


          Network Working Group                                  J. Case
          Request for Comments: 1441                 SNMP Research, Inc.
                                                           K. McCloghrie
                                                      Hughes LAN Systems
                                                                 M. Rose
                                            Dover Beach Consulting, Inc.
                                                           S. Waldbusser
                                              Carnegie Mellon University
                                                              April 1993


                         Introduction to version 2 of the
                  Internet-standard Network Management Framework


          Status of this Memo

          This RFC specifes an IAB standards track protocol for the
          Internet community, and requests discussion and suggestions
          for improvements.  Please refer to the current edition of the
          "IAB Official Protocol Standards" for the standardization
          state and status of this protocol.  Distribution of this memo
          is unlimited.


          Table of Contents


          1 Introduction ..........................................    2
          2 Components of the SNMPv2 Framework ....................    3
          2.1 Structure of Management Information .................    3
          2.2 Textual Conventions .................................    4
          2.3 Protocol Operations .................................    4
          2.4 Transport Mappings ..................................    4
          2.5 Protocol Instrumentation ............................    5
          2.6 Administrative Framework ............................    5
          2.7 Conformance Statements ..............................    5
          3 Acknowledgements ......................................    7
          4 References ............................................   11
          5 Security Considerations ...............................   13
          6 Authors' Addresses ....................................   13













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          1.  Introduction

          The purpose of this document is to provide an overview of
          version 2 of the Internet-standard Network Management
          Framework, termed the SNMP version 2 framework (SNMPv2).  This
          framework is derived from the original Internet-standard
          Network Management Framework (SNMPv1), which consists of these
          three documents:

               RFC 1155 [1] which defines the Structure of Management
               Information (SMI), the mechanisms used for describing and
               naming objects for the purpose of management.

               RFC 1212 [2] which defines a more concise description
               mechanism, which is wholly consistent with the SMI.

               RFC 1157 [3] which defines the Simple Network Management
               Protocol (SNMP), the protocol used for network access to
               managed objects.

          For information on coexistence between SNMPv1 and SNMPv2,
          consult [4].




























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          2.  Components of the SNMPv2 Framework

          A network management system contains: several (potentially
          many) nodes, each with a processing entity, termed an agent,
          which has access to management instrumentation; at least one
          management station; and, a management protocol, used to convey
          management information between the agents and management
          stations.  Operations of the protocol are carried out under an
          administrative framework which defines both authentication and
          authorization policies.

          Network management stations execute management applications
          which monitor and control network elements.  Network elements
          are devices such as hosts, routers, terminal servers, etc.,
          which are monitored and controlled through access to their
          management information.


          2.1.  Structure of Management Information

          Management information is viewed as a collection of managed
          objects, residing in a virtual information store, termed the
          Management Information Base (MIB).  Collections of related
          objects are defined in MIB modules.  These modules are written
          using a subset of OSI's Abstract Syntax Notation One (ASN.1)
          [5].  It is the purpose of the Structure of Management
          Information for SNMPv2 document [6] to define that subset.

          The SMI is divided into three parts: module definitions,
          object definitions, and, trap definitions.

          (1)  Module definitions are used when describing information
               modules.  An ASN.1 macro, MODULE-IDENTITY, is used to
               concisely convey the semantics of an information module.

          (2)  Object definitions are used when describing managed
               objects.  An ASN.1 macro, OBJECT-TYPE, is used to
               concisely convey the syntax and semantics of a managed
               object.

          (3)  Notification definitions are used when describing
               unsolicited transmissions of management information.  An
               ASN.1 macro, NOTIFICATION-TYPE, is used to concisely
               convey the syntax and semantics of a notification.






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          2.2.  Textual Conventions

          When designing a MIB module, it is often useful to new define
          types similar to those defined in the SMI.  In comparison to a
          type defined in the SMI, each of these new types has a
          different name, a similar syntax, but a more precise
          semantics.  These newly defined types are termed textual
          conventions, and are used for the convenience of humans
          reading the MIB module.  It is the purpose of the Textual
          Conventions for SNMPv2 document [7] to define the initial set
          of textual conventions available to all MIB modules.

