Internet Draft R. Atkinson draft-rja-ilnp-icmp-00.txt Extreme Networks Category: Experimental Expires: 10 June 2009 10 December 2008 ICMP Locator Update message draft-rja-ilnp-icmp-00.txt Status of this Memo Distribution of this memo is unlimited. 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/1id-abstracts.html The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This document is a contribution to the IRTF Routing Research Group. It is neither a contribution to the IETF, nor to any IETF Working Group, nor to any IETF Area. Abstract This describes an experimental ICMPv6 message type to dynamically update Identifier/Locator bindings for an Identifier Locator Network Protocol based upon IPv6. Atkinson Expires in 6 months [Page 1] Internet Draft ILNP ICMP 10 DEC 2008 Table of Contents 1. Introduction ...........................................2 2. Syntax..................................................3 3. Transport Protocol Effects..............................4 4. Backwards Compatibility.................................4 5. Security Considerations ................................5 6. IANA Considerations ....................................5 7. References .............................................6 1. Introduction At present, the IRTF Routing Research Group is studying different approaches to evolving the Internet Architecture. Several different classes of evolution are being considered. 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 evoluationary approaches. In particular, the Identifier-Locator Network Protocol being described in this document and related Internet-Drafts is an evolution of IPv6. [ILNP- Intro] [ILNP-Nonce] [ILNP-DNS] [RFC-2460] The new ICMPv6 Locator Update message described in this document enables an enhanced node to update its correspondents about the currently valid set of Locators valid for use to reaching the node sending this message. This new ICMPv6 message must not be used for IP sessions operating in classic IPv6 mode; it must only be used for IP sessions that are operating in Identifier/Locator Split mode. 2. Syntax ------------------------------------------------------------ | ICMP Type | ICMP Code | Checksum | +-------------+---------------+-------------+--------------+ | Num of Locs | RESERVED FOR FUTURE USE | +-------------+---------------+-------------+--------------+ / Locator / +-------------+---------------+-------------+--------------+ ICMP Type: This 8-bit field is set to a value that indicates this is a Locator Update message. Atkinson Expires in 6 months [Page 2] Internet Draft ILNP ICMP 10 DEC 2008 ICMP Code: This 8-bit field indicates which kind of ICMP Locator Update this is. At present, the only valid value is 0, which means that this message contains all currently valid Locator values for the sending node. Checksum: This contains the ICMPv6 Checksum value for this packet. Num of Locs: This field contains the number of 64-bit Locators that follow the RESERVED field. This field must not contain the number zero, as each ILNP node needs to be reachable via at least 1 Locator value. Multi-homed nodes will have at least 2 Locator values. Reserved: This 24-bit field must be sent as zero. At this time, recipients should ignore the contents of this field, as these bits are reserved for future use. Locator: This 64-bit field contains a valid Locator that can be used to reach the sending node. A variable number of Locator fields are concatenated one after another. These are listed in priority order, with the first Locator field containing the most preferred Locator value. 3. Transport Protocol Effects This message has no impact on any transport protocol. The message may affect where packets for a given transport session are sent, but one of the design objectives for the I/L Split Mode (ILNP) is to decouple transport-protocols 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 the Identifier/Locator Split operating mode, and 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 Atkinson Expires in 6 months [Page 3] Internet Draft ILNP ICMP 10 DEC 2008 the classic IPv6 mode and which IP sessions are using the Identifier/Locator Split mode. Further, when in the Identifier/Locator Split mode, nodes will need to retain a Correspondent Cache in the network layer that contains for each correspondent node: - Source Identifier(s) in use - Source Locator(s) in use - Destination Identifier(s) in use - Destination Locator(s) in use - Session Nonce value from Local Node to Correspondent Node - Session Nonce value from Correspondent Node to Local Node 5. Backwards Compatibility For all sessions operating in Identifier/Locator Split mode, inside each node the high-order 64-bits ("Locator") are always set to zero before the packet is sent upwards to the transport protocol. So any changes in Locator values used on the wire will be invisible to the transport protocol. In this mode, transport-layer checksums (e.g. TCP pseudo-header checksum) will be calculated with both Source Locator and Destination Locator fields set to all zero. For nodes or sessions not operating in Identifier/Locator Split mode, the ICMP Locator Update packet must be discarded by the recipient without being processed. Atkinson Expires in 6 months [Page 4] Internet Draft ILNP ICMP 10 DEC 2008 6. Security Considerations The ICMP Locator Update message must only be used for IP sessions operating in the Identifier/Locator Split mode. The experimental Nonce Destination Option [ILNP-Nonce] 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. [ Copy some text from -ilnp-intro's Security Considerations to here ] For sessions operating in higher risk environments, the use of the IP Authentication Header *in addition* to the experimental Nonce Destination Option is recommended. 7. IANA Considerations (To be written later) 8. References 8.1. Normative References [RFC-2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC-2460] S. Deering & R. Hinden, "Internet Protocol Version 6 Specification", RFC-2460, December 1998. 8.2. Informative References [ILNP-Intro] Atkinson, R, "ILNP Concept of Operations", draft-rja-ilnp-intro-01.txt, June 2008. [ILNP-DNS] Atkinson, R, "Additional DNS Resource Records", draft-rja-ilnp-dns-00.txt, June 2008. [ILNP-Nonce] Atkinson, R, "Nonce Destination Option", draft-rja-ilnp-nonce-00.txt, June 2008. (Additional references to be added later.) Author's Address Atkinson Expires in 6 months [Page 5] Internet Draft ILNP ICMP 10 DEC 2008 R. Atkinson Extreme Networks 3585 Monroe Street Santa Clara, CA 95051 USA +1 (408)579-2800 rja@extremenetworks.com Atkinson Expires in 6 months [Page 6] Internet Draft ILNP ICMP 10 DEC 2008 Full Copyright Statement Copyright (C) The IETF Trust (2008). 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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. This document may not be modified, and derivative works of it may not be created. This document may only be posted in an Internet-Draft. Atkinson Expires in 6 months [Page 7] Internet Draft ILNP ICMP 10 DEC 2008 Expires: 10 June 2009 Atkinson Expires in 6 months [Page 8]