draft-ietf-netlmm-proxymip6-00.txt   draft-ietf-netlmm-proxymip6-01.txt 
NETLMM WG S. Gundavelli NETLMM WG S. Gundavelli
Internet-Draft K. Leung Internet-Draft K. Leung
Intended status: Standards Track Cisco Intended status: Standards Track Cisco
Expires: October 10, 2007 V. Devarapalli Expires: December 20, 2007 V. Devarapalli
Azaire Networks Azaire Networks
K. Chowdhury K. Chowdhury
Starent Networks Starent Networks
B. Patil B. Patil
Nokia Siemens Networks Nokia Siemens Networks
April 08, 2007 June 18, 2007
Proxy Mobile IPv6 Proxy Mobile IPv6
draft-ietf-netlmm-proxymip6-00.txt draft-ietf-netlmm-proxymip6-01.txt
Status of this Memo Status of this Memo
By submitting this Internet-Draft, each author represents that any By submitting this Internet-Draft, each author represents that any
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have been or will be disclosed, and any of which he or she becomes have been or will be disclosed, and any of which he or she becomes
aware will be disclosed, in accordance with Section 6 of BCP 79. aware will be disclosed, in accordance with Section 6 of BCP 79.
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skipping to change at page 1, line 40 skipping to change at page 1, line 40
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The list of current Internet-Drafts can be accessed at The list of current Internet-Drafts can be accessed at
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This Internet-Draft will expire on October 10, 2007. This Internet-Draft will expire on December 20, 2007.
Copyright Notice Copyright Notice
Copyright (C) The IETF Trust (2007). Copyright (C) The IETF Trust (2007).
Abstract Abstract
Host based IPv6 mobility is specified in Mobile IPv6 base Host based IPv6 mobility is specified in Mobile IPv6 base
specification [RFC3775]. In that model, the mobile node is specification [RFC3775]. In that model, the mobile node is
responsible for doing the signaling to its home agent to enable responsible for doing the signaling to its home agent to enable
skipping to change at page 2, line 22 skipping to change at page 2, line 22
mobility agent in the network which manages the mobility for a mobile mobility agent in the network which manages the mobility for a mobile
node is the reason for referring to this protocol as Proxy Mobile node is the reason for referring to this protocol as Proxy Mobile
IPv6. IPv6.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Conventions & Terminology . . . . . . . . . . . . . . . . . . 5 2. Conventions & Terminology . . . . . . . . . . . . . . . . . . 5
2.1. Conventions used in this document . . . . . . . . . . . . 5 2.1. Conventions used in this document . . . . . . . . . . . . 5
2.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . 5 2.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . 5
3. Proxy Mobile IPv6 Protocol Overview . . . . . . . . . . . . . 8 3. Proxy Mobile IPv6 Protocol Overview . . . . . . . . . . . . . 7
4. Proxy Mobile IPv6 Protocol Security . . . . . . . . . . . . . 11 4. Proxy Mobile IPv6 Protocol Security . . . . . . . . . . . . . 11
4.1. Peer Authorization Database Entries . . . . . . . . . . . 12 4.1. Peer Authorization Database Entries . . . . . . . . . . . 11
4.2. Security Policy Database Entries . . . . . . . . . . . . . 12 4.2. Security Policy Database Entries . . . . . . . . . . . . . 12
5. Local Mobility Anchor Operation . . . . . . . . . . . . . . . 13 5. Local Mobility Anchor Operation . . . . . . . . . . . . . . . 13
5.1. Extensions to Binding Cache Conceptual Data Structure . . 14 5.1. Extensions to Binding Cache Conceptual Data Structure . . 14
5.2. Bi-Directional Tunnel Management . . . . . . . . . . . . . 15 5.2. Bi-Directional Tunnel Management . . . . . . . . . . . . . 14
5.3. Routing Considerations . . . . . . . . . . . . . . . . . . 16 5.3. Routing Considerations . . . . . . . . . . . . . . . . . . 15
5.4. Local Mobility Anchor Address Discovery . . . . . . . . . 17 5.4. Local Mobility Anchor Address Discovery . . . . . . . . . 16
5.5. Sequence Number and Time-Stamps for Message Ordering . . . 17 5.5. Sequence Number and Time-Stamps for Message Ordering . . . 16
5.6. Route Optimizations Considerations . . . . . . . . . . . . 19 5.6. Route Optimizations Considerations . . . . . . . . . . . . 17
5.7. Mobile Prefix Discovery Considerations . . . . . . . . . . 19 5.7. Mobile Prefix Discovery Considerations . . . . . . . . . . 18
5.8. Local Mobility Anchor Operational Summary . . . . . . . . 19 5.8. Signaling Considerations . . . . . . . . . . . . . . . . . 18
5.8.1. Initial Proxy Binding Registration . . . . . . . . . . 18
5.8.2. Extending the binding lifetime . . . . . . . . . . . . 20
5.8.3. De-registration of the binding . . . . . . . . . . . . 20
5.9. Local Mobility Anchor Operational Summary . . . . . . . . 20
6. Mobile Access Gateway Operation . . . . . . . . . . . . . . . 21 6. Mobile Access Gateway Operation . . . . . . . . . . . . . . . 21
6.1. Address Configuration Models . . . . . . . . . . . . . . . 22 6.1. Supported Access Link Types . . . . . . . . . . . . . . . 21
6.2. Conceptual Data Structures . . . . . . . . . . . . . . . . 23 6.2. Supported Home Network Prefix Models . . . . . . . . . . . 22
6.3. Access Authentication . . . . . . . . . . . . . . . . . . 23 6.3. Supported Address Configuration Models . . . . . . . . . . 22
6.4. Home Network Emulation . . . . . . . . . . . . . . . . . . 24 6.4. Access Authentication & Mobile Node Identification . . . . 23
6.5. Link-Local and Global Address Uniqueness . . . . . . . . . 24 6.5. Mobile Node's Policy Profile . . . . . . . . . . . . . . . 23
6.6. Tunnel Management . . . . . . . . . . . . . . . . . . . . 25 6.6. Conceptual Data Structures . . . . . . . . . . . . . . . . 24
6.7. Routing Considerations . . . . . . . . . . . . . . . . . . 26 6.7. Home Network Emulation . . . . . . . . . . . . . . . . . . 24
6.8. Interaction with DHCP Relay Agent . . . . . . . . . . . . 27 6.7.1. Home Network Prefix Renumbering . . . . . . . . . . . 25
6.9. Mobile Node Detachment Detection and Resource Cleanup . . 27 6.8. Link-Local and Global Address Uniqueness . . . . . . . . . 26
6.10. Coexistence with Mobile Nodes using Host-based Mobility . 28 6.9. Signaling Considerations . . . . . . . . . . . . . . . . . 27
6.11. Mobile Access Gateway Operation Summary . . . . . . . . . 29 6.9.1. Initial Attachment and binding registration . . . . . 27
7. Mobile Node Operation . . . . . . . . . . . . . . . . . . . . 31 6.9.2. Extending the binding lifetime . . . . . . . . . . . . 28
7.1. Booting up in a Proxy Mobile IPv6 Domain . . . . . . . . . 32 6.9.3. De-registration of the binding . . . . . . . . . . . . 28
7.2. Roaming in the Proxy Mobile IPv6 Network . . . . . . . . . 33 6.10. Routing Considerations . . . . . . . . . . . . . . . . . . 28
7.3. IPv6 Host Protocol Parameters . . . . . . . . . . . . . . 33 6.10.1. Transport Network . . . . . . . . . . . . . . . . . . 29
8. Message Formats . . . . . . . . . . . . . . . . . . . . . . . 34 6.10.2. Tunneling & Encapsulation Modes . . . . . . . . . . . 29
8.1. Proxy Binding Update . . . . . . . . . . . . . . . . . . . 35 6.10.3. Routing State . . . . . . . . . . . . . . . . . . . . 30
8.2. Proxy Binding Acknowledgment . . . . . . . . . . . . . . . 35 6.10.4. Local Routing . . . . . . . . . . . . . . . . . . . . 31
8.3. Home Network Prefix Option . . . . . . . . . . . . . . . . 36 6.10.5. Tunnel Management . . . . . . . . . . . . . . . . . . 31
8.4. Time Stamp Option . . . . . . . . . . . . . . . . . . . . 38 6.10.6. Forwarding Rules . . . . . . . . . . . . . . . . . . . 31
8.5. Status Codes . . . . . . . . . . . . . . . . . . . . . . . 38 6.11. Interaction with DHCP Relay Agent . . . . . . . . . . . . 32
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 39 6.12. Mobile Node Detachment Detection and Resource Cleanup . . 32
10. Security Considerations . . . . . . . . . . . . . . . . . . . 39 6.13. Allowing network access to other IPv6 nodes . . . . . . . 33
11. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 40 7. Mobile Node Operation . . . . . . . . . . . . . . . . . . . . 34
12. References . . . . . . . . . . . . . . . . . . . . . . . . . . 41 7.1. Booting up in a Proxy Mobile IPv6 Domain . . . . . . . . . 34
12.1. Normative References . . . . . . . . . . . . . . . . . . . 41 7.2. Roaming in the Proxy Mobile IPv6 Network . . . . . . . . . 35
12.2. Informative References . . . . . . . . . . . . . . . . . . 42 7.3. IPv6 Host Protocol Parameters . . . . . . . . . . . . . . 36
8. Message Formats . . . . . . . . . . . . . . . . . . . . . . . 37
8.1. Proxy Binding Update . . . . . . . . . . . . . . . . . . . 37
8.2. Proxy Binding Acknowledgment . . . . . . . . . . . . . . . 38
8.3. Home Network Prefix Option . . . . . . . . . . . . . . . . 39
8.4. Time Stamp Option . . . . . . . . . . . . . . . . . . . . 40
8.5. Status Codes . . . . . . . . . . . . . . . . . . . . . . . 41
9. Protocol Configuration Variables . . . . . . . . . . . . . . . 42
10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 42
11. Security Considerations . . . . . . . . . . . . . . . . . . . 42
12. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 44
13. References . . . . . . . . . . . . . . . . . . . . . . . . . . 44
13.1. Normative References . . . . . . . . . . . . . . . . . . . 44
13.2. Informative References . . . . . . . . . . . . . . . . . . 45
Appendix A. Proxy Mobile IPv6 interactions with AAA Appendix A. Proxy Mobile IPv6 interactions with AAA
Infrastructure . . . . . . . . . . . . . . . . . . . 43 Infrastructure . . . . . . . . . . . . . . . . . . . 46
Appendix B. Supporting Shared-Prefix Model using DHCPv6 . . . . . 43 Appendix B. Supporting Shared-Prefix Model using DHCPv6 . . . . . 46
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 44 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 47
Intellectual Property and Copyright Statements . . . . . . . . . . 46 Intellectual Property and Copyright Statements . . . . . . . . . . 49
1. Introduction 1. Introduction
Mobile IPv6 [RFC-3775] is the enabler for IPv6 mobility. It requires Mobile IPv6 [RFC-3775] is the enabler for IPv6 mobility. It requires
Mobile IPv6 client functionality in the IPv6 stack of a mobile node. Mobile IPv6 client functionality in the IPv6 stack of a mobile node.
Signaling between the MN and HA enables the creation and maintenance Signaling between the mobile node and home agent enables the creation
of a binding between the MNs home address and care-of-address. and maintenance of a binding between the mobile node's home address
Mobile IPv6 has been designed to be an integral part of the IPv6 and care-of-address. Mobile IPv6 has been designed to be an integral
stack in a host. However there exist IPv6 stacks today that do not part of the IPv6 stack in a host. However there exist IPv6 stacks
have Mobile IPv6 functionality and there would likely be IPv6 stacks today that do not have Mobile IPv6 functionality and there would
without MIPv6 functionality in the future as well. It is desirable likely be IPv6 stacks without Mobile IPv6 client functionality in the
to support IP mobility for all hosts irrespective of the presence or future as well. It is desirable to support IP mobility for all hosts
absence of mobile IPv6 functionality in the IPv6 stack. irrespective of the presence or absence of mobile IPv6 functionality
in the IPv6 stack.
It is possible to support mobility for IPv6 nodes by extending Mobile It is possible to support mobility for IPv6 nodes by extending Mobile
IPv6 [RFC-3775] signaling and reusing the home agent via a proxy IPv6 [RFC-3775] signaling and reusing the home agent via a proxy
mobility agent in the network. This approach to supporting mobility mobility agent in the network. This approach to supporting mobility
does not require the mobile node to be involved in the signaling does not require the mobile node to be involved in the signaling
required for mobility management. The proxy agent in the network required for mobility management. The proxy mobility agent in the
performs the signaling and does the mobility management on behalf of network performs the signaling and does the mobility management on
the mobile node. Because of the use and extension of Mobile IPv6 behalf of the mobile node. Because of the use and extension of
signaling and home agent functionality, it is referred to as Proxy Mobile IPv6 signaling and home agent functionality, it is referred to
Mobile IPv6 (PMIP6) in the context of this document. as Proxy Mobile IPv6 (PMIP6) in the context of this document.
Network deployments which are designed to support mobility would be Network deployments which are designed to support mobility would be
agnostic to the capability in the IPv6 stack of the nodes which it agnostic to the capability in the IPv6 stack of the nodes which it
serves. IP mobility for nodes which have mobile IP client serves. IP mobility for nodes which have mobile IP client
functionality in the IPv6 stack as well as those hosts which do not, functionality in the IPv6 stack as well as those hosts which do not,
would be supported by enabling PMIP6 protocol functionality in the would be supported by enabling Proxy Mobile IPv6 protocol
network. The advantages of developing a network based mobility functionality in the network. The advantages of developing a network
protocol based on Mobile IPv6 are: based mobility protocol based on Mobile IPv6 are:
o Reuse of home agent functionality and the messages/format used in o Reuse of home agent functionality and the messages/format used in
mobility signaling. Mobile IPv6 is a mature protocol with several mobility signaling. Mobile IPv6 is a mature protocol with several
implementations that have been through interoperability testing. implementations that have been through interoperability testing.
o A common home agent would serve as the mobility agent for all o A common home agent would serve as the mobility agent for all
types of IPv6 nodes. types of IPv6 nodes.
o Addresses a real deployment need. o Addresses a real deployment need.
The problem statement and the need for a network based mobility The problem statement and the need for a network based mobility
protocol solution has been documented in protocol solution has been documented in [RFC-4830]. Proxy Mobile
[draft-ietf-netlmm-nohost-ps-05.txt]. PMIP6 is a solution that IPv6 is a solution that addresses these issues and requirements.
addresses these issues and requirements.
The IP Mobility protocols designed in the IETF so far involve the
host in mobility management. There are some deployment scenarios
where a network-based mobility management protocol is considered
appropriate. The advantages to using a network-based mobility
protocol include avoiding tunneling overhead over the air and support
for hosts that do not implement any mobility management protocol.
The document describes a network-based mobility management protocol
based on Mobile IPv6. it is called Proxy Mobile IPv6 (PMIPv6). One
of the most important design considerations behind PMIPv6 has been to
re-use as much as possible from the existing mobility protocols.
There are many advantages to develop a protocol based on Mobile IPv6.
Mobile IPv6 is a very mature mobility protocol for IPv6. There have
been many implementations and inter-operability events where Mobile
IPv6 has been tested. There also numerous specifications enhancing
Mobile IPv6 that can be re-used. Further, the Proxy MIPv6 solution
described in this document allows the same Home Agent to provide
mobility to hosts that use Mobile IPv6 and hosts that do not use any
mobility management protocol. Proxy Mobile IPv6 provides solution to
a real deployment problem.
The specific details related to enabling IPv4 home address mobility
for the mobile node and the details related to supporting IPv4
transport network are covered in the companion document.
2. Conventions & Terminology 2. Conventions & Terminology
2.1. Conventions used in this document 2.1. Conventions used in this document
The keywords "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The keywords "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" used in "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" used in
this document are to be interpreted as described in RFC 2119. this document are to be interpreted as described in RFC 2119.
2.2. Terminology 2.2. Terminology
All the general mobility related terms used in this document are to All the general mobility related terms used in this document are to
be interpreted as defined in the Mobile IPv6 base specification [RFC- be interpreted as defined in the Mobile IPv6 base specification [RFC-
3775]. 3775].
This document adopts the terms, Local Mobility Anchor (LMA) and This document adopts the terms, Local Mobility Anchor (LMA) and
Mobile Access Gateway (MAG) from the NETLMM Goals document Mobile Access Gateway (MAG) from the NETLMM Goals document [RFC-
[draft-ietf-netlmm-nohost-req-05.txt]. It further provides the 4831]. This document also provides the following context specific
following context specific explanation to these terms, specific to explanation to the following terms used in this document.
this solution document.
Proxy Mobile IPv6 Domain (PMIPv6-Domain)
Proxy Mobile IPv6 domain refers to the network where the mobility
management of a mobile node is handled using Proxy Mobile IPv6
protocol as defined in this specification. The Proxy Mobile IPv6
domain includes local mobility anchors and mobile access gateways
between which security associations can be setup and authorization
for sending Proxy Binding Updates on behalf of the mobile nodes
can be ensured.
Local Mobility Anchor (LMA) Local Mobility Anchor (LMA)
Local Mobility Anchor is the home agent for the mobile node in the Local Mobility Anchor is the home agent for the mobile node in the
Proxy Mobile IPv6 domain. It is the topological anchor point for Proxy Mobile IPv6 domain. It is the topological anchor point for
the mobile node's home prefix and is the entity that manages the the mobile node's home network prefix and is the entity that
mobile node's reachability state. It is important to understand manages the mobile node's reachability state. It is important to
that the LMA has the functional capabilities of a home agent as understand that the local mobility anchor has the functional
defined in Mobile IPv6 base specification [RFC-3775] and with the capabilities of a home agent as defined in Mobile IPv6 base
additional required capabilities for supporting Proxy Mobile IPv6 specification [RFC-3775] and with the additional required
as defined in this specification. capabilities for supporting Proxy Mobile IPv6 protocol as defined
in this specification.
Proxy Mobile Agent (PMA)
Proxy mobility agent is a function that manages the mobility Mobile Access Gateway (MAG)
Mobile Access Gateway is a function that manages the mobility
related signaling for a mobile node that is attached to its access related signaling for a mobile node that is attached to its access
link. It is responsible for tracking the mobile node's attachment link. It is responsible for tracking the mobile node's attachment
to the link and for signaling the mobile node's local mobility to the link and for signaling the mobile node's local mobility
anchor. anchor.
