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Versions: 00 01 02 03 04 05 06 rfc4675                                  
Network Working Group                                       Paul Congdon
INTERNET-DRAFT                                          Mauricio Sanchez
Category: Proposed Standard                      Hewlett-Packard Company
<draft-ietf-radext-vlan-01.txt>                            Bernard Aboba
22 March 2006                                      Microsoft Corporation


         RADIUS Attributes for Virtual LAN and Priority Support

   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
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   Drafts.

   Internet-Drafts are draft documents valid for a maximum of six months
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   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 September 10, 2006.

Copyright Notice

   Copyright (C) The Internet Society 2006.

Abstract

   This document proposes additional RADIUS (Remote Authentication Dial
   In User Service) attributes for dynamic Virtual LAN assignment and
   prioritization, for use by IEEE 802.1X authenticators.  These
   attributes are usable within either RADIUS or Diameter.









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Table of Contents

1.     Introduction ..........................................    3
   1.1       Terminology .....................................    3
   1.2       Requirements Language ...........................    3
   1.3       Attribute Interpretation ........................    4
2.     Attributes ............................................    4
   2.1       Egress-VLANID ...................................    4
   2.2       Ingress-Filters .................................    5
   2.3       Egress-VLAN-Name ................................    6
   2.4       User-Priority-Table .............................    7
3.     Table of Attributes ...................................    8
4.     Diameter Considerations ...............................    9
5.     IANA Considerations ...................................    9
6.     Security Considerations ...............................    9
7.     References ............................................   10
   7.1       Normative References ............................   10
   7.2       Informative References ..........................   10
ACKNOWLEDGMENTS ..............................................   12
AUTHORS' ADDRESSES ...........................................   12
Intellectual Property Statement...............................   13
Disclaimer of Validity........................................   13
Full Copyright Statement .....................................   13




























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1.  Introduction

   IEEE 802.1X [IEEE-802.1X] provides "network port authentication" for
   IEEE 802 [IEEE-802] media, including Ethernet [IEEE-802.3], Token
   Ring and 802.11 wireless LANs [IEEE-802.11i].

   This document describes Virtual LAN (VLAN) and re-prioritization
   attributes that may prove useful for provisioning of access to IEEE
   802 local area networks with the Remote Authentication Dialin User
   Service (RADIUS).

   While [RFC3580] enables support for VLAN assignment based on the
   tunnel attributes defined in [RFC2868], it does not provide support
   for a more complete set of VLAN functionality as defined by
   [IEEE-802.1Q].  The attributes defined in this document provide
   support within RADIUS analogous to the management variables supported
   in [IEEE-802.1Q] and MIB objects defined in [RFC4363].  In addition,
   this document enables support for a wider range of [IEEE-802.1X]
   configurations.

1.1.  Terminology

This document uses the following terms:

Authenticator
     The end of the link initiating EAP authentication.  The term
     authenticator is used in [RFC3748] and [IEEE-802.1X], and has the
     same meaning in this document.

backend authentication server
     A backend authentication server is an entity that provides an
     authentication service to an authenticator.  When used, this server
     typically executes EAP methods for the authenticator.  This
     terminology is also used in [IEEE-802.1X].

Network Access Server (NAS)
     A device that provides an access service for a user to a network.

Supplicant
     The end of the link that responds to the authenticator in
     [IEEE-802.1X].

1.2.  Requirements Language

   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].




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1.3.  Attribute Interpretation

   If a NAS conforming to this specification receives an Access-Accept
   packet containing an attribute defined in this document which it
   cannot apply, it MUST act as though it had received an Access-Reject.

   Similarly, [RFC3576] requires that a NAS receiving a  CoA-Request
   containing an unsupported attribute reply with a CoA-NAK.  It is
   recommended that an Error-Cause attribute with value set to
   "Unsupported Attribute" (401) be included in the packet.  As noted in
   [RFC3576], authorization changes are atomic so that this situation
   does not result in session termination and the pre-existing
   configuration remains unchanged.  As a result, no accounting packets
   should be generated.

2.  Attributes

2.1.  Egress-VLANID

   Description

      The Egress-VLANID attribute represents an allowed IEEE 802 Egress
      VLANID for this port, indicating if the VLANID is allowed for
      tagged or untagged packets as well as the VLANID.

