draft-ietf-snmpv3-next-gen-arch-05.txt   draft-ietf-snmpv3-next-gen-arch-06.txt 
INTERNET-DRAFT D. Harrington INTERNET-DRAFT D. Harrington
Cabletron Systems, Inc. Cabletron Systems, Inc.
R. Presuhn R. Presuhn
BMC Software, Inc. BMC Software, Inc.
B. Wijnen B. Wijnen
IBM T. J. Watson Research IBM T. J. Watson Research
30 September 1997 28 October 1997
An Architecture for Describing An Architecture for Describing
SNMP Management Frameworks SNMP Management Frameworks
<draft-ietf-snmpv3-next-gen-arch-05.txt> <draft-ietf-snmpv3-next-gen-arch-06.txt>
Status of this Memo Status of this Memo
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Copyright Notice
Copyright (C) The Internet Society (1997). All Rights Reserved.
Abstract Abstract
This document describes an architecture for describing SNMP This document describes an architecture for describing SNMP
Management Frameworks. The architecture is designed to be modular to Management Frameworks. The architecture is designed to be modular to
allow the evolution of the SNMP protocol standards over time. The allow the evolution of the SNMP protocol standards over time. The
major portions of the architecture are an SNMP engine containing a major portions of the architecture are an SNMP engine containing a
Message Processing Subsystem, a Security Subsystem and an Access Message Processing Subsystem, a Security Subsystem and an Access
Control Subsystem, and possibly multiple SNMP applications which Control Subsystem, and possibly multiple SNMP applications which
provide specific functional processing of management data. provide specific functional processing of management data.
Table of Contents
1. Introduction ................................................ 5
1.1. Overview .................................................. 5
1.2. SNMP ...................................................... 5
1.3. Goals of this Architecture ................................ 6
1.4. Security Requirements of this Architecture ................ 7
1.5. Design Decisions .......................................... 8
2. Documentation Overview ...................................... 9
2.1. Document Roadmap .......................................... 11
2.2. Applicability Statement ................................... 11
2.3. Coexistence and Transition ................................ 11
2.4. Transport Mappings ........................................ 11
2.5. Message Processing ........................................ 12
2.6. Security .................................................. 12
2.7. Access Control ............................................ 12
2.8. Protocol Operations ....................................... 13
2.9. Applications .............................................. 13
2.10. Structure of Management Information ...................... 13
2.11. Textual Conventions ...................................... 13
2.12. Conformance Statements ................................... 14
2.13. Management Information Base Modules ...................... 14
2.13.1. SNMP Instrumentation MIBs .............................. 14
2.14. SNMP Framework Documents ................................. 14
3. Elements of the Architecture ................................ 15
3.1. The Naming of Entities .................................... 15
3.1.1. SNMP engine ............................................. 16
3.1.1.1. snmpEngineID .......................................... 17
3.1.1.2. Dispatcher ............................................ 17
3.1.1.3. Message Processing Subsystem .......................... 18
3.1.1.3.1. Message Processing Model ............................ 18
3.1.1.4. Security Subsystem .................................... 19
3.1.1.4.1. Security Model ...................................... 19
3.1.1.4.2. Security Protocol ................................... 19
3.1.2. Access Control Subsystem ................................ 20
3.1.2.1. Access Control Model .................................. 20
3.1.3. Applications ............................................ 20
3.1.3.1. SNMP Manager .......................................... 21
3.1.3.2. SNMP Agent ............................................ 22
3.2. The Naming of Identities .................................. 23
3.2.1. Principal ............................................... 23
3.2.2. securityName ............................................ 23
3.2.3. Model-dependent security ID ............................. 24
3.3. The Naming of Management Information ...................... 25
3.3.1. An SNMP Context ......................................... 26
3.3.2. contextEngineID ......................................... 26
3.3.3. contextName ............................................. 27
3.3.4. scopedPDU ............................................... 27
3.4. Other Constructs .......................................... 27
3.4.1. maxSizeResponseScopedPDU ................................ 27
3.4.2. Local Configuration Datastore ........................... 27
3.4.3. securityLevel ........................................... 27
4. Abstract Service Interfaces ................................. 28
4.1. Dispatcher Primitives ..................................... 28
4.1.1. Generate Outgoing Request or Notification ............... 28
4.1.2. Process Incoming Request or Notification PDU ............ 28
4.1.3. Generate Outgoing Response .............................. 30
4.1.4. Process Incoming Response PDU ........................... 30
4.1.5. Registering Responsibility for Handling SNMP PDUs ....... 30
4.2. Message Processing Subsystem Primitives ................... 31
4.2.1. Prepare Outgoing SNMP Request or Notification Message ... 31
4.2.2. Prepare an Outgoing SNMP Response Message ............... 32
4.2.3. Prepare Data Elements from an Incoming SNMP Message ..... 33
4.3. Access Control Subsystem Primitives ....................... 33
4.4. Security Subsystem Primitives ............................. 34
4.4.1. Generate a Request or Notification Message .............. 34
4.4.2. Process Incoming Message ................................ 34
4.4.3. Generate a Response Message ............................. 35
4.5. Common Primitives ......................................... 35
4.5.1. Release State Reference Information ..................... 35
4.6. Scenario Diagrams ......................................... 36
4.6.1. Command Generator or Notification Originator ............ 36
4.6.2. Scenario Diagram for a Command Responder Application .... 37
5. Managed Object Definitions for SNMP Management Frameworks ... 38
6. Intellectual Property ....................................... 47
7. Acknowledgements ............................................ 48
8. Security Considerations ..................................... 49
9. References .................................................. 50
10. Editor's Addresses ......................................... 52
A. Guidelines for Model Designers .............................. 53
A.1. Security Model Design Requirements ........................ 53
A.1.1. Threats ................................................. 53
A.1.2. Security Processing ..................................... 54
A.1.3. Validate the security-stamp in a received message ....... 54
A.1.4. Security MIBs ........................................... 55
A.1.5. Cached Security Data .................................... 55
A.2. Message Processing Model Design Requirements .............. 55
A.2.1. Receiving an SNMP Message from the Network .............. 56
A.2.2. Sending an SNMP Message to the Network .................. 56
A.3. Application Design Requirements ........................... 56
A.3.1. Applications that Initiate Messages ..................... 57
A.3.2. Applications that Receive Responses ..................... 57
A.3.3. Applications that Receive Asynchronous Messages ......... 57
A.3.4. Applications that Send Responses ........................ 58
A.4. Access Control Model Design Requirements .................. 58
B. Issues ...................................................... 59
B.1. Open Issues ............................................... 59
B.2. Change Log ................................................ 59
C. Full Copyright Statement .................................... 59
1. Introduction 1. Introduction
1.1. Overview 1.1. Overview
This document defines a vocabulary for describing SNMP Management This document defines a vocabulary for describing SNMP Management
Frameworks, and an architecture for describing the major portions of Frameworks, and an architecture for describing the major portions of
SNMP Management Frameworks. SNMP Management Frameworks.
This document does not provide a general introduction to SNMP. Other This document does not provide a general introduction to SNMP. Other
documents and books can provide a much better introduction to SNMP. documents and books can provide a much better introduction to SNMP.
skipping to change at page 1, line 116 skipping to change at page 6, line 29
It is the purpose of this document to define an architecture which It is the purpose of this document to define an architecture which
can evolve to realize effective management in a variety of can evolve to realize effective management in a variety of
configurations and environments. The architecture has been designed configurations and environments. The architecture has been designed
to meet the needs of implementations of: to meet the needs of implementations of:
- minimal SNMP entities with command responder and/or - minimal SNMP entities with command responder and/or
notification originator applications (traditionally called SNMP notification originator applications (traditionally called SNMP
agents), agents),
- SNMP entities with proxy forwarder applications (traditionally - SNMP entities with proxy forwarder applications (traditionally
called SNMP proxy agent), called SNMP proxy agents),
- command line driven SNMP entities with command generator and/or - command line driven SNMP entities with command generator and/or
notification receiver applications (traditionally called SNMP notification receiver applications (traditionally called SNMP
command line managers), command line managers),
- SNMP entities with command generator and/or notification - SNMP entities with command generator and/or notification
receiver, plus command responder and/or notification originator receiver, plus command responder and/or notification originator
applications (traditionally called SNMP mid-level managers or applications (traditionally called SNMP mid-level managers or
dual-role entities), dual-role entities),
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2) the naming of identities, and 2) the naming of identities, and
3) the naming of management information. 3) the naming of management information.
This architecture also defines some names for other constructs that This architecture also defines some names for other constructs that
are used in the documentation. are used in the documentation.
3.1. The Naming of Entities 3.1. The Naming of Entities
The following figure shows detail about an SNMP entity and how An SNMP entity is an implementation of this architecture. Each such
components within it are named. SNMP entity consists of an SNMP engine and one or more associated
applications.
The following figure shows details about an SNMP entity and the
components within it.
+-------------------------------------------------------------------+ +-------------------------------------------------------------------+
| SNMP entity | | SNMP entity |
| | | |
| +-------------------------------------------------------------+ | | +-------------------------------------------------------------+ |
| | SNMP engine (identified by snmpEngineID) | | | | SNMP engine (identified by snmpEngineID) | |
| | | | | | | |
| | +------------+ +------------+ +-----------+ +-----------+ | | | | +------------+ +------------+ +-----------+ +-----------+ | |
| | | | | | | | | | | | | | | | | | | | | | | |
| | | Dispatcher | | Message | | Security | | Access | | | | | | Dispatcher | | Message | | Security | | Access | | |
skipping to change at page 1, line 581 skipping to change at page 16, line 38
| | | | | | | |
| | +-------------+ +--------------+ +--------------+ | | | | +-------------+ +--------------+ +--------------+ | |
| | | Command | | Notification | | Other | | | | | | Command | | Notification | | Other | | |
| | | Responder | | Originator | | | | | | | | Responder | | Originator | | | | |
| | +-------------+ +--------------+ +--------------+ | | | | +-------------+ +--------------+ +--------------+ | |
| | | | | | | |
| +-------------------------------------------------------------+ | | +-------------------------------------------------------------+ |
| | | |
+-------------------------------------------------------------------+ +-------------------------------------------------------------------+
3.1.1. SNMP entity 3.1.1. SNMP engine
An SNMP entity is an implementation of this architecture. Each such
SNMP entity consists of an SNMP engine and one or more associated
applications.
3.1.2. SNMP engine
An SNMP engine provides services for sending and receiving messages, An SNMP engine provides services for sending and receiving messages,
authenticating and encrypting messages, and controlling access to authenticating and encrypting messages, and controlling access to
managed objects. There is a one-to-one association between an SNMP managed objects. There is a one-to-one association between an SNMP
engine and the SNMP entity which contains it. engine and the SNMP entity which contains it.