Mobile Access Gateway (MAG)
It is the entity where the Proxy Mobile Agent function resides.
Mobile Node (MN) Mobile Node (MN)
Through out this document, the term mobile node is used to refer Through out this document, the term mobile node is used to refer
to an IP node whose mobility is provided by the network. The to an IP node whose mobility is managed by the network. The
mobile node may be operating in IPv6 mode, IPv4 mode or in IPv4/ mobile node may be operating in IPv6 mode, IPv4 mode or in IPv4/
IPv6 dual mode. The mobile node is not required to participate in IPv6 dual mode. The mobile node is not required to participate in
any mobility related signaling for achieving mobility for an IP any mobility related signaling for achieving mobility for an IP
address that is obtained in that local domain. This document address that is obtained in that local domain. This document
further uses explicit text when referring to a mobile node that is further uses explicit text when referring to a mobile node that is
involved in mobility related signaling as per Mobile IPv6 involved in mobility related signaling as per Mobile IPv6
specification [RFC-3775]. The mobile node's capability or its specification [RFC-3775].
involvement in any mobility related signaling for obtaining
mobility for an address that is obtained outside the current proxy
mobile IPv6 domain, is not relevant in the context of this
document and this definition of the Mobile Node shall survive.
Mobile Node's Home Address (MN-HoA) LMA Address (LMAA)
MN-HoA is the home address of a mobile node in a Proxy Mobile IPv6 The address that is configured on the interface of the local
domain. It is an address obtained by the mobile node in that mobility anchor and is the transport endpoint of the tunnel
domain. The mobile node can continue to use this address as long between the local mobility anchor and the mobile access gateway.
as it is attached to the network that is in the scope of that This is the address to where the mobile access gateway sends the
Proxy Mobile IPv6 domain. When supporting IPv4 address mobility Proxy Binding Update messages. When supporting IPv4 traversal,
for a mobile node, the term, IPv4 MN-HoA is used to refer to the i.e. when the network between the local mobility anchor and the
IPv4 address of the mobile node. mobile access gateway is an IPv4 network, this address will be an
IPv4 address and will be referred to as IPv4-LMAA, as specified in
[ID-IPV4-PMIP6].
Proxy Care-of Address (Proxy-CoA) Proxy Care-of Address (Proxy-CoA)
Proxy-CoA is the address configured on the interface of the mobile Proxy-CoA is the address configured on the interface of the mobile
access gateway and is the transport endpoint of the tunnel between access gateway and is the transport endpoint of the tunnel between
the local mobility anchor and the mobile access gateway. The the local mobility anchor and the mobile access gateway. The
local mobility anchor views this address as the Care-of Address of local mobility anchor views this address as the Care-of Address of
the mobile node and registers it in the Binding Cache entry for the mobile node and registers it in the Binding Cache entry for
that mobile node. When the transport network between the mobile that mobile node. When the transport network between the mobile
access gateway and the local mobility anchor is an IPv4 network access gateway and the local mobility anchor is an IPv4 network
and if the care-of address that is registered at the local and if the care-of address that is registered at the local
mobility anchor is an IPv4 address, the term, IPv4 Proxy-CoA is mobility anchor is an IPv4 address, the term, IPv4-Proxy-CoA is
used. used, as defined in [ID-IPV4-PMIP6].
LMA Address (LMAA)
The address that is configured on the interface of the local Mobile Node's Home Address (MN-HoA)
mobility anchor and is the transport endpoint of the tunnel MN-HoA is the home address of a mobile node in a Proxy Mobile IPv6
between the local mobility anchor and the mobile access gateway. domain. It is an address obtained by the mobile node in that
This is the address to where the mobile access gateway sends the domain. The mobile node can continue to use this address as long
Proxy Binding Update messages. When supporting IPv4 traversal, as it is attached to the network that is in the scope of that
i.e. when the network between the local mobility anchor and the Proxy Mobile IPv6 domain.
mobile access gateway is an IPv4 network, this address will be an
IPv4 address and will be referred to as IPv4 LMAA.
Proxy Mobile IPv6 Domain (PMIPv6-Domain) Mobile Node's Home Network Prefix (MN-HNP)
It is a localized mobility management domain. It is a portion of This is the on-link IPv6 prefix that the mobile node always sees
the access network where the mobility management of a mobile node in the Proxy Mobile IPv6 domain. The home network prefix is
is handled using Proxy Mobile IPv6 protocol as defined in this topologically anchored at the mobile node's local mobility anchor.
specification. The mobile node configures its interface with an address from this
prefix.
Mobile Node's Home Link Mobile Node's Home Link
This is the link on which the mobile node obtained its initial This is the link on which the mobile node obtained its initial
address configuration after it moved into that Proxy Mobile IPv6 address configuration after it moved into that Proxy Mobile IPv6
domain. This is the link that conceptually follows the mobile domain. This is the link that conceptually follows the mobile
node. The network will ensure the mobile node always sees this node. The network will ensure the mobile node always sees this
link with respect to the layer-3 network configuration, on any link with respect to the layer-3 network configuration, on any
access link that it attaches to in that proxy mobile IPv6 domain. access link that it attaches to in that proxy mobile IPv6 domain.
Mobile Node's Home Network Prefix (MN-HNP)
This is the on-link prefix that the mobile always sees in the
Proxy Mobile IPv6 domain. The home network prefix is
topologically anchored at the mobile's local mobility anchor. The
mobile node configures its interface with an address from this
prefix. When supporting IPv4 home address mobility, the term,
IPv4 Home Network refers to the mobile node's IPv4 home prefix and
the term, Home Network always refers to the IPv6 home network
prefix.
Mobile Node Identifier (MN-Identifier) Mobile Node Identifier (MN-Identifier)
The identity of the mobile node that is presented to the network The identity of the mobile node that is presented to the network
as part of the access authentication. This is typically an as part of the access authentication. This is typically an
identifier such as Mobile Node NAI [RFC-4283] any other type of identifier such as Mobile Node NAI [RFC-4283], or any other type
identifier which may be specific to the access technology. of identifier which may be specific to the access technology.
Proxy Binding Update (PBU) Proxy Binding Update (PBU)
A signaling message sent by the mobile access gateway to a mobile A signaling message sent by the mobile access gateway to a mobile
node's local mobility anchor for establishing a binding between node's local mobility anchor for establishing a binding between
the mobile node's MN-HoA and the Proxy-CoA. the mobile node's MN-HoA and the Proxy-CoA.
Proxy Binding Acknowledgement (PBA) Proxy Binding Acknowledgement (PBA)
A response message sent by a local mobility anchor in response to A response message sent by a local mobility anchor in response to
a Proxy Binding Update message that it received from a mobile a Proxy Binding Update message that it received from a mobile
access gateway. access gateway.
3. Proxy Mobile IPv6 Protocol Overview 3. Proxy Mobile IPv6 Protocol Overview
This specification describes a network-based mobility management This specification describes a network-based mobility management
protocol. It is called Proxy Mobile IPv6 (PMIPv6) and is based on protocol. It is called Proxy Mobile IPv6 and is based on Mobile IPv6
Mobile IPv6 [RFC-3775]. This protocol is for providing network-based [RFC-3775]. This protocol is for providing network-based mobility
mobility management support to a mobile node, within a restricted and management support to a mobile node, within a restricted and
topologically localized portion of the network and with out requiring topologically localized portion of the network and with out requiring
the participation of the mobile node in any mobility related the participation of the mobile node in any mobility related
signaling. signaling.
Every mobile node that roams in a Proxy Mobile IPv6 domain, would Every mobile node that roams in a Proxy Mobile IPv6 domain, would
typically be identified by an identifier, such as MN-Identifier, and typically be identified by an identifier, MN-Identifier, and using
using that identifier the mobile node's policy profile can be that identifier the mobile node's policy profile can be obtained from
obtained from the policy store. The policy profile typically the policy store. The policy profile typically contains the
contains the provisioned network-based mobility service provisioned network-based mobility service characteristics and other
characterstics and other related parameters such as the mobile node's related parameters such as the mobile node's Identifier, local
home network prefix, permitted address configuration modes, roaming mobility anchor address, permitted address configuration modes,
policy and other parameters that are essential for providing network roaming policy and other parameters that are essential for providing
based mobility service. the network based mobility service.
Once a mobile node enters its Proxy Mobile IPv6 domain and performs Once a mobile node enters its Proxy Mobile IPv6 domain and performs
access authentication, the network will ensure the mobile node is access authentication, the network will ensure that the mobile node
always on its home network and further ensures the mobile node can is always on its home network and can obtain its home address on any
always obtain its home address on the access link and using any of access link using any of the address configuration procedures. In
the address configuration procedures. In other words, there is home other words, there is a home network prefix that is assigned to a
network prefix that is assigned for a mobile node and conceptually mobile node and conceptually that address always follows the mobile
that address always follows the mobile node, where ever it roams node, where ever it roams within that Proxy Mobile IPv6 domain. From
within that proxy mobile IPv6 domain. From the perspective of the the perspective of the mobile node, the entire Proxy Mobile IPv6
mobile node, the entire Proxy Mobile IPv6 domain appears as its home domain appears as its home link or a single link.
link or a single link.
+----+ +----+ +----+ +----+
|LMA1| |LMA2| |LMA1| |LMA2|
+----+ +----+ +----+ +----+
LMAA1---- | | ---- LMAA2 LMAA1 -> | | <-- LMAA2
| | | |
\\ // \\ \\ // \\
+--\\------------- //---\\----+ \\ // \\
\\ // \\
+---\\------------- //------\\----+
( \\ IPv4/IPv6 // \\ ) ( \\ IPv4/IPv6 // \\ )
( \\ Network // \\ ) ( \\ Network // \\ )
+-----\\--------//---------\\-+ +------\\--------//------------\\-+
\\ // \\ \\ // \\
\\ // \\ <--- Tunnel2
\\ // \\ \\ // \\
|-- Proxy-CoA1 |-- Proxy-CoA2 \\ // \\
+----+ +----+ Proxy-CoA1--> | | <-- Proxy-CoA2
[MN1].__.|MAG1|.__.[MN2] |MAG2|
+----+ +----+ +----+ +----+
| | |MAG1|-----[MN2] |MAG2|
| | +----+ | +----+
------------------- [MN5] | | |
| | MN-HoA1 --> | MN-HoA2 | <-- MN-HoA3
[MN3] [MN4] [MN1] [MN3]
Figure 1: Proxy Mobile IPv6 Domain Figure 1: Proxy Mobile IPv6 Domain
The Proxy Mobile IPv6 scheme introduces a new function, the mobile The Proxy Mobile IPv6 scheme introduces a new function, the mobile
access gateway. It is a function that is on the access link where access gateway. It is a function that is on the access link where
the mobile is anchored and does the mobility related signaling on the mobile node is anchored and does the mobility related signaling
behalf of the mobile node. From the perspective of the local on its behalf. From the perspective of the local mobility anchor,
mobility anchor, the mobile access gateway is a special element in the mobile access gateway is a special element in the network that is
the network that is authorized to send Mobile IPv6 signaling messages authorized to send Mobile IPv6 signaling messages on behalf of other
on behalf of a mobile node. mobile nodes.
When the mobile node attaches to an access link connected to the When the mobile node attaches to an access link connected to the
mobile access gateway, the mobile node presents its identity, MN- mobile access gateway, the mobile node presents its identity, MN-
Identifier, as part of the access access authentication procedure. Identifier, as part of the access authentication procedure. After a
After a successful access authentication, the mobile access gateway successful access authentication, the mobile access gateway obtains
obtains the mobile node's profile from the policy store, such as from the mobile node's profile from the policy store. The mobile access
a AAA infrastructure. The mobile access gatway would have all the gateway would have all the required information for it to emulate the
information for it to emulate the mobile node's home network on the mobile node's home network on the access link. It sends Router
access link. The mobile access gateway also starts sending periodic Advertisement messages to the mobile node on the access link
Router Advertisements to the mobile node advertising its home network advertising the mobile node's home network prefix as the hosted on-
prefix. link-prefix.
The mobile node on receiving these Router Advertisement messages on The mobile node on receiving these Router Advertisement messages on
the access link will attempt to configure its interface either using the access link will attempt to configure its interface either using
statefull or stateless address configuration modes, based on modes stateful or stateless address configuration modes, based on modes
that are permitted on that access link. At the end of a successful that are permitted on that access link. At the end of a successful
address configuration procedure, the mobile node would have obtained address configuration procedure, the mobile node would have obtained
an address from its home network prefix. If the mobile node is IPv4 an address from its home network prefix. If the mobile node is IPv4
capable and if network offers IPv4 network mobility for the mobile capable and if network offers IPv4 network mobility for the mobile
node, the mobile node would have obtained an IPv4 address as well. node, the mobile node would have obtained an IPv4 address as well.
The mobile node can be operating in IPv4-only mode, IPv6-only or in The mobile node can be operating in IPv4-only mode, IPv6-only or in
dual-mode and based on the services enabled for that mobile, the dual-mode and based on the services enabled for that mobile, the
mobility is enabled only for those address types. Also, the network mobility is enabled only for those address types. Also, the network
between the local mobility anchor and the mobile access gateway can between the local mobility anchor and the mobile access gateway can
be either IPv4, IPv6, IPv4 with NAT translation devices in the access be either IPv4, IPv6 or a private IPv4 with NAT translation devices.
network.
For updating the local mobility anchor about the current location of For updating the local mobility anchor about the current location of
the mobile node, the mobile access gateway sends a Proxy Binding the mobile node, the mobile access gateway sends a Proxy Binding
Update message to the mobile node's local mobility anchor. The Update message to the mobile node's local mobility anchor. The
message will have the mobile node's NAI identifier option and Home message will have the mobile node's NAI identifier option and other
Network Prefix Option and/or IPv4 Home Address option. The source required options. Upon accepting the Proxy Binding Update message,
address of that message will be the address of the mobile access the local mobility anchor sends a Proxy Binding Acknowledgment
gateway on its egress interface. Upon accepting the Proxy Binding message including the mobile node's home network prefix option. It
Update request, the local mobility anchor sends a Proxy Binding also sets up a route for the mobile node's home network prefix over
Acknowledgment message to the mobile access gateway. It also sets up the tunnel to the mobile access gateway.
a route to the mobile node's home network prefix over the tunnel and
sends Proxy Binding Acknowledgment message to the mobile access
gateway.
The mobile access gateway on receiving this Proxy Binding The mobile access gateway on receiving this Proxy Binding
Acknowledgment message sets up a tunnel to the local mobility anchor Acknowledgment message sets up a bi-directional tunnel to the local
and adds a default route over the tunnel to the local mobility mobility anchor and adds a default route over the tunnel to the local
anchor. All traffic from the mobile node gets routed to the mobile mobility anchor. All traffic from the mobile node gets routed to its
node's local mobility anchor over the tunnel. local mobility anchor through the bi-directional tunnel.
At this point, the mobile node has a valid home address from its home At this point, the mobile node has a valid address from its home
network prefix, at the current point of attachment. The serving network prefix, at the current point of attachment. The serving
mobile access gateway and the local mobility anchor also have proper mobile access gateway and the local mobility anchor also have proper
routing states for handling the traffic sent to and from the mobile routing states for handling the traffic sent to and from the mobile
node. node using an address from its home network prefix.
The local mobility anchor, being the topological anchor point for the The local mobility anchor, being the topological anchor point for the
mobile node's home network prefix, it receives any packet sent by any mobile node's home network prefix, receives any packet that is sent
corresponding node to the mobile node. Local mobility anchor by any corresponding node to the mobile node. Local mobility anchor
forwards the received packet to the mobile access gateway through the forwards the received packet to the mobile access gateway through the
tunnel. The mobile access gateway on other end of the tunnel, after bi-directional tunnel. The mobile access gateway on other end of the
receiving the packet removes the tunnel header and forwards the tunnel, after receiving the packet, removes the outer header and
packet on the access link to the mobile node. forwards the packet on the access link to the mobile node.
The mobile access gateway typically acts as a default router on the The mobile access gateway typically acts as a default router on the
access link and any packet that the mobile node sends to any access link and any packet that the mobile node sends to any
corresponding node is received by the mobile access gateway and it corresponding node is received by the mobile access gateway and it
forwards the packet to the local mobility anchor through the tunnel. forwards the packet to its local mobility anchor through the bi-
The local mobility anchor on the other end of the tunnel, after directional tunnel. The local mobility anchor on the other end of
receiving the packet removes the tunnel header and routes the packet the tunnel, after receiving the packet removes the outer header and
to the destination. routes the packet to the destination.
4. Proxy Mobile IPv6 Protocol Security 4. Proxy Mobile IPv6 Protocol Security
The signaling messages, Proxy Binding Update and Proxy Binding The signaling messages, Proxy Binding Update and Proxy Binding
Acknowledgement, exchanged between the mobile access gateway and the Acknowledgement, exchanged between the mobile access gateway and the
local mobility anchor are protected using IPsec and using the local mobility anchor are protected using IPsec and using the
established security association between them. The security established security association between them. The security
association of the specific mobile node for which the signaling association of the specific mobile node for which the signaling
message is initiated is not required for protecting these messages. message is initiated is not required for protecting these messages.
skipping to change at page 12, line 5 skipping to change at page 11, line 41
described in this document, the mobile node is not involved in described in this document, the mobile node is not involved in
creating security associations for protecting the signaling messages creating security associations for protecting the signaling messages
or sending binding updates. Therefore, this is not a concern. or sending binding updates. Therefore, this is not a concern.
However, the local mobility anchor MUST allow only authorized mobile However, the local mobility anchor MUST allow only authorized mobile
access gateways to create binding cache entries on behalf of the access gateways to create binding cache entries on behalf of the
mobile nodes. The actual mechanism by which the local mobility mobile nodes. The actual mechanism by which the local mobility
anchor verifies if a specific mobile access gateway is authorized to anchor verifies if a specific mobile access gateway is authorized to
send Proxy Binding Updates on behalf of a mobile node is outside the send Proxy Binding Updates on behalf of a mobile node is outside the
scope of this document. One possible way this could be achieved is scope of this document. One possible way this could be achieved is
sending a query to the policy store such as by using AAA sending a query to the policy store such as by using AAA
infrastrucure. infrastructure.
