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Versions: (draft-tseng-dhc-isnsoption) 00 01 02 03 04 05 06 07 08 09 10 11 12 13 RFC 4174

        DHC Working Group                                   Charles Monia
        INTERNET DRAFT                                         Josh Tseng
        Expires: March 2004                                 Kevin Gibbons
        Internet Draft
        Document: <draft-ietf-dhc-isnsoption-10.txt>       Nishan Systems
        Category: Standards Track                          September 2003
     
     
              The IPv4 DHCP Option for the Internet Storage Name Service
     
     Status of this Memo
     
        This document is an Internet-Draft and is in full conformance with
        all provisions of Section 10 of [RFC2026].
     
        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 made obsolete 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/ietf/1id-abstracts.txt
     
        The list of Internet-Draft Shadow Directories can be accessed at
        http://www.ietf.org/shadow.html.
     
     Comments
     
        Comments should be sent to the DHCP mailing list (dhcwg@ietf.org) or
        to the authors.
     
                                 Table of Contents
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     Monia, et-al               Standards Track                   [Page 1]
     

     DHCP Option Number for iSNS Revision 10                 September 2003
     
     Status of this Memo...................................................1
     Comments..............................................................1
     Abstract..............................................................3
     Conventions used in this document.....................................3
     1.   Introduction.....................................................3
     2.   iSNS Option for DHCP.............................................4
     2.1  iSNS Functions Field.............................................5
     2.2  Discovery Domain Access Field....................................7
     2.3  Administrative Flags Field.......................................8
     2.4  iSNS Server Security Bitmap......................................9
     3.   Security Considerations.........................................10
     4.   IANA Considerations.............................................11
     5.   Normative References............................................11
     6.   Non-Normative References........................................11
     7.   Author's Addresses..............................................12
     Full Copyright Statement.............................................13
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     Monia, et-al               Standards Track                   [Page 2]
     

     DHCP Option Number for iSNS Revision 10                 September 2003
     
     Abstract
     
        This document describes the DHCP option to allow Internet Storage
        Name Service (iSNS) clients to automatically discover the location
        of the iSNS server through the use of DHCP for IPv4. iSNS provides
        discovery and management capabilities for Internet SCSI (iSCSI) and
        Internet Fibre Channel Protocol (iFCP) storage devices in an
        enterprise-scale IP storage network.  iSNS provides intelligent
        storage management services comparable to those found in Fibre
        Channel networks, allowing a commodity IP network to function in a
        similar capacity as a storage area network.
     
     Conventions used in this document
     
        iSNS refers to the Internet Storage Name Service framework
        consisting of the storage network model and associated services.
     
        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].
     
        All frame formats are in big endian network byte order.  RESERVED
        fields SHOULD be set to zero.
     
        This document uses the following terms:
     
        "iSNS Client" - iSNS clients are processes resident in iSCSI and
        iFCP devices that initiate transactions with the iSNS server using
        the iSNS Protocol.
     
        "iSNS Server" - The iSNS server responds to iSNS protocol query and
        registration messages, and initiates asynchronous notification
        messages.  The iSNS server stores information registered by iSNS
        clients.
     
        "iSCSI (Internet SCSI)" - iSCSI is an encapsulation of SCSI for a
        new generation of storage devices interconnected with TCP/IP.
     
        "iFCP (Internet Fibre Channel Protocol)" - iFCP is a gateway-to-
        gateway protocol designed to interconnect existing Fibre Channel
        devices using TCP/IP.  iFCP maps the Fibre Channel transport and
        fabric services to TCP/IP.
     
     1.       Introduction
     
        The Dynamic Host Configuration Protocol for IPv4 provides a
        framework for passing configuration information to hosts.  Its
        usefulness extends to hosts and devices using the iSCSI and iFCP
        protocols to connect to block level storage assets over a TCP/IP
        network.
     