The engine contains: The engine contains:
1) a Dispatcher, 1) a Dispatcher,
skipping to change at page 1, line 601 skipping to change at page 17, line 4
managed objects. There is a one-to-one association between an SNMP managed objects. There is a one-to-one association between an SNMP
engine and the SNMP entity which contains it. engine and the SNMP entity which contains it.
The engine contains: The engine contains:
1) a Dispatcher, 1) a Dispatcher,
2) a Message Processing Subsystem, 2) a Message Processing Subsystem,
3) a Security Subsystem, and 3) a Security Subsystem, and
4) an Access Control Subsystem. 4) an Access Control Subsystem.
3.1.3. snmpEngineID 3.1.1.1. snmpEngineID
Within an administrative domain, an snmpEngineID is the unique and Within an administrative domain, an snmpEngineID is the unique and
unambiguous identifier of an SNMP engine. Since there is a one-to-one unambiguous identifier of an SNMP engine. Since there is a one-to-one
association between SNMP engines and SNMP entities, it also uniquely association between SNMP engines and SNMP entities, it also uniquely
and unambiguously identifies the SNMP entity. and unambiguously identifies the SNMP entity.
3.1.4. Dispatcher 3.1.1.2. Dispatcher
There is only one Dispatcher in an SNMP engine. It allows for There is only one Dispatcher in an SNMP engine. It allows for
concurrent support of multiple versions of SNMP messages in the SNMP concurrent support of multiple versions of SNMP messages in the SNMP
engine. It does so by: engine. It does so by:
- sending and receiving SNMP messages to/from the network, - sending and receiving SNMP messages to/from the network,
- determining the version of an SNMP message and interact with - determining the version of an SNMP message and interacting with
the corresponding Message Processing Model, the corresponding Message Processing Model,
- providing an abstract interface to SNMP applications for - providing an abstract interface to SNMP applications for
delivery of a PDU to an application. delivery of a PDU to an application.
- providing an abstract interface for SNMP applications that - providing an abstract interface for SNMP applications that
allows them to send a PDU to a remote SNMP entity. allows them to send a PDU to a remote SNMP entity.
3.1.5. Message Processing Subsystem 3.1.1.3. Message Processing Subsystem
The Message Processing Subsystem is responsible for preparing The Message Processing Subsystem is responsible for preparing
messages for sending, and extracting data from received messages. messages for sending, and extracting data from received messages.
The Message Processing Subsystem potentially contains multiple The Message Processing Subsystem potentially contains multiple
Message Processing Models as shown in the next figure. Message Processing Models as shown in the next figure.
* One or more Message Processing Models may be present. * One or more Message Processing Models may be present.
+------------------------------------------------------------------+ +------------------------------------------------------------------+
skipping to change at page 1, line 653 skipping to change at page 18, line 30
| | * | | * | | * | | * | | | | * | | * | | * | | * | |
| | SNMPv3 | | SNMPv1 | | SNMPv2c | | Other | | | | SNMPv3 | | SNMPv1 | | SNMPv2c | | Other | |
| | Message | | Message | | Message | | Message | | | | Message | | Message | | Message | | Message | |
| | Processing | | Processing | | Processing | | Processing | | | | Processing | | Processing | | Processing | | Processing | |
| | Model | | Model | | Model | | Model | | | | Model | | Model | | Model | | Model | |
| | | | | | | | | | | | | | | | | | | |
| +------------+ +------------+ +------------+ +------------+ | | +------------+ +------------+ +------------+ +------------+ |
| | | |
+------------------------------------------------------------------+ +------------------------------------------------------------------+
3.1.6. Message Processing Model 3.1.1.3.1. Message Processing Model
Each Message Processing Model defines the format of a particular Each Message Processing Model defines the format of a particular
version of an SNMP message and coordinates the preparation and version of an SNMP message and coordinates the preparation and
extraction of each such version-specific messages. extraction of each such version-specific message format.
3.1.7. Security Subsystem 3.1.1.4. Security Subsystem
The Security Subsystem provides security services such as the The Security Subsystem provides security services such as the
authentication and privacy of messages and potentially contains authentication and privacy of messages and potentially contains
multiple Security Models as shown in the following figure multiple Security Models as shown in the following figure
* One or more Security Models may be present. * One or more Security Models may be present.
+------------------------------------------------------------------+ +------------------------------------------------------------------+
| | | |
| Security Subsystem | | Security Subsystem |
skipping to change at page 1, line 681 skipping to change at page 19, line 27
| +----------------+ +-----------------+ +-------------------+ | | +----------------+ +-----------------+ +-------------------+ |
| | * | | * | | * | | | | * | | * | | * | |
| | User-Based | | Other | | Other | | | | User-Based | | Other | | Other | |
| | Security | | Security | | Security | | | | Security | | Security | | Security | |
| | Model | | Model | | Model | | | | Model | | Model | | Model | |
| | | | | | | | | | | | | | | |
| +----------------+ +-----------------+ +-------------------+ | | +----------------+ +-----------------+ +-------------------+ |
| | | |
+------------------------------------------------------------------+ +------------------------------------------------------------------+
3.1.8. Security Model 3.1.1.4.1. Security Model
A Security Model defines the threats against which it protects, the A Security Model defines the threats against which it protects, the
goals of its services, and the security protocols used to provide goals of its services, and the security protocols used to provide
security services such as authentication and privacy. security services such as authentication and privacy.
3.1.9. Security Protocol 3.1.1.4.2. Security Protocol
A Security Protocol defines the mechanisms, procedures, and MIB data A Security Protocol defines the mechanisms, procedures, and MIB data
used to provide a security service such as authentication or privacy. used to provide a security service such as authentication or privacy.
3.1.10. Access Control Subsystem 3.1.2. Access Control Subsystem
The Access Control Subsystem provides authorization services by means The Access Control Subsystem provides authorization services by means
of one or more Access Control Models. of one or more Access Control Models.
+------------------------------------------------------------------+ +------------------------------------------------------------------+
| | | |
| Access Control Subsystem | | Access Control Subsystem |
| | | |
| +---------------+ +-----------------+ +------------------+ | | +---------------+ +-----------------+ +------------------+ |
| | * | | * | | * | | | | * | | * | | * | |
| | View-Based | | Other | | Other | | | | View-Based | | Other | | Other | |
| | Access | | Access | | Access | | | | Access | | Access | | Access | |
| | Control | | Control | | Control | | | | Control | | Control | | Control | |
| | Model | | Model | | Model | | | | Model | | Model | | Model | |
| | | | | | | | | | | | | | | |
| +---------------+ +-----------------+ +------------------+ | | +---------------+ +-----------------+ +------------------+ |
| | | |
+------------------------------------------------------------------+ +------------------------------------------------------------------+
3.1.11. Access Control Model 3.1.2.1. Access Control Model
An Access Control Model defines a particular access decision function An Access Control Model defines a particular access decision function
in order to support decisions regarding access rights. in order to support decisions regarding access rights.
3.1.12. Applications 3.1.3. Applications
There are several types of applications, including: There are several types of applications, including:
- command generators, which monitor and manipulate management - command generators, which monitor and manipulate management
data, data,
- command responders, which provide access to management data, - command responders, which provide access to management data,
- notification originators, which initiate asynchronous messages, - notification originators, which initiate asynchronous messages,
- notification receivers, which process asynchronous messages, - notification receivers, which process asynchronous messages,
and and
- proxy forwarders, which forward messages between entities. - proxy forwarders, which forward messages between entities.
These applications make use of the services provided by the SNMP These applications make use of the services provided by the SNMP
engine. engine.
3.1.13. SNMP Manager 3.1.3.1. SNMP Manager
An SNMP entity containing one or more command generator and/or An SNMP entity containing one or more command generator and/or
notification receiver applications (along with their associated SNMP notification receiver applications (along with their associated SNMP
engine) has traditionally been called an SNMP manager. engine) has traditionally been called an SNMP manager.
* One or more models may be present. * One or more models may be present.
(traditional SNMP manager) (traditional SNMP manager)
+-------------------------------------------------------------------+ +-------------------------------------------------------------------+
| +--------------+ +--------------+ +--------------+ SNMP entity | | +--------------+ +--------------+ +--------------+ SNMP entity |
| | NOTIFICATION | | NOTIFICATION | | COMMAND | | | | NOTIFICATION | | NOTIFICATION | | COMMAND | |
skipping to change at page 1, line 785 skipping to change at page 22, line 5
+-----+ +-----+ +-------+ +-----+ +-----+ +-------+
| UDP | | IPX | . . . | other | | UDP | | IPX | . . . | other |
+-----+ +-----+ +-------+ +-----+ +-----+ +-------+
^ ^ ^ ^ ^ ^
| | | | | |
v v v v v v
+------------------------------+ +------------------------------+
| Network | | Network |
+------------------------------+ +------------------------------+
3.1.14. SNMP Agent 3.1.3.2. SNMP Agent
An SNMP entity containing one or more command responder and/or An SNMP entity containing one or more command responder and/or
notification originator applications (along with their associated notification originator applications (along with their associated
SNMP engine) has traditionally been called an SNMP agent. SNMP engine) has traditionally been called an SNMP agent.
+------------------------------+ +------------------------------+
| Network | | Network |
+------------------------------+ +------------------------------+
^ ^ ^ ^ ^ ^
| | | | | |
v v v v v v
skipping to change at page 1, line 865 skipping to change at page 23, line 36
| | | | | | | | | | | |
| | +------------------------------+ | | | | +------------------------------+ | |
| | ^ | | | | ^ | |
| | | | | | | | | |
| +-------------------------|----------+ | | +-------------------------|----------+ |
| | | | | |
| | | | | |
+----------------------------|-------------+ +----------------------------|-------------+
| |
v v
wire network
3.2.1. Principal 3.2.1. Principal
A principal is the "who" on whose behalf services are provided or A principal is the "who" on whose behalf services are provided or
processing takes place. processing takes place.
A principal can be, among other things, an individual acting in a A principal can be, among other things, an individual acting in a
particular role; a set of individuals, with each acting in a particular role; a set of individuals, with each acting in a
particular role; an application or a set of applications; and particular role; an application or a set of applications; and
combinations thereof. combinations thereof.
3.2.2. securityName 3.2.2. securityName
A securityName is a human readable string representing a principal. A securityName is a human readable string representing a principal.
It has a model-independent It has a model-independent format, and can be used outside a
format, and can be used outside a particular Security Model. particular Security Model.
3.2.3. Model-dependent security ID 3.2.3. Model-dependent security ID
A model-dependent security ID is the model-specific representation of A model-dependent security ID is the model-specific representation of
a securityName within a particular Security Model. a securityName within a particular Security Model.
Model-dependent security IDs may or may not be human readable, and Model-dependent security IDs may or may not be human readable, and
have a model-dependent syntax. Examples include community names, user have a model-dependent syntax. Examples include community names, user
names, and parties. names, and parties.
