Softwire S. Jiang, Ed. Internet-Draft Huawei Technologies Co., Ltd Intended status: Standards Track Y. Fu, Ed. Expires: July 7, 2017 CNNIC B. Liu Huawei Technologies Co., Ltd P. Deacon IEA Software, Inc. C. Xie China Telecom T. Li Tsinghua University January 3, 2017 RADIUS Attribute for Softwire Address plus Port based Mechanisms draft-ietf-softwire-map-radius-09 Abstract IPv4-over-IPv6 transition mechanisms provide both IPv4 and IPv6 connectivity services simultaneously during the IPv4/IPv6 co-existing period. The Dynamic Host Configuration Protocol for IPv6 (DHCPv6) options have been defined to configure Customer Edge (CE) in MAP-E, MAP-T, and Lightweight 4over6. However, in many networks, the configuration information may be stored in the Authentication Authorization and Accounting (AAA) servers, while user configuration is mainly provided by the Broadband Network Gateway (BNG) through the DHCPv6 protocol. This document defines a Remote Authentication Dial In User Service (RADIUS) attribute that carries CE configuration information from the AAA server to the BNG. Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." This Internet-Draft will expire on July 7, 2017. Jiang, Ed., et al. Expires July 7, 2017 [Page 1] Internet-Draft draft-ietf-softwire-map-radius-09 January 2017 Copyright Notice Copyright (c) 2017 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. Configuration process with RADIUS . . . . . . . . . . . . . . 3 4. Attributes . . . . . . . . . . . . . . . . . . . . . . . . . 6 4.1. Softwire46-Configuration Attribute . . . . . . . . . . . 6 4.2. S46 Container Options . . . . . . . . . . . . . . . . . . 7 4.3. Sub Options for S46 Container Option . . . . . . . . . . 7 4.3.1. S46-Rule Sub Option . . . . . . . . . . . . . . . . . 7 4.3.2. S46-BR Sub Option . . . . . . . . . . . . . . . . . . 8 4.3.3. S46-DMR Sub Option . . . . . . . . . . . . . . . . . 9 4.3.4. S46-V4V6Bind Sub Option . . . . . . . . . . . . . . . 9 4.3.5. S46-PORTPARAMS Sub Option . . . . . . . . . . . . . . 10 4.4. Sub Options for S46-RULE Sub Option . . . . . . . . . . . 11 4.4.1. Rule-IPv6-Prefix Sub Option . . . . . . . . . . . . . 11 4.4.2. Rule-IPv4-Prefix Sub Option . . . . . . . . . . . . . 12 4.4.3. EA Length Sub Option . . . . . . . . . . . . . . . . 13 4.5. Softwire46 Sub Options Encapsulation . . . . . . . . . . 13 4.6. Softwire46-Priority Attribute . . . . . . . . . . . . . . 13 4.7. Table of attributes . . . . . . . . . . . . . . . . . . . 14 5. Diameter Considerations . . . . . . . . . . . . . . . . . . . 15 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 15 7. Security Considerations . . . . . . . . . . . . . . . . . . . 15 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 15 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 16 9.1. Normative References . . . . . . . . . . . . . . . . . . 16 9.2. Informative References . . . . . . . . . . . . . . . . . 17 Additional Authors . . . . . . . . . . . . . . . . . . . . . . . 18 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 19 Jiang, Ed., et al. Expires July 7, 2017 [Page 2] Internet-Draft draft-ietf-softwire-map-radius-09 January 2017 1. Introduction Recently providers have started to deploy IPv6 and consider how to transit to IPv6. Many transition mechanisms based on the Address plus Port (A+P) [RFC6346] have been proposed for running IPv4 over IPv6-only infrastructure, including MAP-E, MAP-T, and Lightweight 4over6. Mapping of Address and Port with Encapsulation(MAP- E)[RFC7597], Mapping of Address and Port with using Translation(MAP- T)[RFC7599] are stateless mechanisms for running IPv4 over IPv6-only infrastructure. Lightweight 4over6[RFC7596] is a hub-and-spoke IPv4- over-IPv6 tunneling mechanism, with complete independence