      Multiple Egress-VLANID attributes MAY be included in an Access-
      Request, Access-Accept or CoA-Request packet; this attribute MUST
      NOT be sent within an Access-Challenge, Access-Reject, Disconnect-
      Request, Disconnect-ACK, Disconnect-NAK, CoA-ACK, or CoA-NAK.
      Each attribute adds the specified VLAN to the list of allowed
      egress VLANs for the port.

      The Egress-VLANID attribute is shown below.  The fields are
      transmitted from left to right:

       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     |            Integer
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
              Integer                 |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type

      TBD

   Length



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      6

   Integer

      The Integer field is four octets in length.  The format is
      described below:

       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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |  Tag Indic.   |        Pad            |       VLANID          |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

      The Tag Indication field is one octet in length, and indicates
      whether the frames on the VLAN are tagged (0x31) or untagged
      (0x32).  The Pad field is 12-bits in length and MUST be 0 (zero).
      The VLANID is 12-bits in length and contains the [IEEE-802.1Q]
      VLAN VID value.

2.2.  Ingress-Filters

   Description

      The Ingress-Filters attribute corresponds to Ingress Filter per-
      port variable defined in [IEEE-802.1Q] clause 8.4.5.  When the
      attribute has the value "Enabled", the set of VLANs that are
      allowed to ingress a port must match the set of VLANs that are
      allowed to egress a port.  Only a single Ingress-Filters attribute
      MAY be sent within an Access-Request, Access-Accept or CoA-Request
      packet; this attribute MUST NOT be sent within an Access-
      Challenge, Access-Reject, Disconnect-Request, Disconnect-ACK,
      Disconnect-NAK, CoA-ACK, or CoA-NAK.

      The Ingress-Filters attribute is shown below.  The fields are
      transmitted from left to right:

       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     |         Integer
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
             Integer                  |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type

      TBD




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   Length

      6

   Integer

      Supported values include:

      1 - Enabled
      2 - Disabled

2.3.  Egress-VLAN-Name

   Description

      Clause 12.10.2.1.3 (a) in [IEEE-8021.Q] describes the
      administratively assigned VLAN Name associated with a VLAN-ID
      defined within an IEEE 802.1Q bridge. The Egress-VLAN-Name
      attribute represents an allowed VLAN for this port.  It is similar
      to the Egress-VLANID attribute, except that the VLAN-ID itself is
      not specified or known; rather the VLAN name is used to identify
      the VLAN within the system.

      The Egress-VLAN-Name attribute contains two parts; the first part
      indicates if frames on the VLAN for this port are to be
      represented in tagged or untagged format, the second part is the
      VLAN name.

      Multiple Egress-VLAN-Name attributes MAY be included within an
      Access-Request, Access-Accept or CoA-Request packet; this
      attribute MUST NOT be sent within an Access-Challenge, Access-
      Reject, Disconnect-Request, Disconnect-ACK, Disconnect-NAK, CoA-
      ACK, or CoA-NAK.  Each attribute adds the named VLAN to the list
      of allowed egress VLANs for the port.  The Egress-VLAN-Name
      attribute is shown below.  The fields are transmitted from left to
      right:

       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     |   Tag Indic.  |   String...
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


   Type

      TBD




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   Length

      >=4

   Tag Indication

      The Tag Indication field is one octet in length, and indicates
      whether the frames on the VLAN are tagged (0x31) or untagged
      (0x32).

   String

      The String field is at least one octet in length, and contains the
      the VLAN Name as defined in [IEEE-802.1Q] clause 12.10.2.1.3 (a).
      [RFC3629] UTF-8 encoded 10646 characters are RECOMMENDED, but a
      robust implementation SHOULD support the field as undistinguished
      octets.

2.4.  User-Priority-Table

   Description

      [IEEE-802.1D] clause 7.5.1 discusses how to regenerate (or re-map)
      user priority on frames received at a port.  This per-port
      configuration enables a bridge to cause the priority of received
      traffic at a port to be mapped to a particular priority.  The
      management variables are described in clause 14.6.2.2.

      This attribute represents the IEEE 802 prioritization that will be
      applied to packets arriving at this port.  There are eight
      possible user priorities, according to the [IEEE-802] standard.  A
      single User-Priority-Table attribute MAY be included in an Access-
      Request, Access-Accept or CoA-Request packet; this attribute MUST
      NOT be sent within an Access-Challenge, Access-Reject, Disconnect-
      Request, Disconnect-ACK, Disconnect-NAK, CoA-ACK, or CoA-NAK.

