draft-ietf-mip4-nemo-v4-base-08.txt   draft-ietf-mip4-nemo-v4-base-09.txt 
MIP4 K. Leung MIP4 K. Leung
Internet-Draft G. Dommety Internet-Draft G. Dommety
Intended status: Standards Track Cisco Systems Intended status: Standards Track Cisco Systems
Expires: July 24, 2008 V. Narayanan Expires: August 20, 2008 V. Narayanan
Qualcomm, Inc. Qualcomm, Inc.
A. Petrescu A. Petrescu
Motorola Motorola
January 21, 2008 February 17, 2008
Network Mobility (NEMO) Extensions for Mobile IPv4 Network Mobility (NEMO) Extensions for Mobile IPv4
draft-ietf-mip4-nemo-v4-base-08.txt draft-ietf-mip4-nemo-v4-base-09.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 38 skipping to change at page 1, line 38
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
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This Internet-Draft will expire on July 24, 2008. This Internet-Draft will expire on August 20, 2008.
Copyright Notice Copyright Notice
Copyright (C) The IETF Trust (2008). Copyright (C) The IETF Trust (2008).
Abstract Abstract
This document describes a protocol for supporting Mobile Networks This document describes a protocol for supporting Mobile Networks
between a Mobile Router and a Home Agent by extending the Mobile IPv4 between a Mobile Router and a Home Agent by extending the Mobile IPv4
protocol. A Mobile Router is responsible for the mobility of one or protocol. A Mobile Router is responsible for the mobility of one or
more network segments or subnets moving together. The Mobile Router more network segments or subnets moving together. The Mobile Router
hides its mobility from the nodes on the mobile network. The nodes hides its mobility from the nodes on the mobile network. The nodes
on the Mobile Network may be fixed in relationship to the Mobile on the Mobile Network may be fixed in relationship to the Mobile
Router and may not have any mobility function. Router and may not have any mobility function.
Extensions to Mobile IPv4 are introduced to support Mobile Networks. Extensions to Mobile IPv4 are introduced to support Mobile Networks.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 1.1. Examples of Mobile Networks . . . . . . . . . . . . . . . 3
3. Requirements . . . . . . . . . . . . . . . . . . . . . . . . . 4 1.2. Overview of Protocol . . . . . . . . . . . . . . . . . . . 4
4. Mobile Network Extensions . . . . . . . . . . . . . . . . . . 5 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 6
4.1. Mobile Network Request Extension . . . . . . . . . . . . . 5 3. Requirements . . . . . . . . . . . . . . . . . . . . . . . . . 7
4.2. Mobile Network Acknowledgement Extension . . . . . . . . . 6 4. Mobile Network Extensions . . . . . . . . . . . . . . . . . . 8
5. Mobile Router Operation . . . . . . . . . . . . . . . . . . . 8 4.1. Representing a Subnet . . . . . . . . . . . . . . . . . . 8
5.1. Error Processing . . . . . . . . . . . . . . . . . . . . . 9 4.2. Mobile Network Request Extension . . . . . . . . . . . . . 9
6. Home Agent Operation . . . . . . . . . . . . . . . . . . . . . 9 4.3. Mobile Network Acknowledgement Extension . . . . . . . . . 10
6.1. Summary . . . . . . . . . . . . . . . . . . . . . . . . . 9 5. Mobile Router Operation . . . . . . . . . . . . . . . . . . . 13
6.2. Data Structures . . . . . . . . . . . . . . . . . . . . . 10 5.1. Error Processing . . . . . . . . . . . . . . . . . . . . . 14
6.2.1. Registration Table . . . . . . . . . . . . . . . . . . 10 5.2. Mobile Router Management . . . . . . . . . . . . . . . . . 14
6.2.2. Prefix Table . . . . . . . . . . . . . . . . . . . . . 11 6. Home Agent Operation . . . . . . . . . . . . . . . . . . . . . 15
6.3. Mobile Network Prefix Registration . . . . . . . . . . . . 11 6.1. Summary . . . . . . . . . . . . . . . . . . . . . . . . . 15
6.4. Advertising Mobile Network Reachability . . . . . . . . . 12 6.2. Data Structures . . . . . . . . . . . . . . . . . . . . . 16
6.5. Establishment of Bi-directional Tunnel . . . . . . . . . . 13 6.2.1. Registration Table . . . . . . . . . . . . . . . . . . 16
6.6. Sending Registration Replies . . . . . . . . . . . . . . . 13 6.2.2. Prefix Table . . . . . . . . . . . . . . . . . . . . . 16
6.7. Mobile Network Prefix De-registration . . . . . . . . . . 13 6.3. Mobile Network Prefix Registration . . . . . . . . . . . . 16
7. Data Forwarding Operation . . . . . . . . . . . . . . . . . . 14 6.4. Advertising Mobile Network Reachability . . . . . . . . . 18
8. Nested Mobile Networks . . . . . . . . . . . . . . . . . . . . 14 6.5. Establishment of Bi-directional Tunnel . . . . . . . . . . 18
9. Routing Protocol between Mobile Router and Home Agent . . . . 15 6.6. Sending Registration Replies . . . . . . . . . . . . . . . 18
10. Security Considerations . . . . . . . . . . . . . . . . . . . 16 6.7. Mobile Network Prefix De-registration . . . . . . . . . . 19
10.1. Security when Dynamic Routing Protocol is Used . . . . . . 17 7. Data Forwarding Operation . . . . . . . . . . . . . . . . . . 19
11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 17 8. Nested Mobile Networks . . . . . . . . . . . . . . . . . . . . 20
12. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 19 9. Routing Protocol between Mobile Router and Home Agent . . . . 20
13. References . . . . . . . . . . . . . . . . . . . . . . . . . . 19 10. Security Considerations . . . . . . . . . . . . . . . . . . . 21
13.1. Normative References . . . . . . . . . . . . . . . . . . . 19 10.1. Security when Dynamic Routing Protocol is Used . . . . . . 22
13.2. Informative References . . . . . . . . . . . . . . . . . . 19 11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 22
Appendix A. ChangeLog . . . . . . . . . . . . . . . . . . . . . . 20 12. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 24
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 23 13. References . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Intellectual Property and Copyright Statements . . . . . . . . . . 25 13.1. Normative References . . . . . . . . . . . . . . . . . . . 25
13.2. Informative References . . . . . . . . . . . . . . . . . . 26
Appendix A. ChangeLog . . . . . . . . . . . . . . . . . . . . . . 26
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 30
Intellectual Property and Copyright Statements . . . . . . . . . . 32
1. Introduction 1. Introduction
This document describes protocol extensions to Mobile IPv4 as per This document describes network mobility extensions to the Mobile
RFC 3344 [RFC3344] and its update [I-D.ietf-mip4-rfc3344bis], to IPv4 protocol. The goal of introducing these extensions is to
enable support for Mobile Networks. This draft addresses mainly the acommodate mobility scenarios where groups of hosts and routers move
co-located Care-of Address mode. Foreign Agent Care-of Address mode homogeneously (as a whole). It is required that all hosts and
(with 'legacy' Foreign Agents, RFC 3344 [RFC3344]) are supported but routers in a mobile network be able to run applications connecting to
without optimization, double encapsulation being used. For an the Internet, and to be reachable from the Internet.
optimization of this mode, the gentle reader is directed to an
extension document [I-D.ietf-mip4-nemov4-fa].
A Mobile Network is defined as a network segment or subnet that can For details regarding terminology related to network mobility (NEMO),
change its point of attachment to the routing infrastructure. Such the gentle reader is suggested a quick read of RFC 4885 [RFC4885].
movement is performed by a Mobile Router, which is the mobility
entity that provides connectivity and reachability as well as session
continuity for all the nodes in the Mobile Network. The Mobile
Router typically serves as the default gateway for the hosts on the
Mobile Network.
Mobility for the Mobile Network is supported by the Mobile Router 1.1. Examples of Mobile Networks
registering the point of attachment to its Home Agent. This
signaling sets up the tunnel between the two entities.
