• Share
  • Email
  • Embed
  • Like
  • Save
  • Private Content
Rfc3411
 

Rfc3411

on

  • 798 views

 

Statistics

Views

Total Views
798
Views on SlideShare
798
Embed Views
0

Actions

Likes
0
Downloads
5
Comments
0

0 Embeds 0

No embeds

Accessibility

Categories

Upload Details

Uploaded via as Adobe PDF

Usage Rights

© All Rights Reserved

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Processing…
Post Comment
Edit your comment

    Rfc3411 Rfc3411 Document Transcript

    • Architecture for SNMP Management Frameworks December 2002 RFC: 3411 Network Dictionary http://www.javvin.com/networkdiction- ary.html Network Protocols Map http://www.javvin.com/map.html Network Working Group D. Harrington Request for Comments: 34 Enterasys Networks Network Security Map STD: 62 R. Presuhn http://www.javvin.com/securitymap. Obsoletes: 257 BMC Software, Inc. html Wireless Communications Category: Standards Track B. Wijnen Technology Map Lucent Technologies http://www.javvin.com/wirelessmap. December 2002 html Network Protocols Hand- book http://www.javvin.com/model.html An Architecture for Describing Simple Network TCP/IP Quick Guide http://www.javvin.com/tcpipguide.html Management Protocol (SNMP) Management Frameworks Ethernet Quick Guide http://www.javvin.com/ethernetguide. html Packet Analyzer http://www.javvin.com/packet.html DiskShare http://www.javvin.com/diskshare.html DiskAccess http://www.javvin.com/diskaccess.html LANsurveyor http://www.javvin.com/LANsurveyor. html CyberGauge http://www.javvin.com/CyberGauge. html Easy Network Service Monitor http://www.javvin.com/easy.html Business Card Scanner http://www.javvin.com/businesscard- scanner.html Color Cards and Picture Scanner http://www.javvin.com/colorcardscan- ner.html Portable Document Scan- ner http://www.javvin.com/portablescan- ner.html www.javvin.com www.networkdictionary. com [ Page  ]
    • Architecture for SNMP Management Frameworks December 2002 Status of this Memo Network Dictionary http://www.javvin.com/networkdiction- ary.html This document specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the quot;Internet Official Network Protocols Map Protocol Standardsquot; (STD ) for the standardization state and status of this protocol. Distribution of this http://www.javvin.com/map.html memo is unlimited. Network Security Map Copyright Notice http://www.javvin.com/securitymap. html Copyright (C) The Internet Society (2002). All Rights Reserved. Wireless Communications Technology Map Abstract http://www.javvin.com/wirelessmap. html Network Protocols Hand- This document describes an architecture for describing Simple Network Management Protocol (SNMP) Management Frameworks. The architecture is designed to be modular to allow the evolution of the SNMP book protocol standards over time. The major portions of the architecture are an SNMP engine containing a http://www.javvin.com/model.html Message Processing Subsystem, a Security Subsystem and an Access Control Subsystem, and possibly TCP/IP Quick Guide multiple SNMP applications which provide specific functional processing of management data. This docu- ment obsoletes RFC 257. http://www.javvin.com/tcpipguide.html Ethernet Quick Guide http://www.javvin.com/ethernetguide. html Packet Analyzer http://www.javvin.com/packet.html DiskShare http://www.javvin.com/diskshare.html DiskAccess http://www.javvin.com/diskaccess.html LANsurveyor http://www.javvin.com/LANsurveyor. html CyberGauge http://www.javvin.com/CyberGauge. html Easy Network Service Monitor http://www.javvin.com/easy.html Business Card Scanner http://www.javvin.com/businesscard- scanner.html Color Cards and Picture Scanner http://www.javvin.com/colorcardscan- ner.html Portable Document Scan- ner http://www.javvin.com/portablescan- ner.html www.javvin.com www.networkdictionary. com [ Page 2 ]
    • Architecture for SNMP Management Frameworks December 2002 Table of Contents Network Dictionary http://www.javvin.com/networkdiction- ary.html . Introduction ...................................................................................................5 Network Protocols Map .. Overview ...............................................................................................5 http://www.javvin.com/map.html .2. SNMP ....................................................................................................5 .3. Goals of this Architecture ......................................................................6 Network Security Map .4. Security Requirements of this Architecture ..........................................6 http://www.javvin.com/securitymap. .5. Design Decisions ...................................................................................7 html Wireless Communications Technology Map 2. Documentation Overview .............................................................................7 http://www.javvin.com/wirelessmap. 2.. Document Roadmap ..............................................................................8 html 2.2. Applicability Statement .........................................................................8 Network Protocols Hand- 2.3. Coexistence and Transition ...................................................................8 book 2.4. Transport Mappings ..............................................................................9 http://www.javvin.com/model.html 2.5. Message Processing ..............................................................................9 TCP/IP Quick Guide 2.6. Security .................................................................................................9 http://www.javvin.com/tcpipguide.html 2.7. Access Control ......................................................................................9 2.8. Protocol Operations ...............................................................................9 Ethernet Quick Guide 2.9. Applications .........................................................................................0 http://www.javvin.com/ethernetguide. 2.0. Structure of Management Information ..............................................0 html 2.. Textual Conventions .......................................................................... Packet Analyzer 2.2. Conformance Statements .................................................................. http://www.javvin.com/packet.html 2.3. Management Information Base Modules .......................................... DiskShare 2.3.. SNMP Instrumentation MIBs ......................................................... http://www.javvin.com/diskshare.html 2.4. SNMP Framework Documents ......................................................... DiskAccess 3. Elements of the Architecture ....................................................................... http://www.javvin.com/diskaccess.html 3.. The Naming of Entities .......................................................................2 LANsurveyor 3... SNMP engine ...................................................................................2 http://www.javvin.com/LANsurveyor. 3.... snmpEngineID ...............................................................................2 html 3...2. Dispatcher .....................................................................................3 CyberGauge 3...3. Message Processing Subsystem ....................................................3 http://www.javvin.com/CyberGauge. 3...3.. Message Processing Model ........................................................3 html 3...4. Security Subsystem .......................................................................3 Easy Network Service 3...4.. Security Model ...........................................................................4 Monitor 3...4.2. Security Protocol ........................................................................4 http://www.javvin.com/easy.html 3..2. Access Control Subsystem ...............................................................4 Business Card Scanner 3..2.. Access Control Model ...................................................................4 http://www.javvin.com/businesscard- 3..3. Applications ......................................................................................4 scanner.html 3..3.. SNMP Manager .............................................................................5 Color Cards and Picture 3..3.2. SNMP Agent .................................................................................5 Scanner 3.2. The Naming of Identities ....................................................................6 http://www.javvin.com/colorcardscan- 3.2.. Principal ...........................................................................................7 ner.html Portable Document Scan- 3.2.2. securityName ....................................................................................7 ner 3.2.3. Model-dependent security ID ...........................................................7 http://www.javvin.com/portablescan- 3.3. The Naming of Management Information ..........................................7 ner.html 3.3.. An SNMP Context ............................................................................8 www.javvin.com 3.3.2. contextEngineID ..............................................................................9 3.3.3. contextName ....................................................................................9 www.networkdictionary. 3.3.4. scopedPDU .......................................................................................9 com [ Page 3 ]
