Network Working Group Dayong Guo Internet Draft Sheng Jiang Intended status: Standards Track Huawei Technologies Co., Ltd Expires: January 07, 2011 July 05, 2010 RADIUS Attribute for Softwire Concentrator in IPv6 Transition draft-guo-radext-softwire-concentrator-00.txt 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 January 07, 2011. Copyright Notice Copyright (c) 2010 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. Guo & Jiang Expires January 07, 2011 [Page 1] Internet-Draft draft-guo-radext-softwire-concentrator-00 July 2010 Abstract 6rd and DS-Lite are two most popular methods to provide both IPv4 and IPv6 connectivity services simultaneously during the IPv4/IPv6 co- existing period. Both mechanisms need to configure the softwire concentrator information on the host. In many networks, the information may be stored in AAA servers while user configuration is mainly through DHC protocol. This document defines several RADIUS attributes that carries softwire concentrator information. Table of Contents 1. Introduction.................................................3 2. Terminology..................................................3 3. Softwire Concentrator Configuration with RADIUS..............3 4. Attributes...................................................4 4.1. DS-Lite-Add Attribute...................................4 4.2. DS-Lite-Name Attribute..................................5 4.3. 6rd Attribute...........................................6 4.4. Table of attributes.....................................6 5. Diameter Considerations......................................7 6. Security Considerations......................................7 7. IANA Considerations..........................................7 8. Acknowledgments..............................................7 9. References...................................................8 9.1. Normative References....................................8 9.2. Informative References..................................8 Guo & Jiang Expires January 07, 2011 [Page 2] Internet-Draft draft-guo-radext-softwire-concentrator-00 July 2010 1. Introduction Recently providers start to deploy IPv6 and consider how to transit to IPv6. 6rd [I-D.ietf-softwire-ipv6-6rd] and DS-Lite [I-D.ietf-softwire-ds-lite] are two most popular methods to provide both IPv4 and IPv6 connectivity services simultaneously during the IPv4/IPv6 co-existing period. 6rd is used to provide IPv6 connectivity service through IPv4-only infrastructure while DS-Lite is aiming to provide IPv4 connectivity service through IPv6-only network. Both 6rd and DS-Lite adopt DHCP as auto-configuring protocol. In DS- lite, The DHCPv6 options are used to discover the IPv6 address or name of the AFTR (i.e. softwire concentrator) [I-D.ietf-softwire-ds-lite-tunnel-option]. Similarly the 6rd CPE extends DHCP option to discover 6rd border relay (i.e. softwire concentrator) and to configuring IPv6 address and prefix. In many networks, user configuration information may be managed by AAA servers, together with user Authentication, Authorization, and Accounting (AAA). Current AAA servers communicate using the RADIUS (Remote Authentication Dial In User Service, [RFC2865]) protocol. [I-D.ietf-radext-ipv6-access] describes a fixed line broadband network scenario in which the Broadband Network Gateways (BNGs) act as the access gateway of users (hosts or CPEs). The BNGs are assumed to embed a DHCPv6 server function that allows them to locally handle any DHCPv6 requests issued by hosts. Since the 6rd/DS-Lite softwire concentrator information is stored in AAA servers and user configuration is mainly through DHC protocol between BNGs and hosts. New RADIUS attributes are needed to propagate these information from AAA servers to BNGs. 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 [RFC2119]. 