The transformation of model-dependent security IDs into securityNames The transformation of model-dependent security IDs into securityNames
and vice versa is the responsibility of the relevant Security Model. and vice versa is the responsibility of the relevant Security Model.
3.3. The Naming of Management Information 3.3. The Naming of Management Information
Management information resides at an SNMP entity where a Command Management information resides at an SNMP entity where a Command
Responder Application has local access to potentially multiple Responder Application has local access to potentially multiple
contexts. Such a Command Responder application uses a contextEngineID contexts. This application uses a contextEngineID equal to the
equal to the snmpEngineID of its associated SNMP engine. snmpEngineID of its associated SNMP engine.
+-----------------------------------------------------------------+ +-----------------------------------------------------------------+
| SNMP entity (identified by snmpEngineID, example: abcd) | | SNMP entity (identified by snmpEngineID, example: abcd) |
| | | |
| +------------------------------------------------------------+ | | +------------------------------------------------------------+ |
| | SNMP engine (identified by snmpEngineID) | | | | SNMP engine (identified by snmpEngineID) | |
| | | | | | | |
| | +-------------+ +------------+ +-----------+ +-----------+ | | | | +-------------+ +------------+ +-----------+ +-----------+ | |
| | | | | | | | | | | | | | | | | | | | | | | |
| | | Dispatcher | | Message | | Security | | Access | | | | | | Dispatcher | | Message | | Security | | Access | | |
skipping to change at page 1, line 949 skipping to change at page 26, line 10
| | | | | | | | some MIB | | | | | | | | | | | | some MIB | | | |
| | | | | | | +------------+ | | | | | | | | | | +------------+ | | |
| | | | | | | | | | | | | | | | | | | |
+-----------------------------------------------------------------+ +-----------------------------------------------------------------+
3.3.1. An SNMP Context 3.3.1. An SNMP Context
An SNMP context, or just "context" for short, is a collection of An SNMP context, or just "context" for short, is a collection of
management information accessible by an SNMP entity. An item of management information accessible by an SNMP entity. An item of
management information may exist in more than one context. An SNMP management information may exist in more than one context. An SNMP
engine potentially has access to many contexts. entity potentially has access to many contexts.
Typically, there are many instances of each managed object type Typically, there are many instances of each managed object type
within a management domain. For simplicity, the method for within a management domain. For simplicity, the method for
identifying instances specified by the MIB module does not allow each identifying instances specified by the MIB module does not allow each
instance to be distinguished amongst the set of all instances within instance to be distinguished amongst the set of all instances within
a management domain; rather, it allows each instance to be identified a management domain; rather, it allows each instance to be identified
only within some scope or "context", where there are multiple such only within some scope or "context", where there are multiple such
contexts within the management domain. Often, a context is a contexts within the management domain. Often, a context is a
physical device, or perhaps, a logical device, although a context can physical device, or perhaps, a logical device, although a context can
also encompass multiple devices, or a subset of a single device, or also encompass multiple devices, or a subset of a single device, or
skipping to change at page 1, line 1045 skipping to change at page 28, line 11
These three values are ordered such that noAuthNoPriv is less than These three values are ordered such that noAuthNoPriv is less than
authNoPriv and authNoPriv is less than authPriv. authNoPriv and authNoPriv is less than authPriv.
Every message has an associated securityLevel. All Subsystems Every message has an associated securityLevel. All Subsystems
(Message Processing, Security, Access Control) and applications are (Message Processing, Security, Access Control) and applications are
required to either supply a value of securityLevel or to abide by the required to either supply a value of securityLevel or to abide by the
supplied value of securityLevel while processing the message and its supplied value of securityLevel while processing the message and its
contents. contents.
4. Abstract Service Interfaces. 4. Abstract Service Interfaces
Abstract service interfaces have been defined to describe the Abstract service interfaces have been defined to describe the
conceptual interfaces between the various subsystems within an SNMP conceptual interfaces between the various subsystems within an SNMP
entity. entity.
These abstract service interfaces are defined by a set of primitives These abstract service interfaces are defined by a set of primitives
that define the services provided and the abstract data elements that that define the services provided and the abstract data elements that
are to be passed when the services are invoked. This section lists are to be passed when the services are invoked. This section lists
the primitives that have been defined for the various subsystems. the primitives that have been defined for the various subsystems.
4.1. Common Primitives 4.1. Dispatcher Primitives
These primitive(s) are provided by multiple Subsystems.
4.1.1. Release State Reference Information
All Subsystems which pass stateReference information also provide a
primitive to release the memory that holds the referenced state
information:
stateRelease(
IN stateReference -- handle of reference to be released
)
4.2. Dispatcher Primitives
The Dispatcher typically provides services to the SNMP applications The Dispatcher typically provides services to the SNMP applications
via its PDU Dispatcher. This section describes the primitives via its PDU Dispatcher. This section describes the primitives
provided by the PDU Dispatcher. provided by the PDU Dispatcher.
4.2.1. Generate Outgoing Request or Notification 4.1.1. Generate Outgoing Request or Notification
The PDU Dispatcher provides the following primitive for an The PDU Dispatcher provides the following primitive for an
application to send an SNMP Request or Notification to another SNMP application to send an SNMP Request or Notification to another SNMP
entity: entity:
statusInformation = -- sendPduHandle if success statusInformation = -- sendPduHandle if success
-- errorIndication if failure -- errorIndication if failure
sendPdu( sendPdu(
IN transportDomain -- transport domain to be used IN transportDomain -- transport domain to be used
IN transportAddress -- transport address to be used IN transportAddress -- transport address to be used
skipping to change at page 1, line 1098 skipping to change at page 28, line 50
IN securityModel -- Security Model to use IN securityModel -- Security Model to use
IN securityName -- on behalf of this principal IN securityName -- on behalf of this principal
IN securityLevel -- Level of Security requested IN securityLevel -- Level of Security requested
IN contextEngineID -- data from/at this entity IN contextEngineID -- data from/at this entity
IN contextName -- data from/in this context IN contextName -- data from/in this context
IN pduVersion -- the version of the PDU IN pduVersion -- the version of the PDU
IN PDU -- SNMP Protocol Data Unit IN PDU -- SNMP Protocol Data Unit
IN expectResponse -- TRUE or FALSE IN expectResponse -- TRUE or FALSE
) )
4.2.2. Process Incoming Request or Notification PDU 4.1.2. Process Incoming Request or Notification PDU
The PDU Dispatcher provides the following primitive to pass an The PDU Dispatcher provides the following primitive to pass an
incoming SNMP PDU to an application: incoming SNMP PDU to an application:
processPdu( -- process Request/Notification PDU processPdu( -- process Request/Notification PDU
IN messageProcessingModel -- typically, SNMP version IN messageProcessingModel -- typically, SNMP version
IN securityModel -- Security Model in use IN securityModel -- Security Model in use
IN securityName -- on behalf of this principal IN securityName -- on behalf of this principal
IN securityLevel -- Level of Security IN securityLevel -- Level of Security
IN contextEngineID -- data from/at this SNMP entity IN contextEngineID -- data from/at this SNMP entity
IN contextName -- data from/in this context IN contextName -- data from/in this context
IN pduVersion -- the version of the PDU IN pduVersion -- the version of the PDU
IN PDU -- SNMP Protocol Data Unit IN PDU -- SNMP Protocol Data Unit
IN maxSizeResponseScopedPDU -- maximum size of the Response PDU IN maxSizeResponseScopedPDU -- maximum size of the Response PDU
IN stateReference -- reference to state information IN stateReference -- reference to state information
) -- needed when sending a response ) -- needed when sending a response
4.2.3. Generate Outgoing Response 4.1.3. Generate Outgoing Response
The PDU Dispatcher provides the following primitive for an The PDU Dispatcher provides the following primitive for an
application to return an SNMP Response PDU to the PDU Dispatcher: application to return an SNMP Response PDU to the PDU Dispatcher:
returnResponsePdu( returnResponsePdu(
IN messageProcessingModel -- typically, SNMP version IN messageProcessingModel -- typically, SNMP version
IN securityModel -- Security Model in use IN securityModel -- Security Model in use
IN securityName -- on behalf of this principal IN securityName -- on behalf of this principal
IN securityLevel -- same as on incoming request IN securityLevel -- same as on incoming request
IN contextEngineID -- data from/at this SNMP entity IN contextEngineID -- data from/at this SNMP entity
IN contextName -- data from/in this context IN contextName -- data from/in this context
IN pduVersion -- the version of the PDU IN pduVersion -- the version of the PDU
IN PDU -- SNMP Protocol Data Unit IN PDU -- SNMP Protocol Data Unit
IN maxSizeResponseScopedPDU -- maximum size of the Response PDU IN maxSizeResponseScopedPDU -- maximum size of the Response PDU
IN stateReference -- reference to state information IN stateReference -- reference to state information
-- as presented with the request -- as presented with the request
IN statusInformation -- success or errorIndication IN statusInformation -- success or errorIndication
) -- error counter OID/value if error ) -- error counter OID/value if error
4.2.4. Process Incoming Response PDU 4.1.4. Process Incoming Response PDU
The PDU Dispatcher provides the following primitive to pass an The PDU Dispatcher provides the following primitive to pass an
incoming SNMP Response PDU to an application: incoming SNMP Response PDU to an application:
processResponsePdu( -- process Response PDU processResponsePdu( -- process Response PDU
IN messageProcessingModel -- typically, SNMP version IN messageProcessingModel -- typically, SNMP version
IN securityModel -- Security Model in use IN securityModel -- Security Model in use
IN securityName -- on behalf of this principal IN securityName -- on behalf of this principal
IN securityLevel -- Level of Security IN securityLevel -- Level of Security
IN contextEngineID -- data from/at this SNMP entity IN contextEngineID -- data from/at this SNMP entity
IN contextName -- data from/in this context IN contextName -- data from/in this context
IN pduVersion -- the version of the PDU IN pduVersion -- the version of the PDU
IN PDU -- SNMP Protocol Data Unit IN PDU -- SNMP Protocol Data Unit
IN statusInformation -- success or errorIndication IN statusInformation -- success or errorIndication
IN sendPduHandle -- handle from sendPdu IN sendPduHandle -- handle from sendPdu
) )
4.2.5. Registering Responsibility for Handling SNMP PDUs. 4.1.5. Registering Responsibility for Handling SNMP PDUs
Applications can register/unregister responsibility for a specific Applications can register/unregister responsibility for a specific
contextEngineID, for specific pduTypes, with the PDU Dispatcher contextEngineID, for specific pduTypes, with the PDU Dispatcher
according to these primitives: according to the following primitives. The list of particular
pduTypes that an application can register for is determined by the
Message Processing Model(s) supported by the SNMP entity that
contains the PDU Dispatcher.
statusInformation = -- success or errorIndication statusInformation = -- success or errorIndication
registerContextEngineID( registerContextEngineID(
IN contextEngineID -- take responsibility for this one IN contextEngineID -- take responsibility for this one
IN pduType -- the pduType(s) to be registered IN pduType -- the pduType(s) to be registered
) )
unregisterContextEngineID( unregisterContextEngineID(
IN contextEngineID -- give up responsibility for this one IN contextEngineID -- give up responsibility for this one
IN pduType -- the pduType(s) to be unregistered IN pduType -- the pduType(s) to be unregistered
) )
Note that realizations of the registerContextEngineID and Note that realizations of the registerContextEngineID and
unregisterContextEngineID abstract service interfaces may provide unregisterContextEngineID abstract service interfaces may provide
implementation-specific ways for applications to register/deregister implementation-specific ways for applications to register/deregister
responsiblity for all possible values of the contextEngineID or responsiblity for all possible values of the contextEngineID or
pduType parameters. pduType parameters.
