--- 1/draft-ietf-radext-vlan-03.txt 2006-05-01 22:12:26.000000000 +0200 +++ 2/draft-ietf-radext-vlan-04.txt 2006-05-01 22:12:26.000000000 +0200 @@ -1,16 +1,16 @@ Network Working Group Paul Congdon INTERNET-DRAFT Mauricio Sanchez Category: Proposed Standard Hewlett-Packard Company - Bernard Aboba -12 April 2006 Microsoft Corporation + Bernard Aboba +29 April 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 @@ -21,21 +21,21 @@ 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 October 10, 2006. + This Internet-Draft will expire on November 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 in provisioning of access to IEEE 802 local @@ -49,27 +49,27 @@ 1.2 Requirements Language ........................... 3 1.3 Attribute Interpretation ........................ 3 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 ................................... 9 4. Diameter Considerations ............................... 9 5. IANA Considerations ................................... 9 -6. Security Considerations ............................... 9 +6. Security Considerations ............................... 10 7. References ............................................ 10 7.1 Normative References ............................ 10 7.2 Informative References .......................... 11 -ACKNOWLEDGMENTS .............................................. 11 +ACKNOWLEDGMENTS .............................................. 12 AUTHORS' ADDRESSES ........................................... 12 -Intellectual Property Statement............................... 12 +Intellectual Property Statement............................... 13 Disclaimer of Validity........................................ 13 Full Copyright Statement ..................................... 13 1. Introduction This document describes Virtual LAN (VLAN) and re-prioritization attributes that may prove useful for provisioning of access to IEEE 802 local area networks [IEEE-802] with the Remote Authentication Dialin User Service (RADIUS). @@ -90,42 +90,70 @@ A device that provides an access service for a user to a network. 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]. 1.3. Attribute Interpretation + The attributes described in this document apply to a single instance + of a NAS port, or more specifically an IEEE 802.1Q bridge port. + [IEEE-802.1Q] [IEEE-802.1D] and [IEEE-802.1X] do not recognize finer + management granularity than "per port". In some cases, such as with + IEEE 802.11 wireless LANs, the concept of a "virtual port" is used in + place of the physical port. Such virtual ports are typically based + on security associations and scoped by station, or MAC address. + + The attributes defined in this document are applied on per user basis + and it is expected that there is a single user per port; however in + some cases that port may be a "virtual port". If a NAS + implementation conforming to this document supports "virtual ports", + it may be possible to provision those "virtual ports" with unique + values of the attributes described in this document, allowing + multiple users sharing the same physical port to each have a unique + set of authorization parameters. + 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 Change of - Authorization Request (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. + [RFC3576] requires that a NAS receiving a Change of Authorization + Request (CoA-Request) reply with a CoA-NAK if the Request contains an + unsupported attribute. It is recommended that an Error-Cause + attribute with value set to "Unsupported Attribute" (401) be included + in the CoA-NAK. 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. + tagged or untagged frames as well as the VLANID. + + As defined in [RFC3580], the VLAN assigned via tunnel attributes + applies both to the ingress VLANID for untagged packets (known as + the PVID) and the egress VLANID for untagged packets. In + contrast, the Egress-VLANID attribute configures only the egress + VLANID for either tagged or untagged packets. The Egress-VLANID + attribute MAY be included in the same RADIUS packet as [RFC3580] + tunnel attributes; however, the Egress-VLANID attribute is not + necessary if it is being used to configure the same untagged + VLANID included in tunnel attributes. To configure an untagged + VLAN for both ingress and egress, the tunnel attrubutes of + [RFC3580] MUST be used. Multiple Egress-VLANID attributes MAY be included in Access- Request, Access-Accept, CoA-Request or Accounting-Request packets; 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: @@ -276,22 +304,22 @@ Bridges and MACs in the transmission path... Under normal circumstances, user priority is not modified in transit through the relay function of a Bridge; however, network management can control how user priority is propagated. Table 7-1 provides the ability to map incoming user priority values on a per-Port basis. By default, the regenerated user priority is identical to the incoming user priority. 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. + applied to frames arriving at this port. There are eight possible + user priorities, according to the [IEEE-802] standard. [IEEE-802.1D] clause 14.6.2.3.3 specifies the regeneration table as 8 values, each an integer in the range 0-7. The management variables are described in clause 14.6.2.2. A single User-Priority-Table attribute MAY be included in an Access-Accept or CoA-Request packet; this attribute MUST NOT be sent within an Access-Request, Access-Challenge, Access-Reject, Disconnect-Request, Disconnect-ACK, Disconnect-NAK, CoA-ACK, CoA- NAK or Accounting-Request. Since the regeneration table is only maintained by a bridge conforming to [IEEE-802.1D], this attribute @@ -319,21 +347,21 @@ 10 String The String field is 8 octets in length, and includes a table which maps the incoming priority (if it is set - 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. + frame. It is thus possible to either remap incoming priorities to more appropriate values; 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 @@ -396,21 +424,21 @@ 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 + quality of service (by downgrading user priority of frames arriving 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. @@ -434,21 +462,21 @@ 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. 7.2. Informative references -[IEEE802.1X] +[IEEE-802.1X] IEEE Standards for Local and Metropolitan Area Networks: Port based Network Access Control, IEEE Std 802.1X-2004, December 2004. [RFC2607] Aboba, B. and J. Vollbrecht, "Proxy Chaining and Policy Implementation in Roaming", RFC 2607, June 1999. [RFC2868] Zorn, G., Leifer, D., Rubens, A., Shriver, J., Holdrege, M. and I. Goyret, "RADIUS Attributes for Tunnel Protocol Support", RFC 2868, June 2000.