Internet DRAFT - draft-ietf-nemo-v4-base
draft-ietf-nemo-v4-base
Network Working Group K. Leung
Internet-Draft G. Dommety
Expires: December 26, 2006 Cisco Systems
V. Narayanan
QUALCOMM, Inc.
A. Petrescu
Motorola
June 26, 2006
IPv4 Network Mobility (NEMO) Basic Support Protocol
draft-ietf-nemo-v4-base-01.txt
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Copyright Notice
Copyright (C) The Internet Society (2006).
Abstract
This document describes the support of Mobile Networks, as defined in
Mobile IPv4, by the Mobile Router and Home Agent. A Mobile Router is
responsible for the mobility of one or more network segments or
subnets moving together. The Mobile Router hides its mobility from
the nodes on the mobile network. The nodes on the Mobile Network may
be fixed in relationship to the Mobile Router and may not have any
mobility function.
Extensions to Mobile IPv4 are introduced to support Mobile Networks.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Requirements . . . . . . . . . . . . . . . . . . . . . . . . . 3
4. Mobile Network Extensions . . . . . . . . . . . . . . . . . . 4
4.1. Mobile Network Request Extension . . . . . . . . . . . . . 4
4.2. Mobile Network Acknowledgement Extension . . . . . . . . . 5
5. Mobile Router Operation . . . . . . . . . . . . . . . . . . . 6
5.1. Error Processing . . . . . . . . . . . . . . . . . . . . . 7
6. Home Agent Operation . . . . . . . . . . . . . . . . . . . . . 7
6.1. Summary . . . . . . . . . . . . . . . . . . . . . . . . . 7
6.2. Data Structures . . . . . . . . . . . . . . . . . . . . . 8
6.2.1. Registration Table . . . . . . . . . . . . . . . . . . 8
6.2.2. Prefix Table . . . . . . . . . . . . . . . . . . . . . 8
6.3. Mobile Network Prefix Registration . . . . . . . . . . . . 9
6.4. Advertising Mobile Network Reachability . . . . . . . . .10
6.5. Establishment of Bi-directional Tunnel . . . . . . . . . .10
6.6. Sending Registration Replies . . . . . . . . . . . . . . .10
6.7. Mobile Network Prefix De-registration . . . . . . . . . .11
7. Data Forwarding Operation . . . . . . . . . . . . . . . . . .11
8. Nested Mobile Networks . . . . . . . . . . . . . . . . . . . .11
9. Security Considerations . . . . . . . . . . . . . . . . . . .12
10. IANA Considerations . . . . . . . . . . . . . . . . . . . . .13
11. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . .14
12. References . . . . . . . . . . . . . . . . . . . . . . . . . .14
12.1. Normative References . . . . . . . . . . . . . . . . . . .14
12.2. Informative References . . . . . . . . . . . . . . . . . .14
13. Changelog . . . . . . . . . . . . . . . . . . . . . . . . . .14
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . .15
Intellectual Property and Copyright Statements . . . . . . . . . .16
1. Introduction
This document describes protocol extensions to Mobile IPv4
([RFC3344]) to enable support for Mobile Networks. A Mobile Network
is defined as a network segment or subnet that can change its point
of attachment to the routing infrastructure. Such 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 devices on the Mobile Network.
Mobility for the Mobile Network is supported by the Mobile Router
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 or
explicitly identified by the Mobile Router) are advertised by the
Home Agent for route propagation. Traffic to and from nodes in the
Mobile Network are tunneled by the Home Agent to the Mobile Router,
and vice versa. Though packets from the Mobile Network can be
forwarded directly without tunneling when reverse tunneling is not
enabled, reachability is still subject to ingress filtering
conditions for the path in this case.
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This document specifies an additional tunnel between 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
can be eliminated because the Mobile Router is the recipient of the
encapsulated packets for the Mobile Network.
All traffic between the nodes in the Mobile Network and Correspondent
Nodes passes through the Home Agent. This document does not cover
route optimization of this traffic.
A similar protocol has been documented in [RFC3963] for supporting
IPv6 moving networks with Mobile IPv6 extensions.
Multihoming for Mobile Routers is outside of scope of this document.
2. Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119].
Terminology for network mobility support is defined in [RFC3344]. In
addition, this document defines the following terms.
Mobile Network Prefix
The network prefix of the subnet delegated to a Mobile Router
as the Mobile Network.
