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Versions: (draft-muhanna-netlmm-grekey-option) 00 01 02 03 04 05 06 07 08 09 RFC 5845

Network Working Group                                         A. Muhanna
Internet-Draft                                                 M. Khalil
Intended status: Standards Track                                  Nortel
Expires: February 26, 2009                                 S. Gundavelli
                                                                K. Leung
                                                           Cisco Systems
                                                         August 25, 2008


                  GRE Key Option for Proxy Mobile IPv6
                 draft-ietf-netlmm-grekey-option-00.txt

Status of this Memo

   By submitting this Internet-Draft, each author represents that any
   applicable patent or other IPR claims of which he or she is aware
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   This Internet-Draft will expire on February 26, 2009.

Copyright Notice

   Copyright (C) The IETF Trust (2008).

Abstract

   The Proxy Mobile IPv6 base specification and Proxy Mobile IPv6
   support for IPv4 allow the mobile node's IPv4 and IPv6 traffic
   between the local mobility anchor and the mobile access gateway to be
   tunneled using IPv6 or IPv4 encapsulation headers.  These
   encapsulation modes do not offer the tunnel end-points the required



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   semantics to expose a service identifier that can be used to identify
   traffic for a certain classification, such as for supporting mobile
   nodes that are using overlapping private IPv4 addressing.  The
   extension defined in this document allow the mobile access gateway
   and the local mobility anchor to negotiate GRE encapsulation mode and
   exchange the GRE keys for marking the flows, so tunnel peers can
   process individual flows differently.


Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  3
   2.  Conventions & Terminology  . . . . . . . . . . . . . . . . . .  3
     2.1.  Conventions  . . . . . . . . . . . . . . . . . . . . . . .  3
     2.2.  Terminology  . . . . . . . . . . . . . . . . . . . . . . .  3
   3.  GRE Encapsulation and Key Exchange . . . . . . . . . . . . . .  4
     3.1.  GRE Encapsulation Overview . . . . . . . . . . . . . . . .  4
     3.2.  GRE Encapsulation Support  . . . . . . . . . . . . . . . .  6
     3.3.  GRE Key Exchange Mechanism . . . . . . . . . . . . . . . .  6
       3.3.1.  Initial GRE Key Exchange . . . . . . . . . . . . . . .  6
       3.3.2.  GRE Key Exchange During Binding Re-registration  . . .  6
   4.  Mobile Access Gateway Considerations . . . . . . . . . . . . .  7
     4.1.  Extensions to the Conceptual Data Structure  . . . . . . .  7
     4.2.  Operational Summary  . . . . . . . . . . . . . . . . . . .  8
   5.  Local Mobility Anchor Considerations . . . . . . . . . . . . .  9
     5.1.  Extensions to the Binding Cache Entry  . . . . . . . . . .  9
     5.2.  Operational Summary  . . . . . . . . . . . . . . . . . . . 10
   6.  Message Formats  . . . . . . . . . . . . . . . . . . . . . . . 11
     6.1.  GRE Key Option . . . . . . . . . . . . . . . . . . . . . . 11
     6.2.  Status Codes . . . . . . . . . . . . . . . . . . . . . . . 12
   7.  IANA Considerations  . . . . . . . . . . . . . . . . . . . . . 12
   8.  Security Considerations  . . . . . . . . . . . . . . . . . . . 12
   9.  Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 13
   10. Normative References . . . . . . . . . . . . . . . . . . . . . 13
   Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 14
   Intellectual Property and Copyright Statements . . . . . . . . . . 15















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1.  Introduction

   The base Proxy Mobile IPv6 specification [RFC5213] and Proxy Mobile
   IPv6 support for IPv4 [ID-PMIP6-IPv4] allow the use of IPv6 and IPv4
   encapsulation modes [RFC2473] , [RFC2003] for the tunneled traffic
   between the local mobility anchor and the mobile access gateway.
   There are scenarios where these encapsulation modes are not
   sufficient to uniquely identify the destination of packets of a
   specific flow.  Thus, there is a need for an encapsulation mode with
   richer semantics.  The Generic Routing Encapsulation [RFC2784] and
   the Key extension as defined in [RFC2890], has the required semantics
   to allow such distinction for use in Proxy Mobile IPv6.

