RFC 5778 PROPOSED STANDARD MOBILITY · AAA · DIAMETER
Diameter MIPv6 HA: Diameter Mobile IPv6: Support for Home Agent to Diameter Server Interaction
How a Mobile IPv6 home agent asks a Diameter server to authenticate, authorize and account for a mobile node.
RFC EDITOR
Korhonen, J., Ed., Tschofenig, H., Bournelle, J., Giaretta, G., and M. Nakhjiri, "Diameter Mobile IPv6: Support for Home Agent to Diameter Server Interaction", RFC 5778, DOI 10.17487/RFC5778, February 2010, <https://www.rfc-editor.org/info/rfc5778>.
BIBTEX
@misc{rfc5778,
series = {Request for Comments},
number = 5778,
howpublished = {RFC 5778},
publisher = {RFC Editor},
doi = {10.17487/RFC5778},
url = {https://www.rfc-editor.org/info/rfc5778},
author = {J. Korhonen and H. Tschofenig and J. Bournelle and G. Giaretta and M. Nakhjiri},
title = {{Diameter Mobile IPv6: Support for Home Agent to Diameter Server Interaction}},
pagetotal = 34,
year = 2010,
month = feb,
} RFC text
Contents
Internet Engineering Task Force (IETF) J. Korhonen, Ed.
Request for Comments: 5778 H. Tschofenig
Category: Standards Track Nokia Siemens Networks
ISSN: 2070-1721 J. Bournelle
Orange Labs
G. Giaretta
Qualcomm
M. Nakhjiri
Motorola
February 2010
Diameter Mobile IPv6:
Support for Home Agent to Diameter Server Interaction
Abstract
Mobile IPv6 deployments may want to bootstrap their operations
dynamically based on an interaction between the home agent and the
Diameter server of the Mobile Service Provider. This document
specifies the interaction between a Mobile IP home agent and a
Diameter server.
This document defines the home agent to the Diameter server
communication when the mobile node authenticates using the Internet
Key Exchange v2 protocol with the Extensible Authentication Protocol
or using the Mobile IPv6 Authentication Protocol. In addition to
authentication and authorization, the configuration of Mobile IPv6-
specific parameters and accounting is specified in this document.
Status of This Memo
This is an Internet Standards Track document.
This document is a product of the Internet Engineering Task Force
(IETF). It represents the consensus of the IETF community. It has
received public review and has been approved for publication by the
Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 5741.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc5778.
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.
Table of Contents
1. Introduction ....................................................4
2. Terminology .....................................................6
3. Application Identifiers .........................................6
4. Protocol Description ............................................7
4.1. Support for Mobile IPv6 with IKEv2 and EAP .................7
4.2. Support for the Mobile IPv6 Authentication Protocol .......10
4.3. Mobile IPv6 Session Management ............................11
4.3.1. Session-Termination-Request ........................11
4.3.2. Session-Termination-Answer .........................11
4.3.3. Abort-Session-Request ..............................12
4.3.4. Abort-Session-Answer ...............................12
4.4. Accounting for Mobile IPv6 Services .......................12
4.4.1. Accounting-Request .................................13
4.4.2. Accounting-Answer ..................................13
5. Command Codes ..................................................13
5.1. Command Code for Mobile IPv6 with IKEv2 and EAP ...........13
5.1.1. Diameter-EAP-Request ...............................13
5.1.2. Diameter-EAP-Answer ................................14
5.2. Command Codes for Mobile IPv6 Authentication
Protocol Support ..........................................15
5.2.1. MIP6-Request .......................................16
5.2.2. MIP6-Answer ........................................17
6. AVPs ...........................................................18
6.1. User-Name AVP .............................................21
6.2. Service-Selection AVP .....................................21
6.3. MIP-MN-AAA-SPI AVP ........................................21
6.4. MIP-MN-HA-SPI AVP .........................................22
6.5. MIP-Mobile-Node-Address AVP ...............................22
6.6. MIP6-Agent-Info AVP .......................................22
6.7. MIP-Careof-Address AVP ....................................23
6.8. MIP-Authenticator AVP .....................................23
6.9. MIP-MAC-Mobility-Data AVP .................................23
6.10. MIP-Session-Key AVP ......................................23
6.11. MIP-MSA-Lifetime AVP .....................................23
6.12. MIP-MN-HA-MSA AVP ........................................24
6.13. MIP-Algorithm-Type AVP ...................................24
6.14. MIP-Replay-Mode AVP ......................................24
6.15. MIP6-Feature-Vector AVP ..................................25
6.16. MIP-Timestamp AVP ........................................25
6.17. QoS-Capability AVP .......................................25
6.18. QoS-Resources AVP ........................................25
6.19. Chargeable-User-Identity AVP .............................25
6.20. MIP6-Auth-Mode AVP .......................................25
6.21. Accounting AVPs ..........................................26
7. Result-Code AVP Values .........................................27
7.1. Success ...................................................27
7.2. Permanent Failures ........................................27
8. AVP Occurrence Tables ..........................................27
8.1. DER, DEA, MIR, and MIA AVP/Command-Code Table .............28
8.2. Coupled Accounting Model AVP Table ........................28
9. IANA Considerations ............................................29
9.1. Command Codes .............................................29
9.2. AVP Codes .................................................29
9.3. Result-Code AVP Values ....................................30
9.4. Application Identifier ....................................30
9.5. Namespaces ................................................30
10. Security Considerations .......................................31
11. Acknowledgements ..............................................31
12. References ....................................................32
12.1. Normative References .....................................32
12.2. Informative References ...................................33
1. Introduction
Performing the Mobile IPv6 protocol [RFC3775] requires the mobile
node (MN) to own a home address and to have an assigned home agent
(HA) to the MN. The MN needs to register with the HA in order to
enable its reachability and mobility, when away from its home link.
The registration process itself may require an establishment of IPsec
security associations (SAs) and cryptographic material between the MN
and the HA. Alternatively, the registration process may be secured
using a mobility message authentication option, which enables IPv6
mobility in an MN without having to establish an IPsec SA with its
HA. Providing the collection of home address, HA address, and keying
material is generally referred to as the Mobile IPv6 bootstrapping
problem [RFC4640]. The purpose of this specification is to provide
Diameter support for the interaction between the HA and the
Authentication, Authorization, and Accounting (AAA) server. This
specification satisfies the requirements defined in [RFC5637] for the
bootstrapping problem in the split scenario [RFC5026] and also
specifies Diameter support for the Authentication Protocol for Mobile
IPv6 [RFC4285]. The Diameter support defined in this specification
also applies to Dual Stack Mobile IPv6 [RFC5555].
From a Mobility Service Provider (MSP) perspective, it is important
to verify that the MN is authenticated and authorized to utilize
Mobile IPv6 service, and is accounted for those. Only when the MN is
authenticated and authorized does the MSP allow the bootstrapping of
Mobile IPv6 parameters. Thus, prior to processing the Mobile IPv6
registrations, the HA participates in the authentication of the MN to
verify the MN's identity. The HA also participates in the Mobile
IPv6 authorization process involving the Diameter infrastructure.
The HA, due to its role in traffic forwarding, may also perform
accounting for the Mobile IPv6 service provided to the MN.
This document enables the following functionality:
Authentication: The MN's identity needs to be verified. As a
Diameter client supporting the new Diameter Mobile IPv6
application, the HA may need to support more than one
authentication type depending on the environment. Although the
authentication is performed by the AAA server, there is an impact
for the HA as different sets of command codes are needed for the
respective authentication procedures.
Authorization: The HA must verify that the user is authorized to the
Mobile IPv6 service using the assistance of the MSP Diameter
servers. This is accomplished through the use of new Diameter
applications specifically designed for performing Mobile IPv6
authorization decisions. This document defines required AAA
procedures and requires the HA to support them and to participate
in this authorization signaling.
Accounting: For accounting purposes and capacity planning, it is
required that the HA provides accounting reports to the Diameter
infrastructure and thus supports the related Diameter accounting
procedures.
Session Management: The management of the mobility services may
require the Diameter server or the HA to terminate the Mobile IPv6
service before the binding expires. This document defines
procedures for the AAA-based session management.
Figure 1 depicts the reference architecture for this document.