The Mobile Networks (either implicitly configured on the Home Agent A mobile network links together a set of hosts and routers.
or explicitly identified by the Mobile Router) are advertised by the Connecting this mobile network to the Internet is ensured at two
Home Agent for route propagation. Traffic to and from nodes in the levels: first, a Mobile Router is connected on one side to the Mobile
Mobile Network are tunneled by the Home Agent to the Mobile Router, Network and on another side to a wireless access system; second, a
and vice versa. Though packets from the Mobile Network can be Home Agent placed on the home link manages traffic between the
forwarded directly without tunneling (if reverse tunneling is not Correspondent Node and a Local Fixed Node (LFN, a node in the mobile
used) packets will be dropped if ingress filtering is turned on. network) by means of encapsulating traffic.
This document specifies an additional tunnel between a Mobile A scenario of applicability for this mobile network is described
Router's Home Address and the Home Agent. This tunnel is next. A mobile network is formed by a wireless-enabled Personal
encapsulated within the normal tunnel between the Care-of Address Digital Assistant (PDA) and a portable photographic camera, linked
(CoA) and Home Agent. In Foreign Agent CoA mode, the tunnel between together by Bluetooth wireless link-layer technology. This is
the Mobile Router and Home Agent is needed to allow the Foreign Agent sometimes referred to as a Personal Area Network (PAN). In the
to direct the decapsulated packet to the proper visiting Mobile illustration below one can notice the PDA playing the role of a
Router. However, in Collocated CoA mode, the additional tunnel is Mobile Router and the camera the role of Local Fixed Node:
not essential and could be eliminated because the Mobile Router is
the recipient of the encapsulated packets for the Mobile Network; a ----
proposal for this feature is in an extension document | HA |
---- --------
| / \ ----
-+--------| Internet |---------| CN |
\ / ----
--------
/ \
/ \
/ \
---- ----
| AR | | AR |
---- ----
|cellular |cellular
/ |cellular
| ---- ----
Mobile | | MR | |LFN | ---movement-->
Network < ---- ----
| | |
| -+-----------+-
\ Bluetooth
The camera (Local Fixed Node) uploads photographic content to a
Correspondent Node (CN) server. When the mobile network moves away,
the Mobile Router serving the mobile network changes its point of
attachment from one cellular access (Access Router) to another,
obtaining a new Care-of Address. The Home Agent (HA) encapsulates
application traffic for CN and LFN.
Whereas the illustration above is a very simple instantiation of the
applicability of Mobile IP-based mobile networks, more complex mobile
networks are easily acommodated by the Mobile IPv4 extensions
presented in this document (NEMOv4). For example, laptop computers
used by passengers in a bus, train, ship or in a plane should all be
considered as forming mobile networks, as long as they move together
(homogeneously).
1.2. Overview of Protocol
As introduced previously, this document presents extensions to the
Mobile IPv4 protocol. The entities sending and receiving these
extensions are the Mobile Router and the Home Agent. The Local Fixed
Node is relieved from running Mobile IP software and, although it
moves (together with the mobile network), its IP stack is not seing
any change in addressing.
Mobility for the entire Mobile Network is supported by the Mobile
Router registering its current point of attachment (Care-of Address)
to its Home Agent: Mobile Router sends an extended Registration
Request to Home Agent which returns an extended Registration Reply.
This signaling sets up the tunnel between the two entities, as
illustrated in the following figure:
LFN MR HA CN
| | | |
| | Extended Registration | |
| |---------------------->| |
| | Request | |
| | | |
| | | |
| | Extended Registration | |
| |<----------------------| |
| | Reply | |
| | | |
|<--------o=======================o-------->|
| | Encapsulated | |
| | Application Traffic | |
| | | |
The prefix(es) used within a Mobile Network (either implicitly
configured on the Home Agent or explicitly identified by the Mobile
Router in the Registration Request) is/are advertised by the Home
Agent for route propagation in the home network. Traffic to and from
nodes in the Mobile Network are tunelled by the Home Agent to the
Mobile Router, and vice versa. Though packets from a Local Fixed
Node placed in the Mobile Network can be forwarded by the Mobile
Router directly without tunneling (if reverse tunneling were not
used) these packets will be dropped if ingress filtering is turned on
at the Access Router.
Extensively relating to Mobile IPv4 RFC 3344 [RFC3344], this
specification addresses mainly the co-located Care-of Address mode.
Foreign Agent Care-of Address mode (with 'legacy' Foreign Agents,
RFC 3344 [RFC3344]) are supported but without optimization, double
encapsulation being used. For an optimization of this mode, the
gentle reader is directed to an extension document
[I-D.ietf-mip4-nemov4-fa]. [I-D.ietf-mip4-nemov4-fa].
Compared to Mobile IPv4, this document specifies an additional tunnel
between a Mobile Router's Home Address and the Home Agent. This
tunnel is encapsulated within the normal tunnel between the Care-of
Address (CoA) and Home Agent. In Foreign Agent CoA mode, the tunnel
between the Mobile Router and Home Agent is needed to allow the
Foreign Agent to direct the decapsulated packet to the proper
visiting Mobile Router. However, in Collocated CoA mode, the
additional tunnel is not essential and could be eliminated because
the Mobile Router is the recipient of the encapsulated packets for
the Mobile Network; a proposal for this feature is in a further
extending document [I-D.ietf-mip4-nemov4-fa].
All traffic between the nodes in the Mobile Network and Correspondent All traffic between the nodes in the Mobile Network and Correspondent
Nodes passes through the Home Agent. This document does not cover Nodes passes through the Home Agent. This document does not touch on
route optimization of this traffic. aspects related to route optimization of this traffic.
A similar protocol has been documented in RFC 3963 [RFC3963] for A similar protocol has been documented in RFC 3963 [RFC3963] for
supporting IPv6 mobile networks with Mobile IPv6 extensions. supporting IPv6 mobile networks with Mobile IPv6 extensions.
Multihoming for Mobile Routers is outside the scope of this document. Multihoming for Mobile Routers is outside the scope of this document.
2. Terminology 2. Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119]. document are to be interpreted as described in RFC 2119 [RFC2119].
Terminology for network mobility support is defined in RFC 3344 Terminology for Mobile IPv4 mobility support is defined in RFC 3344
[RFC3344] and its update [I-D.ietf-mip4-rfc3344bis]. In addition, [RFC3344]. Terminology for network mobility support (NEMO), from an
this document defines the following terms. IPv6 perspective, is described in RFC 4885 [RFC4885]. In addition,
this document defines the following terms for NEMOv4.
Mobile Router
RFC 3344 [RFC3344] defines a Mobile Router as a mobile node
that can be a router that is responsible for the mobility of
one or more entire networks moving together, perhaps on an
airplane, a ship, a train, an automobile, a bicycle, or a
kayak.
Mobile Network Prefix Mobile Network Prefix
The network prefix of the subnet delegated to a Mobile Router The network prefix of the subnet delegated to a Mobile Router
as the Mobile Network. as the Mobile Network.
Prefix Table Prefix Table
A list of Mobile Network Prefixes indexed by the Home Address A list of Mobile Network Prefixes indexed by the Home Address
of a Mobile Router. The Home Agent manages and uses Prefix of a Mobile Router. The Home Agent manages and uses Prefix
Table to determine which Mobile Network Prefixes belong to a Table to determine which Mobile Network Prefixes belong to a
particular Mobile Router. particular Mobile Router.
Local Fixed Node
RFC 4885 [RFC4885] defines a Local Fixed Node (LFN) to be a
fixed node belonging to the mobile network and unable to
change its point of attachment. This definition should not
be confused with "Long, Fat Network, LFN" of RFC 1323
[RFC1323], at least because this latter is pronounced
"elephan(t)" whereas a NEMO LFN is distinctively pronounced
"elefen".