of IPv4 and IPv6 addressing. They provide both IPv4 and IPv6 connectivity services simultaneously during the IPv4/IPv6 co-existing period. MAP-E, MAP-T and Lightweight 4over6 have adopted Dynamic Host Configuration Protocol for IPv6 (DHCPv6) [RFC3315] as auto- configuring protocol. The Customer Edge (CE) uses DHCPv6 options to discover the Border Relay (BR) and get Softwire46 (S46) configurations. In many networks, user configuration information may be stored in the Authentication, Authorization, and Accounting (AAA) servers. Current the AAA servers communicate using the Remote Authentication Dial In User Service (RADIUS) [RFC2865] protocol. In a fixed line broadband network, the Broadband Network Gateways (BNGs) act as the access gateway of users. The BNGs are assumed to embed a DHCPv6 server function that allows them to locally handle any DHCPv6 requests initiated by hosts. Since the S46 configuration information is stored in the AAA servers and user configuration is mainly transmitted through DHCPv6 protocol between the BNGs and hosts/CEs, new RADIUS attributes are needed to propagate the information from the AAA servers to the BNGs. The RADIUS attributes designed in this document are especially for the MAP-E[RFC7597], MAP-T[RFC7599] and Lightweight 4over6[RFC7596], providing enough information to form the correspondent DHCPv6 configuration options[RFC7598]. 2. Terminology The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119]. 3. Configuration process with RADIUS The below Figure 1 illustrates how the RADIUS protocol and DHCPv6 co- operate to provide CE with MAP configuration information. The BNG acts as a RADIUS client and as a DHCPv6 server. Jiang, Ed., et al. Expires July 7, 2017 [Page 3] Internet-Draft draft-ietf-softwire-map-radius-09 January 2017 CE BNG AAA Server | | | |-----1.DHCPv6 Solicit----->| | | (ORO w/container option) | | | |-------2.Access-Request------->| | | (S46-Configuration attriubte) | | | | | |<------3.Access-Accept---------| |<--4.DHCPv6 Advertisement--| (S46-Configuration attriubte) | | | | |-----5.DHCPv6 Request---->| | | (container Option) | | |<----6.DHCPv6 Reply--------| | | (cointainer option) | | | | | DHCPv6 RADIUS Figure 1: the cooperation between DHCPv6 and RADIUS combining with RADIUS authentication 1. First, the CE MAY initiate a DHCPv6 Solicit message that includes an Option Request option(6) [RFC3315] with the S46 Container options as defined in[RFC7598]. OPTION_S46_CONT_MAPE should be included for MAP-E[RFC7597], OPTION_S46_CONT_MAPT for MAP-T[RFC7599], and OPTION_S46_CONT_LW for Lightweight 4over6[RFC7596]. Note however, that the ORO (Option Request option) with the S46 Container option code could be optional if the network was planned as S46-enabled as default. 2. When the BNG receives the SOLICIT, it should initiate the radius Access-Request message, in which the User-Name attribute (1) should be filled by the CE MAC address or interface-id or both, to the RADIUS server and the User-password attribute (2) should be filled by the shared password that has been preconfigured on the DHCPv6 server, requesting authentication as defined in [RFC2865] with the corresponding Softwire46-Configuration Attribute, which will be defined in the next Section. 3. If the authentication request is approved by the AAA server, an Access-Accept message MUST be acknowledged with the corresponding Softwire46-Configuration Attribute. 4. After receiving the Access-Accept message with the corresponding Attribute, the BNG SHOULD respond to the CE with an Advertisement message. Jiang, Ed., et al. Expires July 7, 2017 [Page 4] Internet-Draft draft-ietf-softwire-map-radius-09 January 2017 5. After receiving the Advertise message, the CE MAY request for the corresponding S46 Container option, by including the S46 Container option in the Request Message. 