+--------+
|Diameter|
|Server |
+--------+
^
Back-End | Diameter Mobile IPv6
Protocol | HA<->AAA Server
Support | Interaction
| (this document)
v
+---------+ +---------------+
| Mobile | Front-End Protocol |Home Agent / |
| Node |<-------------------->|Diameter Client|
+---------+ IKEv2 or RFC 4285 +---------------+
Figure 1: Architecture Overview
Mobile IPv6 signaling between the MN and the HA can be protected
using two different mechanisms, namely, using IPsec or the
Authentication Protocol for Mobile IPv6 [RFC4285]. For these two
approaches, several different authentication and key exchange
solutions are available. When IPsec is used to protect Mobile IPv6
signaling messages, Internet Key Exchange v2 (IKEv2) is used
[RFC4877] for the setup of the IPsec SAs. IKEv2 supports EAP-based
(Extensible Authentication Protocol) initiator authentication,
certificates, and pre-shared secrets. Alternatively, the
Authentication Protocol for Mobile IPv6 uses a mechanism that is very
similar to the one used for protecting Mobile IPv4 signaling
messages.
The ability to use different credentials and methods to authenticate
the MN has an impact on the AAA interactions between the HA (acting
as a Diameter client) and the Diameter server. This specification is
only limited to the following MN authentication methods:
o IKEv2 usage with EAP
o Mobile IPv6 Authentication Protocol
New authentication mechanisms may be added later by separate
specifications.
For accounting of Mobile IPv6 services provided to the MN, this
specification uses the Diameter base protocol accounting defined in
[RFC3588].
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].
The Mobile IPv6 bootstrapping terminology is taken from [RFC4640].
Additional terminology is defined below:
Authentication, Authorization, and Accounting (AAA):
AAA protocol based on Diameter [RFC3588] with required EAP support
[RFC4072].
Home AAA (AAAH):
An authentication, authorization, and accounting server located in
the user's home network, i.e., in the home realm.
3. Application Identifiers
This specification defines two new Diameter applications and their
respective Application Identifiers:
Diameter Mobile IPv6 IKE (MIP6I) 7
Diameter Mobile IPv6 Auth (MIP6A) 8
The MIP6I Application Identifier is used when the MN is authenticated
and authorized using IKEv2. The MIP6A Application Identifier is used
when the MN is authenticated and authorized using the Mobile IPv6
Authentication Protocol.
Mobile IPv6-related accounting information generated by the HA uses
either the MIP6I or the MIP6A Application Identifier in the case of
the coupled accounting model. The Diameter Base Accounting
Application Identifier (value of 3) is used in the case of the split
accounting model. Refer to Section 4.4 for more information
regarding the accounting models.
4. Protocol Description
4.1. Support for Mobile IPv6 with IKEv2 and EAP
The use of IKEv2 with EAP between the MN and the HA allows the AAA to
authenticate the MN. When EAP is used with IKEv2, the Diameter EAP
application logic and procedures, as defined in [RFC4072], are re-
used. EAP methods that do not establish a shared key SHOULD NOT be
used, as they are subject to a number of man-in-the-middle attacks as
stated in Section 2.16 and Section 5 of [RFC4306]. Attribute-value
pairs (AVPs) specific to Mobile IPv6 bootstrapping are added to the
EAP application commands.
Figure 2 shows the message flow involved during the authentication
phase when EAP is used. The communication between the mobile node
and the home agent uses the conventions defined in [RFC4306].
Similarly, the communication between the home agent and the Diameter
server uses the conventions defined in [RFC4072].
Mobile Home Diameter
Node Agent Server
| | |
| HDR, SAi1, KEi, Ni (1) | |
|-------------------------------->| |
| | |
| HDR, SAr1, KEr, Nr, [CERTREQ](2)| |
|<--------------------------------| |
| | |
| HDR, SK{IDi,[CERTREQ,] [IDr,] | |
| [CP(CFG_REQUEST),] | |
| SAi2, TSi, TSr} (3) | DER (EAP-Response) (4) + |
|-------------------------------->| MIP6 Bootstrapping AVPs |
| |------------------------->|
| | |
| | DEA (EAP-Request) (5) |
| HDR, SK{IDr, [CERT,] AUTH, EAP} |<-------------------------|
|<------------------------------- | |
| | |
| HDR, SK{EAP} | |
|-------------------------------->| DER (EAP-Response) |
| |------------------------->|
| | |
| | DEA (EAP-Request) |
| HDR, SK{EAP-Request} |<-------------------------|
|<--------------------------------| |
| | |
| HDR, SK{EAP-Response} | |
|-------------------------------->| DER (EAP-Response) |
| |------------------------->|
: ... : ... :
| | |
| | DEA (EAP-Success) + |
| | MIP6 Bootstrapping AVPs |
| HDR, SK{EAP-Success} |<-------------------------|
|<--------------------------------| |
| | |
| HDR, SK{AUTH} | |
|-------------------------------->| |
| | |
| HDR, SK{AUTH, [CP(CFG_REPLY,] | |
| SAr2, TSi, TSr} | |
|<--------------------------------| |
| | |
Figure 2: Mobile IPv6 Bootstrapping Using IKEv2 and EAP
The MN and the HA start the interaction with an IKE_SA_INIT exchange.
In this phase, cryptographic algorithms are negotiated, and nonces
and Diffie-Hellman parameters are exchanged. Message (3) starts the
IKE_AUTH phase. This second phase authenticates the previous
messages, exchanges identities and certificates, and establishes the
first CHILD_SA. It is used to mutually authenticate the MN (acting
as an IKEv2 initiator) and the HA (acting as an IKEv2 responder).
The identity of the user/MN is provided in the IDi field. The MN
indicates its willingness to be authenticated via EAP by omitting the
AUTH field in message (3) (see Section 2.16 of [RFC4306]).
As part of the authentication process, the MN MAY request a home
address or a home prefix or suggest one (see [RFC4877]), using a
CFG_REQUEST payload in the message (3).
The HA extracts the IDi field from the message (3) and sends a
Diameter-EAP-Request (DER) message (4) towards the authenticating
Diameter server. The EAP-Payload AVP contains a EAP-Response/
Identity with the identity extracted from the IDi field.
This message is routed to the MN's Diameter server/EAP server. The
Diameter server selects the EAP method and replies with the Diameter-
EAP-Answer (DEA) message. Depending on the type of EAP method
chosen, a number of DER and DEA messages carry the method-specific
exchanges between the MN and the Diameter server/EAP server.
At the end of the EAP authentication phase, the Diameter server
indicates the result of the authentication in the Result-Code AVP and
provides the corresponding EAP packet (EAP Success or EAP Failure).
The last IKEv2 message sent by the HA contains the home address or
the home prefix. In the latter case, a CREATE_CHILD_SA exchange is
necessary to set up IPsec SAs for Mobile IPv6 signaling.
In some deployment scenarios, the HA may also act as an IKEv2
responder for a conventional IPsec VPN access. The challenge in this
case is that the IKEv2 responder may not know if IKEv2 is used for
Mobile IPv6 service or for IPsec VPN access service. A network
operator needs to be aware of this limitation. One solution already
supported by IKEv2 is to use different responder identities when
operating as a conventional IPsec VPN gateway or as an HA. The MN
can then indicate the preferred responder type using the appropriate
IDr payload in the IKE_AUTH message.
Eventually, when the HA receives a Binding Update (BU), the HA
authenticates and authorizes the MN. It is RECOMMENDED that the HA
sends an accounting request message every time it receives a BU.
4.2. Support for the Mobile IPv6 Authentication Protocol
Figure 3 shows the message sequence between the MN, the HA, and the
Diameter server during the registration when Mobile IPv6
Authentication Protocol is used. A BU and a Binding Acknowledgement
(BA) messages are used in the binding registration process.
Receiving a BU at the HA initiates a MIP6-Request to be sent to the
Diameter server. The Diameter server in turn responds with a MIP6-
Answer. The HA may assign a home address to the MN and provide it to
the Diameter server in the MIP-Mobile-Node-Address AVP.
According to [RFC4285], the MN uses the Mobile Node Identifier
Option, specifically the MN-NAI mobility option (as defined in
[RFC4283]) to identify itself. The HA MUST copy the MN-NAI mobility
option value to the User-Name AVP in the subsequent request messages.
The procedure described in this specification for the Mobile IPv6
Authentication Protocol is only needed for the initially received BU
for which the HA does not have an existing security association.
When the HA receives subsequent BUs, they are processed locally in
the HA. It is RECOMMENDED that the HA sends an accounting request
message every time it receives a Binding Update. However, the HA MAY
re-authorize the MN with the Diameter server at any time depending on
the deployment and the local policy.
This specification assumes that in the case where Mobile IPv6
Authentication Protocol is used, the MN-AAA option is included in the
BU as defined in [RFC4285] and the Diameter server computes required
session keys after having successfully authenticated the MN. The
computation of the session keys is out of scope of this
specification. Other possible ways of using the Mobile IPv6
Authentication Protocol are also out of scope of this specification
and would require a new specification to describe the detailed
behavior of the HA-AAAH interface and corresponding session key
derivation.