4.3. Message Processing Subsystem Primitives 4.2. Message Processing Subsystem Primitives
The Dispatcher interacts with a Message Processing Model to process a The Dispatcher interacts with a Message Processing Model to process a
specific version of an SNMP Message. This section describes the specific version of an SNMP Message. This section describes the
primitives provided by the Message Processing Subsystem. primitives provided by the Message Processing Subsystem.
4.3.1. Prepare Outgoing SNMP Request or Notification Message 4.2.1. Prepare Outgoing SNMP Request or Notification Message
The Message Processing Subsystem provides this service primitive for The Message Processing Subsystem provides this service primitive for
preparing an outgoing SNMP Request or Notification Message: preparing an outgoing SNMP Request or Notification Message:
statusInformation = -- success or errorIndication statusInformation = -- success or errorIndication
prepareOutgoingMessage( prepareOutgoingMessage(
IN transportDomain -- transport domain to be used IN transportDomain -- transport domain to be used
IN transportAddress -- transport address to be used IN transportAddress -- transport address to be used
IN messageProcessingModel -- typically, SNMP version IN messageProcessingModel -- typically, SNMP version
IN securityModel -- Security Model to use IN securityModel -- Security Model to use
skipping to change at page 1, line 1209 skipping to change at page 32, line 5
IN PDU -- SNMP Protocol Data Unit IN PDU -- SNMP Protocol Data Unit
IN expectResponse -- TRUE or FALSE IN expectResponse -- TRUE or FALSE
IN sendPduHandle -- the handle for matching IN sendPduHandle -- the handle for matching
-- incoming responses -- incoming responses
OUT destTransportDomain -- destination transport domain OUT destTransportDomain -- destination transport domain
OUT destTransportAddress -- destination transport address OUT destTransportAddress -- destination transport address
OUT outgoingMessage -- the message to send OUT outgoingMessage -- the message to send
OUT outgoingMessageLength -- its length OUT outgoingMessageLength -- its length
) )
4.3.2. Prepare an Outgoing SNMP Response Message 4.2.2. Prepare an Outgoing SNMP Response Message
The Message Processing Subsystem provides this service primitive for The Message Processing Subsystem provides this service primitive for
preparing an outgoing SNMP Response Message: preparing an outgoing SNMP Response Message:
result = -- SUCCESS or FAILURE result = -- SUCCESS or FAILURE
prepareResponseMessage( prepareResponseMessage(
IN messageProcessingModel -- typically, SNMP version IN messageProcessingModel -- typically, SNMP version
IN securityModel -- same as on incoming request IN securityModel -- same as on incoming request
IN securityName -- same as on incoming request IN securityName -- same as on incoming request
IN securityLevel -- same as on incoming request IN securityLevel -- same as on incoming request
skipping to change at page 1, line 1235 skipping to change at page 33, line 5
IN stateReference -- reference to state information IN stateReference -- reference to state information
-- as presented with the request -- as presented with the request
IN statusInformation -- success or errorIndication IN statusInformation -- success or errorIndication
-- error counter OID/value if error -- error counter OID/value if error
OUT destTransportDomain -- destination transport domain OUT destTransportDomain -- destination transport domain
OUT destTransportAddress -- destination transport address OUT destTransportAddress -- destination transport address
OUT outgoingMessage -- the message to send OUT outgoingMessage -- the message to send
OUT outgoingMessageLength -- its length OUT outgoingMessageLength -- its length
) )
4.3.3. Prepare Data Elements from an Incoming SNMP Message 4.2.3. Prepare Data Elements from an Incoming SNMP Message
The Message Processing Subsystem provides this service primitive for The Message Processing Subsystem provides this service primitive for
preparing the abstract data elements from an incoming SNMP message: preparing the abstract data elements from an incoming SNMP message:
result = -- SUCCESS or errorIndication result = -- SUCCESS or errorIndication
prepareDataElements( prepareDataElements(
IN transportDomain -- origin transport domain IN transportDomain -- origin transport domain
IN transportAddress -- origin transport address IN transportAddress -- origin transport address
IN wholeMsg -- as received from the network IN wholeMsg -- as received from the network
IN wholeMsgLength -- as received from the network IN wholeMsgLength -- as received from the network
skipping to change at page 1, line 1263 skipping to change at page 33, line 33
OUT PDU -- SNMP Protocol Data Unit OUT PDU -- SNMP Protocol Data Unit
OUT pduType -- SNMP PDU type OUT pduType -- SNMP PDU type
OUT sendPduHandle -- handle for matched request OUT sendPduHandle -- handle for matched request
OUT maxSizeResponseScopedPDU -- maximum size of the Response PDU OUT maxSizeResponseScopedPDU -- maximum size of the Response PDU
OUT statusInformation -- success or errorIndication OUT statusInformation -- success or errorIndication
-- error counter OID/value if error -- error counter OID/value if error
OUT stateReference -- reference to state information OUT stateReference -- reference to state information
-- to be used for possible Response -- to be used for possible Response
) )
4.4. Access Control Subsystem Primitives 4.3. Access Control Subsystem Primitives
Applications are the typical clients of the service(s) of the Access Applications are the typical clients of the service(s) of the Access
Control Subsystem. Control Subsystem.
The following primitive is provided by the Access Control Subsystem The following primitive is provided by the Access Control Subsystem
to check if access is allowed: to check if access is allowed:
statusInformation = -- success or errorIndication statusInformation = -- success or errorIndication
isAccessAllowed( isAccessAllowed(
IN securityModel -- Security Model in use IN securityModel -- Security Model in use
IN securityName -- principal who wants to access IN securityName -- principal who wants to access
IN securityLevel -- Level of Security IN securityLevel -- Level of Security
IN viewType -- read, write, or notify view IN viewType -- read, write, or notify view
IN contextName -- context containing variableName IN contextName -- context containing variableName
IN variableName -- OID for the managed object IN variableName -- OID for the managed object
) )
4.5. Security Subsystem Primitives 4.4. Security Subsystem Primitives
The Message Processing Subsystem is the typical client of the The Message Processing Subsystem is the typical client of the
services of the Security Subsystem. services of the Security Subsystem.
4.5.1. Generate a Request or Notification Message 4.4.1. Generate a Request or Notification Message
The Security Subsystem provides the following primitive to generate a The Security Subsystem provides the following primitive to generate a
Request or Notification message: Request or Notification message:
statusInformation = statusInformation =
generateRequestMsg( generateRequestMsg(
IN messageProcessingModel -- typically, SNMP version IN messageProcessingModel -- typically, SNMP version
IN globalData -- message header, admin data IN globalData -- message header, admin data
IN maxMessageSize -- of the sending SNMP entity IN maxMessageSize -- of the sending SNMP entity
IN securityModel -- for the outgoing message IN securityModel -- for the outgoing message
IN securityEngineID -- authoritative SNMP entity IN securityEngineID -- authoritative SNMP entity
IN securityName -- on behalf of this principal IN securityName -- on behalf of this principal
IN securityLevel -- Level of Security requested IN securityLevel -- Level of Security requested
IN scopedPDU -- message (plaintext) payload IN scopedPDU -- message (plaintext) payload
OUT securityParameters -- filled in by Security Module OUT securityParameters -- filled in by Security Module
OUT wholeMsg -- complete generated message OUT wholeMsg -- complete generated message
OUT wholeMsgLength -- length of the generated message OUT wholeMsgLength -- length of the generated message
) )
4.5.2. Process Incoming Message 4.4.2. Process Incoming Message
The Security Subsystem provides the following primitive to process an The Security Subsystem provides the following primitive to process an
incoming message: incoming message:
statusInformation = -- errorIndication or success statusInformation = -- errorIndication or success
-- error counter OID/value if error -- error counter OID/value if error
processIncomingMsg( processIncomingMsg(
IN messageProcessingModel -- typically, SNMP version IN messageProcessingModel -- typically, SNMP version
IN maxMessageSize -- of the sending SNMP entity IN maxMessageSize -- of the sending SNMP entity
IN securityParameters -- for the received message IN securityParameters -- for the received message
skipping to change at page 1, line 1328 skipping to change at page 35, line 5
IN securityLevel -- Level of Security IN securityLevel -- Level of Security
IN wholeMsg -- as received on the wire IN wholeMsg -- as received on the wire
IN wholeMsgLength -- length as received on the wire IN wholeMsgLength -- length as received on the wire
OUT securityEngineID -- identification of the principal OUT securityEngineID -- identification of the principal
OUT securityName -- identification of the principal OUT securityName -- identification of the principal
OUT scopedPDU, -- message (plaintext) payload OUT scopedPDU, -- message (plaintext) payload
OUT maxSizeResponseScopedPDU -- maximum size of the Response PDU OUT maxSizeResponseScopedPDU -- maximum size of the Response PDU
OUT securityStateReference -- reference to security state OUT securityStateReference -- reference to security state
) -- information, needed for response ) -- information, needed for response
4.5.3. Generate a Response Message 4.4.3. Generate a Response Message
The Security Subsystem provides the following primitive to generate a The Security Subsystem provides the following primitive to generate a
Response message: Response message:
statusInformation = statusInformation =
generateResponseMsg( generateResponseMsg(
IN messageProcessingModel -- typically, SNMP version IN messageProcessingModel -- typically, SNMP version
IN globalData -- message header, admin data IN globalData -- message header, admin data
IN maxMessageSize -- of the sending SNMP entity IN maxMessageSize -- of the sending SNMP entity
IN securityModel -- for the outgoing message IN securityModel -- for the outgoing message
skipping to change at page 1, line 1350 skipping to change at page 35, line 27
IN securityName -- on behalf of this principal IN securityName -- on behalf of this principal
IN securityLevel -- for the outgoing message IN securityLevel -- for the outgoing message
IN scopedPDU -- message (plaintext) payload IN scopedPDU -- message (plaintext) payload
IN securityStateReference -- reference to security state IN securityStateReference -- reference to security state
-- information from original request -- information from original request
OUT securityParameters -- filled in by Security Module OUT securityParameters -- filled in by Security Module
OUT wholeMsg -- complete generated message OUT wholeMsg -- complete generated message
OUT wholeMsgLength -- length of the generated message OUT wholeMsgLength -- length of the generated message
) )
4.6. Common Primitives 4.5. Common Primitives
These primitive(s) are provided by multiple Subsystems. These primitive(s) are provided by multiple Subsystems.