   This document defines a new Mobility Option for allowing the MAG and
   the LMA to negotiate GRE encapsulation mode and exchange the downlink
   and uplink GRE keys that can be used for marking the downlink and
   uplink traffic which belong to a specific mobile node session or a
   specific flow.


2.  Conventions & Terminology

2.1.  Conventions

   The keywords "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].

2.2.  Terminology

   All the general mobility related terminology and abbreviations are to
   be interpreted as defined in Mobile IPv6 specification [RFC3775] and
   Proxy Mobile IPv6 specification [RFC5213].  The following terms are
   used in this document.

   Downlink Traffic

      The traffic in the tunnel between the local mobility anchor and
      the mobile access gateway, heading towards the mobile access
      gateway and tunneled at the local mobility anchor.  This traffic
      is also called forward direction traffic.

   Uplink Traffic

      The traffic in the tunnel between the mobile access gateway and
      the local mobility anchor, heading towards the local mobility
      anchor and tunneled at the mobile access gateway.  This traffic is
      also called reverse direction traffic.



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   Downlink GRE Key

      The GRE key is assigned by the mobile access gateway and used by
      the local mobility anchor to mark the downlink traffic which
      belongs to a specific mobile node session or flow as described in
      this document.

   Uplink GRE Key

      The GRE key is assigned by the local mobility anchor and used by
      the mobile access gateway to mark the uplink traffic which belongs
      to a specific mobile node session or flow as described in this
      document.


3.  GRE Encapsulation and Key Exchange

3.1.  GRE Encapsulation Overview

   Using the extension defined in this specification, the mobile access
   gateway and the local mobility anchor can negotiate GRE encapsulation
   mode and exchange the GRE keys for marking the downlink and uplink
   traffic.

   Once the GRE keys have been exchanged between the mobile access
   gateway and the local mobility anchor, the mobile access gateway will
   use the uplink GRE key that is assigned by the local mobility anchor
   in the GRE encapsulation header of the uplink payload packet.
   Similarly, the local mobility anchor will use the downlink GRE key as
   negotiated with the mobile access gateway in the GRE encapsulation
   header of the downlink payload packet.

   The following illustration explains the use of GRE encapsulation mode
   and the GRE keys for supporting the usecase where overlapping IPv4
   private address [RFC1918] allocation is in use.
















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                                                          +------------+
                                                          | Operator-A |
                                                          |            |
                                                          | 10.x.0.0/16|
                                                          +------------+
                                                                   /
        +------+                                      +------+    /
        |      |      ==========================      |      |   /
 MN-1---|      |    /                            \    |      |  / Key-1
        |  M   |   / ---Flows with GRE Key-1 ---- \   |  L   | / Traffic
 MN-2---|  A   |--|                                |--|  M   |-
        |  G   |   \ ---Flows with GRE Key-2 ---- /   |  A   | \ Key-2
 MN-3---|      |    \                            /    |      |  \Traffic
        |      |      ==========================      |      |   \
 MN-4---|      |       Proxy Mobile IPv6 Tunnel       |      |    \
        +------+                                      +------+     \
                                                                    \
                   Operator-C: Access Network             +------------+
                                                          | Operator-B |
                                                          |            |
                                                          | 10.x.0.0/16|
                                                          +------------+



             Figure 1: Overlapping IPv4 Private Address Space



   Figure 1 illustrates a local mobility anchor providing mobility
   service to mobile nodes that are from different operators and are
   assigned IPv4 addresses from overlapping private address space.  In
   this scenario, the mobile access gateway and the local mobility
   anchor must be able distinguish the flows belonging to a given
   operator from the flows belonging to some other operator.

   The mobile nodes, MN-1 and MN-2 are visiting from Operator-A, and
   mobile nodes, MN-3 and MN-4 are visiting from Operator-B.  The mobile
   access gateway and the local mobility anchor exchange a specific pair
   of downlink and uplink GRE keys and save them as part of the mobile
   node binding to be used for identifying the flows belonging to each
   mobile node.

   The LMA and the MAG will be able to distinguish each mobile node
   flow(s) based on the GRE key present in the GRE header of the
   tunneled packet, and route them accordingly.