3. Requirements 3. Requirements
Although the original Mobile IPv4 specifications stated that Mobile Although the original Mobile IPv4 specifications stated that Mobile
Networks can be supported by the Mobile Router and Home Agent using Networks can be supported by the Mobile Router and Home Agent using
static configuration or running a routing protocol (see Section 4.5 static configuration or running a routing protocol (see Section 4.5
of RFC 3344 [RFC3344]), there is no solution for explicit of RFC 3344 [RFC3344]), there is no solution for explicit
registration of the Mobile Networks served by the Mobile Router. A registration of the Mobile Networks served by the Mobile Router. A
solution needs to provide the Home Agent a means to ensure that a solution needs to provide the Home Agent a means to ensure that a
Mobile Router claiming a certain Mobile Network Prefix is authorized Mobile Router claiming a certain Mobile Network Prefix is authorized
to do so. A solution would also expose the Mobile Network Prefixes to do so. A solution would also expose the Mobile Network Prefixes
skipping to change at page 5, line 15 skipping to change at page 8, line 5
from the AAA server, via pre-configuration, or via a dynamic from the AAA server, via pre-configuration, or via a dynamic
routing protocol. routing protocol.
o The Mobile Network should be supported using Foreign Agents that o The Mobile Network should be supported using Foreign Agents that
are compliant to RFC 3344 [RFC3344] without any changes ('legacy' are compliant to RFC 3344 [RFC3344] without any changes ('legacy'
Foreign Agents). Foreign Agents).
o The mobile network should allow Fixed Nodes, Mobile Nodes, or o The mobile network should allow Fixed Nodes, Mobile Nodes, or
Mobile Routers to be on it. Mobile Routers to be on it.
o The Local Fixed Nodes on a mobile network should be able to
execute their sessions without running themselves Mobile IP
stacks. The Mobile Router managing the LFNs' mobile network is
'hiding' mobility events like the changes of the Care-of Address
from the Local Fixed Nodes in that mobile network.
4. Mobile Network Extensions 4. Mobile Network Extensions
4.1. Mobile Network Request Extension 4.1. Representing a Subnet
Since the protocol extensions presented in this document concentrate
on treatment of prefixes, subnets and network masks it is important
to choose an all-encompassing wire representation of subnets, as
generic as possible.
A subnet can easily be represented as address/prefix length, as in
192.168.1.1/24. This is interpreted as the subnet being the first
leftmost 24 bits of the address 192.168.1.1, i.e. 192.168.1. This
representation corresponds to an underlying forwarding system which
uses longest-prefix match rules. It is typically in widespread
deployment in the Internet.
In a Mobile Network Extension, this representation is expressed by
the tuple of Prefix and Prefix Length fields.
On another hand, some forwarding systems don't use longest-prefix
match rules. In these cases it is important to provide the more
generic way of representing subnets by using non-contiguous sets of
1bits as netmasks. For example, 255.255.0.255 is a perfectly legal
netmask which, when applied to an address like 192.168.1.1 gives the
network part 192.168.x.1, the third 'x' byte acting alone as the host
part.
In a Mobile Network Extension, this non-contiguous netmask
representation is expressed by the tuple of Prefix and Optional
Netmask fields (Prefix Length field being ignored).
The two representation methods (address/prefix and address/netmask)
are alternative and only one method of representation is used by a
Mobile Network Extension.
Representing the subnet as address/prefix has the advantage of a more
compact encoding (40bits) whereas the address/netmask requires
64bits. Hence it is suggested as a default. However, representing
the subnet as address/netmask gives more applicability of NEMOv4
extensions to forwarding systems where more complex forwarding
schemes are used.
4.2. Mobile Network Request Extension
For Explicit Mode, the Mobile Router informs the Home Agent about the For Explicit Mode, the Mobile Router informs the Home Agent about the
Mobile Network Prefixes during registration. The Registration Mobile Network Prefixes during registration. The Registration
Request contains zero, one or several Mobile Network Request Request contains zero, one or several Mobile Network Request
extensions in addition to any other extensions defined by or in the extensions in addition to any other extensions defined by or in the
context of RFC 3344 [RFC3344]. When several Mobile Networks are context of RFC 3344 [RFC3344]. When several Mobile Networks are
needed to be registered, each is included in a separate Mobile needed to be registered, each is included in a separate Mobile
Network Request extension, with its own Type, Length, Sub-Type, Network Request extension, with its own Type, Length, Sub-Type,
Prefix Length and Prefix fields. A Mobile Network Request extension Prefix Length, Prefix and optionally the Optional Netmask fields.
is encoded in Type-Length-Value (TLV) format and respects the For a discussion of the subnet encoding see Section 4.1. A Mobile
following format: Network Request extension is encoded in Type-Length-Value (TLV)
format and respects the following ordering:
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 | Sub-Type | Prefix Length | | Type | Length | Sub-Type | Prefix Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Prefix | | Prefix |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Optional Netmask |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type: Type:
Mobile Network Extension (skippable type range to be assigned Mobile Network Extension (skippable type range to be assigned
by IANA). by IANA).
Length: Length:
6 Decimal 6 or decimal 10, not any other. If the masking is
expressed as Prefix/Prefix Length (e.g. 192.168.1.1/24), the
value of this Length field is decimal 6 and the Optional
Netmask field is absent. If the masking is expressed as
Prefix and Netmask (e.g. 192.168.1.1 255.255.0.255) then the
value of this Length field is decimal 10, the Optional
Netmask field is present and the value of the Prefix Length
field is set to all-zero by sender and ignored by receiver.
Sub-Type: Sub-Type:
TBA (Mobile Network Request) TBA (Mobile Network Request)
Prefix Length: Prefix Length:
8-bit unsigned integer indicating the number of bits covering 8-bit unsigned integer indicating the number of leftmost bits
the network part of the address contained in the Prefix covering the network part of the address contained in the
field. Prefix field. If the Optional Netmask field is present then
this field is set to all-zero by sender and ignored by
receiver.
Prefix: Prefix:
32-bit unsigned integer in network byte-order containing an 32-bit unsigned integer in network byte-order containing an
IPv4 address whose first Prefix Length bits make up the IPv4 address. If the Optional Netmask field is absent then
Mobile Network Prefix. the first Prefix Length bits make up the Mobile Network
Prefix. Otherwise the Mobile Network Prefix is obtained by
masking this IPv4 address with the value of the Optional
Netmask field.
4.2. Mobile Network Acknowledgement Extension Optional Netmask:
32-bit unsigned integer in network byte-order containing an
IPv4 netmask. For example '255.255.0.255'. This field is
present when the subnet masking needs to be expressed as a
non-contiguous set of 1 bits. Otherwise it is absent. If
the Optional Netmask is present then the value of the field
Prefix Length is set to all-zero by sender and ignored by
receiver.
4.3. Mobile Network Acknowledgement Extension
The Registration Reply contains zero, one or several Mobile Network The Registration Reply contains zero, one or several Mobile Network
Acknowledgement extensions in addition to any other extensions Acknowledgement extensions in addition to any other extensions
defined by or in the context of RFC 3344 [RFC3344] and its update defined by or in the context of RFC 3344 [RFC3344]. For Implicit
[I-D.ietf-mip4-rfc3344bis]. For Implicit Mode, the Mobile Network Mode, the Mobile Network Acknowledgement informs the Mobile Router
Acknowledgement informs the Mobile Router the prefixes for which the the prefixes for which the Home Agent sets up forwarding with respect
Home Agent sets up forwarding with respect to this Mobile Router. to this Mobile Router. Policies such as permitting only traffic from
Policies such as permitting only traffic from these Mobile Networks these Mobile Networks to be tunneled to the Home Agent may be applied
to be tunneled to the Home Agent may be applied by the Mobile Router. by the Mobile Router. For Explicit Mode, when several Mobile
For Explicit Mode, when several Mobile Networks are needed to be Networks are needed to be acknowledged explicitly, each is included
acknowledged explicitly, each is included in a separate Mobile in a separate Mobile Network Acknowledgement extension, with its own
Network Acknowledgement extension, with its own Type, Sub-Type, Type, Sub-Type, Length, Prefix, Prefix Length and optionally the
Length and Prefix Length fields. At least one Mobile Network Optional Netmask fields. For a discussion of the subnet encoding see
Acknowledgement extension MUST be in a successful Registration Reply Section 4.1. At least one Mobile Network Acknowledgement extension
to indicate to the Mobile Router that the Mobile Network Request MUST be in a successful Registration Reply to indicate to the Mobile
extension was processed, thereby not skipped by the Home Agent. Router that the Mobile Network Request extension was processed,
thereby not skipped by the Home Agent.
