IPv6 Operations Working Group A. Matsumoto
Internet-Draft T. Fujisaki
Intended status: Informational NTT
Expires: May 9, 2008 R. Hiromi
K. Kanayama
Intec Netcore
November 6, 2007
Requirements for address selection mechanisms
draft-ietf-v6ops-addr-select-req-04.txt
Status of this Memo
By submitting this Internet-Draft, each author represents that any
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
aware will be disclosed, in accordance with Section 6 of BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that
other groups may also distribute working documents as Internet-
Drafts.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt.
The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html.
This Internet-Draft will expire on May 9, 2008.
Copyright Notice
Copyright (C) The IETF Trust (2007).
Abstract
In a multi-prefix environment, nodes could have multiple addresses on
one network interface. RFC 3484 defines a source and destination
address-selection algorithm, which is commonly deployed in current
popular OSs. However, nodes could encounter some difficulties in
network communication when they use default address selection rules
Matsumoto, et al. Expires May 9, 2008 [Page 1]
Internet-Draft Address-Selection Req November 2007
defined in RFC 3484. Some mechanisms for solving address-selection
problems are proposed including the RFC 3484 policy table
distribution and ICMP error-based mechanisms. This document
describes requirements for these address-selection mechanisms.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Requirements of Address Selection . . . . . . . . . . . . . . . 3
2.1. Effectiveness . . . . . . . . . . . . . . . . . . . . . . . 3
2.2. Timing . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.3. Dynamic Behavior Update . . . . . . . . . . . . . . . . . . 4
2.4. Node-Specific Behavior . . . . . . . . . . . . . . . . . . 4
2.5. Application-Specific Behavior . . . . . . . . . . . . . . . 4
2.6. Multiple Interface . . . . . . . . . . . . . . . . . . . . 4
2.7. Central Control . . . . . . . . . . . . . . . . . . . . . . 4
2.8. Next-hop Selection . . . . . . . . . . . . . . . . . . . . 4
2.9. Compatibility with RFC 3493 . . . . . . . . . . . . . . . . 4
3. Security Considerations . . . . . . . . . . . . . . . . . . . . 5
3.1. List of threats introduced by new address-selection
mechanism . . . . . . . . . . . . . . . . . . . . . . . . . 5
3.2. List of recommendations in which security mechanism
should be applied . . . . . . . . . . . . . . . . . . . . . 5
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 6
5. References . . . . . . . . . . . . . . . . . . . . . . . . . . 6
5.1. Normative References . . . . . . . . . . . . . . . . . . . 6
5.2. Informative References . . . . . . . . . . . . . . . . . . 6
Appendix A. Appendix. Revision History . . . . . . . . . . . . . . 6
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 7
Intellectual Property and Copyright Statements . . . . . . . . . . 9
Matsumoto, et al. Expires May 9, 2008 [Page 2]
Internet-Draft Address-Selection Req November 2007
1. Introduction
One physical network can have multiple logical networks. In that
case, an end-host has multiple IP addresses. (e.g., in the IPv4-IPv6
dual-stack environment, in a site that uses both ULA [RFC4193] and
global scope addresses or in a site connected to multiple upstream
IPv6 networks) For such a host, RFC 3484 [RFC3484] defines default
address-selection rules for the source and destination addresses.
Today, the RFC 3484 mechanism is widely implemented in major OSs.
However, we and others have found that in many sites the default
address-selection rules are not appropriate for the network
structure. PS [I-D.ietf-v6ops-addr-select-ps] lists problematic
cases that resulted from incorrect address selection.
Though RFC 3484 made the address-selection behavior of a host
configurable, typical users cannot make use of that because of the
complexity of the mechanism and lack of knowledge about their network
topologies. Therefore, an address-selection autoconfiguration
mechanism is necessary, especially for unmanaged hosts of typical
users.
This document contains requirements for address-selection mechanisms
that enable hosts to perform appropriate address selection
automatically.
2. Requirements of Address Selection
Address-selection mechanisms have to fulfill the following seven
requirements.
2.1. Effectiveness
The mechanism can modify RFC 3484 default address-selection behavior
at nodes. As documented in PS [I-D.ietf-v6ops-addr-select-ps], the
default rules defined in RFC 3484 do not work properly in some
environments. Therefore, the mechanism has to be able to modify
address-selection behavior of a host.