Prefix Table
A list of Mobile Network Prefixes indexed by the Home Address
of a Mobile Router. The Home Agent manages and uses Prefix
Table to determine which Mobile Network Prefixes belong to a
particular Mobile Router.
3. Requirements
Although Mobile IPv4 stated that Mobile Network can be supported by
the Mobile Router and Home Agent using static configuration or
running a routing protocol, there is no solution for explicit
registration of the Mobile Networks served by the Mobile Router. The
following requirements for Mobile Network support are enumerated:
o A Mobile Router should be able to operate in explicit or implicit
mode. A Mobile Router may explicitly inform the Home Agent which
Mobile Network(s) need to be propagated via routing protocol. A
Mobile Router may also function in implicit mode, where the Home
Agent may learn the mobile networks through other means, such as
from the AAA server or via pre-configuration.
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o The Mobile Network should be supported using Foreign Agents that
are compliant to RFC 3344 without any changes.
o The mobile network should allow Fixed nodes, Mobile Nodes, or
Mobile Routers to be on it.
4. Mobile Network Extensions
4.1. Mobile Network Request Extension
For Explicit Mode, the Mobile Router informs the Home Agent about the
Mobile Network Prefixes during registration. The Registration
Request contains zero, one or several Mobile Network Request
extensions in addition to any other extensions defined by or in the
context of ([RFC3344]). When several Mobile Networks are needed to
be registered, each is included in a separate Mobile Network Request
extension, with its own Type, Length, Sub-Type, Prefix Length and
Prefix fields. A Mobile Network Request extension is encoded in
Type-Length-Value (TLV) format and respects the following format:
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 | Sub-Type | Prefix Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Prefix |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type:
Mobile Network Extension (skippable type range to be assigned
by IANA)
Length:
6
Sub-Type:
1 (Mobile Network Request)
Prefix Length:
8-bit unsigned integer indicating the number of bits covering
the network part of the address contained in the Prefix field.
Prefix:
32-bit unsigned integer in network byte-order containing an
IPv4 address whose first Prefix Length bits make up the Mobile
Network Prefix.
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4.2. Mobile Network Acknowledgement Extension
The Registration Reply contains zero, one or several Mobile Network
Acknowledgement extensions in addition to any other extensions
defined by or in the context of ([RFC3344]). For Implicit Mode,
the Mobile Network Acknowledgement informs the Mobile Router the
prefixes served by the Home Agent. Policies such as permitting
only traffic from these Mobile Networks to be tunneled to the Home
Agent may be applied by the Mobile Router. For Explicit Mode, when
several Mobile Networks are needed to be acknowledged explicitly,
each is included in a separate Mobile Network Acknowledgement
extension, with its own Type, Sub-Type, Length and Prefix Length
fields. Optionally, all requested Mobile Networks could be
acknowledged using only one Mobile Network Acknowledgement
extension with "Prefix Length" and "Prefix" fields set to zero. At
least one Mobile Network Acknowledgement extension MUST be in a
successful Registration Reply to indicate to the Mobile 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 and Implicit Mode Acknowledgements
sub-types. Both sub-types can be present in a single Registration
Reply. A Mobile Network Acknowledgement extension is encoded in
Type-Length-Value (TLV) format and respects the following format:
When the registration is denied with code HA_MOBNET_ERROR, the Code
field in the extension provides the reason for the failure.
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 | Sub-Type | Code |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Prefix Length | Reserved | Prefix
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type:
Mobile Network Extension (skippable type range to be assigned
by IANA)
Length:
8
Sub-Type:
TBA (Explicit Mode Acknowledgement)
TBA (Implicit Mode Acknowledgement)
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Code:
Value indicating success or failure.
0 Success
TBA Invalid prefix (MOBNET_INVALID_PREFIX_LEN)
TBA MR is not authorized for prefix (MOBNET_UNAUTHORIZED)
TBA Forwarding setup failed (MOBNET_FWDING_SETUP_FAILED)
Prefix Length:
8-bit unsigned integer indicating the number of bits covering
the network part of the address contained in the Prefix field.
Reserved:
Sent as zero; ignored on reception.
Prefix:
32-bit unsigned integer in network byte-order containing an
IPv4 address whose first Prefix Length bits make up the Mobile
Network Prefix.
