[Docs] [txt|pdf] [Tracker] [WG] [Email] [Diff1] [Diff2] [Nits] [IPR]

Versions: (draft-zhou-netext-pd-pmip) 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 RFC 7148

Netext WG                                                        X. Zhou
Internet-Draft                                           ZTE Corporation
Intended status: Standards Track                             J. Korhonen
Expires: August 29, 2013                          Nokia Siemens Networks
                                                             C. Williams
                                                              Consultant
                                                           S. Gundavelli
                                                                   Cisco
                                                           CJ. Bernardos
                                                                    UC3M
                                                       February 25, 2013


                Prefix Delegation for Proxy Mobile IPv6
                      draft-ietf-netext-pd-pmip-06

Abstract

   Proxy Mobile IPv6 enables IP mobility for a host without requiring
   its participation in any mobility signaling, being the network
   responsible for managing IP mobility on behalf of the host.  However,
   Proxy Mobile IPv6 does not support assigning a prefix to a router and
   managing its IP mobility.  This document specifies an extension to
   Proxy Mobile IPv6 protocol for supporting network mobility using
   DHCPv6-based Prefix Delegation.

Status of this Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at http://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on August 29, 2013.

Copyright Notice

   Copyright (c) 2013 IETF Trust and the persons identified as the
   document authors.  All rights reserved.




Zhou, et al.             Expires August 29, 2013                [Page 1]


Internet-Draft    Prefix Delegation Support for PMIPv6     February 2013


   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 . . . . . . . . . . . . . . . . . . . . . . . . .  3
   2.  Convention and Terminology . . . . . . . . . . . . . . . . . .  4
   3.  Message formats  . . . . . . . . . . . . . . . . . . . . . . .  5
     3.1.  Delegated Mobile Network Prefix Option . . . . . . . . . .  5
   4.  DHCPv6 Prefix Delegation Support for Proxy Mobile IPv6 . . . .  7
     4.1.  Assumptions  . . . . . . . . . . . . . . . . . . . . . . .  7
     4.2.  Network Mobility Service . . . . . . . . . . . . . . . . .  8
     4.3.  Binding association with the delegated prefix  . . . . . .  8
       4.3.1.  Delegating Router Co-located with Mobile Access
               Gateway  . . . . . . . . . . . . . . . . . . . . . . .  8
       4.3.2.  Deletion of the Delegated Prefix in Proxy Mobile
               IPv6 . . . . . . . . . . . . . . . . . . . . . . . . . 10
     4.4.  Delegating Router Co-located with the Local Mobility
           Anchor . . . . . . . . . . . . . . . . . . . . . . . . . . 10
       4.4.1.  Mobile Router initiated prefix delegation in PMIPv6  . 11
       4.4.2.  Refreshing the Delegated Prefix in Proxy Mobile
               IPv6 . . . . . . . . . . . . . . . . . . . . . . . . . 13
       4.4.3.  Deletion of the Delegated Prefix in Proxy Mobile
               IPv6 . . . . . . . . . . . . . . . . . . . . . . . . . 13
   5.  Mobile Access Gateway Operation  . . . . . . . . . . . . . . . 14
     5.1.  Extension to Binding Update List Entry Data Structure  . . 14
     5.2.  Forwarding . . . . . . . . . . . . . . . . . . . . . . . . 14
     5.3.  Handover . . . . . . . . . . . . . . . . . . . . . . . . . 14
   6.  Local Mobility Anchor Operation  . . . . . . . . . . . . . . . 16
     6.1.  Extension to Binding Cache Entry Data Structure  . . . . . 16
     6.2.  Forwarding . . . . . . . . . . . . . . . . . . . . . . . . 16
   7.  Security Considerations  . . . . . . . . . . . . . . . . . . . 17
   8.  IANA Considerations  . . . . . . . . . . . . . . . . . . . . . 19
   9.  Acknowledgments  . . . . . . . . . . . . . . . . . . . . . . . 20
   10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 21
     10.1. Normative References . . . . . . . . . . . . . . . . . . . 21
     10.2. Informative References . . . . . . . . . . . . . . . . . . 21
   Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 23





Zhou, et al.             Expires August 29, 2013                [Page 2]


Internet-Draft    Prefix Delegation Support for PMIPv6     February 2013


1.  Introduction

   Proxy Mobile IPv6 [RFC5213] enables network-based mobility management
   support for an IP host without requiring its participation in any IP
   mobility signaling.  The mobility elements in the network allow the
   IP host to obtain an IPv4 address and/or a set of IPv6 prefix and be
   able to obtain IP mobility support for those IP addresses.  However,
   this network-based mobility management support is specific to an IP
   host and currently there is no such network-based mobility management
   support for a mobile router with a cluster of IP hosts behind it.
   This specification defines extensions to Proxy Mobile IPv6 protocol
   for allowing a mobile router to be able to obtain one or more
   delegated IPv4/IPv6 prefixes for its inside networks using DHCP
   Prefix Delegation extensions [RFC3633].  The mobility entities in the
   network will provide network-based mobility management support for
   these delegated prefixes just as how that is supported for Home
   Network prefixes.


































