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IPv4 Options for ILNPv4

The information below is for an old version of the document.
Document Type
This is an older version of an Internet-Draft that was ultimately published as RFC 6746.
Authors Ran Atkinson , SN Bhatti
Last updated 2012-05-24 (Latest revision 2012-05-17)
RFC stream Internet Research Task Force (IRTF)
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IESG IESG state Became RFC 6746 (Experimental)
Telechat date (None)
Needs a YES.
Responsible AD Ralph Droms
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Send notices to,,,
Internet Draft                                           RJ Atkinson
draft-irtf-rrg-ilnp-v4opts-03.txt                         Consultant
Expires:  17 NOV 2012                                      SN Bhatti
Category: Experimental                                 U. St Andrews
                                                         17 May 2012

                        IPv4 Options for ILNPv4

Status of this Memo

   Distribution of this memo is unlimited.

   Copyright (c) 2012 IETF Trust and the persons identified as the
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   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   This document may contain material from IETF Documents or
   IETF Contributions published or made publicly available
   before November 10, 2008. The person(s) controlling the copyright
   in some of this material may not have granted the IETF Trust the
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   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF), its areas, and its working groups. Note that
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   Internet-Drafts are draft documents valid for a maximum of six
   months and may be updated, replaced, or obsoleted by other

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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

   The list of current Internet-Drafts can be accessed at

   The list of Internet-Draft Shadow Directories can be accessed at

   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


   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

Table of Contents - ### to be updated

     1. Introduction.............................
     2. IPv4 Options for ILNPv4..................
     3. Security Considerations..................
     4. IANA Considerations......................
     5. References...............................


   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
   "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.

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.

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   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.

    |Version|  IHL  |Type of Service|          Total Length         |
    |         Identification        |Flags|      Fragment Offset    |
    |  Time to Live |    Protocol   |         Header Checksum       |
    |                 Source Locator (32 bits)                      |
    |              Destination Locator (32 bits)                    |
    | OT=ILNPv4_ID  |     OL=5      |      Padding=0x0000           |
    |                                                               |
    +                      Source Identifier                        +
    |                                                               |
    |                                                               |
    +                    Destination Identifier                     +
    |                                                               |
    |OT=ILNPv4_NONCE|     OL=2      |      top 16 bits of nonce     |
    |                     lower 32 bits of nonce                    |

           Figure 1:  ILNPv4 header with ILNP ID option

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                                  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

    | OT=ILNPv4_ID  |     OL=20     |      Reserved (16 bits)       |
    |                      Source Identifier                        |
    |                                                               |
    |                    Destination Identifier                     |
    |                                                               |

           Figure 2: ILNP Identifier Option for IPv4

           Notation for Figure 2:
                    OT:   Option Type
                    OL:   Option Length

   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 Reserved field is
   reserved for possible future use.  For now, senders MUST
   initialise this field to all zero values, and receivers MUST
   ignore the contents of this field.

   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.

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2.3  ILNP Nonce Option for IPv4

    |OT=ILNPv4_NONCE|     OL=8      |      NONCE (upper 16 bits)    |
    |                      NONCE (lower 32 bits)                    |

           Figure 3: ILNP Nonce Option for IPv4

           Notation for Figure 3:
                    OT:   Option Type
                    OL:   Option Length

   This option contains a 48-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].

   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.


   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

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   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.


   Subject to IESG Approval, consistent with the procedures of
   [RFC2780], IANA is requested to assign new IPv4 option values for
   the ILNPv4 Identifier option (ILNPv4_ID) and the ILNPv4 Nonce
   option (ILNPv4_NONCE).

   The short name for ILNPv4_ID is "NID", for consistency with
   [ILNP-DNS], and the short name for ILNPv4_NONCE is "INONCE".

   Each of these options MUST be copied upon fragmentation.
   Each of these options is used for control, so uses Option Class 0.


   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.

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   [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.

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.

   [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.


   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,

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   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.


   This section is to be removed prior to publication.

   This document is written in English, not American.  So English
   spelling is used throughout, rather than American spelling.
   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.


   RJ Atkinson
   San Jose, CA,
   95125 USA


   SN Bhatti
   School of Computer Science
   University of St Andrews
   North Haugh, St Andrews
   Fife, Scotland
   KY16 9SX, UK


   Expires: 17 NOV 2012

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