    • Architecture for SNMP Management Frameworks December 2002 3.4. Other Constructs ..................................................................................9 Network Dictionary http://www.javvin.com/networkdiction- 3.4.. maxSizeResponseScopedPDU .........................................................9 ary.html 3.4.2. Local Configuration Datastore .........................................................9 3.4.3. securityLevel ....................................................................................9 Network Protocols Map http://www.javvin.com/map.html 4. Abstract Service Interfaces .........................................................................9 Network Security Map 4.. Dispatcher Primitives ..........................................................................20 http://www.javvin.com/securitymap. 4.1.1. Generate Outgoing Request or Notification .....................................20 html 4.1.2. Process Incoming Request or Notification PDU ..............................20 Wireless Communications 4..3. Generate Outgoing Response ...........................................................20 Technology Map 4..4. Process Incoming Response PDU ....................................................2 http://www.javvin.com/wirelessmap. html 4..5. Registering Responsibility for Handling SNMP PDUs ...................2 Network Protocols Hand- 4.2. Message Processing Subsystem Primitives .........................................2 book 4.2.1. Prepare Outgoing SNMP Request or Notification Message ............2 http://www.javvin.com/model.html 4.2.2. Prepare an Outgoing SNMP Response Message..............................22 TCP/IP Quick Guide 4.2.3. Prepare Data Elements from an Incoming SNMP Message ............22 http://www.javvin.com/tcpipguide.html 4.3. Access Control Subsystem Primitives.................................................23 4.4. Security Subsystem Primitives ............................................................23 Ethernet Quick Guide 4.4.1. Generate a Request or Notification Message ...................................23 http://www.javvin.com/ethernetguide. 4.4.2. Process Incoming Message ..............................................................23 html 4.4.3. Generate a Response Message .........................................................23 Packet Analyzer 4.5. Common Primitives ............................................................................24 http://www.javvin.com/packet.html 4.5.. Release State Reference Information ...............................................24 4.6. Scenario Diagrams ..............................................................................24 DiskShare 4.6.1. Command Generator or Notification Originator ..............................24 http://www.javvin.com/diskshare.html 4.6.2. Scenario Diagram for a Command Responder Application .............25 DiskAccess http://www.javvin.com/diskaccess.html 5. Managed Object Definitions for SNMP Management Frameworks ...........26 LANsurveyor 6. IANA Considerations ..................................................................................33 http://www.javvin.com/LANsurveyor. html 6.. Security Models ..................................................................................33 6.2. Message Processing Models ...............................................................33 CyberGauge 6.3. SnmpEngineID Formats ......................................................................33 http://www.javvin.com/CyberGauge. html 7. Intellectual Property ....................................................................................33 Easy Network Service Monitor 8. Acknowledgements .....................................................................................33 http://www.javvin.com/easy.html Business Card Scanner 9. Security Considerations ..............................................................................34 http://www.javvin.com/businesscard- scanner.html 0. References .................................................................................................35 Color Cards and Picture 0.. Normative References .......................................................................35 Scanner 0.2. Informative References .....................................................................36 http://www.javvin.com/colorcardscan- ner.html Portable Document Scan- Appendix A .....................................................................................................36 ner A. Guidelines for Model Designers ...........................................................36 http://www.javvin.com/portablescan- A.. Security Model Design Requirements ................................................36 ner.html A... Threats .............................................................................................37 www.javvin.com A..2. Security Processing .........................................................................37 www.networkdictionary. A..3. Validate the security-stamp in a received message .........................37 com A..4. Security MIBs .................................................................................37 [ Page 4 ]
    • Architecture for SNMP Management Frameworks December 2002 A..5. Cached Security Data ......................................................................38 Network Dictionary http://www.javvin.com/networkdiction- A.2. Message Processing Model Design Requirements .............................38 ary.html A.2.. Receiving an SNMP Message from the Network ...........................38 A.2.2. Sending an SNMP Message to the Network ...................................38 Network Protocols Map http://www.javvin.com/map.html A.3. Application Design Requirements ......................................................38 A.3.. Applications that Initiate Messages .................................................39 Network Security Map A.3.2. Applications that Receive Responses ..............................................39 http://www.javvin.com/securitymap. A.3.3. Applications that Receive Asynchronous Messages .......................39 html A.3.4. Applications that Send Responses ...................................................39 Wireless Communications A.4. Access Control Model Design Requirements .....................................39 Technology Map http://www.javvin.com/wirelessmap. html Editors' Addresses ............................................................................................40 Network Protocols Hand- book Full Copyright Statement ................................................................................40 http://www.javvin.com/model.html TCP/IP Quick Guide Acknowledgement ..........................................................................................40 http://www.javvin.com/tcpipguide.html Ethernet Quick Guide http://www.javvin.com/ethernetguide. html Packet Analyzer http://www.javvin.com/packet.html DiskShare http://www.javvin.com/diskshare.html DiskAccess http://www.javvin.com/diskaccess.html LANsurveyor http://www.javvin.com/LANsurveyor. html CyberGauge http://www.javvin.com/CyberGauge. html Easy Network Service Monitor http://www.javvin.com/easy.html Business Card Scanner http://www.javvin.com/businesscard- scanner.html Color Cards and Picture Scanner http://www.javvin.com/colorcardscan- ner.html Portable Document Scan- ner http://www.javvin.com/portablescan- ner.html www.javvin.com www.networkdictionary. com [ Page 5 ]
    • Architecture for SNMP Management Frameworks December 2002 1. Introduction Network Dictionary http://www.javvin.com/networkdiction- ary.html 1.1. Overview Network Protocols Map This document defines a vocabulary for describing SNMP Management Frameworks, and an architecture http://www.javvin.com/map.html for describing the major portions of SNMP Management Frameworks. Network Security Map This document does not provide a general introduction to SNMP. Other documents and books can provide http://www.javvin.com/securitymap. a much better introduction to SNMP. Nor does this document provide a history of SNMP. That also can be html found in books and other documents. Wireless Communications Technology Map Section  describes the purpose, goals, and design decisions of this architecture. http://www.javvin.com/wirelessmap. Section 2 describes various types of documents which define (elements of) SNMP Frameworks, and how html they fit into this architecture. It also provides a minimal road map to the documents which have previously Network Protocols Hand- defined SNMP frameworks. book http://www.javvin.com/model.html Section 3 details the vocabulary of this architecture and its pieces. This section is important for understand- ing the remaining sections, and for understanding documents which are written to fit within this architec- TCP/IP Quick Guide ture. http://www.javvin.com/tcpipguide.html Section 4 describes the primitives used for the abstract service interfaces between the various subsystems, models and applications within this architecture. Ethernet Quick Guide http://www.javvin.com/ethernetguide. Section 5 defines a collection of managed objects used to instrument SNMP entities within this architec- html ture. Packet Analyzer Sections 6, 7, 8, 9, 0 and  are administrative in nature. http://www.javvin.com/packet.html Appendix A contains guidelines for designers of Models which are expected to fit within this architecture. DiskShare http://www.javvin.com/diskshare.html The key words quot;MUSTquot;, quot;MUST NOTquot;, quot;REQUIREDquot;, quot;SHALLquot;, quot;SHALL NOTquot;, quot;SHOULDquot;, quot;SHOULD NOTquot;, quot;RECOMMENDEDquot;, quot;MAYquot;, and quot;OPTIONALquot; in this document are to be inter- DiskAccess preted as described in [RFC29]. http://www.javvin.com/diskaccess.html 1.2. SNMP LANsurveyor http://www.javvin.com/LANsurveyor. An SNMP management system contains: html - several (potentially many) nodes, each with an SNMP entity containing command responder and noti- CyberGauge fication originator applications, which have access to management instrumentation (traditionally called http://www.javvin.com/CyberGauge. agents); html - at least one SNMP entity containing command generator and/or notification receiver applications (tradi- Easy Network Service tionally called a manager) and, Monitor - a management protocol, used to convey management information between the SNMP entities. http://www.javvin.com/easy.html Business Card Scanner SNMP entities executing command generator and notification receiver applications monitor and control http://www.javvin.com/businesscard- managed elements. Managed elements are devices such as hosts, routers, terminal servers, etc., which are scanner.html monitored and controlled via access to their management information. Color Cards and Picture It is the purpose of this document to define an architecture which can evolve to realize effective manage- Scanner ment in a variety of configurations and environments. The architecture has been designed to meet the needs http://www.javvin.com/colorcardscan- of implementations of: ner.html Portable Document Scan- - minimal SNMP entities with command responder and/or notification originator applications (traditionally ner called SNMP agents), http://www.javvin.com/portablescan- - SNMP entities with proxy forwarder applications (traditionally called SNMP proxy agents), ner.html www.javvin.com - command line driven SNMP entities with command generator and/or notification receiver applications (traditionally called SNMP command line managers), www.networkdictionary. com - SNMP entities with command generator and/or notification receiver, plus command responder and/or [ Page 6 ]
