draft-ietf-netlmm-proxymip6-01.txt   draft-ietf-netlmm-proxymip6-02.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: December 20, 2007 V. Devarapalli Expires: March 7, 2008 V. Devarapalli
Azaire Networks Azaire Networks
K. Chowdhury K. Chowdhury
Starent Networks Starent Networks
B. Patil B. Patil
Nokia Siemens Networks Nokia Siemens Networks
June 18, 2007 September 4, 2007
Proxy Mobile IPv6 Proxy Mobile IPv6
draft-ietf-netlmm-proxymip6-01.txt draft-ietf-netlmm-proxymip6-02.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
applicable patent or other IPR claims of which he or she is aware applicable patent or other IPR claims of which he or she is aware
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.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that Task Force (IETF), its areas, and its working groups. Note that
skipping to change at page 1, line 40 skipping to change at page 1, line 40
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
The list of current Internet-Drafts can be accessed at The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt. http://www.ietf.org/ietf/1id-abstracts.txt.
The list of Internet-Draft Shadow Directories can be accessed at The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html. http://www.ietf.org/shadow.html.
This Internet-Draft will expire on December 20, 2007. This Internet-Draft will expire on March 7, 2008.
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 This specification describes a network-based mobility management
specification [RFC3775]. In that model, the mobile node is protocol. It is called Proxy Mobile IPv6 and is based on Mobile IPv6
responsible for doing the signaling to its home agent to enable Protocol [RFC-3775]. This protocol enables mobility support to a
session continuity as it moves between subnets. The design principle host within a domain and without requiring its participation in any
in the case of host-based mobility relies on the mobile node being in mobility related signaling. The design principle in the case of
control of the mobility management. Network based mobility allows IP network-based mobility management protocol relies on the network
session continuity for a mobile node without its involvement in being in control of the mobility management.
mobility management. This specification describes a protocol
solution for network based mobility management that relies on Mobile
IPv6 signaling and reuse of home agent functionality. A proxy
mobility agent in the network which manages the mobility for a mobile
node is the reason for referring to this protocol as Proxy Mobile
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 . . . . . . . . . . . . . 7 3. Proxy Mobile IPv6 Protocol Overview . . . . . . . . . . . . . 8
4. Proxy Mobile IPv6 Protocol Security . . . . . . . . . . . . . 11 4. Proxy Mobile IPv6 Protocol Security . . . . . . . . . . . . . 11
4.1. Peer Authorization Database Entries . . . . . . . . . . . 11 4.1. Peer Authorization Database Entries . . . . . . . . . . . 12
4.2. Security Policy Database Entries . . . . . . . . . . . . . 12 4.2. Security Policy Database Entries . . . . . . . . . . . . . 13
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 Entry Data Structure . . . . . 14
5.2. Bi-Directional Tunnel Management . . . . . . . . . . . . . 14 5.2. Supported Home Network Prefix Models . . . . . . . . . . . 14
5.3. Routing Considerations . . . . . . . . . . . . . . . . . . 15 5.3. Signaling Considerations . . . . . . . . . . . . . . . . . 15
5.4. Local Mobility Anchor Address Discovery . . . . . . . . . 16 5.3.1. Processing Binding Registrations . . . . . . . . . . . 15
5.5. Sequence Number and Time-Stamps for Message Ordering . . . 16 5.4. Timestamp Option for Message Ordering . . . . . . . . . . 19
5.6. Route Optimizations Considerations . . . . . . . . . . . . 17 5.5. Routing Considerations . . . . . . . . . . . . . . . . . . 21
5.7. Mobile Prefix Discovery Considerations . . . . . . . . . . 18 5.5.1. Bi-Directional Tunnel Management . . . . . . . . . . . 21
5.8. Signaling Considerations . . . . . . . . . . . . . . . . . 18 5.5.2. Forwarding Considerations . . . . . . . . . . . . . . 22
5.8.1. Initial Proxy Binding Registration . . . . . . . . . . 18 5.6. Local Mobility Anchor Address Discovery . . . . . . . . . 23
5.8.2. Extending the binding lifetime . . . . . . . . . . . . 20 5.7. Mobile Prefix Discovery Considerations . . . . . . . . . . 23
5.8.3. De-registration of the binding . . . . . . . . . . . . 20 5.8. Route Optimizations Considerations . . . . . . . . . . . . 24
5.9. Local Mobility Anchor Operational Summary . . . . . . . . 20 6. Mobile Access Gateway Operation . . . . . . . . . . . . . . . 24
6. Mobile Access Gateway Operation . . . . . . . . . . . . . . . 21 6.1. Extensions to Binding Update List Entry Data Structure . . 25
6.1. Supported Access Link Types . . . . . . . . . . . . . . . 21 6.2. Mobile Node's Policy Profile . . . . . . . . . . . . . . . 26
6.2. Supported Home Network Prefix Models . . . . . . . . . . . 22 6.3. Supported Access Link Types . . . . . . . . . . . . . . . 26
6.3. Supported Address Configuration Models . . . . . . . . . . 22 6.4. Supported Address Configuration Models . . . . . . . . . . 26
6.4. Access Authentication & Mobile Node Identification . . . . 23 6.5. Access Authentication & Mobile Node Identification . . . . 27
6.5. Mobile Node's Policy Profile . . . . . . . . . . . . . . . 23 6.6. Acquiring Mobile Node's Identifier . . . . . . . . . . . . 27
6.6. Conceptual Data Structures . . . . . . . . . . . . . . . . 24 6.7. Home Network Emulation . . . . . . . . . . . . . . . . . . 28
6.7. Home Network Emulation . . . . . . . . . . . . . . . . . . 24 6.8. Link-Local and Global Address Uniqueness . . . . . . . . . 28
6.7.1. Home Network Prefix Renumbering . . . . . . . . . . . 25 6.9. Signaling Considerations . . . . . . . . . . . . . . . . . 30
6.8. Link-Local and Global Address Uniqueness . . . . . . . . . 26 6.10. Routing Considerations . . . . . . . . . . . . . . . . . . 32
6.9. Signaling Considerations . . . . . . . . . . . . . . . . . 27 6.10.1. Transport Network . . . . . . . . . . . . . . . . . . 32
6.9.1. Initial Attachment and binding registration . . . . . 27 6.10.2. Tunneling & Encapsulation Modes . . . . . . . . . . . 32
6.9.2. Extending the binding lifetime . . . . . . . . . . . . 28 6.10.3. Routing State . . . . . . . . . . . . . . . . . . . . 33
6.9.3. De-registration of the binding . . . . . . . . . . . . 28 6.10.4. Local Routing . . . . . . . . . . . . . . . . . . . . 34
6.10. Routing Considerations . . . . . . . . . . . . . . . . . . 28 6.10.5. Tunnel Management . . . . . . . . . . . . . . . . . . 35
6.10.1. Transport Network . . . . . . . . . . . . . . . . . . 29 6.10.6. Forwarding Rules . . . . . . . . . . . . . . . . . . . 35
6.10.2. Tunneling & Encapsulation Modes . . . . . . . . . . . 29 6.11. Interaction with DHCP Relay Agent . . . . . . . . . . . . 35
6.10.3. Routing State . . . . . . . . . . . . . . . . . . . . 30 6.12. Home Network Prefix Renumbering . . . . . . . . . . . . . 36
6.10.4. Local Routing . . . . . . . . . . . . . . . . . . . . 31 6.13. Mobile Node Detachment Detection and Resource Cleanup . . 36
6.10.5. Tunnel Management . . . . . . . . . . . . . . . . . . 31 6.14. Allowing network access to other IPv6 nodes . . . . . . . 37
6.10.6. Forwarding Rules . . . . . . . . . . . . . . . . . . . 31 7. Mobile Node Operation . . . . . . . . . . . . . . . . . . . . 37
6.11. Interaction with DHCP Relay Agent . . . . . . . . . . . . 32 7.1. Moving into a Proxy Mobile IPv6 Domain . . . . . . . . . . 38
6.12. Mobile Node Detachment Detection and Resource Cleanup . . 32 7.2. Roaming in the Proxy Mobile IPv6 Domain . . . . . . . . . 39
6.13. Allowing network access to other IPv6 nodes . . . . . . . 33 7.3. IPv6 Host Protocol Parameters . . . . . . . . . . . . . . 39
7. Mobile Node Operation . . . . . . . . . . . . . . . . . . . . 34 8. Message Formats . . . . . . . . . . . . . . . . . . . . . . . 40
7.1. Booting up in a Proxy Mobile IPv6 Domain . . . . . . . . . 34 8.1. Proxy Binding Update . . . . . . . . . . . . . . . . . . . 41
7.2. Roaming in the Proxy Mobile IPv6 Network . . . . . . . . . 35 8.2. Proxy Binding Acknowledgment . . . . . . . . . . . . . . . 42
7.3. IPv6 Host Protocol Parameters . . . . . . . . . . . . . . 36 8.3. Home Network Prefix Option . . . . . . . . . . . . . . . . 42
8. Message Formats . . . . . . . . . . . . . . . . . . . . . . . 37 8.4. Link-local Address Option . . . . . . . . . . . . . . . . 43
8.1. Proxy Binding Update . . . . . . . . . . . . . . . . . . . 37 8.5. Timestamp Option . . . . . . . . . . . . . . . . . . . . . 44
8.2. Proxy Binding Acknowledgment . . . . . . . . . . . . . . . 38 8.6. Status Values . . . . . . . . . . . . . . . . . . . . . . 45
8.3. Home Network Prefix Option . . . . . . . . . . . . . . . . 39 9. Protocol Configuration Variables . . . . . . . . . . . . . . . 46
8.4. Time Stamp Option . . . . . . . . . . . . . . . . . . . . 40 10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 47
8.5. Status Codes . . . . . . . . . . . . . . . . . . . . . . . 41 11. Security Considerations . . . . . . . . . . . . . . . . . . . 47
9. Protocol Configuration Variables . . . . . . . . . . . . . . . 42 12. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 48
10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 42 13. References . . . . . . . . . . . . . . . . . . . . . . . . . . 49
11. Security Considerations . . . . . . . . . . . . . . . . . . . 42 13.1. Normative References . . . . . . . . . . . . . . . . . . . 49
12. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 44 13.2. Informative References . . . . . . . . . . . . . . . . . . 50
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 . . . . . . . . . . . . . . . . . . . 46 Infrastructure . . . . . . . . . . . . . . . . . . . 51
Appendix B. Supporting Shared-Prefix Model using DHCPv6 . . . . . 46 Appendix B. Supporting Shared-Prefix Model using DHCPv6 . . . . . 51
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 47 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 52
Intellectual Property and Copyright Statements . . . . . . . . . . 49 Intellectual Property and Copyright Statements . . . . . . . . . . 54
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 mobile node and home agent enables the creation Signaling between the mobile node and home agent enables the creation
and maintenance of a binding between the mobile node's home address and maintenance of a binding between the mobile node's home address
and care-of-address. Mobile IPv6 has been designed to be an integral and care-of-address. Mobile IPv6 has been designed to be an integral
part of the IPv6 stack in a host. However there exist IPv6 stacks part of the IPv6 stack in a host. However there exist IPv6 stacks
today that do not have Mobile IPv6 functionality and there would today that do not have Mobile IPv6 functionality and there would
skipping to change at page 4, line 26 skipping to change at page 4, line 26
irrespective of the presence or absence of mobile IPv6 functionality irrespective of the presence or absence of mobile IPv6 functionality
in the IPv6 stack. 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 mobility agent in the required for mobility management. The proxy mobility agent in the
network performs the signaling and does the mobility management on network performs the signaling and does the mobility management on
behalf of the mobile node. Because of the use and extension of behalf of the mobile node. Because of the use and extension of
Mobile IPv6 signaling and home agent functionality, it is referred to Mobile IPv6 signaling and home agent functionality, this protocol is
as Proxy Mobile IPv6 (PMIP6) in the context of this document. referred to as Proxy Mobile IPv6 (PMIPv6).
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 Proxy Mobile IPv6 protocol would be supported by enabling Proxy Mobile IPv6 protocol
functionality in the network. The advantages of developing a network functionality in the network. The advantages of developing a network
based mobility 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
skipping to change at page 6, line 45 skipping to change at page 6, line 45
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, as defined in [ID-IPV4-PMIP6]. used, as specified in [ID-IPV4-PMIP6].
Mobile Node's Home Address (MN-HoA) Mobile Node's Home Address (MN-HoA)
MN-HoA is the home address of a mobile node in a Proxy Mobile IPv6 MN-HoA is the home address of a mobile node in a Proxy Mobile IPv6
domain. It is an address obtained by the mobile node in that domain. It is an address from its home network prefix obtained by
domain. The mobile node can continue to use this address as long a mobile node in a Proxy Mobile IPv6 domain. The mobile node can
as it is attached to the network that is in the scope of that continue to use this address as long as it is attached to the
Proxy Mobile IPv6 domain. network that is in the scope of that Proxy Mobile IPv6 domain.
Mobile Node's Home Network Prefix (MN-HNP) Mobile Node's Home Network Prefix (MN-HNP)
This is the on-link IPv6 prefix that the mobile node always sees This is the on-link IPv6 prefix that is always present in the
in the Proxy Mobile IPv6 domain. The home network prefix is Router Advertisements that the mobile node receives on any of the
topologically anchored at the mobile node's local mobility anchor. access links in that Proxy Mobile IPv6 domain. This home network
The mobile node configures its interface with an address from this prefix is topologically anchored at the mobile node's local
prefix. mobility anchor. 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 Identifier (MN-Identifier) Mobile Node Identifier (MN-Identifier)
The identity of the mobile node that is presented to the network The identity of a mobile node in the Proxy Mobile IPv6 domain.
as part of the access authentication. This is typically an This is the stable identifier of a mobile node that the mobility
identifier such as Mobile Node NAI [RFC-4283], or any other type entities in a Proxy Mobile IPv6 domain can always acquire and
of identifier which may be specific to the access technology. using which can predictably identify a mobile node. This is
typically an identifier such as Mobile Node NAI [RFC-4282].
Proxy Binding Update (PBU) Proxy Binding Update (PBU)
A signaling message sent by the mobile access gateway to a mobile A request message sent by a 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-HNP 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 and is based on Mobile IPv6 protocol. It is called Proxy Mobile IPv6 and is based on Mobile IPv6
[RFC-3775]. This protocol is for providing network-based mobility [RFC-3775].
management support to a mobile node, within a restricted and
topologically localized portion of the network and with out requiring
the participation of the mobile node in any mobility related
signaling.
Every mobile node that roams in a Proxy Mobile IPv6 domain, would Proxy Mobile IPv6 protocol is intended for providing network-based
typically be identified by an identifier, MN-Identifier, and using mobility management support to a mobile node, without requiring the
that identifier the mobile node's policy profile can be obtained from participation of the mobile node in any mobility related signaling.
the policy store. The policy profile typically contains the The mobility entities in the network will track the mobile node's
provisioned network-based mobility service characteristics and other movements and will initiate the mobility signaling and setup the
related parameters such as the mobile node's Identifier, local required routing state.
mobility anchor address, permitted address configuration modes,
roaming policy and other parameters that are essential for providing
the network based mobility service.
Once a mobile node enters its Proxy Mobile IPv6 domain and performs The core functional entities in the NETLMM infrastructure are the
access authentication, the network will ensure that the mobile node Local Mobility Anchor and the Mobile Access Gateway. The local
is always on its home network and can obtain its home address on any mobility is responsible for maintaining the mobile node's
access link using any of the address configuration procedures. In reachability state and is the topological anchor point for the mobile
other words, there is a home network prefix that is assigned to a node's home network prefix. While the mobile access gateway is the
mobile node and conceptually that address always follows the mobile entity that performs the mobility management on behalf of a mobile
node, where ever it roams within that Proxy Mobile IPv6 domain. From node and it resides on the access link where the mobile node is
the perspective of the mobile node, the entire Proxy Mobile IPv6 anchored. The mobile access gateway is responsible for detecting the
domain appears as its home link or a single link. mobile node's movements on its access link and for sending binding
registrations to the mobile node's local mobility anchor.