3. Softwire Concentrator Configuration with RADIUS The below Figure 1 illustrates how the RADIUS protocol and DHCPv6 are cooperated to provide users/hosts with DS-Lite configuration. 6rd has the same operation. Guo & Jiang Expires January 07, 2011 [Page 3] Internet-Draft draft-guo-radext-softwire-concentrator-00 July 2010 User/host BNG AAA Server | | | |----------Solicit-------->| | | |---Request (DS-Lite-Addr)--->| | | | | |<---Accept (DS-Lite-Addr)----| |<--------Advertise--------| | | | | |----------Request-------->| | | (DS-Lite tunnel Option) | | |<----------Reply----------| | | (DS-Lite tunnel option) | | | | | DHCPv6 RADIUS Figure 1: the cooperation between DHCPv6 and RADIUS BNGs act as a bridge between user and AAA server. First, a BNG receives a user DHCPv6 solicit. It initiates the BNG to request correspondent user authentication relevant from an AAA server using RADIUS protocol. A DS-Lite-Addr request may be also sent in the same message. If the user authentication is approved by the AAA server, an Accept message is acknowledged with the DS-Lite-Addr attribute, defined in the next Section. After the BNG responds to the user with an Advertise message, the user requests for a DS-Lite tunnel Option. Then, the BNG can reply the user using DHCPv6 protocol. 4. Attributes This section defines three RADIUS attributes that carries softwire concentrator information. DS-Lite-Addr Attribute and DS-Lite-Name Attribute can be used in DS-Lite scenario independently. 6rd Attribute should be used in the 6rd scenario. 4.1. DS-Lite-Add Attribute The DS-Lite-Add Attribute is structured as follows: Guo & Jiang Expires January 07, 2011 [Page 4] Internet-Draft draft-guo-radext-softwire-concentrator-00 July 2010 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 | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | | | DS-Lite tunnel-endpoint-addr (IPv6 Address) | | | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Type TBD1 Length 18 DS-Lite tunnel-endpoint-addr The address of DS-Lite is used to establish tunnel. In the DS-Lite scenarios the Address Family Transition Router element (AFTR) is an IPv6 address. 4.2. DS-Lite-Name Attribute The DS-Lite-Name 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 | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | | | Name of DS-Lite tunnel-endpoint (FQDN) | | | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Type TBD2 Length The length of the entire attribute, in bytes. Name of DS-Lite tunnel-endpoint The Fully Qualified Domain Name of softwire concentrator. In the DS-Lite scenarios, it is the domain name of Address Family Transition Router element (AFTR). Guo & Jiang Expires January 07, 2011 [Page 5] Internet-Draft draft-guo-radext-softwire-concentrator-00 July 2010 4.3. 6rd Attribute The 6rd 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 | IPv4MaskLen | 6rdPrefixLen | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | | 6rdPrefix | | | | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 6rdBRIPv4Address(es) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Type TBD3 Length the length of the DHCP option in octets (22 octets with one BR IPv4 address). IPv4MaskLen The number of high-order bits that are identical across all CE IPv4 addresses within a given 6rd domain. This may be any value between 0 and 32. Any value greater than 32 is invalid. 6rdPrefixLen The IPv6 Prefix length of the Service Provider's 6rd IPv6 prefix in number of bits. The 6rdPrefixLen MUST be less than or equal to 128. 6rdPrefix The Service Provider's 6rd IPv6 prefix represented as a 16 octet IPv6 address. The bits after the 6rdPrefixlen number of bits in the prefix SHOULD be set to zero. 6rdBRIPv4Address One or more IPv4 addresses of the 6rd Border Relay(s) for a given 6rd domain. 