in [RFC2865] with the 180 corresponding Softwire46-Configuration Attribute, which will be 181 defined in the next Section. 183 3. If the authentication request is approved by the AAA server, an 184 Access-Accept message MUST be acknowledged with the corresponding 185 Softwire46-Configuration Attribute. 187 4. After receiving the Access-Accept message with the corresponding 188 Attribute, the BNG SHOULD respond to the DHCPv6 Client (CE) with an 189 Advertisement message. 191 5. After receiving the Advertise message, the CE MAY request for the 192 corresponding S46 Container option, by including the S46 Container 193 option in the Request Message. 195 6. After receiving the client's Request messsage, containing the 196 corresponding S46 Container option the BNG SHOULD reply to the CE 197 with the message containing the S46 Container option. The 198 recommended format of the MAC address is defined as Calling-Station- 199 Id (Section 3.20 in [RFC3580] without the SSID (Service Set 200 Identifier) portion. 202 For Lightweight 4over6 [RFC7596], the subscriber's binding state 203 should be synchronized between the AAA server and the lwAFTR. If the 204 bindings are pre-configured statically, in both the AAA server and 205 the lwAFTR, the AAA server does not need to configure the lwAFTR 206 anymore. Otherwise, if the bindings are locally created on-demand in 207 the AAA server, it should inform the lwAFTR with the subscriber's 208 binding state, in order to synchronise the binding information of the 209 lwB4 with the lwAFTR. 211 The authorization operation could also be done independently after 212 the authentication process. In such a scenario, after the 213 authentication operation, the client MAY initiate a DHCPv6 Request 214 message that includes the corresponding S46 Container options. 215 Similar to the above scenario, the ORO with the corresponding S46 216 Container option code in the initial DHCPv6 request could be optional 217 if the network was planned as being S46-enabled by default. When the 218 BNG receives the DHCPv6 Request, it SHOULD initiate the radius 219 Access-Request message, which MUST contain a Service-Type attribute 220 (6) with the value Authorize Only (17), the corresponding 221 Softwire46-Configuration Attribute, and a State attribute obtained 222 from the previous authentication process according to [RFC5080]. If 223 the authorization request is approved by the AAA server, an Access- 224 Accept message MUST be acknowledged with the corresponding 225 Softwire46-Configuration Attribute. The BNG SHOULD then send the 226 DHCPv6 Reply message containing the S46 Container option. 228 In both the above-mentioned scenarios, Message-authenticator (type 229 80) [RFC2869] SHOULD be used to protect both Access-Request and 230 Access-Accept messages. 232 If the BNG does not receive the corresponding MAP-Configuration 233 Attribute in the Access-Accept it MAY fallback to a pre-configured 234 default S46 configuration, if any. If the BNG does not have any pre- 235 configured default S46 configuration, or if the BNG receives an 236 Access-Reject, then S46 cannot be established. 238 As specified in [RFC3315], section 18.1.4, "Creation and Transmission 239 of Rebind Messages ", if the DHCPv6 server to which the DHCPv6 Renew 240 message was sent at time T1 has not responded by time T2, the CE 241 (DHCPv6 client) SHOULD enter the Rebind state and attempt to contact 242 any available server. In this situation, the secondary BNG receiving 243 the DHCPv6 message MUST initiate a new Access-Request towards the AAA 244 server. The secondary BNG MAY include the MAP-Configuration 245 Attribute in its Access-Request. 247 4. Attributes 249 This section defines the Softwire46-Configuration Attribute and the 250 Softwire46-Priority Attribute. The attribute design follows 251 [RFC6158] and refers to [RFC6929]. The Softwire46-Configuration 252 Attribute carries the configuration information for MAP-E, MAP-T, and 253 Lightweight 4over6. The configuration information for each S46 254 mechanism is carried in the corresponding S46 Container option. 