        The iSNS Protocol provides a framework for automated discovery,
        management, and configuration of iSCSI and iFCP devices on a TCP/IP
        network.  It provides functionality similar to that found on Fibre
     
     Monia, et-al               Standards Track                   [Page 3]
     

     DHCP Option Number for iSNS Revision 10                 September 2003
     
        Channel networks, except that iSNS works within the context of an IP
        network.  iSNS thereby provides the requisite storage intelligence
        to IP networks that are standard on existing Fibre Channel networks.
     
        Existing DHCP options cannot be used to find iSNS servers for the
        following reasons:
     
         a) iSNS functionality is distinctly different from other protocols
            using DHCP options.  Specifically, iSNS provides a significant
            superset of capabilities compared to typical name resolution
            protocols such as DNS.  It is designed to support client devices
            that allow themselves to be configured and managed from a
            central iSNS server
     
         b) iSNS requires a DHCP option format that provides more than the
            location of the iSNS server.  The DHCP option needs to specify
            the subset of iSNS services that may be actively used by the
            iSNS client.
     
        The DHCP option number for iSNS is used by iSCSI and iFCP devices to
        discover the location and role of the iSNS server.  The DHCP option
        number assigned for iSNS by IANA is <<TBD>>.
     
     2.       iSNS Option for DHCP
     
        This option specifies the location of the primary and backup iSNS
        servers and the iSNS services available to an iSNS client.
     
         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
        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
        |   Code = TBD  |    Length     |          iSNS Functions       |
        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
        |           DD Access           |     Administrative FLAGS      |
        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
        |                 iSNS Server Security Bitmap                   |
        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
        |      a1       |       a2      |       a3      |       a4      |
        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
        |      b1       |       b2      |       b3      |       b4      |
        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
        |                            . . . .                            |
        |                 Additional Secondary iSNS Servers             |
        |                            . . . .                            |
        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
                           Figure 1 -- iSNS Server Option
     
        The iSNS Option specifies a list of IP addresses used by iSNS
        servers. The option contains the following parameters:
     
        Length: the number of bytes that follow the Length field.
     
     
     
     
     Monia, et-al               Standards Track                   [Page 4]
     

     DHCP Option Number for iSNS Revision 10                 September 2003
     
        iSNS Functions: A bitmapped field defining the functions supported
                by the iSNS servers.  The format of this field is described
                in section 2.1.
     
        Discovery Domain Access: A bit field indicating the types of iSNS
                clients that are allowed to modify Discovery Domains. The
                field contents are described in section 2.2.
     
        Administrative Flags field: Contains the administrative settings for
                the iSNS servers discovered through the DHCP query.  The
                contents of this field are described in section 2.3.
     
        iSNS Server Security Bitmap: Contains the iSNS server security
                settings specified in section 2.4.
     
        a1...a4: Depending on the setting of the Heartbeat bit in the
                Administrative Flags field (see section 2.3), this field
                contains either the IP address from which the iSNS heartbeat
                originates (see [ISNS]) or the IP address of the primary
                iSNS server.
     
        b1...b4: Depending on the setting of Heartbeat bit in the
                Administrative Flags field (see section 2.3), this field
                contains either the IP address of the primary iSNS server or
                a secondary iSNS server.
     
        Additional Secondary iSNS Servers: Each set of four octets specifies
                the IP address of a secondary iSNS server.
     
        The Code field through IP address field a1...a4 MUST be present in
        every response to the iSNS query, hence the Length field has a
        minimum value of 14.
     
        If the Heartbeat bit is set in the Administrative Flags field (see
        section 2.3), then b1...b4 MUST also be present. In this case, the
        minimum value of the Length field is 18.
     
        The inclusion of Additional Secondary iSNS Servers in the response
        MUST be indicated by increasing the Length field accordingly.
     