+----+ +----+ +----+ +----+
|LMA1| |LMA2| |LMA1| |LMA2|
+----+ +----+ +----+ +----+
LMAA1 -> | | <-- LMAA2 LMAA1 -> | | <-- LMAA2
| | | |
\\ //\\ \\ //\\
\\ // \\ \\ // \\
\\ // \\ \\ // \\
+---\\------------- //------\\----+ +---\\------------- //------\\----+
skipping to change at page 9, line 27 skipping to change at page 9, line 4
\\ // \\ \\ // \\
\\ // \\ \\ // \\
\\ // \\ \\ // \\
Proxy-CoA1--> | | <-- Proxy-CoA2 Proxy-CoA1--> | | <-- Proxy-CoA2
+----+ +----+ +----+ +----+
|MAG1|-----[MN2] |MAG2| |MAG1|-----[MN2] |MAG2|
+----+ | +----+ +----+ | +----+
| | | | | |
MN-HoA1 --> | MN-HoA2 | <-- MN-HoA3 MN-HoA1 --> | MN-HoA2 | <-- MN-HoA3
[MN1] [MN3] [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 Once a mobile node enters a Proxy Mobile IPv6 domain and attaches to
access gateway. It is a function that is on the access link where an access network, the mobile access gateway on that access network
the mobile node is anchored and does the mobility related signaling after identifying the mobile node and acquiring its identifier, will
on its behalf. From the perspective of the local mobility anchor, determine if the mobile node is authorized for network-based mobility
the mobile access gateway is a special element in the network that is management service.
authorized to send Mobile IPv6 signaling messages on behalf of other
mobile nodes.
When the mobile node attaches to an access link connected to the If the network determines that the network-based mobility management
mobile access gateway, the mobile node presents its identity, MN- service needs to be offered to that mobile node, the network will
Identifier, as part of the access authentication procedure. After a ensure that the mobile node using any of the address configuration
successful access authentication, the mobile access gateway obtains mechanisms permitted by the network, will be able to obtain an
the mobile node's profile from the policy store. The mobile access address from its home network prefix and move anywhere in that proxy
gateway would have all the required information for it to emulate the mobile IPv6 domain. From the perspective of the mobile node, the
mobile node's home network on the access link. It sends Router entire proxy mobile IPv6 domain appears as a single link, the network
Advertisement messages to the mobile node on the access link ensures that the mobile node believes it is always on the same link
advertising the mobile node's home network prefix as the hosted on- where it obtained its initial address configuration, even after
link-prefix. changing its point of attachment in that network.
The mobile node on receiving these Router Advertisement messages on The mobile node may be operating in an IPv4-only mode, IPv6-only mode
the access link will attempt to configure its interface either using or in dual IPv4/IPv6 mode. Based on what is enabled in the network
stateful or stateless address configuration modes, based on modes for that mobile node, the mobile node will be able to obtain an IPv4,
that are permitted on that access link. At the end of a successful IPv6 or dual IPv4/IPv6 addresses and move any where in that Proxy
address configuration procedure, the mobile node would have obtained Mobile IPv6 domain. However, the specific details related to the
an address from its home network prefix. If the mobile node is IPv4 IPv4 addressing or IPv4 transport support is specified in the
capable and if network offers IPv4 network mobility for the mobile companion document [ID-IPV4-PMIP6].
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 +-----+ +-----+ +-----+
dual-mode and based on the services enabled for that mobile, the | MN | | MAG | | LMA |
mobility is enabled only for those address types. Also, the network +-----+ +-----+ +-----+
between the local mobility anchor and the mobile access gateway can | | |
be either IPv4, IPv6 or a private IPv4 with NAT translation devices. MN Attached | |
| | |
| MN Attached Event |
| (Acquire MN-Id and Profile) |
| | |
| |----- PBU ----------->|
| | |
| | Accept PBU
| | (Allocate MN-HNP, Setup BCE and Tunnel)
| | |
| |<--------- PBA -------|
| | |
| Accept PBA |
| (Setup Tunnel and Routing) |
| | |
| |==== Bi-Dir Tunnel ===|
| | |
|--- Rtr Sol --------->| |
| | |
|<------- Rtr Adv -----| |
| | |
IP Address | |
Configuration | |
| | |
Figure 2: Mobile Node Attachment - Signaling Call Flow
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. Upon
message will have the mobile node's NAI identifier option and other accepting this Proxy Binding Update message, the local mobility
required options. Upon accepting the Proxy Binding Update message, anchor sends a Proxy Binding Acknowledgment message including the
the local mobility anchor sends a Proxy Binding Acknowledgment mobile node's home network prefix. It also creates the binding cache
message including the mobile node's home network prefix option. It entry and establishes a bi-directional tunnel to the mobile access
also sets up a route for the mobile node's home network prefix over gateway.
the tunnel to the mobile access gateway.
The mobile access gateway on receiving this Proxy Binding The mobile access gateway on receiving the Proxy Binding
Acknowledgment message sets up a bi-directional tunnel to the local Acknowledgment message sets up a bi-directional tunnel to the local
mobility anchor and adds a default route over the tunnel to the local mobility anchor and sets up the data path for the mobile node's
mobility anchor. All traffic from the mobile node gets routed to its traffic. At this point the mobile access gateway will have all the
local mobility anchor through the bi-directional tunnel. required information for emulating the mobile node's home link. It
sends Router Advertisement messages to the mobile node on the access
link advertising the mobile node's home network prefix as the hosted
on-link-prefix.
At this point, the mobile node has a valid address from its home The mobile node on receiving these Router Advertisement messages on
network prefix, at the current point of attachment. The serving the access link will attempt to configure its interface either using
mobile access gateway and the local mobility anchor also have proper stateful or stateless address configuration modes, based on the modes
routing states for handling the traffic sent to and from the mobile that are permitted on that access link. At the end of a successful
node using an address from its home network prefix. address configuration procedure, the mobile node will end up with an
address from its home network prefix.
Once the address configuration is complete, the mobile node has a
valid address from its home network prefix, at the current point of
attachment. The serving mobile access gateway and the local mobility
anchor also have proper routing states for handling the traffic sent
to and from the mobile 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, receives any packet that is sent mobile node's home network prefix, receives any packets that are sent
by any 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 these received packets to the mobile access gateway through
bi-directional tunnel. The mobile access gateway on other end of the the bi-directional tunnel. The mobile access gateway on other end of
tunnel, after receiving the packet, removes the outer header and the tunnel, after receiving the packet, removes the outer header and
forwards the 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 its local mobility anchor through the bi- forwards the packet to its local mobility anchor through the bi-
directional tunnel. The local mobility anchor on the other end of directional tunnel. The local mobility anchor on the other end of
the tunnel, after receiving the packet removes the outer header and the tunnel, after receiving the packet removes the outer header and
routes the packet to the destination. routes the packet to the destination.
After obtaining the address configuration, if the mobile node changes
4. Proxy Mobile IPv6 Protocol Security 4. Proxy Mobile IPv6 Protocol Security
The signaling messages, Proxy Binding Update and Proxy Binding The mobile access gateway and the local mobility anchor MUST support
Acknowledgement, exchanged between the mobile access gateway and the and SHOULD use IPsec to protect the integrity and authenticity of the
local mobility anchor are protected using IPsec and using the signaling messages. The signaling messages, Proxy Binding Update and
established security association between them. The security Proxy Binding Acknowledgement, exchanged between the mobile access
association of the specific mobile node for which the signaling gateway and the local mobility anchor SHOULD be protected using IPsec
message is initiated is not required for protecting these messages. [RFC-4301] and using the established security association between
them. The security association of the specific mobile node for which
the signaling message is initiated is not required for protecting
these messages.
ESP in transport mode with mandatory integrity protection is used for IPsec ESP [RFC-4303] in transport mode with mandatory integrity
protecting the signaling messages. Confidentiality protection is not protection SHOULD be used for protecting the signaling messages.
required. Confidentiality protection of these messages is not required.
IKEv2 is used to setup security associations between the mobile IKEv2 [RFC-4306] SHOULD be used to setup security associations
access gateway and the local mobility anchor to protect the Proxy between the mobile access gateway and the local mobility anchor to
Binding Update and Proxy Binding Acknowledgment messages. The mobile protect the Proxy Binding Update and Proxy Binding Acknowledgment
access gateway and the local mobility anchor can use any of the messages. The mobile access gateway and the local mobility anchor
authentication mechanisms, as specified in IKEv2, for mutual can use any of the authentication mechanisms, as specified in IKEv2,
authentication. for mutual authentication.
Mobile IPv6 specification requires the home agent to prevent a mobile Mobile IPv6 specification [RFC-3775] requires the home agent to
node from creating security associations or creating binding cache prevent a mobile node from creating security associations or creating
entries for another mobile node's home address. In the protocol binding cache entries for another mobile node's home address. In the
described in this document, the mobile node is not involved in protocol described in this document, the mobile node is not involved
creating security associations for protecting the signaling messages in creating security associations for protecting the signaling
or sending binding updates. Therefore, this is not a concern. messages or sending binding updates. Therefore, this is not a
However, the local mobility anchor MUST allow only authorized mobile concern. However, the local mobility anchor MUST allow only
access gateways to create binding cache entries on behalf of the authorized mobile access gateways to create binding cache entries on
mobile nodes. The actual mechanism by which the local mobility behalf of the mobile nodes. The actual mechanism by which the local
anchor verifies if a specific mobile access gateway is authorized to mobility anchor verifies if a specific mobile access gateway is
send Proxy Binding Updates on behalf of a mobile node is outside the authorized to send Proxy Binding Updates on behalf of a mobile node
scope of this document. One possible way this could be achieved is is outside the scope of this document. One possible way this could
sending a query to the policy store such as by using AAA be achieved is by sending a query to the policy store, such as AAA.
infrastructure.
4.1. Peer Authorization Database Entries 4.1. Peer Authorization Database Entries
The following describes PAD entries on the mobile access gateway and This section 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 any 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.
mobile access gateway PAD: mobile access gateway PAD:
- IF remote_identity = lma_identity_1 - IF remote_identity = lma_identity_1
Then authenticate (shared secret/certificate/EAP) Then authenticate (shared secret/certificate/EAP)
and authorize CHILD_SA for remote address lma_addres_1 and authorize CHILD_SA for remote address lma_addres_1
local mobility anchor PAD: local mobility anchor PAD:
- IF remote_identity = mag_identity_1 - IF remote_identity = mag_identity_1
Then authenticate (shared secret/certificate/EAP) Then authenticate (shared secret/certificate/EAP)
and authorize CHILD_SAs for remote address mag_address_1 and authorize CHILD_SAs for remote address mag_address_1
The list of authentication mechanisms in the above examples is not The list of authentication mechanisms in the above examples is not
exhaustive. There could be other credentials used for authentication exhaustive. There could be other credentials used for authentication
stored in the PAD. stored in the PAD.
4.2. Security Policy Database Entries 4.2. Security Policy Database Entries
The following describes the security policy entries on the mobile This section describes the security policy entries on the mobile
access gateway and the local mobility anchor required to protect the access gateway and the local mobility anchor required to protect the
Proxy Mobile IPv6 signaling messages. The SPD entries are only Proxy Mobile IPv6 signaling messages. The SPD entries are only
example configurations. A particular mobile access gateway or a example configurations. A particular mobile access gateway or a
local mobility anchor implementation could configure different SPD local mobility anchor implementation could configure different SPD
entries as long as they provide the required security. entries as long as they provide the required security.
In the examples shown below, the identity of the mobile access In the examples shown below, the identity of the mobile access
gateway is assumed to be mag_1, the address of the mobile access gateway is assumed to be mag_1, the address of the mobile access
gateway is assumed to be mag_address_1, and the address of the local gateway is assumed to be mag_address_1, and the address of the local
mobility anchor is assumed to be lma_address_1. mobility anchor is assumed to be lma_address_1.
skipping to change at page 13, line 7 skipping to change at page 13, line 39
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 specified in this For supporting the Proxy Mobile IPv6 protocol specified in this
document, the Mobile IPv6 home agent entity, defined in Mobile IPv6 document, the home agent function, specified in [RFC-3775] requires
specification [RFC-3775], needs some enhancements. The local certain functional modifications and enhancements. The home agent
mobility anchor is an entity that has the functional capabilities of with these modifications and enhanced capabilities for supporting
a home agent and with the additional required capabilities for Proxy Mobile IPv6 protocol is referred to as the local mobility
supporting Proxy Mobile IPv6 protocol as defined in this anchor.
specification. This section describes the operational details of the
local mobility anchor.
The base Mobile IPv6 specification [RFC-3775], defines home agent and
the mobile node as the two functional entities. The Proxy Mobile
IPv6 scheme introduces a new entity, the mobile access gateway. This
is the entity that will participate in the mobility related
signaling. From the perspective of the local mobility anchor, the
mobile access gateway is a special element in the network that has
the privileges to send mobility related signaling messages on behalf
of the mobile node. Typically, the local mobility anchor is
provisioned with the list of mobile access gateways authorized to
send proxy registrations.
When the local mobility anchor receives a Proxy Binding Update The section describes the operational details of the local mobility
message from a mobile access gateway, the message is protected using anchor.
the IPSec Security Association established between the local mobility
anchor and the mobile access gateway. The local mobility anchor can
distinguish between a Proxy Binding Update message received from a
mobile access gateway from a Binding Update message received directly
from a mobile node. This distinction is important for using the
right security association for validating the Binding Update and this
is achieved by relaxing the MUST requirement for having the Home
Address Option presence in Destination Options header and by
introducing a new flag in the Binding Update message. The local
mobility anchor as a traditional IPSec peer can use the SPI in the
IPSec header [RFC-4306] of the received packet for locating the
correct security association and for processing the Proxy Binding
Update message in the context of the Proxy Mobile IPv6 scheme.
For protocol simplicity, the current specification supports the Per- 5.1. Extensions to Binding Cache Entry Data Structure
MN-Prefix addressing model. In this addressing model, each mobile
node is allocated an exclusively unique home network prefix. The
local mobility anchor in this model is just a topological anchor
point for that prefix and the prefix is physically hosted on the
access link where the mobile node is attached. The local mobility
anchor is not required to perform any proxy ND operations [RFC-2461]
for defending the mobile node's home address on the home link.
However, the local mobility anchor is required to manage the binding
cache entry of the mobile node for managing the mobility session and
also the routing state for creating a proper route path for traffic
to/from the mobile node.
5.1. Extensions to Binding Cache Conceptual Data Structure Every local mobility anchor MUST maintain a Binding Cache Entry for
each currently registered mobile node. Binding Cache Entry is a
conceptual data structure, described in Section 9.1 [RFC-3775].
The local mobility anchor maintains a Binding Cache entry for each For supporting this specification, the Binding Cache Entry data
currently registered mobile node. Binding Cache is a conceptual data structure needs to be extended with the following additional fields.
structure, described in Section 9.1 of [RFC-3775]. For supporting
this specification, the conceptual Binding Cache entry needs to be
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 created due to the
mobile node. registrations directly sent by the mobile node.
o The identifier of the mobile node, MN-Identifier. This MN-
Identifier is obtained from the NAI Option present in the Proxy
Binding Update request [RFC-4285].
o A flag indicating whether or not the Binding Cache entry has a
home address that is on virtual interface. This flag is enabled,
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
virtual interface, the home agent is not required to function as a
Neighbor Discovery proxy for 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 interface id of the bi-directional tunnel between the local
mobility anchor and the mobile access gateway used for sending and
receiving the mobile node's traffic.