255 Different sub options are required for each type of S46 Container 256 option. The RADIUS attribute for Dual-Stack Lite [RFC6333] is 257 defined in [RFC6519]. 259 A client may be capable of supporting several different S46 260 mechanisms. Depending on the deployment scenario, a client might 261 request for more than one S46 mechanism at a time. The 262 Softwire46-Priority Attribute contains information allowing the 263 client to prioritize which mechanism to use, corresponding to 264 OPTION_S46_PRIORITY defined in [RFC8026]. 266 4.1. Softwire46-Configuration Attribute 268 The Softwire46-Configuration Attribute is structured as follows: 270 0 1 2 3 271 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 1 272 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 273 | Type | Length | | 274 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + 275 | | 276 + S46 Container Option(s) + 277 | | 278 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 279 Type 280 TBD 281 Length 282 2 + the length of the S46 Container option(s) specified in octects 283 S46 Container Option (s) 284 A variable field that may contains one or more S46 Container option(s), 285 defined in Section 4.2 287 4.2. S46 Container Options 289 Depending on the deployment scenario, a client might request for more 290 than one transition mechanism at a time, at least one S46 Container 291 option MUST be included in one Softwire46-Configuration Attribute. 293 0 1 2 3 294 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 1 295 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 296 | Type | Length | | 297 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + 298 | | 299 + Sub Options + 300 | | 301 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 302 Type 303 1 MAP-E Container Option 304 2 MAP-T Container Option 305 3 Lightweight 4over6 Container Option 306 Length 307 2 + the length of the sub options specified in octects 308 Sub Option 309 A variable field that contains necessary sub options defined in 310 Section 4.3 and zero or several optional sub options, defined 311 in Section 4.4. 313 4.3. Sub Options for S46 Container Option 315 4.3.1. S46-Rule Sub Option 317 Depending on deployment scenario, one Basic Mapping Rule and zero or 318 more Forwarding Mapping Rules MUST be included in one MAP-E or MAP-T 319 Container Option. 321 0 1 2 3 322 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 1 323 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 324 | SubType | SubLen | | 325 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + 326 | | 327 + Sub Options + 328 | | 329 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 330 SubType 331 1 Basic Mapping Rule (Not Forwarding Mapping Rule) 332 2 Forwarding Mapping Rule (Not Basic Mapping Rule) 333 3 Basic & Forwarding Mapping Rule 334 SubLen 335 2 + the length of the sub options specified in octects 336 Sub Option 337 A variable field that contains sub options defined in 338 Section 4.4 340 4.3.2. S46-BR Sub Option 342 There MUST be atleast one S46-BR Sub Option included in each MAP-E 343 Container Option or Lightweight 4over6 Container Option. 345 0 1 2 3 346 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 1 347 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 348 | SubType | SubLen | | 349 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + 350 | | 351 | BR-ipv6-address | 352 | | 353 + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 354 | | 355 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 357 SubType 358 4 (SubType number, for the S46-BR sub option) 359 SubLen 360 18 (the length of the S46-BR sub option) 361 BR-ipv6-address 362 a fixed-length field of 16 octects that specifies the IPv6 address 363 for the S46 BR. 365 4.3.3. S46-DMR Sub Option 367 There MUST be exactly one S46-DMR Sub Option included in one MAP-T 368 Container Option. 