4.6.1. Release State Reference Information 4.5.1. Release State Reference Information
All Subsystems which pass stateReference information also provide a All Subsystems which pass stateReference information also provide a
primitive to release the memory that holds the referenced state primitive to release the memory that holds the referenced state
information: information:
stateRelease( stateRelease(
IN stateReference -- handle of reference to be released IN stateReference -- handle of reference to be released
) )
4.7. Scenario Diagrams 4.6. Scenario Diagrams
4.7.1. Command Generator or Notification Originator 4.6.1. Command Generator or Notification Originator
This diagram shows how a Command Generator or Notification Originator This diagram shows how a Command Generator or Notification Originator
application requests that a PDU be sent, and how the response is application requests that a PDU be sent, and how the response is
returned (asynchronously) to that application. returned (asynchronously) to that application.
Command Dispatcher Message Security Command Dispatcher Message Security
Generator | Processing Model Generator | Processing Model
| | Model | | | Model |
| sendPdu | | | | sendPdu | | |
|------------------->| | | |------------------->| | |
skipping to change at page 1, line 1412 skipping to change at page 37, line 5
: | | processIncomingMsg | : | | processIncomingMsg |
: | |-------------------->| : | |-------------------->|
: | | | : | | |
: | |<--------------------| : | |<--------------------|
: | | | : | | |
: |<-----------------------| | : |<-----------------------| |
| processResponsePdu | | | | processResponsePdu | | |
|<-------------------| | | |<-------------------| | |
| | | | | | | |
4.7.2. Scenario Diagram for a Command Responder Application 4.6.2. Scenario Diagram for a Command Responder Application
This diagram shows how a Command Responder or Notification Receiver This diagram shows how a Command Responder or Notification Receiver
application registers for handling a pduType, how a PDU is dispatched application registers for handling a pduType, how a PDU is dispatched
to the application after a SNMP message is received, and how the to the application after a SNMP message is received, and how the
Response is (asynchronously) send back to the network. Response is (asynchronously) send back to the network.
Command Dispatcher Message Security Command Dispatcher Message Security
Responder | Processing Model Responder | Processing Model
| | Model | | | Model |
| | | | | | | |
skipping to change at page 1, line 1473 skipping to change at page 38, line 17
SNMP-FRAMEWORK-MIB DEFINITIONS ::= BEGIN SNMP-FRAMEWORK-MIB DEFINITIONS ::= BEGIN
IMPORTS IMPORTS
MODULE-IDENTITY, OBJECT-TYPE, MODULE-IDENTITY, OBJECT-TYPE,
OBJECT-IDENTITY, OBJECT-IDENTITY,
snmpModules FROM SNMPv2-SMI snmpModules FROM SNMPv2-SMI
TEXTUAL-CONVENTION FROM SNMPv2-TC TEXTUAL-CONVENTION FROM SNMPv2-TC
MODULE-COMPLIANCE, OBJECT-GROUP FROM SNMPv2-CONF; MODULE-COMPLIANCE, OBJECT-GROUP FROM SNMPv2-CONF;
snmpFrameworkMIB MODULE-IDENTITY snmpFrameworkMIB MODULE-IDENTITY
LAST-UPDATED "9709300000Z" -- 30 September 1997 LAST-UPDATED "9710280000Z" -- 28 October 1997
ORGANIZATION "SNMPv3 Working Group" ORGANIZATION "SNMPv3 Working Group"
CONTACT-INFO "WG-email: snmpv3@tis.com CONTACT-INFO "WG-email: snmpv3@tis.com
Subscribe: majordomo@tis.com Subscribe: majordomo@tis.com
In message body: subscribe snmpv3 In message body: subscribe snmpv3
Chair: Russ Mundy Chair: Russ Mundy
Trusted Information Systems Trusted Information Systems
postal: 3060 Washington Rd postal: 3060 Washington Rd
Glenwood MD 21738 Glenwood MD 21738
USA USA
skipping to change at page 1, line 1640 skipping to change at page 41, line 40
enterprise-specific securityModel value is defined enterprise-specific securityModel value is defined
to be: to be:
enterpriseID * 256 + security model within enterpriseID * 256 + security model within
enterprise enterprise
For example, the fourth Security Model defined by For example, the fourth Security Model defined by
the enterprise whose enterpriseID is 1 would be the enterprise whose enterpriseID is 1 would be
260. 260.
The eight bits allow a maximum of 255 (256-1 This scheme for allocation of securityModel
reserved) standards based Security Models. values allows for a maximum of 255 standards-
Similarly, they allow a maximum of 255 Security based Security Models, and for a maximum of
Models per enterprise. 255 Security Models per enterprise.
It is believed that the assignment of new It is believed that the assignment of new
securityModel values will be rare in practice securityModel values will be rare in practice
because the larger the number of simultaneously because the larger the number of simultaneously
utilized Security Models, the larger the utilized Security Models, the larger the
chance that interoperability will suffer. chance that interoperability will suffer.
Consequently, it is believed that such a range Consequently, it is believed that such a range
will be sufficient. In the unlikely event that will be sufficient. In the unlikely event that
the standards committee finds this number to be the standards committee finds this number to be
insufficient over time, an enterprise number insufficient over time, an enterprise number
skipping to change at page 1, line 1708 skipping to change at page 43, line 12
An enterprise messageProcessingModel value is An enterprise messageProcessingModel value is
defined to be: defined to be:
enterpriseID * 256 + enterpriseID * 256 +
messageProcessingModel within enterprise messageProcessingModel within enterprise
For example, the fourth Message Processing Model For example, the fourth Message Processing Model
defined by the enterprise whose enterpriseID defined by the enterprise whose enterpriseID
is 1 would be 260. is 1 would be 260.
The eight bits allow a maximum of 256 standards This scheme for allocation of securityModel
based Message Processing Models. Similarly, they values allows for a maximum of 255 standards-
allow a maximum 256 Message Processing Models based Message Processing Models, and for a
per enterprise. maximum of 255 Message Processing Models per
enterprise.
It is believed that the assignment of new It is believed that the assignment of new
messageProcessingModel values will be rare messageProcessingModel values will be rare
in practice because the larger the number of in practice because the larger the number of
simultaneously utilized Message Processing Models, simultaneously utilized Message Processing Models,
the larger the chance that interoperability the larger the chance that interoperability
will suffer. It is believed that such a range will suffer. It is believed that such a range
will be sufficient. In the unlikely event that will be sufficient. In the unlikely event that
the standards committee finds this number to be the standards committee finds this number to be
insufficient over time, an enterprise number insufficient over time, an enterprise number
skipping to change at page 1, line 1811 skipping to change at page 45, line 20
means of entry and display, such as hexadecimal, means of entry and display, such as hexadecimal,
may be provided. may be provided.
For information encoded in 7-bit US-ASCII, For information encoded in 7-bit US-ASCII,
the UTF-8 encoding is identical to the the UTF-8 encoding is identical to the
US-ASCII encoding. US-ASCII encoding.
Note that when this TC is used for an object that Note that when this TC is used for an object that
is used or envisioned to be used as an index, then is used or envisioned to be used as an index, then
a SIZE restriction must be specified so that the a SIZE restriction must be specified so that the
number sub-identifiers for any object instance number of sub-identifiers for any object instance
do not exceed the limit of 128, as defined by does not exceed the limit of 128, as defined by
[RFC1905]. [RFC1905].
" "
SYNTAX OCTET STRING (SIZE (0..255)) SYNTAX OCTET STRING (SIZE (0..255))
-- Administrative assignments *************************************** -- Administrative assignments ***************************************
snmpFrameworkAdmin snmpFrameworkAdmin
OBJECT IDENTIFIER ::= { snmpFrameworkMIB 1 } OBJECT IDENTIFIER ::= { snmpFrameworkMIB 1 }
snmpFrameworkMIBObjects snmpFrameworkMIBObjects
OBJECT IDENTIFIER ::= { snmpFrameworkMIB 2 } OBJECT IDENTIFIER ::= { snmpFrameworkMIB 2 }
skipping to change at page 1, line 1923 skipping to change at page 47, line 37
} }
STATUS current STATUS current
DESCRIPTION "A collection of objects for identifying and DESCRIPTION "A collection of objects for identifying and
determining the configuration and current timeliness determining the configuration and current timeliness
values of an SNMP engine. values of an SNMP engine.
" "
::= { snmpFrameworkMIBGroups 1 } ::= { snmpFrameworkMIBGroups 1 }
END END
6. Security Considerations 6. Intellectual Property
This document describes how an implementation can include a Security
Model to protect management messages and an Access Control Model to
control access to management information.
The level of security provided is determined by the specific Security
Model implementation(s) and the specific Access Control Model
implementation(s) used.
Applications have access to data which is not secured. Applications
should take reasonable steps to protect the data from disclosure.
It is the responsibility of the purchaser of an implementation to
ensure that:
1) an implementation complies with the rules defined by this
architecture,
2) the Security and Access Control Models utilized satisfy the
security and access control needs of the organization,
3) the implementations of the Models and Applications comply with
the model and application specifications,
4) and the implementation protects configuration secrets from
inadvertent disclosure.
7. Editor's Addresses
Co-editor: Bert Wijnen
IBM T.J. Watson Research
postal: Schagen 33
3461 GL Linschoten
Netherlands
email: wijnen@vnet.ibm.com
phone: +31 348-432-794
Co-editor Dave Harrington The IETF takes no position regarding the validity or scope of any
Cabletron Systems, Inc intellectual property or other rights that might be claimed to
postal: Post Office Box 5005 pertain to the implementation or use of the technology described in
Mail Stop: Durham this document or the extent to which any license under such rights
35 Industrial Way might or might not be available; neither does it represent that it
Rochester, NH 03867-5005 has made any effort to identify any such rights. Information on the
USA IETF's procedures with respect to rights in standards-track and
email: dbh@cabletron.com standards-related documentation can be found in BCP-11. Copies of
phone: +1 603-337-7357 claims of rights made available for publication and any assurances of
licenses to be made available, or the result of an attempt made to
obtain a general license or permission for the use of such
proprietary rights by implementors or users of this specification can
be obtained from the IETF Secretariat.
