draft-ietf-dhc-dhcpv6-radius-opt-11.txt   draft-ietf-dhc-dhcpv6-radius-opt-12.txt 
DHC Working Group L. Yeh DHC Working Group L. Yeh
Internet-Draft Freelancer Technologies Internet-Draft Freelancer Technologies
Intended status: Standards Track M. Boucadair Intended status: Standards Track M. Boucadair
Expires: October 14, 2013 France Telecom Expires: November 19, 2013 France Telecom
April 12, 2013 May 18, 2013
RADIUS Option for DHCPv6 Relay Agent RADIUS Option for DHCPv6 Relay Agent
draft-ietf-dhc-dhcpv6-radius-opt-11 draft-ietf-dhc-dhcpv6-radius-opt-12
Abstract Abstract
The DHCPv6 RADIUS option provides a mechanism to exchange The DHCPv6 RADIUS option provides a mechanism to exchange
authorization and identification information between the DHCPv6 relay authorization and identification information between the DHCPv6 relay
agent and the DHCPv6 server. This mechanism is meant for the agent and the DHCPv6 server. This mechanism is meant for the
centralized DHCPv6 server to select the right configuration for the centralized DHCPv6 server to select the right configuration for the
requesting DHCPv6 client based on the authorization information requesting DHCPv6 client based on the authorization information
received from the RADIUS server, which is not co-located with the received from the RADIUS server, which is not co-located with the
DHCPv6 server. The Network Access Server (NAS) acts as DHCPv6 relay DHCPv6 server. The Network Access Server (NAS) acts as DHCPv6 relay
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This Internet-Draft will expire on October 14, 2013. This Internet-Draft will expire on November 19, 2013.
Copyright Notice Copyright Notice
Copyright (c) 2013 IETF Trust and the persons identified as the Copyright (c) 2013 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of (http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
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include Simplified BSD License text as described in Section 4.e of include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Terminology and Language . . . . . . . . . . . . . . . . . . . 3 2. Terminology and Language . . . . . . . . . . . . . . . . . . . 3
3. Network Scenarios . . . . . . . . . . . . . . . . . . . . . . 4 3. Network Scenarios . . . . . . . . . . . . . . . . . . . . . . 4
4. DHCPv6 RADIUS option . . . . . . . . . . . . . . . . . . . . . 7 4. DHCPv6 RADIUS option . . . . . . . . . . . . . . . . . . . . . 7
4.1. RADIUS attributes permitted in DHCPv6 RADIUS option . . . 7 4.1. RADIUS attributes permitted in DHCPv6 RADIUS option . . . 8
5. DHCPv6 Relay Agent Behavior . . . . . . . . . . . . . . . . . 8 5. DHCPv6 Relay Agent Behavior . . . . . . . . . . . . . . . . . 8
6. DHCPv6 Server Behavior . . . . . . . . . . . . . . . . . . . . 8 6. DHCPv6 Server Behavior . . . . . . . . . . . . . . . . . . . . 8
7. DHCPv6 Client Behavior . . . . . . . . . . . . . . . . . . . . 8 7. DHCPv6 Client Behavior . . . . . . . . . . . . . . . . . . . . 8
8. Security Considerations . . . . . . . . . . . . . . . . . . . 8 8. Security Considerations . . . . . . . . . . . . . . . . . . . 9
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9
10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 9 10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 9
11. References . . . . . . . . . . . . . . . . . . . . . . . . . . 9 11. References . . . . . . . . . . . . . . . . . . . . . . . . . . 10
11.1. Normative References . . . . . . . . . . . . . . . . . . . 9 11.1. Normative References . . . . . . . . . . . . . . . . . . . 10
11.2. Informative References . . . . . . . . . . . . . . . . . . 10 11.2. Informative References . . . . . . . . . . . . . . . . . . 10
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 10 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 11
1. Introduction 1. Introduction
DHCPv6 provides a mechanism that allows the server to assign or DHCPv6 provides a mechanism that allows the server to assign or
delegate both stateful and stateless configuration parameters to the delegate both stateful and stateless configuration parameters to the
clients. The stateful configuration parameters include IPv6 address clients. The stateful configuration parameters include IPv6 address
[RFC3315] and IPv6 prefix [RFC3633]. The stateless configuration [RFC3315] and IPv6 prefix [RFC3633]. The stateless configuration
parameters [RFC3736] include, for example, DNS [RFC3646], or a FQDN parameters [RFC3736] include, for example, DNS [RFC3646], or a FQDN
of AFTR [RFC6334]. In the scenarios described in this document, the of AFTR [RFC6334]. In the scenarios described in this document, the
DHCPv6 server is deployed in the central part of an ISP network. DHCPv6 server is deployed in the central part of an ISP network.