Zhou, et al.             Expires August 29, 2013                [Page 3]


Internet-Draft    Prefix Delegation Support for PMIPv6     February 2013


2.  Convention and 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].

   All the mobility related terms used in this document are to be
   interpreted as defined in Mobile IPv6 (MIPv6) [RFC6275], Proxy Mobile
   IPv6 specifications [RFC5213], [RFC5844], DHCPv6-PD for NEMO
   [RFC6276], DHCPv6-PD [RFC3633] Subnet Allocation Option for DHCPv4
   [RFC6656] and Mobility Related Terminology [RFC3753].  This document
   also provides a context-specific explanation to the following terms
   used in this document.

   Mobile Router (MR)

      Throughout this document, the term mobile router is used to refer
      to an IP router whose mobility is managed by the network while
      being attached to a Proxy Mobile IPv6 domain.  The mobile router
      is not required to participate in any IP mobility related
      signaling for achieving mobility for an IPv4/IPv6 prefix that is
      obtained in that Proxy Mobile IPv6 domain.

   Delegated Mobile Network Prefix (DMNP)

      The DMNP is an IPv4 or an IPv6 prefix delegated to a mobile router
      and advertised in the mobile network.  More than one Delegated
      Mobile Network Prefix could be assigned to a mobile router.  The
      DMNP is topologically anchored on the local mobility anchor.
      While used by the mobile router, the mobile access gateway and
      local mobility anchor provide mobility service to the mobile
      router for the DMNP(s).



















Zhou, et al.             Expires August 29, 2013                [Page 4]


Internet-Draft    Prefix Delegation Support for PMIPv6     February 2013


3.  Message formats

   This section defines extensions to Proxy Mobile IPv6 [RFC5213]
   protocol messages.

3.1.  Delegated Mobile Network Prefix Option

   A new Delegated Mobile Network Prefix option is defined for use with
   the Proxy Binding Update and Proxy Binding Acknowledgment messages
   exchanged between a local mobility anchor and a mobile access
   gateway.  This option is used for exchanging the mobile router's
   IPv4/IPv6 delegated mobile network prefix information.  There can be
   multiple Delegated Mobile Network Prefix options present in the
   message.

   The Delegated Mobile Network Prefix option has an alignment
   requirement of 8n+2.  Its format is as follows:

   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      |K|  Reserved   | Prefix Length |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                 GRE Key Identifier (optional)                 |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                                               |
   +                                                               +
   |                                                               |
   .                                                               .
   +           IPv4 or IPv6 Delegated Mobile Network Prefix        +
   |                                                               |
   +                                                               +
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


   Type

      To be assigned by IANA.

   Length

      8-bit unsigned integer indicating the length of the option in
      octets, excluding the type and length fields.

   Key present (K)





Zhou, et al.             Expires August 29, 2013                [Page 5]


Internet-Draft    Prefix Delegation Support for PMIPv6     February 2013


      If the Key Present bit is set to 1, then it indicates that the GRE
      Key Identifier field includes a valide GRE Key. Otherwise, the
      value of the GRE Key Identifier field MUST be ignored by the
      receiver.

   Reserved

      This field is unused for now.  The value MUST be initialized to 0
      by the sender and MUST be ignored by the receiver.

   Prefix Length

      8-bit unsigned integer indicating the prefix length of the prefix
      contained in the option.

   Generic Routing Encapsulation (GRE) key tag

      A four-byte optional field containing the GRE key tag as specified
      in [RFC2890].  If the Key Present flag is set to 0, this field
      MUST be initialized to 0 by the sender and MUST be ignored by the
      receiver.  This option MAY be used by the LMA to provide
      differentiated service to different clients attached to the same
      mobile router.

      The MAG includes the GRE key in the Proxy Binding Update and the
      LMA uses that key to mark the downlink mobile network traffic from
      the LMA to the MAG.