6. After receiving the client's Request messsage, containing the corresponding S46 Container option the BNG SHOULD reply to the CE with the message containing the S46 Container option. The recommended format of the MAC address is defined as Calling-Station- Id (Section 3.20 in [RFC3580] without the SSID (Service Set Identifier) portion. For Lightweight 4over6 [RFC7596], the subscriber's binding state should be synchronized between the AAA server and the lwAFTR. If the bindings are pre-configured statically, in both the AAA server and the lwAFTR, the AAA server does not need to configure the lwAFTR anymore. Otherwise, if the bindings are locally created on-demand in the AAA server, it should inform the lwAFTR with the subscriber's binding state, in order to synchronise the binding information of the lwB4 with the lwAFTR. The authorization operation could also be done independently after the authentication process. In such a scenario, after the authentication operation, the client MAY initiate a DHCPv6 Request message that includes the corresponding S46 Container options. Similar to the above scenario, the ORO with the corresponding S46 Container option code in the initial DHCPv6 request could be optional if the network was planned as being S46-enabled vy default. When the BNG receives the DHCPv6 Request, it SHOULD initiate the radius Access-Request message, which MUST contain a Service-Type attribute (6) with the value Authorize Only (17), the corresponding Softwire46-Configuration Attribute, and a State attribute obtained from the previous authentication process according to [RFC5080]. If the authorization request is approved by the AAA server, an Access- Accept message MUST be acknowledged with the corresponding Softwire46-Configuration Attribute. The BNG SHOULD then send the DHCPv6 Reply message containing the S46 Container option. In both the above-mentioned scenarios, Message-authenticator (type 80) [RFC2869] SHOULD be used to protect both Access-Request and Access-Accept messages. If the BNG does not receive the corresponding MAP-Configuration Attribute in the Access-Accept it MAY fallback to a pre-configured default S46 configuration, if any. If the BNG does not have any pre- configured default S46 configuration, or if the BNG receives an Access-Reject, then S46 cannot be established. Jiang, Ed., et al. Expires July 7, 2017 [Page 5] Internet-Draft draft-ietf-softwire-map-radius-09 January 2017 As specified in [RFC3315], section 18.1.4, "Creation and Transmission of Rebind Messages ", if the DHCPv6 server to which the DHCPv6 Renew message was sent at time T1 has not responded by time T2, the CE (DHCPv6 client) SHOULD enter the Rebind state and attempt to contact any available server. In this situation, the secondary BNG receiving the DHCPv6 message MUST initiate a new Access-Request towards the AAA server. The secondary BNG MAY include the MAP-Configuration Attribute in its Access-Request. 4. Attributes This section defines the Softwire46-Configuration Attribute and the Softwire46-Priority Attribute. The attribute design follows [RFC6158] and refers to [RFC6929]. The Softwire46-Configuration Attribute carries the configuration information for MAP-E, MAP-T, and Lightweight 4over6. The configuration information for each S46 mechanism is carried in the corresponding S46 Container option. Different sub options are required for each type of S46 Container option. The RADIUS attribute for Dual-Stack Lite [RFC6333] is defined in [RFC6519]. A client may be capable of supporting several different S46 mechanisms. Depending on the deployment scenario, a client might request for more than one S46 mechanism at a time. The Softwire46-Priority Attribute contains information allowing the client to prioritize which mechanism to use, corresponding to OPTION_S46_PRIORITY defined in [RFC8026]. 