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3.2.  GRE Encapsulation Support

   To request GRE encapsulation support without exchanging the GRE keys,
   the mobile access gateway MUST include the GRE Key Option in the
   Proxy Binding Update message sent to the local mobility anchor.  The
   mobile access gateway MUST set the length field of the GRE Key option
   to 2 octets.

   If the local mobility anchor supports GRE encapsulation and after
   successfully processes the Proxy Binding Update, the LMA sends a
   Proxy Binding Acknowledgement and MUST include the GRE Key option
   with the length field set to 2 octets.

   However, If the local mobility anchor does not support GRE
   encapsulation, the LMA MUST reject the Proxy Binding Update by
   sending a Proxy Binding Acknowledgement message with the status field
   is set to <IANA-TBA1> as defined in Section 6.2.

3.3.  GRE Key Exchange Mechanism

   The following subsections describe how the mobile access gateway and
   the local mobility anchor exchange downlink and uplink GRE keys using
   proxy mobile IPv6 registration procedure.

3.3.1.  Initial GRE Key Exchange

   When the mobile access gateway determines, based on, e.g., private
   IPv4 address support [RFC1918], the MAG local policy, or the MAG-LMA
   peer agreement, that GRE encapsulation is needed and GRE keys is
   required, the mobile access gateway MUST include the GRE Key Option
   in the initial Proxy Binding Update message sent to the local
   mobility anchor.  The mobile access gateway MUST include the downlink
   GRE key in the GRE Key Identifier field of the GRE Key option.

   After successfully processes the initial PBU and accepting the
   downlink GRE key, the LMA MUST include the GRE Key option with the
   uplink GRE key in the GRE Key Identifier field when sending a
   successful PBA to the MAG.

3.3.2.  GRE Key Exchange During Binding Re-registration

   If the MAG has successfully negotiated and exchanged the initial GRE
   keys with the LMA for a specific binding, the MAG SHOULD NOT include
   the GRE Key option with the downlink GRE key in the Proxy Binding
   Update which is used for requesting a Binding Lifetime Extension.

   However, during inter-MAG handoff and if the new mobile access
   gateway determines, based on, e.g., private IPv4 address support, the



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   MAG local policy, the MAG-LMA peer agreement, or an indication during
   the handoff process, that GRE encapsulation and GRE key exchange is
   required, the new MAG MUST include the GRE key option with the
   downlink GRE key in the Proxy Binding Update which is used for
   requesting an after handoff Binding Lifetime extension.  In this
   case, the downlink GRE key may be identical to the downlink GRE key
   that the previous MAG has exchanged with the LMA for the the same
   binding.

   If the LMA successfully processes an after handoff Binding Lifetime
   extension PBU message which contains a GRE key option with a downlink
   GRE key included, the LMA MUST return the same uplink GRE key that
   was exchanged with the previous MAG and is saved in the respected
   BCE.

   If the LMA receives an after handoff Binding Lifetime extension PBU
   message without the GRE key option for a BCE that is using GRE keys
   and GRE encapsulation, the LMA MUST reject the Proxy Binding Update
   by sending a Proxy Binding Acknowledgement message with the status
   field is set to <IANA-TBA2> as defined in Section 6.2.

   If the LMA receives a no handoff Binding Lifetime extension PBU
   message with the GRE key option and the downlink GRE key included
   from the same MAG that is currently hosting the respected binding
   current pCoA, the LMA MUST NOT reject the PBU because of the GRE key
   option being included in a binding reregistration PBU message.  In
   this case, the LMA processes the PBU normally and if the included
   downlink GRE key is different than the one saved in the respected
   BCE, the LMA MUST update the BCE with the new downlink GRE key.