370 0 1 2 3 371 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 1 372 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 373 | SubType | SubLen |dmr-prefix6-len| | 374 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + 375 | dmr-ipv6-prefix | 376 | (variable length) | 377 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 379 SubType 380 5 (SubType number, for the S46-DMR sub option) 381 SubLen 382 3 + length of dmr-ipv6-prefix specified in octects 383 dmr-prefix6-len 384 8 bits long; expresses the bitmask length of the IPv6 385 prefix specified in the dmr-ipv6-prefix field. Allowed values range 386 from 0 to 96. 387 dmr-ipv6-prefix 388 a variable-length field specifying the IPv6 prefix or address 389 for the BR. This field is right-padded with zeros to the nearest 390 octect boundary when dmr-prefix6-len is not divisible by 8. 392 4.3.4. S46-V4V6Bind Sub Option 394 There MUST be atmost one S46-V4V6Bind Sub Option included in each 395 Lightweight 4over6 Container Option. 397 0 1 2 3 398 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 1 399 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 400 | SubType | SubLen | ipv4-address | 401 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 402 | (Continued) |bindprefix6-len| | 403 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + 404 | bind-ipv6-prefix | 405 | (variable length) | 406 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 408 SubType 409 6 (SubType number, for the S46-V4V6Bind sub option) 410 SubLen 411 the length of the S46-V4V6Bind sub option expressed in octects 412 ipv4-address 413 a 32-bits field that specifies an IPv4 address that appears in 414 the V4V6Bind Option 415 bindprefix6-len 416 8 bits long; expresses the bitmask length of the IPv6 prefix 417 specified in the bind-ipv6-prefix field. Allowed values range from 418 0 to 96. 419 bind-ipv6-prefix 420 a variable-length field specifying the IPv6 prefix or address for 421 the S46 CE. This field is right-padded with zeros to the nearest octect 422 boundary when bindprefix6-len is not divisible by 8. 424 4.3.5. S46-PORTPARAMS Sub Option 426 The S46-PORTPARAMS sub option specifies optional port set information 427 that MAY be provided to CEs. The S46-PORTPARAMS sub option canbe 428 included optionally by each type of S46 Container Option. 430 0 1 2 3 431 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 1 432 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 433 | SubType | SubLen | PSID-Offset | PSID-len | 434 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 435 | PSID | 436 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 438 SubType 439 7 (SubType number, for the S46-PORTPARAMS Sub Option sub option) 440 SubLen 441 6 (the length of the S46-PORTPARAMS Sub Option sub option) 442 PSID Offset 443 8 bits long field that specifies the numeric value for the S46 algorithm's excluded 444 port range/ offset bits (a bits), as per Section 5.1 of RFC 7597. 445 Allowed values are between 0 and 15. Default values for this field are specific to the 446 Softwire mechanism being implemented and are defined in the relevant specification document. 447 PSID-len 448 8 bits long; specifies the number of significant bits in the PSID 449 field. (also known as 'k'). When set to 0, the PSID field is to 450 be ignored. After the first 'a' bits, there are k bits in the 451 port number representing valid of PSID. Subsequently, the 452 address sharing ratio would be 2 ^k. 453 PSID (Port-set ID) 454 Explicit 16-bit (unsigned word) PSID value. The PSID value 455 algorithmically identifies a set of ports assigned to a CE. The 456 first k-bits on the left of this 2-octets field is the PSID 457 value. The remaining (16-k) bits on the right are padding zeros. 459 4.4. Sub Options for S46-RULE Sub Option 461 4.4.1. Rule-IPv6-Prefix Sub Option 463 The Rule-IPv6-Prefix Sub Option is necessary for every S46-RULE sub 464 option. It should appear for once and only once. 466 The IPv6 Prefix sub option is followed the framed IPv6 prefix 467 designed in [RFC3162]. 