      The LMA includes the GRE key in the Proxy Binding Acknowledgment
      and the MAG uses that key to mark the uplink mobile network
      traffic from the MAG to the LMA.

   Delegated Mobile Network Prefix

      Contains a mobile router's 4-byte IPv4 or a 16-byte IPv6 Delegated
      Mobile Network Prefix.















Zhou, et al.             Expires August 29, 2013                [Page 6]


Internet-Draft    Prefix Delegation Support for PMIPv6     February 2013


4.  DHCPv6 Prefix Delegation Support for Proxy Mobile IPv6

4.1.  Assumptions

   This specification extends Proxy Mobile IPv6 (PMIPv6) to delegate a
   mobile network IPv4/IPv6 prefix to a mobile router (MR) for
   supporting network mobility.  The specification assumes that a mobile
   router is an IPv4/IPv6 router without any capability for mobility
   management.

   The mobile router after its attachment to the network obtains an IPv6
   address from its home network prefix (HNP) on its egress interface
   facing the MAG.  This is as specified in [RFC5213] and [RFC5844].
   Subsequently, the DHCPv6-PD procedures get activated for obtaining
   the delegated IPv6/IPv4 prefixes for its ingress networks.

   The mobile router using the DHCP Prefix Delegation approaches
   specified in [RFC3633] and [RFC6656] will obtain the delegated IPv4/
   IPv6 prefix from the network.  The mobile router forwards outgoing
   packets from its mobile network to the mobile access gateway (MAG),
   and the MAG delivers the incoming packets to the mobile network
   through the MR.

   The mobile router must have obtained an IPv6 address from its home
   network prefix (HNP) before initiating DHCPv6-PD procedures for
   obtaining delegated IPv4 or IPv6 prefixes for its ingress networks.
   This IPv6 address is on the interface attached to the MN-MAG access
   link as specified in [RFC3633].

   The MR (acting as a RR) SHOULD support Prefix Exclude Option for
   DHCPv6-PD as described in [RFC6603].  It essentially allows the home
   network prefix on the MN-MAG link and the delegated prefix can be
   part of the same aggregated block.  This simplies address pool
   management aspects

   This specification supports the following two configuration modes:

   1.  The delegating router (DR) function, as specified in [RFC3633],
       is co-located with the MAG.  The DHCP requesting router (RR)
       functionality is enabled on the mobile router.

   2.  The delegating router (DR) function, as specified in [RFC3633],
       is co-located with the LMA.  A DHCPv6 Relay Agent (DRA) function,
       as specified in [RFC3633], is co-located on the mobile access
       gateway.  The DHCP requesting router (RR), as specified in
       [RFC3633] functionality is enabled on the mobile router.





Zhou, et al.             Expires August 29, 2013                [Page 7]


Internet-Draft    Prefix Delegation Support for PMIPv6     February 2013


4.2.  Network Mobility Service

   The network mobility service of a mobile router is indicated by the
   policy profile defined in [RFC5213].  During the mobile router's
   initial attachment procedure, the mobile access gateway MUST identify
   the mobile router and SHOULD acquire the policy profile to determine
   whether the network mobility service is offered to the mobile router.
   If the network mobility service needs to be offered to the mobile
   router, the mobile access gateway MUST set the Mobile Router Flag (R)
   when sending the Proxy Binding Update (PBU) message to the local
   mobility anchor.

4.3.  Binding association with the delegated prefix

4.3.1.  Delegating Router Co-located with Mobile Access Gateway

      +-----+            +-----+                    + ----+
      | MR  |            | MAG |                    | LMA |
      |(RR) |            | (DR)|                    |     |
      +-----+            +-----+                    +-----+
   1)    |-- MN Attach -----|                          |
         |                  |<-------- PBU/PBA ------->|
         |                  |                          |
         |                  |o========================o|
   2)    |                  |      PMIPv6 tunnel       |
         |                  |o========================o|
   3)    |-- Solicit ------>|                          |
         | for delegated    |                          |
         |   prefix         |                          |
         |                  |                          |
   4)    |                  |----------PBU------------>|
         |                  |                          |
   5)    |                  |<---------PBA (DMNP)------|
         |                  |                          |
         -                  -<---+                     |
   6)    |<- Advertise -----|    |                     |
         |                  |    |                     |
   7)    |-- Request ------>| Optional                 |
         |                  |    |                     |
         -                  -<---+                     |
   8)    |<-- Reply (DMNP) -|                          |
         |                  |                          |
         |                  |                          |