5.2. Bi-Directional Tunnel Management
The bi-directional tunnel between the local mobility anchor and the o The identifier of the registered mobile node, MN-Identifier. This
mobile access gateway is used for routing the traffic to and from the identifier is obtained from the NAI Option [RFC-4283] present in
mobile node. The tunnel hides the topology and enables a mobile node the received Proxy Binding Update request.
to use an IP address that is topologically anchored at the local
mobility anchor, from any attached access link in that proxy mobile
IPv6 domain. The base Mobile IPv6 specification [RFC-3775], does use
the tunneling scheme for routing traffic to and from the mobile that
is using its home address. However, there are subtle differences in
the way Proxy Mobile IPv6 uses the tunneling scheme.
As in Mobile IPv4 [RFC-3344], the tunnel between the local mobility o The Link-local address of the mobile node on the interface
anchor and the mobile access gateway is typically a shared tunnel and attached to the access link. This is obtained from the Link-local
can be used for routing traffic streams for different mobile nodes Address option, present in the Proxy Binding Update request.
attached to the same mobile access gateway. This specification
extends that 1:1 relation between a tunnel and a binding cache entry
to 1:m relation, reflecting the shared nature of the tunnel.
The tunnel is creating after accepting a Proxy Binding Update message o The IPv6 home network prefix of the registered mobile node. The
for a mobile node from a mobile access gateway. The created tunnel home network prefix of the mobile node may have been statically
may be shared with other mobile nodes attached to the same mobile configured in the mobile node's policy profile, or, it may have
access gateway and with the local mobility anchor having a binding been dynamically allocated by the local mobility anchor. The IPv6
cache entry for those mobile nodes. Some implementations may prefer home network prefix also includes the corresponding prefix length.
to use static tunnels as supposed to creating and tearing them down
on a need basis.
The one end point of the tunnel is the address configured on the o The interface identifier of the bi-directional tunnel established
interface of the local mobility anchor, LMAA. The other end point of between the local mobility anchor and the mobile access gateway
the tunnel is the address configured on the interface of the mobile where the mobile node is currently anchored. The tunnel interface
access gateway, Proxy-CoA. The details related to the supported identifier is acquired during the tunnel creation.
encapsulation modes and transport protocols is covered in detail in
Section 6.10.2.
Implementations typically use a software timer for managing the o The 64-bit timestamp value of the most recently accepted Proxy
tunnel lifetime and a counter for keeping a count of all the mobiles Binding Update request sent for this mobile node. This is
that are sharing the tunnel. The timer value will be set to the obtained from the Timestamp option, present in the request.
accepted binding life-time and will be updated after each periodic
registrations for extending the lifetime. If the tunnel is shared
for multiple mobile node's traffic, the tunnel lifetime will be set
to the highest binding life time across all the binding life time
that is granted for all the mobiles sharing that tunnel.
5.3. Routing Considerations 5.2. Supported Home Network Prefix Models
This section describes how the data traffic to/from the mobile node This specification supports Per-MN-Prefix model and does not support
is handled at the local mobility anchor. Shared-Prefix model. As per the Per-MN-Prefix model, there will be
an unique home network prefix assigned to each mobile node and no
other node shares an address from that prefix.
When a local mobility anchor is serving a mobile node, it MUST The mobile node's home network prefix is always hosted on the access
attempt to intercept packets that are sent to any address that is in link where the mobile node is anchored. Conceptually, the entire
the mobile node's home network prefix address range. The local home network prefix follows the mobile node as it moves within the
mobility anchor MUST advertise a connected route in to the Routing Proxy Mobile IPv6 domain. The local mobility anchor is not required
Infrastructure for that mobile node's home network prefix or for an to perform any proxy ND operations [RFC-2461] for defending the
aggregated prefix with a larger scope. This essentially enables mobile node's home address on the home link. However, from the
routers in the IPv6 network to detect the local mobility anchor as routing perspective, the home network prefix is topologically
the last-hop router for that prefix. anchored on the local mobility anchor and is the gateway to that home
network prefix.
When forwarding any packets that have the destination address 5.3. Signaling Considerations
matching the mobile node's home network prefix, the local mobility
anchor MUST encapsulate the packet with the outer IPv6 header, as
specified in Generic Packet Tunneling in IPv6 specification [RFC-
2473]. If the negotiated encapsulation header is either IPv6-over-
IPv4 or IPv6-over-IPv4-UDP, as specified in the companion document,
IPv4 support for Proxy Mobile IP6 [ID-Pv4-PMIP6], the packet must be
encapsulated and routed as specified in that specification.
All the reverse tunneled packets that the local mobility anchor 5.3.1. Processing Binding Registrations
receives from the tunnel, after removing the outer header MUST be
routed to the destination specified in the inner packet header.
These routed packets will have the source address field set to the
address from the mobile node's home network prefix.
5.4. Local Mobility Anchor Address Discovery Upon receiving a Proxy Binding Update request from a mobile access
gateway on behalf of a mobile node, the local mobility anchor MUST
process the request as defined in Section 10.3 [RFC-3775], with one
exception that this request is a proxy binding registration request
and hence the following additional considerations must be applied.
Dynamic Home Agent Address Discovery, as explained in Section 10.5 of o The local mobility anchor MUST observe the rules described in
[RFC-3775], allows a mobile node to discover all the home agents on Section 9.2 [RFC-3775] when processing Mobility Headers in the
its home link by sending an ICMP Home Agent Address Discovery Request received Proxy Binding Update request.
message to the Mobile IPv6 Home-Agents anycast address, derived from
its home network prefix.
In Proxy Mobile IPv6, the address of the local mobility anchor o The local mobility anchor MUST identify the mobile node from the
configured to serve a mobile node can be discovered by the mobility identifier present in the NAI option of the Proxy Binding Update
entities in one or more ways. This MAY be a configured entry in the request. If the NAI option is not present in the Proxy Binding
mobile node's policy profile, or it MAY be obtained through Update request, the local mobility anchor MUST reject the request
mechanisms outside the scope of this document. It is important to and send a Proxy Binding Acknowledgement message with Status field
note that there is little value in using DHAAD message in the current set to MISSING_MN_IDENTIFIER_OPTION (Missing mobile node
form for discovering the local mobility anchor address dynamically. identifier).
As a mobile node moves from one mobile access gateway to the another,
the serving mobile access gateway will not predictably be able to
locate the serving local mobility anchor for that mobile that has its
binding cache entry for the mobile node. Hence, this specification
does not support Dynamic Home Agent Address Discovery protocol.
5.5. Sequence Number and Time-Stamps for Message Ordering o If the local mobility anchor cannot identify the mobile node, from
the NAI option present in the request, it MUST reject the Proxy
Binding Update request and send a Proxy Binding Acknowledgement
message with Status field set to 133 (Not home agent for this
mobile node).
Mobile IPv6 [RFC-3775] uses the Sequence Number field in registration o If the local mobility anchor determines that the mobile node is
messages as a way to ensure the correct packet ordering. The local not authorized for network-based mobility management service, it
mobility anchor and the mobile node are required to manage this MUST reject the request and send a Proxy Binding Acknowledgement
counter over the lifetime of a binding. message with Status field set to PROXY_REG_NOT_ENABLED (Proxy
Registration not enabled).
In Proxy Mobile IPv6, the Proxy Binding Update messages that the o The local mobility anchor MUST ignore the check, specified in
local mobility anchor receives on behalf of a specific mobile node Section 10.3.1 [RFC-3775], related to the presence of Home Address
may not be from the same mobile access gateway as the previously destination option in the Proxy Binding Update request.
received message. It creates certain ambiguity and the local
mobility anchor will not be predictably order the messages. This
could lead to the local mobility anchor processing an older message
from a mobile access gateway where the mobile node was previously
attached, while ignoring the latest binding update message.
In the Proxy Mobile IPv6, the ordering of packets has to be o The local mobility anchor MUST authenticate the Proxy Binding
established across packets received from multiple senders. The Update request as described in Section 4.0. It MUST use the SPI
sequence number scheme as specified in [RFC-3775] will not be in the IPSec header [RFC-4306] of the received packet for locating
sufficient. A global scale, such as a time stamp, can be used to the security association needed for processing the Proxy Binding
ensure the correct ordering of the packets. This document proposes Update request.
the use of a Time Stamp Option, specified in Section 8.4, in all
Proxy Binding Update messages sent by mobile access gateways. By
leveraging the NTP [RFC-1305] service, all the entities in Proxy
Mobile IPv6 domain will be able to synchronize their respective
clocks. Having a time stamp option in Proxy Binding Update messages
will enable the local mobility anchor to predictably identify the
latest message from a list of messages delivered in an out-of-order
fashion.
The Proxy Mobile IPv6 model, defined in this document requires the o The local mobility anchor MUST apply the required policy checks,
Proxy Binding Update messages sent by the mobile access gateway to as explained in Section 4.0, to verify the sender is a trusted
have the Time Stamp option. The local mobility anchor processing a mobile access gateway, authorized to send proxy binding
proxy registration MUST ignore the sequence number field and MUST the registration requests on behalf of this mobile node.
value from the Time Stamp option to establish ordering of the
received Binding Update messages. If the local mobility anchor
receives a Proxy Binding Update message with an invalid Time Stamp
Option, the Proxy Binding Update MUST be rejected and a Proxy Binding
Acknowledgement MUST be returned in which the Status field is set to
148 (invalid time stamp option).
In the absence of Time Stamp option in the Proxy Binding Update, the o If the local mobility anchor determines that the requesting node
entities can fall back to Sequence Number scheme for message is not authorized to send proxy binding registration requests, it
ordering, as defined in RFC-3775. However, the specifics on how MUST reject the Proxy Binding Update request and send a Proxy
different mobile access gateways synchronize the sequence number is Binding Acknowledgement message with Status field set to
outside the scope of this document. MAG_NOT_AUTHORIZED_FOR_PROXY_REG (Not authorized to send proxy
registrations).
When using the Time Stamp Option, the local mobility anchor or the o If the Home Network Prefix option is not present in the Proxy
mobile access gateway MUST set the timestamp field to a 64-bit value Binding Update request, the local mobility anchor MUST reject the
formatted as specified by the Network Time Protocol [RFC-1305]. The Proxy Binding Update request and send a Proxy Binding
low-order 32 bits of the NTP format represent fractional seconds, and Acknowledgement message with Status field set to 129
those bits which are not available from a time source SHOULD be (Administratively Prohibited).
generated from a good source of randomness.
5.6. Route Optimizations Considerations o The local mobility anchor MUST apply the considerations specified
in Section 5.4, for processing the Sequence Number field and the
Timestamp option, in the Proxy Binding Update request.
Mobile IPv6 route optimization, as defined in [RFC-3775], enables a o The local mobility anchor MUST use the identifier in the NAI
mobile node to communicate with a corresponding node directly using option present in the Proxy Binding Update request for performing
its care-of address and further the Return Routability procedure the Binding Cache entry existence test. If the entry does not
enables the corresponding node to have reasonable trust that the exist, the local mobility MUST consider this request as an initial
mobile node owns both the home address and care-of address. binding registration request.
In the Proxy Mobile IPv6 model, the mobile is not involved in any Initial Binding Registration:
mobility related signaling and also it does not operate in the dual-
address mode. Hence, the return routability procedure as defined in
RFC-3775 is not applicable for the proxy model.
5.7. Mobile Prefix Discovery Considerations o If the Home Network Prefix option present in the Proxy Binding
Update request 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 prefix value. The specific details on
how the local mobility anchor allocates the home network prefix is
outside the scope of this document. The local mobility anchor
MUST ensure the allocated prefix is not in use by any other mobile
node.
The ICMP Mobile Prefix Advertisement message, described in Section o If the local mobility anchor is unable to allocate a home network
6.8 and Section 11.4.3 of [RFC-3775], allows a home agent to send a prefix for the mobile node, it MUST reject the request and send a
Mobile Prefix Advertisement to the mobile node. Proxy Binding Acknowledgement message with Status field set to 130
(Insufficient resources).
In Proxy Mobile IPv6, the mobile node's home network prefix is hosted o If the Home Network Prefix option present in the request has a
on the access link connected to the mobile access gateway. but specific prefix hint, the local mobility anchor before accepting
topologically anchored on the local mobility anchor. Since, there is that request, MUST ensure the prefix is owned by the local
no physical home-link for the mobile node's home network prefix on mobility anchor and further the mobile node is authorized to use
the local mobility anchor and as the mobile is always on the link that prefix. If the mobile node is not authorized to use that
where the prefix is hosted, any prefix change messages can just be prefix, the local mobility anchor MUST reject the request and send
advertised by the mobile access gateway on the access link and thus a Proxy Binding Acknowledgement message with Status field set to
there is no applicability of this message for Proxy Mobile IPv6. NOT_AUTHORIZED_FOR_HOME_NETWORK_PREFIX (Mobile node not authorized
This specification does not use Mobile Prefix Discovery. to use that prefix).
5.8. Signaling Considerations o Upon accepting the request, the local mobility anchor MUST create
a Binding Cache entry for the mobile node. It must set the fields
in the Binding Cache entry to the accepted value for that binding.
If there is a Link-local Address option present in the request,
the address must be copied to the link-local address field in the
Binding Cache entry.
5.8.1. Initial Proxy Binding Registration o Upon accepting the Proxy Binding Update request, the local
mobility anchor MUST establish a tunnel to the mobile access
gateway, as described in [RFC-2473]. Considerations from Section
5.5 must be applied.
Upon receiving a Proxy Binding Update message from a mobile access Binding Re-Registration:
gateway on behalf of mobile node, the local mobility anchor MUST
process the request as defined in Section 10, of the base 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.
The local mobility anchor MUST apply the required policy checks, as o If the requesting prefix in the Home Network Prefix option is a
explained in Section 4.0 of this document to verify the sender is a non 0::/0 value and is different from what is present in the
trusted mobile access gateway, authorized to send Proxy Binding currently active binding cache entry for that mobile node, the
Updates requests on behalf of that mobile nodes, using its own local mobility anchor MUST reject the request and send a Proxy
identity. The local mobility anchor must check the local/remote Binding Acknowledgement message with Status field set to 129
policy store to ensure the requesting node is authorized to send (Administratively Prohibited).
Proxy Binding Update messages.
The local mobility anchor MUST use the MN-Identifier from the NAI o Upon accepting a Proxy Binding Update request for extending the
option of the Proxy Binding Update message for identifying the mobile lifetime of a currently active binding for a mobile node, the
node. local mobility anchor MUST update the existing Binding Cache entry
for this mobile node. Unless there exists an established tunnel
to the mobile access gateway with the same transport and
encapsulation mode, the local mobility anchor MUST create a tunnel
to the mobile access gateway, as described in [RFC-2473] and also
delete the existing tunnel established with the previous mobile
access gateway. It MUST also send a Proxy Binding Acknowledgment
message to the mobile access gateway with the Status field set to
0 (Proxy Binding Update Accepted).
The local mobility anchor MUST ignore the sequence number field in Binding De-Registration:
the Proxy Binding Updates requests, if the Time-Stamp Option is
present in the message. It must also skip all the checks related to
sequence number that are required as per the Mobile IPv6
specification [RFC-3775]. However, the received sequence number MUST
be copied and returned in the Proxy Binding Acknowledgement message
sent to the mobile access gateway.
The local mobility anchor before accepting a Proxy Binding Update o If the received Proxy Binding Update request with the lifetime
request containing the Home Network Prefix Option with a specific value of 0, has a Source Address in the IPv6 header, different
prefix, MUST ensure the prefix is owned by the local mobility anchor from what is present in the Proxy-CoA address field in its Binding
and further the mobile node is authorized to use that prefix. If the Cache entry, the local mobility anchor MAY either choose to ignore
Home Network Prefix Option has the value 0::/0, the local mobility the request or send a valid Proxy Binding Acknowledgement message
anchor MUST allocate a prefix for the mobile node and send a Proxy with the Status field set to 0 (Proxy Binding Update Accepted).