A Registration Reply may contain any non-zero number of Explicit Mode A Registration Reply may contain any non-zero number of Explicit Mode
and Implicit Mode Acknowledgements sub-types. Both sub-types can be and Implicit Mode Acknowledgements sub-types. Both sub-types can be
present in a single Registration Reply. A Mobile Network present in a single Registration Reply. A Mobile Network
Acknowledgement extension is encoded in Type-Length-Value (TLV) Acknowledgement extension is encoded in Type-Length-Value (TLV)
format. When the registration is denied with code HA_MOBNET_ERROR, format. When the registration is denied with Code HA_MOBNET_ERROR
the Code field in the extension provides the reason for the failure. (Code field in the Registration Reply), the Code field in the
included Mobile Network Extension provides the reason for the
failure.
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 | Sub-Type | Code | | Type | Length | Sub-Type | Code |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Prefix Length | Reserved | Prefix | Prefix Length | Reserved | Prefix...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ...Prefix | Optional Netmask...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
...Optional Netmask |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type: Type:
TBA Mobile Network Extension (skippable type range to be TBA Mobile Network Extension (skippable type range to be
assigned by IANA). assigned by IANA).
Length: Length:
8 Decimal 8 or decimal 12, not any other. If the masking is
expressed as Prefix/Prefix Length (e.g. 192.168.1.1/24), the
value of this Length field is decimal 8 and the Optional
Netmask field is absent. If the masking is expressed as
Prefix and Netmask (e.g. 192.168.1.1 255.255.0.255) then the
value of this Length field is decimal 12, the Optional
Netmask field is present and the value of the Prefix Length
field set to all-zero by sender and ignored by receiver.
Sub-Type: Sub-Type:
TBA (Explicit Mode Acknowledgement) TBA (Explicit Mode Acknowledgement)
TBA (Implicit Mode Acknowledgement) TBA (Implicit Mode Acknowledgement)
Code: Code:
Value indicating success or failure: Value indicating success or failure:
skipping to change at page 7, line 45 skipping to change at page 12, line 24
TBA Invalid prefix (MOBNET_INVALID_PREFIX_LEN) TBA Invalid prefix (MOBNET_INVALID_PREFIX_LEN)
TBA Mobile Router is not authorized for prefix TBA Mobile Router is not authorized for prefix
(MOBNET_UNAUTHORIZED) (MOBNET_UNAUTHORIZED)
TBA Forwarding setup failed (MOBNET_FWDING_SETUP_FAILED) TBA Forwarding setup failed (MOBNET_FWDING_SETUP_FAILED)
Prefix Length: Prefix Length:
8-bit unsigned integer indicating the number of bits covering 8-bit unsigned integer indicating the number of leftmost bits
the network part of the address contained in the Prefix covering the network part of the address contained in the
field. Prefix field. If the Optional Netmask field is present then
this field is set to all-zero by sender and ignored by
receiver.
Reserved: Reserved:
Sent as zero; ignored on reception. Sent as zero; ignored on reception.
Prefix: Prefix:
32-bit unsigned integer in network byte-order containing an 32-bit unsigned integer in network byte-order containing an
IPv4 address whose first Prefix Length bits make up the IPv4 address. If the Optional Netmask field is absent then
Mobile Network Prefix. the first Prefix Length bits make up the Mobile Network
Prefix. Otherwise the Mobile Network Prefix is obtained by
masking this IPv4 address with the value of the Optional
Netmask field.
Optional Netmask:
32-bit unsigned integer in network byte-order containing an
IPv4 netmask. For example '255.255.0.255'. This field is
present when the subnet masking needs to be expressed as a
non-contiguous set of 1 bits. Otherwise it is absent. If
the Optional Netmask is present then the value of the field
Prefix Length is set to all-zero by sender and ignored by
receiver.
5. Mobile Router Operation 5. Mobile Router Operation
A Mobile Router's operation is generally derived from the behavior of A Mobile Router's operation is generally derived from the behavior of
a Mobile Node, as set in RFC 3344 [RFC3344] and its update a Mobile Node, as set in RFC 3344 [RFC3344]. In addition to
[I-D.ietf-mip4-rfc3344bis]. In addition to maintaining mobility maintaining mobility bindings for its Home Address, the Mobile
bindings for its Home Address, the Mobile Router, together with the Router, together with the Home Agent, maintains forwarding
Home Agent, maintains forwarding information for the Mobile Network information for the Mobile Network Prefix(es) assigned to the Mobile
Prefix(es) assigned to the Mobile Router. Router.
A Mobile Router SHOULD set the 'T' bit to 1 in all Registration A Mobile Router SHOULD set the 'T' bit to 1 in all Registration
Request messages it sends to indicate the need for reverse tunnels Request messages it sends to indicate the need for reverse tunnels
for all traffic. Without reverse tunnels, all the traffic from the for all traffic. Without reverse tunnels, all the traffic from the
mobile network will be subject to ingress filtering in the visited mobile network will be subject to ingress filtering in the visited
networks. Upon reception of a successful Registration Reply, the networks. Upon reception of a successful Registration Reply, the
Mobile Router processes the registration in accordance to RFC 3344 Mobile Router processes the registration in accordance to RFC 3344
[RFC3344]. In addition, the following steps are taken: [RFC3344]. In addition, the following steps are taken:
o Check for Mobile Network Acknowledgement extension(s) in o Check for Mobile Network Acknowledgement extension(s) in
skipping to change at page 9, line 14 skipping to change at page 14, line 7
A Mobile Router can obtain a Collocated or Foreign Agent Care-of A Mobile Router can obtain a Collocated or Foreign Agent Care-of
Address while operating in explicit or implicit modes. Address while operating in explicit or implicit modes.
For de-registration, the Mobile Router sends a registration request For de-registration, the Mobile Router sends a registration request
with lifetime set to zero without any Mobile Network Request with lifetime set to zero without any Mobile Network Request
extensions. extensions.
5.1. Error Processing 5.1. Error Processing
A Mobile Router interprets the values of the Code field in the Mobile In a Mobile IP Registration Reply message there may be two Code
Network Acknowledgement Extension of the Registration Reply in order fields: one proper to the Registration Reply header (the 'proper'
to identify any error related to managing the Mobile Network Prefixes Code) and one within the Mobile Network Acknowledgement Extension
by the Home Agent. (simply the 'Code'). A Mobile Router interprets the values of the
Code field in the Mobile Network Acknowledgement Extension of the
Registration Reply in order to identify any error related to managing
the Mobile Network Prefixes by the Home Agent. It also interprets
the values of the Code field in the Registration Reply header (the
proper Code).
If the value of the Code field in the Registration Reply is set to If the value of the Code field in the Registration Reply (the proper)
HA_MOBNET_DISALLOWED, then the Mobile Router MUST stop sending is set to HA_MOBNET_DISALLOWED, then the Mobile Router MUST stop
Registration Requests with any Mobile Network Prefix extensions to sending Registration Requests with any Mobile Network Prefix
that Home Agent. extensions to that Home Agent.
If the value of the Code field in the Registration Reply is set to If the value of the Code field in the Registration Reply (the proper)
HA_MOBNET_ERROR then the Mobile Router MUST stop sending Registration is set to HA_MOBNET_ERROR then the Mobile Router MUST stop sending
Requests that contain any of the Mobile Network Prefixes that are Registration Requests that contain any of the Mobile Network Prefixes
defined by the values of the fields Prefix and Prefix Length in the that are defined by the values of the fields Prefix and Prefix Length
Mobile Network Acknowledgement extension. Note that the registration in the Mobile Network Acknowledgement extension. Note that the
is denied in this case and no forwarding for any Mobile Network registration is denied in this case and no forwarding for any Mobile
Prefixes would be set up by the Home Agent for the Mobile Router. Network Prefixes would be set up by the Home Agent for the Mobile
Router.
It is possible that the Mobile Router receives a Registration Reply It is possible that the Mobile Router receives a Registration Reply
with no mobile network extensions if the registration was processed with no mobile network extensions if the registration was processed
by a Mobile IPv4 home agent that does not support this specification by a Mobile IPv4 home agent that does not support this specification
at all. In that case, the absence of mobile network extensions must at all. In that case, the absence of mobile network extensions must
be interpreted by the Mobile Router as the case where the Home Agent be interpreted by the Mobile Router as the case where the Home Agent
does not support mobile networks. does not support mobile networks.