4.1. Peer Authorization Database Entries 4.1. Peer Authorization Database Entries
The following describes PAD entries on the mobile access gateway and The following describes PAD entries on the mobile access gateway and
the local mobility anchor. The PAD entries are only example the local mobility anchor. The PAD entries are only example
configurations. Note that the PAD is a logical concept and a configurations. Note that the PAD is a logical concept and a
particular mobile access gateway or a local mobility anchor particular mobile access gateway or a local mobility anchor
implementation can implement the PAD in an implementation specific implementation can implement the PAD in an implementation specific
manner. The PAD state may also be distributed across various manner. The PAD state may also be distributed across various
databases in a specific implementation. databases in a specific implementation.
skipping to change at page 13, line 20 skipping to change at page 13, line 7
Initiate using IDi = mag_1 to address lma_1 Initiate using IDi = mag_1 to address lma_1
local mobility anchor SPD-S: local mobility anchor SPD-S:
- IF local_address = lma_address_1 & - IF local_address = lma_address_1 &
remote_address = mag_address_1 & remote_address = mag_address_1 &
proto = MH & local_mh_type = BAck & remote_mh_type = BU proto = MH & local_mh_type = BAck & remote_mh_type = BU
Then use SA ESP transport mode Then use SA ESP transport mode
5. Local Mobility Anchor Operation 5. Local Mobility Anchor Operation
For supporting the Proxy Mobile IPv6 scheme defined in this document, For supporting the Proxy Mobile IPv6 scheme specified in this
the Mobile IPv6 home agent entity, defined in Mobile IPv6 document, the Mobile IPv6 home agent entity, defined in Mobile IPv6
specification [RFC-3775], needs some protocol enhancements. The specification [RFC-3775], needs some enhancements. The local
local mobility anchor is the functional entity with these mobility anchor is an entity that has the functional capabilities of
capabilities for supporting Proxy Mobile IPv6. This section a home agent and with the additional required capabilities for
describes the operational details of the local mobility anchor. supporting Proxy Mobile IPv6 protocol as defined in this
specification. This section describes the operational details of the
local mobility anchor.
The base Mobile IPv6 specification [RFC-3775], defines home agent and The base Mobile IPv6 specification [RFC-3775], defines home agent and
the mobile node as the two functional entities. The Proxy Mobile the mobile node as the two functional entities. The Proxy Mobile
IPv6 scheme introduces a new entity, the mobile access gateway. This IPv6 scheme introduces a new entity, the mobile access gateway. This
is the entity that will participate in the mobility related is the entity that will participate in the mobility related
signaling. From the perspective of the local mobility anchor, the signaling. From the perspective of the local mobility anchor, the
mobile access gateway is a special element in the network that has mobile access gateway is a special element in the network that has
the privileges to send mobility related signaling messages on behalf the privileges to send mobility related signaling messages on behalf
of the mobile node. Typically, the local mobility anchor is of the mobile node. Typically, the local mobility anchor is
provisioned with the list of mobile access gateways authorized to provisioned with the list of mobile access gateways authorized to
skipping to change at page 14, line 9 skipping to change at page 13, line 45
is achieved by relaxing the MUST requirement for having the Home is achieved by relaxing the MUST requirement for having the Home
Address Option presence in Destination Options header and by Address Option presence in Destination Options header and by
introducing a new flag in the Binding Update message. The local introducing a new flag in the Binding Update message. The local
mobility anchor as a traditional IPSec peer can use the SPI in the mobility anchor as a traditional IPSec peer can use the SPI in the
IPSec header [RFC-4306] of the received packet for locating the IPSec header [RFC-4306] of the received packet for locating the
correct security association and for processing the Proxy Binding correct security association and for processing the Proxy Binding
Update message in the context of the Proxy Mobile IPv6 scheme. Update message in the context of the Proxy Mobile IPv6 scheme.
For protocol simplicity, the current specification supports the Per- For protocol simplicity, the current specification supports the Per-
MN-Prefix addressing model. In this addressing model, each mobile MN-Prefix addressing model. In this addressing model, each mobile
node is allocated an exclusively unique home network prefix and the node is allocated an exclusively unique home network prefix. The
prefix is not hosted on the home link. The local mobility anchor in local mobility anchor in this model is just a topological anchor
this addressing model is just a topological anchor point and the point for that prefix and the prefix is physically hosted on the
prefix is physically hosted on the access link where the mobile node access link where the mobile node is attached. The local mobility
is attached. The local mobility anchor is not required to perform anchor is not required to perform any proxy ND operations [RFC-2461]
any proxy ND operations [RFC-2461] for defending the mobile node's for defending the mobile node's home address on the home link.
home address, MN-HoA, on the home link. However, the local mobility However, the local mobility anchor is required to manage the binding
anchor is required to manage the binding cache entry of the mobile cache entry of the mobile node for managing the mobility session and
node for managing the mobility session and also the routing state for also the routing state for creating a proper route path for traffic
creating a proper route path for traffic to/from the mobile node. to/from the mobile node.
5.1. Extensions to Binding Cache Conceptual Data Structure 5.1. Extensions to Binding Cache Conceptual Data Structure
The local mobility anchor maintains a Binding Cache entry for each The local mobility anchor maintains a Binding Cache entry for each
currently registered mobile node. Binding Cache is a conceptual data currently registered mobile node. Binding Cache is a conceptual data
structure, described in Section 9.1 of [RFC3775]. For supporting structure, described in Section 9.1 of [RFC-3775]. For supporting
this specification, the conceptual Binding Cache entry needs to be this specification, the conceptual Binding Cache entry needs to be
extended with the following new fields. extended with the following additional fields.
o A flag indicating whether or not this Binding Cache entry is o A flag indicating whether or not this Binding Cache entry is
created due to a proxy registration. This flag is enabled for created due to a proxy registration. This flag is enabled for
Binding Cache entries that are proxy registrations and is turned Binding Cache entries that are proxy registrations and is turned
off for all other entries that are direct registrations from the off for all other entries that are direct registrations from the
mobile node. mobile node.
o A flag indicating if IPv6 HoA mobility is accepted. If this flag
is set, the relevant IPv6 HoA fields in this data structure have
to be set to the configured values. If this flag.
o The identifier of the mobile node, MN-Identifier. This MN- o The identifier of the mobile node, MN-Identifier. This MN-
Identifier is obtained from the NAI Option present in the Proxy Identifier is obtained from the NAI Option present in the Proxy
Binding Update request [RFC-4285]. Binding Update request [RFC-4285].
o A flag indicating whether or not the Binding Cache entry has a o A flag indicating whether or not the Binding Cache entry has a
home address that is on virtual interface. This flag is enabled, home address that is on virtual interface. This flag is enabled,
if the home prefix of the mobile is configured on a virtual if the home prefix of the mobile node is configured on a virtual
interface. When the configured home prefix of a mobile is on a interface. When the configured home prefix of a mobile is on a
virtual interface, the home agent is not required to function as a virtual interface, the home agent is not required to function as a
Neighbor Discovery proxy for the mobile node. Neighbor Discovery proxy for the mobile node.
o The IPv6 home network prefix of the mobile node. o The IPv6 home network prefix of the mobile node.
o The IPv6 home network prefix length of the mobile node. o The IPv6 home network prefix length of the mobile node.
o The interface id of the tunnel between the local mobility anchor o The interface id of the bi-directional tunnel between the local
and the mobile access gateway used for sending and receiving the mobility anchor and the mobile access gateway used for sending and
mobile node's traffic. receiving the mobile node's traffic.
o Tentative binding cache entry with all the above fields. This
entry is populated upon tentatively accepting a proxy binding
update request for a mobile node whose direct registration still
exists, i.e. the mobile has not deregistered and it received a
proxy binding update request.
5.2. Bi-Directional Tunnel Management 5.2. Bi-Directional Tunnel Management
The bi-directional tunnel between the local mobility anchor and the The bi-directional tunnel between the local mobility anchor and the
mobile access gateway is used for routing the traffic to and from the mobile access gateway is used for routing the traffic to and from the
mobile node. The tunnel hides the topology and enables a mobile node mobile node. The tunnel hides the topology and enables a mobile node
to use an IP address that is topologically anchored at the local to use an IP address that is topologically anchored at the local
mobility anchor, from any attached access link in that proxy mobile mobility anchor, from any attached access link in that proxy mobile
IPv6 domain. The base Mobile IPv6 specification [RFC-3775], does use IPv6 domain. The base Mobile IPv6 specification [RFC-3775], does use
the tunneling scheme for routing traffic to and from the mobile that the tunneling scheme for routing traffic to and from the mobile that
is using its home address. However, there are subtle differences in is using its home address. However, there are subtle differences in
the way Proxy Mobile IPv6 uses the tunneling scheme. the way Proxy Mobile IPv6 uses the tunneling scheme.
As in Mobile IPv4 [RFC-3344], the tunnel between the local mobility As in Mobile IPv4 [RFC-3344], the tunnel between the local mobility
anchor and the mobile access gateway is typically a shared tunnel and anchor and the mobile access gateway is typically a shared tunnel and
can be used for routing traffic streams for different mobile nodes can be used for routing traffic streams for different mobile nodes
attached to the same mobile access gateway. This specification attached to the same mobile access gateway. This specification
extends that 1:1 relation between a tunnel and a binding cache entry extends that 1:1 relation between a tunnel and a binding cache entry
to 1:m relation, reflecting the shared nature of the tunnel. to 1:m relation, reflecting the shared nature of the tunnel.
The tunnel is creating after accepting a Proxy Binding Update request The tunnel is creating after accepting a Proxy Binding Update message
for a mobile node from a mobile access gateway. The created tunnel for a mobile node from a mobile access gateway. The created tunnel
may be shared with other mobile nodes attached to the same mobile may be shared with other mobile nodes attached to the same mobile
access gateway and with the local mobility anchor having a binding access gateway and with the local mobility anchor having a binding
cache entry for those mobile nodes. Some implementations may prefer cache entry for those mobile nodes. Some implementations may prefer
to use static tunnels as supposed to creating and tearing them down to use static tunnels as supposed to creating and tearing them down
on a need basis. on a need basis.
The one end point of the tunnel is the address configured on the The one end point of the tunnel is the address configured on the
interface of the local mobility anchor, LMAA. The other end point of interface of the local mobility anchor, LMAA. The other end point of
the tunnel is the address configured on the interface of the mobile the tunnel is the address configured on the interface of the mobile
access gateway, Proxy-CoA. The tunnel encapsulation mode can be access gateway, Proxy-CoA. The details related to the supported
either IPv6/IPv6, IPv6/IPv4, IPv6/IPv4-UDP, IPv4/IPv6, IPv4/IPv4-UDP, encapsulation modes and transport protocols is covered in detail in
based on the transport mode and the presence of NAT translation Section 6.10.2.
devices on the path.
Implementations typically use a software timer for managing the Implementations typically use a software timer for managing the
tunnel lifetime and a counter for keeping a count of all the mobiles tunnel lifetime and a counter for keeping a count of all the mobiles
that are sharing the tunnel. The timer value will be set to the that are sharing the tunnel. The timer value will be set to the
accepted binding life-time and will be updated after each periodic accepted binding life-time and will be updated after each periodic
registrations for extending the lifetime. If the tunnel is shared registrations for extending the lifetime. If the tunnel is shared
for multiple mobile node's traffic, the tunnel lifetime will be set for multiple mobile node's traffic, the tunnel lifetime will be set
to the highest binding life time across all the binding life time to the highest binding life time across all the binding life time
that is granted for all the mobiles sharing that tunnel. that is granted for all the mobiles sharing that tunnel.
5.3. Routing Considerations 5.3. Routing Considerations
This section describes how the data traffic to/from the mobile node This section describes how the data traffic to/from the mobile node
is handled at the local mobility anchor. The following entries is handled at the local mobility anchor.
explains the routing state that is created for the mobile node home
network prefix.
IPv6 traffic for the Mobile Node's home address:
================================================
MN-HoA::/64 via tunnel0, next-hop Proxy-CoA
tunnel0:
========
Source: LMAA
Destination: Proxy-CoA
Tunnel Transport: IPv6
Tunnel Payload: IPv6
The local mobility anchor functions as a topological anchor point for When a local mobility anchor is serving a mobile node, it MUST
the mobile node's home network prefix. When the local mobility attempt to intercept packets that are sent to any address that is in
anchor receives a data packet from a corresponding node, destined for the mobile node's home network prefix address range. The local
the mobile node's home network prefix, the created routing state will mobility anchor MUST advertise a connected route in to the Routing
enable the packets to be forwarded to the mobile node through the bi- Infrastructure for that mobile node's home network prefix or for an
directional tunnel established between itself and the serving mobile aggregated prefix with a larger scope. This essentially enables
access gateway. routers in the IPv6 network to detect the local mobility anchor as
the last-hop router for that prefix.
If the tunnel between the local mobility anchor and the mobile access When forwarding any packets that have the destination address
gateway is an IPv6 tunnel, i.e. if the registered care-of address is matching the mobile node's home network prefix, the local mobility
the IPv6 Proxy-CoA, any IPv6 packets received from any corresponding anchor MUST encapsulate the packet with the outer IPv6 header, as
node for the mobile node's home network prefix, MN-HNP, will be specified in Generic Packet Tunneling in IPv6 specification [RFC-
encapsulated in an IPv6 packet, IPv6/IPv6 mode, and will be carried 2473]. If the negotiated encapsulation header is either IPv6-over-
as an IPv6 packet. And any IPv4 packets for the mobile node's IPv4- IPv4 or IPv6-over-IPv4-UDP, as specified in the companion document,
MN-HoA, will be encapsulated in an IPv6 packet, IPv4/IPv6 mode, and IPv4 support for Proxy Mobile IP6 [ID-Pv4-PMIP6], the packet must be
will be carried as an IPv6 packet. encapsulated and routed as specified in that specification.
All the reverse tunneled packets that the local mobility anchor All the reverse tunneled packets that the local mobility anchor
receives from the tunnel, after removing the packet encapsulation receives from the tunnel, after removing the outer header MUST be
will get routed to the destination specified in the inner packet routed to the destination specified in the inner packet header.
header. These routed packets will have the source address field set These routed packets will have the source address field set to the
to the mobile node's home address. address from the mobile node's home network prefix.
5.4. Local Mobility Anchor Address Discovery 5.4. Local Mobility Anchor Address Discovery
Dynamic Home Agent Address Discovery, as explained in Section 10.5 of Dynamic Home Agent Address Discovery, as explained in Section 10.5 of
[RFC-3775], allows a mobile node to discover all the home agents on [RFC-3775], allows a mobile node to discover all the home agents on
its home link by sending an ICMP Home Agent Address Discovery Request its home link by sending an ICMP Home Agent Address Discovery Request
message to the Mobile IPv6 Home-Agents anycast address, derived from message to the Mobile IPv6 Home-Agents anycast address, derived from
its home network prefix. its home network prefix.
The Proxy Mobile IPv6 model assumes that the mobile access gateway In Proxy Mobile IPv6, the address of the local mobility anchor
will be able to obtain the address of the local mobility anchor in configured to serve a mobile node can be discovered by the mobility
one or more ways. This MAY be a configured entry in the mobile entities in one or more ways. This MAY be a configured entry in the
node's policy profile, or it MAY be obtained through mechanisms mobile node's policy profile, or it MAY be obtained through
outside the scope of this document. It is important to note that mechanisms outside the scope of this document. It is important to
there is little value in using DHAAD for discovering the local note that there is little value in using DHAAD message in the current
mobility anchor address dynamically. As a mobile moves from one form for discovering the local mobility anchor address dynamically.
mobile access gateway to the another, the serving mobile access As a mobile node moves from one mobile access gateway to the another,
gateway will not predictably be able to locate the serving local the serving mobile access gateway will not predictably be able to
mobility anchor for that mobile that has its binding cache entry for locate the serving local mobility anchor for that mobile that has its
the mobile node. However, if there is only one local mobility anchor binding cache entry for the mobile node. Hence, this specification
configured to serve a mobile node, the mobile access gateway can use does not support Dynamic Home Agent Address Discovery protocol.
Dynamic Home Agent Address Discovery scheme for discovering the
address of the local mobility anchor.
With the currently supported Per-MN-Prefix addressing model, every
mobile node is assigned a unique home network prefix, the local
mobility anchor is a topological anchor point for that prefix and
with the prefix being hosted on the access link attached to the
mobile access gateway. For the discovery scheme to work, the local
mobility anchor MUST be able to receive the ICMP discovery packets
sent to the anycast address derived from the mobile node's home
network prefix.
5.5. Sequence Number and Time-Stamps for Message Ordering 5.5. Sequence Number and Time-Stamps for Message Ordering
Mobile IPv6 [RFC-3775] uses the Sequence Number field in registration Mobile IPv6 [RFC-3775] uses the Sequence Number field in registration
messages as a way to ensure the correct packet ordering. The local messages as a way to ensure the correct packet ordering. The local
mobility anchor and the mobile node are required to manage this mobility anchor and the mobile node are required to manage this
counter over the lifetime of a binding. counter over the lifetime of a binding.
In Proxy Mobile IPv6, the Proxy Binding Update messages that the In Proxy Mobile IPv6, the Proxy Binding Update messages that the
local mobility anchor receives on behalf of a specific mobile node local mobility anchor receives on behalf of a specific mobile node
may not be from the same mobile access gateway as the previously may not be from the same mobile access gateway as the previously
received message. It creates certain ambiguity and the local received message. It creates certain ambiguity and the local
mobility anchor will not be predictably order the messages. This mobility anchor will not be predictably order the messages. This
could lead to the local mobility anchor processing an older message could lead to the local mobility anchor processing an older message
from a mobile access gateway where the mobile node was previously from a mobile access gateway where the mobile node was previously
attached, while ignoring the latest binding update message. attached, while ignoring the latest binding update message.