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 o Upon accepting the Proxy Binding Update request for a mobile node,
gateway, the local mobility anchor must check if there exists a with the lifetime value of zero, the local mobility anchor MUST
binding cache entry for that mobile node, identified using the MN- wait for MinDelayBeforeBCEDelete [Section 9] amount of time,
Identifier, that was created due to a direct registration from the before it deletes the mobile node's Binding Cache entry. Within
mobile node. If there exists a binding cache entry with the proxy this wait period, if the local mobility anchor receives a Proxy
registration flag turned off, the local mobility anchor MUST NOT Binding Update request message for the same mobile node and from a
modify that binding state, instead it must create a tentative binding different mobile access gateway, with the lifetime value of
cache entry and update the tentative binding cache entry fields of greater than zero, and if that request is accepted, then the
that binding cache entry. Binding Cache entry MUST NOT be deleted, but must be updated with
the new values. However, the local mobile anchor MUST send the
Proxy Binding Acknowledgment message, immediately upon accepting
the request.
Upon receiving a Binding Update request from a mobile node with o Upon accepting the request, the local mobility anchor MUST delete
lifetime value set to 0, from a tunnel between itself and a trusted the mobile node's Binding Cache entry and remove the Routing state
mobile access gateway, the local mobility anchor upon accepting that for the mobile node's home network prefix.
de-registration message, MUST forward the Binding Acknowledgement
message in the tunnel from where it received the Binding Update
request. It must also replace the binding cache entry with the
tentative binding cache entry and enable routing for the mobile
node's home network prefix through the proxy mobile IPv6 tunnel.
Upon accepting this Proxy Binding Update message, the local mobility Constructing Proxy Binding Acknowledgement Message
anchor must create a Binding Cache entry and must set up a tunnel to
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.
The Proxy Binding Acknowledgment message must be constructed as shown o The local mobility anchor when sending the Proxy Binding
below. Acknowledgment message to the mobile access gateway MUST construct
the message as specified below.
IPv6 header (src=LMAA, dst=Proxy-CoA) IPv6 header (src=LMAA, dst=Proxy-CoA)
Mobility header Mobility header
-BA /*P flag is set*/ -BA /*P flag is set*/
Mobility Options Mobility Options
- Home Network Prefix Option - Home Network Prefix Option
- TimeStamp Option (optional) - Link-local Address Option (optional)
- Timestamp Option (optional)
- NAI Option - NAI Option
Proxy Binding Acknowledgment message contents Proxy Binding Acknowledgment message contents
o The Source Address field in the IPv6 header of the message SHOULD
be set to the destination address of the received Proxy Binding
Update request.
5.8.2. Extending the binding lifetime o The Destination Address field in the IPv6 header of the message
SHOULD be set to the source address of the received Proxy Binding
Update request.
Upon accepting the Proxy Binding Update request for extending the o If the Status field is set to a value greater less than 128, i.e.
lifetime of a currently active binding, the local mobility anchor if the binding request was rejected, then the prefix value in the
MUST update the lifetime for that binding and send a Proxy Binding Home Network Prefix option MUST be set to the prefix value from
Acknowledgment message to the mobile access gateway. The Proxy the received Home Network Prefix option. For all other cases, the
Binding Acknowledgment message MUST be constructed as specified in prefix value MUST be set to the allocated prefix value for that
Section 5.8.1. mobile node.
5.8.3. De-registration of the binding o The Link-local Address option MUST be present in the Proxy Binding
Acknowledgement message, if the same option was present in the
corresponding Proxy Binding Update request message. If there is
an existing Binding Cache entry for that mobile node with the
link-local address value of ALL_ZERO (value not set), or if there
was no existing Binding Cache entry, then the link-local address
MUST be copied from the received Link-local Address option in the
received Proxy Binding Update request. For all other cases, it
MUST be copied from the Binding Cache entry.
Upon accepting the Proxy Binding Update request sent with the o Considerations from Section 5.4 must be applied for constructing
lifetime value of zero, the local mobility anchor MUST delete the the Timestamp option.
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 o The identifier in the NAI option MUST be copied from the received
tunnel for that mobile node's home network prefix. Proxy Binding Update request. If the Status field value is set to
MISSING_MN_IDENTIFIER_OPTION, the NAI option MUST NOT be present
in the reply message.
5.9. Local Mobility Anchor Operational Summary o The message SHOULD 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.
o For supporting this scheme, the local mobility anchor MUST satisfy 5.4. Timestamp Option for Message Ordering
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 Mobile IPv6 [RFC-3775] uses the Sequence Number field in binding
this specification, the local mobility anchor service MUST NOT be registration messages as a way for the home agent to process the
tied to a specific interface. It SHOULD be able to accept Proxy binding updates in the order they were sent by a mobile node. The
Binding Update requests sent to any of the addresses configured on home agent and the mobile node are required to manage this counter
any of its interfaces. over the lifetime of a binding. However, in Proxy Mobile IPv6, as
the mobile node moves from one mobile access gateway to another and
in the absence of context transfer mechanism, the serving mobile
access gateway will be unable to determine the sequence number that
it needs to use in the signaling messages. Hence, the sequence
number scheme as specified in [RFC-3775], will be insufficient for
Proxy Mobile IPv6.
o The requirement for a home agent to maintain a list of home agents If the local mobility anchor cannot determine the sending order of
for a mobile node's home link is not applicable for the local the received binding registration messages, it may potentially
mobility anchor, when supporting Per-MN-Prefix addressing model. process an older message sent by a mobile access gateway, where the
mobile node was previously anchored, resulting in an incorrect
binding cache entry.
o The local mobility anchors SHOULD drop all HoTI messages received For solving this problem, this specification RECOMMENDS the use of
for a home address that has corresponding Binding Cache entry with Timestamp option [Section 8.4]. The basic principle behind the use
the proxy registration flag set. of timestamps in binding registration messages is that the node
generating the message inserts the current time-of-day, and the node
receiving the message checks that this timestamp is greater than all
previously accepted timestamps.
o The local mobility anchor must handle the mobile node's data Alternatively, the specification also allows the use of Sequence
traffic as explained in the Routing Considerations section of this Number based scheme, as per [RFC-3775]. The sequence number MUST be
maintained on a per mobile node basis and MUST be synchronized
between the serving mobile access gateways. However, the specific
details on how a mobile node's sequence number is synchronized
between different mobile access gateways is outside the scope of this
document. document.
6. Mobile Access Gateway Operation Using Timestamps based approach:
The Proxy Mobile IPv6 scheme specified in this document, introduces a o An implementation MUST support Timestamp option. If the Timestamp
new functional entity, the Mobile Access Gateway (MAG). It is the option is present in the received Proxy Binding Update request
entity that detects the mobile node's movements and initiates the message, then the local mobility anchor MUST include a valid
signaling with the mobile node's local mobility anchor for updating Timestamp option in the Proxy Binding Acknowledgment message that
the route to the mobile node's home address. In essence, the mobile it sends to the mobile access gateway.
access gateway performs mobility management on behalf of the mobile
node.
From the perspective of the local mobility anchor, the mobile access o All the mobility entities in a Proxy Mobile IPv6 domain,
gateway is a special element in the network that sends Mobile IPv6 exchanging binding registration messages using Timestamp option
signaling messages on behalf of a mobile node, but using its own must have adequately synchronized time-of-day clocks. These nodes
identity. It is the entity that binds the mobile node's home address SHOULD synchronize their clocks to a common time source, such as
to an address on its own access interface. using Network Time Protocol [RFC-1305] or in any other ways
suitable for that specific deployment.
The mobile access gateway has the following functional roles. o Upon receipt of a Proxy Binding Update message with the Timestamp
option, the local mobility anchor MUST check the timestamp field
for validity. In order for it to be considered valid, the
timestamp value contained in the Timestamp option MUST be close
enough to the local mobility anchor's time-of-day clock and the
timestamp MUST be greater than all previously accepted timestamps
in the Proxy Binding Update messages sent for that mobile node.
o Responsible for detecting the mobile node's attachment or o If the Timestamp option is present in the received Proxy Binding
detachment on the connected access link and for initiating the Update message, the local mobility anchor MUST ignore the sequence
mobility signaling with the mobile node's local mobility anchor. number field in the message. However, it MUST copy the sequence
number from the received Proxy Binding Update message to the Proxy
Binding Acknowledgement message.
o Emulation of the mobile node's home link on the access link. o If the timestamp value in the received Proxy Binding Update is
valid, the local mobility anchor MUST return the same timestamp
value in the Timestamp option included in the Proxy Binding
Acknowledgment message that it sends to the mobile access gateway.
o Registering the binding state at the mobile node's local mobility o If the timestamp value in the received Proxy Binding Update is not
anchor. valid, the local mobility anchor MUST reject the Proxy Binding
Update and send a Proxy Binding Acknowledgement message with
Status field set to TIMESTAMP_MISMATCH (Timestamp mismatch). The
message MUST also include the Timestamp option with the value set
to the current time-of-day on the local mobility anchor.
o Responsible for setting up the data path for enabling the mobile Using Sequence Number based approach:
node to use an address from its home network prefix and use it
from the access link. o If the Timestamp option is not present in the received Proxy
Binding Update request, the local mobility anchor MUST fallback to
the Sequence Number based scheme. It MUST process the sequence
number field as specified in [RFC-3775]. Also, it MUST NOT
include the Timestamp option in the Proxy Binding Acknowledgment
messages that it sends to the mobile access gateway.
5.5. Routing Considerations
5.5.1. Bi-Directional Tunnel Management
o A bi-directional tunnel is established between the local mobility
anchor and the mobile access gateway with IP-in-IP encapsulation,
as described in [RFC-2473]. The tunnel end points are the Proxy-
CoA and LMAA. When using IPv4 transport with a specific
encapsulation mode, the end points of the tunnel are the IPv4-LMAA
and IPv4-Proxy-CoA, as specified in [ID-IPV4-PMIP6].
o The bi-directional tunnel is used for routing the mobile node's
data traffic between the mobile access gateway and the local
mobility anchor. The tunnel hides the topology and enables a
mobile node to use an address from its home network prefix from
any access link attached to the mobile access gateway.
o The bi-directional tunnel is established after accepting the Proxy
Binding Update request message. The created tunnel may be shared
with other mobile nodes attached to the same mobile access gateway
and with the local mobility anchor having a binding cache entry
for those mobile nodes. Implementations MAY choose to use static
tunnels as supposed to dynamically creating and tearing them down
on a need basis.
o The tunnel between the local mobility anchor and the mobile access
gateway is typically a shared tunnel and can be used for routing
traffic streams for different mobile nodes attached to the same
mobile access gateway.
o Implementations typically use a software timer for managing the
tunnel lifetime and a counter for keeping a count of all the
mobile nodes that are sharing the tunnel. The timer value will be
set to the accepted binding life-time and will be updated after
each periodic registrations for extending the lifetime. If the
tunnel is shared for multiple mobile nodes, the tunnel lifetime
will be set to the highest binding lifetime that is granted to any
one of those mobile nodes sharing that tunnel.
5.5.2. Forwarding Considerations
Intercepting Packets Sent to the Mobile Node's Home Network
o When the local mobility anchor is serving a mobile node, it MUST
be able to receive packets that are sent to the mobile node's home
network. In order for it to receive those packets, it MUST
advertise a connected route in to the Routing Infrastructure for
the mobile node's home network prefix or for an aggregated prefix
with a larger scope. This essentially enables IPv6 routers in
that network to detect the local mobility anchor as the last-hop
router for that prefix.
Forwarding Packets Sent by the Mobile Node to the Corresponding Node
o On receiving a packet from a corresponding node with the
destination address matching a mobile node's home network prefix,
the local mobility anchor MUST forward the packet through the bi-
directional tunnel setup for that mobile node. The format of the
tunneled packet is shown below.
IPv6 header (src= LMAA, dst= Proxy-CoA /* Tunnel Header */
IPv6 header (src= CN, dst= MN-HNP ) /* Packet Header */
Upper layer protocols /* Packet Content*/
Figure 6: Tunneled Packets from LMA to MAG
Forwarding Packets Sent by the Corresponding Node to the Mobile Node
o All the reverse tunneled packets that the local mobility anchor
receives from the mobile access gateway, after removing the tunnel
header MUST be routed to the destination specified in the inner
packet header. These routed packets will have the source address
field set to the mobile node's home address.
5.6. Local Mobility Anchor Address Discovery
Dynamic Home Agent Address Discovery, as explained in Section 10.5
[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
message to the Mobile IPv6 Home-Agents anycast address, derived from
its home network prefix.
The DHAAD message in the current form cannot be used in Proxy Mobile
IPv6 for discovering the address of the mobile node's local mobility
anchor. In Proxy Mobile IPv6, the local mobility anchor will not be
able to receive any messages sent to the Mobile IPv6 Home-Agents
anycast address corresponding to the mobile node's home network
prefix, as the prefix is not hosted on any of its interfaces.
Further, the mobile access gateway will not predictably be able to
locate the serving local mobility anchor that has the mobile node's
binding cache entry. Hence, this specification does not support
Dynamic Home Agent Address Discovery protocol.
In Proxy Mobile IPv6, the address of the local mobility anchor
configured to serve a mobile node can be discovered by the mobility
entities in other ways. This may be a configured entry in the mobile
node's policy profile, or it may be obtained through mechanisms
outside the scope of this document.
5.7. Mobile Prefix Discovery Considerations
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
Mobile Prefix Advertisement to the mobile node.
In Proxy Mobile IPv6, the mobile node's home network prefix is hosted
on the access link connected to the mobile access gateway. but it is
topologically anchored on the local mobility anchor. Since, there is
no physical home-link for the mobile node's home network prefix on
the local mobility anchor and as the mobile node is always on the
link where the prefix is hosted, any prefix change messages can just
be advertised by the mobile access gateway on the access link and
thus there is no applicability of this message for Proxy Mobile IPv6.
Hence, this specification does not support Mobile Prefix Discovery.
5.8. Route Optimizations Considerations
The Route Optimization in Mobile IPv6, as defined in [RFC-3775],
enables a mobile node to communicate with a corresponding node
directly using its care-of address and further the Return Routability
procedure enables the corresponding node to have reasonable trust
that the mobile node is reachable at both its home address and
care-of address.
In Proxy Mobile IPv6, the mobile node is not involved in any mobility
related signaling. The mobile node uses only its home address for
all its communication and the Care-of address (Proxy-CoA) is not
visible to the mobile node. Hence, the Return Routability procedure
as defined in Mobile IPv6 cannot be used in Proxy Mobile IPv6.
6. Mobile Access Gateway Operation
The Proxy Mobile IPv6 protocol described in this document, introduces
a new functional entity, the Mobile Access Gateway (MAG). The mobile
access gateway is the entity that is responsible for detecting the
mobile node's movements on its access link and sending the binding
registration requests to the local mobility anchor. In essence, the
mobile access gateway performs mobility management on behalf of a
mobile node.
The mobile access gateway is a function that typically runs on an The mobile access gateway is a function that typically runs on an
access router. However, implementations MAY choose to split this access router. However, implementations MAY choose to split this
function and run it across multiple systems. The specifics on how function and run it across multiple systems. The specifics on how
that is achieved is beyond the scope of this document. that is achieved is beyond the scope of this document.