    • Architecture for SNMP Management Frameworks December 2002 Network Dictionary notification originator applications (traditionally called SNMP mid-level managers or dual-role entities), http://www.javvin.com/networkdiction- - SNMP entities with command generator and/or notification receiver and possibly other types of appli- ary.html cations for managing a potentially very large number of managed nodes (traditionally called (network) Network Protocols Map management stations). http://www.javvin.com/map.html 1.3. Goals of this Architecture Network Security Map This architecture was driven by the following goals: http://www.javvin.com/securitymap. html - Use existing materials as much as possible. It is heavily based on previous work, informally known as Wireless Communications SNMPv2u and SNMPv2*, based in turn on SNMPv2p. Technology Map http://www.javvin.com/wirelessmap. - Address the need for secure SET support, which is considered the most important deficiency in SNMPv1 html and SNMPv2c. Network Protocols Hand- - Make it possible to move portions of the architecture forward in the standards track, even if consensus book has not been reached on all pieces. http://www.javvin.com/model.html TCP/IP Quick Guide - Define an architecture that allows for longevity of the SNMP Frameworks that have been and will be defined. http://www.javvin.com/tcpipguide.html - Keep SNMP as simple as possible. Ethernet Quick Guide - Make it relatively inexpensive to deploy a minimal conforming implementation. http://www.javvin.com/ethernetguide. html - Make it possible to upgrade portions of SNMP as new approaches become available, without disrupting Packet Analyzer an entire SNMP framework. http://www.javvin.com/packet.html - Make it possible to support features required in large networks, but make the expense of supporting a feature directly related to the support of the feature. DiskShare http://www.javvin.com/diskshare.html 1.4. Security Requirements of this Architecture DiskAccess Several of the classical threats to network protocols are applicable to the management problem and there- http://www.javvin.com/diskaccess.html fore would be applicable to any Security Model used in an SNMP Management Framework. Other threats are not applicable to the management problem. This section discusses principal threats, secondary threats, LANsurveyor and threats which are of lesser importance. http://www.javvin.com/LANsurveyor. html The principal threats against which any Security Model used within this architecture SHOULD provide protection are: CyberGauge http://www.javvin.com/CyberGauge. Modification of Information html The modification threat is the danger that some unauthorized entity may alter in-transit SNMP mes- sages generated on behalf of an authorized principal in such a way as to effect unauthorized manage- Easy Network Service ment operations, including falsifying the value of an object. Monitor http://www.javvin.com/easy.html Masquerade The masquerade threat is the danger that management operations not authorized for some principal may Business Card Scanner be attempted by assuming the identity of another principal that has the appropriate authorizations. http://www.javvin.com/businesscard- scanner.html Secondary threats against which any Security Model used within this architecture SHOULD provide pro- Color Cards and Picture tection are: Scanner Message Stream Modification http://www.javvin.com/colorcardscan- The SNMP protocol is typically based upon a connectionless transport service which may operate over ner.html any subnetwork service. The re-ordering, delay or replay of messages can and does occur through the Portable Document Scan- natural operation of many such subnetwork services. The message stream modification threat is the ner danger that messages may be maliciously re-ordered, delayed or replayed to an extent which is greater http://www.javvin.com/portablescan- than can occur through the natural operation of a subnetwork service, in order to effect unauthorized ner.html management operations. www.javvin.com Disclosure The disclosure threat is the danger of eavesdropping on the exchanges between SNMP engines. Protect- www.networkdictionary. ing against this threat may be required as a matter of local policy. com [ Page 7 ]
    • Architecture for SNMP Management Frameworks December 2002 Network Dictionary There are at least two threats against which a Security Model within this architecture need not protect, since http://www.javvin.com/networkdiction- they are deemed to be of lesser importance in this context: ary.html Network Protocols Map Denial of Service A Security Model need not attempt to address the broad range of attacks by which service on behalf of http://www.javvin.com/map.html authorized users is denied. Indeed, such denial-of-service attacks are in many cases indistinguishable from the type of network failures with which any viable management protocol must cope as a matter Network Security Map of course. http://www.javvin.com/securitymap. html Traffic Analysis Wireless Communications A Security Model need not attempt to address traffic analysis attacks. Many traffic patterns are predict- Technology Map able - entities may be managed on a regular basis by a relatively small number of management stations - and therefore there is no significant advantage afforded by protecting against traffic analysis. http://www.javvin.com/wirelessmap. html 1.5. Design Decisions Network Protocols Hand- book Various design decisions were made in support of the goals of the architecture and the security require- http://www.javvin.com/model.html ments: TCP/IP Quick Guide - Architecture http://www.javvin.com/tcpipguide.html An architecture should be defined which identifies the conceptual boundaries between the documents. Subsystems should be defined which describe the abstract services provided by specific portions of an Ethernet Quick Guide SNMP framework. Abstract service interfaces, as described by service primitives, define the abstract boundaries between documents, and the abstract services that are provided by the conceptual subsys- http://www.javvin.com/ethernetguide. tems of an SNMP framework. html Packet Analyzer - Self-contained Documents Elements of procedure plus the MIB objects which are needed for processing for a specific portion of http://www.javvin.com/packet.html an SNMP framework should be defined in the same document, and as much as possible, should not be referenced in other documents. This allows pieces to be designed and documented as independent and DiskShare self- contained parts, which is consistent with the general SNMP MIB module approach. As portions of http://www.javvin.com/diskshare.html SNMP change over time, the documents describing other portions of SNMP are not directly impacted. This modularity allows, for example, Security Models, authentication and privacy mechanisms, and DiskAccess message formats to be upgraded and supplemented as the need arises. The self-contained documents http://www.javvin.com/diskaccess.html can move along the standards track on different time-lines. LANsurveyor This modularity of specification is not meant to be interpreted as imposing any specific requirements on implementation. http://www.javvin.com/LANsurveyor. html - Threats CyberGauge The Security Models in the Security Subsystem SHOULD protect against the principal and secondary threats: modification of information, masquerade, message stream modification and disclosure. They http://www.javvin.com/CyberGauge. do not need to protect against denial of service and traffic analysis. html Easy Network Service - Remote Configuration The Security and Access Control Subsystems add a whole new set of SNMP configuration parameters. Monitor The Security Subsystem also requires frequent changes of secrets at the various SNMP entities. To http://www.javvin.com/easy.html make this deployable in a large operational environment, these SNMP parameters must be remotely Business Card Scanner configurable. http://www.javvin.com/businesscard- - Controlled Complexity scanner.html It is recognized that producers of simple managed devices want to keep the resources used by SNMP Color Cards and Picture to a minimum. At the same time, there is a need for more complex configurations which can spend Scanner more resources for SNMP and thus provide more functionality. The design tries to keep the competing http://www.javvin.com/colorcardscan- requirements of these two environments in balance and allows the more complex environments to logi- ner.html cally extend the simple environment. Portable Document Scan- ner 2. Documentation Overview http://www.javvin.com/portablescan- ner.html The following figure shows the set of documents that fit within the SNMP Architecture. www.javvin.com www.networkdictionary. com [ Page 8 ]