2.2. Timing
Nodes can obtain address selection information when necessary. If
nodes need to have address-selection information before performing
address selection, then the mechanism has to provide a function for
nodes to obtain necessary information beforehand. The mechanism
should not degrade usability. The mechanism should not enforce long
address-selection processing time upon users.
Matsumoto, et al. Expires May 9, 2008 [Page 3]
Internet-Draft Address-Selection Req November 2007
2.3. Dynamic Behavior Update
Address-selection behavior of nodes can be dynamically updated. When
the network structure changes and address-selection behavior has to
be changed accordingly, a network administrator can modify the
address-selection behavior of nodes.
2.4. Node-Specific Behavior
The mechanism can support node-specific address-selection behavior.
Even when multiple nodes are on the same subnet, the mechanism should
be able to provide a method for the network administrator to make
nodes behave differently. For example, each node may have a
different set of assigned prefixes. In such a case, the appropriate
address-selection behavior may be different.
2.5. Application-Specific Behavior
The mechanism can support application-specific address-selection
behavior or combined use with an application-specific address-
selection mechanism such as address-selection APIs.
2.6. Multiple Interface
The mechanism can support those nodes equipped with multiple
interfaces. The mechanism has to assume that nodes have multiple
interfaces and makes address selection of those nodes work
appropriately.
2.7. Central Control
The address selection behavior of nodes can be centrally controlled.
A site administrator or a service provider could determine or could
have effect on address-selection behavior at their users' hosts.
2.8. Next-hop Selection
The mechanism can control next-hop-selection behavior at hosts or
cooperate with other routing mechanisms, such as routing protocols
and RFC 4191 [RFC4191]. If the address-selection mechanism is used
with a routing mechanism, the two mechanisms have to be able to work
synchronously.
2.9. Compatibility with RFC 3493
The mechanism can allow an application that uses the basic socket
interface defined in RFC 3493 [RFC3493] to work correctly. That is,
with the basic socket interface the application can select an
Matsumoto, et al. Expires May 9, 2008 [Page 4]
Internet-Draft Address-Selection Req November 2007
appropriate source and destination addresses and can communicate with
the destination host. This requirement does not necessarily mean
that OS protocol stack and socket libraries should not be changed.
3. Security Considerations
3.1. List of threats introduced by new address-selection mechanism
There are some security incidents when combining these requirements
described in Section 2 into a protocol. In particular, here are six
possible threats.
1. Hijacking or tapping from malicious nodes connecting from beyond
unapproved network boundaries.
2. Malicious changing of policy data by nonapproved nodes.
3. Denial of Service Attack due to higher traffic volume, and
blocked communication, for example, at both node and network
caused by sending unsafe and tampered data from unbidden
controller.
4. Attempt to stop service on node/computer resources caused by
unnecessary communication between the controller and nodes.
5. Intrusion into security boundary caused by malicious use of
multiprefix environment.
6. Leakage of network policy information from central controller.
3.2. List of recommendations in which security mechanism should be
applied
All the methods listed below should be well-considered for protecting
against security threats. There is no necessity to comply with all
items at same time, if one or more spec(s) could apply to other
security requirements. Secure network operation will also be
considered, and describing network operation for network security
will be better. Referring to and using existing technologies is also
preferable.
1. Consideration of the necessity to use digitally signed or
cryptographic messages.
2. Consideration of the necessity to maintain confidentiality of
source of policy data.
3. Consideration of the necessity of authentication and validation
of both entity and message integrity.
4. Consideration of the necessity of having a mechanism for the
avoidance of data conflicts if the policy data comes from
multiple controllers.
Matsumoto, et al. Expires May 9, 2008 [Page 5]
Internet-Draft Address-Selection Req November 2007
5. Consideration of the necessity of an appropriate filtering method
at domain boundaries.
6. Consideration of the necessity of data independency at every node
or every interface for avoidance of mixing multiple policy data.
7. Consideration of the necessity of having a mechanism for
controlling policy and all related network information on the
server if the server stores policy and all related neetowrk
information on the outside of its network domain.