     Figure 1: Prefix Delegation in PMIPv6 when DR co-located with MAG

   The steps required to complete the delegation of IPv6 prefix(es) to a
   mobile router that is provided with network mobility service are the



Zhou, et al.             Expires August 29, 2013                [Page 8]


Internet-Draft    Prefix Delegation Support for PMIPv6     February 2013


   following (see Figure 1):

   1.  MAG after detecting the mobile node's attachment to the access
       link initiates the signaling with the LMA.

   2.  The PMIPv6 tunnel is set up between the MAG and the LMA as
       described in [RFC5213].  This requires the MAG to send a regular
       PBU to the LMA to register the location of the mobile router and
       set-up the bi-directional tunnel.  The LMA binds the allocated
       home network prefix (HNP) to the Proxy-CoA of the mobile router
       (i.e., the address of the mobile access gateway where the MR is
       attached to).  It is possible that the delegated prefix(es) may
       have been assigned to the MAG by the LMA during this procedure of
       PMIPv6 tunnel establishment.  That is the MAG may include one (or
       more) Delegated Mobile Network Prefix (DMNP) mobility options
       which MUST be set to the unspecified IPv6 address "::" in the PBU
       to request the delegated prefix(es).  The LMA assigns a new set
       of DMNP(s) in PBA message.

   3.  The mobile router, acting as a "Requesting Router" as described
       in [RFC3633], sends a DHCPv6 SOLICIT message including one or
       more IA_PD option(s) to the mobile access gateway (which has a
       "DHCPv6 Server" function) to acquire the delegated prefix(es).

   4.  Upon receiving the DHCPv6 SOLICIT message, the mobile access
       gateway sends a proxy binding update (PBU) message to the local
       mobility anchor, including one (or more) Delegated Mobile Network
       Prefix (DMNP) mobility options.  All the considerations from
       Section 5.3.1 of [RFC5213] MUST be applied on the encapsulated
       Proxy Binding Update message.  If the mobile access gateway does
       not know the delegated prefix(es), then the delegated mobile
       network prefix in the DMNP option(s) MUST be set to the
       unspecified IPv6 address "::", or an IPv4 address of 0.0.0.0 with
       the prefix length of 0.  The local mobility anchor either assigns
       the MR a new set of delegated IPv4/IPv6 prefix(es) or returns the
       existing one(s) that are associated with that mobility session.

   5.  On reception of the proxy binding update, the local mobility
       anchor returns the assigned prefix(es) in the DMNP option(s)
       conveyed in a proxy binding acknowledgment (PBA) message sent to
       the mobile access gateway, unless the prefix(es) included in the
       PBU was the IPv6 unspecified address "::".  The assigned
       prefix(es) MUST be the same one(s) which will be assigned via
       DHCPv6PD in step 6.  The prefix(es) MUST be added to the
       delegated prefix(es) in the local mobility anchor binding cache
       which is extended as described in Section 6.1.  The LMA must set
       up forwarding for the delegated prefixes as reachable through the
       PMIPv6 tunnel.



Zhou, et al.             Expires August 29, 2013                [Page 9]


Internet-Draft    Prefix Delegation Support for PMIPv6     February 2013


   6.  The delegating router function on the MAG sends the delegated
       prefix(es) in one or more IA_PD(s) which were received in the PBA
       message in step 5 to the mobile router inside the DHCPv6
       ADVERTISE message.

   7.  The mobile router sends the DHCPv6 REQUEST message with the IA_PD
       option(s) received from previous message to the DR function on
       the mobile access gateway.

       Note: steps 6 to 7 are not present if DHCPv6 Rapid Commit is
       used.

   8.  The DR function on the mobile access gateway responds to the
       REQUEST from the mobile router with a DHCPv6 REPLY message.  The
       MAG sets up the forwarding for the delegated prefixes.  The
       delegated prefixes are reachable over the MN-MAG interface with
       the MR's link-local address, or home address as the next-hop
       destination.

4.3.2.  Deletion of the Delegated Prefix in Proxy Mobile IPv6

   If the lifetime of the delegated prefix (included in the IA_PD Prefix
   Option carried by the DHCPv6 Reply message) is set to zero, the
   mobile access gateway (which is acting as "Delegating Router") MUST
   send a proxy binding update message to remove the selective binding
   for that delegated mobile network prefix.  If the request is for
   remove the delegeted mobile network prefix only, the proxy binding
   update message with the lifetime value of (0) MUST NOT include either
   IPv6 Home Network Prefix option [RFC5213] or IPv4 Home Address
   Request option [RFC5844].