4.1. Softwire46-Configuration Attribute The Softwire46-Configuration Attribute is structured as follows: 0 1 2 3 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | | + S46 Container Option(s) + | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Type TBD Length 2 + the length of the S46 Container option(s) specified in octects S46 Container Option (s) A variable field that may contains one or more S46 Container option(s), defined in Section 4.2 Jiang, Ed., et al. Expires July 7, 2017 [Page 6] Internet-Draft draft-ietf-softwire-map-radius-09 January 2017 4.2. S46 Container Options Depending on the deployment scenario, a client might request for more than one transition mechanism at a time, at least one S46 Container option MUST be included in one Softwire46-Configuration Attribute. 0 1 2 3 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | | + Sub Options + | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Type 1 MAP-E Container Option 2 MAP-T Container Option 3 Lightweight 4over6 Container Option Length 2 + the length of the sub options specified in octects Sub Option A variable field that contains necessary sub options defined in Section 4.3 and zero or several optional sub options, defined in Section 4.4. 4.3. Sub Options for S46 Container Option 4.3.1. S46-Rule Sub Option Depending on deployment scenario, one Basic Mapping Rule and zero or more Forwarding Mapping Rules MUST be included in one MAP-E or MAP-T Container Option. Jiang, Ed., et al. Expires July 7, 2017 [Page 7] Internet-Draft draft-ietf-softwire-map-radius-09 January 2017 0 1 2 3 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | SubType | SubLen | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | | + Sub Options + | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ SubType 1 Basic Mapping Rule (Not Forwarding Mapping Rule) 2 Forwarding Mapping Rule (Not Basic Mapping Rule) 3 Basic & Forwarding Mapping Rule SubLen 2 + the length of the sub options specified in octects Sub Option A variable field that contains sub options defined in Section 4.4 4.3.2. S46-BR Sub Option There MUST be atleast one S46-BR Sub Option included in each MAP-E Container Option or Lightweight 4over6 Container Option. 0 1 2 3 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | SubType | SubLen | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | | | BR-ipv6-address | | | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ SubType 4 (SubType number, for the S46-BR sub option) SubLen 18 (the length of the S46-BR sub option) BR-ipv6-address a fixed-length field of 16 octects that specifies the IPv6 address for the S46 BR. Jiang, Ed., et al. Expires July 7, 2017 [Page 8] Internet-Draft draft-ietf-softwire-map-radius-09 January 2017 4.3.3. S46-DMR Sub Option There MUST be exactly one S46-DMR Sub Option included in one MAP-T Container Option. 0 1 2 3 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | SubType | SubLen |dmr-prefix6-len| | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | dmr-ipv6-prefix | | (variable length) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ SubType 5 (SubType number, for the S46-DMR sub option) SubLen 3 + length of dmr-ipv6-prefix specified in octects dmr-prefix6-len 8 bits longs; expresses the bitmask length of the IPv6 prefix specified in the dmr-ipv6-prefix field. Allowed values range from 0-96. dmr-ipv6-prefix a variable-length field specifying the IPv6 prefix or address for the BR. This field is right-padded with zeros to the nearest octect boundary when dmr-prefix6-len is not divisible by 8. 