Internet Draft RJ Atkinson
draft-irtf-rrg-ilnp-v4opts-04.txt Consultant
Expires: 29 NOV 2012 SN Bhatti
Category: Experimental U. St Andrews
29 May 2012
IPv4 Options for ILNPv4
draft-irtf-rrg-ilnp-v4opts-04.txt
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Internet-Drafts are working documents of the Internet Engineering
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Internet-Drafts are draft documents valid for a maximum of six
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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/1id-abstracts.html
The list of Internet-Draft Shadow Directories can be accessed at
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This document is not on the IETF standards-track and does not
specify any level of standard. This document merely provides
information for the Internet community.
This document is part of the ILNP document set, and has had
extensive review within the IRTF Routing Research Group. ILNP is
one of the recommendations made by the RG Chairs. Separately,
various refereed research papers on ILNP have also been published
during this decade. So the ideas contained herein have had much
broader review than the IRTF Routing RG. The views in this
document were considered controversial by the Routing RG, but the
RG reached a consensus that the document still should be
published. The Routing RG has had remarkably little consensus on
anything, so virtually all Routing RG outputs are considered
controversial.
Abstract
This document defines 2 new IPv4 options that are used only with
ILNP for IPv4 (ILNPv4). ILNP is is an experimental, evolutionary
enhancement to IP. This document is a product of the IRTF Routing
RG.
Table of Contents - ### to be updated
1. Introduction.............................2
2. IPv4 Options for ILNPv4..................3
3. Security Considerations..................7
4. IANA Considerations......................7
5. References...............................8
1. INTRODUCTION
The Identifier Locator Network Protocol (ILNP) is an proposal for
evolving the Internet Architecture. It differs from the current
Internet Architecture primarily by deprecating the concept of an
IP Address, and instead defining two new objects, each having
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crisp syntax and semantics. The first new object is the Locator,
a topology-dependent name for a subnetwork. The other new object
is the Identifier, which provides a topology-independent name for
a node.
1.1 ILNP Document Roadmap
The ILNP Architecture document [ILNP-ARCH] is the best place to
start reading about ILNP. ILNP has multiple instantiations.
[ILNP-ENG] discusses engineering and implementation aspects
common to all instances of ILNP. This document discusses
engineering and implementation details that are specific to ILNP
for IPv4 (ILNPv4). [ILNP-DNS] describes new Domain Name System
(DNS) resource records used with ILNP. [ILNP-ICMPv4] defines the
ICMP Locator Update message used with ILNPv4. Other documents
describe ILNP for IPv6 (ILNPv6) [ILNP-ICMPv6] [ILNP-NONCE6].
1.2 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. [RFC2119]
2. IPv4 Options for ILNPv4
ILNP for IPv4 (ILNPv4) is merely a different instantiation of the
ILNP architecture, so it retains the crisp distinction between
the Locator and the Identifier. As with ILNP for IPv6 (ILNPv6),
when ILNPv4 is used for a network-layer session, the upper-layer
protocols (e.g. TCP/UDP pseudo-header checksum, IPsec Security
Association) bind only to the Identifiers, never to the Locators.
As with ILNPv6, only the Locator values are used for routing and
forwarding ILNPv4 packets.
However, just as the packet format for IPv4 is different to IPv6,
so the engineering details for ILNPv4 are different also. Just as
ILNPv6 is carefully engineered to be backwards-compatible with
IPv6, ILNPv4 is carefully engineered to be backwards-compatible
with IPv4.
Each of these options MUST be copied upon fragmentation. Each of
these options is used for control, so uses Option Class 0.
Originally, these two options were specified to use separate IP
option numbers. However, only 1 IP option (decimal 158) has been
defined for experimental use with properties of MUST COPY and
CONTROL.[RFC4727] So these two options have been re-worked to share
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that same IP option number (158). To distinguish between
the two actual options, the unsigned 8-bit field ILNPv4_OPT
inside this option is examined.
It is important for implementers to understand that IP Option 158
is not uniquely allocated to ILNPv4. Other IPv4-related
experiments might be using that IP option value for different IP
options having different IP option formats.
2.1 ILNPv4 Packet Format
The Source IP Address in the IPv4 header becomes the Source
ILNPv4 Locator value, while the Destination IP Address of the
IPv4 header becomes the Destination ILNPv4 Locator value. Of
course, backwards compatibility requirements mean that ILNPv4
Locators use the same number space as IPv4 routing prefixes.
ILNPv4 uses the same 64-bit Identifier, with the same modified
EUI-64 syntax, as ILNPv6. Because the IPv4 address fields are
much smaller than the IPv6 address fields, ILNPv4 cannot carry
the Identifier values in the fixed portion of the IPv4 header.
