rfc4544.txt

一个学习iSCSI协议的文档

Network Working Group                                           M. Bakke
Request for Comments: 4544                                 Cisco Systems
Category: Standards Track                                     M. Krueger
                                                         Hewlett-Packard
                                                            T. McSweeney
                                                                     IBM
                                                               J. Muchow
                                                            Qlogic Corp.
                                                                May 2006


                    Definitions of Managed Objects
          for Internet Small Computer System Interface (iSCSI)

Status of This Memo

   This document specifies an Internet standards track protocol for the
   Internet community, and requests discussion and suggestions for
   improvements.  Please refer to the current edition of the "Internet
   Official Protocol Standards" (STD 1) for the standardization state
   and status of this protocol.  Distribution of this memo is unlimited.

Copyright Notice

   Copyright (C) The Internet Society (2006).

Abstract

   This memo defines a portion of the Management Information Base (MIB)
   for use with network management protocols in TCP/IP-based internets.
   In particular, it defines objects for managing a client using the
   Internet Small Computer System Interface (iSCSI) protocol (SCSI over
   TCP).


















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RFC 4544                       iSCSI MIB                        May 2006


Table of Contents

   1. Introduction ....................................................3
   2. Specification of Requirements ...................................3
   3. The Internet-Standard Management Framework ......................3
   4. Relationship to Other MIB Modules ...............................3
   5. Relationship to SNMP Contexts ...................................4
   6. Discussion ......................................................4
      6.1. iSCSI MIB Object Model .....................................5
      6.2. iSCSI MIB Table Structure ..................................6
      6.3. iscsiInstance ..............................................7
      6.4. iscsiPortal ................................................7
      6.5. iscsiTargetPortal ..........................................9
      6.6. iscsiInitiatorPortal .......................................9
      6.7. iscsiNode .................................................10
      6.8. iscsiTarget ...............................................10
      6.9. iscsiTgtAuthorization .....................................11
      6.10. iscsiInitiator ...........................................11
      6.11. iscsiIntrAuthorization ...................................11
      6.12. iscsiSession .............................................11
      6.13. iscsiConnection ..........................................12
      6.14. IP Addresses and TCP Port Numbers ........................12
      6.15. Descriptors: Using OIDs in Place of Enumerated Types .....13
      6.16. Notifications ............................................13
   7. MIB Definitions ................................................14
   8. Security Considerations ........................................79
   9. IANA Considerations ............................................80
   10. Normative References ..........................................80
   11. Informative References ........................................81
   12. Acknowledgements ..............................................81





















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RFC 4544                       iSCSI MIB                        May 2006


1.  Introduction

   This document defines a MIB module for iSCSI [RFC3720], used to
   manage devices that implement the iSCSI protocol.

2.  Specification of Requirements

   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 RFC 2119 [RFC2119].

3.  The Internet-Standard Management Framework

   For a detailed overview of the documents that describe the current
   Internet-Standard Management Framework, please refer to section 7 of
   RFC 3410 [RFC3410].

   Managed objects are accessed via a virtual information store, termed
   the Management Information Base or MIB.  MIB objects are generally
   accessed through the Simple Network Management Protocol (SNMP).
   Objects in the MIB are defined using the mechanisms defined in the
   Structure of Management Information (SMI).  This memo specifies a MIB
   module that is compliant to the SMIv2, which is described in STD 58,
   RFC 2578 [RFC2578], STD 58, RFC 2579 [RFC2579] and STD 58, RFC 2580
   [RFC2580].

4.  Relationship to Other MIB Modules

   The iSCSI MIB module is normally layered between the SCSI MIB module
   [RFC4455] and the TCP MIB module [RFC4022], and makes use of the IP
   Storage (IPS) Identity Authentication MIB module [RFC4545].  Here is
   how these modules are related:

   SCSI MIB  Within systems where a SCSI layer is present, each
             iscsiNode, whether it has an initiator role, target role,
             or both, is related to one SCSI device within the SCSI MIB
             module.  In this case, the iscsiNodeTransportType attribute
             points to the SCSI transport object within the SCSI MIB
             module, which in turn contains an attribute that points
             back to the iscsiNode.  In this way, a management station
             can navigate between the two MIB modules.  In systems where
             a SCSI layer is not present, such as within an iSCSI proxy
             device, the iscsiNodeTransportType attribute points to the
             appropriate corresponding object within the appropriate
             MIB, or is left blank.






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   TCP MIB   Each iSCSI connection is related to one transport-level
             connection.  Currently, iSCSI uses only TCP; the iSCSI
             connection is related to a TCP connection using its normal
             (protocol, source address, source port, destination
             address, destination port) 5-tuple.

   AUTH MIB  Each iSCSI node that serves a target role can have a list
             of authorized initiators.  Each of the entries in this list
             points to an identity within the IPS Identity
             Authentication MIB module that will be allowed to access
             the target.  iSCSI nodes that serve in an initiator role
             can also have a list of authorized targets.  Each of the
             entries in this list points to an identity within the Auth
             MIB module to which the initiator should attempt to
             establish sessions.  The Auth MIB module includes
             information used to identify initiators and targets by
             their iSCSI name, IP address, and/or credentials.