4.3.4. S46-V4V6Bind Sub Option There MUST be atmost one S46-V4V6Bind Sub Option included in each Lightweight 4over6 Container Option. Jiang, Ed., et al. Expires July 7, 2017 [Page 9] Internet-Draft draft-ietf-softwire-map-radius-09 January 2017 0 1 2 3 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | SubType | SubLen | ipv4-address | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | (Continued) |bindprefix6-len| | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | bind-ipv6-prefix | | (variable length) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ SubType 6 (SubType number, for the S46-V4V6Bind sub option) SubLen the length of the S46-V4V6Bind sub option expressed in octects ipv4-address a 32-bits field that specifies an IPv4 address that appears in the V4V6Bind Option bindprefix6-len 8 bits long; expresses the bitmask length of the IPv6 prefix specified in the bind-ipv6-prefix field. Allowed values range from 0 to 96. bind-ipv6-prefix a variable-length field specifying the IPv6 prefix or address for the S46 CE. This field is right-padded with zeros to the nearest octect boundary when bindprefix6-len is not divisible by 8. 4.3.5. S46-PORTPARAMS Sub Option The S46-PORTPARAMS sub option specifies optional port set information that MAY be provided to CEs. The S46-PORTPARAMS sub option canbe included optionally by each type of S46 Container Option. Jiang, Ed., et al. Expires July 7, 2017 [Page 10] Internet-Draft draft-ietf-softwire-map-radius-09 January 2017 0 1 2 3 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | SubType | SubLen | PSID-Offset | PSID-len | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | PSID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ SubType 7 (SubType number, for the S46-PORTPARAMS Sub Option sub option) SubLen 6 (the length of the S46-PORTPARAMS Sub Option sub option) PSID Offset 8 bits long field that specifies the numeric value for the S46 algorithm's excluded port range/ offset bits (a bits), as per Section 5.1 of RFC 7597. Allowed values are between 0 and 15. Default values for this field are specific to the Softwire mechanism being implemented and are defined in the relevant specification document. PSID-len 8 bits long; specifies the number of significant bits in the PSID field. (also known as 'k'). When set to 0, the PSID field is to be ignored. After the first 'a' bits, there are k bits in the port number representing valid of PSID. Subsequently, the address sharing ratio would be 2 ^k. PSID (Port-set ID) Explicit 16-bit (unsigned word) PSID value. The PSID value algorithmically identifies a set of ports assigned to a CE. The first k-bits on the left of this 2-octets field is the PSID value. The remaining (16-k) bits on the right are padding zeros. 4.4. Sub Options for S46-RULE Sub Option 4.4.1. Rule-IPv6-Prefix Sub Option The Rule-IPv6-Prefix Sub Option is necessary for every S46-RULE sub option. It should appear for once and only once. The IPv6 Prefix sub option is followed the framed IPv6 prefix designed in [RFC3162]. Jiang, Ed., et al. Expires July 7, 2017 [Page 11] Internet-Draft draft-ietf-softwire-map-radius-09 January 2017 0 1 2 3 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | SubType | SubLen | Reserved | prefix6-len | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | | rule-ipv6-prefix | | | | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ SubType 9 (SubType number, for the Rule-IPv6-Prefix6 sub option) SubLen 20 (the length of the Rule-IPv6-Prefix6 sub option) Reserved Reserved for future usage. It should be set to all zero prefix6-len length of the IPv6 prefix, specified in the rule-ipv6-prefix field, expressed in bits rule-ipv6-prefix a 128-bits field that specifies an IPv6 prefix that appears