      The User-Priority-Table attribute is shown below.  The fields are
      transmitted from left to right:

       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       |          String
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
                                    String
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
                    String            |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+



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   Type

      TBD

   Length

      10

   String

      The String field is 8 octets in length, and includes a table which
      maps the incoming priority (if one exists - the default is 0) into
      one of eight regenerated priorities.  The first octet maps to
      incoming priority 0, the second octet to incoming priority 1, etc.
      The values in each octet represent the regenerated priority of the
      packet.

      It is thus possible to either remap incoming priorities to more
      appropriate values; or to honor the incoming priorities; or to
      override any incoming priorities, forcing them to all map to a
      single chosen priority.

      The [IEEE-8021.D] specification, Annex G, provides a useful
      description of traffic type - traffic class mappings.

3.  Table of Attributes

   The following table provides a guide to which attributes may be found
   in which kinds of packets, and in what quantity.

   Access-   Access-  Access-  Access-    CoA-
   Request   Accept   Reject   Challenge  Req     #    Attribute
      0+        0+       0        0        0+    TBD  Egress-VLANID
      0-1       0-1      0        0        0-1   TBD  Ingress-Filters
      0+        0+       0        0        0+    TBD  Egress-VLAN-Name
      0-1       0-1      0        0        0-1   TBD  User-Priority-Table

   The following table defines the meaning of the above table entries.

     0     This attribute MUST NOT be present in the packet.
     0+    Zero or more instances of this attribute MAY be
           present in the packet.
     0-1   Zero or one instance of this attribute MAY be
           present in the packet.







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4.  Diameter Considerations

   Diameter needs to define identical attributes with the same Type
   values.  The attributes should be available as part of the NASREQ
   application [RFC4005], as well as the Diameter EAP application
   [RFC4072].

5.  IANA Considerations

   This specification does not create any new registries.

   This document uses the RADIUS [RFC2865] namespace, see
   <http://www.iana.org/assignments/radius-types>.  Allocation of four
   updates for the section "RADIUS Attribute Types" is requested. The
   RADIUS attributes for which values are requested are:

   TBD - Egress-VLANID
   TBD - Ingress-Filters
   TBD - Egress-VLAN-Name
   TBD - User-Priority-Table

6.  Security Considerations

   This specification describes the use of RADIUS for purposes of
   authentication, authorization and accounting in networks supporting
   [IEEE 802.1X].   Threats and security issues for this application are
   described in [RFC3579] and [RFC3580]; security issues encountered in
   roaming are described in [RFC2607].

   This document specifies new attributes that can be included in
   existing RADIUS packets, which are protected as described in
   [RFC3579] and [RFC3576].  See those documents for a more detailed
   description.

   The security mechanisms described in [RFC3579] and [RFC3576] are
   focused on preventing an attacker from spoofing packets or modifying
   packets in transit.  They do not prevent an authorized RADIUS server
   or proxy from inserting attributes with malicious intent.

   VLAN attributes sent by a RADIUS server or proxy may enable access to
   unauthorized VLANs.  These vulnerabilities can be limited by
   performing authorization checks at the NAS.  For example, a NAS can
   be configured to accept only certain VLANIDs from a given RADIUS
   server/proxy.

   Similarly, an attacker gaining control of a RADIUS server or proxy
   can modify the user priority table, causing either degradation of
   quality of service (by downgrading user priority of packets arriving



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   at a port), or denial of service (by raising the level of priority of
   traffic at multiple ports of a device, oversubscribing the switch or
   link capabilities).

7.  References

7.1.  Normative references

[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
          Requirement Levels", RFC 2119, March, 1997.

[RFC2865] Rigney, C., Rubens, A., Simpson, W. and S. Willens, "Remote
          Authentication Dial In User Service (RADIUS)", RFC 2865, June
          2000.

[RFC3575] Aboba, B., "IANA Considerations for RADIUS", RFC 3575, July
          2003.

[RFC3629] Yergeau, F., "UTF-8, a transformation of ISO 10646", RFC 2607,
          November 2003.

[RFC4363] Levi, D. and D. Harrington, "Definitions of Managed Objects
          for Bridges with Traffic Classes, Multicast Filtering and
          Virtual LAN Extensions", RFC 4363, January 2006.

[IEEE-802]
          IEEE Standards for Local and Metropolitan Area Networks:
          Overview and Architecture, ANSI/IEEE Std 802, 1990.

[IEEE-802.1D]
          IEEE Standards for Local and Metropolitan Area Networks: Media
          Access Control (MAC) Bridges, IEEE Std 802.1D-2004, June 2004.