   This MIB module imports objects from RFCs 2578 [RFC2578], 2579
   [RFC2579], 2580 [RFC2580], and 3411 [RFC3411].  It also imports
   textual conventions from the INET-ADDRESS-MIB [RFC4001].

5.  Relationship to SNMP Contexts

   Each non-scalar object in the iSCSI MIB module is indexed first by an
   iSCSI Instance.  Each instance is a collection of nodes, portals,
   sessions, etc., that can define a physical or virtual partitioning of
   an iSCSI-capable device.  The use of an instance works well with
   partitionable or hierarchical storage devices and fits in logically
   with other management schemes.  Instances do not replace SNMP
   contexts, however they do provide a very simple way to assign a
   virtual or physical partition of a device to one or more SNMP
   contexts, without having to do so for each individual node, portal,
   and session row.

6.  Discussion

   This MIB module structure supplies configuration, fault, and
   statistics information for iSCSI devices [RFC3720].  It is structured
   around the well-known iSCSI objects, such as targets, initiators,
   sessions, connections, and the like.

   This MIB module may also be used to configure access to iSCSI
   targets, by creating iSCSI Portals and authorization list entries.







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RFC 4544                       iSCSI MIB                        May 2006


   It is worthwhile to note that this is an iSCSI MIB module and as such
   reflects only iSCSI objects.  This module does not contain
   information about the SCSI-layer attributes of a device.  If a SCSI
   layer is present, the SCSI MIB module, currently under development,
   may be used to manage SCSI information for a device.

   The iSCSI MIB module consists of several "objects", each of which is
   represented by one or more tables.  This section contains a brief
   description of the "object" hierarchy and a description of each
   object, followed by a discussion of the actual table structure within
   the objects.

6.1.  iSCSI MIB Object Model

   The top-level object in this structure is the iSCSI instance, which
   "contains" all of the other objects.

   iscsiInstance
      -- A distinct iSCSI entity within the managed system.
      iscsiPortal
         -- An IP address used by this instance
         iscsiTargetPortal
            -- Contains portal information relevant when the portal
            -- is used to listen for connections to its targets.
         iscsiInitiatorPortal
            -- Contains portal information relevant when the portal
            -- is used to initiate connections to other targets.
      iscsiNode
         -- An iSCSI node can act as an initiator, a target, or both.
         -- Contains generic (non-role-specific) information.
         iscsiTarget
            -- Target-specific iSCSI node information.
            iscsiTgtAuth
               -- A list of initiator identities that are allowed
               -- access to this target.
         iscsiInitiator
            -- Initiator-specific iSCSI node information.
            iscsiIntrAuth
               -- A list of target identities to which this initiator
               -- is configured to establish sessions.
         iscsiSession
            -- An active iSCSI session between an initiator and target.
            -- The session's direction may be Inbound (outside
            -- initiator to our target) or Outbound (our initiator to
            -- an outside target).
            iscsiConnection
               -- An active TCP connection within an iSCSI session.




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   An iSCSI node can be an initiator, a target, or both.  The iSCSI
   node's portals may be used to initiate connections (initiator) or
   listen for connections (target), depending on whether the iSCSI node
   is acting as an initiator or target.  The iSCSI MIB module assumes
   that any target may be accessed via any portal that can take on a
   target role, although other access controls not reflected in the
   module might limit this.

6.2.  iSCSI MIB Table Structure

   Each iSCSI object exports one or more tables: an attributes table,
   and zero or more statistics tables, which augment the attributes
   table.  Since iSCSI is an evolving standard, it is much cleaner to
   provide statistics and attributes as separate tables, allowing
   attributes and statistics to be added independently.  In a few cases,
   there are multiple categories of statistics that will likely grow; in
   this case, an object will contain multiple statistics tables.

   iscsiObjects
     iscsiDescriptors
     iscsiInstance
       iscsiInstanceAttributesTable
       iscsiInstanceSsnErrorStatsTable
         -- Counts abnormal session terminations
     iscsiPortal
       iscsiPortalAttributesTable
     iscsiTargetPortal
       iscsiTgtPortalAttributesTable
     iscsiInitiatorPortal
       iscsiIntrPortalAttributesTable
     iscsiNode
       iscsiNodeAttributesTable
     iscsiTarget
       iscsiTargetAttributesTable
       iscsiTargetLoginStatsTable
         -- Counts successful and unsuccessful logins
       iscsiTargetLogoutStatsTable
         -- Counts normal and abnormal logouts
     iscsiTgtAuthorization
       iscsiTgtAuthAttributesTable
     iscsiInitiator
       iscsiInitiatorAttributesTable
       iscsiInitiatorLoginStatsTable
         -- Counts successful and unsuccessful logins
       iscsiInitiatorLogoutStatsTable
         -- Counts normal and abnormal logouts
     iscsiIntrAuthorization
       iscsiIntrAuthAttributesTable



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     iscsiSession
       iscsiSessionAttributesTable
       iscsiSessionStatsTable
         -- Performance-related counts (requests, responses, bytes)
       iscsiSessionCxnErrorStatsTable
         -- Counts digest errors, connection errors, etc.
     iscsiConnection
       iscsiConnectionAttributesTable

   Note that this module does not attempt to count everything that could
   be counted; it is designed to include only those counters that would