in a MAP rule 4.4.2. Rule-IPv4-Prefix Sub Option 0 1 2 3 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | SubType | SubLen | Reserved | prefix4-len | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | rule-ipv4-prefix | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ SubType 10 (SubType number, for the Rule-IPv4-Prefix6 sub option) SubLen 8 (the length of the Rule-IPv4-Prefix6 sub option) Reserved Reserved for future usage. It should be set to all zero Prefix4-len length of the IPv6 prefix, specified in the rule-ipv6-prefix field, expressed in bits rule-ipv4-prefix a 32-bits field that specifies an IPv4 prefix that appears in a MAP rule Jiang, Ed., et al. Expires July 7, 2017 [Page 12] Internet-Draft draft-ietf-softwire-map-radius-09 January 2017 4.4.3. EA Length Sub Option 0 1 2 3 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | SubType | SubLen | EA-len | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ SubType 11 (SubType number, for the EA Length sub option) SubLen 4 (the length of the EA Length sub option) EA-len 16 bits long field that specifies the Embedded-Address (EA) bit length. Allowed values range from 0 to 48 4.5. Softwire46 Sub Options Encapsulation The table below shows which encapsulated Sub Options are mandatory, optional, or not permitted for each defined S46 Container Option. +----------------+-------+-------+--------------------+ | Sub Option | MAP-E | MAP-T | Lightweight 4over6 | +----------------+-------+-------+--------------------+ | S46-BR | M | N/P | M | +----------------+-------+-------+--------------------+ | S46-Rule | M | M | N/P | +----------------+-------+-------+--------------------+ | S46-DMR | N/P | M | N/P | +----------------+-------+-------+--------------------+ | S46-V4V6Bind | N/P | N/P | O | +----------------+-------+-------+--------------------+ | S46-PORTPARAMS | O | O | O | +----------------+-------+-------+--------------------+ | S46-Option-Code| N/P | N/P | N/P | +----------------+-------+-------+--------------------+ M - Maandabdatory, O - Optional, N/P - Not Permitted 4.6. Softwire46-Priority Attribute The S46-Priority Attribute is structured as follows: Jiang, Ed., et al. Expires July 7, 2017 [Page 13] Internet-Draft draft-ietf-softwire-map-radius-09 January 2017 0 1 2 3 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length | S46-option-code | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | S46-option-code | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Type TBD Length 2 + the length of the S46-option-code(s) specified in octects S46-option-code 16-bit IANA-registered option code of the DHCPv6 option that is used to identify the softwire mechanisms. S46 mechanisms are prioritized in the appearance order of the S46-option-code(s) in the Softwire46-Priority Attribute. A Softwire46-Priority Attribute MUST contain at least one S46-option-code. 4.7. Table of attributes The following table provides a guide to which attributes may be found in which kinds of packets, and in what quantity. Request Accept Reject Challenge Accounting # Attribute Request 0-1 0-1 0 0 0-1 TBD1 Softwire46- Configuration 0-1 0-1 0 0 0-1 TBD2 Softwire46- Priority 0-1 0-1 0 0 0-1 1 User-Name 0-1 0 0 0 0 2 User-Password 0-1 0-1 0 0 0-1 6 Service-Type 0-1 0-1 0-1 0-1 0-1 80 Message-Authenticator The following table defines the meaning of the above table entries. 0 This attribute MUST NOT be present in packet. 0+ Zero or more instances of this attribute MAY be present in packet. 0-1 Zero or one instance of this attribute MAY be present in packet. 1 Exactly one instance of this attribute MUST be present in packet. Jiang, Ed., et al. Expires July 7, 2017 [Page 14] Internet-Draft draft-ietf-softwire-map-radius-09 January 2017 5. Diameter Considerations S46 Configuration using Diameter [RFC6733] is specified in [RFC7678]. 