8. Consideration of the necessity to log and collect related system
data.
4. IANA Considerations
This document has no actions for IANA.
5. References
5.1. Normative References
[I-D.ietf-v6ops-addr-select-ps]
Matsumoto, A., "Problem Statement of Default Address
Selection in Multi-prefix Environment: Operational Issues
of RFC3484 Default Rules",
draft-ietf-v6ops-addr-select-ps-02 (work in progress),
October 2007.
[RFC3484] Draves, R., "Default Address Selection for Internet
Protocol version 6 (IPv6)", RFC 3484, February 2003.
[RFC3493] Gilligan, R., Thomson, S., Bound, J., McCann, J., and W.
Stevens, "Basic Socket Interface Extensions for IPv6",
RFC 3493, February 2003.
5.2. Informative References
[RFC4191] Draves, R. and D. Thaler, "Default Router Preferences and
More-Specific Routes", RFC 4191, November 2005.
[RFC4193] Hinden, R. and B. Haberman, "Unique Local IPv6 Unicast
Addresses", RFC 4193, October 2005.
Appendix A. Appendix. Revision History
04:
Matsumoto, et al. Expires May 9, 2008 [Page 6]
Internet-Draft Address-Selection Req November 2007
A new requirement item "Compatibility with RFC 3493" was added,
which reflected a comment from Remi Denis-Courmont at the v6ops
mailing list.
03:
Security Consideration section was rewritten according to comments
from SECDIR.
02:
The description and evaluation of solution approaches were
separated into a new document called
draft-arifumi-v6ops-addr-select-sol-00.
01:
Other than policy table distribution approach, the solution
section included several solutions discussed at 67th IETF meeting.
Authors' Addresses
Arifumi Matsumoto
NTT PF Lab
Midori-Cho 3-9-11
Musashino-shi, Tokyo 180-8585
Japan
Phone: +81 422 59 3334
Email: arifumi@nttv6.net
Tomohiro Fujisaki
NTT PF Lab
Midori-Cho 3-9-11
Musashino-shi, Tokyo 180-8585
Japan
Phone: +81 422 59 7351
Email: fujisaki@nttv6.net
Ruri Hiromi
Intec Netcore, Inc.
Shinsuna 1-3-3
Koto-ku, Tokyo 136-0075
Japan
Phone: +81 3 5665 5069
Email: hiromi@inetcore.com
Matsumoto, et al. Expires May 9, 2008 [Page 7]
Internet-Draft Address-Selection Req November 2007
Ken-ichi Kanayama
Intec Netcore, Inc.
Shinsuna 1-3-3
Koto-ku, Tokyo 136-0075
Japan
Phone: +81 3 5665 5069
Email: kanayama@inetcore.com
Matsumoto, et al. Expires May 9, 2008 [Page 8]
Internet-Draft Address-Selection Req November 2007
Full Copyright Statement
Copyright (C) The IETF Trust (2007).
This document is subject to the rights, licenses and restrictions
contained in BCP 78, and except as set forth therein, the authors
retain all their rights.
This document and the information contained herein are provided on an
"AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND
THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF
THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
Intellectual Property
The IETF takes no position regarding the validity or scope of any
Intellectual Property Rights or other rights that might be claimed to
pertain to the implementation or use of the technology described in
this document or the extent to which any license under such rights
might or might not be available; nor does it represent that it has
made any independent effort to identify any such rights. Information
on the procedures with respect to rights in RFC documents can be
found in BCP 78 and BCP 79.
Copies of IPR disclosures made to the IETF Secretariat and any
assurances of licenses to be made available, or the result of an
attempt made to obtain a general license or permission for the use of
such proprietary rights by implementers or users of this
specification can be obtained from the IETF on-line IPR repository at
http://www.ietf.org/ipr.
The IETF invites any interested party to bring to its attention any
copyrights, patents or patent applications, or other proprietary
rights that may cover technology that may be required to implement
this standard. Please address the information to the IETF at
ietf-ipr@ietf.org.
Acknowledgment
Funding for the RFC Editor function is provided by the IETF
Administrative Support Activity (IASA).
Matsumoto, et al. Expires May 9, 2008 [Page 9]