    • Architecture for SNMP Management Frameworks December 2002 Network Dictionary http://www.javvin.com/networkdiction- ary.html Network Protocols Map http://www.javvin.com/map.html Network Security Map http://www.javvin.com/securitymap. html Wireless Communications Technology Map http://www.javvin.com/wirelessmap. html Network Protocols Hand- book http://www.javvin.com/model.html TCP/IP Quick Guide http://www.javvin.com/tcpipguide.html Ethernet Quick Guide http://www.javvin.com/ethernetguide. html Packet Analyzer http://www.javvin.com/packet.html DiskShare http://www.javvin.com/diskshare.html DiskAccess http://www.javvin.com/diskaccess.html Each of these documents may be replaced or supplemented. This Architecture document specifically de- scribes how new documents fit into the set of documents in the area of Message and PDU handling. LANsurveyor http://www.javvin.com/LANsurveyor. 2.1. Document Roadmap html CyberGauge One or more documents may be written to describe how sets of documents taken together form specific http://www.javvin.com/CyberGauge. Frameworks. The configuration of document sets might change over time, so the quot;road mapquot; should be html maintained in a document separate from the standards documents themselves. Easy Network Service An example of such a roadmap is quot;Introduction and Applicability Statements for the Internet-Standard Monitor Management Frameworkquot; [RFC340]. http://www.javvin.com/easy.html 2.2. Applicability Statement Business Card Scanner http://www.javvin.com/businesscard- SNMP is used in networks that vary widely in size and complexity, by organizations that vary widely in scanner.html their requirements of management. Some models will be designed to address specific problems of manage- Color Cards and Picture ment, such as message security. Scanner http://www.javvin.com/colorcardscan- One or more documents may be written to describe the environments to which certain versions of SNMP ner.html or models within SNMP would be appropriately applied, and those to which a given model might be inap- Portable Document Scan- propriately applied. ner 2.3. Coexistence and Transition http://www.javvin.com/portablescan- ner.html The purpose of an evolutionary architecture is to permit new models to replace or supplement existing www.javvin.com models. The interactions between models could result in incompatibilities, security quot;holesquot;, and other un- desirable effects. www.networkdictionary. com The purpose of Coexistence documents is to detail recognized anomalies and to describe required and rec- [ Page 9 ]
    • Architecture for SNMP Management Frameworks December 2002 Network Dictionary ommended behaviors for resolving the interactions between models within the architecture. http://www.javvin.com/networkdiction- Coexistence documents may be prepared separately from model definition documents, to describe and ary.html resolve interaction anomalies between a model definition and one or more other model definitions. Network Protocols Map Additionally, recommendations for transitions between models may also be described, either in a coexis- http://www.javvin.com/map.html tence document or in a separate document. Network Security Map One such coexistence document is [RFC2576], quot;Coexistence between Version , Version 2, and Version 3 http://www.javvin.com/securitymap. of the Internet-Standard Network Management Frameworkquot;. html Wireless Communications 2.4. Transport Mappings Technology Map http://www.javvin.com/wirelessmap. SNMP messages are sent over various transports. It is the purpose of Transport Mapping documents to html define how the mapping between SNMP and the transport is done. Network Protocols Hand- book 2.5. Message Processing http://www.javvin.com/model.html A Message Processing Model document defines a message format, which is typically identified by a ver- TCP/IP Quick Guide sion field in an SNMP message header. The document may also define a MIB module for use in message http://www.javvin.com/tcpipguide.html processing and for instrumentation of version-specific interactions. An SNMP engine includes one or more Message Processing Models, and thus may support sending and Ethernet Quick Guide receiving multiple versions of SNMP messages. http://www.javvin.com/ethernetguide. html 2.6. Security Packet Analyzer http://www.javvin.com/packet.html Some environments require secure protocol interactions. Security is normally applied at two different stages: DiskShare - in the transmission/receipt of messages, and http://www.javvin.com/diskshare.html - in the processing of the contents of messages. DiskAccess http://www.javvin.com/diskaccess.html For purposes of this document, quot;securityquot; refers to message-level security; quot;access controlquot; refers to the security applied to protocol operations. LANsurveyor http://www.javvin.com/LANsurveyor. Authentication, encryption, and timeliness checking are common functions of message level security. html A security document describes a Security Model, the threats against which the model protects, the goals CyberGauge of the Security Model, the protocols which it uses to meet those goals, and it may define a MIB module to http://www.javvin.com/CyberGauge. describe the data used during processing, and to allow the remote configuration of message-level security html parameters, such as keys. Easy Network Service An SNMP engine may support multiple Security Models concurrently. Monitor 2.7. Access Control http://www.javvin.com/easy.html Business Card Scanner During processing, it may be required to control access to managed objects for operations. http://www.javvin.com/businesscard- scanner.html An Access Control Model defines mechanisms to determine whether access to a managed object should Color Cards and Picture be allowed. An Access Control Model may define a MIB module used during processing and to allow the Scanner remote configuration of access control policies. http://www.javvin.com/colorcardscan- ner.html 2.8. Protocol Operations Portable Document Scan- ner SNMP messages encapsulate an SNMP Protocol Data Unit (PDU). SNMP PDUs define the operations performed by the receiving SNMP engine. It is the purpose of a Protocol Operations document to define the http://www.javvin.com/portablescan- operations of the protocol with respect to the processing of the PDUs. Every PDU belongs to one or more ner.html of the PDU classes defined below: www.javvin.com ) Read Class: www.networkdictionary. com The Read Class contains protocol operations that retrieve management information. For example, [ Page 0 ]
    • Architecture for SNMP Management Frameworks December 2002 Network Dictionary [RFC3416] defines the following protocol operations for the Read Class: GetRequest- PDU, GetNex- tRequest-PDU, and GetBulkRequest-PDU. http://www.javvin.com/networkdiction- ary.html 2) Write Class: Network Protocols Map The Write Class contains protocol operations which attempt to modify management information. For http://www.javvin.com/map.html example, [RFC3416] defines the following protocol operation for the Write Class: SetRequest-PDU. Network Security Map 3) Response Class: http://www.javvin.com/securitymap. html The Response Class contains protocol operations which are sent in response to a previous request. For Wireless Communications example, [RFC3416] defines the following for the Response Class: Response-PDU, Report-PDU. Technology Map 4) Notification Class: http://www.javvin.com/wirelessmap. html The Notification Class contains protocol operations which send a notification to a notification receiv- Network Protocols Hand- er application. For example, [RFC3416] defines the following operations for the Notification Class: book Trapv2-PDU, InformRequest-PDU. http://www.javvin.com/model.html 5) Internal Class: TCP/IP Quick Guide http://www.javvin.com/tcpipguide.html The Internal Class contains protocol operations which are exchanged internally between SNMP en- gines. For example, [RFC3416] defines the following operation for the Internal Class: Report-PDU. Ethernet Quick Guide The preceding five classifications are based on the functional properties of a PDU. It is also useful to clas- http://www.javvin.com/ethernetguide. sify PDUs based on whether a response is expected: html 6) Confirmed Class: Packet Analyzer http://www.javvin.com/packet.html The Confirmed Class contains all protocol operations which cause the receiving SNMP engine to send back a response. For example, [RFC3416] defines the following operations for the Confirmed Class: DiskShare GetRequest-PDU, GetNextRequest-PDU, GetBulkRequest-PDU, SetRequest-PDU, and InformRe- http://www.javvin.com/diskshare.html quest-PDU. DiskAccess 7) Unconfirmed Class: http://www.javvin.com/diskaccess.html The Unconfirmed Class contains all protocol operations which are not acknowledged. For example, [RFC3416] defines the following operations for the Unconfirmed Class: Report-PDU, Trapv2-PDU, LANsurveyor and GetResponse-PDU. http://www.javvin.com/LANsurveyor. html An application document defines which Protocol Operations are supported by the application. CyberGauge 2.9. Applications http://www.javvin.com/CyberGauge. html An SNMP entity normally includes a number of applications. Applications use the services of an SNMP en- Easy Network Service gine to accomplish specific tasks. They coordinate the processing of management information operations, and may use SNMP messages to communicate with other SNMP entities. Monitor http://www.javvin.com/easy.html An applications document describes the purpose of an application, the services required of the associated Business Card Scanner SNMP engine, and the protocol operations and informational model that the application uses to perform management operations. http://www.javvin.com/businesscard- scanner.html An application document defines which set of documents are used to specifically define the structure of Color Cards and Picture management information, textual conventions, conformance requirements, and operations supported by Scanner the application. http://www.javvin.com/colorcardscan- ner.html 2.10. Structure of Management Information Portable Document Scan- ner Management information is viewed as a collection of managed objects, residing in a virtual information http://www.javvin.com/portablescan- store, termed the Management Information Base (MIB). Collections of related objects are defined in MIB ner.html modules. www.javvin.com It is the purpose of a Structure of Management Information document to establish the notation for defining objects, modules, and other elements of managed information. www.networkdictionary. com [ Page  ]