6. IANA Considerations This document requires the assignment of two new RADIUS Attributes Type in the "Radius Types" registry (currently located at http://www.iana.org/assignments/radius-types for the following attributes: o Softwire46-Configuration Attribute TBD1 o Softwire46-Priority Attribute TBD2 IANA should allocate the numbers from the standard RADIUS Attributes space using the "IETF Review" policy [RFC5226]. 7. Security Considerations Known security vulnerabilities of the RADIUS protocol are discussed in [RFC2607], [RFC2865], and[RFC2869]. Use of IPsec [RFC4301] for providing security when RADIUS is carried in IPv6 is discussed in [RFC3162]. A malicious user may use MAC address spoofing on the shared password that has been preconfigured on the DHCPv6 server to get unauthorized configuration information. Security considerations for MAP specific between the MAP CE and the BNG are discussed in [RFC7597]. Security considerations for Lightweight 4over6 are discussed in [RFC7596]. Security considerations for DHCPv6-Based S46 Prioritization Mechanism are discussed in [RFC8026]. Furthermore, generic DHCPv6 security mechanisms can be applied DHCPv6 intercommunication between the CE and the BNG. Security considerations for the Diameter protocol are discussed in [RFC6733]. 8. Acknowledgements The authors would like to thank the valuable comments made by Peter Lothberg, Wojciech Dec, and Suresh Krishnan for this document. This document was merged with draft-sun-softwire-lw4over6-radext-01, thanks to everyone who contributed to this draft. This document was produced using the xml2rfc tool [RFC7749]. Jiang, Ed., et al. Expires July 7, 2017 [Page 15] Internet-Draft draft-ietf-softwire-map-radius-09 January 2017 9. References 9.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC2865] Rigney, C., Willens, S., Rubens, A., and W. Simpson, "Remote Authentication Dial In User Service (RADIUS)", RFC 2865, DOI 10.17487/RFC2865, June 2000, . [RFC2869] Rigney, C., Willats, W., and P. Calhoun, "RADIUS Extensions", RFC 2869, DOI 10.17487/RFC2869, June 2000, . [RFC3162] Aboba, B., Zorn, G., and D. Mitton, "RADIUS and IPv6", RFC 3162, DOI 10.17487/RFC3162, August 2001, . [RFC3315] Droms, R., Ed., Bound, J., Volz, B., Lemon, T., Perkins, C., and M. Carney, "Dynamic Host Configuration Protocol for IPv6 (DHCPv6)", RFC 3315, DOI 10.17487/RFC3315, July 2003, . [RFC3580] Congdon, P., Aboba, B., Smith, A., Zorn, G., and J. Roese, "IEEE 802.1X Remote Authentication Dial In User Service (RADIUS) Usage Guidelines", RFC 3580, DOI 10.17487/RFC3580, September 2003, . [RFC5080] Nelson, D. and A. DeKok, "Common Remote Authentication Dial In User Service (RADIUS) Implementation Issues and Suggested Fixes", RFC 5080, DOI 10.17487/RFC5080, December 2007, . [RFC6158] DeKok, A., Ed. and G. Weber, "RADIUS Design Guidelines", BCP 158, RFC 6158, DOI 10.17487/RFC6158, March 2011, . [RFC6929] DeKok, A. and A. Lior, "Remote Authentication Dial In User Service (RADIUS) Protocol Extensions", RFC 6929, DOI 10.17487/RFC6929, April 2013, . Jiang, Ed., et al. Expires July 7, 2017 [Page 16] Internet-Draft draft-ietf-softwire-map-radius-09 January 2017 [RFC8026] Boucadair, M. and I. Farrer, "Unified IPv4-in-IPv6 Softwire Customer Premises Equipment (CPE): A DHCPv6-Based Prioritization Mechanism", RFC 8026, DOI 10.17487/RFC8026, November 2016, . 