4.4.  Delegating Router Co-located with the Local Mobility Anchor



















Zhou, et al.             Expires August 29, 2013               [Page 10]


Internet-Draft    Prefix Delegation Support for PMIPv6     February 2013


4.4.1.  Mobile Router initiated prefix delegation in PMIPv6

      +-----+            +-----+                    + ----+
      | MR  |            | MAG |                    | LMA |
      |(RR) |            |(DRA)|                    |(DR) |
      +-----+            +-----+                    +-----+
   1)    |-- MN Attach -----|                          |
         |                  |<------ PBU/PBA --------->|
         |                  |                          |
         |                  |o========================o|
   2)    |                  |      PMIPv6 tunnel       |
         |                  |o========================o|
   3)    |-- Solicit ------>|                          |
         | for delegated    |                          |
   4)    |   prefix         |----------PBU------------>|
         |                  |                          |
   5)    |                  |<---------PBA (DMNP)------|
         |                  |                          |
   6)    |                  |--- Solicit ------------->|
         -                  -                          - <---+
   7)    |                  |<-- Advertise ------------|     |
         |                  |                          |     |
   8)    |<- Advertise -----|                          |     |
         |                  |                          |  Optional
   9)    |-- Request ------>|                          |     |
         |                  |                          |     |
   10)   |                  |--- Request ------------->|     |
         -                  -                          - <---+
   11)   |                  |<-- Reply (DMNP) ---------|
         |                  |                          |
   12)   |<-- Reply (DMNP) -|                          |
         |                  |                          |

     Figure 2: Prefix Delegation in PMIPv6 when DR co-located with LMA

   The steps required to complete the delegation of IPv6 prefix(es) to a
   mobile router that is provided with network mobility service are the
   following (see Figure 2):

   1.   MAG after detecting the mobile node's attachment to the access
        link initiates the signaling with the LMA.

   2.   The PMIPv6 tunnel is set up between the MAG and the LMA as
        described in [RFC5213].  This requires the MAG to send a regular
        PBU to the LMA to register the location of the mobile router and
        set-up the bi-directional tunnel.  The LMA binds the allocated
        home network prefix (HNP) to the Proxy-CoA of the mobile router
        (i.e., the address of the mobile access gateway where the MR is



Zhou, et al.             Expires August 29, 2013               [Page 11]


Internet-Draft    Prefix Delegation Support for PMIPv6     February 2013


        attached to).

   3.   The mobile router, acting as a "Requesting Router" as described
        in [RFC3633], sends a DHCPv6 SOLICIT message including one or
        more IA_PD option(s) to the mobile access gateway (which has a
        "DHCPv6 Relay Agent" function) to acquire the delegated
        prefix(es).

   4.   Upon receiving the DHCPv6 SOLICIT message, the mobile access
        gateway sends a proxy binding update (PBU) message to the local
        mobility anchor, including one (or more) Delegated Mobile
        Network Prefix (DMNP) mobility options.  All the considerations
        from Section 5.3.1 of [RFC5213] MUST be applied on the
        encapsulated Proxy Binding Update message.  If the mobile access
        gateway does not know the delegated prefix(es), then the
        delegated mobile network prefix in the DMNP option(s) MUST be
        set to the unspecified IPv6 address "::", or an IPv4 address of
        0.0.0.0 with the prefix length of 0.  The local mobility anchor
        either assigns the MR a new set of delegated IPv4/IPv6
        prefix(es) or returns the existing one(s) that are associated
        with that mobility session.

   5.   On reception of the proxy binding update, the local mobility
        anchor returns the assigned prefix(es) in the DMNP option(s)
        conveyed in a proxy binding acknowledgment (PBA) message sent to
        the mobile access gateway, unless the prefix(es) included in the
        PBU was the IPv6 unspecified address "::".  The assigned
        prefix(es) MUST be the same one(s) which will be assigned via
        DHCPv6PD in step 6.  The prefix(es) MUST be added to the
        delegated prefix(es) in the local mobility anchor binding cache
        which is extended as described in Section 6.1.  The LMA must set
        up forwarding for the delegated prefixes as reachable through
        the PMIPv6 tunnel.

   6.   The DHCPv6 Relay Agent function on the mobile access gateway
        relays the DHCPv6 SOLICIT message to the delegating router (as
        described in [RFC3633] ).  The delegating router inserts one or
        more IA_PD option(s) including the delegated prefix(es) in the
        reply message.

        Note: steps 6 to 9 are not present if DHCPv6 Rapid Commit is
        used.