    • Architecture for SNMP Management Frameworks December 2002 2.11. Textual Conventions Network Dictionary http://www.javvin.com/networkdiction- ary.html When designing a MIB module, it is often useful to define new types similar to those defined in the SMI, but with more precise semantics, or which have special semantics associated with them. These newly Network Protocols Map defined types are termed textual conventions, and may be defined in separate documents, or within a MIB http://www.javvin.com/map.html module. Network Security Map 2.12. Conformance Statements http://www.javvin.com/securitymap. html It may be useful to define the acceptable lower-bounds of implementation, along with the actual level of Wireless Communications implementation achieved. It is the purpose of the Conformance Statements document to define the notation used for these purposes. Technology Map http://www.javvin.com/wirelessmap. 2.13. Management Information Base Modules html Network Protocols Hand- MIB documents describe collections of managed objects which instrument some aspect of a managed book node. http://www.javvin.com/model.html TCP/IP Quick Guide 2.13.1. SNMP Instrumentation MIBs http://www.javvin.com/tcpipguide.html An SNMP MIB document may define a collection of managed objects which instrument the SNMP proto- col itself. In addition, MIB modules may be defined within the documents which describe portions of the Ethernet Quick Guide SNMP architecture, such as the documents for Message processing Models, Security Models, etc. for the http://www.javvin.com/ethernetguide. purpose of instrumenting those Models, and for the purpose of allowing their remote configuration. html 2.14. SNMP Framework Documents Packet Analyzer http://www.javvin.com/packet.html This architecture is designed to allow an orderly evolution of portions of SNMP Frameworks. DiskShare Throughout the rest of this document, the term quot;subsystemquot; refers to an abstract and incomplete specifica- http://www.javvin.com/diskshare.html tion of a portion of a Framework, that is further refined by a model specification. DiskAccess A quot;modelquot; describes a specific design of a subsystem, defining additional constraints and rules for confor- http://www.javvin.com/diskaccess.html mance to the model. A model is sufficiently detailed to make it possible to implement the specification. LANsurveyor An quot;implementationquot; is an instantiation of a subsystem, conforming to one or more specific models. http://www.javvin.com/LANsurveyor. SNMP version  (SNMPv), is the original Internet-Standard Network Management Framework, as de- html scribed in RFCs 55, 57, and 22. CyberGauge SNMP version 2 (SNMPv2), is the SNMPv2 Framework as derived from the SNMPv Framework. It is http://www.javvin.com/CyberGauge. described in STD 58, RFCs 2578, 2579, 2580, and STD 62, RFCs 346, 347, and 348. SNMPv2 has no html message definition. Easy Network Service The Community-based SNMP version 2 (SNMPv2c), is an experimental SNMP Framework which supple- Monitor ments the SNMPv2 Framework, as described in [RFC90]. It adds the SNMPv2c message format, which http://www.javvin.com/easy.html is similar to the SNMPv message format. Business Card Scanner SNMP version 3 (SNMPv3), is an extensible SNMP Framework which supplements the SNMPv2 Frame- http://www.javvin.com/businesscard- work, by supporting the following: scanner.html Color Cards and Picture - a new SNMP message format, Scanner http://www.javvin.com/colorcardscan- - Security for Messages, ner.html Portable Document Scan- - Access Control, and ner - Remote configuration of SNMP parameters. http://www.javvin.com/portablescan- ner.html Other SNMP Frameworks, i.e., other configurations of implemented subsystems, are expected to also be www.javvin.com consistent with this architecture. www.networkdictionary. 3. Elements of the Architecture com [ Page 2 ]
    • Architecture for SNMP Management Frameworks December 2002 Network Dictionary This section describes the various elements of the architecture and how they are named. There are three http://www.javvin.com/networkdiction- kinds of naming: ary.html Network Protocols Map ) the naming of entities, http://www.javvin.com/map.html 2) the naming of identities, and Network Security Map 3) the naming of management information. http://www.javvin.com/securitymap. html This architecture also defines some names for other constructs that are used in the documentation. Wireless Communications Technology Map 3.1. The Naming of Entities http://www.javvin.com/wirelessmap. html An SNMP entity is an implementation of this architecture. Each such SNMP entity consists of an SNMP Network Protocols Hand- engine and one or more associated applications. book The following figure shows details about an SNMP entity and the components within it. http://www.javvin.com/model.html TCP/IP Quick Guide http://www.javvin.com/tcpipguide.html Ethernet Quick Guide http://www.javvin.com/ethernetguide. html Packet Analyzer http://www.javvin.com/packet.html DiskShare http://www.javvin.com/diskshare.html DiskAccess http://www.javvin.com/diskaccess.html LANsurveyor http://www.javvin.com/LANsurveyor. html CyberGauge http://www.javvin.com/CyberGauge. html Easy Network Service Monitor 3.1.1. SNMP engine http://www.javvin.com/easy.html Business Card Scanner An SNMP engine provides services for sending and receiving messages, authenticating and encrypting messages, and controlling access to managed objects. There is a one-to-one association between an SNMP http://www.javvin.com/businesscard- engine and the SNMP entity which contains it. scanner.html Color Cards and Picture The engine contains: Scanner http://www.javvin.com/colorcardscan- ) a Dispatcher, ner.html Portable Document Scan- 2) a Message Processing Subsystem, ner 3) a Security Subsystem, and http://www.javvin.com/portablescan- ner.html 4) an Access Control Subsystem. www.javvin.com 3.1.1.1. snmpEngineID www.networkdictionary. com Within an administrative domain, an snmpEngineID is the unique and unambiguous identifier of an SNMP [ Page 3 ]
    • Architecture for SNMP Management Frameworks December 2002 Network Dictionary engine. Since there is a one-to- one association between SNMP engines and SNMP entities, it also uniquely and unambiguously identifies the SNMP entity within that administrative domain. Note that it is possible http://www.javvin.com/networkdiction- for SNMP entities in different administrative domains to have the same value for snmpEngineID. Federa- ary.html tion of administrative domains may necessitate assignment of new values. Network Protocols Map 3.1.1.2. Dispatcher http://www.javvin.com/map.html Network Security Map There is only one Dispatcher in an SNMP engine. It allows for concurrent support of multiple versions of SNMP messages in the SNMP engine. It does so by: http://www.javvin.com/securitymap. html - sending and receiving SNMP messages to/from the network, Wireless Communications Technology Map - determining the version of an SNMP message and interacting with the corresponding Message Pro- http://www.javvin.com/wirelessmap. cessing Model, html Network Protocols Hand- - providing an abstract interface to SNMP applications for delivery of a PDU to an application. book - providing an abstract interface for SNMP applications that allows them to send a PDU to a remote http://www.javvin.com/model.html SNMP entity. TCP/IP Quick Guide http://www.javvin.com/tcpipguide.html 3.1.1.3. Message Processing Subsystem The Message Processing Subsystem is responsible for preparing messages for sending, and extracting data Ethernet Quick Guide from received messages. http://www.javvin.com/ethernetguide. html The Message Processing Subsystem potentially contains multiple Message Processing Models as shown in the next figure. Packet Analyzer http://www.javvin.com/packet.html * One or more Message Processing Models may be present. DiskShare http://www.javvin.com/diskshare.html DiskAccess http://www.javvin.com/diskaccess.html LANsurveyor http://www.javvin.com/LANsurveyor. html CyberGauge http://www.javvin.com/CyberGauge. html 3.1.1.3.1. Message Processing Model Easy Network Service Each Message Processing Model defines the format of a particular version of an SNMP message and coor- Monitor dinates the preparation and extraction of each such version-specific message format. http://www.javvin.com/easy.html Business Card Scanner 3.1.1.4. Security Subsystem http://www.javvin.com/businesscard- scanner.html The Security Subsystem provides security services such as the authentication and privacy of messages and Color Cards and Picture potentially contains multiple Security Models as shown in the following figure Scanner * One or more Security Models may be present. http://www.javvin.com/colorcardscan- ner.html Portable Document Scan- ner http://www.javvin.com/portablescan- ner.html www.javvin.com www.networkdictionary. com [ Page 4 ]