All the error code values are TBA (To Be Assigned) subject to IANA All the error code values are TBA (To Be Assigned) subject to IANA
allocation. allocation.
5.2. Mobile Router Management
Operating a Mobile Router in a Mobile IPv4 environment has certain
requirements on the management of the necessary initial configuration
and supervision of the ongoing status information. Mobile Router
maintenance indicators may need to be exposed in a manner consistent
with other Mobile IPv4 indicators.
The objects for the Management Information Base (MIB) for Mobile IPv4
are defined in RFC 2006 [RFC2006]. The structure of the basic model
of Mobile IP protocol describes three entities: Mobile Node, Home
Agent and Foreign Agent. In addition to these entities this document
proposes a functional entity to be the Mobile Router.
The necessary initial configuration at a NEMOv4-enabled Home Agent
includes, but is not limited to, the contents of the Prefix Table.
The Mobile Router MAY need to store the Mobile Network Prefixes as
the initial configuration.
The definition of MIB objects related to Mobile Router and of a
NEMOv4-enabled Home Agent is outside the scope of this document.
6. Home Agent Operation 6. Home Agent Operation
6.1. Summary 6.1. Summary
A Home Agent MUST support all the operations specified in RFC 3344 A Home Agent MUST support all the operations specified in RFC 3344
[RFC3344] and its update [I-D.ietf-mip4-rfc3344bis] for Mobile Node [RFC3344] for Mobile Node support. The Home Agent MUST support both
support. The Home Agent MUST support both implicit and explicit implicit and explicit modes of operation for a Mobile Router.
modes of operation for a Mobile Router.
The Home Agent processes the registration in accordance to RFC 3344 The Home Agent processes the registration in accordance to RFC 3344
[RFC3344], which includes route set up to the Mobile Router's Home [RFC3344], which includes route set up to the Mobile Router's Home
Address via the tunnel to the Care-of Address. In addition, for a Address via the tunnel to the Care-of Address. In addition, for a
Mobile Router registering in explicit mode, the following steps are Mobile Router registering in explicit mode, the following steps are
taken: taken:
1. Check that the Mobile Network Prefix information is valid 1. Check that the Mobile Network Prefix information is valid
2. Ensure the Mobile Network Prefix(es) is or are authorized to be 2. Ensure the Mobile Network Prefix(es) is or are authorized to be
skipping to change at page 10, line 29 skipping to change at page 15, line 48
necessary necessary
6. Send the Registration Reply with the Mobile Network 6. Send the Registration Reply with the Mobile Network
Acknowledgement extension(s) Acknowledgement extension(s)
If there are any subnet routes via the tunnel to the Mobile Router If there are any subnet routes via the tunnel to the Mobile Router
that are not specified in the Mobile Network extensions, these routes that are not specified in the Mobile Network extensions, these routes
are removed. are removed.
In the case where the Mobile Node is not permitted to act as a Mobile In the case where the Mobile Node is not permitted to act as a Mobile
Router, the Home Agent sends a registration denied message with error Router, the Home Agent sends a Registration Reply message whose Code
code HA_MOBNET_DISALLOWED. field is HA_MOBNET_DISALLOWED (the proper Code field of the
Registration Reply).
For a Mobile Router registering in implicit mode, the Home Agent For a Mobile Router registering in implicit mode, the Home Agent
performs steps 3-6 above, once the registration request is processed performs steps 3-6 above, once the registration request is processed
successfully. successfully.
For deregistration, the Home Agent removes the tunnel to the Mobile For deregistration, the Home Agent removes the tunnel to the Mobile
Router and all routes using this tunnel. The Mobile Network Router and all routes using this tunnel. The Mobile Network
extensions are ignored. extensions are ignored.
6.2. Data Structures 6.2. Data Structures
6.2.1. Registration Table 6.2.1. Registration Table
The Registration Table in the Home Agent, in accordance with RFC 3344 The Registration Table in the Home Agent, in accordance with RFC 3344
[RFC3344] and its update [I-D.ietf-mip4-rfc3344bis], contains binding [RFC3344], contains binding information for every Mobile Node
information for every Mobile Node registered with it. RFC 3344 registered with it. RFC 3344 [RFC3344] defines the format of a
[RFC3344] and its update [I-D.ietf-mip4-rfc3344bis] define the format Registration Table. In addition to all the parameters specified by
of a Registration Table. In addition to all the parameters specified RFC 3344 [RFC3344], the Home Agent MUST store the Mobile Network
by RFC 3344 [RFC3344] and its update [I-D.ietf-mip4-rfc3344bis], the Prefixes associated with the Mobile Router in the corresponding
Home Agent MUST store the Mobile Network Prefixes associated with the registration entry, when the corresponding registration was performed
Mobile Router in the corresponding registration entry, when the in explicit mode. When the Home Agent is advertising reachability to
corresponding registration was performed in explicit mode. When the Mobile Network Prefixes served by a Mobile Router, the information
Home Agent is advertising reachability to Mobile Network Prefixes stored in the Registration Table can be used.
served by a Mobile Router, the information stored in the Registration
Table can be used.
6.2.2. Prefix Table 6.2.2. Prefix Table
The Home Agent must be able to authorize a Mobile Router for use of The Home Agent must be able to authorize a Mobile Router for use of
Mobile Network Prefixes when the Mobile Router is operating in Mobile Network Prefixes when the Mobile Router is operating in
explicit mode. Also, when the Mobile Router operates in implicit explicit mode. Also, when the Mobile Router operates in implicit
mode, the Home Agent must be able to locate the Mobile Network mode, the Home Agent must be able to locate the Mobile Network
Prefixes associated with that Mobile Router. The Home Agent may Prefixes associated with that Mobile Router. The Home Agent may
store the Home Address of the Mobile Router along with the mobile store the Home Address of the Mobile Router along with the mobile
network prefixes associated with that Mobile Router. If the Mobile network prefixes associated with that Mobile Router. If the Mobile
Router does not have a Home Address assigned, this table may store Router does not have a Home Address assigned, this table may store
the NAI RFC 2794 [RFC2794] of the Mobile Router that will be used in the NAI RFC 2794 [RFC2794] of the Mobile Router that will be used in
dynamic Home Address assignment. dynamic Home Address assignment.
6.3. Mobile Network Prefix Registration 6.3. Mobile Network Prefix Registration
The Home Agent must process registration requests coming from Mobile The Home Agent must process registration requests coming from Mobile
Routers in accordance with this section. The document RFC 3344 Routers in accordance with this section. The document RFC 3344
[RFC3344] and its update [I-D.ietf-mip4-rfc3344bis] specify that the [RFC3344] specifies that the Home Address of a mobile node
Home Address of a mobile node registering with a Home Agent must registering with a Home Agent must belong to a prefix advertised on
belong to a prefix advertised on the home network. In accordance the home network. In accordance with this specification, however,
with this specification, however, the Home Address must be configured the Home Address must be configured from a prefix that is served by
from a prefix that is served by the Home Agent, not necessarily the the Home Agent, not necessarily the one on the home network.
one on the home network.
If the registration request is valid, the Home Agent checks to see if If the registration request is valid, the Home Agent checks to see if
there are any Mobile Network Prefix extensions included in the there are any Mobile Network Prefix extensions included in the
Registration Request. Registration Request.
If so, the Mobile Network Prefix information is obtained from the If so, the Mobile Network Prefix information is obtained from the
included extensions, and the Home Address from the Home Address field included extensions, and the Home Address from the Home Address field
of the Registration Request. For every Mobile Network Prefix of the Registration Request. For every Mobile Network Prefix
extension included in the registration request, the Home Agent MUST extension included in the registration request, the Home Agent MUST
perform a check against the Prefix Table. If the Prefix Table does perform a check against the Prefix Table. If the Prefix Table does
not contain at least one entry pairing that Home Address to that not contain at least one entry pairing that Home Address to that
Mobile Network Prefix then the check fails, otherwise it succeeds. Mobile Network Prefix then the check fails, otherwise it succeeds.