     2.1      iSNS Functions Field
     
        The iSNS Functions Field defines the iSNS server's operational role
        (i.e., how the iSNS server is to be used).  The iSNS server's role
        can be as basic as providing simple discovery information, or as
        significant as providing IKE/IPSec security policies and
        certificates for the use of iSCSI and iFCP devices. The format of
        the iSNS Functions field is shown in Figure 2:
     
     
     
     
     
     
     
     Monia, et-al               Standards Track                   [Page 5]
     

     DHCP Option Number for iSNS Revision 10                 September 2003
     
                      0                   1         1
                      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
                     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
                     |       Reserved          |S|A|E|
                     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
                     Figure 2 -- iSNS Functions Field
     
                Bit field     Significance
                ---------     ------------
                15            Function Fields Enabled
                14            DD-Based Authorization
                13            Security Policy Distribution
     
        iSNS Functions Field definitions:
     
     
                Function Fields This bit specifies the validity of the
                Enabled:        remaining iSNS Function fields.  If set to
                                 one, then the contents of all other iSNS
                                 Function fields are valid.  If set to zero,
                                 then the contents of all other iSNS
                                 Function fields MUST be ignored.
     
                DD-based        Indicates whether or not devices in a
                Authorization:  common Discovery Domain (DD) are implicitly
                                 authorized to access one another. Although
                                 Discovery Domains control the scope of
                                 device discovery, they do not necessarily
                                 indicate whether or not a domain member is
                                 authorized to access discovered devices.
                                 If this bit is set to one, then devices in
                                 a common Discovery Domain are automatically
                                 allowed access to each other (if
                                 successfully authenticated).  If this bit
                                 is set to zero, then access authorization
                                 is not implied by domain membership and
                                 must be explicitly performed by each
                                 device. In either case, devices not in a
                                 common discovery domain are not allowed to
                                 access each other.
     
                Security Policy Indicates whether the iSNS client is to
                Distribution:   download and use the security policy
                                 configuration stored in the iSNS server.
                                 If set to one, then the policy is stored in
                                 the iSNS server and must be used by the
                                 iSNS client for its own security policy.
                                 If set to zero, then the iSNS client must
                                 obtain its security policy configuration by
                                 other means.
     
     
     
     
     
     Monia, et-al               Standards Track                   [Page 6]
     

     DHCP Option Number for iSNS Revision 10                 September 2003
     
     2.2      Discovery Domain Access Field
     
        The format of the DD Access bit field is shown in Figure 3:
     
                       0                               1
                       0   1   2   3   4   5   6  ...  5
                     +---+---+---+---+---+---+---+---+---+
                     | if| tf| is| ts| C | E |  Reserved |
                     +---+---+---+---+---+---+---+---+---+
                    Figure 3 -- Discovery Domain Access Field
     
                 Bit field  Significance
                 ---------  ------------
                      5      Enabled
                      4      Control Node
                      3      iSCSI Target
                      2      iSCSI Initiator
                      1      iFCP Target Port
                      0      iFCP Initiator Port
     
     
        Discovery Domain Access Field Definitions:
     
                Enabled:           This bit specifies the validity of the
                                   remaining DD Access bit fields.  If this
                                   bit is set to one, then the contents of
                                   the remainder of the DD Access field are
                                   valid.  If this bit is set to zero, then
                                   the contents of the remainder of this
                                   field MUST be ignored.
     
                Control Node:      Specifies whether the iSNS server allows
                                   Discovery Domains to be added, modified
                                   or deleted by means of Control Nodes. If
                                   set to one, then Control Nodes are
                                   allowed to modify the Discovery Domain
                                   configuration.  If set to zero, then
                                   Control Nodes are not allowed to modify
                                   Discovery Domain configurations.
     
                iSCSI Target,      These bits determine whether the
                iSCSI Initiator,   respective registered iSNS client
                iFCP Target Port,  (determined by iSCSI Node Type or iFCP
                iFCP Initiator     Port Role) is allowed to add, delete, or
                Port:              modify Discovery Domains.  If set to
                                   one, then modification by the specified
                                   client type is allowed. If set to zero,
                                   then modification by the specified
                                   client type is not allowed.
     
                                   (A node may implement multiple node
                                   types.)
     