          Objects defined using a textual convention are always encoded
          by means of the rules that define their primitive type.
          However, textual conventions often have special semantics
          associated with them.  As such, an ASN.1 macro, TEXTUAL-
          CONVENTION, is used to concisely convey the syntax and
          semantics of a textual convention.


          2.3.  Protocol Operations

          The management protocol provides for the exchange of messages
          which convey management information between the agents and the
          management stations.  The form of these messages is a message
          "wrapper" which encapsulates a Protocol Data Unit (PDU).  The
          form and meaning of the "wrapper" is determined by an
          administrative framework which defines both authentication and
          authorization policies.

          It is the purpose of the Protocol Operations for SNMPv2
          document [8] to define the operations of the protocol with
          respect to the sending and receiving of the PDUs.


          2.4.  Transport Mappings

          The management protocol, version 2 of the Simple Network
          Management Protocol, may be used over a variety of protocol
          suites.  It is the purpose of the Transport Mappings for
          SNMPv2 document [9] to define how the SNMPv2 maps onto an
          initial set of transport domains.  Other mappings may be
          defined in the future.







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          Although several mappings are defined, the mapping onto UDP is
          the preferred mapping.  As such, to provide for the greatest
          level of interoperability, systems which choose to deploy
          other mappings should also provide for proxy service to the
          UDP mapping.


          2.5.  Protocol Instrumentation

          It is the purpose of the Management Information Base for
          SNMPv2 document [10] to define managed objects which describe
          the behavior of a SNMPv2 entity.  The Manager-to-Manager MIB
          document [11] defines an initial set of managed objects which
          describe the behavior of a SNMPv2 entity which acts in a
          manager role.  It is expected that extensions to this MIB will
          be defined in the future.


          2.6.  Administrative Framework

          It is the purpose of the Administrative Model for SNMPv2
          document [12] to define the behavior of a SNMPv2 party - a
          conceptual, virtual execution context whose operation is
          restricted (for security or other purposes) to an
          administratively defined subset of all possible operations of
          a particular SNMPv2 entity.

          Associated with each SNMPv2 party is a single authentication
          protocol and a single privacy protocol.  It is the purpose of
          the Security Protocols for SNMPv2 document [13] to define
          those protocols.

          The Party MIB for SNMPv2 document [14] defines managed objects
          which correspond to the properties associated with a SNMPv2
          party.


          2.7.  Conformance Statements

          It may be useful to define the acceptable lower-bounds of
          implementation, along with the actual level of implementation
          achieved.  It is the purpose of the Conformance Statements for
          SNMPv2 document [15] to define the notation used for these
          purposes.  There are two kinds of notations:






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          (1)  Compliance statements are used when describing
               requirements for agents with respect to object
               definitions.  An ASN.1 macro, MODULE-COMPLIANCE, is used
               to concisely convey such requirements.

          (2)  Capability statements are used when describing
               capabilities of agents with respect to object
               definitions.  An ASN.1 macro, AGENT-CAPABILITIES, is used
               to concisely convey such capabilities.

          Finally, collections of related objects are grouped together
          to form a unit of conformance.  An ASN.1 macro, OBJECT-GROUP,
          is used to concisely convey the syntax and semantics of a
          group.




































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          3.  Acknowledgements

          The SNMPv2 framework is based on the outstanding technical
          direction pioneered by the original authors of the SGMP: James
          R. (Chuck) Davin, of the MIT Laboratory for Computer Science,
          Mark S. Fedor, of Performance Systems International, Inc.,
          Martin L. Schoffstall, also of PSI, and Jeffrey D. Case.

          Since the invention of the SGMP in 1987, many individuals have
          devoted much energy toward creating the unprecedented success
          of the Internet-standard Network Management Framework.  As
          such, the list of people worthy of acknowledgement is too
          great to enumerate here.