Co-editor Randy Presuhn The IETF invites any interested party to bring to its attention any
BMC Software, Inc. copyrights, patents or patent applications, or other proprietary
postal: 1190 Saratoga Avenue rights which may cover technology that may be required to practice
Suite 130 this standard. Please address the information to the IETF Executive
San Jose, CA 95129 Director.
USA
email: rpresuhn@bmc.com
phone: +1 408-556-0720
8. Acknowledgements 7. Acknowledgements
This document is the result of the efforts of the SNMPv3 Working This document is the result of the efforts of the SNMPv3 Working
Group. Some special thanks are in order to the following SNMPv3 WG Group. Some special thanks are in order to the following SNMPv3 WG
members: members:
Dave Battle (SNMP Research, Inc.) Dave Battle (SNMP Research, Inc.)
Uri Blumenthal (IBM T.J. Watson Research Center) Uri Blumenthal (IBM T.J. Watson Research Center)
Jeff Case (SNMP Research, Inc.) Jeff Case (SNMP Research, Inc.)
John Curran (BBN) John Curran (BBN)
T. Max Devlin (Hi-TECH Connections) T. Max Devlin (Hi-TECH Connections)
skipping to change at page 1, line 2038 skipping to change at page 49, line 22
Jeff Case (SNMP Research, Inc.) Jeff Case (SNMP Research, Inc.)
David Harrington (Cabletron Systems Inc.) David Harrington (Cabletron Systems Inc.)
David Levi (SNMP Research, Inc.) David Levi (SNMP Research, Inc.)
Keith McCloghrie (Cisco Systems) Keith McCloghrie (Cisco Systems)
Brian O'Keefe (Hewlett Packard) Brian O'Keefe (Hewlett Packard)
Marshall T. Rose (Dover Beach Consulting) Marshall T. Rose (Dover Beach Consulting)
Jon Saperia (BGS Systems Inc.) Jon Saperia (BGS Systems Inc.)
Steve Waldbusser (International Network Services) Steve Waldbusser (International Network Services)
Glenn W. Waters (Bell-Northern Research Ltd.) Glenn W. Waters (Bell-Northern Research Ltd.)
8. Security Considerations
This document describes how an implementation can include a Security
Model to protect management messages and an Access Control Model to
control access to management information.
The level of security provided is determined by the specific Security
Model implementation(s) and the specific Access Control Model
implementation(s) used.
Applications have access to data which is not secured. Applications
should take reasonable steps to protect the data from disclosure.
It is the responsibility of the purchaser of an implementation to
ensure that:
1) an implementation complies with the rules defined by this
architecture,
2) the Security and Access Control Models utilized satisfy the
security and access control needs of the organization,
3) the implementations of the Models and Applications comply with
the model and application specifications,
4) and the implementation protects configuration secrets from
inadvertent disclosure.
9. References 9. References
[RFC1155] Rose, M., and K. McCloghrie, "Structure and Identification [RFC1155] Rose, M., and K. McCloghrie, "Structure and Identification
of Management Information for TCP/IP-based internets", STD 16, RFC of Management Information for TCP/IP-based internets", STD 16, RFC
1155, May 1990. 1155, May 1990.
[RFC1157] Case, J., M. Fedor, M. Schoffstall, and J. Davin, "The [RFC1157] Case, J., M. Fedor, M. Schoffstall, and J. Davin, "The
Simple Network Management Protocol", STD 15, RFC 1157, University Simple Network Management Protocol", STD 15, RFC 1157, University
of Tennessee at Knoxville, Performance Systems s International, of Tennessee at Knoxville, Performance Systems s International,
Performance International, and the MIT Laboratory for Computer Performance International, and the MIT Laboratory for Computer
Science, May 1990. Science, May 1990.
[RFC1212] Rose, M., and K. McCloghrie, "Concise MIB Definitions", STD [RFC1212] Rose, M., and K. McCloghrie, "Concise MIB Definitions", STD
16, RFC 1212, March 1991. 16, RFC 1212, March 1991.
[RFC1901] The SNMPv2 Working Group, Case, J., McCloghrie, K., Rose, [RFC1901] The SNMPv2 Working Group, Case, J., McCloghrie, K., Rose,
M., and S., Waldbusser, "Introduction to Community-based SNMPv2", M., and S. Waldbusser, "Introduction to Community-based SNMPv2",
RFC 1901, January 1996. RFC 1901, January 1996.
[RFC1902] The SNMPv2 Working Group, Case, J., McCloghrie, K., Rose, [RFC1902] The SNMPv2 Working Group, Case, J., McCloghrie, K., Rose,
M., and S., Waldbusser, "Structure of Management Information for M., and S. Waldbusser, "Structure of Management Information for
Version 2 of the Simple Network Management Protocol (SNMPv2)", Version 2 of the Simple Network Management Protocol (SNMPv2)",
RFC 1902, January 1996. RFC 1902, January 1996.
[RFC1903] The SNMPv2 Working Group, Case, J., McCloghrie, K., Rose, [RFC1903] The SNMPv2 Working Group, Case, J., McCloghrie, K., Rose,
M., and S. Waldbusser, "Textual Conventions for Version 2 of the M., and S. Waldbusser, "Textual Conventions for Version 2 of the
Simple Network Management Protocol (SNMPv2)", RFC 1903, January Simple Network Management Protocol (SNMPv2)", RFC 1903, January
1996. 1996.
[RFC1904] The SNMPv2 Working Group, Case, J., McCloghrie, K., Rose, [RFC1904] The SNMPv2 Working Group, Case, J., McCloghrie, K., Rose,
M., and S., Waldbusser, "Conformance Statements for Version 2 of M., and S. Waldbusser, "Conformance Statements for Version 2 of
the Simple Network Management Protocol (SNMPv2)", RFC 1904, the Simple Network Management Protocol (SNMPv2)", RFC 1904,
January 1996. January 1996.
[RFC1905] The SNMPv2 Working Group, Case, J., McCloghrie, K., Rose, [RFC1905] The SNMPv2 Working Group, Case, J., McCloghrie, K., Rose,
M., and S., Waldbusser, "Protocol Operations for Version 2 of the M., and S. Waldbusser, "Protocol Operations for Version 2 of the
Simple Network Management Protocol (SNMPv2)", RFC 1905, January Simple Network Management Protocol (SNMPv2)", RFC 1905, January
1996. 1996.
[RFC1906] The SNMPv2 Working Group, Case, J., McCloghrie, K., Rose, [RFC1906] The SNMPv2 Working Group, Case, J., McCloghrie, K., Rose,
M., and S. Waldbusser, "Transport Mappings for Version 2 of the M., and S. Waldbusser, "Transport Mappings for Version 2 of the
Simple Network Management Protocol (SNMPv2)", RFC 1906, January Simple Network Management Protocol (SNMPv2)", RFC 1906, January
1996. 1996.
[RFC1907] The SNMPv2 Working Group, Case, J., McCloghrie, K., Rose, [RFC1907] The SNMPv2 Working Group, Case, J., McCloghrie, K., Rose,
M., and S. Waldbusser, "Management Information Base for Version 2 M., and S. Waldbusser, "Management Information Base for Version 2
skipping to change at page 1, line 2104 skipping to change at page 51, line 22
[RFC1910] Waters, G., Editor, "User-based Security Model for SNMPv2", [RFC1910] Waters, G., Editor, "User-based Security Model for SNMPv2",
RFC1910, February 1996. RFC1910, February 1996.
[RFC2044] Yergeau, F., "UTF-8, a transformation format of Unicode and [RFC2044] Yergeau, F., "UTF-8, a transformation format of Unicode and
ISO 10646", RFC 2044, October 1996. ISO 10646", RFC 2044, October 1996.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997. Requirement Levels", BCP 14, RFC 2119, March 1997.
[BCP-11] Hovey, R., and S. Bradner, "The Organizations Involved in
the IETF Standards Process", BCP 11, RFC 2028, October 1996.
[SNMP-MPD] The SNMPv3 Working Group, Case, J., Harrington, D., [SNMP-MPD] The SNMPv3 Working Group, Case, J., Harrington, D.,
Wijnen, B., "Message Processing and Dispatching for the Simple Presuhn, R., and B. Wijnen, "Message Processing and Dispatching
Network Management Protocol (SNMP)", draft-ietf-snmpv3-mpc-03.txt, for the Simple Network Management Protocol (SNMP)",
August 1997. draft-ietf-snmpv3-mpc-06.txt, October 1997.
[SNMP-USM] The SNMPv3 Working Group, Blumenthal, U., Wijnen, B., "The [SNMP-USM] The SNMPv3 Working Group, Blumenthal, U., and B. Wijnen,
User-Based Security Model for Version 3 of the Simple Network "The User-Based Security Model for Version 3 of the Simple Network
Management Protocol (SNMPv3)", draft-ietf-snmpv3-usm-01.txt, Management Protocol (SNMPv3)", draft-ietf-snmpv3-usm-03.txt,
August 1997. October 1997.
[SNMP-ACM] The SNMPv3 Working Group, Wijnen, B., Presuhn, R., [SNMP-ACM] The SNMPv3 Working Group, Wijnen, B., Presuhn, R., and K.
McCloghrie, K., "View-based Access Control Model for the Simple McCloghrie, "View-based Access Control Model for the Simple
Network Management Protocol (SNMP)", draft-ietf-snmpv3-acm-02.txt, Network Management Protocol (SNMP)", draft-ietf-snmpv3-acm-04.txt,
August 1997. October 1997.
[SNMP-APPL] The SNMPv3 Working Group, Levi, D. B., Meyer, P., [SNMP-APPL] The SNMPv3 Working Group, Levi, D. B., Meyer, P., and B.
Stewart, B., "SNMPv3 Applications", Stewart, "SNMPv3 Applications", <draft-ietf-snmpv3-appl-04.txt>,
<draft-ietf-snmpv3-appl-01.txt>, August 1997 October 1997.
10. Editor's Addresses
Bert Wijnen
IBM T.J. Watson Research
Schagen 33
3461 GL Linschoten
Netherlands
Phone: +31 348-432-794
EMail: wijnen@vnet.ibm.com
Dave Harrington
Cabletron Systems, Inc
Post Office Box 5005
Mail Stop: Durham
35 Industrial Way
Rochester, NH 03867-5005
USA
Phone: +1 603-337-7357
EMail: dbh@cabletron.com
Randy Presuhn
BMC Software, Inc.
1190 Saratoga Avenue
Suite 130
San Jose, CA 95129
USA
Phone: +1 408-556-0720
EMail: rpresuhn@bmc.com
APPENDIX A APPENDIX A
A. Guidelines for Model Designers A. Guidelines for Model Designers
This appendix describes guidelines for designers of models which are This appendix describes guidelines for designers of models which are
expected to fit into the architecture defined in this document. expected to fit into the architecture defined in this document.