5. Mobile Router Operation
A Mobile Router's operation is generally derived from the behavior of
a Mobile Node, as set in ([RFC3344]). In addition to maintaining
mobility bindings for its Home Address, the Mobile Router, together
with the Home Agent, maintains forwarding information for the Mobile
Network Prefix(es) assigned to the Mobile Router.
A Mobile Router SHOULD set the 'T' bit to 1 in all Registration
Request messages it sends to indicate the need for reverse tunnels
for all traffic. Without reverse tunnels, all the traffic from the
mobile network will be subject to ingress filtering in the visited
networks. Upon reception of successful registration reply, the
Mobile Router processes the registration in accordance to RFC 3344.
In addition, the following steps are taken:
o Check for Mobile Network Acknowledgement extension(s) in
Registration Reply
o Create tunnel to the Home Agent if registered in reverse tunneling
mode
o Set up default route via this tunnel or egress interface when
registered with or without reverse tunneling, respectively
In accordance with this specification, a Mobile Router may operate in
one of the following two modes: explicit and implicit. In explicit
mode, the Mobile Router includes Mobile Network Prefix information in
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all Registration Requests (as Mobile Network Request extensions),
while in implicit mode it does not include this information in any
Registration Request. In this latter case, the Home Agent obtains
the Mobile Network Prefixes by other means than Mobile IP.
A Mobile Router can obtain a Collocated or Foreign Agent Care-of-
Address while operating in explicit or implicit modes.
For de-registration, the Mobile Router sends a registration request
with lifetime set to zero without any Mobile Network Request
extensions.
5.1. Error Processing
A Mobile Router interprets the values of the Code field in 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.
If the value of the Code field in the Registration Reply is set to
HA_MOBNET_DISALLOWED, then the Mobile Router MUST stop sending
Registration Requests with any Mobile Network Prefix extensions to
that Home Agent.
If the value of the Code field in the Registration Reply is set to
HA_MOBNET_ERROR then the Mobile Router MUST stop sending Registration
Requests that contain any of the Mobile Network Prefixes that are
defined by the values of the fields Prefix and Prefix Length in the
Mobile Network Acknowledgement extension. Note that the registration
is denied in this case and no forwarding for any Mobile 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
with no mobile network extensions if the registration was processed
by a Mobile IPv4 home agent that does not support this specification
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
does not support mobile networks.
All the error code values are TBA (To Be Assigned) subject to IANA
allocation.
6. Home Agent Operation
6.1. Summary
A Home Agent MUST support all the operations specified in ([RFC3344])
for mobile node support. The Home Agent MUST support both implicit
and explicit modes of operation for a Mobile Router.
The Home Agent processes the registration in accordance to RFC 3344,
which includes route set up to the Mobile Router's home address via
the tunnel to the Care-of Address. In addition, for a Mobile Router
registering in explicit mode, the following steps are taken:
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1. Check that the subnet information is valid
2. Ensure such subnet is authorized to be on the Mobile Router
3. Create tunnel to the Mobile Router if it does not already exist
4. Set up route for the subnets via this tunnel
5. Propagate subnet routes via routing protocol
6. Send the Registration Reply with the Mobile Network
Acknowledgement extension(s)
If there are any subnet routes via the tunnel to the Mobile Router
that are not specified in the Mobile Network extensions, these routes
are removed.
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
code HA_MOBNET_DISALLOWED.
For a Mobile Router registering in implicit mode, the Home Agent
performs steps 3-6 above, once the registration request is processed
successfully.
For deregistration, the Home Agent removes the tunnel to the Mobile
Router and all routes using this tunnel. The Mobile Network
extensions are ignored.
6.2. Data Structures
6.2.1. Registration Table
The registration table in the Home Agent, in accordance with
([RFC3344]), contains binding information for every mobile node
registered with it. In addition to all the parameters specified by
([RFC3344]), the home agent MUST store the mobile network prefixes
associated with the Mobile Router in the corresponding registration
entry, when the corresponding registration was performed in explicit
mode. When the Home Agent is advertising reachability to mobile
network prefixes served by a Mobile Router, this information stored
in the registration table can be used.
6.2.2. Prefix Table
The Home Agent must be able to authorize a Mobile Router for use of
mobile network prefixes when the Mobile Router is operating in
explicit mode. Also, when the Mobile Router operates in implicit
mode, the Home Agent must be able to locate the mobile network
prefixes associated with that Mobile Router. The Home Agent may
store the home address of the Mobile Router along with the mobile
network prefixes associated with that Mobile Router. If the Mobile
Router does not have a home address assigned, this table may store
the NAI ([RFC2794]) of the Mobile Router that will be used in dynamic
home address assignment.