   7.   The delegating router sends the delegated prefix(es) in one or
        more IA_PD(s) to the mobile access gateway (acting as "DHCPv6
        Relay Agent") inside the DHCPv6 ADVERTISE message.





Zhou, et al.             Expires August 29, 2013               [Page 12]


Internet-Draft    Prefix Delegation Support for PMIPv6     February 2013


   8.   The mobile access gateway relays the DHCPv6 ADVERTISE message to
        the mobile router.

   9.   The mobile router sends the DHCPv6 REQUEST message with the
        IA_PD option(s) received from previous message to the mobile
        access gateway (which is acting as "DHCPv6 Relay Agent").

   10.  The DRA function on the mobile access gateway relays the DHCPv6
        REQUEST message to the DR.

   11.  The DR function on the local mobility anchor responds to the
        REQUEST from the mobile access gateway with a DHCPv6 REPLY
        message.

   12.  The RR function on the mobile router receives one or more IA_PD
        prefix(es) in the DHCPv6 REPLY message sent by the mobile access
        gateway.  The MAG sets up the forwarding for the delegated
        prefixes.  The delegated prefixes are reachable over the MN-MAG
        interface with the MR's link-local address, or home address as
        the next-hop destination.

4.4.2.  Refreshing the Delegated Prefix in Proxy Mobile IPv6

   When the mobile router sends DHCPv6 Renew messages to extend the
   lifetime of the delegated prefix, these messages are also intercepted
   by the mobile access gateway (acting as "DHCPv6 Relay Agent") and are
   relayed to the local mobility anchor (which is acting as "Delegating
   Router").

4.4.3.  Deletion of the Delegated Prefix in Proxy Mobile IPv6

   If the lifetime of the delegated prefix (included in the IA_PD Prefix
   Option carried by the DHCPv6 Reply message) is set to zero, the
   mobile access gateway (which is acting as "DHCPv6 Relay Agent") MUST
   send a proxy binding update message to remove the selective binding
   for that delegated mobile network prefix.  If the request is for
   remove the delegeted mobile network prefix only, the proxy binding
   update message with the lifetime value of (0) MUST NOT include either
   IPv6 Home Network Prefix option [RFC5213] or IPv4 Home Address
   Request option [RFC5844].











Zhou, et al.             Expires August 29, 2013               [Page 13]


Internet-Draft    Prefix Delegation Support for PMIPv6     February 2013


5.  Mobile Access Gateway Operation

5.1.  Extension to Binding Update List Entry Data Structure

   In order to support this specification, the conceptual Binding Update
   List Entry (BULE) data structure needs to be extended with a new
   prefix information field.  This field is used to store the delegated
   IPv4/IPv6 mobile network prefix assigned to the mobile router, which
   is included in the proxy binding acknowledgment.

5.2.  Forwarding

   Forwarding packets sent to the MR's delegated mobile network prefix:

   o  On receiving a packet from the bi-directional tunnel established
      with the local mobility anchor, the mobile access gateway MUST
      first decapsulate the packet (removing the outer header) and then
      use the destination address of the (inner) packet to forward it on
      the interface through which the destination delegated mobile
      network prefix is reachable.

   Forwarding packets sent by the mobile router:

   o  On receiving packets from a mobile router connected to one access
      link, the mobile access gateway MUST ensure that there is an
      established binding for the mobile router and the local mobility
      anchor for the source delegated mobile network prefix before
      tunneling the packet to the MR's local mobility anchor.

   Other considerations from Section 6.10.5 of [RFC5213] also apply
   here.

5.3.  Handover

   When the mobile router moves from the previously attached mobile
   access gateway to the target MAG, the newly attached mobile access
   gateway MAY know the delegated mobile network prefix(es) which were
   assigned to the mobile router during the previous attachment.  It is
   out of scope of this specification how the new mobile access gateway
   could obtain the previously assigned delegated mobile network
   prefix(es) (e.g., from some network element such as the previous
   MAG).  After moving to the new MAG, a proxy binding update message
   including the assigned delegated mobile network prefix(es) (if
   available) MUST be sent by the MAG to the LMA.  The local mobility
   anchor MUST check the delegated mobile network prefix(es) included in
   the PBU message and return the same assigned delegated mobile network
   prefix(es) in the proxy binding acknowledgment message.  If the
   previously assigned mobile network prefix(es) are not known by new



Zhou, et al.             Expires August 29, 2013               [Page 14]