469 0 1 2 3 470 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 1 471 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 472 | SubType | SubLen | Reserved | prefix6-len | 473 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 474 | | 475 | rule-ipv6-prefix | 476 | | 477 | | 478 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 479 SubType 480 8 (SubType number, for the Rule-IPv6-Prefix6 sub option) 481 SubLen 482 20 (the length of the Rule-IPv6-Prefix6 sub option) 483 Reserved 484 Reserved for future usage. It should be set to all zero 485 prefix6-len 486 length of the IPv6 prefix, specified in the rule-ipv6-prefix 487 field, expressed in bits 488 rule-ipv6-prefix 489 a 128-bits field that specifies an IPv6 prefix that appears in 490 a MAP rule 492 4.4.2. Rule-IPv4-Prefix Sub Option 494 0 1 2 3 495 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 1 496 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 497 | SubType | SubLen | Reserved | prefix4-len | 498 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 499 | rule-ipv4-prefix | 500 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 502 SubType 503 9 (SubType number, for the Rule-IPv4-Prefix6 sub option) 504 SubLen 505 8 (the length of the Rule-IPv4-Prefix6 sub option) 506 Reserved 507 Reserved for future usage. It should be set to all zero 508 Prefix4-len 509 length of the IPv6 prefix, specified in the rule-ipv6-prefix 510 field, expressed in bits 511 rule-ipv4-prefix 512 a 32-bits field that specifies an IPv4 prefix that appears in 513 a MAP rule 515 4.4.3. EA Length Sub Option 517 0 1 2 3 518 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 1 519 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 520 | SubType | SubLen | EA-len | 521 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 523 SubType 524 10 (SubType number, for the EA Length sub option) 525 SubLen 526 4 (the length of the EA Length sub option) 527 EA-len 528 16 bits long field that specifies the Embedded-Address (EA) 529 bit length. Allowed values range from 0 to 48 531 4.5. Softwire46 Sub Options Encapsulation 533 The table below shows which encapsulated Sub Options are mandatory, 534 optional, or not permitted for each defined S46 Container Option. 536 +----------------+-------+-------+--------------------+ 537 | Sub Option | MAP-E | MAP-T | Lightweight 4over6 | 538 +----------------+-------+-------+--------------------+ 539 | S46-BR | M | N/P | M | 540 +----------------+-------+-------+--------------------+ 541 | S46-Rule | M | M | N/P | 542 +----------------+-------+-------+--------------------+ 543 | S46-DMR | N/P | M | N/P | 544 +----------------+-------+-------+--------------------+ 545 | S46-V4V6Bind | N/P | N/P | O | 546 +----------------+-------+-------+--------------------+ 547 | S46-PORTPARAMS | O | O | O | 548 +----------------+-------+-------+--------------------+ 549 | S46-Option-Code| N/P | N/P | N/P | 550 +----------------+-------+-------+--------------------+ 552 M - Maandabdatory, O - Optional, N/P - Not Permitted 554 4.6. Softwire46-Priority Attribute 556 The S46-Priority Attribute is structured as follows: 558 0 1 2 3 559 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 1 560 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 561 | Type | Length | S46-option-code | 562 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 563 | ... | S46-option-code | 564 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 566 Type 567 TBD 568 Length 569 2 + the length of the S46-option-code(s) specified in octects 570 S46-option-code 571 16-bit IANA-registered option code of the DHCPv6 option that is used to identify the 572 softwire mechanisms. S46 mechanisms are prioritized in the appearance order of the 573 S46-option-code(s) in the Softwire46-Priority Attribute. A Softwire46-Priority Attribute 574 MUST contain at least one S46-option-code. 576 4.7. Table of attributes 578 The following table provides a guide to which attributes may be found 579 in which kinds of packets, and in what quantity. 581 Request Accept Reject Challenge Accounting # Attribute 582 Request 583 0-1 0-1 0 0 0-1 TBD1 Softwire46- 584 Configuration 585 0-1 0-1 0 0 0-1 TBD2 Softwire46- 586 Priority 587 0-1 0-1 0 0 0-1 1 User-Name 588 0-1 0 0 0 0 2 User-Password 589 0-1 0-1 0 0 0-1 6 Service-Type 590 0-1 0-1 0-1 0-1 0-1 80 Message-Authenticator 592 The following table defines the meaning of the above table entries. 