The obvious two ways to carry the ILNP Identifier with ILNPv4
are either as an IPv4 Option or as an IPv6-style Extension Header
placed after the IPv4 header and before the upper-layer protocol
(e.g. OSPF, TCP, UDP, SCTP).
Currently deployed IPv4 routers from multiple router vendors use
packet forwarding silicon that is able to parse past IPv4 options
to examine the upper-layer protocol header at wire-speed on
reasonably fast (e.g. 1 Gbps or better) network interfaces. By
contrast, no existing IPv4-capable packet forwarding silicon is
able to parse past a new Extension Header for IPv4. Hence, for
engineering reasons, ILNPv4 uses a new IPv4 Option to carry the
Identifier values. Another new IPv4 option also carries a nonce
value, performing the same function for ILNPv4 as the IPv6 Nonce
Destination Option [ILNP-NONCE6] performs for ILNPv6.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Version| IHL |Type of Service| Total Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Identification |Flags| Fragment Offset |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Time to Live | Protocol | Header Checksum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Source Locator (32 bits) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| Destination Locator (32 bits) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OT=158 | OL=5 | 0x00 |ILNPv4_OPT=0x01|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ Source Identifier +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ Destination Identifier +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OT=158 | OL=2 | 0x00 |ILNPv4_OPT=0x02|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| top 32 bits of nonce |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| lower 32 bits of nonce |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1: ILNPv4 header with ILNP ID option
and ILNP Nonce option.
Notation for Figure 1:
IHL: Internet Header Length
OT: Option Type
OL: Option Length
2.2 ILNP Identifier Option for IPv4
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OT=158 | OL=20 | 0x00 |ILNPv4_OPT=0x01|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Source Identifier |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Destination Identifier |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2: ILNP Identifier Option for IPv4
Notation for Figure 2:
OT: Option Type
OL: Option Length
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RFC-791, Page 15 specifies that the Option Length is measured in
words and includes the Option Type octet, the Option Length
octet, and the option data octets.
The Source Identifier and Destination Identifier are unsigned
64-bit integers. [ILNP-ENG] specifies the syntax, semantics, and
generation of ILNP Identifier values. Using the same syntax and
semantics for all instantiations of ILNP Identifiers simplifies
specification and implementation, while also facilitating
translation or transition between ILNPv4 and ILNPv6 should that
be desirable in future.
This IP option MUST NOT be present in an IPv4 packet unless
the packet is part of an ILNPv4 session. ILNPv4 sessions
MUST include this option in the first few packets of each
session, and MAY include this option in all packets of the
session. It is RECOMMENDED to include this option in all
packets of the session if packet loss higher than normal.
2.3 ILNP Nonce Option for IPv4
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OT=158 | OL=2 | 0x00 |ILNPv4_OPT=0x02|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| top 32 bits of nonce |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| lower 32 bits of nonce |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3: ILNP Nonce Option for IPv4
Notation for Figure 3:
OT: Option Type
OL: Option Length
This option contains a 64-bit ILNP Nonce. As noted in [ILNP-
ARCH] and [ILNP-ENG], all ILNP Nonce values are unidirectional.
This means, for example, that a typical TCP/ILNPv4 session will
have two different NONCE values: one from Initiator to Responder
and another from Responder to Initiator. The ILNP Nonce is used
to provide non-cryptographic protection against off-path attacks
(e.g. forged ICMP messages from the remote end of a TCP session).
Each NONCE value MUST be unpredictable (i.e. cryptographically
random). Guidance to implementers on generating
cryptographically random values is provided in [RFC4086].
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This IP option MUST NOT be present in an IPv4 packet unless the
packet is part of an ILNPv4 session. ILNPv4 nodes MUST include
this option in the first few packets of each ILNP session, MUST
include this option in all ICMP messages generated by endpoints
participating in an ILNP session, and MAY include this option in
all packets of an ILNPv4 session.
3. SECURITY CONSIDERATIONS
Security considerations for the overall ILNP Architecture are
described in [ILNP-ARCH]. Additional common security
considerations are described in [ILNP-ENG]. This section
describes security considerations specific to ILNPv4 topics
discussed in this document.
If the ILNP Nonce value is predictable, then an off-path attacker
might be able to forge data or control packets. This risk also
is mitigated by the existing common practice of IP Source Address
filtering [RFC2827] [RFC3704].
IP Security for ILNP [ILNP-ENG] [RFC4301] provides cryptographic
protection for ILNP data and control packets. The ILNP Nonce
option is required in the circumstances described in Section 3,
even if IP Security is also in use. Deployments of ILNPv4 in
high-threat environments SHOULD use IP Security for additional
risk reduction.
This option is intended to be used primarily end-to-end between a
source node and a destination node. However, unlike IPv6, IPv4
does not specify a method to distinguish between options with
hop-by-hop behaviour versus end-to-end behaviour.