Following this check against the Prefix Table, the Home Agent MUST Following this check against the Prefix Table, the Home Agent MUST
construct a Registration Reply containing Mobile Network construct a Registration Reply containing Mobile Network
Acknowledgement extensions. For a Mobile Network Prefix for which Acknowledgement extensions. For a Mobile Network Prefix for which
the check was unsuccessfull the Code field in the corresponding the check was unsuccessful the Code field in the corresponding Mobile
Mobile Network Acknowledgement extension should be set to Network Acknowledgement extension should be set to
MOBNET_UNAUTHORIZED. MOBNET_UNAUTHORIZED.
For a Mobile Network Prefix for which the check was successfull the For a Mobile Network Prefix for which the check was successful the
Code field in the respective Mobile Network Acknowledgement Code field in the respective Mobile Network Acknowledgement
extensions should be set to 0. extensions should be set to 0.
The Home Agent MUST attempt to set up forwarding for each Mobile The Home Agent MUST attempt to set up forwarding for each Mobile
Network Prefix extension for which the Prefix Table check was Network Prefix extension for which the Prefix Table check was
successfull. If the forwarding setup fails for a particular Mobile successful. If the forwarding setup fails for a particular Mobile
Network Prefix (for reasons like not enough memory available, or not Network Prefix (for reasons when, for example, there is not enough
enough devices available, or other similar) the Code field in the memory available, or not enough devices available, or other reason)
respective Mobile Network Acknowledgement extension should be set to the Code field in the respective Mobile Network Acknowledgement
MOBNET_FWDING_SETUP_FAILED. extension should be set to MOBNET_FWDING_SETUP_FAILED.
If forwarding and setup was successful for at least one Mobile If forwarding and setup was successful for at least one Mobile
Network Prefix then the Code field of the Registration Reply message Network Prefix then the Code field (proper) of the Registration Reply
should be set to 0. Otherwise that Code should be HA_MOBNET_ERROR. message should be set to 0. Otherwise, when forwarding and setup was
unsuccessful for each and every Mobile Network Prefixes, that Code
(proper) should be HA_MOBNET_ERROR.
If the registration request is sent in implicit mode, i.e., without If the registration request is sent in implicit mode, i.e., without
any Mobile Network Request extension, the Home Agent may use pre- any Mobile Network Request extension, the Home Agent may use pre-
configured mobile network prefix information for the Mobile Router to configured mobile network prefix information for the Mobile Router to
set up forwarding. set up forwarding.
If the Home Agent is updating an existing binding entry for the If the Home Agent is updating an existing binding entry for the
Mobile Router, it MUST check all the prefixes in the registration Mobile Router, it MUST check all the prefixes in the registration
table against the prefixes included in the registration request. If table against the prefixes included in the registration request. If
one or more mobile network prefix is missing from the included one or more mobile network prefix is missing from the included
skipping to change at page 13, line 30 skipping to change at page 18, line 50
able to accept packets tunneled by the Mobile Router with the source able to accept packets tunneled by the Mobile Router with the source
address of the outer header set to the Care-of Address of the Mobile address of the outer header set to the Care-of Address of the Mobile
Router and that of the inner header set to the Mobile Router's Home Router and that of the inner header set to the Mobile Router's Home
Address or an address from one of the registered mobile network Address or an address from one of the registered mobile network
prefixes. prefixes.
6.6. Sending Registration Replies 6.6. Sending Registration Replies
The Home Agent MUST set the status code in the registration reply to The Home Agent MUST set the status code in the registration reply to
0 to indicate successful processing of the registration request and 0 to indicate successful processing of the registration request and
successful set up of forwarding for all the mobile network prefixes successful set up of forwarding for at least one mobile network
served by the Mobile Router. The registration reply MUST contain at prefixes served by the Mobile Router. The registration reply MUST
least one Mobile Network Acknowledgement extension. contain at least one Mobile Network Acknowledgement extension.
If the Home Agent is unable to set up forwarding for one of more If the Home Agent is unable to set up forwarding for one or more
mobile network prefixes served by the Mobile Router, it MUST set the mobile network prefixes served by the Mobile Router, it MUST set the
Mobile Network Acknowledgement Extension status code in the Mobile Network Acknowledgement Extension status Code in the
registration reply to MOBNET_FWDING_SETUP_FAILED. When the prefix registration reply to MOBNET_FWDING_SETUP_FAILED. When the prefix
length is zero or greater than 32, the status code MUST be set to length is zero (and the Optional Netmask field is absent) or greater
than decimal 32, the status Code MUST be set to
MOBNET_INVALID_PREFIX_LEN. MOBNET_INVALID_PREFIX_LEN.
If the Mobile Router is not authorized to forward packets to one or If the Mobile Router is not authorized to forward packets to a mobile
mobile network prefixes included in the request, the Home Agent MUST network prefixes included in the request, the Home Agent MUST set the
set the code to MOBNET_UNAUTHORIZED_MR. Code to MOBNET_UNAUTHORIZED.
6.7. Mobile Network Prefix De-registration 6.7. Mobile Network Prefix De-registration
If the received registration request is for de-registration of the If the received registration request is for de-registration of the
Care-of Address, the Home Agent, upon successful processing of it, Care-of Address, the Home Agent, upon successful processing of it,
MUST delete the entry(ies) from its registration table. The home MUST delete the entry(ies) from its registration table. The home
agent tears down the bi-directional tunnel and stops forwarding any agent tears down the bi-directional tunnel and stops forwarding any
packets to/from the Mobile Router. The Home Agent MUST ignore any packets to/from the Mobile Router. The Home Agent MUST ignore any
included Mobile Network Request extension in a de-registration included Mobile Network Request extension in a de-registration
request. request.
skipping to change at page 15, line 7 skipping to change at page 20, line 25
be arbitrary levels of nested mobility. The operation of each Mobile be arbitrary levels of nested mobility. The operation of each Mobile
Router remains the same whether the Mobile Router attaches to another Router remains the same whether the Mobile Router attaches to another
Mobile Router or to a fixed Access Router on the Internet. The Mobile Router or to a fixed Access Router on the Internet. The
solution described here does not place any restriction on the number solution described here does not place any restriction on the number
of levels for nested mobility. Two issues should be noted though. of levels for nested mobility. Two issues should be noted though.
First, whenever physical loops occur in a nested aggregation of First, whenever physical loops occur in a nested aggregation of
mobile networks this protocol does neither detect nor solve them - mobile networks this protocol does neither detect nor solve them -
datagram forwarding may be blocked. Second, Mobile Routers in a deep datagram forwarding may be blocked. Second, Mobile Routers in a deep
nested aggregation of mobile networks might introduce significant nested aggregation of mobile networks might introduce significant
overhead on the data packets as each level of nesting introduces overhead on the data packets as each level of nesting introduces
another tunnel header encapsulation. another tunnel header encapsulation. Applications that do not
support MTU discovery are adversely affected by the additional header
encapsulations, because the usable MTU is reduced with each level of
nesting.
9. Routing Protocol between Mobile Router and Home Agent 9. Routing Protocol between Mobile Router and Home Agent
There are several benefits of running a dynamic routing protocol There are several benefits of running a dynamic routing protocol
between the Mobile Router and the Home Agent. If the mobile network between the Mobile Router and the Home Agent. If the mobile network
is relatively large, including several wireless subnets, then the is relatively large, including several wireless subnets, then the
topology changes within the moving network can be exposed from the topology changes within the moving network can be exposed from the
Mobile Router to the Home Agent by using a dynamic routing protocol. Mobile Router to the Home Agent by using a dynamic routing protocol.
The purpose of the NEMOv4 protocol extensions to Mobile IPv4, as The purpose of the NEMOv4 protocol extensions to Mobile IPv4, as
defined in previous sections, is not to inform the Home Agent about defined in previous sections, is not to inform the Home Agent about
skipping to change at page 16, line 28 skipping to change at page 21, line 50
The Home Agent MUST be able to verify that the Mobile Router is The Home Agent MUST be able to verify that the Mobile Router is
authorized to provide mobility service for the Mobile Networks in the authorized to provide mobility service for the Mobile Networks in the
registration request, before anchoring these Mobile Network Prefixes registration request, before anchoring these Mobile Network Prefixes
on behalf of the Mobile Router. Forwarding for prefixes MUST NOT be on behalf of the Mobile Router. Forwarding for prefixes MUST NOT be
set up without successful authorization of the Mobile Router for set up without successful authorization of the Mobile Router for
those prefixes. A registration failure MUST be notified to the those prefixes. A registration failure MUST be notified to the
mobile router when it cannot be successfully authorized for prefixes mobile router when it cannot be successfully authorized for prefixes
requested by it. requested by it.