594 0 This attribute MUST NOT be present in packet. 595 0+ Zero or more instances of this attribute MAY be present in 596 packet. 597 0-1 Zero or one instance of this attribute MAY be present in 598 packet. 599 1 Exactly one instance of this attribute MUST be present in 600 packet. 602 5. Diameter Considerations 604 S46 Configuration using Diameter [RFC6733] is specified in [RFC7678]. 606 6. IANA Considerations 608 This document requires the assignment of two new RADIUS Attributes 609 Type in the "Radius Types" registry (currently located at 610 http://www.iana.org/assignments/radius-types for the following 611 attributes: 613 o Softwire46-Configuration Attribute TBD1 615 o Softwire46-Priority Attribute TBD2 617 IANA should allocate the numbers from the standard RADIUS Attributes 618 space using the "IETF Review" policy [RFC5226]. 620 7. Security Considerations 622 Known security vulnerabilities of the RADIUS protocol are discussed 623 in [RFC2607], [RFC2865], and[RFC2869]. Use of IPsec [RFC4301] for 624 providing security when RADIUS is carried in IPv6 is discussed in 625 [RFC3162]. 627 A malicious user may use MAC address spoofing on the shared password 628 that has been preconfigured on the DHCPv6 server to get unauthorized 629 configuration information. 631 Security considerations for MAP specific between the MAP CE and the 632 BNG are discussed in [RFC7597]. Security considerations for 633 Lightweight 4over6 are discussed in [RFC7596]. Security 634 considerations for DHCPv6-Based S46 Prioritization Mechanism are 635 discussed in [RFC8026]. Furthermore, generic DHCPv6 security 636 mechanisms can be applied DHCPv6 intercommunication between the CE 637 and the BNG. 639 Security considerations for the Diameter protocol are discussed in 640 [RFC6733]. 642 8. Acknowledgements 644 The authors would like to thank the valuable comments made by Peter 645 Lothberg, Wojciech Dec, and Suresh Krishnan for this document. This 646 document was merged with draft-sun-softwire-lw4over6-radext-01, 647 thanks to everyone who contributed to this draft. 649 This document was produced using the xml2rfc tool [RFC7749]. 651 9. References 653 9.1. Normative References 655 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 656 Requirement Levels", BCP 14, RFC 2119, 657 DOI 10.17487/RFC2119, March 1997, 658 . 660 [RFC2865] Rigney, C., Willens, S., Rubens, A., and W. Simpson, 661 "Remote Authentication Dial In User Service (RADIUS)", 662 RFC 2865, DOI 10.17487/RFC2865, June 2000, 663 . 665 [RFC2869] Rigney, C., Willats, W., and P. Calhoun, "RADIUS 666 Extensions", RFC 2869, DOI 10.17487/RFC2869, June 2000, 667 . 669 [RFC3162] Aboba, B., Zorn, G., and D. Mitton, "RADIUS and IPv6", 670 RFC 3162, DOI 10.17487/RFC3162, August 2001, 671 . 673 [RFC3315] Droms, R., Ed., Bound, J., Volz, B., Lemon, T., Perkins, 674 C., and M. Carney, "Dynamic Host Configuration Protocol 675 for IPv6 (DHCPv6)", RFC 3315, DOI 10.17487/RFC3315, July 676 2003, . 678 [RFC3580] Congdon, P., Aboba, B., Smith, A., Zorn, G., and J. Roese, 679 "IEEE 802.1X Remote Authentication Dial In User Service 680 (RADIUS) Usage Guidelines", RFC 3580, 681 DOI 10.17487/RFC3580, September 2003, 682 . 684 [RFC5080] Nelson, D. and A. DeKok, "Common Remote Authentication 685 Dial In User Service (RADIUS) Implementation Issues and 686 Suggested Fixes", RFC 5080, DOI 10.17487/RFC5080, December 687 2007, . 689 [RFC6158] DeKok, A., Ed. and G. Weber, "RADIUS Design Guidelines", 690 BCP 158, RFC 6158, DOI 10.17487/RFC6158, March 2011, 691 . 693 [RFC6929] DeKok, A. and A. Lior, "Remote Authentication Dial In User 694 Service (RADIUS) Protocol Extensions", RFC 6929, 695 DOI 10.17487/RFC6929, April 2013, 696 . 698 [RFC8026] Boucadair, M. and I. Farrer, "Unified IPv4-in-IPv6 699 Softwire Customer Premises Equipment (CPE): A DHCPv6-Based 700 Prioritization Mechanism", RFC 8026, DOI 10.17487/RFC8026, 701 November 2016, . 