[ID-IPv4-OPT-FILTERING] provides general discussion of potential
operational issues with IPv4 options, along with specific advice
for handling several specific IPv4 options. Further, many
deployed modern IP routers (both IPv4 and IPv6) have been
explicitly configured to ignore all IP options, even including
the "Router Alert" option, when forwarding packets not addressed
to the router itself. Reports indicate this has been done to
preclude use of IP options as a (Distributed) Denial-of-Service
(D)DoS attack vector on backbone routers.
4. IANA CONSIDERATIONS
This document makes no request of IANA.
If in future the IETF decided to standardise ILNPv4, then
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allocation of two unique Header Option values to ILNPv4, one for
the Identifier option and one for the Nonce option, would be
sensible.
5. REFERENCES
This document has both Normative and Informational References.
5.1 Normative References
[ILNP-ARCH] R.J. Atkinson & S.N. Bhatti, "ILNP Architecture",
draft-irtf-rrg-ilnp-arch, May 2012.
[ILNP-ENG] R.J. Atkinson & S.N. Bhatti, "ILNP Engineering
Considerations", draft-irtf-rrg-ilnp-eng, May 2012.
[ILNP-DNS] R.J. Atkinson & S.N. Bhatti, "DNS Resource Records
for ILNP", draft-irtf-rrg-ilnp-dns, May 2012.
[ILNP-ICMPv4] R.J. Atkinson & S.N. Bhatti, "ICMP Locator Update
message for ILNPv4", draft-irtf-rrg-ilnp-icmpv4,
May 2012.
[RFC2119] Bradner, S., "Key words for use in RFCs to
Indicate Requirement Levels", BCP 14, RFC 2119,
March 1997.
[RFC4301] S. Kent and K. Seo, "Security Architecture for
the Internet Protocol", RFC-4301, December 2005.
[RFC4727] B. Fenner, "Experimental Values in IPv4, IPv6, ICMPv4,
ICMPv6, UDP, and TCP Headers", RFC 4727, Nov 2006.
5.2 Informative References
[ID-IPv4-OPT-FILTERING] F. Gont, R. Atkinson, and C. Pignatero,
"Recommendations on Filtering of IPv4 Packets with
IPv4 options", draft-gont-opsec-ip-options-filtering,
March 2012.
[ILNP-NONCE6] R.J. Atkinson & S.N. Bhatti, "ILNPv6 Nonce
Destination Option", draft-irtf-rrg-ilnp-noncev6,
May 2012.
[ILNP-ICMPv6] R.J. Atkinson & S.N. Bhatti, "ICMPv6 Locator
Update Message for ILNPv6",
draft-irtf-rrg-ilnp-icmpv6, May 2012.
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[RFC2780] S. Bradner & V. Paxson, "IANA Allocation Guidelines
for Values in the Internet Protocol and Related
Headers", RFC 2780, March 2000.
[RFC2827] P. Ferguson and D. Senie, "Network Ingress
Filtering: Defeating Denial of Service Attacks
which employ IP Source Address Spoofing",
RFC-2827, May 2000.
[RFC3704] F. Baker and P. Savola, "Ingress Filtering for
Multihomed Networks", RFC-3704, March 2004.
[RFC4086] D. Eastlake 3rd, J. Schiller, and S. Crocker,
"Randomness Requirements for Security", RFC-4086,
June 2005.
ACKNOWLEDGEMENTS
Steve Blake, Stephane Bortzmeyer, Mohamed Boucadair, Noel
Chiappa, Wes George, Steve Hailes, Joel Halpern, Mark Handley,
Volker Hilt, Paul Jakma, Dae-Young Kim, Tony Li, Yakov Rehkter,
Bruce Simpson, Robin Whittle and John Wroclawski (in alphabetical
order) provided review and feedback on earlier versions of this
document. Steve Blake provided an especially thorough review of
an early version of the entire ILNP document set, which was
extremely helpful. We also wish to thank the anonymous reviewers
of the various ILNP papers for their feedback.
Roy Arends provided expert guidance on technical and procedural
aspects of DNS issues.
RFC EDITOR NOTE
This section is to be removed prior to publication.
Please note that this document is written in British English, so
British English spelling is used throughout. This is consistent
with existing practice in several other RFCs, for example
RFC-5887.
This document tries to be very careful with history, in the
interest of correctly crediting ideas to their earliest
identifiable author(s). So in several places the first published
RFC about a topic is cited rather than the most recent published
RFC about that topic.
AUTHOR'S ADDRESS
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RJ Atkinson
Consultant
San Jose, CA,
95125 USA
Email: rja.lists@gmail.com
SN Bhatti
School of Computer Science
University of St Andrews
North Haugh, St Andrews
Fife, Scotland
KY16 9SX, UK
Email: saleem@cs.st-andrews.ac.uk
Expires: 29 NOV 2012
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