     
     
     Monia, et-al               Standards Track                   [Page 7]
     

     DHCP Option Number for iSNS Revision 10                 September 2003
     
     2.3      Administrative Flags Field
     
        The format of the Administrative Flags bit field is shown in
        Figure 4:
     
                           0                   1         1
                           0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
                          +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
                          |    RESERVED           |D|M|H|E|
                          +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
                           Figure 4 -- Administrative Flags
     
                            Bit Field      Significance
                            ---------      ------------
                                15          Enabled
                                14          Heartbeat
                                13          Management SCNs
                                12          Default Discovery Domain
     
     
        Administrative Flags Field definitions:
     
                Enabled:           Specifies the validity of the remainder
                                   of the Administrative Flags field.  If
                                   set to one, then the contents of the
                                   remaining Administrative Flags are
                                   valid.  If set to zero, then the
                                   remaining contents MUST be ignored,
                                   indicating that iSNS administrative
                                   settings are obtained through means
                                   other than DHCP.
     
                Heartbeat:         Indicates whether the first IP address
                                   is the multicast address to which the
                                   iSNS heartbeat message is sent.  If set
                                   to one, then a1-a4 contains the
                                   heartbeat multicast address and b1-b4
                                   contains the IP address of the primary
                                   iSNS server, followed by the IP
                                   address(es) of any backup servers (see
                                   Figure 1).  If set to zero, then a1-a4
                                   contains the IP address of the primary
                                   iSNS server, followed by the IP
                                   address(es) of any backup servers.
     
                Management SCNs:   Indicates whether control nodes are
                                   authorized to register to receive
                                   Management State Change Notifications
                                   (SCN's).  Management SCN's are a special
                                   class of State Change Notification whose
                                   scope is the entire iSNS database.  If
                                   set to one, then control nodes are
                                   authorized to register to receive
                                   Management SCN's.  If set to zero, then
     
     Monia, et-al               Standards Track                   [Page 8]
     

     DHCP Option Number for iSNS Revision 10                 September 2003
     
                                   control nodes are not authorized to
                                   receive Management SCN's (although they
                                   may receive normal SCN's).
     
                Default Discovery  Indicates whether a newly registered
                Domain:            device that is not explicitly placed
                                   into a Discovery Domain (DD) and
                                   Discovery Domain Set (DDS) should be
                                   automatically placed into a default DD
                                   and DDS.  If set to one, then a default
                                   DD shall contain all devices in the iSNS
                                   database that have not been explicitly
                                   placed into a DD by an iSNS client.  If
                                   set to zero, then devices not explicitly
                                   placed into a DD are not members of any
                                   DD.
     
     
     
     2.4      iSNS Server Security Bitmap
     
        The format of the iSNS server security Bitmap field is shown in
        Figure 5. If valid, this field communicates to the DHCP client the
        security settings that are required to communicate with the
        indicated iSNS server.
     
         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
        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
        |                     Reserved                    |T|X|P|A|M|S|E|
        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
                      Figure 5 -- iSNS Server Security Bitmap
     
                Bit Field     Significance
                ---------     ----------------
                     31      Enabled
                     30      IKE/IPSec
                     29      Main Mode
                     28      Aggressive Mode
                     27      PFS
                     26      Transport Mode
                     25      Tunnel Mode
     
     
        iSNS Server Security Bitmap definitions:
     
     
     
     
     
     
     
     
     
     
     Monia, et-al               Standards Track                   [Page 9]
     

     DHCP Option Number for iSNS Revision 10                 September 2003
     
                Enabled          This bit specifies the validity of the
                                  remainder of the iSNS server security
                                  bitmap.  If set to one, then the contents
                                  of the remainder of the field are valid.
                                  If set to zero, then the contents of the
                                  rest of the field are undefined and MUST
                                  be ignored.
     
                IKE/IPSec        1 = IKE/IPSec enabled; 0 = IKE/IPSec
                                  disabled.
     
                Main Mode        1 = Main Mode enabled; 0 = Main Mode
                                  disabled.
     
                Aggressive Mode  1 = Aggressive mode enabled; 0 =
                                  Aggressive mode disabled.
     
                PFS              1 = PFS enabled; 0 = PFS disabled.
     