    • Architecture for SNMP Management Frameworks December 2002 Network Dictionary http://www.javvin.com/networkdiction- ary.html Network Protocols Map http://www.javvin.com/map.html Network Security Map http://www.javvin.com/securitymap. html Wireless Communications Technology Map 3.1.1.4.1. Security Model http://www.javvin.com/wirelessmap. html A Security Model specifies the threats against which it protects, the goals of its services, and the security Network Protocols Hand- protocols used to provide security services such as authentication and privacy. book 3.1.1.4.2. Security Protocol http://www.javvin.com/model.html TCP/IP Quick Guide A Security Protocol specifies the mechanisms, procedures, and MIB objects used to provide a security http://www.javvin.com/tcpipguide.html service such as authentication or privacy. Ethernet Quick Guide 3.1.2. Access Control Subsystem http://www.javvin.com/ethernetguide. html The Access Control Subsystem provides authorization services by means of one or more (*) Access Con- trol Models. Packet Analyzer http://www.javvin.com/packet.html DiskShare http://www.javvin.com/diskshare.html DiskAccess http://www.javvin.com/diskaccess.html LANsurveyor http://www.javvin.com/LANsurveyor. html CyberGauge 3.1.2.1. Access Control Model http://www.javvin.com/CyberGauge. html An Access Control Model defines a particular access decision function in order to support decisions regard- ing access rights. Easy Network Service Monitor 3.1.3. Applications http://www.javvin.com/easy.html Business Card Scanner There are several types of applications, including: http://www.javvin.com/businesscard- scanner.html - command generators, which monitor and manipulate management data, Color Cards and Picture - command responders, which provide access to management data, Scanner http://www.javvin.com/colorcardscan- - notification originators, which initiate asynchronous messages, ner.html Portable Document Scan- - notification receivers, which process asynchronous messages, ner and http://www.javvin.com/portablescan- ner.html - proxy forwarders, which forward messages between entities. www.javvin.com These applications make use of the services provided by the SNMP engine. www.networkdictionary. com [ Page 5 ]
    • Architecture for SNMP Management Frameworks December 2002 3.1.3.1. SNMP Manager Network Dictionary http://www.javvin.com/networkdiction- ary.html An SNMP entity containing one or more command generator and/or notification receiver applications (along with their associated SNMP engine) has traditionally been called an SNMP manager. Network Protocols Map http://www.javvin.com/map.html Network Security Map http://www.javvin.com/securitymap. html Wireless Communications Technology Map http://www.javvin.com/wirelessmap. html Network Protocols Hand- book http://www.javvin.com/model.html TCP/IP Quick Guide http://www.javvin.com/tcpipguide.html Ethernet Quick Guide http://www.javvin.com/ethernetguide. html Packet Analyzer http://www.javvin.com/packet.html DiskShare http://www.javvin.com/diskshare.html DiskAccess http://www.javvin.com/diskaccess.html LANsurveyor http://www.javvin.com/LANsurveyor. html 3.1.3.2. SNMP Agent CyberGauge http://www.javvin.com/CyberGauge. An SNMP entity containing one or more command responder and/or notification originator applications html (along with their associated SNMP engine) has traditionally been called an SNMP agent. Easy Network Service * One or more models may be present. Monitor http://www.javvin.com/easy.html Business Card Scanner http://www.javvin.com/businesscard- scanner.html Color Cards and Picture Scanner http://www.javvin.com/colorcardscan- ner.html Portable Document Scan- ner http://www.javvin.com/portablescan- ner.html www.javvin.com www.networkdictionary. com [ Page 6 ]
    • Architecture for SNMP Management Frameworks December 2002 Network Dictionary http://www.javvin.com/networkdiction- ary.html Network Protocols Map http://www.javvin.com/map.html Network Security Map http://www.javvin.com/securitymap. html Wireless Communications Technology Map http://www.javvin.com/wirelessmap. html Network Protocols Hand- book http://www.javvin.com/model.html TCP/IP Quick Guide http://www.javvin.com/tcpipguide.html Ethernet Quick Guide http://www.javvin.com/ethernetguide. html Packet Analyzer http://www.javvin.com/packet.html DiskShare http://www.javvin.com/diskshare.html DiskAccess http://www.javvin.com/diskaccess.html 3.2. The Naming of Identities LANsurveyor http://www.javvin.com/LANsurveyor. html CyberGauge http://www.javvin.com/CyberGauge. html Easy Network Service Monitor http://www.javvin.com/easy.html Business Card Scanner http://www.javvin.com/businesscard- scanner.html Color Cards and Picture Scanner http://www.javvin.com/colorcardscan- ner.html Portable Document Scan- ner http://www.javvin.com/portablescan- ner.html www.javvin.com www.networkdictionary. com [ Page 7 ]
    • Architecture for SNMP Management Frameworks December 2002 Network Dictionary http://www.javvin.com/networkdiction- ary.html Network Protocols Map http://www.javvin.com/map.html Network Security Map http://www.javvin.com/securitymap. html Wireless Communications Technology Map http://www.javvin.com/wirelessmap. html Network Protocols Hand- book http://www.javvin.com/model.html TCP/IP Quick Guide http://www.javvin.com/tcpipguide.html Ethernet Quick Guide http://www.javvin.com/ethernetguide. html Packet Analyzer http://www.javvin.com/packet.html 3.2.1. Principal DiskShare http://www.javvin.com/diskshare.html A principal is the quot;whoquot; on whose behalf services are provided or processing takes place. DiskAccess A principal can be, among other things, an individual acting in a particular role; a set of individuals, with http://www.javvin.com/diskaccess.html each acting in a particular role; an application or a set of applications; and combinations thereof. LANsurveyor 3.2.2. securityName http://www.javvin.com/LANsurveyor. html A securityName is a human readable string representing a principal. It has a model-independent format, and CyberGauge can be used outside a particular Security Model. http://www.javvin.com/CyberGauge. html 3.2.3. Model-dependent security ID Easy Network Service A model-dependent security ID is the model-specific representation of a securityName within a particular Monitor Security Model. http://www.javvin.com/easy.html Model-dependent security IDs may or may not be human readable, and have a model-dependent syntax. Business Card Scanner Examples include community names, and user names. http://www.javvin.com/businesscard- scanner.html The transformation of model-dependent security IDs into securityNames and vice versa is the responsibil- Color Cards and Picture ity of the relevant Security Model. Scanner 3.3. The Naming of Management Information http://www.javvin.com/colorcardscan- ner.html Portable Document Scan- Management information resides at an SNMP entity where a Command Responder Application has local ner access to potentially multiple contexts. This application uses a contextEngineID equal to the snmpEngin- eID of its associated SNMP engine. http://www.javvin.com/portablescan- ner.html www.javvin.com www.networkdictionary. com [ Page 8 ]
    • Architecture for SNMP Management Frameworks December 2002 Network Dictionary http://www.javvin.com/networkdiction- ary.html Network Protocols Map http://www.javvin.com/map.html Network Security Map http://www.javvin.com/securitymap. html Wireless Communications Technology Map http://www.javvin.com/wirelessmap. html Network Protocols Hand- book http://www.javvin.com/model.html TCP/IP Quick Guide http://www.javvin.com/tcpipguide.html Ethernet Quick Guide http://www.javvin.com/ethernetguide. html Packet Analyzer http://www.javvin.com/packet.html DiskShare http://www.javvin.com/diskshare.html DiskAccess http://www.javvin.com/diskaccess.html 3.3.1. An SNMP Context LANsurveyor http://www.javvin.com/LANsurveyor. html An SNMP context, or just quot;contextquot; for short, is a collection of management information accessible by an SNMP entity. An item of management information may exist in more than one context. An SNMP entity CyberGauge potentially has access to many contexts. http://www.javvin.com/CyberGauge. html Typically, there are many instances of each managed object type within a management domain. For sim- plicity, the method for identifying instances specified by the MIB module does not allow each instance Easy Network Service to be distinguished amongst the set of all instances within a management domain; rather, it allows each Monitor instance to be identified only within some scope or quot;contextquot;, where there are multiple such contexts within the management domain. Often, a context is a physical device, or perhaps, a logical device, although a http://www.javvin.com/easy.html context can also encompass multiple devices, or a subset of a single device, or even a subset of multiple Business Card Scanner devices, but a context is always defined as a subset of a single SNMP entity. Thus, in order to identify an http://www.javvin.com/businesscard- individual item of management information within the management domain, its contextName and contex- scanner.html tEngineID must be identified in addition to its object type and its instance. Color Cards and Picture For example, the managed object type ifDescr [RFC2863], is defined as the description of a network Scanner interface. To identify the description of device-X's first network interface, four pieces of information are http://www.javvin.com/colorcardscan- needed: the snmpEngineID of the SNMP entity which provides access to the management information at ner.html device-X, the contextName (device-X), the managed object type (ifDescr), and the instance (quot;quot;). Portable Document Scan- ner Each context has (at least) one unique identification within the management domain. The same item of management information can exist in multiple contexts. An item of management information may have http://www.javvin.com/portablescan- multiple unique identifications. This occurs when an item of management information exists in multiple ner.html contexts, and this also occurs when a context has multiple unique identifications. www.javvin.com The combination of a contextEngineID and a contextName unambiguously identifies a context within an www.networkdictionary. administrative domain; note that there may be multiple unique combinations of contextEngineID and con- com textName that unambiguously identify the same context. [ Page 9 ]