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6.3. Mobile Network Prefix Registration
The Home Agent must process registration requests coming from Mobile
Routers in accordance with this section. ([RFC3344]) specifies that
the home address of a mobile node registering with a Home Agent must
belong to a prefix advertised on the home network. In accordance
with this specification, however, the home address must be configured
from a prefix that is served by the Home Agent, not necessarily the
one on the home network.
If the registration request is valid, the Home Agent checks to see
if there are any Mobile Network Prefix extensions included in the
Registration Request. If so, the Mobile Network Prefix information
is obtained from the included extensions, and the Home Address from
the Home Address field of the UDP header Registration Request. For
every Mobile Network Prefix extension included in the registration
request, the Home Agent MUST perform a check against the Prefix
Table. If the Prefix Table does not contain at least one entry
pairing that Home Address to that Mobile Network Prefix then the
check fails, otherwise it succeeds.
Following this check against the Prefix Table, the Home Agent MUST
construct a Registration Reply containing Mobile Network
Acknowledgement extensions. For a Mobile Network Prefix for which
the check was unsuccessfull the Code field in the corresponding
Mobile Network Acknowledgement extension should be set to
MOBNET_UNAUTHORIZED. For a Mobile Network Prefix for which the
check was successfull the Code field in the respective Mobile
Network Acknowledgement extensions should be set to 0.
The Home Agent MUST attempt to set up forwarding for each Mobile
Network Prefix extension for which the Prefix Table check was
successfull. If the forwarding setup fails for a particular Mobile
Network Prefix (for reasons like not enough memory available, or
not enough devices available, or other similar) the Code field in
the respective Mobile Network Acknowledgement extension should be
set to MOBNET_FWDING_SETUP_FAILED.
If forwarding and setup was successful for at least one Mobile
Network Prefix then the Code field of the Registration Reply
message should be set to 0. Otherwise that Code should be
HA_MOBNET_ERROR.
If the registration request is sent in implicit mode, i.e., without
any Mobile Network Request extension, the Home Agent may use pre-
configured mobile network prefix information for the Mobile Router to
set up forwarding.
If the Home Agent is updating an existing binding entry for the
Mobile Router, it MUST check all the prefixes in the registration
table against the prefixes included in the registration request.
If one or more mobile network prefix is missing from the included
information in the registration request, it MUST delete those
prefixes from the registration table. Also, the Home Agent MUST
disable forwarding for those prefixes.
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If all checks are successful, the Home Agent either creates a new
entry(ies) for the Mobile Router or updates an existing binding
entry(ies) for it and returns a successful registration reply back
to the Mobile Router or the Foreign Agent (if the registration
request was received from a Foreign Agent).
In accordance with ([RFC3344]), the Home Agent does proxy ARP for
the Mobile Router home address, when the Mobile Router home address
is derived from the home network. If the 'T' bit is set, the Home
Agent creates a bi-directional tunnel for the corresponding mobile
network prefixes or updates the existing bi-directional tunnel.
This tunnel is maintained independent of the reverse tunnel for the
Mobile Router home address itself.
6.4. Advertising Mobile Network Reachability
If the mobile network prefixes served by the Home Agent are
aggregated with the home network prefix and if the Home Agent is the
default router on the home network, the Home Agent does not have to
do anything different than normal. The routes for the mobile network
prefix are automatically aggregated into the home network prefix. If
the Mobile Router updates the mobile network prefix routes via a
dynamic routing protocol, the Home Agent SHOULD propagate the routes
on the appropriate networks.
6.5. Establishment of Bi-directional Tunnel
The Home Agent creates and maintains a bi-directional tunnel for the
mobile network prefixes of a Mobile Router registered with it. A
home agent supporting IPv4 Mobile Router operation MUST be able to
forward packets destined to the mobile network prefixes served by the
mobile router to its care-of-address. Also, the Home Agent MUST be
able to accept packets tunneled by the Mobile Router with the source
address of the outer header is set to the care-of-address of the
mobile router and that of the inner header is set to the Mobile
Router's home address or an address from one of the registered mobile
network prefixes.
