Network Working Group J. Salowey Internet-Draft R. Droms Intended status: Standards Track Cisco Systems, Inc. Expires: April
13,19, 2007 October 10,16, 2006 RADIUS Delegated-IPv6-Prefix Attribute draft-ietf-radext-delegated-prefix-04.txtdraft-ietf-radext-delegated-prefix-05.txt Status of this Memo By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she becomes aware will be disclosed, in accordance with Section 6 of BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. 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." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on April 13,19, 2007. Copyright Notice Copyright (C) The Internet Society (2006). Abstract This document defines a RADIUS (Remote Authentication Dial In User Service) attribute that carries an IPv6 prefix that is to be delegated to the user. This attribute is usable within either RADIUS or Diameter. 1. Introduction This document defines the Delegated-IPv6-Prefix attribute as a RADIUS  attribute that carries an IPv6 prefix to be delegated to the user, for use in the user's network. For example, the prefix in a Delegated-IPv6-Prefix attribute can be delegated to another node through DHCP Prefix Delegation . The Delegated-IPv6-Prefix attribute can be used in DHCP Prefix Delegation between the delegating router and a RADIUS server, as illustrated in the following message sequence. RequetingRequesting Router Delegating Router RADIUS Server | | | |-Solicit------------>| | | |-Request------------------------>| | |<--Accept(Delegated-IPv6-Prefix)-| |<--Advertise(Prefix)-| | |-Request(Prefix)---->| | |<--Reply(Prefix)-----| | | | | DHCP PD RADIUS The Framed-IPv6-Prefix attribute  is not designed to support delegation of IPv6 prefixes to be used in the user's network, and therefore Framed-IPv6-Prefix and Delegated-IPv6-Prefix attributes may be included in the same RADIUS packet. 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 RFC 2119 . 3. Attribute format The format of the Delegated-IPv6-Prefix is: 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 | Reserved | Prefix-Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Prefix +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Prefix +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Prefix +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Prefix | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Type TBD for Delegated-IPv6-Prefix Length The length of the entire attribute, in bytes. At least 4 (to hold Type/Length/Reserved/Prefix-Length for a 0-bit prefix), and no larger than 20 (to hold Type/Length/ Reserved/Prefix-Length for a 128-bit prefix) Reserved Always set to zero by sender; ignored by receiver Prefix-Length The length of the prefix being delegated, in bits. At least 0 and no larger than 128 bits (identifying a single IPv6 address) Note that the prefix field is only required to be long enough to hold the prefix bits and can be shorter than 16 bytes. Any bits in the prefix field that are not part of the prefix MUST be zero. The Delegated-IPv6-Prefix MAY appear in an Access-Accept packet, and can appear multiple times. It MAY appear in an Access-Request packet as a hint by the NAS to the server that it would prefer these prefix(es), but the server is not required to honor the hint. The Delegated-IPv6-Prefix attribute MAY appear in an Accounting- Request packet. The Delegated-IPv6-Prefix MUST NOT appear in any other RADIUS packets. 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. +-----------------------------------------------------------------------+ | Request Accept Reject Challenge Accounting # Attribute | | Request | | 0+ 0+ 0 0 0+ TBD Delegated-IPv6-Prefix | +-----------------------------------------------------------------------+ The meaning of the above table entries is as follows: 0 This attribute MUST NOT be present. 0+ Zero or more instances of this attribute MAY be present. 0-1 Zero or one instance of this attribute MAY be present. 1 Exactly one instance of this attribute MUST be present. 1+ One or more of these attributes MUST be present. 5. Diameter Considerations When used in Diameter, the attribute defined in this specification can be used as a Diameter AVP from the Code space 1-255, i.e., RADIUS attribute compatibility space. No additional Diameter Code values are therefore allocated. The data types of the attributes are as follows: Delegated-IPv6-Prefix OctetString The attribute in this specification has no special translation requirements for Diameter to RADIUS or RADIUS to Diameter gateways, i.e., the attribute is copied as is, except for changes relating to headers, alignment, and padding. See also RFC 3588 , Section 4.1, and RFC 4005 , Section 9. The text in this specification describing the applicability of the Delegated-IPv6-Prefix attribute for RADIUS Access-Request applies in Diameter to AA-Request  or Diameter-EAP-Request . The text in this specification describing the applicability of the Delegated-IPv6-Prefix attribute for RADIUS Access-Accept applies in Diameter to AA-Answer or Diameter-EAP-Answer that indicates success. The text in this specification describing the applicability of the Delegated-IPv6-Prefix attribute for RADIUS Accounting-Request applies to Diameter Accounting-Request  as well. The AVP flag rules  for the Delegate-IPv6-PrefixDelegated-IPv6-Prefix attribute are: +---------------------+ | AVP Flag rules | |----+-----+----+-----|----+ AVP | | |SHLD| MUST| | Attribute Name Code Value Type |MUST| MAY | NOT| NOT|Encr| ---------------------------------|----+-----+----+-----|----| Delegated-IPv6- TBD OctetString| M | P | | V | Y | Prefix | | | | | | ---------------------------------|----+-----+----+-----|----| 6. IANA Considerations IANA is requested to assign a Type value, TBD, for this attribute from the RADIUS Attribute Types registry. 