4.  Mobile Access Gateway Considerations

4.1.  Extensions to the Conceptual Data Structure

   Every mobile access gateway maintains a Binding Update List entry for
   each currently attached mobile node, as explained in Section 6.1 of
   the Proxy Mobile IPv6 specification [RFC5213].  To support this
   specification, the conceptual Binding Update List entry data
   structure must be extended with the following three new additional
   fields.

   o  A flag indicating whether GRE encapsulation is enabled for the
      mobile node's traffic flows.

   o  The Downlink GRE Key used in the GRE encapsulation header of the
      tunneled packet from the local mobility anchor to the mobile
      access gateway that is destined to the mobile node.  This GRE Key



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      is generated by the MAG and communicated to the LMA in the GRE Key
      option in the PBU message.

   o  The Uplink GRE Key used in the GRE encapsulation header of the
      tunneled packet from the mobile access gateway to the local
      mobility anchor that is originating from the mobile node.  This
      GRE Key is obtained from the GRE Key Identifier field of the GRE
      Key option present in the received PBA message sent by the LMA as
      specified in this document.

4.2.  Operational Summary

   o  If the MAG determines that GRE encapsulation and GRE key is
      required, the MAG MUST include the GRE Key option with the
      downlink GRE key in the GRE Key Identifier field in the Proxy
      Binding Update message that is sent by the mobile access gateway
      to the local mobility anchor.

   o  After receiving a successful Proxy Binding Acknowledgment message
      with the GRE Key Option which includes the uplink GRE key, the
      mobile access gateway MUST update the related three fields in the
      mobile node Binding Update List entry described in Section 4.1.
      Additionally, the MAG MUST use the assigned uplink GRE Key for
      tunneling all the traffic originating from the mobile node before
      forwarding the tunneled traffic to the LMA.

   o  For a given mobile node, if the local mobility anchor rejects the
      Proxy Binding Update by sending a Proxy Binding Acknowledgement
      with the status code <IANA-TBA1> (GRE Encapsulation NOT
      supported), the mobile access gateway MUST NOT include the GRE Key
      Option in the subsequent Proxy Binding Update messages that are
      sent to that LMA.

   o  If the mobile access gateway sent a Proxy Binding Update message
      without the GRE Key Option, but the received Proxy Binding
      Acknowledgement has the Status Code <IANA-TBA2>, indicating that
      the GRE encapsulation and GRE key is required, the mobile access
      gateway SHOULD resend the Proxy Binding Update message with the
      GRE Key Option.  If the MAG does not support GRE encapsulation and
      GRE Key Option, the MAG MAY log the event and possibly raise an
      alarm to indicate a possible misconfiguration.

   o  If the mobile access gateway sent a Proxy Binding Update message
      with the GRE Key Option and the downlink GRE key included and
      received a successful PBA message without the GRE key option, the
      mobile access gateway MUST consider that GRE encapsulation and GRE
      keys is not required for this specific binding.  The MAG follows
      the Proxy Mobile IPv6 specification [RFC5213] for the handling of



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      uplink and downlink traffic for this mobile node binding.

   o  If the MAG sent a re-registration PBU message without the GRE Key
      Option, but received a successful PBA which includes the GRE Key
      option with the uplink GRE key, the MAG MUST compare the received
      uplink GRE key with the one saved in the respected Binding Update
      List entry and update it if the received uplink GRE key is
      different.

   o  If the MAG has successfully negotiated and exchanged the initial
      GRE keys with the LMA for a specific binding, the MAG SHOULD NOT
      include the GRE Key option in the de-registration Proxy Binding
      Update.

   o  On receiving a packet from the tunnel with the GRE encapsulation
      header, the mobile access gateway MUST use the GRE Key to
      determine the necessary special processing for the data packet,
      e.g., lookup the mobile node's layer-2 address, determine any
      special processing or treatment for the data packet flow, then
      remove the encapsulation header before forwarding the packet.


5.  Local Mobility Anchor Considerations

5.1.  Extensions to the Binding Cache Entry

   When the local mobility anchor and the mobile access gateway
   successfully negotiates GRE encapsulation and exchange downlink and
   uplink GRE keys, the local mobility anchor MUST maintain the downlink
   and uplink GRE keys as part of the mobile node BCE.  This requires
   that the BCE described in section 5.1 of the Proxy Mobile IPv6 base
   specification [RFC5213] to be extended.  To support this
   specification, the BCE must be extended with the following three
   additional fields.

   o  A flag indicating whether GRE encapsulation is enabled for the
      mobile node's traffic flows.

   o  The Downlink GRE Key, assigned by the MAG and used in the GRE
      encapsulation header of the tunneled packet from the local
      mobility anchor to the mobile access gateway.

   o  The Uplink GRE Key, assigned by the LMA and used in the GRE
      encapsulation header of the tunneled packet from the mobile access
      gateway to the local mobility anchor.






