Internet Draft Introduction to SNMPv2 November 1994
Introduction to Version 2 of the
Internet-standard Network Management Framework
1 November 1994
Jeffrey D. Case
SNMP Research, Inc.
case@snmp.com
Keith McCloghrie
Cisco Systems, Inc.
kzm@cisco.com
Marshall T. Rose
Dover Beach Consulting, Inc.
mrose@dbc.mtview.ca.us
Steven Waldbusser
Carnegie Mellon University
waldbusser@cmu.edu
<draft-ietf-snmpv2-intro-ds-00.txt>
Status of this Memo
This document is an Internet-Draft. 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.''
To learn the current status of any Internet-Draft, please check the
``1id-abstracts.txt'' listing contained in the Internet- Drafts Shadow
Directories on ds.internic.net (US East Coast), nic.nordu.net (Europe),
ftp.isi.edu (US West Coast), or munnari.oz.au (Pacific Rim).
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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].
1.1. Change Log
For the 1 November version:
- recast RFC 1441 into an Internet-Draft,
- fixed typos.
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2. Components of the SNMPv2 Framework
A 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 authentication,
authorization, access control, and privacy policies.
Management stations execute management applications which monitor and
control managed elements. Managed elements are devices such as hosts,
routers, terminal servers, etc., which are monitored and controlled via
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.
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.
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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:
(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
This document is a modified version of RFC 1441.
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", Internet Draft, SNMP
Research, Inc., Cisco Systems, Dover Beach Consulting, Inc.,
Carnegie Mellon University, November 1994.
[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)", Internet Draft, SNMP Research, Inc.,
Cisco Systems, Dover Beach Consulting, Inc., Carnegie Mellon
University, November 1994.
[7] Case, J., McCloghrie, K., Rose, M., and Waldbusser, S., "Textual
Conventions for Version 2 of the the Simple Network Management
Protocol (SNMPv2)", Internet Draft, SNMP Research, Inc., Cisco
Systems, Dover Beach Consulting, Inc., Carnegie Mellon University,
November 1994.
[8] Case, J., McCloghrie, K., Rose, M., and Waldbusser, S., "Protocol
Operations for Version 2 of the Simple Network Management Protocol
(SNMPv2)", Internet Draft, SNMP Research, Inc., Cisco Systems,
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Dover Beach Consulting, Inc., Carnegie Mellon University, November
1994.
[9] Case, J., McCloghrie, K., Rose, M., and Waldbusser, S., "Transport
Mappings for Version 2 of the Simple Network Management Protocol
(SNMPv2)", Internet Draft, SNMP Research, Inc., Cisco Systems,
Dover Beach Consulting, Inc., Carnegie Mellon University, November
1994.
[10] Case, J., McCloghrie, K., Rose, M., and Waldbusser, S., "Management
Information Base for Version 2 of the Simple Network Management
Protocol (SNMPv2)", Internet Draft, SNMP Research, Inc., Cisco
Systems, Dover Beach Consulting, Inc., Carnegie Mellon University,
November 1994.
[11] Case, J., McCloghrie, K., Rose, M., and Waldbusser, S., "Manager-
to-Manager Management Information Base", Internet Draft, SNMP
Research, Inc., Cisco Systems, Dover Beach Consulting, Inc.,
Carnegie Mellon University, November 1994.
[12] Galvin, J., and McCloghrie, K., "Administrative Model for Version 2
of the Simple Network Management Protocol (SNMPv2)", Internet
Draft, Trusted Information Systems, Cisco Systems, November 1994.
[13] Galvin, J., and McCloghrie, K., "Security Protocols for Version 2
of the Simple Network Management Protocol (SNMPv2)", Internet
Draft, Trusted Information Systems, Cisco Systems, November 1994.
[14] McCloghrie, K., and Galvin, J., "Party MIB for Version 2 of the
Simple Network Management Protocol (SNMPv2)", Internet Draft, Cisco
Systems, Trusted Information Systems, November 1994.
[15] Case, J., McCloghrie, K., Rose, M., and Waldbusser, S.,
"Conformance Statements for Version 2 of the the Simple Network
Management Protocol (SNMPv2)", Internet Draft, SNMP Research, Inc.,
Cisco Systems, Dover Beach Consulting, Inc., Carnegie Mellon
University, November 1994.
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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
Cisco Systems, Inc.
170 West Tasman Drive,
San Jose CA 95134-1706.
Phone: +1 408 526 5260
Email: kzm@cisco.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
5000 Forbes Ave
Pittsburgh, PA 15213
US
Phone: +1 412 268 6628
Email: waldbusser@cmu.edu
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Table of Contents
1 Introduction .................................................... 2
1.1 Change Log .................................................... 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 ................................................ 6
4 References ...................................................... 6
5 Security Considerations ......................................... 8
6 Authors' Addresses .............................................. 8
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