7. Security Considerations Known security vulnerabilities of the RADIUS protocol are discussed in RFC 2607 , RFC 2865  and RFC 2869 . Use of IPsec  for providing security when RADIUS is carried in IPv6 is discussed in RFC 3162. Security considerations for the Diameter protocol are discussed in RFC 3588 . 8. Change Log This section to be removed before publication as an RFC. The following changes were made in revision -01 of this document: o Added additional details to Abstract; defined that this attribute can be used in both RADIUS and Diameter. (Issue 188) o Moved and clarified text describing which packets this attribute can appear in adjacent to table in section 3. (Issue 188) o Fixed RFC 2119 boilerplate in section 2. (Issue 185) o Fixed table in section 3 to clarify which packets this attribute cannot appear in. (Issue 188) o Added section 4, Diameter Considerations. (Issue 188) o Made some references in section 6, Security Considerations, Informative rather than Normative. (Issue 188) o Updated reference to RFC 2401  to RFC 4301. (Issue 188) o Changed "IP SEC" to "IPsec" in section 6. (Issues 185 and 188) The following changes were made in revision -02 of this document: o Added a second paragraph to the Introduction, referencing the Framed-IPv6-Prefix attribute o Improved description of attribute fields in section 3 o Added border to table in section 3 o Updated Section 4, Diameter Considerations, to describe how this attribute would be used in Diameter. o Added reference to RFC 3588 in Section 6, Security Considerations. The following changes, based on Issues 201 and 204 on the RADEXT WG Issues list: http://www.drizzle.com/~aboba/RADEXT/, were made in revision -03 of this document: o Updated Section 5, Diameter Considerations, to describe the AVP flag rules for this attribute. o Edited Section 1, to clarify the relationship between the Delegated-IPv6-Prefix and Framed-IPv6-Prefix attributes. o Edited table of attributes and moved to a separate section. Revision -04 includes the following changes: o Editorial changes in the AVP flag rules table o Editorial changes in the description of the relationship between the Delegated-IPv6-Prefix and Framed-IPv6-Prefix attributes (last paragraph of section 1) o EditoricalEditorial changes in the first paragraph of section 1 to clarify that this document defines a new attribute not already defined in RFC 2865 o Added a text and a diagram to section 1 to illustrate the use of the Delegated-IPv6-Prefix attribute Revision -05 includes the following changes: o Corrected the spelling of "Reqesting" to "Requesting" in section 1, Introduction o Corrected the spelling of "Delegate-IPv6-Prefix" to "Delegated- IPv6-Prefix" in section 5, Diameter Consideration 9. References 9.1. Normative References  Rigney, C., Willens, S., Rubens, A., and W. Simpson, "Remote Authentication Dial In User Service (RADIUS)", RFC 2865, June 2000.  Troan, O. and R. Droms, "IPv6 Prefix Options for Dynamic Host Configuration Protocol (DHCP) version 6", RFC 3633, December 2003.  Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. 9.2. Non-normative References  Aboba, B., Zorn, G., and D. Mitton, "RADIUS and IPv6", RFC 3162, August 2001.  Calhoun, P., Loughney, J., Guttman, E., Zorn, G., and J. Arkko, "Diameter Base Protocol", RFC 3588, September 2003.  Calhoun, P., Zorn, G., Spence, D., and D. Mitton, "Diameter Network Access Server Application", RFC 4005, August 2005.  Eronen, P., Hiller, T., and G. Zorn, "Diameter Extensible Authentication Protocol (EAP) Application", RFC 4072, August 2005.  Aboba, B. and J. Vollbrecht, "Proxy Chaining and Policy Implementation in Roaming", RFC 2607, June 1999.  Rigney, C., Willats, W., and P. Calhoun, "RADIUS Extensions", RFC 2869, June 2000.  Kent, S. and K. Seo, "Security Architecture for the Internet Protocol", RFC 4301, December 2005. Authors' Addresses Joe Salowey Cisco Systems, Inc. 2901 Third Avenue Seattle, WA 98121 USA Phone: +1 206.310.0596 Email: email@example.com Ralph Droms Cisco Systems, Inc. 1414 Massachusetts Avenue Boxborough, MA 01719 USA Phone: +1 978.936.1674 Email: firstname.lastname@example.org Full Copyright Statement Copyright (C) The Internet Society (2006). This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights. This document and the information contained herein are provided on an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Intellectual Property The IETF takes no position regarding the validity or scope of any Intellectual Property Rights or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; nor does it represent that it has made any independent effort to identify any such rights. Information on the procedures with respect to rights in RFC documents can be found in BCP 78 and BCP 79. Copies of IPR disclosures made to the IETF Secretariat and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementers or users of this specification can be obtained from the IETF on-line IPR repository at http://www.ietf.org/ipr. The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights that may cover technology that may be required to implement this standard. Please address the information to the IETF at email@example.com. Acknowledgment Funding for the RFC Editor function is provided by the IETF Administrative Support Activity (IASA).