6.1. Supported Access Link Types The mobile access gateway has the following key functional roles:
This specification supports only point-to-point access link types and o It is responsible for detecting the mobile node's movements on the
thus it assumes that the link between the mobile node and the mobile access link and for initiating the mobility signaling with the
access gateway is a dedicated link and that the mobile node and the mobile node's local mobility anchor.
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.
Support for shared links or other link types is left for the future o Emulation of the mobile node's home link on the access link by
work. sending Router Advertisements with the mobile node's home network
prefix information.
6.2. Supported Home Network Prefix Models o Responsible for setting up the data path for enabling the mobile
node to configure an address from its home network prefix and use
it from its access link.
This specification supports Per-MN-Prefix model and does not support 6.1. Extensions to Binding Update List Entry Data Structure
Shared-Prefix model. As per the Per-MN-Prefix model, there will be a
unique home network prefix assigned for each mobile node and no other
host shares an address from that prefix. The prefix is always hosted
on the access link where the mobile node is anchored. Conceptually,
the prefix follows the mobile node as it moves within the proxy
mobile IPv6 domain. However, from the routing perspective, the home
network prefix is topologically anchored on the local mobility
anchor.
6.3. Supported Address Configuration Models Every mobile access gateway MUST maintain a Binding Update List.
Each entry in the Binding Update List represents a mobile node's
mobility binding with its local mobility anchor. The Binding Update
List is a conceptual data structure, described in Section 11.1 [RFC-
3775].
A mobile node in the proxy mobile IPv6 domain can configure one or For supporting this specification, the conceptual Binding Update List
more IPv6 addresses on its interface using Stateless or Stateful entry data structure needs be extended with the following additional
address autoconfiguration procedures. The Router Advertisement fields.
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, o The Identifier of the attached mobile node, MN-Identifier. This
the mobile node can generate one or more IPv6 addresses by combining identifier is acquired during the mobile node's attachment to the
the network prefix advertised on the access link with an interface access link or through mechanisms outside the scope of this
identifier, using the techniques described in Stateless document.
Autoconfiguration specification [RFC-2462] or in Privacy extension
specification [RFC-3041].
When stateful address autoconfiguration is supported on the link, the o The Link-layer address of the mobile node. This address can be
mobile node obtains the address configuration from the DHCPv6 server acquired from the received Router Solicitation messages from the
using DHCPv6 client protocol, as specified in DHCPv6 specification mobile node or during the mobile node's attachment to the access
[RFC-3315]. network.
In addition to this, other address configuration mechanisms specific o The IPv6 home network prefix of the attached mobile node. The
to the access link between the mobile node and the mobile access home network prefix of the mobile node is acquired from the mobile
gateway may also be used for pushing the address configuration to the node's local mobility anchor through the received Proxy Binding
mobile node. Acknowledgment messages. The IPv6 home network prefix also
includes the corresponding prefix length.
6.4. Access Authentication & Mobile Node Identification o The Link-local address of the mobile node on the interface
attached to the access link.
When a mobile node attaches to an access link connected to the mobile o The IPv6 address of the local mobility anchor serving the attached
access gateway, the deployed access security protocols on that link mobile node. This address is acquired from the mobile node's
will ensure that the network-based mobility management service is policy profile.
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.
6.5. Mobile Node's Policy Profile o The interface identifier of the access link where the mobile node
is currently attached. The interface identifier is acquired
during the mobile node's attachment to the access link.
o The interface identifier of the bi-directional tunnel between the
mobile node's local mobility anchor and the mobile access gateway.
The tunnel interface identifier is acquired during the tunnel
creation.
6.2. Mobile Node's Policy Profile
A mobile node's policy profile contains the essential operational A mobile node's policy profile contains the essential operational
parameters that are required by the network entities for managing the parameters that are required by the network entities for managing the
mobile node's mobility service. These policy profiles are stored in mobile node's mobility service. These policy profiles are stored in
a local or a remote policy store, the mobile access gateway and the 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 local mobility anchor MUST be able to obtain a mobile node's policy
profile using its MN-Identifier. The policy profile may also be profile. The policy profile may also be handed over to a serving
handed over to a serving mobile access gateway as part of a context mobile access gateway as part of a context transfer procedure during
transfer procedure during a handoff. The exact details on how this a handoff. The exact details on how this achieved is outside the
achieved is outside the scope of this document. However, this scope of this document. However, this specification requires that a
specification requires that a mobile access gateway serving a mobile mobile access gateway serving a mobile node MUST have access to its
node MUST have access to its policy profile. policy profile.
The following are the mandatory fields of the policy profile: The following are the mandatory fields of the policy profile:
o The mobile node's identifier (MN-Identifier) o The mobile node's identifier (MN-Identifier)
o The IPv6 address of the local mobility anchor (LMAA) o The IPv6 address of the local mobility anchor (LMAA)
o Supported address configuration procedures on the link (Stateful, o Supported address configuration procedures on the link (Stateful,
Stateless or both) Stateless or both)
The following are the optional fields of the policy profile: 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 (MN-HNP)
o The mobile node's IPv6 home network prefix length
6.6. Conceptual Data Structures 6.3. Supported Access Link Types
Every mobile access gateway MUST maintain a Binding Update List for This specification supports only point-to-point access link types and
each currently attached mobile node. The Binding Update List is a thus it assumes that the mobile node and the mobile access gateway
conceptual data structure, described in Section 11.1 of Mobile IPv6 are the only two nodes on the access link. The link is assumed to
base specification [RFC-3775]. For supporting this specification, have multicast capability.
the conceptual Binding Update List data structure must be extended
with the following new additional fields.
o The Identifier of the mobile node, MN-Identifier. 6.4. Supported Address Configuration Models
o The MAC address of the mobile node's connected interface. A mobile node in the Proxy Mobile IPv6 domain can configure one or
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. 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.
o The IPv6 home network prefix of the mobile node. 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 as per Privacy
extension specification [RFC-3041].
o The IPv6 home network prefix length of the mobile node. When stateful address autoconfiguration is supported on the link, the
mobile node can obtain the address configuration from the DHCPv6
server using DHCPv6 client protocol, as specified in DHCPv6
specification [RFC-3315].
o The interface identifier of the point-to-point link to the mobile Additionally, 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. node.
o The interface identifier of the tunnel between the mobile access 6.5. Access Authentication & Mobile Node Identification
gateway and the mobile node's local mobility anchor.
6.7. Home Network Emulation When a mobile node attaches to an access link connected to the mobile
access gateway, the deployed access security protocols on that link
SHOULD 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 between the mobile node and mobile access gateway,
before the protocol operation begins.
One of the key functions of a mobile access gateway is to emulate the 6.6. Acquiring Mobile Node's Identifier
mobile node's home network prefix on the access link. It must
ensure, the mobile node believes it is still connected to its home
link or on the link where it obtained its address configuration after
it moved into that proxy mobile IPv6 domain.
After detecting new mobile node on its access link and after a All the network entities in a Proxy Mobile IPv6 domain MUST be able
successful access authentication and authorization of the mobile node to identify a mobile node, using its MN-Identifier. This identifier
for network-based mobility service, the mobile access gateway MUST to MUST be stable across the Proxy Mobile IPv6 domain and the entities
emulate the mobile node's home link by sending the Router must be able to use this identifier in the signaling messages.
Advertisements with the mobile node's home network prefix as the Typically, this identifier is obtained as part of the access
hosted on-link prefix. The Router Advertisement MUST be sent in authentication or through other means as specified below.
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.
For emulating the mobile node's home link on the access link, the o The identifier of the mobile node that the mobile access gateway
mobile access gateway must know the home network prefix of the mobile obtains as part of the access authentication or from the notified
node for constructing the Router Advertisement. Typically and as a network attachment event, can be a temporary identifier and this
default method, the mobile access gateway learns the mobile node's identifier may also change at each re-authentication. However,
home network prefix information from the Proxy Binding the mobile access gateway MUST be able to authenticate the mobile
Acknowledgement message, it received in response to the Proxy Binding node based on this identifier and MUST be able to obtain the MN-
Update message that it sent to the mobile node's local mobility Identifier from the policy store, such as from the RADIUS
anchor for that mobile node. attribute, Chargeable-User-Identifier.
However, it is also possible, the mobile node's home network prefix o The MN-Identifier that the policy store delivers to the mobile
information may be statically configured in the mobile node's policy access gateway MAY NOT be the true identifier of the mobile node.
profile or it may be handed over to the mobile access gateway as part However, the mobility access gateway MUST be able to use this
of a context transfer procedure. If the mobile access gateway can identifier in the signaling messages exchanged with the local
predictably know the mobile node's home network prefix information, mobility anchor.
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 o The mobile access gateway MUST be able identify the mobile node by
mobile node is a point-to-point link, the Router Advertisements its MN-Identifier and it MUST be able to associate this identity
advertising a specific home network prefix is received only by the to the sender of any IPv4 or IPv6 packets on the access link.
respective mobile node and hence there is clearly a unique link for
each mobile node that is attached to that mobile access gateway.
6.7.1. Home Network Prefix Renumbering 6.7. Home Network Emulation
If the mobile node's home network prefix gets renumbered or becomes One of the key functions of a mobile access gateway is to emulate the
invalid during the middle of a mobility session, the mobile access mobile node's home network on the access link. It must ensure, the
gateway MUST withdraw the prefix by sending a Router Advertisement on mobile node believes it is still connected to its home link or on the
the access link with zero prefix lifetime for the mobile node's home link where it obtained its initial address configuration after it
network prefix. Also, the local mobility anchor and the mobile moved into that Proxy Mobile IPv6 domain.
access gateway MUST delete the routing state for that prefix.
However, the specific details on how the local mobility anchor For emulating the mobile node's home link on the access link, the
notifies the mobile access gateway is outside the scope of this mobile access gateway must be able to send Router Advertisements
document. advertising the mobile node's home network prefix and other address
configuration parameters consistent with its home link properties.
Typically, the mobile access gateway learns the mobile node's home
network prefix information from the received Proxy Binding
Acknowledgement message or it may be obtained from the mobile node's
policy profile. However, the mobile access gateway SHOULD send the
Router Advertisements advertising the mobile node's home network
prefix only after successfully completing the binding registration
with the mobile node's local mobility anchor.
6.8. Link-Local and Global Address Uniqueness 6.8. Link-Local and Global Address Uniqueness
A mobile node in the proxy mobile IPv6 domain, as it moves from one A mobile node in the Proxy Mobile IPv6 domain, as it moves from one
mobile access gateway to the other, it will continue to detect its 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 home network and thus making it believe it is still on the same link.
link. Every time the mobile node attaches to a new link, the event Every time the mobile node attaches to a new link, the event related
related to the interface state change, will trigger the mobile node to the interface state change, will trigger the mobile node to
to perform DAD operation on the link-local and global addresses. perform DAD operation on the link-local and global addresses.
However, if the node is DNAv6 enabled, as specified in [ID-DNAV6], it However, if the mobile node is DNAv6 enabled, as specified in [ID-
may not detect the link change due to DNAv6 optimizations and hence DNAV6], it may not detect the link change due to DNAv6 optimizations
it will not trigger the duplicate address detection (DAD) procedure and may not trigger the duplicate address detection (DAD) procedure
for establishing the link-local address uniqueness on that new link. for establishing the link-local address uniqueness on that new link.
Further, if the mobile node uses an interface identifier that is not Further, if the mobile node uses an interface identifier that is not
based on EUI-64 identifier, such as specified in IPv6 Stateless based on EUI-64 identifier, such as specified in IPv6 Stateless
Autoconfiguration specification [RFC-2462], there is a possibility, Autoconfiguration specification [RFC-2462], there is a possibility,
with the odds of 1 to billion, of a link-local address collision with the odds of 1 to billion, of a link-local address collision
between the two neighbors, the mobile node and the mobile access between the two neighbors on that access link.
gateway.
One of the workarounds for this issue is to set the DNAv6 One of the workarounds for this issue is to set the DNAv6
configuration parameter, DNASameLinkDADFlag to TRUE and that will configuration parameter, DNASameLinkDADFlag to TRUE and that will
force the mobile node to redo DAD operation every time the interface force the mobile node to redo DAD operation every time the interface
comes up, even when DNAv6 does detect a link change . comes up, even when DNAv6 does detect a link change .
However, this issues will not impact point-to-point links based on 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 PPP session. Each time the mobile node moves and attaches to a new
mobile access gateway, either the PPP session [RFC-1661] is mobile access gateway, either the PPP session [RFC-1661] is
reestablished or the PPP session may be moved as part of context reestablished or the PPP session may be moved as part of context
skipping to change at page 27, line 7 skipping to change at page 29, line 37
node is DNAv6 capable, the mobile node always configures a new link- node is DNAv6 capable, the mobile node always configures a new link-
local address when ever it moves to a new link. local address when ever it moves to a new link.
If the PPP session state is moved to the new mobile access gateway, If the PPP session state is moved to the new mobile access gateway,
as part of context transfer procedures that are in place, there will as part of context transfer procedures that are in place, there will
not be any change to the interface identifiers of the two nodes on not be any change to the interface identifiers of the two nodes on
that point-to-point change. The whole link is moved to the new that point-to-point change. The whole link is moved to the new
mobile access gateway and there will not be any need for establishing mobile access gateway and there will not be any need for establishing
link-local address uniqueness on that link. link-local address uniqueness on that link.
Alternatively, this specification allows the mobile access gateway to
upload the mobile node's link-local address to the local mobility
anchor using the Link-local Address option, exchanged in the binding
registration messages. The mobile access gateway can learn the
mobile node's link-local address, by snooping the DAD messages sent
by the mobile node for establishing the link-local address uniqueness
on the access link. Subsequently, at each handoff, the mobile access
gateway can obtain this address from the local mobility anchor and
can change its own link-local address, if it detects an address
collision.
This issue is not relevant to the mobile node's global address. This issue is not relevant to the mobile node's global address.
Since, there is a unique home network prefix for each mobile node, Since, there is a unique home network prefix for each mobile node,
the uniqueness for the mobile node's global address is ensured on the the uniqueness for the mobile node's global address is assured on the
access link. access link.
6.9. Signaling Considerations 6.9. Signaling Considerations
6.9.1. Initial Attachment and binding registration Initial Attachment and binding registration
After detecting a new mobile node on its access link after a o After detecting a new mobile node on its access link, the mobile
successful access authentication and authorization, the mobile access access gateway MUST send a Proxy Binding Update message to the
gateway MUST send a Proxy Binding Update message to the mobile node's mobile node's local mobility anchor.
local mobility anchor.
The Proxy Binding Update message must be constructed as shown below. o The Proxy Binding Update message that the mobile access gateway
sends to the mobile node's local mobility anchor MUST have the NAI
option, identifying the mobile node, the Home Network Prefix
option and optionally the Timestamp option or a valid sequence
number.
o If the mobile access gateway learns the mobile node's home network
prefix either from its policy store or from other means, the
mobile access gateway MAY choose to specify the same in the Home
Network Prefix option for requesting the local mobility anchor to
allocate that prefix. If the specified value is 0::/0, then the
local mobility anchor will consider this as a request for prefix
allocation.
o If the mobile access gateway receives a Proxy Binding
Acknowledgment with the Status field value set to 0 (Proxy Binding
Update accepted), the mobile access gateway MUST create Binding
Update List entry for the mobile node and must setup a tunnel to
the mobile node's local mobility anchor, as explained in section
6.10. The mobile access gateway MUST also add a policy route for
tunneling all the packets that it receives from the mobile node to
its local mobility anchor.
o If the mobile access gateway receives a Proxy Binding
Acknowledgment with the Status field value greater than 128
(binding request is rejected), the mobile access gateways MUST NOT
advertise the mobile node's home network prefix on the access link
and there by denying mobility service to the mobile node.
Extending the binding lifetime
o For extending the lifetime of a currently existing binding at the
local mobility, the mobile access gateway MUST send a Proxy
Binding Update message, before the expiry of the currently
accepted binding.