In the Proxy Mobile IPv6, the ordering of packets has to be In the Proxy Mobile IPv6, the ordering of packets has to be
established accross packets received from multiple senders. The established across packets received from multiple senders. The
sequence number scheme as specified in [RFC-3775] will not be sequence number scheme as specified in [RFC-3775] will not be
sufficient. A global scale, such as a time stamp, can be used to sufficient. A global scale, such as a time stamp, can be used to
ensure the correct ordering of the packets. This document proposes ensure the correct ordering of the packets. This document proposes
the use of a Time Stamp Option, specified in Section 8.4, in all the use of a Time Stamp Option, specified in Section 8.4, in all
Proxy Binding Update messages sent by mobile access gateways. By Proxy Binding Update messages sent by mobile access gateways. By
leveraging the NTP [RFC-1305] service, all the entities in Proxy leveraging the NTP [RFC-1305] service, all the entities in Proxy
Mobile IPv6 domain will be able to synchronize their respective Mobile IPv6 domain will be able to synchronize their respective
clocks. Having a time stamp option in Proxy Binding Update messages clocks. Having a time stamp option in Proxy Binding Update messages
will enable the local mobility anchor to predictably identify the will enable the local mobility anchor to predictably identify the
latest message from a list of messages delivered in an out-of-order latest message from a list of messages delivered in an out-of-order
fashion. fashion.
The Proxy Mobile IP model, defined in this document requires the The Proxy Mobile IPv6 model, defined in this document requires the
Binding Update messages sent by the mobile access gateway to have the Proxy Binding Update messages sent by the mobile access gateway to
time stamp option. The local mobility anchor processing a proxy have the Time Stamp option. The local mobility anchor processing a
registration MUST ignore the sequence number field and SHOULD use the proxy registration MUST ignore the sequence number field and MUST the
value from the Time Stamp option to establish ordering of the value from the Time Stamp option to establish ordering of the
received Binding Update messages. If the local mobility anchor received Binding Update messages. If the local mobility anchor
receives a Binding Update message with an invalid Time Stamp Option, receives a Proxy Binding Update message with an invalid Time Stamp
the Binding Update MUST be rejected and a Binding Acknowledgement Option, the Proxy Binding Update MUST be rejected and a Proxy Binding
MUST be returned in which the Status field is set to 148 (invalid Acknowledgement MUST be returned in which the Status field is set to
time stamp option). 148 (invalid time stamp option).
In the absence of Time Stamp option in the Proxy Binding Update, the In the absence of Time Stamp option in the Proxy Binding Update, the
entities can fall back to Sequence Number scheme for message entities can fall back to Sequence Number scheme for message
ordering, as defined in RFC-3775. However, the specifics on how ordering, as defined in RFC-3775. However, the specifics on how
different mobile access gateways synchronize the sequence number is different mobile access gateways synchronize the sequence number is
outside the scope of this document. outside the scope of this document.
When using the Time Stamp Option, the local mobility anchor or the When using the Time Stamp Option, the local mobility anchor or the
mobile access gateway MUST set the the timestamp field to a 64-bit mobile access gateway MUST set the timestamp field to a 64-bit value
value formatted as specified by the Network Time Protocol [RFC-1305]. formatted as specified by the Network Time Protocol [RFC-1305]. The
The low-order 32 bits of the NTP format represent fractional seconds, low-order 32 bits of the NTP format represent fractional seconds, and
and those bits which are not available from a time source SHOULD be those bits which are not available from a time source SHOULD be
generated from a good source of randomness. generated from a good source of randomness.
5.6. Route Optimizations Considerations 5.6. Route Optimizations Considerations
Mobile IPv6 route optimization, as defined in [RFC-3775], enables a Mobile IPv6 route optimization, as defined in [RFC-3775], enables a
mobile node to communicate with a corresponding node directly using mobile node to communicate with a corresponding node directly using
its care-of address and further the Return Routability procedure its care-of address and further the Return Routability procedure
enables the corresponding node to have reasonable trust that the enables the corresponding node to have reasonable trust that the
mobile node owns both the home address and care-of address. mobile node owns both the home address and care-of address.
In the Proxy Mobile IPv6 model, the mobile is not involved in any In the Proxy Mobile IPv6 model, the mobile is not involved in any
mobility related signaling and also it does not operate in the dual- mobility related signaling and also it does not operate in the dual-
address mode. Hence, the return routability procedure as defined in address mode. Hence, the return routability procedure as defined in
RFC-3775 is not applicable for the proxy model. This document does RFC-3775 is not applicable for the proxy model.
not address the Route Optimization problem and leaves this work item
for future enhancements.
5.7. Mobile Prefix Discovery Considerations 5.7. Mobile Prefix Discovery Considerations
The ICMP Mobile Prefix Advertisement message, described in Section The ICMP Mobile Prefix Advertisement message, described in Section
6.8 and Section 11.4.3 of [RFC-3775], allows a home agent to send a 6.8 and Section 11.4.3 of [RFC-3775], allows a home agent to send a
Mobile Prefix Advertisement to the mobile node. Mobile Prefix Advertisement to the mobile node.
In Proxy Mobile IPv6 deployments, the mobile node's home network In Proxy Mobile IPv6, the mobile node's home network prefix is hosted
prefix is hosted on the access link shared between the mobile access on the access link connected to the mobile access gateway. but
gateway and the mobile node, but topologically anchored on the local topologically anchored on the local mobility anchor. Since, there is
mobility anchor. Since, there is no physical home-link for the no physical home-link for the mobile node's home network prefix on
mobile node's home network prefix on the local mobility anchor and as the local mobility anchor and as the mobile is always on the link
the mobile is always on the link where the prefix is hosted, any where the prefix is hosted, any prefix change messages can just be
prefix change messages can just be advertised by the mobile access advertised by the mobile access gateway on the access link and thus
gateway on the access link and thus there is no applicability of this there is no applicability of this message for Proxy Mobile IPv6.
messaging for Proxy Mobile IPv6. This specification does not support This specification does not use Mobile Prefix Discovery.
Mobile Prefix Discovery.
5.8. Local Mobility Anchor Operational Summary 5.8. Signaling Considerations
o For supporting this scheme, the local mobility anchor MUST satisfy 5.8.1. Initial Proxy Binding Registration
all the requirements listed in Section 8.4 of Mobile IPv6
specification [RFC-3775] with the following considerations.
o For supporting the per-MN-Prefix addressing model as defined in Upon receiving a Proxy Binding Update message from a mobile access
this specification, the local mobility anchor service MUST NOT be gateway on behalf of mobile node, the local mobility anchor MUST
tied to a specific interface. It SHOULD be able to accept Proxy process the request as defined in Section 10, of the base Mobile IPv6
Binding Update requests sent to any of the addresses configured on specification [RFC-3775], with one exception that this request is a
any of its interfaces. proxy request, the sender is not the mobile node and so the message
has to be processed with the considerations explained in this
section.
o The requirement for a home agent to maintain a list of home agents The local mobility anchor MUST apply the required policy checks, as
for a mobile node's home link is not applicable for the local explained in Section 4.0 of this document to verify the sender is a
mobility anchor, when supporting Per-MN-Prefix addressing model as trusted mobile access gateway, authorized to send Proxy Binding
there is no link specific relation between the two. Updates requests on behalf of that mobile nodes, using its own
identity. The local mobility anchor must check the local/remote
policy store to ensure the requesting node is authorized to send
Proxy Binding Update messages.
o After receiving a Proxy Binding Update request from a mobile The local mobility anchor MUST use the MN-Identifier from the NAI
access gateway on behalf of mobile node, the local mobility anchor option of the Proxy Binding Update message for identifying the mobile
MUST process the request as defined in Section 10, of the base node.
Mobile IPv6 specification [RFC-3775], with one exception that this
request is a proxy request, the sender is not the mobile node and
so the message has to be processed with the considerations
explained in this section.
o The local mobility anchor MUST apply the required policy checks, The local mobility anchor MUST ignore the sequence number field in
as explained in Section 4.0 of this document to verify the sender the Proxy Binding Updates requests, if the Time-Stamp Option is
is a a trusted mobile access gateway, authorized to send proxy present in the message. It must also skip all the checks related to
binding updates requests on behalf of that mobile nodes, using its sequence number that are required as per the Mobile IPv6
own identity. The local mobility anchor must check the local/ specification [RFC-3775]. However, the received sequence number MUST
remote policy store to ensure the requesting node is authorized to be copied and returned in the Proxy Binding Acknowledgement message
send proxy binding update requests. sent to the mobile access gateway.
o Upon accepting a proxy binding update request from a mobile access The local mobility anchor before accepting a Proxy Binding Update
request containing the Home Network Prefix Option with a specific
prefix, MUST ensure the prefix is owned by the local mobility anchor
and further the mobile node is authorized to use that prefix. If the
Home Network Prefix Option has the value 0::/0, the local mobility
anchor MUST allocate a prefix for the mobile node and send a Proxy
Binding Acknowledgement message with the Home Network Prefix Option
containing the allocated value. The specific details on how the
local mobility anchor allocates the home network prefix is outside
the scope of this document.
Upon accepting a Proxy Binding Update request from a mobile access
gateway, the local mobility anchor must check if there exists a gateway, the local mobility anchor must check if there exists a
binding cache entry for that mobile node, identified using the MN- binding cache entry for that mobile node, identified using the MN-
Identifier, that was created due to a direct registration from the Identifier, that was created due to a direct registration from the
mobile node. If there exists a binding cache entry with the proxy mobile node. If there exists a binding cache entry with the proxy
registration flag turned off, the local mobility anchor MUST NOT registration flag turned off, the local mobility anchor MUST NOT
modify that binding state, instead it must create a tentative modify that binding state, instead it must create a tentative binding
binding cache entry and update the tentative binding cache entry cache entry and update the tentative binding cache entry fields of
fields of that binding cache entry. that binding cache entry.
o Upon receiving a Binding Update request from a mobile node with Upon receiving a Binding Update request from a mobile node with
lifetime value set to 0, from a tunnel between itself and a lifetime value set to 0, from a tunnel between itself and a trusted
trusted mobile access gateway, the local mobility anchor upon mobile access gateway, the local mobility anchor upon accepting that
accepting that de-registration message, MUST forward the Binding de-registration message, MUST forward the Binding Acknowledgement
Acknowledgement message in the tunnel from where it received the message in the tunnel from where it received the Binding Update
Binding Update request. It must also replace the binding cache request. It must also replace the binding cache entry with the
entry with the tentative binding cache entry and enable routing tentative binding cache entry and enable routing for the mobile
for the mobile node's home prefix through the proxy mobile IPv6 node's home network prefix through the proxy mobile IPv6 tunnel.
tunnel.
o The local mobility anchor MUST use the MN-Identifier present in Upon accepting this Proxy Binding Update message, the local mobility
the NAI option of the Proxy Binding Update request for identifying anchor must create a Binding Cache entry and must set up a tunnel to
the mobile node. the mobile access gateway serving the mobile node. This bi-
directional tunnel between the local mobility anchor and the mobile
access gateway is used for routing the mobile node's traffic.
o The local mobility anchor MUST ensure the prefix presented in the The Proxy Binding Acknowledgment message must be constructed as shown
Home Network Prefix option of the received Proxy Binding Update below.
request is owned by itself and further the mobile node identified
by MN-Identifier is authorized to use this prefix.
o The local mobility anchor MUST ignore the sequence number field in IPv6 header (src=LMAA, dst=Proxy-CoA)
the Proxy Binding Updates requests, if the Time-Stamp Option is Mobility header
present in the message. It must also skip all the checks related -BA /*P flag is set*/
to sequence number as suggested in the Mobile IPv6 specification Mobility Options
[RFC-3775]. However, the received sequence number MUST be copied - Home Network Prefix Option
and returned in the Proxy Binding Acknowledgement sent to the - TimeStamp Option (optional)
mobile access gateway. - NAI Option
o Upon accepting this request, the local mobility anchor must create Proxy Binding Acknowledgment message contents
a Binding Cache entry with the home address from the Home Network
Prefix Option in the Binding Update and must set up a tunnel to 5.8.2. Extending the binding lifetime
the proxy mobile agent serving the mobile node. This bi-
directional tunnel between the local mobility anchor and the Upon accepting the Proxy Binding Update request for extending the
mobile access gateway is used for routing the mobile traffic. lifetime of a currently active binding, the local mobility anchor
MUST update the lifetime for that binding and send a Proxy Binding
Acknowledgment message to the mobile access gateway. The Proxy
Binding Acknowledgment message MUST be constructed as specified in
Section 5.8.1.
5.8.3. De-registration of the binding
Upon accepting the Proxy Binding Update request sent with the
lifetime value of zero, the local mobility anchor MUST delete the
binding from its Binding Cache and MUST send a Proxy Binding
Acknowledgment message to the mobile access gateway. The message
MUST be constructed as specified in Section 6.9.1.
The local mobility anchor MUST also remove the prefix route over the
tunnel for that mobile node's home network prefix.
5.9. Local Mobility Anchor Operational Summary
o For supporting this scheme, the local mobility anchor MUST satisfy
all the requirements listed in Section 8.4 of Mobile IPv6
specification [RFC-3775] with the following considerations.
o For supporting the per-MN-Prefix addressing model as defined in
this specification, the local mobility anchor service MUST NOT be
tied to a specific interface. It SHOULD be able to accept Proxy
Binding Update requests sent to any of the addresses configured on
any of its interfaces.
o The requirement for a home agent to maintain a list of home agents
for a mobile node's home link is not applicable for the local
mobility anchor, when supporting Per-MN-Prefix addressing model.
o The local mobility anchors SHOULD drop all HoTI messages received o The local mobility anchors SHOULD drop all HoTI messages received
for a home address that has corresponding Binding Cache entry with for a home address that has corresponding Binding Cache entry with
the proxy registration flag set. the proxy registration flag set.
o The local mobility anchor must handle the mobile node's data o The local mobility anchor must handle the mobile node's data
traffic as explained in the Routing Considerations section of this traffic as explained in the Routing Considerations section of this
document. document.
6. Mobile Access Gateway Operation 6. Mobile Access Gateway Operation
skipping to change at page 22, line 5 skipping to change at page 21, line 24
node. node.
From the perspective of the local mobility anchor, the mobile access From the perspective of the local mobility anchor, the mobile access
gateway is a special element in the network that sends Mobile IPv6 gateway is a special element in the network that sends Mobile IPv6
signaling messages on behalf of a mobile node, but using its own signaling messages on behalf of a mobile node, but using its own
identity. It is the entity that binds the mobile node's home address identity. It is the entity that binds the mobile node's home address
to an address on its own access interface. to an address on its own access interface.
The mobile access gateway has the following functional roles. The mobile access gateway has the following functional roles.
o It is responsible for detecting the mobile node's attachment or o Responsible for detecting the mobile node's attachment or
detachment on the connected access link and for initiating the detachment on the connected access link and for initiating the
mobility signaling to the mobile node's local mobility anchor. mobility signaling with the mobile node's local mobility anchor.
o Emulation of the mobile node's home link on the access link. o Emulation of the mobile node's home link on the access link.
o It is responsible for setting up the data path for enabling the o Registering the binding state at the mobile node's local mobility
mobile node to use its home address for communication from the anchor.
access link.
This Proxy Mobile IPv6 scheme is independent of the underlying access o Responsible for setting up the data path for enabling the mobile
technology or the link model. The interface between the mobile node node to use an address from its home network prefix and use it
and the mobile access gateway can be either: from the access link.
o Point-to-Point Link The mobile access gateway is a function that typically runs on an
access router. However, implementations MAY choose to split this
function and run it across multiple systems. The specifics on how
that is achieved is beyond the scope of this document.
o Shared Link 6.1. Supported Access Link Types
This specification does not support split links. This specification supports only point-to-point access link types and
thus it assumes that the link between the mobile node and the mobile
access gateway is a dedicated link and that the mobile node and the
mobile access gateway are the only two nodes present on that link.
The assumed properties for the point-to-point link type are just as
assumed by the Neighbor Discovery specification [RFC-2461] for that
link type. The link is assumed to have multicast capability and the
interfaces connecting to the link can be configured with a link-local
address.
6.1. Address Configuration Models Support for shared links or other link types is left for the future
work.
Currently, this specification only supports Per-MN-Prefix model In 6.2. Supported Home Network Prefix Models
the Per-MN-Prefix model, there is a unique home network prefix
assigned for each mobile node and that prefix is hosted on the access This specification supports Per-MN-Prefix model and does not support
link. Conceptually, the prefix just follows the mobile node as it Shared-Prefix model. As per the Per-MN-Prefix model, there will be a
moves within the proxy mobile IPv6 domain. In this addressing model, unique home network prefix assigned for each mobile node and no other
based on the administrative policy, the mobile node can use either host shares an address from that prefix. The prefix is always hosted
Stateless Address Autoconfiguration or Statefull Address on the access link where the mobile node is anchored. Conceptually,
Configuration using DHCP for obtaining the IPv6 address configuration the prefix follows the mobile node as it moves within the proxy
for its interface on the access link. Further, the mobile node can mobile IPv6 domain. However, from the routing perspective, the home
also generate interface identifiers with privacy considerations, as network prefix is topologically anchored on the local mobility
specified in Privacy Extensions specification [RFC-3041] and as per anchor.
CGA specification [RFC-3042]. For IPv4 home address configuration,
the mobile node can obtain the address configuration using DHCP or 6.3. Supported Address Configuration Models
optionally by using IPCP. In addition to this, Other address
configuration mechanisms specific to the access link between the A mobile node in the proxy mobile IPv6 domain can configure one or
mobile node and the mobile access gateway may also be used by the more IPv6 addresses on its interface using Stateless or Stateful
address autoconfiguration procedures. The Router Advertisement
messages sent on the access link, specify the address configuration
methods permitted on that access link for that mobile node. The
exact semantics of the flags that are enabled, the options that are
carried in these advertisement messages is as per the Neighbor
Discovery specification [RFC-2461]. However, the advertised flags
with respect the address configuration will be consistent for a
mobile node, on any of the access links in that proxy mobile IPv6
domain. Typically, these configuration settings will be based on the
domain wide policy or based on a policy specific to each mobile node.
This specification requires that all the mobile access gateways in a
given proxy mobile IPv6 domain MUST ensure that the permitted address
configuration procedures or the address configuration parameters that
are sent in the Router Advertisements are consistent for a mobile
node when attached to on any of the access links in the proxy mobile
IPv6 domain.