RADIUS [RFC2865] is widely used as the centralized authentication, RADIUS [RFC2865] is widely used as the centralized authentication,
authorization and user management mechanism for the service provision authorization and user management mechanism for the service provision
in Broadband access network. [RFC3162], [RFC4818], [RFC6519] and in Broadband access network. [RFC3162], [RFC4818], [RFC6519] and
[I-D.ietf-radext-ipv6-access] specified attributes that support the [RFC6911] specified attributes that support the service provision for
service provision for IPv6-only and IPv6-transition access. RADIUS IPv6-only and IPv6-transition access. RADIUS server authorizes the
server authorizes the Network Access Server (NAS) to assign an IPv6 Network Access Server (NAS) to assign an IPv6 address or prefix from
address or prefix from the indicated pool, or to assign an IPv6 the indicated pool, or to assign an IPv6 address or prefix with an
address or prefix with an explicitly indicated value, and other explicitly indicated value, and other configuration parameters as per
configuration parameters as per the attributes for the subscribers. the attributes for the subscribers.
These mechanisms work well in the deployment scenarios where the NAS These mechanisms work well in the deployment scenarios where the NAS
acts as the distributed DHCPv6 server. In that case the NAS directly acts as the distributed DHCPv6 server. In that case the NAS directly
responds the DHCPv6 messages as per the indication conveyed by the responds the DHCPv6 messages as per the indication conveyed by the
attributes in the Access-Accept message from the RADIUS server. attributes in the Access-Accept message from the RADIUS server.
These mechanisms might also work well in the scenario where the These mechanisms might also work well in the scenario where the
centralized DHCPv6 server is co-located with the RADIUS server, where centralized DHCPv6 server is co-located with the RADIUS server, where
they can share the same database of the users. But when the NAS acts they can share the same database of the users. But when the NAS acts
as the relay agent and RADIUS client simultaneously, and the as the relay agent and RADIUS client simultaneously, and the
centralized DHCPv6 server is not located in the same place as the centralized DHCPv6 server is not located in the same place as the
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| option-data (List of RADIUS Attributes) | option-data (List of RADIUS Attributes)
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
option-code TBD option-code TBD
option-len Length of the option-data in octets option-len Length of the option-data in octets
option-data List of one or more RADIUS attributes option-data List of one or more RADIUS attributes
The option-data of OPTION_RADIUS is a list of one or more RADIUS The option-data of OPTION_RADIUS is a list of one or more RADIUS
attributes received in the Access-Accept message from the RADIUS attributes received in the Access-Accept message from the RADIUS
server. The OPTION_RADIUS can only contain the RADIUS attributes server. The format of RADIUS attributes is defined in section 5 of
[RFC2865]. The OPTION_RADIUS can only contain the RADIUS attributes
listed in the IANA Registry of 'RADIUS attributes permitted in DHCPv6 listed in the IANA Registry of 'RADIUS attributes permitted in DHCPv6
RADIUS option'. RADIUS option'.
According to the network scenarios described in section 3, the According to the network scenarios described in section 3, the
OPTION_RADIUS SHOULD appear in the RELAY-FORW (12) message relaying OPTION_RADIUS SHOULD appear in the RELAY-FORW (12) message relaying
SOLICIT (1), REQUEST (3) and REBIND (6) from the DHCPv6 client, and SOLICIT (1), REQUEST (3) and REBIND (6) from the DHCPv6 client, and
MAY appear in the RELAY-FORW (12) relaying any other message from the MAY appear in the RELAY-FORW (12) relaying any other message from the
DHCPv6 client. DHCPv6 client.
