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Internet Engineering Task Force (IETF)                          D. BlackRequest for Comments: 6172                                           EMCUpdates:4172                                                D. PetersonCategory: Standards Track                                        BrocadeISSN: 2070-1721                                               March 2011Deprecation of the Internet Fibre Channel Protocol (iFCP)Address Translation ModeAbstract   Changes to Fibre Channel have caused the specification of the   Internet Fibre Channel Protocol (iFCP) address translation mode to   become incorrect.  Due to the absence of usage of iFCP address   translation mode, it is deprecated by this document.  iFCP address   transparent mode remains correctly specified.   iFCP address transparent mode has been implemented and is in current   use; therefore, it is not affected by this document.   This document also records the state of Protocol Number 133, which   was allocated for a pre-standard version of the Fibre Channel   Internet Protocol (FCIP).Status of This Memo   This is an Internet Standards Track document.   This document is a product of the Internet Engineering Task Force   (IETF).  It represents the consensus of the IETF community.  It has   received public review and has been approved for publication by the   Internet Engineering Steering Group (IESG).  Further information on   Internet Standards is available inSection 2 of RFC 5741.   Information about the current status of this document, any errata,   and how to provide feedback on it may be obtained athttp://www.rfc-editor.org/info/rfc6172.Black & Peterson             Standards Track                    [Page 1]

RFC 6172              iFCP and Protocol 133 Updates           March 2011Copyright Notice   Copyright (c) 2011 IETF Trust and the persons identified as the   document authors.  All rights reserved.   This document is subject toBCP 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.  Code Components extracted from this document must   include Simplified BSD License text as described in Section 4.e of   the Trust Legal Provisions and are provided without warranty as   described in the Simplified BSD License.Table of Contents1. Introduction...................................................32. Conventions Used in This Document..............................33. iFCP Address Translation Mode..................................33.1. Problem Discussion........................................43.2. iFCP Address Translation Mode Deprecation.................44. FCIP and Protocol Number 133...................................55. Security Considerations........................................56. IANA Considerations............................................57. Conclusions....................................................58. References.....................................................58.1. Normative References......................................58.2. Informative References....................................69. Acknowledgments ...............................................6Black & Peterson             Standards Track                    [Page 2]

RFC 6172              iFCP and Protocol 133 Updates           March 20111.  Introduction   SeeSection 3 of [RFC4172] for introductory material on Fibre Channel   concepts.   The Internet Fibre Channel Protocol (iFCP) [RFC4172] operates in two   modes with respect to Fibre Channel N_PORT fabric addresses (24-bit   N_PORT_IDs): address transparent mode and address translation mode   (both modes are specified in [RFC4172]):   o  Address transparent mode is a pass-through mode that preserves      Fibre Channel N_PORT fabric addresses.   o  Address translation mode is a Fibre Channel analog to Network      Address Translation (NAT) in which iFCP gateways change Fibre      Channel N_PORT fabric addresses at the boundary between Fibre      Channel and the Internet.  Both the source (S_ID) and destination      (D_ID) N_PORT fabric addresses may be changed by the iFCP      gateways.   This document deprecates iFCP address translation mode because the   specification has not tracked changes in Fibre Channel and because   there are no known implementations.   Protocol Number 133 was allocated for a pre-standard version of the   Fibre Channel Internet Protocol (FCIP) that encapsulated FC frames   directly in IP packets.  That protocol number is not used by the   standard FCIP protocol [RFC3821] [FC-BB-3], but implementations of   the pre-standard protocol were deployed.  Therefore, this document   makes no change to the current allocation of Protocol Number 133.2.  Conventions Used in This Document   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].3.  iFCP Address Translation Mode   iFCP address translation mode has to translate addresses embedded in   transmitted data.  This is analogous to NAT translation of IP   addresses embedded in IP packets.  Fibre Channel restricts the   occurrence of embedded fabric addresses to control messages (frames);   N_PORTs send and receive two types of control frames that may contain   embedded fabric addresses:Black & Peterson             Standards Track                    [Page 3]