    • Architecture for SNMP Management Frameworks December 2002 Network Dictionary 3.3.2. contextEngineID http://www.javvin.com/networkdiction- ary.html Within an administrative domain, a contextEngineID uniquely identifies an SNMP entity that may realize Network Protocols Map an instance of a context with a particular contextName. http://www.javvin.com/map.html 3.3.3. contextName Network Security Map http://www.javvin.com/securitymap. A contextName is used to name a context. Each contextName MUST be unique within an SNMP entity. html Wireless Communications 3.3.4. scopedPDU Technology Map http://www.javvin.com/wirelessmap. A scopedPDU is a block of data containing a contextEngineID, a contextName, and a PDU. html Network Protocols Hand- The PDU is an SNMP Protocol Data Unit containing information named in the context which is unam- book biguously identified within an administrative domain by the combination of the contextEngineID and the contextName. See, for example, RFC 346 for more information about SNMP PDUs. http://www.javvin.com/model.html TCP/IP Quick Guide 3.4. Other Constructs http://www.javvin.com/tcpipguide.html 3.4.1. maxSizeResponseScopedPDU Ethernet Quick Guide http://www.javvin.com/ethernetguide. The maxSizeResponseScopedPDU is the maximum size of a scopedPDU that a PDU's sender would be html willing to accept. Note that the size of a scopedPDU does not include the size of the SNMP message header. Packet Analyzer http://www.javvin.com/packet.html 3.4.2. Local Configuration Datastore DiskShare The subsystems, models, and applications within an SNMP entity may need to retain their own sets of http://www.javvin.com/diskshare.html configuration information. DiskAccess Portions of the configuration information may be accessible as managed objects. http://www.javvin.com/diskaccess.html The collection of these sets of information is referred to as an entity's Local Configuration Datastore LANsurveyor (LCD). http://www.javvin.com/LANsurveyor. 3.4.3. securityLevel html CyberGauge This architecture recognizes three levels of security: http://www.javvin.com/CyberGauge. html - without authentication and without privacy (noAuthNoPriv) Easy Network Service - with authentication but without privacy (authNoPriv) Monitor - with authentication and with privacy (authPriv) http://www.javvin.com/easy.html Business Card Scanner These three values are ordered such that noAuthNoPriv is less than authNoPriv and authNoPriv is less than http://www.javvin.com/businesscard- authPriv. scanner.html Color Cards and Picture Every message has an associated securityLevel. All Subsystems (Message Processing, Security, Access Control) and applications are REQUIRED to either supply a value of securityLevel or to abide by the sup- Scanner plied value of securityLevel while processing the message and its contents. http://www.javvin.com/colorcardscan- ner.html 4. Abstract Service Interfaces Portable Document Scan- ner Abstract service interfaces have been defined to describe the conceptual interfaces between the various sub- http://www.javvin.com/portablescan- systems within an SNMP entity. The abstract service interfaces are intended to help clarify the externally ner.html observable behavior of SNMP entities, and are not intended to constrain the structure or organization of www.javvin.com implementations in any way. Most specifically, they should not be interpreted as APIs or as requirements statements for APIs. www.networkdictionary. com These abstract service interfaces are defined by a set of primitives that define the services provided and the [ Page 20 ]
    • Architecture for SNMP Management Frameworks December 2002 Network Dictionary abstract data elements that are to be passed when the services are invoked. This section lists the primitives that have been defined for the various subsystems. http://www.javvin.com/networkdiction- ary.html 4.1. Dispatcher Primitives Network Protocols Map http://www.javvin.com/map.html The Dispatcher typically provides services to the SNMP applications via its PDU Dispatcher. This section describes the primitives provided by the PDU Dispatcher. Network Security Map http://www.javvin.com/securitymap. 4.1.1. Generate Outgoing Request or Notification html Wireless Communications The PDU Dispatcher provides the following primitive for an application to send an SNMP Request or Technology Map Notification to another SNMP entity: http://www.javvin.com/wirelessmap. statusInformation = -- sendPduHandle if success html -- errorIndication if failure Network Protocols Hand- sendPdu( book IN transportDomain -- transport domain to be used http://www.javvin.com/model.html IN transportAddress -- transport address to be used IN messageProcessingModel -- typically, SNMP version TCP/IP Quick Guide IN securityModel -- Security Model to use http://www.javvin.com/tcpipguide.html IN securityName -- on behalf of this principal IN securityLevel -- Level of Security requested IN contextEngineID -- data from/at this entity Ethernet Quick Guide IN contextName -- data from/in this context http://www.javvin.com/ethernetguide. IN pduVersion -- the version of the PDU html IN PDU -- SNMP Protocol Data Unit IN expectResponse -- TRUE or FALSE Packet Analyzer ) http://www.javvin.com/packet.html 4.1.2. Process Incoming Request or Notification PDU DiskShare http://www.javvin.com/diskshare.html The PDU Dispatcher provides the following primitive to pass an incoming SNMP PDU to an application: DiskAccess processPdu( -- process Request/Notification PDU http://www.javvin.com/diskaccess.html IN messageProcessingModel -- typically, SNMP version IN securityModel -- Security Model in use LANsurveyor IN securityName -- on behalf of this principal http://www.javvin.com/LANsurveyor. IN securityLevel -- Level of Security html IN contextEngineID -- data from/at this SNMP entity IN contextName -- data from/in this context CyberGauge IN pduVersion -- the version of the PDU http://www.javvin.com/CyberGauge. IN PDU -- SNMP Protocol Data Unit html IN maxSizeResponseScopedPDU -- maximum size of the Response PDU IN stateReference -- reference to state information Easy Network Service ) -- needed when sending a response Monitor 4.1.3. Generate Outgoing Response http://www.javvin.com/easy.html Business Card Scanner The PDU Dispatcher provides the following primitive for an application to return an SNMP Response PDU http://www.javvin.com/businesscard- to the PDU Dispatcher: scanner.html Color Cards and Picture result = -- SUCCESS or FAILURE Scanner returnResponsePdu( IN messageProcessingModel -- typically, SNMP version http://www.javvin.com/colorcardscan- IN securityModel -- Security Model in use ner.html IN securityName -- on behalf of this principal Portable Document Scan- IN securityLevel -- same as on incoming request ner IN contextEngineID -- data from/at this SNMP entity http://www.javvin.com/portablescan- IN contextName -- data from/in this context ner.html IN pduVersion -- the version of the PDU www.javvin.com IN PDU -- SNMP Protocol Data Unit IN maxSizeResponseScopedPDU -- maximum size sender can accept IN stateReference -- reference to state information www.networkdictionary. -- as presented with the request com [ Page 2 ]
    • Architecture for SNMP Management Frameworks December 2002 Network Dictionary IN statusInformation -- success or errorIndication ) -- error counter OID/value if error http://www.javvin.com/networkdiction- ary.html 4.1.4. Process Incoming Response PDU Network Protocols Map http://www.javvin.com/map.html The PDU Dispatcher provides the following primitive to pass an incoming SNMP Response PDU to an application: Network Security Map processResponsePdu( -- process Response PDU http://www.javvin.com/securitymap. IN messageProcessingModel -- typically, SNMP version html IN securityModel -- Security Model in use Wireless Communications IN securityName -- on behalf of this principal Technology Map IN securityLevel -- Level of Security http://www.javvin.com/wirelessmap. IN contextEngineID -- data from/at this SNMP entity html IN contextName -- data from/in this context Network Protocols Hand- IN pduVersion -- the version of the PDU IN PDU -- SNMP Protocol Data Unit book IN statusInformation -- success or errorIndication http://www.javvin.com/model.html IN sendPduHandle -- handle from sendPdu TCP/IP Quick Guide ) http://www.javvin.com/tcpipguide.html 4.1.5. Registering Responsibility for Handling SNMP PDUs Ethernet Quick Guide Applications can register/unregister responsibility for a specific contextEngineID, for specific pduTypes, http://www.javvin.com/ethernetguide. with the PDU Dispatcher according to the following primitives. The list of particular pduTypes that an ap- html plication can register for is determined by the Message Processing Model(s) supported by the SNMP entity that contains the PDU Dispatcher. Packet Analyzer http://www.javvin.com/packet.html statusInformation = -- success or errorIndication registerContextEngineID( DiskShare IN contextEngineID -- take responsibility for this one http://www.javvin.com/diskshare.html IN pduType -- the pduType(s) to be registered ) DiskAccess unregisterContextEngineID( http://www.javvin.com/diskaccess.html IN contextEngineID -- give up responsibility for this one IN pduType -- the pduType(s) to be unregistered LANsurveyor ) http://www.javvin.com/LANsurveyor. html Note that realizations of the registerContextEngineID and unregisterContextEngineID abstract service in- terfaces may provide implementation-specific ways for applications to register/deregister responsibility for CyberGauge all possible values of the contextEngineID or pduType parameters. http://www.javvin.com/CyberGauge. html 4.2. Message Processing Subsystem Primitives Easy Network Service Monitor The Dispatcher interacts with a Message Processing Model to process a specific version of an SNMP Mes- sage. This section describes the primitives provided by the Message Processing Subsystem. http://www.javvin.com/easy.html Business Card Scanner 4.2.1. Prepare Outgoing SNMP Request or Notification Message http://www.javvin.com/businesscard- scanner.html The Message Processing Subsystem provides this service primitive for preparing an outgoing SNMP Re- Color Cards and Picture quest or Notification Message: Scanner statusInformation = -- success or errorIndication http://www.javvin.com/colorcardscan- prepareOutgoingMessage( ner.html IN transportDomain -- transport domain to be used Portable Document Scan- IN transportAddress -- transport address to be used ner IN messageProcessingModel -- typically, SNMP version http://www.javvin.com/portablescan- IN securityModel -- Security Model to use ner.html IN securityName -- on behalf of this principal www.javvin.com IN securityLevel -- Level of Security requested IN contextEngineID -- data from/at this entity IN contextName -- data from/in this context www.networkdictionary. IN pduVersion -- the version of the PDU com [ Page 22 ]