703 9.2. Informative References 705 [RFC2607] Aboba, B. and J. Vollbrecht, "Proxy Chaining and Policy 706 Implementation in Roaming", RFC 2607, 707 DOI 10.17487/RFC2607, June 1999, 708 . 710 [RFC4301] Kent, S. and K. Seo, "Security Architecture for the 711 Internet Protocol", RFC 4301, DOI 10.17487/RFC4301, 712 December 2005, . 714 [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an 715 IANA Considerations Section in RFCs", BCP 26, RFC 5226, 716 DOI 10.17487/RFC5226, May 2008, 717 . 719 [RFC6333] Durand, A., Droms, R., Woodyatt, J., and Y. Lee, "Dual- 720 Stack Lite Broadband Deployments Following IPv4 721 Exhaustion", RFC 6333, DOI 10.17487/RFC6333, August 2011, 722 . 724 [RFC6346] Bush, R., Ed., "The Address plus Port (A+P) Approach to 725 the IPv4 Address Shortage", RFC 6346, 726 DOI 10.17487/RFC6346, August 2011, 727 . 729 [RFC6519] Maglione, R. and A. Durand, "RADIUS Extensions for Dual- 730 Stack Lite", RFC 6519, DOI 10.17487/RFC6519, February 731 2012, . 733 [RFC6733] Fajardo, V., Ed., Arkko, J., Loughney, J., and G. Zorn, 734 Ed., "Diameter Base Protocol", RFC 6733, 735 DOI 10.17487/RFC6733, October 2012, 736 . 738 [RFC7596] Cui, Y., Sun, Q., Boucadair, M., Tsou, T., Lee, Y., and I. 739 Farrer, "Lightweight 4over6: An Extension to the Dual- 740 Stack Lite Architecture", RFC 7596, DOI 10.17487/RFC7596, 741 July 2015, . 743 [RFC7597] Troan, O., Ed., Dec, W., Li, X., Bao, C., Matsushima, S., 744 Murakami, T., and T. Taylor, Ed., "Mapping of Address and 745 Port with Encapsulation (MAP-E)", RFC 7597, 746 DOI 10.17487/RFC7597, July 2015, 747 . 749 [RFC7598] Mrugalski, T., Troan, O., Farrer, I., Perreault, S., Dec, 750 W., Bao, C., Yeh, L., and X. Deng, "DHCPv6 Options for 751 Configuration of Softwire Address and Port-Mapped 752 Clients", RFC 7598, DOI 10.17487/RFC7598, July 2015, 753 . 755 [RFC7599] Li, X., Bao, C., Dec, W., Ed., Troan, O., Matsushima, S., 756 and T. Murakami, "Mapping of Address and Port using 757 Translation (MAP-T)", RFC 7599, DOI 10.17487/RFC7599, July 758 2015, . 760 [RFC7678] Zhou, C., Taylor, T., Sun, Q., and M. Boucadair, 761 "Attribute-Value Pairs for Provisioning Customer Equipment 762 Supporting IPv4-Over-IPv6 Transitional Solutions", 763 RFC 7678, DOI 10.17487/RFC7678, October 2015, 764 . 766 [RFC7749] Reschke, J., "The "xml2rfc" Version 2 Vocabulary", 767 RFC 7749, DOI 10.17487/RFC7749, February 2016, 768 . 770 Additional Authors 771 Qiong Sun 772 China Telecom 773 Beijing China 774 Email: sunqiong@ctbri.com.cn 776 Qi Sun 777 Tsinghua University 778 Department of Computer Science, Tsinghua University 779 Beijing 100084 780 P.R.China 781 Phone: +86-10-6278-5822 782 Email: sunqibupt@gmail.com 784 Cathy Zhou 785 Huawei Technologies 786 Bantian, Longgang District 787 Shenzhen 518129 788 Email: cathy.zhou@huawei.com 790 Tina Tsou 791 Huawei Technologies(USA) 792 2330 Central Expressway 793 Santa Clara, CA 95050 794 USA 795 Email: Tina.Tsou.Zouting@huawei.com 797 ZiLong Liu 798 Tsinghua University 799 Beijing 100084 800 P.R.China 801 Phone: +86-10-6278-5822 802 Email: liuzilong8266@126.com 804 Yong Cui 805 Tsinghua University 806 Beijing 100084 807 P.R.China 808 Phone: +86-10-62603059 809 Email: yong@csnet1.cs.tsinghua.edu.cn 811 Authors' Addresses 812 Sheng Jiang 813 Huawei Technologies Co., Ltd 814 Q14, Huawei Campus, No.156 Beiqing Road 815 Hai-Dian District, Beijing, 100095 816 P.R. China 818 Email: jiangsheng@huawei.com 820 Yu Fu 821 CNNIC 822 No.4 South 4th Street, Zhongguancun 823 Hai-Dian District, Beijing, 100190 824 P.R. China 826 Email: fuyu@cnnic.cn 828 Bing Liu 829 Huawei Technologies Co., Ltd 830 Q14, Huawei Campus, No.156 Beiqing Road 831 Hai-Dian District, Beijing, 100095 832 P.R. China 834 Email: leo.liubing@huawei.com 836 Peter Deacon 837 IEA Software, Inc. 838 P.O. Box 1170 839 Veradale, WA 99037 840 USA 842 Email: peterd@iea-software.com 844 Chongfeng Xie 845 China Telecom 846 Beijing 847 P.R. China 849 Email: xiechf@ctbri.com.cn 850 Tianxiang Li 851 Tsinghua University 852 Beijing 100084 853 P.R.China 855 Email: peter416733@gmail.com