All registration requests and replies MUST be authenticated by the All registration requests and replies MUST be authenticated by the
MN-HA Authentication Extension as specified in RFC 3344 [RFC3344] and MN-HA Authentication Extension as specified in RFC 3344 [RFC3344].
its update [I-D.ietf-mip4-rfc3344bis]. When the registration request
is sent in explicit mode, i.e., with one or more Mobile Network When the registration request is sent in explicit mode, i.e., with
Prefix extensions, all the Mobile Network Prefix extensions MUST be one or more Mobile Network Prefix extensions, all the Mobile Network
included before the MN-HA Authentication extension. Also, these Prefix extensions MUST be included before the MN-HA Authentication
extensions MUST be included in the calculation of the MN-HA extension. Also, these extensions MUST be included in the
authenticator value. calculation of the MN-HA authenticator value.
The Mobile Router should perform ingress filtering on all the packets The Mobile Router should perform ingress filtering on all the packets
received on the mobile network prior to reverse tunneling them to the received on the mobile network prior to reverse tunneling them to the
Home Agent. The Mobile Router MUST drop any packets that do not have Home Agent. The Mobile Router MUST drop any packets that do not have
a source address belonging to the mobile network. a source address belonging to the mobile network.
The Mobile Router MUST also ensure that the source address of packets The Mobile Router MUST also ensure that the source address of packets
arriving on the mobile network is not the same as the Mobile Router's arriving on the mobile network is not the same as the Mobile Router's
IP address on any interface. These checks will protect against nodes IP address on any interface. These checks will protect against nodes
attempting to launch IP spoofing attacks through the bi-directional attempting to launch IP spoofing attacks through the bi-directional
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If a dynamic routing protocol is used between the Mobile Router and If a dynamic routing protocol is used between the Mobile Router and
the Home Agent to propagate the mobile network information into the the Home Agent to propagate the mobile network information into the
home network, the routing updates SHOULD be protected with IPsec ESP home network, the routing updates SHOULD be protected with IPsec ESP
confidentiality between the Mobile Router and Home Agent, to prevent confidentiality between the Mobile Router and Home Agent, to prevent
information about home network topology from being visible to information about home network topology from being visible to
eavesdroppers. eavesdroppers.
11. IANA Considerations 11. IANA Considerations
IANA to modify rules for the existing registry "Mobile IPv4 numbers - IANA to assign rules for the existing registry "Mobile IPv4 numbers -
per RFC 3344". The numbering space for Extensions that may appear in per RFC 3344". The numbering space for Extensions that may appear in
Mobile IP control messages (those sent to and from UDP port number Mobile IP control messages (those sent to and from UDP port number
434) should be modified. 434) should be modified.
The new Values and Names for the Type for Extensions appearing in The new Values and Names for the Type for Extensions appearing in
Mobile IP control messages are the following: Mobile IP control messages are the following:
+-------+---------------------------------------------------+ +-------+---------------------------------------------------+
| Value | Name | | Value | Name |
+-------+---------------------------------------------------+ +-------+---------------------------------------------------+
skipping to change at page 18, line 17 skipping to change at page 23, line 31
+-------+-----------------------------------------+ +-------+-----------------------------------------+
| TBA | Mobile Network Request Extension | | TBA | Mobile Network Request Extension |
| TBA | Explicit Mode Acknowledgement Extension | | TBA | Explicit Mode Acknowledgement Extension |
| TBA | Implicit Mode Acknowledgement Extension | | TBA | Implicit Mode Acknowledgement Extension |
+-------+-----------------------------------------+ +-------+-----------------------------------------+
Table 2: New Values and Names for the Sub-Type for Mobile Network Table 2: New Values and Names for the Sub-Type for Mobile Network
Extensions Extensions
The policy of future assignments to this number space should be The policy of future assignments to this number space should be
following Standards Action or IESG Approval (see following Standards Action or IESG Approval (see [RFC2434]).
[I-D.narten-iana-considerations-rfc2434bis]).
The new Code Values for Mobile IP Registration Reply messages are the The new Code Values for Mobile IP Registration Reply messages are the
following (for a registration denied by the Home Agent): following (for a registration denied by the Home Agent):
+-------+-----------------------------------------------------------+ +-------+-----------------------------------------------------------+
| Value | Name | | Value | Name |
+-------+-----------------------------------------------------------+ +-------+-----------------------------------------------------------+
| TBA | Mobile Network Prefix operation error (HA_MOBNET_ERROR) | | TBA | Mobile Network Prefix operation error (HA_MOBNET_ERROR) |
| TBA | Mobile Router operation is not permitted | | TBA | Mobile Router operation is not permitted |
| | (HA_MOBNET_DISALLOWED) | | | (HA_MOBNET_DISALLOWED) |
skipping to change at page 18, line 49 skipping to change at page 24, line 16
| TBA | Success | | TBA | Success |
| TBA | Invalid prefix length (MOBNET_INVALID_PREFIX_LEN) | | TBA | Invalid prefix length (MOBNET_INVALID_PREFIX_LEN) |
| TBA | Mobile Router is not authorized for prefix | | TBA | Mobile Router is not authorized for prefix |
| | (MOBNET_UNAUTHORIZED) | | | (MOBNET_UNAUTHORIZED) |
| TBA | Forwarding setup failed (MOBNET_FWDING_SETUP_FAILED) | | TBA | Forwarding setup failed (MOBNET_FWDING_SETUP_FAILED) |
+-----+-------------------------------------------------------------+ +-----+-------------------------------------------------------------+
Table 4: New Code Values for Mobile Network Acknowledgement Extension Table 4: New Code Values for Mobile Network Acknowledgement Extension
The policy of future assignments to this number space should be The policy of future assignments to this number space should be
following Standards Action or IESG Approval (see following Standards Action or IESG Approval (see [RFC2434]).
[I-D.narten-iana-considerations-rfc2434bis]).
The current non-modified numbering spaces could be consulted at the The current non-modified numbering spaces could be consulted at the
URL http://www.iana.org/assignments/mobileip-numbers (contents last URL http://www.iana.org/assignments/mobileip-numbers (contents last
updated 2007-12-20 and last browsed 2008-01-04). updated 2007-12-20 and last browsed 2008-01-04).
12. Acknowledgements 12. Acknowledgements
The authors would like to thank Christophe Janneteau, George The authors would like to thank Christophe Janneteau, George
Popovich, Ty Bekiares, Ganesh Srinivasan, Alpesh Patel, Ryuji Popovich, Ty Bekiares, Ganesh Srinivasan, Alpesh Patel, Ryuji
Wakikawa, George Tsirtsis, and Henrik Levkowetz for their helpful Wakikawa, George Tsirtsis, and Henrik Levkowetz for their helpful
discussions, reviews and comments. Vijay Devarapalli extensively discussions, reviews and comments. Vijay Devarapalli extensively
reviewed one of the later versions of the draft. Hans Sjostrand reviewed one of the later versions of the draft. Hans Sjostrand
(Hans Sj\"ostrand) identified the last clarifications with respect to (Hans Sj\"ostrand) identified the last clarifications with respect to
Foreign Agent mode treatment. Pete McCann contributed necessary Foreign Agent mode treatment. Pete McCann contributed necessary
refinements of many statements. refinements of many statements.
Mobile IPv4 versions as early as 1996 (RFC 2002) described Mobile Mobile IPv4 versions as early as 1996 (RFC 2002) described Mobile
Networks and Mobile Routers support. Charles Perkins. Networks and Mobile Routers support. Charles Perkins.
Fred Templin indicated the potential confusion for the term "LFN".
Amanda Baber of IANA agreed on the principles of allocating numbers
for this specification and suggested improvements on the IANA
section.
Tim Polk of IESG identified a deeply entrenched error on managing the
Code fields.
Lars Eggert of IESG suggested the acommodation of the otherwise legal
non-contiguous netmask fields, instead of simply prefix lengths.
Dan Romascanu of IESG indicated the necessity of manageability of
Mobile Routers and NEMOv4-enabled Home Agents and their deployability
in MIP4 environments.