De-Registration of the binding
o 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.
o 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.
Constructing Proxy Binding Update Message
o The mobile access gateway when sending the Proxy Binding Update
request to the local mobility anchor MUST construct the message as
specified below.
IPv6 header (src=Proxy-CoA, dst=LMAA) IPv6 header (src=Proxy-CoA, dst=LMAA)
Mobility header Mobility header
-BU /*P flag is set*/ -BU /*P & A flags are set*/
Mobility Options Mobility Options
- Home Network Prefix Option* - Home Network Prefix option
- TimeStamp Option (optional) - Link-local Address option (Optional)
- Timestamp Option (optional)
- NAI Option - NAI Option
*Home Network Prefix option may contain 0::/0 or a specific prefix.
Proxy Binding Update message contents Proxy Binding Update message contents
The Proxy Binding Update message that the mobile access gateway sends o The Source Address field in the IPv6 header of the message SHOULD
to the mobile node's local mobility anchor MUST have the NAI option, be set to the address of the mobile access gateway.
identifying the mobile node, the Home Network Prefix option and
optionally the Time Stamp option SHOULD be present. The Time Stamp
option is not required if the mobile access gateway can send a valid
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.
If the mobile access gateway learns the mobile node's home network
prefix either from its policy store or from other means, the mobile
access gateway MAY choose to specify the same in the Home Network
Prefix option for requesting the local mobility anchor to register
that prefix. If the specified value is 0::/0, then the local
mobility anchor will allocate a prefix to the mobile node.
After receiving a Proxy Binding Acknowledgment with the status code
indicating the acceptance of the Proxy Binding Update, the mobile
access gateway MUST setup a tunnel to the mobile node's local
mobility anchor, as explained in section 6.10. The mobile access
gateway MUST also add a policy route for tunneling all the packets
that it receives from the mobile node to its local mobility anchor.
If the local mobility anchor rejects the Proxy Binding Update o The Destination Address field in the IPv6 header of the message
message, the mobile access gateways MUST NOT advertise the mobile SHOULD be set to the local mobility anchor address.
node's home prefix on the access link and there by denying mobility
service to the mobile node.
6.9.2. Extending the binding lifetime o The Home Network Prefix option MUST be present. The prefix value
may be set 0::/0 or to a specific value.
For extending the lifetime of a currently existing binding at the o The Link-local Address option MAY be present. The value may be
local mobility, the mobile access gateway MUST send a Proxy Binding set to ALL_ZERO or the mobile node's link-local address.
Update message with a specific lifetime. The message MUST be
constructed as specified in Section 6.9.1.
6.9.3. De-registration of the binding o Considerations from Section 5.4 must be applied for constructing
the Timestamp option.
At any point, the mobile access gateway detects that the mobile node o The NAI option MUST be present, the identifier field in the option
has moved away from its access link, it MUST send a Proxy Binding MUST be set to mobile node's identifier, MN-Identifier.
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 o The message SHOULD be protected by using IPsec ESP, using the
tunnel for that mobile node and delete the Binding Update List for security association existing between the local mobility anchor
that mobile node, either upon receiving an Proxy Binding and the mobile access gateway, created either dynamically or
Acknowledgment message from the local mobility anchor or after a statically.
certain timeout waiting for the acknowledgment message.
6.10. Routing Considerations 6.10. Routing Considerations
This section describes how the mobile access gateway handles the This section describes how the mobile access gateway handles the
traffic to/from the mobile node that is attached to one of its access traffic to/from the mobile node that is attached to one of its access
interface. interface.
Proxy-CoA LMAA Proxy-CoA LMAA
| | | |
+--+ +---+ +---+ +--+ +--+ +---+ +---+ +--+
|MN|----------|MAG|======================|LMA|----------|CN| |MN|----------|MAG|======================|LMA|----------|CN|
+--+ +---+ +---+ +--+ +--+ +---+ +---+ +--+
IPv6 Tunnel IPv6 Tunnel
6.10.1. Transport Network 6.10.1. Transport Network
The transport network between the local mobility anchor and the The transport network between the local mobility anchor and the
mobile access can be either an IPv6 or IPv4 network. However, this mobile access can be either an IPv6 or IPv4 network. However, this
specification only deals with the scenario where the transport specification only deals with the IPv6 transport and the companion
network between the mobility entities is IPv6-only and requires document [ID-IPV4-PMIP6] specifies the required extensions for
reachability between the local mobility anchor and the mobile access negotiating IPv4 transport and the corresponding encapsulation mode,
gateway over IPv6 transport. Just as in Mobile IPv6 specification for supporting this protocol operation.
[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 6.10.2. Tunneling & Encapsulation Modes
The IPv6 address that a mobile node uses from its home network prefix The IPv6 address that a mobile node uses from its home network prefix
is topologically anchored at the local mobility anchor. For a mobile is topologically anchored at the local mobility anchor. For a mobile
node to use this address from an access network attached to 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. access gateway, proper tunneling techniques have to be in place.
Tunneling hides the network topology and allows the mobile node's Tunneling hides the network topology and allows the mobile node's
IPv6 datagrams to be encapsulated as a payload of another IPv6 packet IPv6 datagrams to be encapsulated as a payload of another IPv6 packet
and be routed between the local mobility anchor and the mobile access and be routed between the local mobility anchor and the mobile access
skipping to change at page 30, line 12 skipping to change at page 33, line 22
be used by the mobile access gateway and the local mobility anchor be used by the mobile access gateway and the local mobility anchor
for routing mobile node's IPv6 datagrams. for routing mobile node's IPv6 datagrams.
o IPv6-In-IPv6 - IPv6 datagram encapsulated in an IPv6 packet. This o IPv6-In-IPv6 - IPv6 datagram encapsulated in an IPv6 packet. This
mechanism is defined in the Generic Packet Tunneling for IPv6 mechanism is defined in the Generic Packet Tunneling for IPv6
specification [RFC-2473]. specification [RFC-2473].
o IPv6-In-IPv4 - IPv6 datagram encapsulation in an IPv4 packet. The o IPv6-In-IPv4 - IPv6 datagram encapsulation in an IPv4 packet. The
details related to this encapsulation mode and the specifics on details related to this encapsulation mode and the specifics on
how this mode is negotiated is specified in the companion how this mode is negotiated is specified in the companion
document, IPv4 support for Proxy Mobile IPv6 [ID-IPv4-PMIP6]. document, IPv4 support for Proxy Mobile IPv6 [ID-IPV4-PMIP6].
o IPv6-In-IPv4-UDP - IPv6 datagram encapsulation in an IPv4 UDP o IPv6-In-IPv4-UDP - IPv6 datagram encapsulation in an IPv4 UDP
packet. The details related to this mode are covered in the packet. The details related to this mode are covered in the
companion document, IPv4 support for Proxy Mobile IPv6 [IPv4- companion document, IPv4 support for Proxy Mobile IPv6 [ID-IPV4-
PMIP6-SPEC]. PMIP6].
6.10.3. Routing State 6.10.3. Routing State
The following section explain the routing state for a mobile node on The following section explain the routing state for a mobile node on
the mobile access gateway. This routing state reflects only one the mobile access gateway. This routing state reflects only one
specific way of implementation and one MAY choose to implement it in specific way of implementation and one MAY choose to implement it in
other ways. The policy based route defined below acts as a traffic other ways. The policy based route defined below acts as a traffic
selection rule for routing a mobile node's traffic through a specific selection rule for routing a mobile node's traffic through a specific
tunnel created between the mobile access gateway and that mobile tunnel created between the mobile access gateway and that mobile
node's local mobility anchor and with the specific encapsulation node's local mobility anchor and with the specific encapsulation
skipping to change at page 30, line 45 skipping to change at page 34, line 12
MAC address, ingress interface or source prefix (MN-HNP) to MAC address, ingress interface or source prefix (MN-HNP) to
_ANY_DESTINATION_ route via interface tunnel0, next-hop LMAA. _ANY_DESTINATION_ route via interface tunnel0, next-hop LMAA.
+==================================================================+ +==================================================================+
| Packet Source | Destination Address | Destination Interface | | Packet Source | Destination Address | Destination Interface |
+==================================================================+ +==================================================================+
| MAC_Address_MN1, | _ANY_DESTINATION_ | Tunnel0 | | MAC_Address_MN1, | _ANY_DESTINATION_ | Tunnel0 |
| (IPv6 Prefix or |----------------------------------------------| | (IPv6 Prefix or |----------------------------------------------|
| Input Interface) | Locally Connected | Tunnel0 | | Input Interface) | Locally Connected | Tunnel0 |
+------------------------------------------------------------------+ +------------------------------------------------------------------+
| MAC_Address_MN2 | _ANY_DESTINATION_ | Tunnel1 | | MAC_Address_MN2, | _ANY_DESTINATION_ | Tunnel1 |
+ -----------------------------------------------| + (IPv6 Prefix or -----------------------------------------------|
| | Locally Connected | direct | | Input Interface | Locally Connected | direct |
+------------------------------------------------------------------+ +------------------------------------------------------------------+
Example - Policy based Route Table Example - Policy based Route Table
+==================================================================+ +==================================================================+
| Interface | Source Address | Destination Address | Encapsulation | | Interface | Source Address | Destination Address | Encapsulation |
+==================================================================+ +==================================================================+
| Tunnel0 | Proxy-CoA | LMAA1 | IPv6-in-IPv6 | | Tunnel0 | Proxy-CoA | LMAA1 | IPv6-in-IPv6 |
+------------------------------------------------------------------+ +------------------------------------------------------------------+
| Tunnel1 |IPv4-Proxy-CoA | IPv4-LMA2 | IPv6-in-IPv4 | | Tunnel1 |IPv4-Proxy-CoA | IPv4-LMA2 | IPv6-in-IPv4 |
+------------------------------------------------------------------+ +------------------------------------------------------------------+
Example - Tunnel Interface Table Example - Tunnel Interface Table
skipping to change at page 31, line 33 skipping to change at page 35, line 7
in the path for that traffic and it will not be able to apply any in the path for that traffic and it will not be able to apply any
traffic policies or do any accounting for those flows. traffic policies or do any accounting for those flows.
This decision of path optimization SHOULD be based on the configured This decision of path optimization SHOULD be based on the configured
policy configured on the mobile access gateway, but enforced by the policy configured on the mobile access gateway, but enforced by the
mobile node's local mobility anchor. The specific details on how mobile node's local mobility anchor. The specific details on how
this is achieved is beyond of the scope of this document. this is achieved is beyond of the scope of this document.
6.10.5. Tunnel Management 6.10.5. Tunnel Management
All the considerations mentioned in Section 5.2, for the tunnel All the considerations mentioned in Section 5.5.1, for the tunnel
management on the local mobility anchor apply for the mobile access management on the local mobility anchor apply for the mobile access
gateway as well. 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 6.10.6. Forwarding Rules
Upon receipt of an encapsulated packet sent to its configured Proxy- Upon receipt of an encapsulated packet sent to its configured Proxy-
CoA address i.e. on receiving a packet from a tunnel, the mobile CoA address i.e. on receiving a packet from a tunnel, the mobile
access gateway MUST use the destination address of the inner packet access gateway MUST use the destination address of the inner packet
for forwarding it to the interface where the prefix for that address for forwarding it to the interface where the prefix for that address
is hosted. The mobile access gateway MUST remove the outer header is hosted. The mobile access gateway MUST remove the outer header
before forwarding the packet. If the mobile access gateway cannot before forwarding the packet. If the mobile access gateway cannot
find the connected interface for that destination address, it MUST find the connected interface for that destination address, it MUST
silently drop the packet. For reporting an error in such scenario, silently drop the packet. For reporting an error in such scenario,
skipping to change at page 32, line 36 skipping to change at page 35, line 50
On receiving a packet from the mobile node to any destination i.e. On receiving a packet from the mobile node to any destination i.e.
not directly connected to the mobile access gateway, the packet MUST not directly connected to the mobile access gateway, the packet MUST
be forwarded to the local mobility anchor through the bi-directional be forwarded to the local mobility anchor through the bi-directional
tunnel established between itself and the mobile's local mobility tunnel established between itself and the mobile's local mobility
anchor. However, the packets that are sent with the link-local anchor. However, the packets that are sent with the link-local
source address MUST not be forwarded. source address MUST not be forwarded.
6.11. Interaction with DHCP Relay Agent 6.11. Interaction with DHCP Relay Agent
If Stateful Address Configuration using DHCP is supported on the link If Stateful Address Configuration using DHCP is supported on the link
on which the mobile node is attached, the DHCP relay agent [RFC-3315] where the mobile node is attached, the DHCP relay agent [RFC-3315]
needs to be configured on the access router. When the mobile node needs to be configured on that access link.
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
hint to the DHCP Server. Since, the access link is a point-to-point
link with the configured mobile node's prefix as the on-link prefix,
the normal DHCP relay agent configuration on the MAG will ensure the
prefix hint is set to the mobile node's home network prefix.
6.12. Mobile Node Detachment Detection and Resource Cleanup When the mobile node sends a DHCPv6 Request message, the DHCP relay
agent function on the access link will set the link-address field in
the DHCPv6 message to the mobile node's home network prefix, so as to
provide a prefix hint to the DHCP Server for the address pool
selection.
6.12. Home Network Prefix Renumbering
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 about the mobile node's home
network prefix renumbering is outside the scope of this document.
6.13. 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 SHOULD 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 the value set to 0. It MUST also remove any local state such as the
Binding Update List 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
skipping to change at page 33, line 26 skipping to change at page 37, line 4
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:
o Link-layer event specific to the access technology o Link-layer event specific to the access technology
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
6.13. Allowing network access to other IPv6 nodes 6.14. Allowing network access to other IPv6 nodes
In some proxy mobile IPv6 deployments, network operators may want to In some proxy mobile IPv6 deployments, network operators may want to
provision the mobile access gateway to offer network-based mobility provision the mobile access gateway to offer network-based mobility
management service only to some visiting mobile nodes and enable just management service only to some visiting mobile nodes and enable just
regular IPv6/IPv4 access to some other nodes attached to that mobile regular IPv6/IPv4 access to some other nodes attached to that mobile
access gateway. This requires the network to have the control on access gateway. This requires the network to have the control on
when to enable network-based mobility management service to a mobile when to enable network-based mobility management service to a mobile
node and when to enabled a regular IPv6 access. This specification node and when to enable regular IPv6 access. This specification does
does not disallow such configuration. 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 mobile access gateway must ensure the mobile such service, then the mobile access gateway must ensure the mobile
node believes it is on its home link, as explained in various node believes it is on its home link, as explained in various
sections of this specification. sections of this specification.
If the mobile node is not entitled for the network-based mobility If the mobile node is not entitled for the network-based mobility
management service, as enforced by the policy, the mobile access management service, as enforced by the policy, the mobile access
gateway MAY choose to offer regular IPv6 access to the mobile node gateway MAY choose to offer regular IPv6 access to the mobile node
and hence the normal IPv6 considerations apply. If IPv6 access is and hence the normal IPv6 considerations apply. If IPv6 access is
enabled, the mobile node SHOULD be able to obtain any IPv6 address enabled, the mobile node SHOULD be able to obtain any IPv6 address
using normal IPv6 address configuration mechanisms. The obtained using normal IPv6 address configuration mechanisms. The obtained
address must be from a local visitor network prefix. This address must be from a local visitor network prefix. This
essentially ensures, the mobile access gateway functions as any other essentially ensures, the mobile access gateway functions as any other
access router and does not impact the protocol operation of a mobile access router and does not impact the protocol operation of a mobile
node attempting to use host-based mobility management service when it node attempting to use host-based mobility management service when it
attaches to an access link connected to a mobile access gateway in a attaches to an access link connected to a mobile access gateway in a
proxy mobile IPv6 domain. Proxy Mobile IPv6 domain.
