GENWiki

Premier IT Outsourcing and Support Services within the UK

User Tools

Site Tools

Problem, Formatting or Query -  Send Feedback

Was this page helpful?-10+1


rfc:rfc6743

Internet Research Task Force (IRTF) RJ Atkinson Request for Comments: 6743 Consultant Category: Experimental SN Bhatti ISSN: 2070-1721 U. St Andrews

                                                         November 2012
                  ICMP Locator Update Message for
     the Identifier-Locator Network Protocol for IPv6 (ILNPv6)

Abstract

 This note specifies an experimental ICMPv6 message type used with the
 Identifier-Locator Network Protocol (ILNP).  The Identifier-Locator
 Network Protocol (ILNP) is an experimental, evolutionary enhancement
 to IP.  This message is used to dynamically update Identifier/Locator
 bindings for an existing ILNP session.  This is a product of the IRTF
 Routing Research Group.

Status of This Memo

 This document is not an Internet Standards Track specification; it is
 published for examination, experimental implementation, and
 evaluation.
 This document defines an Experimental Protocol for the Internet
 community.  This document is a product of the Internet Research Task
 Force (IRTF).  The IRTF publishes the results of Internet-related
 research and development activities.  These results might not be
 suitable for deployment.  This RFC represents the individual
 opinion(s) of one or more members of the Routing Research Group of
 the Internet Research Task Force (IRTF).  Documents approved for
 publication by the IRSG are not a candidate for any level of Internet
 Standard; see Section 2 of RFC 5741.
 Information about the current status of this document, any errata,
 and how to provide feedback on it may be obtained at
 http://www.rfc-editor.org/info/rfc6743.

Atkinson & Bhatti Experimental [Page 1] RFC 6743 ILNPv6 ICMP November 2012

Copyright Notice

 Copyright (c) 2012 IETF Trust and the persons identified as the
 document authors.  All rights reserved.
 This document is subject to BCP 78 and the IETF Trust's Legal
 Provisions Relating to IETF Documents
 (http://trustee.ietf.org/license-info) in effect on the date of
 publication of this document.  Please review these documents
 carefully, as they describe your rights and restrictions with respect
 to this document.
 This document may not be modified, and derivative works of it may not
 be created, except to format it for publication as an RFC or to
 translate it into languages other than English.

Table of Contents

 1. Introduction ....................................................3
    1.1. Document Roadmap ...........................................3
    1.2. ICMPv6 Locator Update ......................................4
    1.3. Terminology ................................................5
 2. Syntax ..........................................................5
    2.1. Example ICMPv6 Locator Update Message ......................7
 3. Transport Protocol Effects ......................................8
 4. Implementation Considerations ...................................8
 5. Backwards Compatibility .........................................8
 6. Security Considerations .........................................9
 7. IANA Considerations .............................................9
 8. References .....................................................10
    8.1. Normative References ......................................10
    8.2. Informative References ....................................10
 9. Acknowledgements ...............................................11

Atkinson & Bhatti Experimental [Page 2] RFC 6743 ILNPv6 ICMP November 2012

1. Introduction

 This document is part of the ILNP document set, which has had
 extensive review within the IRTF Routing RG.  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.
 At present, the Internet research and development community are
 exploring various approaches to evolving the Internet Architecture to
 solve a variety of issues including, but not limited to, scalability
 of inter-domain routing [RFC4984].  A wide range of other issues
 (e.g., site multihoming, node multihoming, site/subnet mobility, node
 mobility) are also active concerns at present.  Several different
 classes of evolution are being considered by the Internet research
 and development community.  One class is often called "Map and
 Encapsulate", where traffic would be mapped and then tunnelled
 through the inter-domain core of the Internet.  Another class being
 considered is sometimes known as "Identifier/Locator Split".  This
 document relates to a proposal that is in the latter class of
 evolutionary approaches.

1.1. Document Roadmap

 This document defines a new ICMPv6 Locator Update message used by an
 ILNP node to inform its correspondent nodes of any changes to its set
 of valid Locators.
 The ILNP architecture can have more than one engineering
 instantiation.  For example, one can imagine a "clean-slate"
 engineering design based on the ILNP architecture.  In separate
 documents, we describe two specific engineering instances of ILNP.
 The term "ILNPv6" refers precisely to an instance of ILNP that is
 based upon, and backwards compatible with, IPv6.  The term "ILNPv4"
 refers precisely to an instance of ILNP that is based upon, and
 backwards compatible with, IPv4.
 Many engineering aspects common to both ILNPv4 and ILNPv6 are
 described in [RFC6741].  A full engineering specification for either
 ILNPv6 or ILNPv4 is beyond the scope of this document.
 Readers are referred to other related ILNP documents for details not
 described here:

Atkinson & Bhatti Experimental [Page 3] RFC 6743 ILNPv6 ICMP November 2012

 a) [RFC6740] is the main architectural description of ILNP, including
    the concept of operations.
 b) [RFC6741] describes engineering and implementation considerations
    that are common to both ILNPv4 and ILNPv6.
 c) [RFC6742] defines additional DNS resource records that support
    ILNP.
 d) [RFC6744] defines a new IPv6 Nonce Destination Option used by
    ILNPv6 nodes (1) to indicate to ILNP correspondent nodes (by
    inclusion within the initial packets of an ILNP session) that the
    node is operating in the ILNP mode and (2) to prevent off-path
    attacks against ILNP ICMP messages.  This Nonce is used, for
    example, with all ILNP ICMPv6 Locator Update messages that are
    exchanged among ILNP correspondent nodes.
 e) [RFC6745] defines a new ICMPv4 Locator Update message used by an
    ILNP node to inform its correspondent nodes of any changes to its
    set of valid Locators.
 f) [RFC6746] defines a new IPv4 Nonce Option used by ILNPv4 nodes to
    carry a security nonce to prevent off-path attacks against ILNP
    ICMP messages and also defines a new IPv4 Identifier Option used
    by ILNPv4 nodes.
 g) [RFC6747] describes extensions to the Address Resolution Protocol
    (ARP) for use with ILNPv4.
 h) [RFC6748] describes optional engineering and deployment functions
    for ILNP.  These are not required for the operation or use of ILNP
    and are provided as additional options.

1.2. ICMPv6 Locator Update

 As described in [RFC6740] and [RFC6741], an ILNP for IPv6 (ILNPv6)
 node might need to inform correspondent ILNPv6 nodes of changes to
 the set of valid Locator values.  The new ICMPv6 Locator Update
 message described in this document enables an ILNP-capable node to
 update its correspondents about the currently valid set of Locators
 valid to use in reaching the node sending this message [RFC2460]
 [RFC4443].
 This new ICMPv6 message MUST ONLY be used for ILNPv6 sessions.
 Authentication is always required, as described in the Security
 Considerations section later in this note.

Atkinson & Bhatti Experimental [Page 4] RFC 6743 ILNPv6 ICMP November 2012

 Some might consider any and all use of ICMP to be undesirable.  In
 that context, please note that while this specification uses ICMP, on
 grounds that this is a control message, there is no architectural
 difference between using ICMP and using some other framing (for
 example, UDP).

1.3. 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].

2. Syntax

 The ICMPv6 message described in this section has ICMP Type 156 and is
 used ONLY with a current ILNPv6 session.  This message enables an
 ILNPv6 node to inform ILNPv6 correspondent nodes of changes to the
 active Locator set for the ILNPv6 node that originates this message.
 This particular ICMPv6 message MUST ONLY be used with ILNPv6
 sessions.
 This particular ICMPv6 message MUST ONLY be used with ILNPv6
 sessions.  The Checksum field for this message is calculated
 identically as for any other ICMPv6 message.
 ICMPv6 Locator Update message
  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      |     Code      |           Checksum            |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |  Num of Locs  |   Operation   |           RESERVED            |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 /                       Locator [1]                             /
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |        Preference [1]         |           Lifetime [1]        |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 /                       Locator [2]                             /
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |        Preference [2]         |           Lifetime [2]        |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                               .                               |
 |                               .                               |
 |                               .                               |

Atkinson & Bhatti Experimental [Page 5] RFC 6743 ILNPv6 ICMP November 2012

 ICMPv6 Locator Update fields:
    Type                  156
    Code                  0
    Checksum              The 16-bit one's complement of the one's
                          complement sum of the ICMP message, starting
                          with the ICMP Type.  For computing the
                          checksum, the Checksum field is set to 0.
    Num of Locs           The number of 64-bit Locator values that are
                          advertised in this message.  This field MUST
                          NOT be zero.
    Locator[i],           The 64-bit Locator values currently
     i = 1..Num of Locs   valid for the sending ILNPv6 node.
    Preference[i],        The preferability of each Locator[i],
     i = 1..Num of Locs   relative to other valid Locator[i] values.
                          The Preference numbers here are identical,
                          both in syntax and semantics, to the
                          Preference values for L64 records as
                          specified by [RFC6742].
    Lifetime[i]           The maximum number of seconds that this
     i = 1..Num of Locs   particular Locator may be considered valid.
                          Normally, this is identical to the DNS
                          lifetime of the corresponding L64 record, if
                          one exists.
    Operation             The value in this field indicates whether
                          this is a Locator Update Advertisement
                          (0x01) or a Locator Update Acknowledgement
                          (0x02).
    RESERVED              A field reserved for possible future use.
                          At present, the sender MUST initialise this
                          field to zero.  Receivers should ignore this
                          field at present.  The field might be used
                          for some protocol function in future.
 The Operation field has value 1 (hexadecimal 0x01) for a Locator
 Update Advertisement.  The Operation field has value 2 (hexadecimal
 0x02) for a Locator Update Acknowledgement.  All other values of the
 Operation field are reserved for future use by future revisions of
 this specification.