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5.2.  Operational Summary

   o  Upon receiving a Proxy Binding Update message with the GRE Key
      Option and if the local mobility anchor does not support GRE
      encapsulation mode, the LMA MUST send a Proxy Binding
      Acknowledgement message to the MAG with a status code <IANA-TBA1>
      as defined in Section 6.2.

   o  After successfully processes a Proxy Binding Update message with
      the GRE Key Option which includes a downlink GRE key in the GRE
      Key Identifier field for Initial GRE Key exchange as in
      Section 3.3.1, the local mobility anchor MUST include the GRE Key
      option with the uplink GRE key in the GRE Key Identifier field
      when responding with a successful PBA message.

   o  If the GRE tunneling is negotiated and the downlink and uplink GRE
      keys have been exchanged between the mobile access gateway and the
      local mobility anchor for a specific binding, the local mobility
      anchor MUST use the negotiated downlink GRE key in the GRE header
      of every packet that is destined to the mobile node of this
      specific binding over the GRE tunnel to the mobile access gateway.

   o  If the received Proxy Binding Update message does not contain the
      GRE Key Option, and if the local mobility anchor determines that
      GRE encapsulation and GRE key is required, e.g., overlapping IPv4
      private addressing is in use, LMA local policy or LMA-MAG peer
      policy, the local mobility anchor MUST reject the request and send
      the Proxy Binding Acknowledgement message to the mobile access
      gateway with the status code <IANA-TBA2> as defined in
      Section 6.2, indicating that GRE encapsulation and GRE key is
      required.

   o  If after receiving Proxy Binding Update message with the GRE Key
      Option and successfully processes the PBU, the local mobility
      anchor determines that GRE encapsulation and key exchange is not
      required for this specific binding, e.g., private IPv4 addressing
      is not in use, the LMA MUST send a Proxy Binding Acknowledgement
      message to the MAG with the status code success without including
      the GRE Key option.

   o  If the local mobility anchor successfully processes a
      deregistration PBU message which contains a GRE Encapsulation
      option with a downlink GRE key included, the LMA follows the same
      deregistration process as per the base Proxy Mobile IPv6
      specification [RFC5213] to clean the binding cache entry and all
      associated resources including the downlink and uplink GRE keys.





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   o  On receiving a packet from the tunnel with the GRE encapsulation
      header, the local mobility anchor MUST use the GRE Key present in
      the GRE extension header to determine the necessary special
      processing for the data packet, e.g., lookup the mobile node's
      home gateway address, determine any special processing or
      treatment for the data packet flow, then remove the encapsulation
      header before forwarding the packet.


6.  Message Formats

   This section defines an extension to the Mobile IPv6 [RFC3775]
   protocol messages for supporting the GRE tunneling and GRE Key
   exchange for Proxy Mobile IPv6.

6.1.  GRE Key Option

   A new mobility option, the GRE Key Option, is defined for use in the
   Proxy Binding Update and Proxy Binding Acknowledgment messages
   exchanged between the mobile access gateway and the local mobility
   anchor.  This option can be used for negotiating GRE encapsulation
   and exchanging the downlink and uplink GRE keys to be used by the
   peers on all GRE encapsulated packets for the specified mobile node
   binding or flow.

   The alignment requirement for this option is 4n.


       0                   1                   2                   3
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |      Type     |   Length      |           Reserved            |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                      GRE Key Identifier                       |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


                         Figure 2: GRE Key Option

   Type

      <IANA>

   Length

      8-bit unsigned integer indicating the length in octets of the
      option, excluding the type and length fields.  If the Length field
      is set to 2, it indicates that the GRE key is not being carried in



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      the option.  If the length field is set to a value of 6, it means
      that either the downlink or the uplink GRE key is carried.

   Reserved

      These fields are unused.  They MUST be initialized to zero by the
      sender and MUST be ignored by the receiver.

   GRE Key Identifier

      32-bit field containing the Downlink or the Uplink GRE Key. This
      field is present in the GRE Key mobility option only if the GRE
      keys are being exchanged using the PBU and PBA messages.