Mobile Home Diameter
Node Agent Server
| | |
| | MIP6-Request + MIP6 |
| Binding Update | Bootstrapping AVPs |
|------------------------------------>|-------------------->|
| (Mobile Node Identifier Option, | |
| Mobility Message Replay Protection | |
| Option, Authentication Option) | |
| | |
| | MIP6-Answer + MIP6 |
| Binding Acknowledgement | Bootstrapping AVPs |
|<------------------------------------|<--------------------|
| (Mobile Node Identifier Option | |
| Mobility Message Replay Protection | |
| Option, Authentication Option) | |
Figure 3: Mobile IPv6 Bootstrapping Using the Mobile IPv6
Authentication Protocol
4.3. Mobile IPv6 Session Management
The Diameter server may maintain state or may be stateless. This is
indicated in the Auth-Session-State AVP (or its absence). The HA
MUST support the Authorization Session State Machine defined in
[RFC3588].
This specification makes an assumption that each SA created between
the MN and the HA as a result of a successful IKEv2 negotiation or a
Mobile IPv6 Authentication Protocol exchange corresponds to one
Diameter session. In the IKEv2 case, we specifically mean the
created IKE SA.
4.3.1. Session-Termination-Request
The Session-Termination-Request (STR) message [RFC3588] is sent by
the HA to inform the Diameter server that an authorized session is
being terminated. This means that the HA MUST terminate the
corresponding Mobile IPv6 binding and also terminate the
corresponding SA.
4.3.2. Session-Termination-Answer
The Session-Termination-Answer (STA) message [RFC3588] is sent by the
Diameter server to acknowledge the notification that the session has
been terminated.
4.3.3. Abort-Session-Request
The Abort-Session-Request (ASR) message [RFC3588] is sent by the
Diameter server to the HA to terminate the authorized session. This
fulfills one of the requirement described in [RFC5637]. When the HA
receives the ASR message, it MUST terminate the corresponding SA.
Subsequently, the HA MUST take further actions to terminate the
corresponding Mobile IPv6 binding.
4.3.4. Abort-Session-Answer
The Abort-Session-Answer (ASA) message [RFC3588] is sent by the home
agent in response to an ASR message.
4.4. Accounting for Mobile IPv6 Services
The HA MUST be able act as a Diameter client collecting accounting
records needed for service control and charging. The HA MUST support
the accounting procedures (specifically the command codes mentioned
below) and the Accounting Session State Machine as defined in
[RFC3588]. The command codes, exchanged between the HA and Diameter
server for accounting purposes, are provided in the following
subsections.
The Diameter application design guideline [DIME-APP] defines two
separate models for accounting:
Split accounting model:
According to this model, the accounting messages use the Diameter
Base Accounting Application Identifier (value of 3). Since
accounting is treated as an independent application, accounting
commands may be routed separately from the rest of application
messages and thus the accounting messages generally end up in a
central accounting server. Since the Diameter Mobile IPv6
application does not define its own unique accounting commands,
this is the preferred choice, since it permits use of centralized
accounting for several applications.
Coupled accounting model:
In this model, the accounting messages will use either the MIP6I
or the MIP6A Application Identifiers. This means that accounting
messages will be routed like any other Mobile IPv6 application
messages. This requires the Diameter server in charge of Mobile
IPv6 application to handle the accounting records (e.g., sends
them to a proper accounting server).
As mentioned above, the preferred choice is to use the split
accounting model and thus to choose Diameter Base Accounting
Application Identifier (value of 3) for accounting messages.
4.4.1. Accounting-Request
The Accounting-Request command [RFC3588] is sent by the HA to the
Diameter server to exchange accounting information regarding the MN
with the Diameter server.
4.4.2. Accounting-Answer
The Accounting-Answer command [RFC3588] is sent by the Diameter
server to the HA to acknowledge an Accounting-Request.
5. Command Codes
5.1. Command Code for Mobile IPv6 with IKEv2 and EAP
For the use of Mobile IPv6 with IKEv2 and EAP, this document reuses
the Diameter EAP application [RFC4072] commands: Diameter-EAP-Request
(DER) and Diameter-EAP-Answer (DEA). This specification extends the
existing DER and DEA command ABNFs with a number of AVPs to support
Mobile IPv6 split scenario bootstrapping. Other than new additional
AVPs and the corresponding additions to the command ABNFs, the
Diameter EAP application command ABNFs remain unchanged. The ABNF
language is defined in [RFC3588].
Command-Name Abbrev. Code Reference Application
---------------------------------------------------------------------
Diameter-EAP-Request DER 268 RFC 4072 Diameter Mobile IPv6 IKE
Diameter-EAP-Answer DEA 268 RFC 4072 Diameter Mobile IPv6 IKE
Figure 4: Command Codes
5.1.1. Diameter-EAP-Request
The Diameter-EAP-Request (DER) message, indicated by the Command-Code
field set to 268 and the 'R' bit set in the Command Flags field, is
sent by the HA to the Diameter server to initiate a Mobile IPv6
service authentication and authorization procedure. The
Application-ID field of the Diameter Header MUST be set to the
Diameter Mobile IPv6 IKE Application ID (value of 7). The grouped
AVP has the following modified ABNF (as defined in [RFC3588]):
<Diameter-EAP-Request> ::= < Diameter Header: 268, REQ, PXY >
< Session-Id >
{ Auth-Application-Id }
{ Origin-Host }
{ Origin-Realm }
{ Destination-Realm }
{ Auth-Request-Type }
[ Destination-Host ]
[ NAS-Identifier ]
[ NAS-IP-Address ]
[ NAS-IPv6-Address ]
[ NAS-Port-Type ]
[ User-Name ]
...
{ EAP-Payload }
...
[ MIP6-Feature-Vector ]
[ MIP6-Agent-Info ]
*2[ MIP-Mobile-Node-Address ]
[ Chargeable-User-Identity ]
[ Service-Selection ]
[ QoS-Capability ]
* [ QoS-Resources ]
...
* [ AVP ]
Mobile IPv6 bootstrapping AVPs are only included in the first DER
message send by the HA. The subsequent DER messages required by the
EAP method do not need to include any Mobile IPv6 bootstrapping AVPs.
The MN is both authenticated and authorized for the mobility service
during the EAP authentication. Thus, the Auth-Request-Type AVP MUST
be set to the value AUTHORIZE_AUTHENTICATE.
5.1.2. Diameter-EAP-Answer
The Diameter-EAP-Answer (DEA) message, indicated by the Command-Code
field set to 268 and 'R' bit cleared in the Command Flags field, is
sent in response to the Diameter-EAP-Request (DER) message. The
Application-Id field in the Diameter message header MUST be set to
the Diameter Mobile IPv6 IKE Application-Id (value of 7). If the
Mobile IPv6 authentication procedure was successful, then the
response MAY include any set of bootstrapping AVPs.
<Diameter-EAP-Answer> ::= < Diameter Header: 268, PXY >
< Session-Id >
{ Auth-Application-Id }
{ Auth-Request-Type }
{ Result-Code }
{ Origin-Host }
{ Origin-Realm }
[ User-Name ]
[ EAP-Payload ]
[ EAP-Reissued-Payload ]
[ EAP-Master-Session-Key ]
[ EAP-Key-Name ]
[ Multi-Round-Time ]
...
*2[ MIP-Mobile-Node-Address ]
[ MIP6-Feature-Vector ]
[ MIP6-Agent-Info ]
[ Service-Selection ]
* [ QoS-Resources ]
[ Chargeable-User-Identity ]
...
* [ AVP ]
If the EAP-based authentication and the authorization for the
mobility service succeeds, then the Mobile IPv6 bootstrapping AVPs
are included in the last DEA message that also carries the EAP-
Success EAP payload. The other DEA messages required by the used
EAP-method do not include any Mobile IPv6 bootstrapping AVPs.
5.2. Command Codes for Mobile IPv6 Authentication Protocol Support
This section defines the commands that are used for support with the
Mobile IPv6 Authentication Protocol.
There are multiple ways of deploying and utilizing the Mobile IPv6
Authentication Protocol, especially regarding the associated AAA
interactions. In order to support multiple deployment models, this
specification defines the MIP6-Auth-Mode AVP that in the request
message tells the mode that the HA supports. This specification
defines a method that requires the use of the MN-AAA option with the
Mobile IPv6 Authentication Protocol.
Command-Name Abbrev. Code Reference Application
---------------------------------------------------------------------
MIP6-Request MIR 325 5.3.1 Diameter Mobile IPv6 Auth
MIP6-Answer MIA 325 5.3.2 Diameter Mobile IPv6 Auth
Command Codes
5.2.1. MIP6-Request
The MIP6-Request (MIR), indicated by the Command-Code field set to
325 and the 'R' bit set in the Command Flags field, is sent by the
HA, acting as a Diameter client, in order to request the
authentication and authorization of an MN.