Internet-Draft    Prefix Delegation Support for PMIPv6     February 2013


   MAG, the mobile network prefix(es) MUST be set to unspecified address
   "::" and the prefix length MUST be set to 0 in the proxy binding
   update message sent by the new mobile access gateway to the local
   mobility anchor.  In this case, the local mobility anchor MUST return
   the same previously assigned mobile network prefix(es) in proxy
   binding acknowledgment message.













































Zhou, et al.             Expires August 29, 2013               [Page 15]


Internet-Draft    Prefix Delegation Support for PMIPv6     February 2013


6.  Local Mobility Anchor Operation

6.1.  Extension to Binding Cache Entry Data Structure

   In order to support this specification, the conceptual Binding Cache
   Entry (BCE) data structure needs to be extended with a new prefix
   information field.  This field is used to store the IPv4/IPv6
   delegated mobile network prefix(es) assigned to the mobile router and
   included in the proxy binding update (as described in Section 4.2).

6.2.  Forwarding

   Intercepting packets sent to the MR's delegated mobile network
   prefix:

   o  When the local mobility anchor is serving the mobile router, it
      MUST be able to receive/intercept packets destined to the network
      behind the mobile router.  In order to receive these packets, the
      local mobility anchor MUST be the topological anchor of the MR's
      delegated mobile network prefix(es).

   Forwarding packets to the mobile router:

   o  On receiving a packet from a correspondent node with the
      destination address matching the MR's delegated mobile network
      prefix(es), the local mobility anchor MUST forward the packet
      through the bi-directional tunnel set up with the mobile router.

   Other considerations from Section 5.6.2 of [RFC5213] also apply here.






















Zhou, et al.             Expires August 29, 2013               [Page 16]


Internet-Draft    Prefix Delegation Support for PMIPv6     February 2013


7.  Security Considerations

   This document describes extensions to the Proxy Mobile IPv6 protocol
   for supporting network mobility using DHCPv6-based Prefix Delegation.
   The security considerations for DHCPv6 described in the "Security
   Considerations" section of the DHCPv6 base specification [RFC3315],
   the "Security Considerations" of the DHCPv6 Prefix Delegation
   specification [RFC3633], and the security considerations from the
   base Proxy Mobile IPv6 [RFC5213] apply when using the extensions
   defined in this document.

   The use of DHCPv6, as described in this document, requires message
   integrity protection and source authentication.  The IPsec security
   mechanism mandated by Proxy Mobile IPv6 [RFC5213] MUST be used to
   secure the DHCPv6 signaling between the mobile access gateway and the
   local mobility anchor.  In the following, we describe the Security
   Policy Database (SPD) and Security Association Database (SAD) entries
   necessary to protect the DHCPv6 signaling.  We use the same format
   used by [RFC4877].  The SPD and SAD entries are only example
   configurations.  A particular mobile access gateway implementation
   and a local mobility anchor implementation could configure different
   SPD and SAD entries as long as they provide the required security of
   the DHCPv6 signaling messages.

   For the examples described in this document, a mobile access gateway
   with address "mag_address_1", and a local mobility anchor with
   address "lma_address_1" are assumed.

      mobile access gateway SPD-S:
        - IF local_address = mag_address_1 &
             remote_address = lma_address_1 & proto = UDP &
             local_port = any & remote_port = DHCP
          Then use SA1 (OUT) and SA2 (IN)

      mobile access gateway SAD:
        - SA1(OUT, spi_a, lma_address_1, ESP, TRANSPORT):
              local_address = mag_address_1 &
              remote_address = lma_address_1 &
              proto = UDP & remote_port = DHCP
        - SA2(IN, spi_b, mag_address_1, ESP, TRANSPORT):
              local_address = lma_address_1 &
              remote_address = mag_address_1 &
              proto = UDP & local_port = DHCP

      local mobility anchor SPD-S:
        - IF local_address = lma_address_1 &
             remote_address = mag_address_1 & proto = UDP &
             local_port = DHCP & remote_port = any



Zhou, et al.             Expires August 29, 2013               [Page 17]


Internet-Draft    Prefix Delegation Support for PMIPv6     February 2013


          Then use SA2 (OUT) and SA1 (IN)

      local mobility anchor SAD:
        - SA2(OUT, spi_b, mag_address_1, ESP, TRANSPORT):
              local_address = lma_address_1 &
              remote_address = mag_address_1 &
              proto = UDP & local_port = DHCP
        - SA1(IN, spi_a, lma_address_1, ESP, TRANSPORT):
              local_address = mag_address_1 &
              remote_address = lma_address_1 &
              proto = UDP & remote_port = DHCP








