          However, in retrospect, it seems clear that the concepts in
          the original architecture, as envisioned by Chuck Davin, have
          provided the basis for the success of the current framework.
          We hope that the SNMPv2 framework will be able to successfully
          build on this work.

          Finally, the comments of the SNMP version 2 working group are
          gratefully acknowledged:

               Beth Adams, Network Management Forum
               Steve Alexander, INTERACTIVE Systems Corporation
               David Arneson, Cabletron Systems
               Toshiya Asaba
               Fred Baker, ACC
               Jim Barnes, Xylogics, Inc.
               Brian Bataille
               Andy Bierman, SynOptics Communications, Inc.
               Uri Blumenthal, IBM Corporation
               Fred Bohle, Interlink
               Jack Brown
               Theodore Brunner, Bellcore
               Stephen F. Bush, GE Information Services
               Jeffrey D. Case, University of Tennessee, Knoxville
               John Chang, IBM Corporation
               Szusin Chen, Sun Microsystems
               Robert Ching
               Chris Chiotasso, Ungermann-Bass
               Bobby A. Clay, NASA/Boeing
               John Cooke, Chipcom
               Tracy Cox, Bellcore
               Juan Cruz, Datability, Inc.





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               David Cullerot, Cabletron Systems
               Cathy Cunningham, Microcom
               James R. (Chuck) Davin, Bellcore
               Michael Davis, Clearpoint
               Mike Davison, FiberCom
               Cynthia DellaTorre, MITRE
               Taso N. Devetzis, Bellcore
               Manual Diaz, DAVID Systems, Inc.
               Jon Dreyer, Sun Microsystems
               David Engel, Optical Data Systems
               Mike Erlinger, Lexcel
               Roger Fajman, NIH
               Daniel Fauvarque, Sun Microsystems
               Karen Frisa, CMU
               Shari Galitzer, MITRE
               Shawn Gallagher, Digital Equipment Corporation
               Richard Graveman, Bellcore
               Maria Greene, Xyplex, Inc.
               Michel Guittet, Apple
               Robert Gutierrez, NASA
               Bill Hagerty, Cabletron Systems
               Gary W. Haney, Martin Marietta Energy Systems
               Patrick Hanil, Nokia Telecommunications
               Matt Hecht, SNMP Research, Inc.
               Edward A. Heiner, Jr., Synernetics Inc.
               Susan E. Hicks, Martin Marietta Energy Systems
               Geral Holzhauer, Apple
               John Hopprich, DAVID Systems, Inc.
               Jeff Hughes, Hewlett-Packard
               Robin Iddon, Axon Networks, Inc.
               David Itusak
               Kevin M. Jackson, Concord Communications, Inc.
               Ole J. Jacobsen, Interop Company
               Ronald Jacoby, Silicon Graphics, Inc.
               Satish Joshi, SynOptics Communications, Inc.
               Frank Kastenholz, FTP Software
               Mark Kepke, Hewlett-Packard
               Ken Key, SNMP Research, Inc.
               Zbiginew Kielczewski, Eicon
               Jongyeoi Kim
               Andrew Knutsen, The Santa Cruz Operation
               Michael L. Kornegay, VisiSoft
               Deirdre C. Kostik, Bellcore
               Cheryl Krupczak, Georgia Tech
               Mark S. Lewis, Telebit