When stateless address autoconfiguration is supported on the link,
the mobile node can generate one or more IPv6 addresses by combining
the network prefix advertised on the access link with an interface
identifier, using the techniques described in Stateless
Autoconfiguration specification [RFC-2462] or in Privacy extension
specification [RFC-3041].
When stateful address autoconfiguration is supported on the link, the
mobile node obtains the address configuration from the DHCPv6 server
using DHCPv6 client protocol, as specified in DHCPv6 specification
[RFC-3315].
In addition to this, other address configuration mechanisms specific
to the access link between the mobile node and the mobile access
gateway may also be used for pushing the address configuration to the
mobile node. mobile node.
The configured administrative policy for the mobile dictates the type 6.4. Access Authentication & Mobile Node Identification
of addressing model that is supported for a mobile on the access
link. The mobile access gateway on the access router will control
this by setting the relevant flags in the Router Advertisement that
it sends on the access link.
6.2. Conceptual Data Structures When a mobile node attaches to an access link connected to the mobile
access gateway, the deployed access security protocols on that link
will ensure that the network-based mobility management service is
offered only after authenticating and authorizing the mobile node for
that service. The exact specifics on how this is achieved or the
interactions between the mobile access gateway and the access
security service is outside the scope of this document. This
specification goes with the stated assumption of having an
established trust and a secured communication link between the mobile
node and mobile access gateway, before the protocol operation begins.
The specification also requires that the mobile access gateway MUST
be able to identify the mobile node by its MN-Identifier and it must
also be able to associate this identity to the sender of any IPv4 or
IPv6 packets on the access link. The mobile access gateway MUST also
be able to obtain the mobile node's policy profile using the MN-
Identifier.
Every mobile access gateway maintains a Binding Update List for each 6.5. Mobile Node's Policy Profile
currently attached mobile node. The Binding Update List is a
A mobile node's policy profile contains the essential operational
parameters that are required by the network entities for managing the
mobile node's mobility service. These policy profiles are stored in
a local or a remote policy store, the mobile access gateway and the
local mobility anchor MUST be able to obtain a mobile node's policy
profile using its MN-Identifier. The policy profile may also be
handed over to a serving mobile access gateway as part of a context
transfer procedure during a handoff. The exact details on how this
achieved is outside the scope of this document. However, this
specification requires that a mobile access gateway serving a mobile
node MUST have access to its policy profile.
The following are the mandatory fields of the policy profile:
o The mobile node's identifier (MN-Identifier)
o The IPv6 address of the local mobility anchor (LMAA)
o Supported address configuration procedures on the link (Stateful,
Stateless or both)
The following are the optional fields of the policy profile:
o The mobile node's IPv6 home network prefix (MN-HoA)
o The mobile node's IPv6 home network prefix length
6.6. Conceptual Data Structures
Every mobile access gateway MUST maintain a Binding Update List for
each currently attached mobile node. The Binding Update List is a
conceptual data structure, described in Section 11.1 of Mobile IPv6 conceptual data structure, described in Section 11.1 of Mobile IPv6
base specification [RFC-3775]. For supporting this specification, base specification [RFC-3775]. For supporting this specification,
the conceptual Binding Update List data structure must be extended the conceptual Binding Update List data structure must be extended
with the following new additional fields. with the following new additional fields.
o The Identifier of the mobile node, MN-Identifier. The format of o The Identifier of the mobile node, MN-Identifier.
the MN-Identifier is specific to the access technology. This MN
identifier is obtained as part of the Access Authentication
procedure and is used for downloading the mobile node's profile
from the policy store.
o The physical address or the MAC address of the mobile node's o The MAC address of the mobile node's connected interface.
connected interface.
o The IPv6 home network prefix of the mobile node. o The IPv6 home network prefix of the mobile node.
o The IPv6 home network prefix length of the mobile node. o The IPv6 home network prefix length of the mobile node.
o The link-local address of the mobile node on the link. This o The interface identifier of the point-to-point link to the mobile
address MAY be learnt from the source address of the Router node.
Solicitation message received from the mobile node.
o The tunnel identifier of the tunnel between the mobile access o The interface identifier of the tunnel between the mobile access
gateway and the local mobility anchor used for reverse tunneling gateway and the mobile node's local mobility anchor.
the mobile node's traffic. On a given implementation, if a tunnel
appears like a virtual interface, that applies the proper
encapsulation on every packet that is routed through that
interface, then the interface identifier is stored in the binding
update list. entry.
6.3. Access Authentication 6.7. Home Network Emulation
When a mobile node attaches to the access link connected to the One of the key functions of a mobile access gateway is to emulate the
mobile access gateway, the deployed access security protocols will mobile node's home network prefix on the access link. It must
ensure that only authorized mobile nodes will be able to access the ensure, the mobile node believes it is still connected to its home
link and further the mobile access gateway will be able to identify link or on the link where it obtained its address configuration after
the mobile node by its MN-Identifier and optionally will be able to it moved into that proxy mobile IPv6 domain.
detect the mobile node's attachment or detachment to the link. The
exact specifics on how this is achieved is outside the scope of this
document. This document goes with the stated assumption of having an
established trust between the mobile node and mobile access gateway
on the access link before the protocol operation begins. The mobile
access gateway will be able to use the mobile node's MN-Identity and
will be obtain its policy profile from the network policy store or
from the local policy store.
6.4. Home Network Emulation After detecting new mobile node on its access link and after a
successful access authentication and authorization of the mobile node
for network-based mobility service, the mobile access gateway MUST to
emulate the mobile node's home link by sending the Router
Advertisements with the mobile node's home network prefix as the
hosted on-link prefix. The Router Advertisement MUST be sent in
response to a Router Solicitation message that it received from the
mobile node. The Router Advertisement messages MAY also be sent
periodically, based on the interface configuration on the mobile
access gateway.
One of the key functions of the mobile access gateway is to emulate For emulating the mobile node's home link on the access link, the
the mobile node's home network on the access link. It has to ensure, mobile access gateway must know the home network prefix of the mobile
the mobile node believes it is connected to its home link or the link node for constructing the Router Advertisement. Typically and as a
where it obtained its address configuration after it moved into that default method, the mobile access gateway learns the mobile node's
proxy mobile IPv6 domain. After the access authentication is home network prefix information from the Proxy Binding
complete, the mobile access gateway will have access to the mobile Acknowledgement message, it received in response to the Proxy Binding
node's profile, obtained from querying a local/network policy store Update message that it sent to the mobile node's local mobility
or provided to it as part of some context transfer procedure. After anchor for that mobile node.
this point, the mobile access gateway will have enough information to
emulate the mobile node's home link. It must send the Router However, it is also possible, the mobile node's home network prefix
Advertisement messages advertising the mobile node's home network information may be statically configured in the mobile node's policy
prefix and other parameters. profile or it may be handed over to the mobile access gateway as part
of a context transfer procedure. If the mobile access gateway can
predictably know the mobile node's home network prefix information,
it MAY choose to send the Router Advertisement prior to receiving the
Proxy Binding Acknowledgement message from the local mobility anchor.
However, in the event, the local mobility anchor rejects the Proxy
Binding Update message, or if the prefix that is received from the
local mobility anchor for that mobile node is a different prefix than
what the mobile access gateway previously advertised, the mobile
access gateway MUST withdraw the prefix by sending a Router
Advertisement message with zero lifetime for the prior advertised
prefix.
If the access link connecting the mobile access gateway and the If the access link connecting the mobile access gateway and the
mobile node is a point-to-point link, the Router Advertisements mobile node is a point-to-point link, the Router Advertisements
advertising a specific home network prefix is received only by the advertising a specific home network prefix is received only by the
respective mobile node and hence there is clearly a unique link for respective mobile node and hence there is clearly a unique link for
each mobile node that is attached to that mobile access gateway. each mobile node that is attached to that mobile access gateway.
If the access link connecting the mobile access gateway and the 6.7.1. Home Network Prefix Renumbering
mobile node is a shared-link, the mobile access gateway MUST ensure
that each of the mobile node that is attached to that link receives
Router Advertisements with its respective home network prefix as the
on-link prefix. For this to happen, the mobile access gateway MUST
unicast the Router Advertisement to the mobile node. The destination
field of the link-layer header in the Router Advertisement MUST be
the mobile's node's interface physical/MAC address and however, the
destination field in the IPv6 header set to the all-nodes-multicast
address.
6.5. Link-Local and Global Address Uniqueness If the mobile node's home network prefix gets renumbered or becomes
invalid during the middle of a mobility session, the mobile access
gateway MUST withdraw the prefix by sending a Router Advertisement on
the access link with zero prefix lifetime for the mobile node's home
network prefix. Also, the local mobility anchor and the mobile
access gateway MUST delete the routing state for that prefix.
However, the specific details on how the local mobility anchor
notifies the mobile access gateway is outside the scope of this
document.
A mobile node in a proxy mobile IPv6 domain, as it moves from one 6.8. Link-Local and Global Address Uniqueness
access link to the other, will continue to detect its home network
and hence the issue of link-local address uniqueness arises. The
link-local that the mobile node attempts to use on the new link must
be unique.
On a point-to-point link, such as in a PPP session, when the mobile A mobile node in the proxy mobile IPv6 domain, as it moves from one
node tries to establish a PPP session [RFC-1661] with the mobile mobile access gateway to the other, it will continue to detect its
home network and thus making the node believe it is still on the same
link. Every time the mobile node attaches to a new link, the event
related to the interface state change, will trigger the mobile node
to perform DAD operation on the link-local and global addresses.
However, if the node is DNAv6 enabled, as specified in [ID-DNAV6], it
may not detect the link change due to DNAv6 optimizations and hence
it will not trigger the duplicate address detection (DAD) procedure
for establishing the link-local address uniqueness on that new link.
Further, if the mobile node uses an interface identifier that is not
based on EUI-64 identifier, such as specified in IPv6 Stateless
Autoconfiguration specification [RFC-2462], there is a possibility,
with the odds of 1 to billion, of a link-local address collision
between the two neighbors, the mobile node and the mobile access
gateway.
One of the workarounds for this issue is to set the DNAv6
configuration parameter, DNASameLinkDADFlag to TRUE and that will
force the mobile node to redo DAD operation every time the interface
comes up, even when DNAv6 does detect a link change .
However, this issues will not impact point-to-point links based on
PPP session. Each time the mobile node moves and attaches to a new
mobile access gateway, either the PPP session [RFC-1661] is
reestablished or the PPP session may be moved as part of context
transfer procedures between the old and the new mobile access
gateway.
When the mobile node tries to establish a PPP session with the mobile
access gateway, the PPP goes through the Network layer Protocol phase access gateway, the PPP goes through the Network layer Protocol phase
and the IPv6 Control Protocol, IPCP6 [RFC-2472] gets triggered. Both and the IPv6 Control Protocol, IPCP6 [RFC-2472] gets triggered. Both
the PPP peers negotiate a unique identifier using Interface- the PPP peers negotiate a unique identifier using Interface-
Identifier option in IPV6CP and the negotiated identifier is used for Identifier option in IPV6CP and the negotiated identifier is used for
generating a unique link-local address on that link. Now, if the generating a unique link-local address on that link. Now, if the
mobile node moves to a new access router, the PPP session gets torn mobile node moves to a new mobile access gateway, the PPP session
down and new PPP session with the new mobile access gateway will be gets torn down with the old mobile access gateway and a new PPP
established and the mobile obtains a new link-local address. Now, session gets established with the new mobile access gateway, and the
even if the mobile is DNAv6 capable, as specified in the DNAv6 mobile node obtains a new link-local address. So, even if the mobile
specification [draft-ietf-dna-protocol-03], the mobile node always node is DNAv6 capable, the mobile node always configures a new link-
configures a new link-local address when ever it moves to a new link. local address when ever it moves to a new link.
However, if the link between the mobile node and the mobile access If the PPP session state is moved to the new mobile access gateway,
gateway is a shared link and if a DNAv6 capable mobile node moves as part of context transfer procedures that are in place, there will
from one access link to the other, the mobile node may not detect a not be any change to the interface identifiers of the two nodes on
link change due to the optimizations from DNAv6 and hence there is a that point-to-point change. The whole link is moved to the new
possibility of the link-local address collision on the connected mobile access gateway and there will not be any need for establishing
access link, One of the work around for this issue to the set link-local address uniqueness on that link.
following flag on the mobile node, DNASameLinkDADFlag to TRUE and
that will force the mobile node to redo DAD operation even when DNAv6
detects no link change.
The global address or the MN-HoA uniqueness is assured as the This issue is not relevant to the mobile node's global address.
uniqueness is established by the local mobility anchor before Since, there is a unique home network prefix for each mobile node,
accepting a proxy binding update for a mobile node. This is further the uniqueness for the mobile node's global address is ensured on the
assured with the currently supported per-mn-prefix model, as there access link.
are two mobile nodes that share the same home network prefix.
Further, if the address configuration is based on statefull address
configuration using DHCP, the DHCP server will ensure the uniqueness.
6.6. Tunnel Management 6.9. Signaling Considerations
In the traditional Mobile IPv6 model, there is a separate tunnel from 6.9.1. Initial Attachment and binding registration
the local mobility anchor to every mobile node that has a binding
cache entry. The one end-point of these tunnels is the respective
mobile node's care-of address and that is unique to that mobile node.
In the case of Proxy Mobile IPv6, the care-of address or the tunnel
end-point is the address of the mobile access gateway and there could
be multiple mobile nodes attached to the same mobile access gateway
and hence the tunnel is a shared tunnel serving multiple mobile
nodes. This is identical to the Mobile IPv4 model [RFC-3344], where
a tunnel between the foreign agent and the home agent is shared by
many visiting mobile nodes and hence the tunnel management needs to
be on a global basis and not be dependent on a specific mobile node's
binding.
The life of the Proxy Mobile IPv6 tunnel should not be based on a After detecting a new mobile node on its access link after a
single binding cache entry. The tunnel may get created as part of successful access authentication and authorization, the mobile access
creating a mobility state for a mobile node and later the same tunnel gateway MUST send a Proxy Binding Update message to the mobile node's
may be associated with other mobile nodes. So, the tearing down local mobility anchor.
logic of the tunnel must be based on the number of visitors over that
tunnel. Implementations are free to pre-establish tunnels between
every local mobility anchor and every mobile access gateway in a
proxy mobile IPv6 domain and with out having to create and destroy
the tunnels on a need basis.
6.7. Routing Considerations The Proxy Binding Update message must be constructed as shown below.
This section describes how the data traffic to/from the mobile node IPv6 header (src=Proxy-CoA, dst=LMAA)
is handled at the mobile access gateway. The following entries Mobility header
explains the routing state for the mobile node on the mobile access -BU /*P flag is set*/
gateway. Mobility Options
- Home Network Prefix Option*
- TimeStamp Option (optional)
- NAI Option
Mobile Node's IPv6 traffic: *Home Network Prefix option may contain 0::/0 or a specific prefix.
===========================
For all traffic from the source address MN-HoA to destination 0::/0
route via tunnel0, next-hop LMAA.
MN-HoA::/64 is reachable via the directly connected interface. Proxy Binding Update message contents
tunnel0: The Proxy Binding Update message that the mobile access gateway sends
======== to the mobile node's local mobility anchor MUST have the NAI option,
Source: Proxy-CoA identifying the mobile node, the Home Network Prefix option and
Destination: LMAA optionally the Time Stamp option SHOULD be present. The Time Stamp
Tunnel Payload: IPv6 option is not required if the mobile access gateway can send a valid
Tunnel Transport: IPv6 sequence number that matches the sequence number maintained by the
local mobility anchor for that mobile node in its binding cache
entry. The message MUST be protected by using IPsec ESP, using the
security association existing between the local mobility anchor and
the mobile access gateway, created either dynamically or statically.
When the mobile access gateway receives any packets from the mobile If the mobile access gateway learns the mobile node's home network
node to any destination, the packet will be forwarded to the local prefix either from its policy store or from other means, the mobile
mobility anchor through the bi-directional tunnel established between access gateway MAY choose to specify the same in the Home Network
itself and the mobile's local mobility anchor. However, the packets Prefix option for requesting the local mobility anchor to register
that are sent with link-local source address are not forwarded. that prefix. If the specified value is 0::/0, then the local
mobility anchor will allocate a prefix to the mobile node.
If the tunnel between the mobile access gateway and local mobility After receiving a Proxy Binding Acknowledgment with the status code
anchor is an IPv6 tunnel i.e. if the registered care-of address is an indicating the acceptance of the Proxy Binding Update, the mobile
IPv6 Proxy-CoA, any IPv6 packet from the mobile node with the source access gateway MUST setup a tunnel to the mobile node's local
MN-HoA, will be encapsulated in an IPv6 packet, IPv6/IPv6 mode and mobility anchor, as explained in section 6.10. The mobile access
will be carried as an IPv6 packet. And any IPv4 packet from the gateway MUST also add a policy route for tunneling all the packets
mobile node with the source IPv4 Mobile-HoA, will be encapsulated in that it receives from the mobile node to its local mobility anchor.
an IPv6 packet, IPv4/IPv6 mode, and will be carried as an IPv6
packet.
All the packets that the mobile access gateway receives from the If the local mobility anchor rejects the Proxy Binding Update
tunnel, after removing the tunnel encapsulation, will forward it to message, the mobile access gateways MUST NOT advertise the mobile
the mobile node on the connected interface. node's home prefix on the access link and there by denying mobility
service to the mobile node.
6.8. Interaction with DHCP Relay Agent 6.9.2. Extending the binding lifetime
If Statefull Address Configuration using DHCP is supported on the For extending the lifetime of a currently existing binding at the
link on which the mobile node is attached, the DHCP relay agent [RFC- local mobility, the mobile access gateway MUST send a Proxy Binding
3315] needs to be configured on the access router. When the mobile Update message with a specific lifetime. The message MUST be
node sends a DHCPv6 Request message, the relay agent function on the constructed as specified in Section 6.9.1.
access router must set the link-address field in the DHCPv6 message
6.9.3. De-registration of the binding
At any point, the mobile access gateway detects that the mobile node
has moved away from its access link, it MUST send a Proxy Binding
Update message to the mobile node's local mobility anchor with the
lifetime value set to zero. The message MUST be constructed as
specified in Section 6.9.1.
The mobile access gateway MUST also remove the default route over the
tunnel for that mobile node and delete the Binding Update List for
that mobile node, either upon receiving an Proxy Binding
Acknowledgment message from the local mobility anchor or after a
certain timeout waiting for the acknowledgment message.