9.2. Informative References [RFC2607] Aboba, B. and J. Vollbrecht, "Proxy Chaining and Policy Implementation in Roaming", RFC 2607, DOI 10.17487/RFC2607, June 1999, . [RFC4301] Kent, S. and K. Seo, "Security Architecture for the Internet Protocol", RFC 4301, DOI 10.17487/RFC4301, December 2005, . [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an IANA Considerations Section in RFCs", BCP 26, RFC 5226, DOI 10.17487/RFC5226, May 2008, . [RFC6333] Durand, A., Droms, R., Woodyatt, J., and Y. Lee, "Dual- Stack Lite Broadband Deployments Following IPv4 Exhaustion", RFC 6333, DOI 10.17487/RFC6333, August 2011, . [RFC6346] Bush, R., Ed., "The Address plus Port (A+P) Approach to the IPv4 Address Shortage", RFC 6346, DOI 10.17487/RFC6346, August 2011, . [RFC6519] Maglione, R. and A. Durand, "RADIUS Extensions for Dual- Stack Lite", RFC 6519, DOI 10.17487/RFC6519, February 2012, . [RFC6733] Fajardo, V., Ed., Arkko, J., Loughney, J., and G. Zorn, Ed., "Diameter Base Protocol", RFC 6733, DOI 10.17487/RFC6733, October 2012, . [RFC7596] Cui, Y., Sun, Q., Boucadair, M., Tsou, T., Lee, Y., and I. Farrer, "Lightweight 4over6: An Extension to the Dual- Stack Lite Architecture", RFC 7596, DOI 10.17487/RFC7596, July 2015, . Jiang, Ed., et al. Expires July 7, 2017 [Page 17] Internet-Draft draft-ietf-softwire-map-radius-09 January 2017 [RFC7597] Troan, O., Ed., Dec, W., Li, X., Bao, C., Matsushima, S., Murakami, T., and T. Taylor, Ed., "Mapping of Address and Port with Encapsulation (MAP-E)", RFC 7597, DOI 10.17487/RFC7597, July 2015, . [RFC7598] Mrugalski, T., Troan, O., Farrer, I., Perreault, S., Dec, W., Bao, C., Yeh, L., and X. Deng, "DHCPv6 Options for Configuration of Softwire Address and Port-Mapped Clients", RFC 7598, DOI 10.17487/RFC7598, July 2015, . [RFC7599] Li, X., Bao, C., Dec, W., Ed., Troan, O., Matsushima, S., and T. Murakami, "Mapping of Address and Port using Translation (MAP-T)", RFC 7599, DOI 10.17487/RFC7599, July 2015, . [RFC7678] Zhou, C., Taylor, T., Sun, Q., and M. Boucadair, "Attribute-Value Pairs for Provisioning Customer Equipment Supporting IPv4-Over-IPv6 Transitional Solutions", RFC 7678, DOI 10.17487/RFC7678, October 2015, . [RFC7749] Reschke, J., "The "xml2rfc" Version 2 Vocabulary", RFC 7749, DOI 10.17487/RFC7749, February 2016, . Additional Authors Jiang, Ed., et al. Expires July 7, 2017 [Page 18] Internet-Draft draft-ietf-softwire-map-radius-09 January 2017 Qiong Sun China Telecom Beijing China Email: sunqiong@ctbri.com.cn Qi Sun Tsinghua University Department of Computer Science, Tsinghua University Beijing 100084 P.R.China Phone: +86-10-6278-5822 Email: sunqibupt@gmail.com Cathy Zhou Huawei Technologies Bantian, Longgang District Shenzhen 518129 Email: cathy.zhou@huawei.com Tina Tsou Huawei Technologies(USA) 2330 Central Expressway Santa Clara, CA 95050 USA Email: Tina.Tsou.Zouting@huawei.com ZiLong Liu Tsinghua University Beijing 100084 P.R.China Phone: +86-10-6278-5822 Email: liuzilong8266@126.com Yong Cui Tsinghua University Beijing 100084 P.R.China Phone: +86-10-62603059 Email: yong@csnet1.cs.tsinghua.edu.cn Authors' Addresses Jiang, Ed., et al. Expires July 7, 2017 [Page 19] Internet-Draft draft-ietf-softwire-map-radius-09 January 2017 Sheng Jiang Huawei Technologies Co., Ltd Q14, Huawei Campus, No.156 Beiqing Road Hai-Dian District, Beijing, 100095 P.R. China Email: jiangsheng@huawei.com Yu Fu CNNIC No.4 South 4th Street, Zhongguancun Hai-Dian District, Beijing, 100190 P.R. China Email: fuyu@cnnic.cn Bing Liu Huawei Technologies Co., Ltd Q14, Huawei Campus, No.156 Beiqing Road Hai-Dian District, Beijing, 100095 P.R. China Email: leo.liubing@huawei.com Peter Deacon IEA Software, Inc. P.O. Box 1170 Veradale, WA 99037 USA Email: peterd@iea-software.com Chongfeng Xie China Telecom Beijing P.R. China Email: xiechf@ctbri.com.cn Jiang, Ed., et al. Expires July 7, 2017 [Page 20] Internet-Draft draft-ietf-softwire-map-radius-09 January 2017 Tianxiang Li Tsinghua University Beijing 100084 P.R.China Email: peter416733@gmail.com Jiang, Ed., et al. Expires July 7, 2017 [Page 21]