7. Mobile Node Operation 7. Mobile Node Operation
This non-normative section discusses the mobile node's operation in a This non-normative section explains the mobile node's operation in a
Proxy Mobile IPv6 domain. Proxy Mobile IPv6 domain.
Once the mobile node enters a Proxy Mobile IPv6 domain and attaches 7.1. Moving into a Proxy Mobile IPv6 Domain
to an access network and after the access authentication, the network
ensures, the mobile using any of the address configuration mechanisms
permitted by the network for that mobile node, will be able to obtain
an address and move anywhere in that proxy mobile IPv6 domain. From
the perspective of the mobile, the entire proxy mobile IPv6 domain
appears as a single link, the network ensures the mobile believes it
is always on the same link.
The mobile node can be operating in an IPv4-only mode, IPv6-only mode
or in dual IPv4/IPv6 mode. However, the specific details on how the
IPv4 network-based mobility management service is offered to the
mobile node is specified in the companion document, IPv4 Support for
Proxy Mobile IPv6 [ID-IPV4-PMIP6].
Typically, the configured policy in the network determines if the
mobile node is authorized for IPv6, IPv4 or IPv6/IPv4 home address
mobility. If the configured policy for a mobile node is for IPv6-
only home address mobility, the mobile node will be able to obtain
its IPv6 home address, any where in that Proxy Mobile IPv6 domain,
otherwise the 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 after it moves to
a new link.
7.1. Booting up in a Proxy Mobile IPv6 Domain Once a mobile node enters a Proxy Mobile IPv6 domain and attaches to
an access network, the mobile access gateway on the access link
detects the attachment of the mobile node and completes the binding
registration with the mobile node's local mobility anchor. If the
binding update operation is successfully performed, the mobile access
gateway will create the required state and setup the data path for
the mobile node's data traffic.
When a mobile node moves into a proxy mobile IPv6 domain and attaches If the mobile node is IPv6 enabled, on attaching to the access link,
to an access link, the mobile node will present its identity, MN- it will typically send Router Solicitation message [RFC-2461]. The
Identity, to the network as part of the access authentication mobile access gateway on the access link will respond to the Router
procedure. Once the authentication procedure is complete and the Solicitation message with a Router Advertisement. The Router
mobile node is authorized to access the network, the network or Advertisement will have the mobile node's home network prefix,
specifically the mobile access gateway on the access link will have default-router address and other address configuration parameters.
the mobile node's profile and so it would know the mobile node's home
network prefix and the permitted address configuration modes. The
mobile node's home network prefix may also be dynamically assigned by
the mobile node's local mobility anchor and the same may be learnt by
the mobile access gateway.
If the mobile node is IPv6 enabled, on attaching to the link and If the mobile access gateway on the access link, receives a Router
after access authentication, the mobile node typically would send a Solicitation message from the mobile node, before it completed the
Router Solicitation message. The mobile access gateway on the signaling with the mobile node's local mobility anchor, the mobile
attached link will respond to the Router Solicitation message with a access gateway may not know the mobile node's home network prefix and
Router Advertisement. The Router Advertisement will have the mobile may not be able to emulate the mobile node's home link on the access
node's home network prefix, default-router address and other address link. In such scenario, the mobile node may notice a slight delay
configuration parameters. The address configuration parameters such before it receives a Router Advertisement message.
as Managed Address Configuration, Stateful Configuration flag values
will typically be consistent through out that domain for that mobile
node.
If the Router Advertisement has the Managed Address Configuration If the received Router Advertisement has the Managed Address
flag set, the mobile node, as it would normally do, will send a Configuration flag set, the mobile node, as it would normally do,
DHCPv6 Request and the mobile access gateway on that access link will will send a DHCPv6 Request [RFC-3315]. The DHCP relay service
ensure, the mobile node gets an address from its home network prefix enabled on that access link will ensure the mobile node will obtain
as a lease from the DHCP server. its IPv6 address as a lease from its home network prefix.
If the Router Advertisement does not have the Managed Address If the received Router Advertisement does not have the Managed
Configuration flag set and if the mobile node is allowed to use an Address Configuration flag set and if the mobile node is allowed to
autoconfigured address, the mobile node will generate an interface use an autoconfigured address, the mobile node will be able to obtain
identifier, as per the Autoconf specification [RFC-2462] or using an IPv6 address using an interface identifier generated as per the
privacy extensions as specified in Privacy Extensions specification Autoconf specification [RFC-2462] or as per the Privacy Extensions
[RFC-3041]. specification [RFC-3041].
If the mobile node is IPv4 enabled or IPv4-only enabled, the mobile If the mobile node is IPv4 enabled and if the network permits, it
node after the access authentication, will be able to obtain the IPv4 will be able to obtain the IPv4 address configuration for the
address configuration for the connected interface by using DHCPv4. connected interface by using DHCP [RFC-2131]. The details related to
IPv4 support is specified in the companion document [ID-IPV4-PMIP6].
Once the address configuration is complete, the mobile node can Once the address configuration is complete, the mobile node can
continue to use the obtained address configuration as long as it is continue to use this address configuration as long as it is attached
with in the scope of that Proxy Mobile IPv6 domain. to the network that is 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 Domain
After booting in the Proxy Mobile IPv6 domain and obtaining the After obtaining the address configuration in the Proxy Mobile IPv6
address configuration, the mobile node as it roams in the network domain, as the mobile node moves and changes its point of attachment
between access links, will always detect its home network prefix on from one mobile access gateway to the other, it can still continue to
the link, as long as the attached access network is in the scope of use the same address configuration. As long as the attached access
that Proxy Mobile IPv6 domain. The mobile node can continue to use network is in the scope of that Proxy Mobile IPv6 domain, the mobile
its IPv4/IPv6 MN-HoA for sending and receiving packets. If the node will always detect the same link, where it obtained its initial
mobile node uses DHCP for address configuration, it will always be address configuration. If the mobile node performs DHCP operation,
able to obtain its MN-HoA using DHCP. However, the mobile node will it will always obtain the same address as before.
always detect a new default-router on each connected link, but still
advertising the mobile node's home network prefix as the on-link However, the mobile node will always detect a new default-router on
prefix and with the other configuration parameters consistent with each connected link, but still advertising the mobile node's home
its home link properties. network prefix as the on-link prefix and with the other configuration
parameters consistent with 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 does not require any changes to the mobile node's
with its protocol operation consistent with the base IPv6 IP stack. It assumes the mobile node to be a normal IPv4/IPv6 node,
specification [RFC-2460]. All aspects of Neighbor Discovery with its protocol operation consistent with the respective
Protocol, including Router Discovery, Neighbor Discovery, Address specifications.
Configuration procedures will just remain consistent with the base
IPv6 Neighbor Discovery Specification [RFC-2461]. However, this However, this specification recommends that the following IPv6
specification recommends that the following IPv6 operating parameters operating parameters on the mobile node be adjusted to the below
on the mobile node be adjusted to the below recommended values for recommended values for protocol efficiency and for achieving faster
protocol efficiency and for achieving faster hand-offs. hand-offs.
Lower Default-Router List Cache Time-out: Lower Default-Router List Cache Time-out:
As per the base IPv6 specification [RFC-2460], each IPv6 host will As per the base IPv6 specification [RFC-2461], each IPv6 host is
maintain certain host data structures including a Default-Router required to maintain certain host data structures including a
list. This is the list of on-link routers that have sent Router Default-Router list. This is the list of on-link routers that have
Advertisement messages and are eligible to be default routers on that sent Router Advertisement messages and are eligible to be default
link. The Router Lifetime field in the received Router Advertisement routers on that link. The Router Lifetime field in the received
defines the life of this entry. Router Advertisement defines the life of this entry.
In the Proxy Mobile IPv6 scenario, when the mobile node moves from In case of Proxy Mobile IPv6, when a mobile node moves from one link
one link to another, the received Router Advertisement messages to another, the source address of the received Router Advertisement
advertising the mobile's home network prefix will be from a different messages advertising the mobile node's home network prefix will be
link-local address and thus making the mobile node believe that there from a different link-local address and thus making the mobile node
is a new default-router on the link. It is important that the mobile believe that there is a new default-router on the link. It is
node uses the newly learnt default-router as supposed to the important that the mobile node uses the newly learnt default-router
previously learnt default-router. The mobile node must update its as supposed to the previously known default-router. The mobile node
default-router list with the new default router entry and must age must update its default-router list with the new default router entry
out the previously learnt default router entry from its cache, just and must age out the previously learnt default router entry from its
as specified in Section 6.3.5 of the base IPv6 ND specification [RFC- cache, just as specified in Section 6.3.5 [RFC-2461]. This action is
2461]. This action is critical for minimizing packet losses during a 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 default-router loss by performing the Neighbor
performing a Neighbor Unreachability Detection procedure, but it is Unreachability Detection procedure, but it is important that the
important that the mobile node times out the previous default router mobile node times out the previous default router entry at the
entry at the earliest. If a given IPv6 host implementation has the earliest. If a given IPv6 host implementation has the provision to
provision to adjust these flush timers, still conforming to the base adjust these flush timers, still conforming to the base IPv6 ND
IPv6 ND specification, it is desirable to keep the flush-timers to specification, it is desirable to keep the flush-timers to suit the
suit the above consideration. above consideration.
However, if the mobile access gateway has the ability to withdraw the In access network where SEND [RFC-3971] is not deployed, the mobile
previous default-router entry, by sending a Router Advertisement access gateway may withdraw the previous default-router entry, by
using the link-local address that of the previous mobile access sending a Router Advertisement using the link-local address that of
gateway and with the Router Lifetime field set to value 0, then it is the previous mobile access gateway and with the Router Lifetime field
possible to force the flush of the Previous Default-Router entry from set to value 0, then this will force the flush of the Previous
the mobile node's cache. This certainly requires some context- Default-Router entry from the mobile node's cache. This certainly
transfer mechanisms in place for notifying the link-local address of requires context-transfer mechanisms in place for notifying the link-
the default-router on the previous link to the mobile access gateway local address of the default-router on the previous link to the
on the new link. mobile access gateway 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 mobile access assignment of a unique link-local address for all the mobile access
gateways in a Proxy Mobile IPv6 domain. In any case, this is an gateways in a Proxy Mobile IPv6 domain and where SEND [RFC-3971] is
implementation choice and has no bearing on the protocol not deployed. In such scenario, the mobile node is not required to
interoperability. Implementations are free to adopt the best update the default-router entry. However, this is an implementation
approach that suits their target deployments. choice and has no bearing on the protocol interoperability.
Implementations are free to adopt the best 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
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sequence # | | Sequence # |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|A|H|L|K|M|R|P| Reserved | Lifetime | |A|H|L|K|M|R|P| Reserved | Lifetime |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | |
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 9: Proxy Binding Update Message Figure 11: Proxy Binding Update Message
A Binding Update message that is sent by mobile access gateway is
referred to as the Proxy Binding Update message. A Binding Update message that is sent by a mobile access gateway to a
local mobility anchor is referred to as the "Proxy Binding Update"
message. A new flag (P) is included in the Binding Update message.
The rest of the Binding Update message format remains the same as
defined in [RFC-3775].
Proxy Registration Flag (P) Proxy Registration Flag (P)
The Proxy Registration Flag is set to indicate to the local mobility A new flag (P) is included in the Binding Update message to indicate
anchor that the Binding Update is from a mobile access gateway acting to the local mobility anchor that the Binding Update message is a
as a proxy mobility agent. The flag MUST be set to the value of 1 proxy registration. The flag MUST be set to the value of 1 for proxy
for proxy registrations and MUST be set to 0 for direct registrations registrations and MUST be set to 0 for direct registrations sent by a
sent by a mobile node when using host-base mobility. mobile node.
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]. section 6.1.7 [RFC-3775].
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 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | |
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 10: Proxy Binding Acknowledgment Message Figure 12: Proxy Binding Acknowledgment Message
A Binding Acknowledgment message that is sent by the local mobility A Binding Acknowledgement message that is sent by a local mobility
anchor to the mobile access gateway is referred to as "Proxy Binding anchor to a mobile access gateway is referred to as the "Proxy
Acknowledgement". Binding Acknowledgement" message. A new flag (P) is included in the
Binding Acknowledgment message. The rest of the Binding
Acknowledgment message format remains the same as defined in [RFC-
3775].
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 that processed the indicate that the local mobility anchor that processed the
corresponding Proxy Binding Update message supports Proxy corresponding Proxy Binding Update message supports proxy
Registrations. The flag is set only if the corresponding Proxy registrations. The flag is set only if the corresponding Proxy
Binding Update had the Proxy Registration Flag (P) set to value of 1. Binding Update had the Proxy Registration Flag (P) set to value of 1.
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 section 6.1.8 of Mobile IPv6 specification [RFC3775]. the section 6.1.8 [RFC-3775].
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 Proxy Binding Acknowledgment messages
between the local mobility anchor and the mobile access gateway. exchanged between a local mobility anchor and a mobile access
This option can be used for exchanging the mobile node's home network gateway. This option is used for exchanging the mobile node's home
prefix information. network 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 40, line 24 skipping to change at page 43, line 24
| | | |
+ + + +
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type Type
<IANA> <IANA>
Length Length
8-bit unsigned integer indicating the length in octets of 8-bit unsigned integer indicating the length of the option
the option, excluding the type and length fields. This field in octets, excluding the type and length fields. This field
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. IPv6 prefix contained in the option.
Home Network Prefix Home Network Prefix
A sixteen-byte field containing the mobile node's IPv6 Home A sixteen-byte field containing the mobile node's IPv6 Home
Network Prefix. Network Prefix.
Figure 11: Home Network Prefix Option Figure 13: Home Network Prefix Option
8.4. Time Stamp Option 8.4. Link-local Address Option
A new option, Time Stamp Option is defined for use in the Proxy A new option, Link-local Address Option is defined for using it in
Binding Update and Acknowledgement messages. This option can be used the Proxy Binding Update and Proxy Binding Acknowledgment messages
in Proxy Binding Update and Proxy Binding Acknowledgement messages. exchanged between a local mobility anchor and a mobile access
gateway. This option is used for exchanging the mobile node's link-
local address.
The Link-local Address option has an alignment requirement of 8n+6.
Its format is as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ +
| |
+ Link-local Address +
| |
+ +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type
<IANA>
Length
8-bit unsigned integer indicating the length of the option
in octets, excluding the type and length fields. This field
MUST be set to 16.
Link-local Address
A sixteen-byte field containing the mobile node's link-local
address.
Figure 14: Link-local Address Option
8.5. Timestamp Option
A new option, Timestamp Option is defined for use in the Proxy
Binding Update and Proxy Binding Acknowledgement messages.
The Timestamp option has an alignment requirement of 8n+2. 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 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. The value
MUST be set to 8. for this field MUST be set to 8.
Timestamp Timestamp
64-bit time stamp A 64-bit unsigned integer field containing a timestamp. The value
indicates the number of seconds since January 1, 1970, 00:00 UTC,
by using a fixed point format. In this format, the integer number
of seconds is contained in the first 48 bits of the field, and the
remaining 16 bits indicate the number of 1/64K fractions of a
second.
Figure 12: Time Stamp Option Figure 15: Timestamp Option
8.5. Status Codes 8.6. Status Values
This document defines the following new Binding Acknowledgement This document defines the following new Status values for use in
status values: Proxy Binding Acknowledgment message. These values are to be
allocated from the same number space, as defined in Section 6.1.8
[RFC-3775].
145: Proxy Registration not supported by the local mobility anchor Status values less than 128 indicate that the Proxy Binding Update
was processed successfully by the local mobility anchor. Status
values greater than 128 indicate that the Proxy Binding Update was
rejected by the local mobility anchor.