6.10. Routing Considerations
This section describes how the mobile access gateway handles the
traffic to/from the mobile node that is attached to one of its access
interface.
Proxy-CoA LMAA
| |
+--+ +---+ +---+ +--+
|MN|----------|MAG|======================|LMA|----------|CN|
+--+ +---+ +---+ +--+
IPv6 Tunnel
6.10.1. Transport Network
The transport network between the local mobility anchor and the
mobile access can be either an IPv6 or IPv4 network. However, this
specification only deals with the scenario where the transport
network between the mobility entities is IPv6-only and requires
reachability between the local mobility anchor and the mobile access
gateway over IPv6 transport. Just as in Mobile IPv6 specification
[RFC-3775], the negotiated tunnel transport between the local
mobility anchor and the mobile access gateway is IPv6, by default.
The companion document, IPv4 support for Proxy Mobile IPv6 [IPv4-
PMIP6-SPEC] specifies the required extensions for negotiating IPv4
tunneling mechanism and a specific encapsulation mode for supporting
this protocol operation over IPv4 transport network.
6.10.2. Tunneling & Encapsulation Modes
The IPv6 address that a mobile node uses from its home network prefix
is topologically anchored at the local mobility anchor. For a mobile
node to use this address from an access network attached to a mobile
access gateway, proper tunneling techniques have to be in place.
Tunneling hides the network topology and allows the mobile node's
IPv6 datagrams to be encapsulated as a payload of another IPv6 packet
and be routed between the local mobility anchor and the mobile access
gateway. The Mobile IPv6 base specification [RFC-3775] defines the
use of IPv6-over-IPv6 tunneling, between the home agent and the
mobile node and this specification extends the use of the same
tunneling mechanism between the local mobility anchor and the mobile
access gateway.
On most operating systems, tunnels are implemented as a virtual
point-to-point interface. The source and the destination address of
the two end points of this virtual interface along with the
encapsulation mode are specified for this virtual interface. Any
packet that is routed over this interface, get encapsulated with the
outer header and the addresses as specified for that point to point
tunnel interface. For creating a point to point tunnel to any local
mobility anchor, the mobile access gateway may implement a tunnel
interface with the source address field set to its Proxy-CoA address
and the destination address field set to the LMA address.
The following are the supported packet encapsulation modes that can
be used by the mobile access gateway and the local mobility anchor
for routing mobile node's IPv6 datagrams.
o IPv6-In-IPv6 - IPv6 datagram encapsulated in an IPv6 packet. This
mechanism is defined in the Generic Packet Tunneling for IPv6
specification [RFC-2473].
o IPv6-In-IPv4 - IPv6 datagram encapsulation in an IPv4 packet. The
details related to this encapsulation mode and the specifics on
how this mode is negotiated is specified in the companion
document, IPv4 support for Proxy Mobile IPv6 [ID-IPv4-PMIP6].
o IPv6-In-IPv4-UDP - IPv6 datagram encapsulation in an IPv4 UDP
packet. The details related to this mode are covered in the
companion document, IPv4 support for Proxy Mobile IPv6 [IPv4-
PMIP6-SPEC].
6.10.3. Routing State
The following section explain the routing state for a mobile node on
the mobile access gateway. This routing state reflects only one
specific way of implementation and one MAY choose to implement it in
other ways. The policy based route defined below acts as a traffic
selection rule for routing a mobile node's traffic through a specific
tunnel created between the mobile access gateway and that mobile
node's local mobility anchor and with the specific encapsulation
mode, as negotiated.
The below example identifies the routing state for two visiting
mobile nodes, MN1 and MN2 with their respective local mobility
anchors LMA1 and LMA2.
For all traffic from the mobile node, identified by the mobile node's
MAC address, ingress interface or source prefix (MN-HNP) to
_ANY_DESTINATION_ route via interface tunnel0, next-hop LMAA.
+==================================================================+
| Packet Source | Destination Address | Destination Interface |
+==================================================================+
| MAC_Address_MN1, | _ANY_DESTINATION_ | Tunnel0 |
| (IPv6 Prefix or |----------------------------------------------|
| Input Interface) | Locally Connected | Tunnel0 |
+------------------------------------------------------------------+
| MAC_Address_MN2 | _ANY_DESTINATION_ | Tunnel1 |
+ -----------------------------------------------|
| | Locally Connected | direct |
+------------------------------------------------------------------+
Example - Policy based Route Table
+==================================================================+
| Interface | Source Address | Destination Address | Encapsulation |
+==================================================================+
| Tunnel0 | Proxy-CoA | LMAA1 | IPv6-in-IPv6 |
+------------------------------------------------------------------+
| Tunnel1 |IPv4-Proxy-CoA | IPv4-LMA2 | IPv6-in-IPv4 |
+------------------------------------------------------------------+
Example - Tunnel Interface Table
6.10.4. Local Routing
If there is data traffic between a visiting mobile node and a
corresponding node that is locally attached to an access link
connected to the mobile access gateway, the mobile access gateway MAY
optimize on the delivery efforts by locally routing the packets and
by not reverse tunneling them to the mobile node's local mobility
anchor. However, this has an implication on the mobile node's
accounting and policy enforcement as the local mobility anchor is not
in the path for that traffic and it will not be able to apply any
traffic policies or do any accounting for those flows.
This decision of path optimization SHOULD be based on the configured
policy configured on the mobile access gateway, but enforced by the
mobile node's local mobility anchor. The specific details on how
this is achieved is beyond of the scope of this document.
6.10.5. Tunnel Management
All the considerations mentioned in Section 5.2, for the tunnel
management on the local mobility anchor apply for the mobile access
gateway as well.
As explained in Section 5.2, the life of the Proxy Mobile IPv6 tunnel
should not be based on a single visiting mobile node's lifetime. The
tunnel may get created as part of creating a mobility state for a
visiting mobile node and later the same tunnel may be associated with
other mobile nodes. So, the tearing down logic of the tunnel must be
based on the number of visitors over that tunnel.
6.10.6. Forwarding Rules
Upon receipt of an encapsulated packet sent to its configured Proxy-
CoA address i.e. on receiving a packet from a tunnel, the mobile
access gateway MUST use the destination address of the inner packet
for forwarding it to the interface where the prefix for that address
is hosted. The mobile access gateway MUST remove the outer header
before forwarding the packet. If the mobile access gateway cannot
find the connected interface for that destination address, it MUST
silently drop the packet. For reporting an error in such scenario,
in the form of ICMP control message, the considerations from Generic
Packet Tunneling specification [RFC-2473] apply.
On receiving a packet from a mobile node connected to its access
link, the mobile access gateway MUST ensure that there is an
established binding for that mobile node with its local mobility
anchor before forwarding the packet directly to the destination or
before tunneling the packet to the mobile node's local mobility
anchor.
On receiving a packet from a mobile node connected to its access
link, to a destination that is locally connected, the mobile access
gateway MUST check the configuration variable, EnableMAGLocalRouting,
to ensure the mobile access gateway is allowed to route the packet
directly to the destination. If the mobile access gateway is not
allowed to route the packet directly, it MUST route the packet
through the bi-directional tunnel established between itself and the
mobile's local mobility anchor.
On receiving a packet from the mobile node to any destination i.e.
not directly connected to the mobile access gateway, the packet MUST
be forwarded to the local mobility anchor through the bi-directional
tunnel established between itself and the mobile's local mobility
anchor. However, the packets that are sent with the link-local
source address MUST not be forwarded.
6.11. Interaction with DHCP Relay Agent
If Stateful Address Configuration using DHCP is supported on the link
on which the mobile node is attached, the DHCP relay agent [RFC-3315]
needs to be configured on the access router. When the mobile node
sends a DHCPv6 Request message, the relay agent function on the
access router MUST set the link-address field in the DHCPv6 message
to the mobile node's home network prefix, so as to provide a prefix to the mobile node's home network prefix, so as to provide a prefix
hint to the DHCP Server. On a point-to-point link, this is just a hint to the DHCP Server. Since, the access link is a point-to-point
normal DHCP relay agent configuration. However, on the shared links link with the configured mobile node's prefix as the on-link prefix,
supporting multiple mobile nodes with different home prefixes, there the normal DHCP relay agent configuration on the MAG will ensure the
is some interaction required between the relay agent and the mobile prefix hint is set to the mobile node's home network prefix.
access gateway, for setting the link-address field to the requesting
mobile node's home network prefix.
6.9. Mobile Node Detachment Detection and Resource Cleanup 6.12. Mobile Node Detachment Detection and Resource Cleanup
Before sending a Proxy Binding Update message to the local mobility Before sending a Proxy Binding Update message to the local mobility
anchor for extending the lifetime of a currently existing binding of anchor for extending the lifetime of a currently existing binding of
a mobile node, the mobile access gateway MUST make sure the mobile a mobile node, the mobile access gateway MUST make sure the mobile
node is still attached to the connected link by using some reliable node is still attached to the connected link by using some reliable
method. If the mobile access gateway cannot predictably detect the method. If the mobile access gateway cannot predictably detect the
presence of the mobile node on the connected link, it MUST NOT presence of the mobile node on the connected link, it MUST NOT
attempt to extend the registration lifetime of the mobile node. attempt to extend the registration lifetime of the mobile node.
Further, in such scenario, the mobile access gateway MUST terminate Further, in such scenario, the mobile access gateway MUST terminate
the binding of the mobile node by sending a Proxy Binding Update the binding of the mobile node by sending a Proxy Binding Update
message to the mobile node's local mobility anchor with lifetime message to the mobile node's local mobility anchor with lifetime
value set to 0. It MUST also remove any local state such as binding value set to 0. It MUST also remove any local state such as the
update list entry that was created for that mobile node. Binding Update List created for that mobile node.
The specific detection mechanism of the loss of a visiting mobile The specific detection mechanism of the loss of a visiting mobile
node on the connected link is specific to the access link between the node on the connected link is specific to the access link between the
mobile node and the mobile access gateway and is outside the scope of mobile node and the mobile access gateway and is outside the scope of
this document. Typically, there are various link-layer specific this document. Typically, there are various link-layer specific
events specific to each access technology that the mobile access events specific to each access technology that the mobile access
gateway can depend on for detecting the node loss. In general, the gateway can depend on for detecting the node loss. In general, the
mobile access gateway can depend on one or more of the following mobile access gateway can depend on one or more of the following
methods for the detection presence of the mobile node on the methods for the detection presence of the mobile node on the
connected link: connected link:
skipping to change at page 28, line 17 skipping to change at page 33, line 34
o PPP Session termination event on point-to-point link types o PPP Session termination event on point-to-point link types
o IPv6 Neighbor Unreachability Detection event from IPv6 stack o IPv6 Neighbor Unreachability Detection event from IPv6 stack
o Notification event from the local mobility anchor o Notification event from the local mobility anchor
o Absence of data traffic from the mobile node on the link for a o Absence of data traffic from the mobile node on the link for a
certain duration of time certain duration of time
6.10. Coexistence with Mobile Nodes using Host-based Mobility 6.13. Allowing network access to other IPv6 nodes
In some operating environments, network operators may want to In some proxy mobile IPv6 deployments, network operators may want to
provision the access link attached to the mobile access gateway to provision the mobile access gateway to offer network-based mobility
offer network-based mobility service only to some nodes and enable management service only to some visiting mobile nodes and enable just
normal IP access support for some other nodes on that link. This regular IPv6/IPv4 access to some other nodes attached to that mobile
specification supports access links with such mixture of nodes. The access gateway. This requires the network to have the control on
network has the control on when to enable the mobile node with the when to enable network-based mobility management service to a mobile
network mobility service. node and when to enabled a regular IPv6 access. This specification
does not disallow such configuration.
Upon obtaining the mobile node's profile after a successful access Upon obtaining the mobile node's profile after a successful access
authentication and after a policy consideration, the mobile access authentication and after a policy consideration, the mobile access
gateway MUST determine if the network based mobility service should gateway MUST determine if the network based mobility service should
be offered to that mobile node. If the mobile node is entitled for be offered to that mobile node. If the mobile node is entitled for
such service, then the network should ensure the mobile node believes such service, then the mobile access gateway must ensure the mobile
it is on its home link, as explained in various sections of this node believes it is on its home link, as explained in various
document. sections of this specification.
If the mobile node is not entitled for the network based mobility
service, as determined from the policy, the mobile access gateway
MUST ensure the mobile node can obtain an IPv6 address using normal
IPv6 address configuration mechanisms. The obtained address should
be from a local visitor network prefix. In other words the mobile
node should be able to operate as a traditional mobile node roaming
in a visitor network and with the ability to obtain an address from
the local visitor network prefix hosted on that link. This
essentially ensures, the proxy mobile IPv6 protocol will not impact
the behavior of a mobile node that is using host-based mobility, as
per [RFC-3775].
If the stateless address configuration mode is supported on that
link, the prefix information option in the router advertisements
should contain local visitor network prefix. If statefull address
configuration mode is enforced on the link and if DHCP is in used,
the mobile node should be able to obtain the IPv6 care-of address
from the local visitor network prefix.
If the link between the mobile access gateway and the mobile node is
a shared link, the Router Advertisement has to unicasted to the
mobile node with the destination address in the layer-2 header set to
the mobile's MAC address and the destination address in the IPv6
header set to the all-nodes multicast address.
6.11. Mobile Access Gateway Operation Summary
o After detecting a new mobile node on its access link and after the
successful access authentication and authorization of the mobile
node, the mobile access gateway MUST be able to able to access the
mobile node's profile. This may be downloaded from the local/
network policy store using MN-Identity or may be obtained as part
of a context transfer procedure. The mobile node's profile at the
minimum MUST have the mobile node's local mobility anchor address
and the MN-Identity. Optionally, it may have the mobile node's
home network prefix and other configuration parameters.
o The mobile access gateway MAY use one or more ways to detect the
attachment of a mobile node on to the link. The techniques can be
specific to the access technology or can be other generic events
as mentioned in the above sections.
o If the network determines that the mobile node will not be offered
the network-based mobility service, the mobile access gateway MUST
ensure that the Router Advertisements it sends will not contain
the mobile node's home prefix, but will be the hosted on-link
prefix. Also, if the mobile node attempts to obtain an IPv6
address, the mobile access gateway or the DHCP relay agent on the
link MUST ensure that the prefix hint that gets added to the DHCP
message will be of the local hosted prefix.
o `The mobile access gateway on receiving a Router Solicitation
message from a mobile node MUST send a Router Advertisement
message containing the mobile node's home network prefix.
o The mobile access gateway MUST send the periodic Router
Advertisement messages, as per the ND specification [RFC-2461],
advertising the mobile node's home network prefix on the access
link.
o If the link between the mobile node and the mobile access gateway
is a shared-link, then the Router Advertisement MUST be unicasted
to the mobile node by setting the destination address in the link-
layer header to the mobile node's MAC address and with the
destination address in the IPv6 header set to the all-nodes
multicast address.
o If the mobile node uses DHCP for address configuration, the mobile
access gateway or specifically the DHCP relay agent on the link
MUST ensure the DHCPv4/v6 packets are properly tagged with the
sending mobile node's MN-HoA, as the prefix hint.
o The Proxy Binding Update message that the mobile access gateway
sends to the local mobility anchor, MUST have the configured IPv6
address of the egress interface. The Proxy Binding Update message
MUST have the NAI option identifying the mobile node, home network
prefix option and optionally the time stamp option. If the home
network prefix option is set to value 0, the local mobility anchor
will assign the home network prefix and will return them in the
Proxy Binding Acknowledgment. This message MUST be protected by
using IPSec security association created between the mobile access
gateway and local mobility anchor.
o After receiving a Proxy Binding Acknowledgment with the status
code indicating the acceptance of the Binding Update, the mobile
access gateway MUST setup a tunnel to the mobile node's local
mobility anchor, as explained in the above sections, if there is
exists no tunnel. The mobile access gateway MUST also add a
default route over the tunnel for all the traffic from the mobile
node.
o If the local mobility anchor denies the Proxy Binding Update
request, the mobile access gateways MUST NOT advertise the mobile
node's home prefix on the access link and there by denying
mobility service to the mobile node.
o Before attempting to extend binding lifetime of a mobile node, the
mobile access gateway MUST make sure the mobile node is still
attached to the connected link by using some reliable method. If
the mobile access gateway cannot predictably detect the presence
of the mobile node on the connected link, it MUST NOT attempt to
extend the registration lifetime of the mobile node. Also, it
MUST terminate the binding of the mobile node by sending a Proxy
Binding Update message to the mobile node's local mobility anchor
with lifetime value set to 0.
o At any point, if the mobile access gateway detects that the mobile If the mobile node is not entitled for the network-based mobility
node has roamed away from its access link, it MUST send a Proxy management service, as enforced by the policy, the mobile access
Binding Update to the local mobility anchor with the lifetime gateway MAY choose to offer regular IPv6 access to the mobile node
value set to 0 and it must also remove the default route over the and hence the normal IPv6 considerations apply. If IPv6 access is
tunnel for that mobile and also remove the Binding Update list enabled, the mobile node SHOULD be able to obtain any IPv6 address
entry and any other local state created for that mobile node. using normal IPv6 address configuration mechanisms. The obtained
address must be from a local visitor network prefix. This
essentially ensures, the mobile access gateway functions as any other
access router and does not impact the protocol operation of a mobile
node attempting to use host-based mobility management service when it
attaches to an access link connected to a mobile access gateway in a
proxy mobile IPv6 domain.
7. Mobile Node Operation 7. Mobile Node Operation
The Network-based mobility scheme defined in this document, allows a This non-normative section discusses the mobile node's operation in a
mobile node to obtain IP mobility within the proxy mobile IPv6 Proxy Mobile IPv6 domain.
domain, with out requiring the mobile node to involve in any mobility
management.
When a mobile node enters a proxy mobile IPv6 domain and attached to
an access link, the network identifies the mobile node as part of the
access authentication and establishes an identity for the mobile
node. This identity has a binding to a cryptographic state and
potentially associating the mobile node's link-layer address of the
attached interface. The specifics on how this is achieved is beyond
the scope of this document and is very much specific to the access
technology and depends on the applied security protocols in place.
For all practical purposes, this document assumes that the mobile
node's access to the network is secure.