6.2.  Status Codes

   The following status code values are defined for use in the Binding
   Acknowledgment message when using Proxy Mobile IPv6.

   TBA1: GRE Encapsulation not required.

   TBA2: GRE Encapsulation and GRE Key option required.


7.  IANA Considerations

   This document defines a new Mobility Option, the GRE Key Option,
   described in Section 6.1.  This option is carried in the Mobility
   Header.  The type value for this option needs to be assigned from the
   same numbering space as allocated for the other mobility options
   defined in the Mobile IPv6 specification [RFC3775].

   This document also defines two new Binding Acknowledgement status
   codes TBA1 and TBA2 as described in Section 6.2.  This document
   requests that these two codes be allocated from the "Status Codes"
   registry of the Mobility IPv6 Parameters located at
   http://www.iana.org/assignments/mobility-parameters and that the
   numeric value of these codes be greater than 128.


8.  Security Considerations

   The GRE Key Option, defined in this document, that can be carried in
   Proxy Binding Update and Proxy Binding Acknowledgement messages,
   reveals the group affiliation of a mobile node identified by its NAI
   or an IP address.  It may help an attacker in targeting flows
   belonging to a specific group.  This vulnerability can be prevented,



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   by enabling confidentiality protection on the Proxy Binding Update
   and Acknowledgement messages where the presence of the NAI and GRE
   Key Options establish a mobile node's relation to a specific group.
   This vulnerability can also be avoided by enabling confidentiality
   protection on all the tunneled data packets between the mobile access
   gateway and the local mobility anchor, for hiding all the markings.


9.  Acknowledgements

   The authors would like to thank Alessio Casati, Barney Barnowski,
   Mark Grayson and Parviz Yegani for their input on the need for this
   option.  The authors would like to thank Charlie Perkins, Curtis
   Provost, Irfan Ali, Jouni Korhonen, Julien Langanier, Kuntal
   Chowdhury, Suresh Krishnan, and Vijay Devarapalli for their review
   and comments.


10.  Normative References

   [ID-PMIP6-IPv4]
              Wakikawa, R. and S. Gundavelli, "IPv4 Support for Proxy
              Mobile IPv6", draft-ietf-netlmm-pmip6-ipv4-support-03
              (work in progress), May 2008.

   [RFC1918]  Rekhter, Y., Moskowitz, R., Karrenberg, D., Groot, G., and
              E. Lear, "Address Allocation for Private Internets",
              BCP 5, RFC 1918, February 1996.

   [RFC2003]  Perkins, C., "IP Encapsulation within IP", RFC 2003,
              October 1996.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC2473]  Conta, A. and S. Deering, "Generic Packet Tunneling in
              IPv6 Specification", RFC 2473, December 1998.

   [RFC2784]  Farinacci, D., Li, T., Hanks, S., Meyer, D., and P.
              Traina, "Generic Routing Encapsulation (GRE)", RFC 2784,
              March 2000.

   [RFC2890]  Dommety, G., "Key and Sequence Number Extensions to GRE",
              RFC 2890, September 2000.

   [RFC3775]  Johnson, D., Perkins, C., and J. Arkko, "Mobility Support
              in IPv6", RFC 3775, June 2004.




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   [RFC5213]  Gundavelli, S., Leung, K., Devarapalli, V., Chowdhury, K.,
              and B. Patil, "Proxy Mobile IPv6", RFC 5213, August 2008.



Authors' Addresses

   Ahmad Muhanna
   Nortel
   2221 Lakeside Blvd.
   Richardson, TX  75082
   USA

   Email: amuhanna@nortel.com


   Mohamed Khalil
   Nortel
   2221 Lakeside Blvd.
   Richardson, TX  75082
   USA

   Email: mkhalil@nortel.com


   Sri Gundavelli
   Cisco Systems
   170 West Tasman Drive
   San Jose, CA  95134
   USA

   Email: sgundave@cisco.com


   Kent Leung
   Cisco Systems
   170 West Tasman Drive
   San Jose, CA  95134
   USA

   Email: kleung@cisco.com










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Internet-Draft       GRE Key Option for Proxy MIPv6          August 2008


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