David Borman of TSV-DIR reviewed this document as part of the
transport area directorate's ongoing effort to review key IETF
documents. The implications of the growth of usable MTU adversely
affecting applications deep in a mobile network were suggested.
Gonzalo Camarillo provided a generalist review by an additional set
of eyes for documents as they are being considered for publication
(General Area Review Team).
Jari Arkko of IESG reviewed, suggested necessary improvements to, and
diligently shepherded this document through IESG.
13. References 13. References
13.1. Normative References 13.1. Normative References
[RFC1323] Jacobson, V., Braden, B., and D. Borman, "TCP Extensions
for High Performance", RFC 1323, May 1992.
[RFC2006] Cong, D., Hamlen, M., and C. Perkins, "The Definitions of
Managed Objects for IP Mobility Support using SMIv2",
RFC 2006, October 1996.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997. Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2328] Moy, J., "OSPF Version 2", STD 54, RFC 2328, April 1998. [RFC2328] Moy, J., "OSPF Version 2", STD 54, RFC 2328, April 1998.
[RFC2434] Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", BCP 26, RFC 2434,
October 1998.
[RFC2453] Malkin, G., "RIP Version 2", STD 56, RFC 2453, [RFC2453] Malkin, G., "RIP Version 2", STD 56, RFC 2453,
November 1998. November 1998.
[RFC2794] Calhoun, P. and C. Perkins, "Mobile IP Network Access [RFC2794] Calhoun, P. and C. Perkins, "Mobile IP Network Access
Identifier Extension for IPv4", RFC 2794, March 2000. Identifier Extension for IPv4", RFC 2794, March 2000.
[RFC3344] Perkins, C., "IP Mobility Support for IPv4", RFC 3344, [RFC3344] Perkins, C., "IP Mobility Support for IPv4", RFC 3344,
August 2002. August 2002.
[RFC4271] Rekhter, Y., Li, T., and S. Hares, "A Border Gateway [RFC4271] Rekhter, Y., Li, T., and S. Hares, "A Border Gateway
Protocol 4 (BGP-4)", RFC 4271, January 2006. Protocol 4 (BGP-4)", RFC 4271, January 2006.
[RFC4885] Ernst, T. and H-Y. Lach, "Network Mobility Support
Terminology", RFC 4885, July 2007.
13.2. Informative References 13.2. Informative References
[I-D.ietf-mip4-nemov4-fa] [I-D.ietf-mip4-nemov4-fa]
Tsirtsis, G., Park, V., Narayanan, V., and K. Leung, "FA Tsirtsis, G., Park, V., Narayanan, V., and K. Leung, "FA
extensions to NEMOv4 Base", draft-ietf-mip4-nemov4-fa-01 extensions to NEMOv4 Base", draft-ietf-mip4-nemov4-fa-01
(work in progress), November 2007. (work in progress), November 2007.
[I-D.ietf-mip4-rfc3344bis]
Perkins, C., "IP Mobility Support for IPv4, revised",
draft-ietf-mip4-rfc3344bis-05 (work in progress),
July 2007.
[I-D.narten-iana-considerations-rfc2434bis]
Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs",
draft-narten-iana-considerations-rfc2434bis-08 (work in
progress), October 2007.
[RFC3963] Devarapalli, V., Wakikawa, R., Petrescu, A., and P. [RFC3963] Devarapalli, V., Wakikawa, R., Petrescu, A., and P.
Thubert, "Network Mobility (NEMO) Basic Support Protocol", Thubert, "Network Mobility (NEMO) Basic Support Protocol",
RFC 3963, January 2005. RFC 3963, January 2005.
Appendix A. ChangeLog Appendix A. ChangeLog
[RFC Editor: please remove this section prior to publication. (said
IESG member Russ Housley on 6th of February 2008: "Please delete
Appendix A before publication as an RFC.")]
The changes are listed in reverse chronological order, most recent The changes are listed in reverse chronological order, most recent
changes appearing at the top of the list. changes appearing at the top of the list.
From draft-ietf-mip4-nemo-v4-base-08.txt to
draft-ietf-mip4-nemo-v4-base-09.txt, following IANA and IESG
comments:
o Introduced an Optional Netmask field in both registrations and
replies. This is used when address/prefixlength is not a
sufficient expression of network mask, for example when the subnet
mask needs to be expressed as a non-contiguous set of 1bits (e.g.
255.255.0.255). Also described the reasoning of this in a section
of its own.
o Extended the Introduction section with two subsections: example of
mobile network and overall protocol operation. Illustrated two
figures.
o Added Local Fixed Node term definition and some citations to
reference rfc4885 "Network Mobility Support Terminology".
o Clarified text about the Code field. There are two Code fields:
one in Registration Reply header (the Code proper) and one in the
Mobile Network Extension header. Also clarified conditions of
proper Code being 0 successful and and relationships of proper
Code 0 to Code in the Mobile Network Extension.
o Added a sub-section 'Mobile Router Management' about the initial
configuration, ongoing supervision and management indicators of a
Mobile Router and Home Agent.
o Substituted 'MOBNET_UNAUTHORIZED' for 'MOBNET_UNAUTHORIZED_MR'.
o Substituted 'IANA to assign rules' for 'IANA to modify rules'.
o Stressed that "applications that do not support MTU discovery are
adversely affected by the additional header encapsulations,
because the usable MTU is reduced with each level of nesting."
o Removed citations and reference to rfc3344bis
(draft-ietf-mip4-rfc3344bis-05).
o Removed citations and reference to rfc2434bis
(draft-narten-iana-considerations-rfc2434bis-08).
o Extended the Acknowledgements section.
From draft-ietf-mip4-nemo-v4-base-07.txt to From draft-ietf-mip4-nemo-v4-base-07.txt to
draft-ietf-mip4-nemo-v4-base-08.txt, following AD Review (Jari draft-ietf-mip4-nemo-v4-base-08.txt, following AD Review (Jari
Arkko): Arkko):
o HA propagates Mobile Network Prefix only if necessary (previously o HA propagates Mobile Network Prefix only if necessary (previously
it was always doing it). it was always doing it).
o emphasized that within nested mobile networks looping may occur o emphasized that within nested mobile networks looping may occur
and this document doesn't do anything to address this. and this document doesn't do anything to address this.
skipping to change at page 22, line 5 skipping to change at page 28, line 51
non-optimized double-encapsulation operation is supported and non-optimized double-encapsulation operation is supported and
[I-D.ietf-mip4-nemov4-fa] proposes a optimization. [I-D.ietf-mip4-nemov4-fa] proposes a optimization.
From draft-ietf-mip4-nemo-v4-base-02.txt to From draft-ietf-mip4-nemo-v4-base-02.txt to
draft-ietf-mip4-nemo-v4-base-03.txt draft-ietf-mip4-nemo-v4-base-03.txt
o changed a sentence in the Introduction to say that FA mode _is_ o changed a sentence in the Introduction to say that FA mode _is_
supported but unoptimized, and that a reference supported but unoptimized, and that a reference
[I-D.ietf-mip4-nemov4-fa] optimizes that mode. [I-D.ietf-mip4-nemov4-fa] optimizes that mode.
o added reference [I-D.ietf-mip4-rfc3344bis] to the rfc3344bis o added I-D.ietf-mip4-rfc3344bis reference to the rfc3344bis draft.
draft.
From draft-ietf-mip4-nemo-v4-base-01.txt to From draft-ietf-mip4-nemo-v4-base-01.txt to
draft-ietf-mip4-nemo-v4-base-02.txt draft-ietf-mip4-nemo-v4-base-02.txt
o changed title from "IPv4 Network Mobility (NEMO) Protocol" to o changed title from "IPv4 Network Mobility (NEMO) Protocol" to
"Network Mobility (NEMO) Extensions for Mobile IPv4". "Network Mobility (NEMO) Extensions for Mobile IPv4".
From draft-ietf-mip4-nemo-v4-base-00.txt to From draft-ietf-mip4-nemo-v4-base-00.txt to
draft-ietf-mip4-nemo-v4-base-01.txt draft-ietf-mip4-nemo-v4-base-01.txt
 End of changes. 60 change blocks. 
195 lines changed or deleted 512 lines changed or added

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