6.6. Sending Registration Replies
The Home Agents MUST set the status code in the registration reply to
0 to indicate successful processing of the registration request and
successful set up of forwarding for all the mobile network prefixes
served by the Mobile Router. The registration reply MUST contain at
least one Mobile Network Acknowledgement extension.
If the Home Agent is unable to set up forwarding for one of more
mobile network prefixes served by the Mobile Router, it MUST set the
Mobile Network Acknowledgement Extension status code in the
registration reply to MOBNET_FWDING_SETUP_FAILED. When the prefix
length is zero or greater than 32, the status code MUST be set to
MOBNET_INVALID_PREFIX_LEN.
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If the Mobile Router is not authorized to forward packets to one or
mobile network prefixes included in the request, the Home Agent MUST
set the code to MOBNET_UNAUTHORIZED_MR.
6.7. Mobile Network Prefix De-registration
If the received registration request is for de-registration of the
care-of-address, the Home Agent, upon successful processing of it,
MUST delete the entry(ies) from its registration table. The home
agent tears down the bi-directional tunnel and stops forwarding any
packets to/from the Mobile Router. The Home Agent MUST ignore any
included Mobile Network Request extension in a de-registration
request.
7. Data Forwarding Operation
For traffic to the nodes in the Mobile Network, the Home Agent MUST
perform double tunneling of the packet, if the Mobile Router had
registered with a Foreign Agent care-of-address. In this case, the
Home Agent MUST encapsulate the packet with tunnel header (source IP
address set to Home Agent and destination IP address set to Mobile
Router's home address) and then encapsulate one more time with tunnel
header (source IP address set to Home Agent and destination IP
address set to CoA).
For optimization, the Home Agent SHOULD only encapsulate the packet
with the tunnel header (source IP address set to Home Agent and
destination IP address set to CoA) for Collocated CoA mode.
When a Home Agent receives a packet from the mobile network prefix in
the bi-directional tunnel, it MUST de-encapsulate the packet and
route it as a normal IP packet. It MUST verify that the incoming
packet has the source IP address set to the care-of-address of the
Mobile Router. The packet MUST be dropped if the source address is
not set to the care-of-address of the Mobile Router.
For traffic from the nodes in the Mobile Network, the Mobile Router
encapsulates the packet with tunnel header (source IP address set to
Mobile Router's home address and destination IP address set to Home
Agent) if reverse tunnel is enabled. Otherwise, the packet is routed
directly to the Foreign Agent or access router.
In Collocated CoA mode, the Mobile Router MAY encapsulate one more
time with tunnel header (source IP address set to the CoA and
destination IP address set to Home Agent). For optimization, the
Mobile Router SHOULD encapsulate the packet only with the tunnel
header (source IP address set to CoA and destination IP address set
to the Home Agent).
8. Nested Mobile Networks
Nested Network Mobility is a scenario where a Mobile Router allows
another Mobile Router to attach to its Mobile Network. There could
be arbitrary levels of nested mobility. The operation of each Mobile
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Router remains the same whether the Mobile Router attaches to another
Mobile Router or to a fixed Access Router on the Internet. The
solution described here does not place any restriction on the number
of levels for nested mobility. But note that this might introduce
significant overhead on the data packets as each level of nesting
introduces another tunnel header encapsulation.
9. Security Considerations
The Mobile Network extension is protected by the same rules for
Mobile IP extensions in registration messages. See the Security
Considerations section in RFC 3344.
The Home Agent MUST be able to verify that the Mobile Router is
authorized to provide mobility service for the Mobile Networks in the
registration request, before anchoring these subnets on behalf of the
Mobile Router. Forwarding for prefixes MUST NOT be set up without
successful authorization of the Mobile Router for those prefixes. A
registration failure MUST be notified to the mobile router when it
cannot be successfully authorized for prefixes requested by it.
All registration requests and replies MUST be authenticated by the
MN-HA Authentication Extension as specified in ([RFC3344]). When the
registration request is sent in explicit mode, i.e., with one or more
Mobile Network Prefix extensions, all the Mobile Network Prefix
extensions MUST be included before the MN-HA Authentication
extension. Also, these extensions MUST be included in the
calculation of the MN-HA authenticator value.
The Mobile Router should perform ingress filtering on all the packets
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
a source address belonging to the mobile network. 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 IP address on
any interface. These checks will protect against nodes attempting to
launch IP spoofing attacks through the bi-directional tunnel.