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               David Lin
               David Lindemulder, AT&T/NCR
               Ben Lisowski, Sprint
               David Liu, Bell-Northern Research
               John Lunny, The Wollongong Group
               Robert C. Lushbaugh Martin, Marietta Energy Systems
               Michael Luufer, BBN
               Carl Madison, Star-Tek, Inc.
               Keith McCloghrie, Hughes LAN Systems
               Evan McGinnis, 3Com Corporation
               Bill McKenzie, IBM Corporation
               Donna McMaster, SynOptics Communications, Inc.
               John Medicke, IBM Corporation
               Doug Miller, Telebit
               Dave Minnich, FiberCom
               Mohammad Mirhakkak, MITRE
               Rohit Mital, Protools
               George Mouradian, AT&T Bell Labs
               Patrick Mullaney, Cabletron Systems
               Dan Myers, 3Com Corporation
               Rina Nathaniel, Rad Network Devices Ltd.
               Hien V. Nguyen, Sprint
               Mo Nikain
               Tom Nisbet
               William B. Norton, MERIT
               Steve Onishi, Wellfleet Communications, Inc.
               David T. Perkins, SynOptics Communications, Inc.
               Carl Powell, BBN
               Ilan Raab, SynOptics Communications, Inc.
               Richard Ramons, AT&T
               Venkat D. Rangan, Metric Network Systems, Inc.
               Louise Reingold, Sprint
               Sam Roberts, Farallon Computing, Inc.
               Kary Robertson, Concord Communications, Inc.
               Dan Romascanu, Lannet Data Communications Ltd.
               Marshall T. Rose, Dover Beach Consulting, Inc.
               Shawn A. Routhier, Epilogue Technology Corporation
               Chris Rozman
               Asaf Rubissa, Fibronics
               Jon Saperia, Digital Equipment Corporation
               Michael Sapich
               Mike Scanlon, Interlan
               Sam Schaen, MITRE
               John Seligson, Ultra Network Technologies
               Paul A. Serice, Corporation for Open Systems





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               Chris Shaw, Banyan Systems
               Timon Sloane
               Robert Snyder, Cisco Systems
               Joo Young Song
               Roy Spitier, Sprint
               Einar Stefferud, Network Management Associates
               John Stephens, Cayman Systems, Inc.
               Robert L. Stewart, Xyplex, Inc. (chair)
               Kaj Tesink, Bellcore
               Dean Throop, Data General
               Ahmet Tuncay, France Telecom-CNET
               Maurice Turcotte, Racal Datacom
               Warren Vik, INTERACTIVE Systems Corporation
               Yannis Viniotis
               Steven L. Waldbusser, Carnegie Mellon Universitty
               Timothy M. Walden, ACC
               Alice Wang, Sun Microsystems
               James Watt, Newbridge
               Luanne Waul, Timeplex
               Donald E. Westlake III, Digital Equipment Corporation
               Gerry White
               Bert Wijnen, IBM Corporation
               Peter Wilson, 3Com Corporation
               Steven Wong, Digital Equipment Corporation
               Randy Worzella, IBM Corporation
               Daniel Woycke, MITRE
               Honda Wu
               Jeff Yarnell, Protools
               Chris Young, Cabletron
               Kiho Yum, 3Com Corporation




















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          4.  References

          [1]  Rose, M., and McCloghrie, K., "Structure and
               Identification of Management Information for TCP/IP-based
               internets", STD 16, RFC 1155, May 1990.

          [2]  Rose, M., and McCloghrie, K., "Concise MIB Definitions",
               STD 16, RFC 1212, March 1991.

          [3]  Case, J., Fedor, M., Schoffstall, M., Davin, J., "Simple
               Network Management Protocol", STD 15, RFC 1157, SNMP
               Research, Performance Systems International, MIT
               Laboratory for Computer Science, May 1990.

          [4]  Case, J., McCloghrie, K., Rose, M., and Waldbusser, S.,
               "Coexistence between version 1 and version 2 of the
               Internet-standard Network Management Framework", RFC
               1452, SNMP Research, Inc., Hughes LAN Systems, Dover
               Beach Consulting, Inc., Carnegie Mellon University, April
               1993.

          [5]  Information processing systems - Open Systems
               Interconnection - Specification of Abstract Syntax
               Notation One (ASN.1), International Organization for
               Standardization.  International Standard 8824, (December,
               1987).