[IEEE-802.1Q]
          IEEE Standards for Local and Metropolitan Area Networks: Draft
          Standard for Virtual Bridged Local Area Networks,
          P802.1Q-2003, January 2003.

[IEEE-802.1X]
          IEEE Standards for Local and Metropolitan Area Networks: Port
          based Network Access Control, IEEE Std 802.1X-2004, August
          2004.

7.2.  Informative references

[RFC2607] Aboba, B. and J. Vollbrecht, "Proxy Chaining and Policy
          Implementation in Roaming", RFC 2607, June 1999.




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[RFC2868] Zorn, G., Leifer, D., Rubens, A., Shriver, J., Holdrege, M.
          and I. Goyret, "RADIUS Attributes for Tunnel Protocol
          Support", RFC 2868, June 2000.

[RFC3576] Chiba, M., Dommety, G., Eklund, M., Mitton, D. and B.  Aboba,
          "Dynamic Authorization Extensions to Remote Authentication
          Dial In User Service (RADIUS)", RFC 3576, July 2003.

[RFC3579] Aboba, B. and P. Calhoun, "RADIUS Support for Extensible
          Authentication Protocol (EAP)", RFC 3579, September 2003.

[RFC3580] Congdon, P., Aboba, B., Smith, A., Zorn, G., Roese, J., "IEEE
          802.1X Remote Authentication Dial In User Service (RADIUS)
          Usage Guidelines", RFC3580, September 2003.

[RFC3748] Aboba, B., Blunk, L., Vollbrecht, J., Carlson, J. and H.
          Levkowetz, "Extensible Authentication Protocol (EAP)", RFC
          3748, June 2004.

[RFC4005] Calhoun, P., Zorn, G., Spence, D. and D. Mitton, "Diameter
          Network Access Server Application", RFC 4005, August 2005.

[RFC4072] Eronen, P., Hiller, T., and G. Zorn, "Diameter Extensible
          Authentication Protocol (EAP) Application", RFC 4072, August
          2005.

[IEEE-802.3]
          ISO/IEC 8802-3 Information technology - Telecommunications and
          information exchange between systems - Local and metropolitan
          area networks - Common specifications - Part 3:  Carrier Sense
          Multiple Access with Collision Detection (CSMA/CD) Access
          Method and Physical Layer Specifications, (also ANSI/IEEE Std
          802.3- 1996), 1996.

[IEEE-802.11]
          Information technology - Telecommunications and information
          exchange between systems - Local and metropolitan area
          networks - Specific Requirements Part 11:  Wireless LAN Medium
          Access Control (MAC) and Physical Layer (PHY) Specifications,
          IEEE Std. 802.11-1999, 1999.

[IEEE-802.11i]
          Institute of Electrical and Electronics Engineers, "Supplement
          to Standard for Telecommunications and Information Exchange
          Between Systems - LAN/MAN Specific Requirements - Part 11:
          Wireless LAN Medium Access Control (MAC) and Physical Layer
          (PHY) Specifications: Specification for Enhanced Security",
          June 2004.



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Acknowledgments

   The authors would like to acknowledge Joseph Salowey of Cisco, David
   Nelson of Enterasys, Chuck Black of Hewlett Packard, and Ashwin
   Palekar of Microsoft.

Authors' Addresses

   Paul Congdon
   Hewlett Packard Company
   HP ProCurve Networking
   8000 Foothills Blvd, M/S 5662
   Roseville, CA  95747

   EMail: paul.congdon@hp.com
   Phone: +1 916 785 5753
   Fax:   +1 916 785 8478

   Mauricio Sanchez
   Hewlett Packard Company
   HP ProCurve Networking
   8000 Foothills Blvd, M/S 5559
   Roseville, CA  95747

   EMail: mauricio.sanchez@hp.com
   Phone: +1 916 785 1910
   Fax:   +1 916 785 1815

   Bernard Aboba
   Microsoft Corporation
   One Microsoft Way
   Redmond, WA 98052

   EMail: bernarda@microsoft.com
   Phone: +1 425 706 6605
   Fax:   +1 425 936 7329















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Intellectual Property Statement

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Disclaimer of Validity

   This document and the information contained herein are provided on an
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   ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED,
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   WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.

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.

Acknowledgment

   Funding for the RFC Editor function is currently provided by the
   Internet Society.







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Open issues

   Open issues relating to this specification are tracked on the
   following web site:

   http://www.drizzle.com/~aboba/RADEXT/













































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