4.1. RADIUS attributes permitted in DHCPv6 RADIUS option 4.1. RADIUS attributes permitted in DHCPv6 RADIUS option
The RADIUS attributes listed in the below table are recommended as The RADIUS attributes listed in the below table are recommended as
the first batch of attributes in the IANA Registry of 'RADIUS the first batch of attributes in the IANA Registry of 'RADIUS
attributes permitted in DHCPv6 RADIUS option'. New RADIUS attributes attributes permitted in DHCPv6 RADIUS option'. New RADIUS attributes
MAY be added to this list after the IETF Expert Review [RFC5226]. can be added to this list after Expert Review [RFC5226].
Type Code Attribute Reference Type Code Attribute Reference
26 Vendor-Specific [RFC2865] 26 Vendor-Specific [RFC2865]
123 Delegated-IPv6-Prefix [RFC4818] 123 Delegated-IPv6-Prefix [RFC4818]
144 DS-Lite-Tunnel-Name [RFC6519] 144 DS-Lite-Tunnel-Name [RFC6519]
168 Framed-IPv6-Address [I-D.ietf-radext-ipv6-access] 168 Framed-IPv6-Address [RFC6911]
169 DNS-Server-IPv6-Address [I-D.ietf-radext-ipv6-access] 169 DNS-Server-IPv6-Address [RFC6911]
171 Delegated-IPv6-Prefix-Pool [I-D.ietf-radext-ipv6-access] 171 Delegated-IPv6-Prefix-Pool [RFC6911]
172 Stateful-IPv6-Address-Pool [I-D.ietf-radext-ipv6-access] 172 Stateful-IPv6-Address-Pool [RFC6911]
Note: The RADIUS attribute's 'Length' defined in section 5 of Note: The RADIUS attribute's 'Length' defined in section 5 of
[RFC2865] includes the length of 'Type' and 'Length' fields. [RFC2865] includes the length of 'Type' and 'Length' fields.
5. DHCPv6 Relay Agent Behavior 5. DHCPv6 Relay Agent Behavior
The DHCPv6 relay agent MAY include OPTION_RADIUS in the RELAY-FORW The DHCPv6 relay agent MAY include OPTION_RADIUS in the RELAY-FORW
(12) message. When the value in the attributes, for example, (12) message. When the value in the attributes, for example,
Delegated-IPv6-Prefix-Pool (171), Stateful-IPv6-Address-Pool (172), Delegated-IPv6-Prefix-Pool (171), Stateful-IPv6-Address-Pool (172),
Delegated-IPv6-Prefix (123) or Framed-IPv6-Address (168) in the Delegated-IPv6-Prefix (123) or Framed-IPv6-Address (168) in the
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The mechanism described in this document may introduce new attack The mechanism described in this document may introduce new attack
vector against the DHCPv6 server in case the DHCPv6 relay agent is vector against the DHCPv6 server in case the DHCPv6 relay agent is
compromised. By forging the RADIUS attributes contained in the compromised. By forging the RADIUS attributes contained in the
OPTION_RADIUS of the RELAY-FORW (12) messages, the attacker may OPTION_RADIUS of the RELAY-FORW (12) messages, the attacker may
influence the parameter assignment on the DHCPv6 server for the influence the parameter assignment on the DHCPv6 server for the
DHCPv6 clients. However, in the network scenarios described in the DHCPv6 clients. However, in the network scenarios described in the
section 3, NAS could always be regarded as a trusted network section 3, NAS could always be regarded as a trusted network
component in the real deployment. component in the real deployment.
Network administrators should be aware that although RADIUS messages
are encrypted, DHCPv6 messages can not be encrypted. It is possible
that some RADIUS vendor-specific attributes might contain the
sensitive or confidential information. Network administrators are
strongly advised to prevent including such information into DHCPv6
messages.