Zhou, et al.             Expires August 29, 2013               [Page 18]


Internet-Draft    Prefix Delegation Support for PMIPv6     February 2013


8.  IANA Considerations

   This document requires the following IANA action.

   o  Action-1: This specification defines a new Mobility Header option,
      Delegated Mobile Network Prefix option.  This mobility option is
      described in Section 3.1.  The Type value for this option needs to
      be assigned from the same numbering space as allocated for the
      other mobility options, as defined in [RFC6275].










































Zhou, et al.             Expires August 29, 2013               [Page 19]


Internet-Draft    Prefix Delegation Support for PMIPv6     February 2013


9.  Acknowledgments

   The work of Carlos J. Bernardos has also been partially supported by
   the European Community's Seventh Framework Programme (FP7-ICT-2009-5)
   under grant agreement n. 258053 (MEDIEVAL project) and by the
   Ministry of Science and Innovation of Spain under the QUARTET project
   (TIN2009-13992-C02-01).












































Zhou, et al.             Expires August 29, 2013               [Page 20]


Internet-Draft    Prefix Delegation Support for PMIPv6     February 2013


10.  References

10.1.  Normative References

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

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

   [RFC3315]  Droms, R., Bound, J., Volz, B., Lemon, T., Perkins, C.,
              and M. Carney, "Dynamic Host Configuration Protocol for
              IPv6 (DHCPv6)", RFC 3315, July 2003.

   [RFC3633]  Troan, O. and R. Droms, "IPv6 Prefix Options for Dynamic
              Host Configuration Protocol (DHCP) version 6", RFC 3633,
              December 2003.

   [RFC3963]  Devarapalli, V., Wakikawa, R., Petrescu, A., and P.
              Thubert, "Network Mobility (NEMO) Basic Support Protocol",
              RFC 3963, January 2005.

   [RFC4877]  Devarapalli, V. and F. Dupont, "Mobile IPv6 Operation with
              IKEv2 and the Revised IPsec Architecture", RFC 4877,
              April 2007.

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

   [RFC5844]  Wakikawa, R. and S. Gundavelli, "IPv4 Support for Proxy
              Mobile IPv6", RFC 5844, May 2010.

   [RFC6275]  Perkins, C., Johnson, D., and J. Arkko, "Mobility Support
              in IPv6", RFC 6275, July 2011.

   [RFC6276]  Droms, R., Thubert, P., Dupont, F., Haddad, W., and C.
              Bernardos, "DHCPv6 Prefix Delegation for Network Mobility
              (NEMO)", RFC 6276, July 2011.

   [RFC6603]  Korhonen, J., Savolainen, T., Krishnan, S., and O. Troan,
              "Prefix Exclude Option for DHCPv6-based Prefix
              Delegation", RFC 6603, May 2012.

10.2.  Informative References

   [RFC3753]  Manner, J. and M. Kojo, "Mobility Related Terminology",
              RFC 3753, June 2004.




Zhou, et al.             Expires August 29, 2013               [Page 21]


Internet-Draft    Prefix Delegation Support for PMIPv6     February 2013


   [RFC6656]  Johnson, R., Kinnear, K., and M. Stapp, "Description of
              Cisco Systems' Subnet Allocation Option for DHCPv4",
              RFC 6656, July 2012.
















































Zhou, et al.             Expires August 29, 2013               [Page 22]


Internet-Draft    Prefix Delegation Support for PMIPv6     February 2013


Authors' Addresses

   Xingyue Zhou
   ZTE Corporation
   No.50 Software Avenue, Yuhuatai District
   Nanjing
   China

   Phone: +86-25-8801-4634
   Email: zhou.xingyue@zte.com.cn


   Jouni Korhonen
   Nokia Siemens Networks
   Linnoitustie 6
   Espoo  FIN-02600
   Finland

   Email: jouni.nospam@gmail.com


   Carl Williams
   Consultant
   San Jose, CA
   USA

   Email: carlw@mcsr-labs.org


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

   Email: sgundave@cisco.com


   Carlos J. Bernardos
   Universidad Carlos III de Madrid
   Av. Universidad, 30
   Leganes, Madrid  28911
   Spain

   Phone: +34 91624 6236
   Email: cjbc@it.uc3m.es
   URI:   http://www.it.uc3m.es/cjbc/




Zhou, et al.             Expires August 29, 2013               [Page 23]


Html markup produced by rfcmarkup 1.129b, available from https://tools.ietf.org/tools/rfcmarkup/