Although the HA provides the Diameter server with replay protection-
related information, the HA is responsible for the replay protection.
The message format is shown below.
<MIP6-Request> ::= < Diameter Header: 325, REQ, PXY >
< Session-ID >
{ Auth-Application-Id }
{ User-Name }
{ Destination-Realm }
{ Origin-Host }
{ Origin-Realm }
{ Auth-Request-Type }
[ Destination-Host ]
[ Origin-State-Id ]
[ NAS-Identifier ]
[ NAS-IP-Address ]
[ NAS-IPv6-Address ]
[ NAS-Port-Type ]
[ Called-Station-Id ]
[ Calling-Station-Id ]
[ MIP6-Feature-Vector ]
{ MIP6-Auth-Mode }
[ MIP-MN-AAA-SPI ]
[ MIP-MN-HA-SPI ]
1*2{ MIP-Mobile-Node-Address }
{ MIP6-Agent-Info }
{ MIP-Careof-Address }
[ MIP-Authenticator ]
[ MIP-MAC-Mobility-Data ]
[ MIP-Timestamp ]
[ QoS-Capability ]
* [ QoS-Resources ]
[ Chargeable-User-Identity ]
[ Service-Selection ]
[ Authorization-Lifetime ]
[ Auth-Session-State ]
* [ Proxy-Info ]
* [ Route-Record ]
* [ AVP ]
If the MN is both authenticated and authorized for the mobility
service, then the Auth-Request-Type AVP is set to the value
AUTHORIZE_AUTHENTICATE. This is the case when the MIP6-Auth-Mode is
set to the value MIP6_AUTH_MN_AAA.
5.2.2. MIP6-Answer
The MIP6-Answer (MIA) message, indicated by the Command-Code field
set to 325 and the 'R' bit cleared in the Command Flags field, is
sent by the Diameter server in response to the MIP6-Request message.
The User-Name AVP MAY be included in the MIA if it is present in the
MIR. The Result-Code AVP MAY contain one of the values defined in
Section 7, in addition to the values defined in [RFC3588].
An MIA message with the Result-Code AVP set to DIAMETER_SUCCESS MUST
include the MIP-Mobile-Node-Address AVP.
The message format is shown below.
<MIP6-Answer> ::= < Diameter Header: 325, PXY >
< Session-Id >
{ Auth-Application-Id }
{ Result-Code }
{ Origin-Host }
{ Origin-Realm }
{ Auth-Request-Type }
[ User-Name ]
[ Authorization-Lifetime ]
[ Auth-Session-State ]
[ Error-Message ]
[ Error-Reporting-Host ]
[ Re-Auth-Request-Type ]
[ MIP6-Feature-Vector ]
[ MIP-Agent-Info ]
*2[ MIP-Mobile-Node-Address ]
[ MIP-MN-HA-MSA ]
* [ QoS-Resources ]
[ Chargeable-User-Identity ]
[ Service-Selection ]
[ Origin-State-Id ]
* [ Proxy-Info ]
* [ Redirect-Host ]
[ Redirect-Host-Usage ]
[ Redirect-Max-Cache-Time ]
* [ Failed-AVP ]
* [ AVP ]
6. AVPs
To provide support for [RFC4285] and for [RFC4877], the AVPs in the
following subsections are needed. [RFC3588], [RFC4004], and
[RFC4005] defined AVPs are reused whenever possible without changing
the existing semantics of those AVPs.
+--------------------+
| AVP Flag Rules |
+----+---+------+----+----+
AVP Defined | | |SHOULD|MUST|MAY |
Attribute Name Code in Value Type |MUST|MAY| NOT | NOT|Encr|
+------------------------------------------+----+---+------+----+----+
|MIP6-Feature- 124 RFC 5447 Unsigned64 | M | P | | V | Y |
| Vector | | | | | |
+------------------------------------------+----+---+------+----+----+
|MIP-Mobile- | M | P | | V | Y |
| Node-Address 333 RFC 4004 Address | | | | | |
+------------------------------------------+----+---+------+----+----+
|MIP6-Agent-Info 486 RFC 5447 Grouped | M | P | | V | Y |
+------------------------------------------+----+---+------+----+----+
|User-Name 1 RFC 3588 UTF8String | M | P | | V | Y |
+------------------------------------------+----+---+------+----+----+
|Service- 493 6.2 UTF8String | M | P | | V | Y |
| Selection | | | | | |
+------------------------------------------+----+---+------+----+----+
|QoS-Capability 578 Note 1 Grouped | M | P | | V | Y |
+------------------------------------------+----+---+------+----+----+
|QoS-Resources 508 Note 1 Grouped | M | P | | V | Y |
+------------------------------------------+----+---+------+----+----+
|MIP-MN-HA-MSA 492 6.12 Grouped | M | P | | V | Y |
+------------------------------------------+----+---+------+----+----+
|Chargeable-User- OctetString| M | P | | V | Y |
| Identity 89 6.19 | | | | | |
+------------------------------------------+----+---+------+----+----+
AVPs for Mobile IPv6 IKE Application
Note 1: The QoS-Capability and the QoS-Resource AVPs are defined in
Sections 4.1 and 4.3 of [RFC5777].
+--------------------+
| AVP Flag Rules |
+----+---+------+----+----+
AVP Section | | |SHOULD|MUST|MAY |
Attribute Name Code Defined Value Type |MUST|MAY| NOT | NOT|Encr|
+------------------------------------------+----+---+------+----+----+
|MIP6-Feature- 124 RFC 5447 Unsigned64 | M | P | | V | Y |
| Vector | | | | | |
+------------------------------------------+----+---+------+----+----+
|User-Name 1 RFC 3588 UTF8String | M | P | | V | Y |
+------------------------------------------+----+---+------+----+----+
|Service- 493 6.2 UTF8String | M | P | | V | Y |
| Selection | | | | | |
+------------------------------------------+----+---+------+----+----+
|MIP-MN-AAA-SPI 341 RFC 4004 Unsigned32 | M | P | | V | Y |
+------------------------------------------+----+---+------+----+----+
|MIP-MN-HA-SPI 491 6.4 Unsigned32 | M | P | | V | Y |
+------------------------------------------+----+---+------+----+----+
|MIP-Mobile- 333 RFC 4004 Address | M | P | | V | Y |
| Node-Address | | | | | |
+------------------------------------------+----+---+------+----+----+
|MIP6-Agent-Info 486 RFC 5447 Grouped | M | P | | V | Y |
+------------------------------------------+----+---+------+----+----+
|MIP-Careof- 487 6.7 Address | M | P | | V | Y |
| Address | | | | | |
+------------------------------------------+----+---+------+----+----+
|MIP- 488 6.8 OctetString| M | P | | V | Y |
| Authenticator | | | | | |
+------------------------------------------+----+---+------+----+----+
|MIP-MAC- 489 6.9 OctetString| M | P | | V | Y |
| Mobility-Data | | | | | |
+------------------------------------------+----+---+------+----+----+
|MIP-Session-Key 343 6.10 OctetString| M | P | | V | Y |
+------------------------------------------+----+---+------+----+----+
|MIP-MSA- 367 RFC 4004 Unsigned32 | M | P | | V | Y |
| Lifetime | | | | | |
+------------------------------------------+----+---+------+----+----+
|MIP-MN-HA-MSA 492 6.12 Grouped | M | P | | V | Y |
+------------------------------------------+----+---+------+----+----+
|MIP-Algorithm- 345 6.13 Enumerated | M | P | | V | Y |
| Type | | | | | |
+------------------------------------------+----+---+------+----+----+
|MIP-Replay-Mode 346 6.14 Enumerated | M | P | | V | Y |
+------------------------------------------+----+---+------+----+----+
|MIP-Timestamp 490 6.16 OctetString| M | P | | V | Y |
+------------------------------------------+----+---+------+----+----+
|QoS-Capability 578 Note 1 Grouped | M | P | | V | Y |
+------------------------------------------+----+---+------+----+----+
|QoS-Resources 508 Note 1 Grouped | M | P | | V | Y |
+------------------------------------------+----+---+------+----+----+
|Chargeable-User- OctetString| M | P | | V | Y |
| Identity 89 6.19 | | | | | |
+------------------------------------------+----+---+------+----+----+
|MIP6-Auth-Mode 494 6.20 Enumerated | M | P | | V | Y |
+------------------------------------------+----+---+------+----+----+
|Rest of the AVPs RFC 3588 | M | P | | V | Y |
|in the MIR & MIA RFC 4005 | | | | | |
|excluding *[AVP] | | | | | |
+------------------------------------------+----+---+------+----+----+
AVPs for the Mobile IPv6 Auth Application
Note 1: The QoS-Capability and the QoS-Resource AVPs are defined in
Sections 4.1 and 4.3 of [RFC5777].