4.4. Table of attributes The following table provides a guide to which attributes may be found in which kinds of packets, and in what quantity. Guo & Jiang Expires January 07, 2011 [Page 6] Internet-Draft draft-guo-radext-softwire-concentrator-00 July 2010 Request Accept Reject Challenge Accounting # Attribute Request 0+ 0+ 0 0 0+ TBD1 DS-Lite-Addr 0+ 0+ 0 0 0+ TBD2 DS-Lite-Name 0+ 0+ 0 0 0+ TBD3 6rd 5. Diameter Considerations This attribute is usable within either RADIUS or Diameter [RFC3588]. Since the Attributes defined in this document will be allocated from the standard RADIUS type space, no special handling is required by Diameter entities. 6. Security Considerations In DS-Lite scenarios, the RADIUS protocol is run over IPv6. In 6rd scenarios, the RADIUS protocol is run over IPv4. Known security vulnerabilities of the RADIUS protocol are discussed in RFC 2607 [RFC2607], RFC 2865 [RFC2865], and RFC 2869 [RFC2869]. Use of IPsec [RFC4301] for providing security when RADIUS is carried in IPv6 is discussed in RFC 3162 [RFC3162]. Security considerations for the Diameter protocol are discussed in RFC 3588 [RFC3588]. 7. IANA Considerations This document requires the assignment of two new RADIUS Attribute Types in the "Radius Types" registry (currently located at http://www.iana.org/assignments/radius-types for the following attributes: o DS-Lite-Add o DS-Lite-Name o 6rd IANA should allocate these numbers from the standard RADIUS Attributes space using the "IETF Review" policy [RFC5226]. 8. Acknowledgments The authors would like to thank Maglione Roberta, Telecom Italia, for valuable comments. Guo & Jiang Expires January 07, 2011 [Page 7] Internet-Draft draft-guo-radext-softwire-concentrator-00 July 2010 9. Change Log [RFC Editor please remove] draft-guo-radext-softwire-concentrator-00, original version, 2010-07- 05. 10. References 10.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC2865] Rigney, C., Willens, S., Rubens, A., and W. Simpson, "Remote Authentication Dial In User Service (RADIUS)", RFC 2865, June 2000. [RFC3162] Aboba, B., Zorn, G., and D. Mitton, "RADIUS and IPv6", RFC 3162, August 2001. [RFC3588] Calhoun, P., Loughney, J., Guttman, E., Zorn, G., and J., Arkko, "Diameter Base Protocol", RFC 3588, September 2003. [RFC4301] Kent, S. and K. Seo, "Security Architecture for the Internet Protocol", RFC 4301, December 2005. [RFC5226] T. Narten, H. Alvestrand, "Guidelines for Writing an IANA Considerations Section in RFCs", RFC 5226, May 2008. 10.2. Informative References [RFC2607] Aboba, B. and J. Vollbrecht, "Proxy Chaining and Policy Implementation in Roaming", RFC 2607, June 1999. [RFC2869] Rigney, C., Willats, W., and P. Calhoun, "RADIUS Extensions", RFC 2869, June 2000. [I-D.ietf-radext-ipv6-access] Lourdelet, B., et al., "RADIUS attributes for IPv6 Access Networks", draft-ietf-radext- ipv6-access, work in progress, April 2010. [I-D.ietf-softwire-ds-lite] Durand A., et al., "Dual-stack lite broadband deployments post IPv4 exhaustion", draft-ietf- softwire-dual-stack-lite, work in progress, March 2010. Guo & Jiang Expires January 07, 2011 [Page 8] Internet-Draft draft-guo-radext-softwire-concentrator-00 July 2010 [I-D.ietf-softwire-ds-lite-tunnel-option] Hankins, D. and T. Mrugalski, "Dynamic Host Configuration Protocol for IPv6 (DHCPv6) Options for Dual-Stack Lite", draft-ietf-softwire- ds-lite-tunnel-option, work in progress, March 2010. [I-D.ietf-softwire-ipv6-6rd] Townsley W., et al., "IPv6 via IPv4 Service Provider Networks (6rd)", draft-ietf-softwire-ipv6- 6rd, (work in progress), March 2010. Author's Addresses Dayong Guo Huawei Technologies Co., Ltd Huawei Building, No.3 Xinxi Rd., Shang-Di Information Industry Base, Hai-Dian District, Beijing 100085 P.R. China Email: guoseu@huawei.com Sheng Jiang Huawei Technologies Co., Ltd Huawei Building, No.3 Xinxi Rd., Shang-Di Information Industry Base, Hai-Dian District, Beijing 100085 P.R. China Email: shengjiang@huawei.com Guo & Jiang Expires January 07, 2011 [Page 9]