                Transport Mode   1 = Transport mode preferred; 0 = No
                                  preference.
     
                Tunnel Mode      1 = Tunnel mode preferred; 0 = No
                                  preference.
     
     
     
        If IKE/IPSec is disabled, this indicates that the Internet Key
        Exchange (IKE) Protocol is not available to configure IPSec keys for
        iSNS sessions to this iSNS server.  It does not necessarily preclude
        other key exchange methods (e.g., manual keying) from establishing
        an IPSec security association for the iSNS session.
     
        If IKE/IPsec is enabled, an implementation SHALL enable:
     
        a) One of Main Mode or Aggressive Mode but not both and
     
        b) One of Transport Mode or Tunnel Mode but not both.
     
     3.       Security Considerations
     
        DHCP security considerations are addressed in [RFC3118].  Among
        these is the potential for a "man-in-the-middle" attack by a hostile
        entity modifying or replacing the original iSNS option message.
        Unless some form of authentication is implemented, an attacker may
        trick the iSNS client into connecting into rogue iSNS servers.
     
        To thwart such attacks, the DHCP response should be verified in some
        manner. One approach is direct authentication via [RFC3118], when
        implemented.  Since this technology is not widely deployed, an
        alternative is to authenticate the discovered iSNS server through
        use of IPSec or the iSNS authentication block as described in
        [ISNS]. Of course, use of iSNS Server authentication implies a site
     
     
     Monia, et-al               Standards Track                  [Page 10]
     

     DHCP Option Number for iSNS Revision 10                 September 2003
     
        wide policy requiring use of one of the authentication methods
        specified in [ISNS] by all iSNS servers.
     
        If no authentication is used and it is determined that the potential
        exists for one of the attacks described in [RFC3118], then the DHCP
        option message for iSNS should not be utilized.
     
     4.       IANA Considerations
     
        In accordance with the policy defined in [DHCP], IANA has assigned a
        value of TBD for this option.
     
        There are no other IANA-assigned values defined by this
        specification.
     
     5.       Normative References
     
            [DHCP]  Droms, R., "Dynamic Host Configuration Protocol", RFC
                    2131, Bucknell University, March 1997.
     
            [iSNS]  Tseng, J. et al., "iSNS - Internet Storage Name
                    Service", Internet draft (work in progress), draft-ietf-
                    ips-isns-12.txt, August 2002
     
            [RFC2026] Bradner, S., "The Internet Standards Process --
                    Revision 3", BCP 9, RFC 2026, October 1996
     
            [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
                    Requirement Levels", BCP 14, RFC 2119, March 1997
     
            [RFC3118] Arbaugh, W., Droms, R., "Authentication for DHCP
                    Messages", RFC 3118, June 2001
     
     
     
     6.       Non-Normative References
     
            [iFCP]  Monia, C., et al., "iFCP - A Protocol for Internet Fibre
                    Channel Storage Networking", Internet draft (work in
                    progress), draft-ietf-ips-ifcp-13.txt, May 2002
     
            [iSCSI] Satran, J., et al., "iSCSI", Internet draft (work in
                    progress), draft-ietf-ips-iSCSI-15.txt, August 2002
     
            [SEC-IPS] Aboba, B., et al., "Securing IP Block Storage
                    Protocols", draft-ietf-ips-security-14.txt, June 2002
     
     
     
     
     
     
     
     
     
     Monia, et-al               Standards Track                  [Page 11]
     

                      Internet Storage Name Service (iSNS)    November 2001
     
     7.       Author's Addresses
     
        Kevin Gibbons,
        Charles Monia,
        Josh Tseng
     
        Nishan Systems
        3850 North First Street
        San Jose, CA 95134-1702
        Phone: (408) 519-3700
        Email: cmonia@nishansystems.com
               jtseng@nishansystems.com
               kgibbons@nishansystems.com
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     Monia, et-al               Standards Track                  [Page 12]
     

     Full Copyright Statement
     
        "Copyright (C) The Internet Society September 2003. All Rights
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        The limited permissions granted above are perpetual and will not be
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