Atkinson & Bhatti Experimental [Page 6] RFC 6743 ILNPv6 ICMP November 2012

 A node whose set of valid Locators has changed MUST send Locator
 Update Advertisement messages to each correspondent node for each
 active unicast ILNP session.  For unicast ILNP sessions, the receiver
 of a valid Locator Update Advertisement (e.g., authentication checks
 all passed; advertisement is received from a current correspondent
 node) addressed to the receiver MUST send a Locator Update
 Acknowledgement back to the sender of the Locator Update
 Advertisement.  The Acknowledgement message body is identical to the
 received Advertisement message body, except for the Operation value.
 All ILNPv6 ICMP Locator Update messages MUST contain a valid ILNPv6
 Identifier option and MUST contain an ILNPv6 Nonce Option.
 ILNPv6 ICMP Locator Update messages also MAY be protected using IP
 Security for ILNP [RFC6741] [RFC4301].  Deployments in high-threat
 environments SHOULD also protect ILNPv6 ICMP Locator Update messages
 using IPsec.  While IPsec Encapsulating Security Payload (ESP) can
 protect a payload, no form of IPsec ESP is able to protect an IPv6
 option that appears prior to the ESP header.
 Note that even when IP Security for ILNP is in use, the ILNP Nonce
 Option still MUST be present.  This simplifies protocol processing,
 and it also means that a receiver can perform the inexpensive check
 of the Nonce value before performing any (potentially expensive)
 cryptographic calculation.

2.1. Example ICMPv6 Locator Update Message

 This example shows the ICMPv6 syntax for the case where 2 Locator
 values are being indicated.
  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      |     Code      |           Checksum            |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |  Num of Locs  |    RESERVED   |           RESERVED            |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 /                       Locator [1]                             /
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |        Preference [1]         |           Lifetime [1]        |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 /                       Locator [2]                             /
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |        Preference [2]         |           Lifetime [2]        |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Atkinson & Bhatti Experimental [Page 7] RFC 6743 ILNPv6 ICMP November 2012

3. Transport Protocol Effects

 This message has no impact on any transport protocol.
 The message may affect where packets for a given transport-layer
 session are sent, but an ILNP design objective is to decouple
 transport-layer protocols and transport-layer session information
 from network-layer changes.

4. Implementation Considerations

 Implementers may use any internal implementation they wish, provided
 that the external appearance is the same as this implementation
 approach.
 To support ILNPv6, and to retain the incremental deployability and
 backwards compatibility needed, the network layer needs a mode bit in
 the Transport Control Block (or its equivalent) to track which IP
 sessions are using the classic IPv6 mode and which IP sessions are
 using the Identifier/Locator Split mode.
 Further, when supporting ILNPv4, nodes will need to support an
 Identifier Locator Communication Cache (ILCC) in the network layer as
 described in [RFC6741].
 A node sending an ICMP Locator Update message MUST include all
 currently valid Locator values in that message.  A node receiving a
 valid ICMP Locator Update message MUST replace the previously current
 set of Locator values for that correspondent node in its own ILCC
 with the newly received set of Locator values.
 Every implementation needs to support a large number of Locator
 values being sent or received in a single ICMP Locator Update
 message, because a multihomed node or multihomed site might have a
 large number of upstream links to different service providers, each
 with its own Locator value.

5. Backwards Compatibility

 This ICMPv6 message uses the same checksum calculations as any other
 ICMPv6 message.
 When ILNPv6 is not in use, the receiving IPv6 mode MUST discard the
 ICMP Locator Update packet without processing the packet.  This is
 standard behaviour for a non-ILNPv6 node when receiving an ICMPv6
 message with an unknown header field value.