Once the mobile node enters a Proxy Mobile IPv6 domain and attaches Once the mobile node enters a Proxy Mobile IPv6 domain and attaches
to an access network, the network identifies the mobile as part of to an access network and after the access authentication, the network
the access authentication procedure and ensures the mobile using any ensures, the mobile using any of the address configuration mechanisms
of the address configuration mechanisms permitted by the network for permitted by the network for that mobile node, will be able to obtain
that mobile, will be able to obtain an address and move anywhere in an address and move anywhere in that proxy mobile IPv6 domain. From
that managed domain. From the perspective of the mobile, the entire the perspective of the mobile, the entire proxy mobile IPv6 domain
Proxy Mobile IPv6 domain appears as a single link, the network appears as a single link, the network ensures the mobile believes it
ensures the mobile believes it is always on the same link. is always on the same link.
The mobile node can be operating in an IPv4-only mode, IPv6-only mode The mobile node can be operating in an IPv4-only mode, IPv6-only mode
or in dual IPv4/IPv6 mode. Typically, the configured policy in the or in dual IPv4/IPv6 mode. However, the specific details on how the
network determines the type of home address(es) i.e. MN-HoA, IPv4 IPv4 network-based mobility management service is offered to the
MN-HoA or both, that the network mobility is supported for. If the mobile node is specified in the companion document, IPv4 Support for
configured policy for a mobile node is for IPv6-only home address Proxy Mobile IPv6 [ID-IPV4-PMIP6].
mobility, the mobile node will be able to obtain its MN-HoA, any
where in that proxy mobile IPv6 domain and if policy allows only Typically, the configured policy in the network determines if the
IPv4-only home address mobility, the mobile node will be able to mobile node is authorized for IPv6, IPv4 or IPv6/IPv4 home address
obtain its IPv4 MN-HoA, any where in that domain. Similarly, if the mobility. If the configured policy for a mobile node is for IPv6-
policy permits both the IPv4 and IPv6 home address mobility, the only home address mobility, the mobile node will be able to obtain
mobile node will be able to obtain its MN-HoA and IPv4 MN-HoA and its IPv6 home address, any where in that Proxy Mobile IPv6 domain,
move anywhere in the network. However, if the mobile node is otherwise the obtained address will be from a local prefix and not
configured for IPv6-only mobility and if the mobile node attempts to from a prefix that is topologically anchored at the local mobility
obtain an IPv4 address configuration via DHCP mechanism, the obtained anchor and hence the mobile will loose that address after it moves to
address configuration will not have any mobility properties, i.e. the a new link.
obtained address will be from a local prefix and not from a prefix
that is topologically anchored at the local mobility anchor and hence
the mobile will loose that address as it moves to a different link.
The specifics on how this is achieved is the operational logic of the
mobile access gateway on the access link.
7.1. Booting up in a Proxy Mobile IPv6 Domain 7.1. Booting up in a Proxy Mobile IPv6 Domain
When a mobile node moves into a proxy mobile IPv6 domain and attaches When a mobile node moves into a proxy mobile IPv6 domain and attaches
to an access link, the mobile node will present its identity, MN- to an access link, the mobile node will present its identity, MN-
Identity, to the network as part of the access authentication Identity, to the network as part of the access authentication
procedure. Once the authentication procedure is complete and the procedure. Once the authentication procedure is complete and the
mobile node is authorized to access the network, the network or mobile node is authorized to access the network, the network or
specifically the mobile access gateway on the access link will have specifically the mobile access gateway on the access link will have
the mobile node's profile and so it would know the mobile node's home the mobile node's profile and so it would know the mobile node's home
skipping to change at page 32, line 31 skipping to change at page 35, line 22
the mobile node's local mobility anchor and the same may be learnt by the mobile node's local mobility anchor and the same may be learnt by
the mobile access gateway. the mobile access gateway.
If the mobile node is IPv6 enabled, on attaching to the link and If the mobile node is IPv6 enabled, on attaching to the link and
after access authentication, the mobile node typically would send a after access authentication, the mobile node typically would send a
Router Solicitation message. The mobile access gateway on the Router Solicitation message. The mobile access gateway on the
attached link will respond to the Router Solicitation message with a attached link will respond to the Router Solicitation message with a
Router Advertisement. The Router Advertisement will have the mobile Router Advertisement. The Router Advertisement will have the mobile
node's home network prefix, default-router address and other address node's home network prefix, default-router address and other address
configuration parameters. The address configuration parameters such configuration parameters. The address configuration parameters such
as Managed Address Configuration, Statefull Configuration flag values as Managed Address Configuration, Stateful Configuration flag values
will typically be consistent through out that domain for that mobile will typically be consistent through out that domain for that mobile
node. node.
If the Router Advertisement has the Managed Address Configuration If the Router Advertisement has the Managed Address Configuration
flag set, the mobile node, as it would normally do, will send a flag set, the mobile node, as it would normally do, will send a
DHCPv6 Request and the mobile access gateway on that access link will DHCPv6 Request and the mobile access gateway on that access link will
ensure, the mobile node node gets the MN-HoA as a lease from the DHCP ensure, the mobile node gets an address from its home network prefix
server. as a lease from the DHCP server.
If the Router Advertisement does not have the Managed Address If the Router Advertisement does not have the Managed Address
Configuration flag set and if the mobile node is allowed to use an Configuration flag set and if the mobile node is allowed to use an
autoconfigured address, the mobile node will generate an interface autoconfigured address, the mobile node will generate an interface
identifier, as per the Autoconf specification [RFC-2462] or using identifier, as per the Autoconf specification [RFC-2462] or using
privacy extensions as specified in Privacy Extensions specification privacy extensions as specified in Privacy Extensions specification
[RFC-3041]. [RFC-3041].
If the mobile node is IPv4 enabled or IPv4-only enabled, the mobile If the mobile node is IPv4 enabled or IPv4-only enabled, the mobile
node after the access authentication, will be able to obtain the IPv4 node after the access authentication, will be able to obtain the IPv4
address configuration for the connected interface by using DHCPv4. address configuration for the connected interface by using DHCPv4.
Once the address configuration is complete, the mobile node will have Once the address configuration is complete, the mobile node can
the MN-HoA, IPv4 MN-HoA or both, that it can continue to use as long continue to use the obtained address configuration as long as it is
as it is with in the scope of that proxy mobile IPv6 domain. with in the scope of that Proxy Mobile IPv6 domain.
7.2. Roaming in the Proxy Mobile IPv6 Network 7.2. Roaming in the Proxy Mobile IPv6 Network
After booting in the Proxy Mobile IPv6 domain and obtaining the After booting in the Proxy Mobile IPv6 domain and obtaining the
address configuration, the mobile node as it roams in the network address configuration, the mobile node as it roams in the network
between access links, will always detect its home network prefix on between access links, will always detect its home network prefix on
the link, as long as the attached access network is in the scope of the link, as long as the attached access network is in the scope of
that proxy mobile IPv6 domain. The mobile node can continue to use that Proxy Mobile IPv6 domain. The mobile node can continue to use
its IPv4/IPv6 MN-HoA for sending and receiving packets. If the its IPv4/IPv6 MN-HoA for sending and receiving packets. If the
mobile node uses DHCP for address configuration, it will always be mobile node uses DHCP for address configuration, it will always be
able to obtain its MN-HoA using DHCP. However, the mobile node will able to obtain its MN-HoA using DHCP. However, the mobile node will
always detect a new default-router on each connected link, but still always detect a new default-router on each connected link, but still
advertising the mobile node's home prefix as the on-link prefix and advertising the mobile node's home network prefix as the on-link
with the other configuration parameters consistent with the link prefix and with the other configuration parameters consistent with
properties as before. its home link properties.
7.3. IPv6 Host Protocol Parameters 7.3. IPv6 Host Protocol Parameters
This specification assumes the mobile node to be a normal IPv6 node, This specification assumes the mobile node to be a normal IPv6 node,
with its protocol operation consistent with the base IPv6 with its protocol operation consistent with the base IPv6
specification [RFC-2460]. All aspects of Neighbor Discovery specification [RFC-2460]. All aspects of Neighbor Discovery
Protocol, including Router Discovery, Neighbor Discovery, Address Protocol, including Router Discovery, Neighbor Discovery, Address
Configuration procedures will just remain consistent with the base Configuration procedures will just remain consistent with the base
IPv6 Neighbor Discovery Specification [RFC-2461]. However, this IPv6 Neighbor Discovery Specification [RFC-2461]. However, this
specification recommends that the following IPv6 operating parameters specification recommends that the following IPv6 operating parameters
skipping to change at page 34, line 12 skipping to change at page 36, line 46
one link to another, the received Router Advertisement messages one link to another, the received Router Advertisement messages
advertising the mobile's home network prefix will be from a different advertising the mobile's home network prefix will be from a different
link-local address and thus making the mobile node believe that there link-local address and thus making the mobile node believe that there
is a new default-router on the link. It is important that the mobile is a new default-router on the link. It is important that the mobile
node uses the newly learnt default-router as supposed to the node uses the newly learnt default-router as supposed to the
previously learnt default-router. The mobile node must update its previously learnt default-router. The mobile node must update its
default-router list with the new default router entry and must age default-router list with the new default router entry and must age
out the previously learnt default router entry from its cache, just out the previously learnt default router entry from its cache, just
as specified in Section 6.3.5 of the base IPv6 ND specification [RFC- as specified in Section 6.3.5 of the base IPv6 ND specification [RFC-
2461]. This action is critical for minimizing packet losses during a 2461]. This action is critical for minimizing packet losses during a
hand off switch hand off switch.
On detecting a reachability problem, the mobile node will certainly On detecting a reachability problem, the mobile node will certainly
detect the neighbor or the default-router unreachability by detect the neighbor or the default-router unreachability by
performing a Neighbor Unreachability Detection procedure, but it is performing a Neighbor Unreachability Detection procedure, but it is
important that the mobile node times out the previous default router important that the mobile node times out the previous default router
entry at the earliest. If a given IPv6 host implementation has the entry at the earliest. If a given IPv6 host implementation has the
provision to adjust these flush timers, still conforming to the base provision to adjust these flush timers, still conforming to the base
IPv6 ND specification, it is desirable to keep the flush-timers to IPv6 ND specification, it is desirable to keep the flush-timers to
suit the above consideration. suit the above consideration.
However, if the mobile access gateway has the ability to with draw However, if the mobile access gateway has the ability to withdraw the
the previous default-router entry, by multicasting a Router previous default-router entry, by sending a Router Advertisement
Advertisement using the link-local address that of the previous using the link-local address that of the previous mobile access
mobility proxy agent and with the Router Lifetime field set to value gateway and with the Router Lifetime field set to value 0, then it is
0, then it is possible to force the flush out of the Previous possible to force the flush of the Previous Default-Router entry from
Default-Router entry from the mobile node's cache. This certainly the mobile node's cache. This certainly requires some context-
requires some context-transfer mechanisms in place for notifying the transfer mechanisms in place for notifying the link-local address of
link-local address of the default-router on the previous link to the the default-router on the previous link to the mobile access gateway
mobile access gateway on the new link. on the new link.
There are other solutions possible for this problem, including the There are other solutions possible for this problem, including the
assignment of a unique link-local address for all the access routers assignment of a unique link-local address for all the mobile access
in the Proxy Mobile IPv6 Network. In either case, this is an gateways in a Proxy Mobile IPv6 domain. In any case, this is an
implementation choice and has no bearing on the protocol implementation choice and has no bearing on the protocol
interoperability. Implementations are free to adopt the best interoperability. Implementations are free to adopt the best
approach that suits their target deployments. approach that suits their target deployments.
8. Message Formats 8. Message Formats
This section defines extensions to the Mobile IPv6 [RFC-3775] This section defines extensions to the Mobile IPv6 [RFC-3775]
protocol messages. protocol messages.
8.1. Proxy Binding Update 8.1. Proxy Binding Update
skipping to change at page 35, line 18 skipping to change at page 37, line 45
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 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sequence # | | Sequence # |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|A|H|L|K|M|R|P| Reserved | Lifetime | |A|H|L|K|M|R|P| Reserved | Lifetime |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | |
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 6: Proxy Binding Update Message Figure 9: Proxy Binding Update Message
A Binding Update message that is sent by mobile access gateway is A Binding Update message that is sent by mobile access gateway is
referred to as the Proxy Binding Update message. referred to as the Proxy Binding Update message.
Proxy Registration Flag (P) Proxy Registration Flag (P)
The Proxy Registration Flag is set to indicate to the local mobility The Proxy Registration Flag is set to indicate to the local mobility
anchor that the Binding Update is from a mobile access gateway acting anchor that the Binding Update is from a mobile access gateway acting
as a proxy mobility agent. The flag MUST be set to the value of 1 as a proxy mobility agent. The flag MUST be set to the value of 1
for proxy registrations and MUST be set to 0 for direct registration for proxy registrations and MUST be set to 0 for direct registrations
send my a mobile node using host-base mobility. sent by a mobile node when using host-base mobility.
For descriptions of other fields present in this message, refer to For descriptions of other fields present in this message, refer to
the section 6.1.7 of Mobile IPv6 specification [RFC3775]. the section 6.1.7 of Mobile IPv6 specification [RFC3775].
8.2. Proxy Binding Acknowledgment 8.2. Proxy Binding Acknowledgment
0 1 2 3 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 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Status |K|R|P|Reserved | | Status |K|R|P|Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sequence # | Lifetime | | Sequence # | Lifetime |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | |
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
skipping to change at page 36, line 15 skipping to change at page 38, line 31
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 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Status |K|R|P|Reserved | | Status |K|R|P|Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sequence # | Lifetime | | Sequence # | Lifetime |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | |
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 7: Proxy Binding Acknowledgment Message Figure 10: Proxy Binding Acknowledgment Message
A Binding Acknowledgment message that is sent by the local mobility
anchor to the mobile access gateway is referred to as "Proxy Binding
Acknowledgement".
Proxy Registration Flag (P) Proxy Registration Flag (P)
A new flag (P) is included in the Binding Acknowledgement message to A new flag (P) is included in the Binding Acknowledgement message to
indicate that the local mobility anchor Agent that processed the indicate that the local mobility anchor that processed the
corresponding Binding Update supports Proxy Registrations. The flag corresponding Proxy Binding Update message supports Proxy
is set only if the corresponding Proxy Binding Update had the Proxy Registrations. The flag is set only if the corresponding Proxy
Registration Flag (P) set to 1. The rest of the Binding Binding Update had the Proxy Registration Flag (P) set to value of 1.
Acknowledgement format remains the same, as defined in [RFC-3775]. The rest of the Binding Acknowledgement format remains the same, as
defined in [RFC-3775].
For descriptions of other fields present in this message, refer to For descriptions of other fields present in this message, refer to
the Mobile IPv6 base specificatoin [RFC-3775]. the section 6.1.8 of Mobile IPv6 specification [RFC3775].
A Binding Acknowledgment message that is sent by the mobile access
gateway is also referred to as "Proxy Binding Acknowledgement".
8.3. Home Network Prefix Option 8.3. Home Network Prefix Option
A new option, Home Network Prefix Option is defined for using it in A new option, Home Network Prefix Option is defined for using it in
the Proxy Binding Update and Acknowledgment messages exchanged the Proxy Binding Update and Acknowledgment messages exchanged
between the local mobility anchor to the mobile access gateway. This between the local mobility anchor and the mobile access gateway.
option can be used for exchanging the mobile node's home prefix and This option can be used for exchanging the mobile node's home network
home address information. prefix information.
The home network prefix Option has an alignment requirement of 8n+4. The home network prefix Option has an alignment requirement of 8n+4.
Its format is as follows: Its format is as follows:
0 1 2 3 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 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 | Prefix Length | | Type | Length | Reserved | Prefix Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | |
skipping to change at page 37, line 36 skipping to change at page 40, line 36
MUST be set to 18. MUST be set to 18.
Reserved Reserved
This field is unused for now. The value MUST be initialized This field is unused for now. The value MUST be initialized
to 0 by the sender and MUST be ignored by the receiver. to 0 by the sender and MUST be ignored by the receiver.
Prefix Length Prefix Length
8-bit unsigned integer indicating the prefix length of the 8-bit unsigned integer indicating the prefix length of the
IPv6 prefix contained in the option. If the prefix length IPv6 prefix contained in the option.
is set to the value 128, indicates the presence of the
mobile node's 128-bit home address.
Home Network Prefix Home Network Prefix
A sixteen-byte field containing the Home Network Prefix A sixteen-byte field containing the mobile node's IPv6 Home
Network Prefix.
Figure 8: Home Network Prefix Option Figure 11: Home Network Prefix Option
8.4. Time Stamp Option 8.4. Time Stamp Option
A new option, Time Stamp Option is defined for use in Proxy Binding A new option, Time Stamp Option is defined for use in the Proxy
Update and Acknowledgement messages. This option MUST be present in Binding Update and Acknowledgement messages. This option can be used
all Proxy Binding Update and Acknowledgement messages. in Proxy Binding Update and Proxy Binding Acknowledgement messages.
0 1 2 3 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 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Option Type | Option Length | | Option Type | Option Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | |
+ Timestamp + + Timestamp +
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type Type
<IANA> <IANA>
Length Length
8-bit unsigned integer indicating the length in octets of 8-bit unsigned integer indicating the length in octets of
the option, excluding the type and length fields. This field the option, excluding the type and length fields. This field
MUST be set to 18. MUST be set to 8.
Timestamp Timestamp
64-bit time stamp 64-bit time stamp
Figure 9: Time Stamp Option Figure 12: Time Stamp Option
8.5. Status Codes 8.5. Status Codes
This document defines the following new Binding Acknowledgement This document defines the following new Binding Acknowledgement
status values: status values:
145: Proxy Registration not supported by the local mobility anchor 145: Proxy Registration not supported by the local mobility anchor
146: Proxy Registrations from this mobile access gateway not allowed 146: Proxy Registrations from this mobile access gateway not allowed
147: No home address for this NAI is configured and the Home Network 147: Home Network prefix for this NAI is not configured and the Home
Prefix Option not present in the Binding Update. Network Prefix Option not present in the Proxy Binding Update.
148: Invalid Time Stamp Option in the Binding Update 148: Invalid Time Stamp Option in the received Proxy Binding Update
message.