9. IANA Considerations 9. IANA Considerations
This document requests to assign a new DHCPv6 option code for This document requests to assign a new DHCPv6 option code for
OPTION_RADIUS defined in section 4, and to create a new registry on OPTION_RADIUS defined in section 4, and to create a new registry on
the same assignment page, which is entitled as 'RADIUS attributes the same assignment page, which is entitled as 'RADIUS attributes
permitted in DHCPv6 RADIUS option' defined in section 4.1. The new permitted in DHCPv6 RADIUS option' defined in section 4.1. The new
registry will enumerate the RADIUS Attributes Types registry will enumerate the RADIUS Attributes Types
(http://www.iana.org/assignments/radius-types/radius-types.xml) that (http://www.iana.org/assignments/radius-types/radius-types.xml) that
are permitted to be included in the DHCPv6 RADIUS option. New RADIUS are permitted to be included in the DHCPv6 RADIUS option. The
attributes MAY be added to this list after the IETF Expert Review allocation policy of this 'RADIUS attributes permitted in DHCPv6
[RFC5226]. The IETF expert review SHOULD include careful RADIUS option' registry is Expert Review [RFC5226]. Designated
consideration of the security implications of allowing the relay expert should carefully consider the security implications of
agent to include the RADIUS attribute being considered for addition allowing the relay agent to include new RADIUS attribute for the
to this registry. addition to this registry.
10. Acknowledgements 10. Acknowledgements
Thanks to Tomek Mrugalski, Bernie Volz, Gaurav Halwasia and Roberta Thanks to Tomek Mrugalski, Bernie Volz, Gaurav Halwasia and Roberta
Maglione for their thorough review comments in the mailing list of Maglione for their thorough review comments in the mailing list of
DHC working group, to Ted Lemon for his continuous encouragement and DHC working group, to Ted Lemon for his continuous encouragement and
technical guidance. technical guidance.
11. References 11. References
11.1. Normative References 11.1. Normative References
[I-D.ietf-radext-ipv6-access]
Dec, W., Sarikaya, B., Zorn, G., Miles, D., and B.
Lourdelet, "RADIUS attributes for IPv6 Access Networks",
draft-ietf-radext-ipv6-access-16 (work in progress),
February 2013.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997. Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2865] Rigney, C., Willens, S., Rubens, A., and W. Simpson, [RFC2865] Rigney, C., Willens, S., Rubens, A., and W. Simpson,
"Remote Authentication Dial In User Service (RADIUS)", "Remote Authentication Dial In User Service (RADIUS)",
RFC 2865, June 2000. RFC 2865, June 2000.
[RFC3315] Droms, R., Bound, J., Volz, B., Lemon, T., Perkins, C., [RFC3315] Droms, R., Bound, J., Volz, B., Lemon, T., Perkins, C.,
and M. Carney, "Dynamic Host Configuration Protocol for and M. Carney, "Dynamic Host Configuration Protocol for
IPv6 (DHCPv6)", RFC 3315, July 2003. IPv6 (DHCPv6)", RFC 3315, July 2003.
skipping to change at page 10, line 26 skipping to change at page 10, line 30
[RFC4818] Salowey, J. and R. Droms, "RADIUS Delegated-IPv6-Prefix [RFC4818] Salowey, J. and R. Droms, "RADIUS Delegated-IPv6-Prefix
Attribute", RFC 4818, April 2007. Attribute", RFC 4818, April 2007.
[RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", BCP 26, RFC 5226, IANA Considerations Section in RFCs", BCP 26, RFC 5226,
May 2008. May 2008.
[RFC6519] Maglione, R. and A. Durand, "RADIUS Extensions for Dual- [RFC6519] Maglione, R. and A. Durand, "RADIUS Extensions for Dual-
Stack Lite", RFC 6519, February 2012. Stack Lite", RFC 6519, February 2012.
[RFC6911] Dec, W., Sarikaya, B., Zorn, G., Miles, D., and B.
Lourdelet, "RADIUS Attributes for IPv6 Access Networks",
RFC 6911, April 2013.
11.2. Informative References 11.2. Informative References
[RFC3162] Aboba, B., Zorn, G., and D. Mitton, "RADIUS and IPv6", [RFC3162] Aboba, B., Zorn, G., and D. Mitton, "RADIUS and IPv6",
RFC 3162, August 2001. RFC 3162, August 2001.
[RFC3633] Troan, O. and R. Droms, "IPv6 Prefix Options for Dynamic [RFC3633] Troan, O. and R. Droms, "IPv6 Prefix Options for Dynamic
Host Configuration Protocol (DHCP) version 6", RFC 3633, Host Configuration Protocol (DHCP) version 6", RFC 3633,
December 2003. December 2003.
[RFC3646] Droms, R., "DNS Configuration options for Dynamic Host [RFC3646] Droms, R., "DNS Configuration options for Dynamic Host
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