Atkinson & Bhatti Experimental [Page 8] RFC 6743 ILNPv6 ICMP November 2012

6. Security Considerations

 Security considerations for the overall ILNP architecture are
 described in [RFC6740].  Additional common security considerations
 are described in [RFC6741].  This section describes security
 considerations specific to ILNPv6 topics discussed in this document.
 The ICMPv6 Locator Update message MUST ONLY be used for ILNPv6
 sessions.
 The ILNP Nonce Destination Option [RFC6744] MUST be present in
 packets containing an ICMPv6 Locator Update message.  Further, the
 received Nonce Destination Option MUST contain the correct nonce
 value for the packet to be accepted by the recipient and then passed
 to the ICMPv6 protocol for processing.  If either of these
 requirements are not met, the received packet MUST be discarded as a
 forgery, and a security event SHOULD be logged by the system
 receiving the non-authentic packet.
 ILNP sessions operating in higher risk environments SHOULD use IP
 Security for ILNP [RFC6741] [RFC4301] *in addition* to the ILNPv6
 Nonce Destination Option.  Use of IP Security for ILNP to protect a
 packet does NOT permit the packet to be sent without the Nonce
 Destination Option.
 Implementations need to support the case where a single ICMP Locator
 Update message contains a large number of Locator and Preference
 values and ought not develop a security fault (e.g., stack overflow)
 due to a received message containing more Locator values than
 expected.
 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].

7. IANA Considerations

 Consistent with the procedures of [RFC4443], IANA has assigned the
 value 156 to the ICMP Type listed in Section 2.

Atkinson & Bhatti Experimental [Page 9] RFC 6743 ILNPv6 ICMP November 2012

8. References

8.1. Normative References

 [RFC2119]   Bradner, S., "Key words for use in RFCs to Indicate
             Requirement Levels", BCP 14, RFC 2119, March 1997.
 [RFC2460]   Deering, S. and R. Hinden, "Internet Protocol, Version 6
             (IPv6) Specification", RFC 2460, December 1998.
 [RFC3704]   Baker, F. and P. Savola, "Ingress Filtering for
             Multihomed Networks", BCP 84, RFC 3704, March 2004.
 [RFC4301]   Kent, S. and K. Seo, "Security Architecture for the
             Internet Protocol", RFC 4301, December 2005.
 [RFC4443]   Conta, A., Deering, S., and M. Gupta, Ed., "Internet
             Control Message Protocol (ICMPv6) for the Internet
             Protocol Version 6 (IPv6) Specification", RFC 4443, March
             2006.
 [RFC6740]   Atkinson, R. and S. Bhatti, "Identifier-Locator Network
             Protocol (ILNP) Architectural Description", RFC 6740,
             November 2012.
 [RFC6741]   Atkinson, R. and S. Bhatti, "Identifier-Locator Network
             Protocol (ILNP) Engineering and Implementation
             Considerations", RFC 6741, November 2012.
 [RFC6744]   Atkinson, R. and S. Bhatti, "IPv6 Nonce Destination
             Option for the Identifier-Locator Network Protocol for
             IPv6 (ILNPv6)", RFC 6744, November 2012.

8.2. Informative References

 [RFC2827]   Ferguson, P. and D. Senie, "Network Ingress Filtering:
             Defeating Denial of Service Attacks which employ IP
             Source Address Spoofing", BCP 38, RFC 2827, May 2000.
 [RFC4984]   Meyer, D., Ed., Zhang, L., Ed., and K. Fall, Ed., "Report
             from the IAB Workshop on Routing and Addressing", RFC
             4984, September 2007.
 [RFC6742]   Atkinson, R., Bhatti, S. and S. Rose, "DNS Resource
             Records for the Identifier-Locator Network Protocol
             (ILNP)", RFC 6742, November 2012.

Atkinson & Bhatti Experimental [Page 10] RFC 6743 ILNPv6 ICMP November 2012

 [RFC6745]   Atkinson, R. and S. Bhatti,  "ICMP Locator Update Message
             for the Identifier-Locator Network Protocol for IPv4
             (ILNPv4)", RFC 6745, November 2012.
 [RFC6746]   Atkinson, R. and S.Bhatti, "IPv4 Options for the
             Identifier Locator Network Protocol (ILNP)", RFC 6746,
             November 2012.
 [RFC6747]   Atkinson, R. and S. Bhatti, "Address Resolution Protocol
             (ARP) Extension for the Identifier-Locator Network
             Protocol for IPv4 (ILNPv4)", RFC 6747, November 2012.
 [RFC6748]   Atkinson, R. and S. Bhatti, "Optional Advanced Deployment
             Scenarios for the Identifier-Locator Network Protocol
             (ILNP)", RFC 6748, November 2012.

9. 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.

Atkinson & Bhatti Experimental [Page 11] RFC 6743 ILNPv6 ICMP November 2012

Authors' Addresses

 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  KY16 9SX
 Scotland, UK
 EMail: saleem@cs.st-andrews.ac.uk

Atkinson & Bhatti Experimental [Page 12]

/data/webs/external/dokuwiki/data/pages/rfc/rfc6743.txt · Last modified: 2012/11/10 00:26 (external edit)