Status values less than 128 indicate that the Binding Update was Status values less than 128 indicate that the Binding Update was
processed successfully by the receiving nodes. Values greater than processed successfully by the receiving nodes. Values greater than
128 indicate that the Binding Update was rejected by the local 128 indicate that the Binding Update was rejected by the local
mobility anchor. mobility anchor.
The value allocation for this usage needs to be approved by the IANA The value allocation for this usage needs to be approved by the IANA
and must be updated in the IANA registry. and must be updated in the IANA registry.
9. IANA Considerations 9. Protocol Configuration Variables
This document defines a new Mobility Header Option, the Mobile Home The mobile access gateway MUST allow the following variables to be
Network Prefix Option. This option is described in Section 8.3. The configured by the system management.
Type value for this option needs to be assigned from the same
numbering space as allocated for the other mobility options defined
in [RFC-3775].
This document defines a new Mobility Header Option, the Time Stamp EnableMAGLocalrouting
Option. This option is described in Section 8.4. The type value for
this option needs to be assigned from the same numbering space as This flag indicates whether or not the mobile access gateway is
allocated for the other mobility options defined in [RFC-3775]. allowed to enable local routing of the traffic exchanged between a
visiting mobile node and a corresponding node that is locally
connected to one of the interfaces of the mobile access gateway. The
corresponding node can be another visiting mobile node as well, or a
local fixed node.
The default value for this flag is set to "FALSE", indicating that
the mobile access gateway MUST reverse tunnel all the traffic to the
mobile node's local mobility anchor.
When the value of this flag is set to "TRUE", the mobile access
gateway MUST route the traffic locally.
This aspect of local routing MAY be defined as policy on a per mobile
basis and when present will take precedence over this flag.
10. IANA Considerations
This document defines a two new Mobility Header Options, the Home
Network Prefix Option and the Time Stamp Option. These options are
described in Sections 8.3 and 8.5 respectively. The Type value for
these options needs to be assigned from the same numbering space as
allocated for the other mobility options, as defined in [RFC-3775].
This document also defines new Binding Acknowledgement status values This document also defines new Binding Acknowledgement status values
as described in Section 8.5. The status values MUST be assigned from as described in Section 8.5. The status values MUST be assigned from
the same space used for Binding Acknowledgement status values in the same space used for Binding Acknowledgement status values, as
[RFC-3775]. defined in [RFC-3775].
10. Security Considerations 11. Security Considerations
The security threats against any general network-based mobility The potential security threats against any general network-based
management protocol are covered in the document, Security Threats to mobility management protocol are covered in the document, Security
Network-Based Localized Mobility Management Threats to Network-Based Localized Mobility Management [RFC-4832].
[draft-ietf-netlmm-threats-04.txt]. This section analyses those This section analyses those vulnerabilities in the context of Proxy
vulnerabilities in the context of Proxy Mobile IPv6 protocol and Mobile IPv6 protocol solution and covers all aspects around those
covers all aspects around those identified vulnerabilities. identified vulnerabilities.
A compromised mobile access gateway can send Proxy Binding Update A compromised mobile access gateway can potentially send Proxy
requests for mobile nodes that are not attached to its access link. Binding Update messages on behalf of the mobile nodes that are not
This threat is similar to an attack on a typical routing protocol or attached to its access link. This threat is similar to an attack on
equivalent to the compromise of a on-path router and hence this a typical routing protocol or equivalent to the compromise of an on-
threat exists in the network today and this specification does not path router. This threat exists in the network today and this
make this vulnerability any worse than what it is. However, to specification does not make this vulnerability any worse than what it
eliminate this attack, the local mobility anchor can ensure that the is. However, to eliminate this vulnerability, the local mobility
mobile node is attached to the access link of the requesting mobile anchor before accepting Proxy Binding Update message received from a
access gateway. This can be achieved using out of band mechanisms, mobile access gateway, MUST ensure the mobile node is attached to the
such as from the mobile node's access authentication to the network mobile access gateway that sent the Proxy Binding Update message.
and the specifics of how that is achieved is beyond the scope of this This can be achieved using out of band mechanisms and the specifics
document. of how that is achieved is beyond the scope of this document.
This document does not cover the security requirements for This document does not cover the security requirements for
authorizing the mobile node for the use of the access link. It is authorizing the mobile node for the use of the access link. It is
assumed that there are proper Layer-2 based authentication assumed that there are proper Layer-2/Layer-3 based authentication
procedures, such as EAP, in place and will ensure the mobile node is procedures, such as EAP, are in place and will ensure the mobile node
properly identified and authorized before permitting it to access the is properly identified and authorized before permitting it to access
network. It is further assumed that the same security mechanism will the network. It is further assumed that the same security mechanism
ensure the mobile session is not hijacked by malicious nodes on the will ensure the mobile session is not hijacked by malicious nodes on
access link. the access link.
This specification requires that all the signaling messages exchanged This specification requires that all the signaling messages exchanged
between the mobile access gateway and the local mobility anchor MUST between the mobile access gateway and the local mobility anchor MUST
be authenticated by IPsec [RFC-4301]. The use of IPsec to protect be authenticated by IPsec [RFC-4301]. The use of IPsec to protect
Mobile IPv6 signaling messages is described in detail in the HA-MN Mobile IPv6 signaling messages is described in detail in the HA-MN
IPsec specification [RFC-3776] and the extension of that security IPsec specification [RFC-3776] and the applicability of that security
model to Proxy Mobile IPv6 is covered in Section 4.0 of this model to Proxy Mobile IPv6 protocol is covered in Section 4.0 of this
document. document.
As described in the base Mobile IPv6 specification [RFC-3775], As described in the base Mobile IPv6 specification [RFC-3775], both
Section 5.1 both the mobile client (in this case, its the mobile the mobile node (in case of Proxy Mobile IPv6, its the mobile access
access gateway) and the local mobility anchor MUST support and SHOULD gateway) and the local mobility anchor MUST support and SHOULD use
use the Encapsulating Security Payload (ESP) header in transport mode the Encapsulating Security Payload (ESP) header in transport mode and
and MUST use a non-NULL payload authentication algorithm to provide MUST use a non-NULL payload authentication algorithm to provide data
data origin authentication, data integrity and optional anti-replay origin authentication, data integrity and optional anti-replay
protection. protection.
The proxy solution allows one device creating a routing state for The proxy solution allows one device creating a routing state for
some other device at the local mobility anchor. It is important that some other device at the local mobility anchor. It is important that
the local mobility anchor has proper authorization services in place the local mobility anchor has proper authorization services in place
to ensure a given mobile access gateway is permitted to be a proxy to ensure a given mobile access gateway is permitted to be a proxy
for a specific mobile node. If proper security checks are not in for a specific mobile node. If proper security checks are not in
place, a malicious node may be able to hijack a session or may do a place, a malicious node may be able to hijack a session or may do a
denial-of-service attacks. denial-of-service attacks.
11. Acknowledgements 12. Acknowledgements
The authors would like to specially thank Julien Laganier, Christian The authors would like to specially thank Julien Laganier, Christian
Vogt, Pete McCann, Brian Haley and Ahmad Muhanna for their thorough Vogt, Pete McCann, Brian Haley, Ahmad Muhanna, JinHyeock Choi for
review of this document. their thorough review of this document.
The authors would also like to thank the Gerardo Giaretta, Kilian The authors would also like to thank the Gerardo Giaretta, Kilian
Weniger, Alex Petrescu, Mohamed Khalil, Fred Templing, Nishida Weniger, Alex Petrescu, Mohamed Khalil, Fred Templing, Nishida
Katsutoshi, James Kempf, Vidya Narayanan, Henrik Levkowetz, Phil Katsutoshi, James Kempf, Vidya Narayanan, Henrik Levkowetz, Phil
Roberts, Jari Arkko, Ashutosh Dutta, Hesham Soliman, Behcet Sarikaya, Roberts, Jari Arkko, Ashutosh Dutta, Hesham Soliman, Behcet Sarikaya,
George Tsirtsis and many others for their passionate discussions in George Tsirtsis and many others for their passionate discussions in
the working group mailing list on the topic of localized mobility the working group mailing list on the topic of localized mobility
management solutions. These discussions stimulated much of the management solutions. These discussions stimulated much of the
thinking and shaped the draft to the current form. We acknowledge thinking and shaped the draft to the current form. We acknowledge
that ! that !
The authors would also like to thank Ole Troan, Akiko Hattori, Perviz The authors would also like to thank Ole Troan, Akiko Hattori, Parviz
Yegani, Mark Grayson, Michael Hammer, Vojislav Vucetic, Jay Iyer and Yegani, Mark Grayson, Michael Hammer, Vojislav Vucetic, Jay Iyer and
Tim Stammers for their input on this document. Tim Stammers for their input on this document.
12. References 13. References
12.1. Normative References 13.1. Normative References
[RFC-1305] Mills, D., "Network Time Protocol (Version 3) [RFC-1305] Mills, D., "Network Time Protocol (Version 3)
Specification, Implementation", RFC 1305, March 1992. Specification, Implementation", RFC 1305, March 1992.
[RFC-2460] Deering, S. and R. Hinden, "Internet Protocol, Version 6 [RFC-2460] Deering, S. and R. Hinden, "Internet Protocol, Version 6
(IPv6) Specification", RFC 2460, December 1998. (IPv6) Specification", RFC 2460, December 1998.
[RFC-2461] Narten, T., Nordmark, E. and W. Simpson, "Neighbor [RFC-2461] Narten, T., Nordmark, E. and W. Simpson, "Neighbor
Discovery for IP Version 6 (IPv6)", RFC 2461, December 1998. Discovery for IP Version 6 (IPv6)", RFC 2461, December 1998.
skipping to change at page 42, line 19 skipping to change at page 45, line 20
[RFC-4301] Kent, S. and Atkinson, R., "Security Architecture for the [RFC-4301] Kent, S. and Atkinson, R., "Security Architecture for the
Internet Protocol", RFC 4301, December 2005. Internet Protocol", RFC 4301, December 2005.
[RFC-4303] Kent, S. "IP Encapsulating Security Protocol (ESP)", RFC [RFC-4303] Kent, S. "IP Encapsulating Security Protocol (ESP)", RFC
4303, December 2005. 4303, December 2005.
[RFC-4306] Kaufman, C, et al, "Internet Key Exchange (IKEv2) [RFC-4306] Kaufman, C, et al, "Internet Key Exchange (IKEv2)
Protocol", RFC 4306, December 2005. Protocol", RFC 4306, December 2005.
[draft-ietf-netlmm-nohost-req-05.txt] Kempf, J., Leung, K., Roberts, [RFC-4830] Kempf, J., Leung, K., Roberts, P., Nishida, K., Giaretta,
P., Nishida, K., Giaretta, G., Liebsch, M., "Goals for Network-based G., Liebsch, M., "Problem Statement for Network-based Localized
Localized Mobility Management", October 2006. Mobility Management", September 2006.
[draft-ietf-netlmm-nohost-ps-05.txt] Kempf, J., Leung, K., Roberts, [RFC-4831] Kempf, J., Leung, K., Roberts, P., Nishida, K., Giaretta,
P., Nishida, K., Giaretta, G., Liebsch, M., "Problem Statement for G., Liebsch, M., "Goals for Network-based Localized Mobility
Network-based Localized Mobility Management", September 2006. Management", October 2006.
[draft-ietf-netlmm-threats-04.txt] Vogt, C., Kempf, J., "Security [RFC-4832] Vogt, C., Kempf, J., "Security Threats to Network-Based
Threats to Network-Based Localized Mobility Management", September Localized Mobility Management", September 2006.
2006.
[draft-ietf-mip6-nemo-v4traversal-03.txt] Soliman, H. et al, "Mobile [ID-IPV4-PMIP6] Wakikawa, R. and Gundavelli, S., "IPv4 Support for
IPv6 support for dual stack Hosts and Routers (DSMIPv6)", October Proxy Mobile IPv6", draft-ietf-netlmm-pmip6-ipv4-support-00.txt, May
2006. 2007.
12.2. Informative References [ID-DSMIP6] Soliman, H. et al, "Mobile IPv6 support for dual stack
Hosts and Routers (DSMIPv6)",
draft-ietf-mip6-nemo-v4traversal-03.txt, October 2006.
13.2. Informative References
[RFC-1332] McGregor, G., "The PPP Internet Protocol Control Protocol [RFC-1332] McGregor, G., "The PPP Internet Protocol Control Protocol
(IPCP)", RFC 1332, May 1992. (IPCP)", RFC 1332, May 1992.
[RFC-1661] Simpson, W., Ed., "The Point-To-Point Protocol (PPP)", STD [RFC-1661] Simpson, W., Ed., "The Point-To-Point Protocol (PPP)", STD
51, RFC 1661, July 1994. 51, RFC 1661, July 1994.
[RFC-2472] Haskin, D. and Allen, E., "IP version 6 over PPP", RFC [RFC-2472] Haskin, D. and Allen, E., "IP version 6 over PPP", RFC
2472, December 1998. 2472, December 1998.
skipping to change at page 43, line 12 skipping to change at page 46, line 14
[RFC-3041] Narten, T. and Draves, R., "Privacy Extensions for [RFC-3041] Narten, T. and Draves, R., "Privacy Extensions for
Stateless Address Autoconfiguration in IPv6", RFC 3041, January 2001. Stateless Address Autoconfiguration in IPv6", RFC 3041, January 2001.
[RFC-3344] Perkins, C., "IP Mobility Support for IPv4", RFC 3344, [RFC-3344] Perkins, C., "IP Mobility Support for IPv4", RFC 3344,
August 2002. August 2002.
[RFC-3756] Nikander, P., Kempf, J., and E. Nordmark, "IPv6 Neighbor [RFC-3756] Nikander, P., Kempf, J., and E. Nordmark, "IPv6 Neighbor
Discovery (ND) Trust Models and Threats", RFC 3756, May 2004. Discovery (ND) Trust Models and Threats", RFC 3756, May 2004.
[draft-iab-multilink-subnet-issues-03.txt] Thaler, D., "Multilink [ID-DNAV6] Kempf, J., et al "Detecting Network Attachment in IPv6
Subnet Issues", January 2006. Networks (DNAv6)", draft-ietf-dna-protocol-03.txt, October 2006.
[draft-ietf-dna-protocol-03] Kempf, J., et al "Detecting Network
Attachment in IPv6 Networks (DNAv6)", draft-ietf-dna-protocol-03,
October 2006.
[draft-ietf-mip6-ikev2-ipsec-08] Devarapalli, V. and Dupont, F., [ID-MIP6-IKEV2] Devarapalli, V. and Dupont, F., "Mobile IPv6
"Mobile IPv6 Operation with IKEv2 and the revised IPsec Operation with IKEv2 and the revised IPsec Architecture",
Architecture", December 2006. draft-ietf-mip6-ikev2-ipsec-08.txt, December 2006.
Appendix A. Proxy Mobile IPv6 interactions with AAA Infrastructure Appendix A. Proxy Mobile IPv6 interactions with AAA Infrastructure
Every mobile node that roams in a proxy Mobile IPv6 domain, would Every mobile node that roams in a proxy Mobile IPv6 domain, would
typically be identified by an identifier, MN-Identifier, and that typically be identified by an identifier, MN-Identifier, and that
identifier will have an associated policy profile that identifies the identifier will have an associated policy profile that identifies the
mobile node's home network prefix, permitted address configuration mobile node's home network prefix, permitted address configuration
modes, roaming policy and other parameters that are essential for modes, roaming policy and other parameters that are essential for
providing network-based mobility service. This information is providing network-based mobility service. This information is
typically configured in AAA. It is possible the home network prefix typically configured in AAA. It is possible the home network prefix
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mobile node will have access to this profile and these entities can mobile node will have access to this profile and these entities can
query this information using RADIUS/DIAMETER protocols. query this information using RADIUS/DIAMETER protocols.
Appendix B. Supporting Shared-Prefix Model using DHCPv6 Appendix B. Supporting Shared-Prefix Model using DHCPv6
For supporting shared-prefix model, i.e, if multiple mobile nodes are For supporting shared-prefix model, i.e, if multiple mobile nodes are
configured with a common IPv6 network prefix, as in Mobile IPv6 configured with a common IPv6 network prefix, as in Mobile IPv6
specification, it is possible to support that configuration under the specification, it is possible to support that configuration under the
following guidelines: following guidelines:
The mobile node is allowed to use statefull address configuration The mobile node is allowed to use stateful address configuration
using DHCPv6 for obtaining its address configuration. The mobile using DHCPv6 for obtaining its address configuration. The mobile
nodes is not allowed to use any of the stateless autoconfiguration nodes is not allowed to use any of the stateless autoconfiguration
techniques. The permitted address configuration models for the techniques. The permitted address configuration models for the
mobile node on the access link can be enforced by the mobile access mobile node on the access link can be enforced by the mobile access
gateway by setting the relevant flags in the Router Advertisements, gateway, by setting the relevant flags in the Router Advertisements,
as per ND Specification, [RFC-2461] as per ND Specification, [RFC-2461].
The Home Network Prefix Option that is sent by the mobile access The Home Network Prefix Option that is sent by the mobile access
gateway in the Proxy Binding Update message, must contain the 128-bit gateway in the Proxy Binding Update message, must contain the 128-bit
host address that the mobile node obtained via DHCPv6. host address that the mobile node obtained via DHCPv6.
Routing state at the mobile access gateway: Routing state at the mobile access gateway:
For all IPv6 traffic from the source MN-HoA::/128 to destination For all IPv6 traffic from the source MN-HoA::/128 to
0::/0, route via tunnel0, next-hop LMAA, where tunnel0 is the MAG to _ANY_DESTINATION_, route via tunnel0, next-hop LMAA, where tunnel0 is
LMA tunnel. the MAG to LMA tunnel.
Routing state at the local mobility anchor: Routing state at the local mobility anchor:
For all IPv6 traffic to destination MN-HoA::/128, route via tunnel0, For all IPv6 traffic to destination MN-HoA::/128, route via tunnel0,
next-hop Proxy-CoA, where tunnel0 is the LMA to MAG tunnel. next-hop Proxy-CoA, where tunnel0 is the LMA to MAG tunnel.
Authors' Addresses Authors' Addresses
Sri Gundavelli Sri Gundavelli
Cisco Cisco
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