6.1. User-Name AVP
The User-Name AVP (AVP Code 1) is of type UTF8String and contains a
Network Access Identifier (NAI) extracted from the MN-NAI mobility
option included in the received BU message. Alternatively, the NAI
can be extracted from the IKEv2 IDi payload included in the IKE_AUTH
message sent by the IKE initiator.
6.2. Service-Selection AVP
The Service-Selection AVP (AVP Code 493) is of type UTF8String and
contains the name of the service or the external network with which
the mobility service should be associated. In the scope of this
specification, the value can be extracted from the IKEv2 IDr payload,
if available in the IKE_AUTH message sent by the IKE initiator.
Alternatively, if the Mobile IPv6 Authentication Protocol is used,
then the Service-Selection AVP contains the string extracted from the
Service Selection Mobility Option [RFC5149], if available in the
received BU. Future specifications may define additional ways to
populate the Service-Selection AVP with the required information.
The AVP is also available to be used in messages sent from the
Diameter server to the Diameter client. For example, if the request
message did not contain the Service-Selection AVP but the MN was
assigned with a default service, the Diameter server MAY return the
name of the assigned default service to the HA.
If the Service-Selection AVP is present in both the request and the
reply messages, it SHOULD contain the same service name. If the
services differ, the HA MAY treat that as authorization failure.
6.3. MIP-MN-AAA-SPI AVP
The MIP-MN-AAA-SPI AVP (AVP Code 341) is of type Unsigned32 and
contains a Security Parameter Index (SPI) code extracted from the
Mobility Message Authentication Option included in the received BU
message. This AVP is reused from [RFC4004].
When the MIP6-Auth-Mode AVP is set to value MIP6_AUTH_MN_AAA, this
AVP MUST be present in the MIR message.
6.4. MIP-MN-HA-SPI AVP
The MIP-MN-HA-SPI AVP (AVP Code 491) is of type Unsigned32 and
contains an SPI value that can be used with other parameters for
identifying the security association required for the validation of
the Mobile IPv6 MN-HA Authentication Option.
When the MIP6-Auth-Mode AVP is set to value MIP6_AUTH_MN_AAA, and the
Diameter server returns a valid MIP-MN-HA-MSA AVP in the MIA message,
this AVP MUST be present inside the MIP-MN-HA-MSA AVP.
6.5. MIP-Mobile-Node-Address AVP
The MIP-Mobile-Node-Address AVP (AVP Code 333) is of type Address and
contains the HA assigned IPv6 or IPv4 home address of the mobile
node.
If the MIP-Mobile-Node-Address AVP contains the unspecified IPv6
address (0::0) or the all-zeroes IPv4 address (0.0.0.0) in a request
message, then the HA expects the Diameter server to assign the home
address in a subsequent answer message. If the Diameter server
assigns only an IPv6 home network prefix to the mobile node, the
lower 64 bits of the MIP-Mobile-Node-Address AVP provided address
MUST be set to zero.
This AVP is reused from [RFC4004].
6.6. MIP6-Agent-Info AVP
The MIP6-Agent-Info AVP (AVP Code 486) is defined in Section 4.2.1 of
[RFC5447] and contains the IPv6 or the IPv4 address information of
the HA. The HA address in a request message is the same as in the
received BU message that triggered the authentication and
authorization procedure towards the Diameter server. One use case
is, e.g., to inform the Diameter server of the dynamically assigned
HA.
If the MIP6-Agent-Info AVP is present in an answer message and the
Result-Code AVP is set to DIAMETER_SUCCESS_RELOCATE_HA, then the
Diameter server is indicating to the HA that it MUST initiate an HA
switch procedure towards the MN (e.g., using the procedure defined in
[RFC5142]). If the Result-Code AVP is set to any other value, then
the HA SHOULD initiate the HA switch procedure towards the MN. The
address information of the assigned HA is defined in the MIP6-Agent-
Info AVP.
6.7. MIP-Careof-Address AVP
The MIP-Careof-Address AVP (AVP Code 487) is of type Address and
contains the IPv6 or the IPv4 care-of address of the mobile node.
The HA extracts this IP address from the received BU message.
6.8. MIP-Authenticator AVP
The MIP-Authenticator AVP (AVP Code 488) is of type OctetString and
contains the Authenticator Data from the received BU message. The HA
extracts this data from the MN-AAA Mobility Message Authentication
Option included in the received BU message.
When the MIP6-Auth-Mode AVP is set to value MIP6_AUTH_MN_AAA, this
AVP MUST be present in the MIR message.
6.9. MIP-MAC-Mobility-Data AVP
The MIP-MAC-Mobility-Data AVP (AVP Code 489) is of type OctetString
and contains the MAC_Mobility_Data calculated by the HA as defined in
[RFC4285] for the MN-AAA Mobility Message Authentication Option.
When the MIP6-Auth-Mode AVP is set to value MIP6_AUTH_MN_AAA, this
AVP MUST be present in the MIR message.
6.10. MIP-Session-Key AVP
The MIP-Session-Key AVP (AVP Code 343) is of type OctetString and
contains the MN-HA shared secret (i.e., the session key) for the
associated Mobile IPv6 MN-HA authentication option. When the
Diameter server computes the session key, it is placed in this AVP.
How the Diameter server computes the session key is not defined in
this specification. The Session key derivation is deployment
specific and needs to be defined in a respective deployment-specific
system specification.
This AVP is reused from [RFC4004].
6.11. MIP-MSA-Lifetime AVP
The MIP-MSA-Lifetime AVP (AVP Code 367) is of type Unsigned32 and
represents the period of time (in seconds) for which the session key
(see Section 6.10) is valid. The associated session key MUST NOT be
used if the lifetime has expired.
This AVP is reused from [RFC4004].
6.12. MIP-MN-HA-MSA AVP
The MIP-MN-HA-MSA AVP (AVP Code 492) is of type Grouped and contains
the session-related information for use with the Mobile IPv6
Authentication Protocol.
MIP-MN-HA-MSA ::= < AVP Header: 492 >
{ MIP-Session-Key }
{ MIP-MSA-Lifetime }
[ MIP-MN-HA-SPI ]
[ MIP-Algorithm-Type ]
[ MIP-Replay-Mode ]
* [ AVP ]
The MIP-MN-HA-SPI sub-AVP within the MIP-MN-HA-MSA grouped AVP
identifies the security association required for the validation of
the Mobile IPv6 MN-HA Authentication Option. The absence of the MIP-
Replay-Mode AVP MUST be treated as no replay protection was selected.
6.13. MIP-Algorithm-Type AVP
The MIP-Algorithm-Type AVP (AVP Code 345) is of type Enumerated and
contains the Algorithm identifier for the associated Mobile IPv6
MN-HA Authentication Option. The Diameter server selects the
algorithm type. Existing algorithm types are defined in [RFC4004]
that also fulfill current RFC 4285 requirements. This AVP is reused
from [RFC4004].
When the MIP6-Auth-Mode AVP is set to value MIP6_AUTH_MN_AAA, and the
Diameter server returns a valid MIP-MN-HA-MSA AVP in the MIA message,
this AVP MUST be present inside the MIP-MN-HA-MSA AVP.
6.14. MIP-Replay-Mode AVP
The MIP-Replay-Mode AVP (AVP Code 346) is of type Enumerated and
contains the replay mode of the HA for authenticating the mobile
node. Out of all possible replay modes defined in [RFC4004], the
following are supported by this specification:
1 None
2 Timestamp
This AVP is reused from [RFC4004].
6.15. MIP6-Feature-Vector AVP
The MIP6-Feature-Vector AVP (AVP Code 124) is defined in [RFC5447].
However, this specification does not define any Mobile IPv6 split
scenario bootstrapping specific capability flag.
6.16. MIP-Timestamp AVP
The MIP-Timestamp AVP (AVP Code 490) is of type OctetString and
contains an 8-octet timestamp value (i.e., 64-bit timestamp) from the
Mobility message replay protection option, defined in [RFC4285]. The
HA extracts this value from the received BU message, if available.
The HA includes this AVP in the MIR message when the MN-AAA Mobility
Message Authentication Option is available in the received BU and the
Diameter server is expected to return the key material required for
the calculation and validation of the Mobile IPv6 MN-HA
Authentication Option (and the MIP6-Auth-Mode AVP is set to value
MIP6_AUTH_MN_AAA).