SNMPv1 and SNMPv2c are two SNMP frameworks which use communities to SNMPv1 and SNMPv2c are two SNMP frameworks which use communities to
provide trivial authentication and access control. SNMPv1 and SNMPv2c provide trivial authentication and access control. SNMPv1 and SNMPv2c
skipping to change at page 1, line 2408 skipping to change at page 59, line 7
control is determined. control is determined.
The persistent data used for access control should be manageable The persistent data used for access control should be manageable
using SNMP, but the Access Control Model defines whether an using SNMP, but the Access Control Model defines whether an
instantiation of the MIB is a conformance requirement. instantiation of the MIB is a conformance requirement.
The Access Control Model must provide the primitive isAccessAllowed. The Access Control Model must provide the primitive isAccessAllowed.
B. Issues B. Issues
The change log will be deleted for last call; the issues list will be The issues list will be deleted when it is time to publish as an RFC.
deleted when it is time to publish as an RFC.
B.1. Showstoppers
B.2. Open Issues B.1. Open Issues
- we need a mechanism for a manager to be able to discover what - we need a mechanism for a manager to be able to discover what
securityModels are supported by a particular implementation securityModels are supported by a particular implementation
B.3. Resolved Issues B.2. Change Log
. contextEngineID in reportPDU = snmpEngineID of report generator
. returnResponsePdu - are all parameters needed? overrides allowed?
all parameters kept for future flexibility
overrides not supported by SNMPv3
. use of IN/OUT indicators in primitives accepted
. NT/Unix-like access control - can be defined as future model
. user-friendly names? yes, but with limits
. SnmpAdminString as index? yes, but restrict sizes
. need both MMS and maxSizeResponseScopedPDU? yes.
. synchronous vs. asynchronous primitives? synchronous preferred
. should we change MIB naming? no, it is acceptable
. is it ok that USM is bound to SNMPv3? while undesirable, it is
acceptable. A cleaner model may be defined in the future.
. should securityModel "any" be supported? for ACM use, not SNMPv3
. what defines SNMPv3? a document will be published after Munich
. Is an application-level handle needed for request/response matching?
yes. create sendPduHandle
. Is wild card contextEngineID/pduType registration needed? No. This is
an internal interface, and wild carding can be supported by an
implementation, but is not required in the standard.
. Should indices be integers or SnmpAdminStrings? SnmpAdminStrings
is the consensus.
. Should protocols be identified as OIDs or Integers? OIDs
. terminology:
securityLevel rather than LoS
msgXXXX to identify message fields in SNMPv3
. OID or Integer for auth/priv protocol identifiers
Consensus: use OID
. Is Glossary needed to describe primitive parameters, or is the
expanded template adequate for this purpose?
Consensus: Terms are basically all defined in section 3.
. state_reference releases
Consensus: documents checked; we think it is OK now
. new SnmpEngineID format rules to be discussed yet.
Consensus: Limit size to be 1..32
. needs changes to meet STDGUIDE guidelines
We think we're meeting them now
. we punted snmpEngineMaxMessageSize at 2nd interim because that
info travels in each SNMPv3 message. However, we may want to
re-introduce it so that SNMPv1/v2c managers can learn the value!!
Consensus: Nobody picked up on this, so it seems not needed.
. Do we need a mechanism to discover securityModels supported
Can be decided after Munich
. add a "Decision History" section (as an appendix?)
Can be decided after Munich
B.3.1. Issues discussed at second Interim Meeting:
. A "readable" introduction supplement may be done after Munich.
. Applications are responsible for retries, but implementations may
differ.
. TCs should not be defined just to describe primitive parameters.
If they cannot be described adequately in text, they can be defined
in a Glossary. Avoid describing implementation details.
. Is SnmpAdminString appropriate for all strings, such as
securityIdentifier and context and group? These had different
sizes and semantics. size and semantics may be defined in
syntax and description of OBJECT
. AdminString has size (0..255); revisit for UTF-8 discussions
. securityModel #s - 00 for IETF standards; from v2* documents
. protocol IDs - integer or OID? voted 13-0 for OID.
. uniqueness of securityName
. mapping between principal and securityName is outside scope of WG.
. principals may have more than one securityName in an entity
. mappings may exist between many types of MDID and a single
securityName
. mappings may exist between different (model, Name) and the same
securityName by varying the model or the Name.
. the securityName and a MDID may be identical. This can be defined
by the Security Model.
(user,"public") may map to securityName "public"
. [securityName, securityModel] yields zero or one MDName, with
exceptions for backwards compatibility. The exception is defined
by the model, and the problems are the province of the model to
resolve.
B.4. Change Log
Current version Current version
- Changed MIB objects from Integer32 to INTEGER to match USM - Minor layout and editorial clarifications.
fields.
- changed "network management" to simply "management"
- added caveat to EngineID selection algorithm
- Added language in register/deregister ASI to permit
implementation-specific wildcarding, as agreed in Munich.
- re-worded description of maxSizeResponseScopedPDU
- added RFC 2119 words and referece
- added reference for UTF-8
- removed "none" reserved value from SnmpSecurityModel textual
convention, changed "any" value from 255 to zero.
- modifications to SnmpAdminString agreed to in Munich meeting
- updated editor list
- converted to nroff, with some minor layout changes
[version 4.14]
. formatting
. pagination
[version 4.13]
. new acknowledgements
. updated references
. updated issues list
. ordered security, editors, acknowledgements, references sections
. checked line lengths
[version 4.12]
. cleanup
. added expectResponse to processIncomingMsg to address Levi-raised
concern
. acknowledgements
. MIB checked by SMICng
. post to snmpv3 mailing list
[version 4.11]
. Change Primitives between MP and SEC to try and address the issue
of architectural binding to message format.
. Added securityName and securityLevel to the returnResponsePdu
primitive so that architecturally it could be different for a
request and a response.
. Rename processMsg primitive to processIncomingMsg
[version 4.10]
. spell check
[version 4.9]
. editorial changes
. fix SnmpEngineID TC
. add a note to SnmpAdminString
. rename title of section 1.1
. expand description of Dispatcher a bit
[version 4.8]
. Added parameter pduVersion on primitives:
sendPdu
processPdu
returnResponsePdu
processResponsePdu
prepareDataElements
prepareOutgoingMessage
prepareResponseMessage
. Added parameter messageProcessingModel on the primitive:
processPdu
processResponsePdu
returnResponsePdu
. Removed messageProcessingModel parameter from primitives:
registerContextEngineID
unregisterContextEngineID
. Renamed SNMP Version Multiplexer to Dispatcher
. Renamed Version Multiplexer to Message Multiplexer
. Renamed Application Multiplexer to PDU Dispatcher
. Rearranged some parameters in various Primitives so the sequence
of parameters is now more consistent.
[version 4.7]
. editorial cleanup
. changed asterisk text
. modified snmpv3 framework description to eliminate dependencies
. reorder 4.2.x to reflect transaction order
. changed SnmpEngineID size to 1..32
[version 4.6]
. Changes to use synchronous primitives where possible
. Changes to describe SNMP Version Multiplexer
. Remove (empty) glossary
. Redraw documentation figure
. Redraw Operational Overview Figure
. Remove old section 4 (Architectural Elements of Procedure)
These moved to the MP document into the SNMP Version Multiplexer
section.
. Move Overview of all primitives from Appendix to Section 4.
. Simplify Appendix A to just described Model Designer Guidelines
and refer back to section 4 for specific primitives
. Remove Appendix B (An Evolutionary Architecture - Design Goals)
. added design decision regarding security
. Included latest Snmp SecurityModel TC (as it was actually posted
to the SNMPv3 mailing list).
[version 4.5]
. start with <draft-ietf-snmpv3-next-gen-arch-03.txt>
. change vendor to implementor
. change LoS to securityLevel
. remove mention of enterprise
. change Internet Management Framework to SNMP Management Framework
. modify usage of "frameworks" to improve internal consistency.
. change Message Processing Abstract Service Interface to
Application Multiplexor
. change description of SNMP engine
. moved "one-to-one association" for entity and engine to discussion
of engine.
. changed distributing to dispatching
. added asterisks to indicate v3* items are also not required.
. changed "community access control" to "other access control"
. added TC for SnmpMessageProcessingModel
. modified Security Considerations
. modified acknowledgements
[version 4.4]
. Fixed one error in the MIB (found with SMICng)
. Reformatted text for SnmpAdminString, no change in text.
. Changed text for SnmpEngineID.. this is still under discussion.
But this new text seems to be getting close to what we want.
. Added an issue w.r.t. snmpEngineMaxMessageSize
. adapt Primitive names and parameters to very latest (July 11) names
. removed blank lines before the .p page controls.
. publish as <draft-ietf-snmpv3-next-gen-arch-03.txt>
[version 4.3]
. some minor editing adjustments
[version 4.2]
. modify abstract so there is no requirement for one entity
to contain both a command generator and a notification receiver.
. modify Introduction list of entities which are meant to be
supported
. reorganized sections 1 through 4 for more consistency in contents.
. described section contents in Introduction:Target Audience
. move documentation descriptions to section 2
. rewrite section 4 to be more like a real elements of procedure.
. modified SnmpSecurityModel and SnmpEngineID definitions
. replaced MIB with Bert's replacement
. added Randy's TC for SnmpAdminString
. modified the example algorithm text for SnmpEngineID
. rewrote security considerations for brevity.
. modified "context" description
. moved "Threats" to Goals/Requirements
. eliminated snmpEngineMaxMessageSize object
. posted to snmpv3 (by DBH)
[version 4.1]
. Adopt "abstract" to new terminology
. Addressed all comments I (BW) made to DBH in an earlier email
. Changed Introduction section to new terminology
. changed wording for "implementation" to indicate it may contain
multiple models.
. Section 2. Started some wording on Goals and Design decisions
. Added the overview picture of a traditional agent and a
traditional manager. This is in section 2.
. Changed overview figure in section 3. to address the comments
by Dave Levi. It now lists the type of applications
. At various places ensure that text (easily) fits within 72
columns as required by RFC-editors Guidelines document.
. Section 2.3 (new section) has the documents set overview.
I verified the claims about standards. Not sure I worded the
SNMPv2 std correctly,. We'll hear it if we did it wrong.
. Section 2.4 (new section) gives overview of SNMP entities based
on modified Dave Levi figure. I (Bert) wonder however if it would
not be better to move it to after section 3.1.13
. Section 3. Added more figures... please let us know if you find
then useful and/or helpful. We could also move these back to
section 2 if such makes more sense.
. Added a picture in section 3.2.
It also shows some of access control, so not sure it really fits
here, although it does map principal to model-dependent security
ID to securityName
. Replace "<" with "is lower than" in section 3.4.3 which seems
better in a text document.