          [6]  Case, J., McCloghrie, K., Rose, M., and Waldbusser, S.,
               "Structure of Management Information for version 2 of the
               Simple Network Management Protocol (SNMPv2)", RFC 1442,
               SNMP Research, Inc., Hughes LAN Systems, Dover Beach
               Consulting, Inc., Carnegie Mellon University, April 1993.

          [7]  Case, J., McCloghrie, K., Rose, M., and Waldbusser, S.,
               "Textual Conventions for version 2 of the the Simple
               Network Management Protocol (SNMPv2)", RFC 1443, SNMP
               Research, Inc., Hughes LAN Systems, Dover Beach
               Consulting, Inc., Carnegie Mellon University, April 1993.

          [8]  Case, J., McCloghrie, K., Rose, M., and Waldbusser, S.,
               "Protocol Operations for version 2 of the Simple Network
               Management Protocol (SNMPv2)", RFC 1448, SNMP Research,
               Inc., Hughes LAN Systems, Dover Beach Consulting, Inc.,
               Carnegie Mellon University, April 1993.






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          [9]  Case, J., McCloghrie, K., Rose, M., and Waldbusser, S.,
               "Transport Mappings for version 2 of the Simple Network
               Management Protocol (SNMPv2)", RFC 1449, SNMP Research,
               Inc., Hughes LAN Systems, Dover Beach Consulting, Inc.,
               Carnegie Mellon University, April 1993.

          [10] Case, J., McCloghrie, K., Rose, M., and Waldbusser, S.,
               "Management Information Base for version 2 of the Simple
               Network Management Protocol (SNMPv2)", RFC 1450, SNMP
               Research, Inc., Hughes LAN Systems, Dover Beach
               Consulting, Inc., Carnegie Mellon University, April 1993.

          [11] Case, J., McCloghrie, K., Rose, M., and Waldbusser, S.,
               "Manager-to-Manager Management Information Base", RFC
               1451, SNMP Research, Inc., Hughes LAN Systems, Dover
               Beach Consulting, Inc., Carnegie Mellon University, April
               1993.

          [12] Galvin, J., and McCloghrie, K., "Administrative Model for
               version 2 of the Simple Network Management Protocol
               (SNMPv2)", RFC 1445, Trusted Information Systems, Hughes
               LAN Systems, April 1993.

          [13] Galvin, J., and McCloghrie, K., "Security Protocols for
               version 2 of the Simple Network Management Protocol
               (SNMPv2)", RFC 1446, Trusted Information Systems, Hughes
               LAN Systems, April 1993.

          [14] McCloghrie, K., and Galvin, J., "Party MIB for version 2
               of the Simple Network Management Protocol (SNMPv2)", RFC
               1447, Hughes LAN Systems, Trusted Information Systems,
               April 1993.

          [15] Case, J., McCloghrie, K., Rose, M., and Waldbusser, S.,
               "Conformance Statements for version 2 of the the Simple
               Network Management Protocol (SNMPv2)", RFC 1444, SNMP
               Research, Inc., Hughes LAN Systems, Dover Beach
               Consulting, Inc., Carnegie Mellon University, April 1993.












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          5.  Security Considerations

          Security issues are not discussed in this memo.


          6.  Authors' Addresses

               Jeffrey D. Case
               SNMP Research, Inc.
               3001 Kimberlin Heights Rd.
               Knoxville, TN  37920-9716
               US

               Phone: +1 615 573 1434
               Email: case@snmp.com


               Keith McCloghrie
               Hughes LAN Systems
               1225 Charleston Road
               Mountain View, CA  94043
               US

               Phone: +1 415 966 7934
               Email: kzm@hls.com


               Marshall T. Rose
               Dover Beach Consulting, Inc.
               420 Whisman Court
               Mountain View, CA  94043-2186
               US

               Phone: +1 415 968 1052
               Email: mrose@dbc.mtview.ca.us

               Steven Waldbusser
               Carnegie Mellon University
               4910 Forbes Ave
               Pittsburgh, PA  15213
               US

               Phone: +1 412 268 6628
               Email: waldbusser@cmu.edu






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