6.17. QoS-Capability AVP
The QoS-Capability AVP is defined in [RFC5777] and contains a list of
supported Quality of Service profiles.
6.18. QoS-Resources AVP
The QoS-Resources AVP is defined in [RFC5777] and provides QoS and
packet filtering capabilities.
6.19. Chargeable-User-Identity AVP
The Chargeable-User-Identity AVP (AVP Code 89) is of type OctetString
and contains a unique temporary handle of the user. The Chargeable-
User-Identity is defined in [RFC4372].
6.20. MIP6-Auth-Mode AVP
The MIP6-Auth-Mode (AVP Code 494) is of type Enumerated and contains
information of the used Mobile IPv6 Authentication Protocol mode.
This specification defines only one value MIP6_AUTH_MN_AAA and the
corresponding AAA interactions when MN-AAA security association is
used to authenticate the Binding Update as described in [RFC4285].
When the MIP6-Auth_Mode AVP is set to the value of MIP6_AUTH_MN_AAA,
the Auth-Request-Type AVP MUST be set to the value of
AUTHORIZE_AUTHENTICATE.
If the Diameter server does not support the Mobile IPv6
Authentication Protocol usage mode proposed by the HA, then the
Diameter server MUST fail the authentication/authorization and MUST
set the Result-Code AVP to the value of DIAMETER_ERROR_AUTH_MODE.
6.21. Accounting AVPs
Diameter Mobile IPv6 applications, either MIP6I or MIP6A, are used in
the case of the coupled account model. Diameter Mobile IPv4
application [RFC4004] accounting AVPs are reused in this document.
The following AVPs SHOULD be included in the accounting request
message:
o Accounting-Input-Octets: Number of octets in IP packets received
from the mobile node.
o Accounting-Output-Octets: Number of octets in IP packets sent by
the mobile node.
o Accounting-Input-Packets: Number of IP packets received from the
mobile node.
o Accounting-Output-Packets: Number of IP packets sent by the mobile
node.
o Acct-Multi-Session-Id: Used to link together multiple related
accounting sessions, where each session would have a unique
Session-Id, but the same Acct-Multi-Session-Id AVP.
o Acct-Session-Time: Indicates the length of the current session in
seconds.
o MIP6-Feature-Vector: The supported features for this mobility
service session.
o MIP-Mobile-Node-Address: The home address of the mobile node.
o MIP-Agent-Info: The current home agent of the mobile node.
o Chargeable-User-Identity: The unique temporary identity of the
user. This AVP MUST be included if it is available in the home
agent.
o Service-Selection: Currently selected mobility service.
o QoS-Resources: Assigned Quality-of-Service (QoS) resources for the
mobile node.
o QoS-Capability: The QoS capability related to the assigned QoS-
Resources.
o MIP-Careof-Address: The current care-of address of the mobile
node.
7. Result-Code AVP Values
This section defines new Result-Code [RFC3588] values that MUST be
supported by all Diameter implementations that conform to this
specification.
7.1. Success
Errors that fall within the Success category are used to inform a
peer that a request has been successfully completed.
DIAMETER_SUCCESS_RELOCATE_HA (Status Code 2009)
This result code is used by the Diameter server to inform the HA
that the MN MUST be switched to another HA.
7.2. Permanent Failures
Errors that fall within the Permanent Failures category are used to
inform the peer that the request failed and SHOULD NOT be attempted
again.
DIAMETER_ERROR_MIP6_AUTH_MODE (Status Code 5041)
This error code is used by the Diameter server to inform the peer
that the requested Mobile IPv6 Authentication Protocol usage mode
is not supported.
8. AVP Occurrence Tables
The following tables present the AVPs defined in this document and
their occurrences in Diameter messages. Note that AVPs that can only
be present within a Grouped AVP are not represented in this table.
The tables use the following symbols:
0:
The AVP MUST NOT be present in the message.
0+:
Zero or more instances of the AVP MAY be present in the message.
0-1:
Zero or one instance of the AVP MAY be present in the message.
1:
One instance of the AVP MUST be present in the message.
8.1. DER, DEA, MIR, and MIA AVP/Command-Code Table
+-----------------------+
| Command-Code |
|-----+-----+-----+-----+
AVP Name | DER | DEA | MIR | MIA |
-------------------------------|-----+-----+-----+-----+
MIP6-Feature-Vector | 0-1 | 0-1 | 0-1 | 0-1 |
MIP-Mobile-Node-Address | 1-2 | 0-2 | 1-2 | 0-2 |
MIP-MN-AAA-SPI | 0 | 0 | 0-1 | 0 |
MIP-MN-HA-SPI | 0 | 0 | 0-1 | 0 |
MIP6-Agent-Info | 1 | 0-1 | 1 | 0-1 |
MIP-Careof-Address | 0 | 0 | 0-1 | 0 |
MIP-Authenticator | 0 | 0 | 0-1 | 0 |
MIP-MAC-Mobility-Data | 0 | 0 | 0-1 | 0 |
MIP-MSA-Lifetime | 0 | 0 | 0 | 1 |
MIP-MN-HA-MSA | 0 | 0 | 0 | 0-1 |
MIP-Timestamp | 0 | 0 | 0-1 | 0-1 |
User-Name | 0-1 | 0-1 | 1 | 0-1 |
Service-Selection | 0-1 | 0-1 | 0-1 | 0-1 |
QoS-Resources | 0+ | 0+ | 0+ | 0+ |
QoS-Capability | 0-1 | 0 | 0-1 | 0 |
Chargeable-User-Identity | 0-1 | 0-1 | 0-1 | 0-1 |
MIP6-Auth-Mode | 0 | 0 | 1 | 0 |
+-----+-----+-----+-----+
8.2. Coupled Accounting Model AVP Table
The table in this section is used to represent which AVPs defined in
this document are to be present in the Accounting messages, as
defined in [RFC3588].
+-------------+
| Command-Code|
|------+------+
Attribute Name | ACR | ACA |
-------------------------------------|------+------+
Accounting-Input-Octets | 0-1 | 0-1 |
Accounting-Input-Packets | 0-1 | 0-1 |
Accounting-Output-Octets | 0-1 | 0-1 |
Accounting-Output-Packets | 0-1 | 0-1 |
Acct-Multi-Session-Id | 0-1 | 0-1 |
Acct-Session-Time | 0-1 | 0-1 |
MIP6-Feature-Vector | 0-1 | 0-1 |
MIP6-Agent-Info | 0-1 | 0-1 |
MIP-Mobile-Node-Address | 0-2 | 0-2 |
Event-Timestamp | 0-1 | 0 |
MIP-Careof-Address | 0-1 | 0 |
Service-Selection | 0-1 | 0 |
QoS-Capability | 0+ | 0+ |
QoS-Resources | 0+ | 0+ |
Chargeable-User-Identity | 0-1 | 0 |
-------------------------------------|------+------+
9. IANA Considerations
This section contains the namespaces that have either been created in
this specification or had their values assigned to existing
namespaces managed by IANA.
9.1. Command Codes
IANA has allocated a command code value for the following new command
from the Command Code namespace defined in [RFC3588]. See Section 5
for the assignment of the namespace in this specification.
Command Code | Value
-----------------------------------+------
MIP6-Request/Answer (MIR/MIA) | 325
9.2. AVP Codes
IANA has registered the following new AVPs from the AVP Code
namespace defined in [RFC3588].
o MIP-Careof-Address
o MIP-Authenticator
o MIP-MAC-Mobility-Data
o MIP-Timestamp
o MIP-MN-HA-SPI
o MIP-MN-HA-MSA
o Service-Selection
o MIP6-Auth-Mode
The AVPs are defined in Section 6.
9.3. Result-Code AVP Values
IANA has allocated new values to the Result-Code AVP (AVP Code 268)
namespace defined in [RFC3588]. See Section 7 for the assignment of
the namespace in this specification.
Result-Code | Value
----------------------------------------------+------
DIAMETER_SUCCESS_RELOCATE_HA | 2009
DIAMETER_ERROR_MIP6_AUTH_MODE | 5041
9.4. Application Identifier
IANA has allocated two new values "Diameter Mobile IPv6 IKE" and
"Diameter Mobile IPv6 Auth" from the Application Identifier namespace
defined in [RFC3588].
Application Identifier | Value
-----------------------------------+------
Diameter Mobile IPv6 IKE (MIP6I) | 7
Diameter Mobile IPv6 Auth (MIP6A) | 8
9.5. Namespaces
IANA has created a new registry, "MIP6 Authentication Mode Registry",
for use with the enumerated MIP6-Auth-Mode AVP. The registry
initially contains the following value:
Token | Value | Description
---------------------------------------------+----------+------------
MIP6_AUTH_MN_AAA | 1 | RFC 5778
Allocation of new values follow the example policies described in
[RFC5226]. New values for the MIP6-Auth-Mode AVP will be assigned
based on the "Specification Required" policy. The value 0 (zero) is
reserved, and the maximum value is 4294967295 (i.e., 2^32-1).