RFC 6172              iFCP and Protocol 133 Updates           March 2011   o  Extended Link Services (ELSs); and   o  FC-4 Link Services (FC-4 LSs) for the Small Computer System      Interface (SCSI) over Fibre Channel Protocol (FCP).   The embedded fabric address translations for N_PORT control frames   are specified inSection 7.3 of [RFC4172].  These translations were   correct as specified for Fibre Channel as of approximately 2003,   based on the [FC-FS] standard for ELSs and the [FCP] standard for FCP   FC-4 LSs.3.1.  Problem Discussion   Significant changes have been made to FC control frames since the   iFCP specification [RFC4172] was published; the currently applicable   FC standards are [FC-LS] and [FCP-3], and additional changes are   forthcoming in the [FC-LS-2] and [FCP-4] standards projects, which   are nearing completion.  These changes have causedSection 7.3 of   [RFC4172] to become incorrect.   Actual iFCP deployment has diverged significantly from that   anticipated during the development of [RFC4172].  All deployments of   iFCP known to the authors of this document use iFCP address   transparent mode and are used only for FC inter-switch links.  iFCP   address translation mode as specified in [RFC4172] cannot be used for   FC inter-switch links because the necessary embedded fabric address   translations for FC inter-switch control messages (Switch Fabric   Internal Link Services (ILSs)) have not been specified.3.2.  iFCP Address Translation Mode Deprecation   For the reasons described above, it is prudent to deprecate iFCP   address translation mode in preference to updating it to the current   state of Fibre Channel standards.  Updating iFCP address translation   mode would create a continuing requirement to update an unused   protocol mode to match future changes to FC control frames.   Therefore, this document deprecates iFCP address translation mode:   o  iFCP address translation mode [RFC4172] SHOULD NOT be implemented      and SHOULD NOT be used.   o  The status of [RFC4172] remains Proposed Standard RFC in order to      retain the specification of iFCP address transparent mode.   o  The [RFC4172] specification of iFCP address translation mode      should be treated as Historic [RFC2026].Black & Peterson             Standards Track                    [Page 4]

RFC 6172              iFCP and Protocol 133 Updates           March 20114.  FCIP and Protocol Number 133   Protocol Number 133 was allocated for Fibre Channel (FC) [IANA-IP]   and used by a pre-standard version of the FCIP protocol that   encapsulates FC frames directly in IP packets.  The standard FCIP   protocol [RFC3821] [FC-BB-3] encapsulates FC frames in TCP and hence   does not use Protocol Number 133, but implementations of the pre-   standard version of the FCIP protocol were deployed [MR].  Based on   this deployment, the protocol number needs to remain allocated.5.  Security Considerations   The security considerations for iFCP continue to apply; seeSection10 of [RFC4172].6.  IANA Considerations   IANA has added this document as a supplemental reference for the   allocation of Protocol Number 133 but hasn't changed that allocation.7.  Conclusions   For the reasons described in this document, iFCP Address Translation   mode is deprecated, and the allocation of Protocol Number 133 remains   unchanged at this time.8.  References8.1.  Normative References   [FC-FS]   Fibre Channel Framing and Signaling Interface (FC-FS), ANSI             INCITS 373-2003, October 2003.   [FC-LS]   Fibre Channel - Link Services (FC-LS), ANSI INCITS             433-2007, July 2007.   [FCP]     Fibre Channel Protocol (FCP), ANSI INCITS 269-1996, April             1996.   [FCP-3]   Fibre Channel Protocol - 3 (FCP-3), ISO/IEC 14776-223:2008,             June 2008.   [IANA-IP] Assigned Internet Protocol Numbers, IANA Registry,http://www.iana.org, visited October 2010.   [RFC2026] Bradner, S., "The Internet Standards Process -- Revision             3",BCP 9,RFC 2026, October 1996.Black & Peterson             Standards Track                    [Page 5]

RFC 6172              iFCP and Protocol 133 Updates           March 2011   [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate             Requirement Levels",BCP 14,RFC 2119, March 1997.   [RFC4172] Monia, C., Mullendore, R., Travostino, F., Jeong, W., and             M. Edwards, "iFCP - A Protocol for Internet Fibre Channel             Storage Networking",RFC 4172, September 2005.8.2.  Informative References   [FC-BB-3] Fibre Channel Backbone - 3 (FC-BB-3), ANSI INCITS 414-2006,             July 2006.   [FC-LS-2] Fibre Channel - Link Services - 2 (FC-LS-2), INCITS Project             2103-D, Technical Committee T11 (www.t11.org).   [FCP-4]   Fibre Channel Protocol - 4 (FCP-4), INCITS Project 1828-D,             Technical Committee T10 (www.t10.org).   [MR]      Rajagopal, M., Private email communication, June 2009.   [RFC3821] Rajagopal, M., Rodriguez, E., and R. Weber, "Fibre Channel             Over TCP/IP (FCIP)",RFC 3821, July 2004.9.  Acknowledgments   The authors would like to thank Tom Talpey, David Harrington, Joe   Touch, Paul Hoffman, and Pekka Savola for helpful comments on this   document.Authors' Addresses   David L. Black   EMC Corporation   176 South Street   Hopkinton, MA 01748   Phone: +1 (508) 293-7953   EMail: david.black@emc.com   David Peterson   Brocade Communications   6000 Nathan Lane North   Plymouth, MN 55442   Phone: +1 (612) 802-3299   EMail: david.peterson@brocade.comBlack & Peterson             Standards Track                    [Page 6]