The Home Agent, upon receiving packets through the bi-directional
tunnel, MUST verify that the source addresses of the outer IP header
of the packets are set to the Mobile Router's care-of-address. Also,
it MUST ensure that the source address of the inner IP header is a
topologically correct address on the mobile network. This will
prevent nodes from using the Home Agent to launch attacks inside the
protected network.
If a dynamic routing protocol is used between the Mobile Router and
the Home Agent to propagate the mobile network information into the
home network, the routing updates SHOULD be protected with IPsec ESP
confidentiality between the Mobile Router and Home Agent, to prevent
information about home network topology from being visible to
eavesdroppers.
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10. IANA Considerations
IANA to modify rules for the existing registry "Mobile IPv4 numbers -
per RFC 3344". The numbering space for Extensions that may appear in
Mobile IP control messages (those sent to and from UDP port number
434) should be modified.
The new Values and Names for the Type for Extensions appearing in
Mobile IP control messages are the following:
Value Name
----- ------------------------------------------
TBA Mobile Network Extension (To Be Assigned by IANA)
The new Values and Names for the Sub-Type for Mobile Network
Extension are the following:
Value Name
----- ------------------------------------------
TBA Mobile Network Request Extension
TBA Explicit Mode Acknowledgement Extension
TBA Implicit Mode Acknowledgement Extension
The new Code values for Mobile IP Registration Reply messages are the
following:
Code Values for Mobile IP Registration Reply messages
-----------------------------------------------------
Registration denied by the Home Agent: (To Be Assigned by IANA)
TBA Mobile Network Prefix operation error (HA_MOBNET_ERROR)
TBA MR operation is not permitted (HA_MOBNET_DISALLOWED)
The new Code Values for Mobile IP Registration Reply messages are the
following:
Code Values for Mobile Network Acknowledgement Extension
--------------------------------------------------------
Registration denied by the Home Agent:
TBA Invalid prefix length (MOBNET_INVALID_PREFIX_LEN)
TBA MR is not authorized for prefix (MOBNET_UNAUTHORIZED)
TBA Forwarding setup failed (MOBNET_FWDING_SETUP_FAILED)
The current (non-modified) numbering spaces could be consulted at the
following URL: http://www.iana.org/assignments/mobileip-numbers
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11. Acknowledgements
The authors would like to thank Christophe Janneteau, George
Popovich, Ty Bekiares, Ganesh Srinivasan, Alpesh Patel, Ryuji
Wakikawa, George Tsirtsis and Henrik Levkowetz for their helpful
discussions, reviews and comments.
12. References
12.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2794] Calhoun, P. and C. Perkins, "Mobile IP Network Access
Identifier Extension for IPv4", RFC 2794, March 2000.
[RFC3344] Perkins, C., "IP Mobility Support for IPv4", RFC 3344,
August 2002.
12.2. Informative References
[RFC3963] Devarapalli, V., Wakikawa, R., Petrescu, A., and P.
Thubert, "Network Mobility (NEMO) Basic Support Protocol",
RFC 3963, January 2005.
13. Changelog
From version 00 to 01:
-removed error code HA_MOBNET_UNSUPPORTED.
-changed all values to be assigned by IANA, from specific
numbers to "TBA" (To Be Assigned).
-substituted "egress interface" for "roaming interface".
-changed HA behaviour upon reception of MNPs. In 00 the HA
replied positively only if all MNPs in RegReq were valid, in 01
a reply is constructed specifying which MNP was valid and which
not.
-clarified a 3-line paragraph saying that RegRep may contain
both implicit and explicit acknowledgements.
Leung, et al. Expires December 26, 2006 [Page 14]
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Authors' Addresses
Kent Leung
Cisco Systems
170 W. Tasman Drive
San Jose, CA 95134
US
Phone: +1 408-526-5030
Email: kleung@cisco.com
Gopal Dommety
Cisco Systems
170 W. Tasman Drive
San Jose, CA 95134
US
Phone: +1 408-525-1404
Email: gdommety@cisco.com
Vidya Narayanan
QUALCOMM, Inc.
5775 Morehouse Dr
San Diego, CA
USA
Phone: +1 858-845-2483
Email: vidyan@qualcomm.com
Alexandru Petrescu
Motorola
Parc les Algorithmes Saint Aubin
Gif-sur-Yvette 91193
France
Email: Alexandru.Petrescu@motorola.com
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Leung, et al. Expires December 26, 2006 [Page 16]