10. Security Considerations
The security considerations for the Diameter interaction required to
accomplish the split scenario are described in [RFC5026].
Additionally, the security considerations of the Diameter base
protocol [RFC3588], and Diameter EAP application [RFC4072] are
applicable to this document.
The Diameter messages may be transported between the HA and the
Diameter server via one or more AAA brokers or Diameter agents. In
this case, the HA to the Diameter server AAA communication relies on
the security properties of the intermediating AAA inter-connection
networks, AAA brokers, and Diameter agents (such as proxies).
In the case of the Authentication Protocol for Mobile IPv6 [RFC4285],
this specification expects that the Diameter server derives the MN-HA
Security Association and returns the associated session key (i.e.,
the MN-HA shared session key) to the HA. However, this specification
does not define nor do other IETF specifications define how the
Diameter server actually derives required keys. The details of the
key derivation depends on the deployment where this specification is
used and therefore the security properties of the system depend on
how this is done.
11. Acknowledgements
The authors would like to thank Jari Arkko, Tolga Asversen, Pasi
Eronen, Santiago Zapata Hernandez, Anders Kristensen, Avi Lior, John
Loughney, Ahmad Muhanna, Behcet Sarikaya, Basavaraj Patil, Vijay
Devarapalli, Lionel Morand, Domagoj Premec, Semyon Mizikovsky, and
Yoshihiro Ohba for all the useful discussions. Ahmad Muhanna
provided a detailed review of the document in August 2007. Pasi
Eronen provided detailed comments and text proposals during the IESG
review that helped to improved this document greatly.
We would also like to thank our Area Director, Dan Romascanu, for his
support.
Hannes Tschofenig would like to thank the European Commission support
in the co-funding of the ENABLE project, where this work is partly
being developed.
Julien Bournelle would like to thank GET/INT since he began this work
while he was under their employ.
Madjid Nakhjiri would like to thank Huawei USA as most of his
contributions to this document were possible while he was under their
employ.
12. References
12.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC3588] Calhoun, P., Loughney, J., Guttman, E., Zorn, G., and J.
Arkko, "Diameter Base Protocol", RFC 3588,
September 2003.
[RFC3775] Johnson, D., Perkins, C., and J. Arkko, "Mobility Support
in IPv6", RFC 3775, June 2004.
[RFC4004] Calhoun, P., Johansson, T., Perkins, C., Hiller, T., and
P. McCann, "Diameter Mobile IPv4 Application", RFC 4004,
August 2005.
[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.
[RFC4283] Patel, A., Leung, K., Khalil, M., Akhtar, H., and K.
Chowdhury, "Mobile Node Identifier Option for Mobile IPv6
(MIPv6)", RFC 4283, November 2005.
[RFC4285] Patel, A., Leung, K., Khalil, M., Akhtar, H., and K.
Chowdhury, "Authentication Protocol for Mobile IPv6",
RFC 4285, January 2006.
[RFC4306] Kaufman, C., "Internet Key Exchange (IKEv2) Protocol",
RFC 4306, December 2005.
[RFC4372] Adrangi, F., Lior, A., Korhonen, J., and J. Loughney,
"Chargeable User Identity", RFC 4372, January 2006.
[RFC4877] Devarapalli, V. and F. Dupont, "Mobile IPv6 Operation
with IKEv2 and the Revised IPsec Architecture", RFC 4877,
April 2007.
[RFC5026] Giaretta, G., Kempf, J., and V. Devarapalli, "Mobile IPv6
Bootstrapping in Split Scenario", RFC 5026, October 2007.
[RFC5142] Haley, B., Devarapalli, V., Deng, H., and J. Kempf,
"Mobility Header Home Agent Switch Message", RFC 5142,
January 2008.
[RFC5149] Korhonen, J., Nilsson, U., and V. Devarapalli, "Service
Selection for Mobile IPv6", RFC 5149, February 2008.
[RFC5447] Korhonen, J., Bournelle, J., Tschofenig, H., Perkins, C.,
and K. Chowdhury, "Diameter Mobile IPv6: Support for
Network Access Server to Diameter Server Interaction",
RFC 5447, February 2009.
[RFC5777] Korhonen, J., Tschofenig, H., Arumaithurai, M., Jones,
M., Ed., and A. Lior, "Traffic Classification and Quality
of Service (QoS) Attributes for Diameter", RFC 5777,
February 2010.
12.2. Informative References
[DIME-APP] Fajardo, V., Asveren, T., Tschofenig, H., McGregor, G.,
and J. Loughney, "Diameter Applications Design
Guidelines", Work in Progress, July 2009.
[RFC4640] Patel, A. and G. Giaretta, "Problem Statement for
bootstrapping Mobile IPv6 (MIPv6)", RFC 4640,
September 2006.
[RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", BCP 26, RFC 5226,
May 2008.
[RFC5555] Soliman, H., "Mobile IPv6 Support for Dual Stack Hosts
and Routers", RFC 5555, June 2009.
[RFC5637] Giaretta, G., Guardini, I., Demaria, E., Bournelle, J.,
and R. Lopez, "Authentication, Authorization, and
Accounting (AAA) Goals for Mobile IPv6", RFC 5637,
September 2009.
Authors' Addresses
Jouni Korhonen (editor)
Nokia Siemens Networks
Linnoitustie 6
Espoo FIN-02600
Finland
EMail: jouni.nospam@gmail.com
Hannes Tschofenig
Nokia Siemens Networks
Linnoitustie 6
Espoo FIN-02600
Finland
Phone: +358 (50) 4871445
EMail: Hannes.Tschofenig@gmx.net
URI: http://www.tschofenig.priv.at
Julien Bournelle
Orange Labs
38-4O rue du general Leclerc
Issy-Les-Moulineaux 92794
France
EMail: julien.bournelle@orange-ftgroup.com
Gerardo Giaretta
Qualcomm
5775 Morehouse Dr
San Diego, CA 92121
USA
EMail: gerardo.giaretta@gmail.com
Madjid Nakhjiri
Motorola
USA
EMail: madjid.nakhjiri@motorola.com
AI ELI5
On this page
PROBLEMA Mobile IPv6 home agent needs to know that a mobile node is allowed to use the service, and needs its home address and keys, without every deployment inventing its own way to ask the operator's AAA system.
MECHANISMThe home agent acts as a Diameter client. For IKEv2 with EAP it reuses the Diameter EAP commands (DER and DEA), and for the Mobile IPv6 Authentication Protocol it uses two new commands, MIP6-Request and MIP6-Answer, with added AVPs that carry the bootstrapping data.
WHY IT MATTERSIt defines two new Diameter applications, MIP6I (7) and MIP6A (8), plus session management and accounting rules. It is a Proposed Standard, and it leaves the actual session key derivation to each deployment.
§1The Bootstrapping Problem
In Mobile IPv6, a mobile node (MN) owns a home address and has a home agent (HA). The MN registers with the HA so it can still be reached when it is away from its home link. That registration may need IPsec security associations and keying material, or it may be protected by a mobility message authentication option instead. Providing the home address, the HA address and the keys is called the Mobile IPv6 bootstrapping problem.
This RFC supplies the Diameter side of the answer. The mobility service provider wants to be sure the MN is authenticated, authorized and accounted for before any parameters are handed out. So the HA takes part in authentication, authorization and accounting (AAA) through the provider's Diameter infrastructure. The document covers four functions: authentication, authorization, accounting and session management.
It is limited to two MN authentication methods: IKEv2 with EAP, and the Mobile IPv6 Authentication Protocol from RFC 4285. New methods can be added by separate specifications.
A traveling kid wants to keep getting letters at the old house. Before the helper forwards anything, the helper checks with the head office that the kid is allowed to use the service.
§2Architecture and Application Identifiers
Figure 1 of the RFC shows three parties. The MN talks to the HA with a front-end protocol, either IKEv2 or the protocol of RFC 4285. The HA also acts as a Diameter client and talks to the Diameter server (the home AAA server, or AAAH, in the user's home realm) over the back-end protocol that this document defines.
The RFC defines two new Diameter applications:
- MIP6I (Diameter Mobile IPv6 IKE), Application Identifier
7, used when the MN is authenticated and authorized using IKEv2. - MIP6A (Diameter Mobile IPv6 Auth), Application Identifier
8, used when the Mobile IPv6 Authentication Protocol is used.