. Renamed section 4.1 to "SNMP engine processing" instead of
"The Message Processing Subsystem" because the transport
mappings, mpc multiplexor and such is done in ARCH document so
it is done "in general in the engine" and it passes a specific
message to a Message Processing Subsystem.
. "bulletized" some stuff in section 4.2 and 4.3.
Dave, this is just how I (Bert) like it better. Feel free to
undo it if you strongly disagree
. Section 4.3 changed "initiate a transaction" to "originate a
notification".
. Inserted title line for section 4.4 (I think it was missing)
I have named it "Information Model" in accordance with the change
I made (after Russ's comments) in the document figure to lump SMI,
TC and Conformance together.
. Inserted a title for section 4.5 named "Operational Model" to
get in sync with the the lumping together of ProtoOps and Transport
Mappings in document overview
. Renumber section 4.4.4 to 4,5,1 and added 4.5.2 to follow the
document overview figure. If we really want to follow it, then
maybe we should also reorder some of these sections. Like
Access Control seems specifically misplaced. So I decided to move
it before applications as section 4.3, so the 4.x above should
all be read as 4.x+1
. Removed size from SnmpEngineID TC... why did you limit it to
(0..2048). Did we not decide to leave it open?
. Should we not remove snmpEngineMaxMessageSize from the MIB.
That was agreed at 2nd interim. It travels in every message and so
seems to be useless. However, I think it could indeed still help
SNMPv1 or SNMPv2c managers.
. I kept your definitions of registration-points for auth and priv
protocols, but my recollection is that they would be completely
removed from ARCH and that it would all be done in SEC document.
. Modified Security Considerations. Was still talking about LPM.
. Appendix. I am still wondering if we need to use capitals for
things like "Security Model" "Subsystem" and such. This is only
an appendix... but we better be consistent, no? Anyway
I changed it so it is consistent (at least I tried).
. Appendix, renamed imf to snmpFramework
. Appendix, changed state_reference and state_release to
stateReference and stateRelease to be consistent with other names
for abstract data and primitives.
. A.2 changed MessageEngine to SNMP engine
. Fixed ASI primitives to be in sync with SEC document.
I also thought that our ARCH document-outline wanted to at least
have the primitives listed within the main body of the text, no?
. Adapted send_pdu to sendPdu primitive as reconciled by Randy
In fact I made sure all primitives are in-line with current
agreement on names and parameters.
. Rename title of A.2.4 and A.2.5 so it fits on 1 line in contents
. I did not look at appendix B. That is your (DBH) specialty is it
not ? ;-).
. Quick simple spell check done with "spell" on AIX
[version 4.0]
. move section 7 - Model Requirements to an appendix
. move Section 3 - Design Goals to an appendix
. modified Section 5 - Naming
. remove "possibly multiple"
. moved Section 5 to Section 3
. change orangelets to applications
. modify description of applications
. change scopedPDU-MMS and PDU-MMS to maxSizeResponseScopedPDU
. change Scoped-PDU and ScopedPDU to scopedPDU (no dash, lower case S)
. change imfxxx to snmpFrameworkxxx
. change security-entity to principal
. change securityIdentity to securityName
. change MIID to securityName
. eliminate all reference to groupName or group
. LoS ordering noAuthNoPriv < authNoPriv < authPriv
. Los TC naming - noAuthNoPriv(1), authNoPriv(2), authPriv(3)
. remove TCs not used in MIBs - securityIdentity TC etc
. changed Message Processing and Control to Message Processing
. changed future tense to present tense
. eliminate messageEngine
. added/updated primitives
. addressed issues raised on the mailing list
[version 3.1]
. change securityIdentity to MIID
. write text to explain the differences between security-identities,
model-dependent identifiers, and model-independent identifiers.
. write text to explain distinction within the LCD of the security
data, the access control data, and the orangelet data.
. identify issues
. publish as <draft-ietf-snmpv3-next-gen-arch-02.txt>
[version 3.0]
. add section on threats for message security
. add section on threats for access control
. change application to orangelet
. remove references to F-Ts
. change securityIdentity to security-identity
. change securityCookie to securityIdentity
. the format of securityIdentity is defined by the model
. add securityModel to passed parameters as needed
. eliminate group from passed parameters
. remove unused IMPORTS
. add glossary section with initial set of words to define
. differentiate the messageEngine from the contextEngine
. eliminate the term SNMPng
. rewrote 1.1. A Note on Terminology
. eliminated assumptions about SNMP processing always being
message related
. rewrote 4.x to reflect new thinking
. rewrote 5.x to reflect new thinking
. rewrote 6.x (the MIB) to reflect new thinking
. added MIB objects at this level (previously only TCs)
. rewrote 7.x
. sent to v3edit list
Table of Contents
1. Introduction ................................................... 2
1.1. Overview ..................................................... 2
1.2. SNMP ......................................................... 2
1.3. Goals of this Architecture ................................... 3
1.4. Security Requirements of this Architecture ................... 4
1.5. Design Decisions ............................................. 5
2. Documentation Overview ......................................... 6
2.1. Document Roadmap ............................................. 8
2.2. Applicability Statement ...................................... 8
2.3. Coexistence and Transition ................................... 8
2.4. Transport Mappings ........................................... 8
2.5. Message Processing ........................................... 9
2.6. Security ..................................................... 9
2.7. Access Control ............................................... 9
2.8. Protocol Operations .......................................... 10
2.9. Applications ................................................. 10
2.10. Structure of Management Information ......................... 10
2.11. Textual Conventions ......................................... 10
2.12. Conformance Statements ...................................... 11
2.13. Management Information Base Modules ......................... 11
2.13.1. SNMP Instrumentation MIBs ................................. 11
2.14. SNMP Framework Documents .................................... 11
3. Elements of the Architecture ................................... 12
3.1. The Naming of Entities ....................................... 12
3.1.1. SNMP entity ................................................ 13
3.1.2. SNMP engine ................................................ 13
3.1.3. snmpEngineID ............................................... 14
3.1.4. Dispatcher ................................................. 14
3.1.5. Message Processing Subsystem ............................... 15
3.1.6. Message Processing Model ................................... 15
3.1.7. Security Subsystem ......................................... 16
3.1.8. Security Model ............................................. 16
3.1.9. Security Protocol .......................................... 16
3.1.10. Access Control Subsystem .................................. 17
3.1.11. Access Control Model ...................................... 17
3.1.12. Applications .............................................. 17
3.1.13. SNMP Manager .............................................. 18
3.1.14. SNMP Agent ................................................ 19
3.2. The Naming of Identities ..................................... 20
3.2.1. Principal .................................................. 20
3.2.2. securityName ............................................... 20
3.2.3. Model-dependent security ID ................................ 21
3.3. The Naming of Management Information ......................... 22
3.3.1. An SNMP Context ............................................ 23
3.3.2. contextEngineID ............................................ 23
3.3.3. contextName ................................................ 24
3.3.4. scopedPDU .................................................. 24
3.4. Other Constructs ............................................. 24
3.4.1. maxSizeResponseScopedPDU ................................... 24
3.4.2. Local Configuration Datastore .............................. 24
3.4.3. securityLevel .............................................. 24
4. Abstract Service Interfaces. .................................. 25
4.1. Common Primitives ............................................ 25
4.1.1. Release State Reference Information ........................ 25
4.2. Dispatcher Primitives ........................................ 25
4.2.1. Generate Outgoing Request or Notification .................. 25
4.2.2. Process Incoming Request or Notification PDU ............... 26
4.2.3. Generate Outgoing Response ................................. 27
4.2.4. Process Incoming Response PDU .............................. 27
4.2.5. Registering Responsibility for Handling SNMP PDUs. ........ 27
4.3. Message Processing Subsystem Primitives ...................... 28
4.3.1. Prepare Outgoing SNMP Request or Notification Message ...... 28
4.3.2. Prepare an Outgoing SNMP Response Message .................. 29
4.3.3. Prepare Data Elements from an Incoming SNMP Message ........ 30
4.4. Access Control Subsystem Primitives .......................... 30
4.5. Security Subsystem Primitives ................................ 31
4.5.1. Generate a Request or Notification Message ................. 31
4.5.2. Process Incoming Message ................................... 31
4.5.3. Generate a Response Message ................................ 32
4.6. Common Primitives ............................................ 32
4.6.1. Release State Reference Information ........................ 32
4.7. Scenario Diagrams ............................................ 33
4.7.1. Command Generator or Notification Originator ............... 33
4.7.2. Scenario Diagram for a Command Responder Application ....... 34
5. Managed Object Definitions for SNMP Management Frameworks ...... 35
6. Security Considerations ........................................ 44
7. Editor's Addresses ............................................. 45
8. Acknowledgements ............................................... 45
9. References ..................................................... 47
A. Guidelines for Model Designers ................................. 49
A.1. Security Model Design Requirements ........................... 49
A.1.1. Threats .................................................... 49
A.1.2. Security Processing ........................................ 50
A.1.3. Validate the security-stamp in a received message .......... 50
A.1.4. Security MIBs .............................................. 51
A.1.5. Cached Security Data ....................................... 51
A.2. Message Processing Model Design Requirements ................. 51
A.2.1. Receiving an SNMP Message from the Network ................. 52
A.2.2. Sending an SNMP Message to the Network ..................... 52
A.3. Application Design Requirements .............................. 52
A.3.1. Applications that Initiate Messages ........................ 53
A.3.2. Applications that Receive Responses ........................ 53
A.3.3. Applications that Receive Asynchronous Messages ............ 53
A.3.4. Applications that Send Responses ........................... 54
A.4. Access Control Model Design Requirements ..................... 54 - Adjusted layout per RFC 2223 and added copyright statements
required by RFC 2026.
B. Issues ......................................................... 55 - Removed duplicate description of common primitives.
B.1. Showstoppers ................................................. 55 C. Full Copyright Statement
B.2. Open Issues .................................................. 55 Copyright (C) The Internet Society (1997). All Rights Reserved.
B.3. Resolved Issues .............................................. 55 This document and translations of it may be copied and furnished to
others, and derivative works that comment on or otherwise explain it
or assist in its implmentation may be prepared, copied, published and
distributed, in whole or in part, without restriction of any kind,
provided that the above copyright notice and this paragraph are
included on all such copies and derivative works. However, this
document itself may not be modified in any way, such as by removing
the copyright notice or references to the Internet Society or other
Internet organizations, except as needed for the purpose of
developing Internet standards in which case the procedures for
copyrights defined in the Internet Standards process must be
followed, or as required to translate it into languages other than
English.
B.3.1. Issues discussed at second Interim Meeting: ................ 56 The limited permissions granted above are perpetual and will not be
revoked by the Internet Society or its successors or assigns.
B.4. Change Log ................................................... 56 This document and the information contained herein is provided on an
"AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION
HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
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