146: Proxy Registrations from this mobile access gateway not allowed PROXY_REG_NOT_ENABLED:
147: Home Network prefix for this NAI is not configured and the Home Proxy Registration not enabled for the mobile node.
Network Prefix Option not present in the Proxy Binding Update.
148: Invalid Time Stamp Option in the received Proxy Binding Update MAG_NOT_AUTHORIZED_FOR_PROXY_REG:
The mobile access gateway is not authorized to send proxy binding.
updates.
NOT_AUTHORIZED_FOR_HOME_NETWORK_PREFIX
The mobile node is not authorized for the requesting home network
prefix.
TIMESTAMP_MISMATCH:
Invalid Timestamp value in the received Proxy Binding Update
message. message.
Status values less than 128 indicate that the Binding Update was MISSING_MN_IDENTIFIER_OPTION:
processed successfully by the receiving nodes. Values greater than
128 indicate that the Binding Update was rejected by the local
mobility anchor.
The value allocation for this usage needs to be approved by the IANA Missing mobile node identifier in the Proxy Binding Update
and must be updated in the IANA registry. message.
9. Protocol Configuration Variables 9. Protocol Configuration Variables
The mobile access gateway MUST allow the following variables to be The mobile access gateway MUST allow the following variables to be
configured by the system management. configured by the system management.
EnableMAGLocalrouting EnableMAGLocalrouting
This flag indicates whether or not the mobile access gateway is This flag indicates whether or not the mobile access gateway is
allowed to enable local routing of the traffic exchanged between a allowed to enable local routing of the traffic exchanged between a
visiting mobile node and a corresponding node that is locally visiting mobile node and a corresponding node that is locally
connected to one of the interfaces of the mobile access gateway. The connected to one of the interfaces of the mobile access gateway.
corresponding node can be another visiting mobile node as well, or a The corresponding node can be another visiting mobile node as
local fixed node. well, or a local fixed node.
The default value for this flag is set to "FALSE", indicating that The default value for this flag is set to "FALSE", indicating that
the mobile access gateway MUST reverse tunnel all the traffic to the the mobile access gateway MUST reverse tunnel all the traffic to
mobile node's local mobility anchor. the mobile node's local mobility anchor.
When the value of this flag is set to "TRUE", the mobile access When the value of this flag is set to "TRUE", the mobile access
gateway MUST route the traffic locally. gateway MUST route the traffic locally.
This aspect of local routing MAY be defined as policy on a per mobile This aspect of local routing MAY be defined as policy on a per
basis and when present will take precedence over this flag. mobile basis and when present will take precedence over this flag.
The local mobility anchor MUST allow the following variables to be
configured by the system management.
MinDelayBeforeBCEDelete
This variable specifies the amount of time in milli-seconds the
local mobility anchor MUST wait before it deletes a binding cache
entry of a mobile node, upon receiving a Proxy Binding Update
message from a mobile access gateway with a lifetime value of 0.
During this wait time, if the local mobility anchor receives a
Proxy Binding Update for the same mobile node, identified by its
MN-Identifier, with lifetime value greater than 0, then it must
update the binding cache entry with the accepted binding values.
At the end of this wait-time, if the local mobility anchor did not
receive any valid Proxy Binding Update message, it MUST delete the
binding cache entry for that mobile node.
The default value for this variable is 1000 milli-seconds.
10. IANA Considerations 10. IANA Considerations
This document defines a two new Mobility Header Options, the Home This document defines a three new Mobility Header Options, the Home
Network Prefix Option and the Time Stamp Option. These options are Network Prefix option, Link-local Address option and the Timestamp
described in Sections 8.3 and 8.5 respectively. The Type value for option. These options are described in Sections 8.3, 8.4 and 8.5
these options needs to be assigned from the same numbering space as respectively. The Type value for these options needs to be assigned
allocated for the other mobility options, as defined in [RFC-3775]. 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 8.6. The status values MUST be assigned from
the same space used for Binding Acknowledgement status values, as the same number space used for Binding Acknowledgement status values,
defined in [RFC-3775]. as defined in [RFC-3775]. The allocated values for each of these
status values MUST be greater than 128.
11. Security Considerations 11. Security Considerations
The potential security threats against any general network-based The potential security threats against any network-based mobility
mobility management protocol are covered in the document, Security management protocol are described in [RFC-4832]. This section
Threats to Network-Based Localized Mobility Management [RFC-4832]. explains how Proxy Mobile IPv6 protocol defends itself against those
This section analyses those vulnerabilities in the context of Proxy threats.
Mobile IPv6 protocol solution and covers all aspects around those
identified vulnerabilities.
A compromised mobile access gateway can potentially send Proxy Proxy Mobile IPv6 protocol requires the signaling messages, Proxy
Binding Update messages on behalf of the mobile nodes that are not Binding Update and Proxy Binding Acknowledgement, exchanged between
attached to its access link. This threat is similar to an attack on the mobile access gateway and the local mobility anchor to be
a typical routing protocol or equivalent to the compromise of an on- protected using IPsec, using the established security association
path router. This threat exists in the network today and this between them. This essentially eliminates the threats related to the
specification does not make this vulnerability any worse than what it impersonation of the mobile access gateway or the local mobility
is. However, to eliminate this vulnerability, the local mobility anchor.
anchor before accepting Proxy Binding Update message received from a
mobile access gateway, MUST ensure the mobile node is attached to the
mobile access gateway that sent the Proxy Binding Update message.
This can be achieved using out of band mechanisms and the specifics
of how that is achieved is beyond the scope of this document.
This document does not cover the security requirements for This specification allows a mobile access gateway to send binding
authorizing the mobile node for the use of the access link. It is registration messages on behalf of a mobile node. If proper
assumed that there are proper Layer-2/Layer-3 based authentication authorization checks are not in place, a malicious node may be able
procedures, such as EAP, are in place and will ensure the mobile node to hijack a mobile node's session or may do a denial-of-service
is properly identified and authorized before permitting it to access attacks. To prevent this attack, this specification requires the
the network. It is further assumed that the same security mechanism local mobility anchor to allow only authorized mobile access gateways
will ensure the mobile session is not hijacked by malicious nodes on to send binding registration messages on behalf of a mobile node.
the access link.
This specification requires that all the signaling messages exchanged To eliminate the threats on the interface between the mobile access
between the mobile access gateway and the local mobility anchor MUST gateway and the mobile node, this specification requires an
be authenticated by IPsec [RFC-4301]. The use of IPsec to protect established trust between the mobile access gateway and the mobile
Mobile IPv6 signaling messages is described in detail in the HA-MN node and to authenticate and authorize the mobile node before it is
IPsec specification [RFC-3776] and the applicability of that security allowed to access the network.
model to Proxy Mobile IPv6 protocol is covered in Section 4.0 of this
document.
As described in the base Mobile IPv6 specification [RFC-3775], both To eliminate the threats related to a compromised mobile access
the mobile node (in case of Proxy Mobile IPv6, its the mobile access gateway, this specification recommends that the local mobility anchor
gateway) and the local mobility anchor MUST support and SHOULD use before accepting a Proxy Binding Update message for a given mobile
the Encapsulating Security Payload (ESP) header in transport mode and node, to reasonably ensure, using some out of band mechanisms, that
MUST use a non-NULL payload authentication algorithm to provide data the given mobile node is attached to that mobile access gateway that
origin authentication, data integrity and optional anti-replay sent the request.
protection.
The proxy solution allows one device creating a routing state for The issues related to a compromised mobile access gateway in the
some other device at the local mobility anchor. It is important that scenario where the local mobility anchor and the mobile access
the local mobility anchor has proper authorization services in place gateway in different domains, is outside the scope of this document.
to ensure a given mobile access gateway is permitted to be a proxy This scenario is beyond the applicability of this document.
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
denial-of-service attacks.
12. 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, Ahmad Muhanna, JinHyeock Choi for Vogt, Pete McCann, Brian Haley, Ahmad Muhanna, JinHyeock Choi for
their thorough 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 Alex Petrescu, Alice Qinxia,
Weniger, Alex Petrescu, Mohamed Khalil, Fred Templing, Nishida Alper Yegin, Ashutosh Dutta, Behcet Sarikaya, Fred Templing, Genadi
Katsutoshi, James Kempf, Vidya Narayanan, Henrik Levkowetz, Phil Velev, George Tsirtsis, Gerardo Giaretta, Henrik Levkowetz, Hesham
Roberts, Jari Arkko, Ashutosh Dutta, Hesham Soliman, Behcet Sarikaya, Soliman, James Kempf, Jari Arkko, Jean-Michel Combes, John Zhao,
George Tsirtsis and many others for their passionate discussions in Jong-Hyouk Lee, Jonne Soininen, Jouni Korhonen, Kilian Weniger, Marco
the working group mailing list on the topic of localized mobility Liebsch, Mohamed Khalil, Nishida Katsutoshi, Phil Roberts, Ryuji
management solutions. These discussions stimulated much of the Wakikawa, Sangjin Jeong, Suresh Krishnan, Vidya Narayanan, Youn-Hee
thinking and shaped the draft to the current form. We acknowledge Han and many others for their passionate discussions in the working
that ! group mailing list on the topic of localized mobility management
solutions. These discussions stimulated much of the thinking and
shaped the draft to the current form. We acknowledge that !
The authors would also like to thank Ole Troan, Akiko Hattori, Parviz 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.
13. References 13. References
13.1. Normative References 13.1. Normative References
[RFC-1305] Mills, D., "Network Time Protocol (Version 3) [RFC-2030] Mills, D., "Simple Network Time Protocol (SNTP) Version 4
Specification, Implementation", RFC 1305, March 1992. for IPv4, IPv6 and OSI", RFC 2030, October 1996.
[RFC-2460] Deering, S. and R. Hinden, "Internet Protocol, Version 6 [RFC-2131] Droms, R., "Dynamic Host Configuration Protocol", RFC
(IPv6) Specification", RFC 2460, December 1998. 2131, March 1997.
[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.
[RFC-2462] Thompson, S., Narten, T., "IPv6 Stateless Address [RFC-2462] Thompson, S., Narten, T., "IPv6 Stateless Address
Autoconfiguration", RFC 2462, December 1998. Autoconfiguration", RFC 2462, December 1998.
[RFC-2473] Conta, A. and S. Deering, "Generic Packet Tunneling in [RFC-2473] Conta, A. and S. Deering, "Generic Packet Tunneling in
IPv6 Specification", RFC 2473, December 1998. IPv6 Specification", RFC 2473, December 1998.
skipping to change at page 45, line 7 skipping to change at page 49, line 46
M.Carney, "Dynamic Host Configuration Protocol for IPv6 (DHCPv6)", M.Carney, "Dynamic Host Configuration Protocol for IPv6 (DHCPv6)",
RFC 3315, July 2003. RFC 3315, July 2003.
[RFC-3775] Johnson, D., Perkins, C., Arkko, J., "Mobility Support in [RFC-3775] Johnson, D., Perkins, C., Arkko, J., "Mobility Support in
IPv6", RFC 3775, June 2004. IPv6", RFC 3775, June 2004.
[RFC-3776] Arkko, J., Devarapalli, V., and F. Dupont, "Using IPsec to [RFC-3776] Arkko, J., Devarapalli, V., and F. Dupont, "Using IPsec to
Protect Mobile IPv6 Signaling Between Mobile Nodes and Home Agents", Protect Mobile IPv6 Signaling Between Mobile Nodes and Home Agents",
RFC 3776, June 2004. RFC 3776, June 2004.
[RFC4282] Aboba, B., Beadles, M., Arkko, J., and P. Eronen, "The
Network Access Identifier", RFC 4282, November 2005.
[RFC-4283] Patel, A., Leung, K., Khalil, M., Akhtar, H., and K. [RFC-4283] Patel, A., Leung, K., Khalil, M., Akhtar, H., and K.
Chowdhury, "Mobile Node Identifier Option for Mobile IPv6", RFC 4283, Chowdhury, "Mobile Node Identifier Option for Mobile IPv6", RFC 4283,
November 2005. November 2005.
[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.
skipping to change at page 45, line 31 skipping to change at page 50, line 26
G., Liebsch, M., "Problem Statement for Network-based Localized G., Liebsch, M., "Problem Statement for Network-based Localized
Mobility Management", September 2006. Mobility Management", September 2006.
[RFC-4831] Kempf, J., Leung, K., Roberts, P., Nishida, K., Giaretta, [RFC-4831] Kempf, J., Leung, K., Roberts, P., Nishida, K., Giaretta,
G., Liebsch, M., "Goals for Network-based Localized Mobility G., Liebsch, M., "Goals for Network-based Localized Mobility
Management", October 2006. Management", October 2006.
[RFC-4832] Vogt, C., Kempf, J., "Security Threats to Network-Based [RFC-4832] Vogt, C., Kempf, J., "Security Threats to Network-Based
Localized Mobility Management", September 2006. Localized Mobility Management", September 2006.
[ID-IPV4-PMIP6] Wakikawa, R. and Gundavelli, S., "IPv4 Support for [RFC-4877] Devarapalli, V. and Dupont, F., "Mobile IPv6 Operation
Proxy Mobile IPv6", draft-ietf-netlmm-pmip6-ipv4-support-00.txt, May with IKEv2 and the revised IPsec Architecture", RFC 4877, April 2007.
2007.
[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 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
skipping to change at page 46, line 14 skipping to change at page 51, line 5
[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.
[ID-IPV4-PMIP6] Wakikawa, R. and Gundavelli, S., "IPv4 Support for
Proxy Mobile IPv6", draft-ietf-netlmm-pmip6-ipv4-support-00.txt, May
2007.
[ID-DNAV6] Kempf, J., et al "Detecting Network Attachment in IPv6 [ID-DNAV6] Kempf, J., et al "Detecting Network Attachment in IPv6
Networks (DNAv6)", draft-ietf-dna-protocol-03.txt, October 2006. Networks (DNAv6)", draft-ietf-dna-protocol-03.txt, October 2006.
[ID-MIP6-IKEV2] Devarapalli, V. and Dupont, F., "Mobile IPv6 [ID-MN-AR-INTERFACE] Laganier, J. and Narayanan, S., "Network-based
Operation with IKEv2 and the revised IPsec Architecture", Localized Mobility Management Interface between Mobile Node and
draft-ietf-mip6-ikev2-ipsec-08.txt, December 2006. Mobility Access Gateway", draft-ietf-netlmm-mn-ar-if-02.txt, May
2007.
[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.
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
is dynamically allocated for the mobile node when it boots up for the is dynamically allocated for the mobile node when it boots up for the
first time in the network, or it could be a statically configured first time in the network, or it could be a statically configured
value on per mobile node basis. However, for all practical purposes, value on per mobile node basis. However, for all practical purposes,
the network entities in the proxy Mobile IPv6 domain, while serving a the network entities in the proxy Mobile IPv6 domain, while serving a
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 This specification supports Per-MN-Prefix model. However, it is
configured with a common IPv6 network prefix, as in Mobile IPv6 possible to support Shared-Prefix model under the following
specification, it is possible to support that configuration under the guidelines.
following guidelines:
The mobile node is allowed to use stateful 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 node 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 [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 For all IPv6 traffic from the source MN-HoA::/128 to
_ANY_DESTINATION_, route via tunnel0, next-hop LMAA, where tunnel0 is _ANY_DESTINATION_, route via tunnel0, next-hop LMAA, where tunnel0 is
the MAG to LMA tunnel. the MAG to LMA tunnel.
Routing state at the local mobility anchor: Routing state at the local mobility anchor:
 End of changes. 229 change blocks. 
1058 lines changed or deleted 1246 lines changed or added

This html diff was produced by rfcdiff 1.34. The latest version is available from http://tools.ietf.org/tools/rfcdiff/