Accounting is a separate choice. In the coupled model accounting messages carry the MIP6I or MIP6A identifier. In the split model they use the Diameter Base Accounting identifier, value 3.
There are two different forms at the head office, one for people who show a special ID card and one for people who use a secret handshake. Each form has its own number so the clerks know which one it is.
§3Authenticating the Mobile Node
IKEv2 with EAP. The MN and HA start with an IKE_SA_INIT exchange to negotiate algorithms and swap nonces and Diffie-Hellman values. In the first IKE_AUTH message the MN leaves out the AUTH field to show it wants EAP, and it may use a CFG_REQUEST payload to ask for or suggest a home address or home prefix. The HA pulls the identity out of the IDi field and sends a Diameter-EAP-Request (DER) to the Diameter server, with an EAP-Response/Identity inside. The server chooses the EAP method and answers with Diameter-EAP-Answer (DEA) messages. The Diameter EAP logic of RFC 4072 is reused as it is. EAP methods that do not establish a shared key SHOULD NOT be used, because of man-in-the-middle attacks.
Mobile IPv6 Authentication Protocol. Here a Binding Update (BU) arriving at the HA triggers a MIP6-Request to the Diameter server, and the server replies with a MIP6-Answer. The HA copies the value of the MN-NAI mobility option into the User-Name AVP. This exchange is only needed for the first BU, when the HA has no security association yet; later BUs are handled locally, though the HA MAY re-authorize the MN at any time. The RFC assumes the MN-AAA option is present in the BU and that the Diameter server computes the session keys, but how it does that is out of scope.
In both cases it is RECOMMENDED that the HA sends an accounting request every time it receives a BU. If the HA also serves conventional IPsec VPN access, one approach already supported by IKEv2 is to use different responder identities for the two roles.
Either the kid shows an ID card to the helper, who phones the head office, or the kid sends a sealed note that the head office checks. In both cases the helper only lets the mail follow the kid after the head office says yes.
Mobile NodeHome AgentDiameter Server
- IKE_SA_INIT requestHDR, SAi1, KEi, Ni
- IKE_SA_INIT response
- IKE_AUTH, no AUTH fieldCarries IDi and may ask for a home address.
- DER (EAP-Response) + MIP6 AVPs
- DEA (EAP-Request)
- IKE_AUTH with EAP
- DEA (EAP-Success) + MIP6 AVPsSent after more DER and DEA rounds as the EAP method needs.
- SK{EAP-Success}
Mobile NodeHome AgentDiameter Server
- Binding UpdateMobile Node Identifier, replay protection and authentication options.
- MIP6-Request + MIP6 AVPs
- MIP6-Answer + MIP6 AVPs
- Binding Acknowledgement
§4Commands and AVPs
For IKEv2 with EAP the RFC reuses the Diameter EAP commands DER and DEA, both with command code 268, and adds Mobile IPv6 AVPs to their definitions. The DER must set Application-ID to 7 and the Auth-Request-Type AVP to AUTHORIZE_AUTHENTICATE. The Mobile IPv6 bootstrapping AVPs appear only in the first DER and, on success, in the last DEA that carries EAP-Success.
For the Mobile IPv6 Authentication Protocol it defines two new commands: MIP6-Request (MIR) and MIP6-Answer (MIA), both with command code 325. The MIR carries the MIP6-Auth-Mode AVP and, for the MN-AAA mode, the SPI, authenticator and mobility data taken from the BU. A MIA with DIAMETER_SUCCESS MUST include the MIP-Mobile-Node-Address AVP.
Notable AVPs include:
MIP-Mobile-Node-Address(333): the home address. If a request carries0::0or0.0.0.0, the HA expects the server to assign one.MIP6-Agent-Info(486): the HA address. With the result code DIAMETER_SUCCESS_RELOCATE_HA the server tells the HA it MUST start an HA switch.MIP-MN-HA-MSA(492): a grouped AVP holding the session key, its lifetime and related data.MIP6-Auth-Mode(494): the authentication mode; only MIP6_AUTH_MN_AAA is defined.
Two new result codes are added: DIAMETER_SUCCESS_RELOCATE_HA (2009) and DIAMETER_ERROR_MIP6_AUTH_MODE (5041), the latter for a mode the server does not support.
The messages are forms with labeled boxes. Some boxes say who the kid is, some say where the kid is now, and some hold a secret key the helper will use.
| Application | Identifier | Commands | Command code | Used with |
|---|---|---|---|---|
| MIP6I | 7 | DER / DEA | 268 | IKEv2 with EAP |
| MIP6A | 8 | MIR / MIA | 325 | Mobile IPv6 Authentication Protocol |
§5Session Management and Accounting
Each security association between the MN and HA created by a successful IKEv2 negotiation or Mobile IPv6 Authentication Protocol exchange corresponds to one Diameter session. The HA MUST support the Authorization Session State Machine of RFC 3588.
Either side can end the session early. The HA sends a Session-Termination-Request, and then MUST terminate the Mobile IPv6 binding and the SA. The Diameter server can send an Abort-Session-Request, and the HA MUST terminate the SA and then the binding.
The HA MUST also be able to act as a Diameter client that collects accounting records. The split accounting model, using Application Identifier 3, is the preferred choice because it permits centralized accounting for several applications. In the coupled model the accounting AVPs that SHOULD be included cover octet and packet counts in each direction, session time, the home address, the current care-of address and the Chargeable-User-Identity.
If the head office says stop, or the kid says stop, the helper closes the forwarding and tells the other side. The helper also keeps count of how many letters were forwarded, like a meter.
§6IANA Registrations
IANA allocated command code 325 for MIP6-Request/Answer, two Application Identifiers (7 for MIP6I and 8 for MIP6A), and the Result-Code values 2009 and 5041. It also registered new AVPs such as MIP-Careof-Address, MIP-Authenticator, MIP-MAC-Mobility-Data, MIP-Timestamp, MIP-MN-HA-SPI, MIP-MN-HA-MSA, Service-Selection and MIP6-Auth-Mode.
A new registry, the MIP6 Authentication Mode Registry, holds the values for MIP6-Auth-Mode. It starts with MIP6_AUTH_MN_AAA at value 1. New values need the Specification Required policy, and the value 0 is reserved.
The numbers for the new forms were written in the official number book, so nobody else uses the same ones by accident.
§7Security Considerations
The RFC points to the security considerations of RFC 5026, the Diameter base protocol and the Diameter EAP application. Messages may pass through AAA brokers or Diameter agents such as proxies, so HA-to-server communication depends on the security of those intermediaries.
For the Mobile IPv6 Authentication Protocol the Diameter server derives the MN-HA security association and returns the session key to the HA. Neither this RFC nor other IETF specifications define how the server derives it. The overall security of the system therefore depends on how each deployment does that.
The messages may pass through other offices on the way, so you have to trust them. And how the secret key is made is left for each post office to decide, so how safe it is depends on them.
§8References
[RFC3588]RFC 3588Calhoun, P., Loughney, J., Guttman, E., Zorn, G., and J. Arkko, "Diameter Base Protocol", RFC 3588, September 2003.September 2003[RFC3775]RFC 3775Johnson, D., Perkins, C., and J. Arkko, "Mobility Support in IPv6", RFC 3775, June 2004.June 2004[RFC4004]RFC 4004Calhoun, P., Johansson, T., Perkins, C., Hiller, T., and P. McCann, "Diameter Mobile IPv4 Application", RFC 4004, August 2005.August 2005[RFC4072]RFC 4072Eronen, P., Hiller, T., and G. Zorn, "Diameter Extensible Authentication Protocol (EAP) Application", RFC 4072, August 2005.August 2005[RFC4285]RFC 4285Patel, A., Leung, K., Khalil, M., Akhtar, H., and K. Chowdhury, "Authentication Protocol for Mobile IPv6", RFC 4285, January 2006.January 2006[RFC4877]RFC 4877Devarapalli, V. and F. Dupont, "Mobile IPv6 Operation with IKEv2 and the Revised IPsec Architecture", RFC 4877, April 2007.April 2007[RFC5026]RFC 5026Giaretta, G., Kempf, J., and V. Devarapalli, "Mobile IPv6 Bootstrapping in Split Scenario", RFC 5026, October 2007.October 2007[RFC5447]RFC 5447Korhonen, J., Bournelle, J., Tschofenig, H., Perkins, C., and K. Chowdhury, "Diameter Mobile IPv6: Support for Network Access Server to Diameter Server Interaction", RFC 5447, February 2009.February 2009[RFC5777]RFC 5777Korhonen, J., Tschofenig, H., Arumaithurai, M., Jones, M., Ed., and A. Lior, "Traffic Classification and Quality of Service (QoS) Attributes for Diameter", RFC 5777, February 2010.February 2010