    • Architecture for SNMP Management Frameworks December 2002 Network Dictionary IN PDU -- SNMP Protocol Data Unit IN expectResponse -- TRUE or FALSE http://www.javvin.com/networkdiction- IN sendPduHandle -- the handle for matching ary.html -- incoming responses Network Protocols Map OUT destTransportDomain -- destination transport domain OUT destTransportAddress -- destination transport address http://www.javvin.com/map.html OUT outgoingMessage -- the message to send OUT outgoingMessageLength -- its length Network Security Map ) http://www.javvin.com/securitymap. html 4.2.2. Prepare an Outgoing SNMP Response Message Wireless Communications Technology Map The Message Processing Subsystem provides this service primitive for preparing an outgoing SNMP Re- http://www.javvin.com/wirelessmap. sponse Message: html Network Protocols Hand- result = -- SUCCESS or FAILURE prepareResponseMessage( book IN messageProcessingModel -- typically, SNMP version http://www.javvin.com/model.html IN securityModel -- same as on incoming request TCP/IP Quick Guide IN securityName -- same as on incoming request IN securityLevel -- same as on incoming request http://www.javvin.com/tcpipguide.html IN contextEngineID -- data from/at this SNMP entity IN contextName -- data from/in this context Ethernet Quick Guide IN pduVersion -- the version of the PDU IN PDU -- SNMP Protocol Data Unit http://www.javvin.com/ethernetguide. IN maxSizeResponseScopedPDU -- maximum size able to accept html IN stateReference -- reference to state information Packet Analyzer -- as presented with the request IN statusInformation -- success or errorIndication http://www.javvin.com/packet.html -- error counter OID/value if error OUT destTransportDomain -- destination transport domain DiskShare OUT destTransportAddress -- destination transport address http://www.javvin.com/diskshare.html OUT outgoingMessage -- the message to send OUT outgoingMessageLength -- its length DiskAccess ) http://www.javvin.com/diskaccess.html 4.2.3. Prepare Data Elements from an Incoming SNMP Mes- LANsurveyor sage http://www.javvin.com/LANsurveyor. html The Message Processing Subsystem provides this service primitive for preparing the abstract data elements CyberGauge from an incoming SNMP message: http://www.javvin.com/CyberGauge. html result = -- SUCCESS or errorIndication prepareDataElements( Easy Network Service IN transportDomain -- origin transport domain Monitor IN transportAddress -- origin transport address IN wholeMsg -- as received from the network http://www.javvin.com/easy.html IN wholeMsgLength -- as received from the network Business Card Scanner OUT messageProcessingModel -- typically, SNMP version http://www.javvin.com/businesscard- OUT securityModel -- Security Model to use scanner.html OUT securityName -- on behalf of this principal Color Cards and Picture OUT securityLevel -- Level of Security requested OUT contextEngineID -- data from/at this entity Scanner OUT contextName -- data from/in this context http://www.javvin.com/colorcardscan- OUT pduVersion -- the version of the PDU ner.html OUT PDU -- SNMP Protocol Data Unit Portable Document Scan- OUT pduType -- SNMP PDU type ner OUT sendPduHandle -- handle for matched request OUT maxSizeResponseScopedPDU -- maximum size sender can accept http://www.javvin.com/portablescan- OUT statusInformation -- success or errorIndication ner.html -- error counter OID/value if error www.javvin.com OUT stateReference -- reference to state information -- to be used for possible Response www.networkdictionary. ) com [ Page 23 ]
    • Architecture for SNMP Management Frameworks December 2002 4.3. Access Control Subsystem Primitives Network Dictionary http://www.javvin.com/networkdiction- ary.html Applications are the typical clients of the service(s) of the Access Control Subsystem. Network Protocols Map The following primitive is provided by the Access Control Subsystem to check if access is allowed: http://www.javvin.com/map.html statusInformation = -- success or errorIndication Network Security Map isAccessAllowed( IN securityModel -- Security Model in use http://www.javvin.com/securitymap. IN securityName -- principal who wants to access html IN securityLevel -- Level of Security Wireless Communications IN viewType -- read, write, or notify view Technology Map IN contextName -- context containing variableName http://www.javvin.com/wirelessmap. IN variableName -- OID for the managed object html ) Network Protocols Hand- 4.4. Security Subsystem Primitives book http://www.javvin.com/model.html The Message Processing Subsystem is the typical client of the services of the Security Subsystem. TCP/IP Quick Guide http://www.javvin.com/tcpipguide.html 4.4.1. Generate a Request or Notification Message Ethernet Quick Guide The Security Subsystem provides the following primitive to generate a Request or Notification message: http://www.javvin.com/ethernetguide. statusInformation = html generateRequestMsg( Packet Analyzer IN messageProcessingModel -- typically, SNMP version IN globalData -- message header, admin data http://www.javvin.com/packet.html IN maxMessageSize -- of the sending SNMP entity IN securityModel -- for the outgoing message DiskShare IN securityEngineID -- authoritative SNMP entity http://www.javvin.com/diskshare.html IN securityName -- on behalf of this principal IN securityLevel -- Level of Security requested DiskAccess IN scopedPDU -- message (plaintext) payload http://www.javvin.com/diskaccess.html OUT securityParameters -- filled in by Security Module OUT wholeMsg -- complete generated message LANsurveyor OUT wholeMsgLength -- length of the generated message ) http://www.javvin.com/LANsurveyor. html 4.4.2. Process Incoming Message CyberGauge http://www.javvin.com/CyberGauge. The Security Subsystem provides the following primitive to process an incoming message: html statusInformation = -- errorIndication or success Easy Network Service -- error counter OID/value if error Monitor processIncomingMsg( http://www.javvin.com/easy.html IN messageProcessingModel -- typically, SNMP version IN maxMessageSize -- of the sending SNMP entity Business Card Scanner IN securityParameters -- for the received message http://www.javvin.com/businesscard- IN securityModel -- for the received message scanner.html IN securityLevel -- Level of Security Color Cards and Picture IN wholeMsg -- as received on the wire Scanner IN wholeMsgLength -- length as received on the wire OUT securityEngineID -- authoritative SNMP entity http://www.javvin.com/colorcardscan- OUT securityName -- identification of the principal ner.html OUT scopedPDU, -- message (plaintext) payload Portable Document Scan- OUT maxSizeResponseScopedPDU -- maximum size sender can handle ner OUT securityStateReference -- reference to security state http://www.javvin.com/portablescan- ) -- information, needed for response ner.html www.javvin.com 4.4.3. Generate a Response Message www.networkdictionary. The Security Subsystem provides the following primitive to generate a Response message: com [ Page 24 ]
    • Architecture for SNMP Management Frameworks December 2002 Network Dictionary statusInformation = generateResponseMsg( http://www.javvin.com/networkdiction- IN messageProcessingModel -- typically, SNMP version ary.html IN globalData -- message header, admin data Network Protocols Map IN maxMessageSize -- of the sending SNMP entity IN securityModel -- for the outgoing message http://www.javvin.com/map.html IN securityEngineID -- authoritative SNMP entity IN securityName -- on behalf of this principal Network Security Map IN securityLevel -- for the outgoing message http://www.javvin.com/securitymap. IN scopedPDU -- message (plaintext) payload html IN securityStateReference -- reference to security state Wireless Communications -- information from original request Technology Map OUT securityParameters -- filled in by Security Module OUT wholeMsg -- complete generated message http://www.javvin.com/wirelessmap. OUT wholeMsgLength -- length of the generated message html ) Network Protocols Hand- book 4.5. Common Primitives http://www.javvin.com/model.html TCP/IP Quick Guide These primitive(s) are provided by multiple Subsystems. http://www.javvin.com/tcpipguide.html 4.5.1. Release State Reference Information Ethernet Quick Guide All Subsystems which pass stateReference information also provide a primitive to release the memory that http://www.javvin.com/ethernetguide. holds the referenced state information: html stateRelease( Packet Analyzer IN stateReference -- handle of reference to be released http://www.javvin.com/packet.html ) DiskShare 4.6. Scenario Diagrams http://www.javvin.com/diskshare.html 4.6.1. Command Generator or Notification Originator DiskAccess http://www.javvin.com/diskaccess.html This diagram shows how a Command Generator or Notification Originator application requests that a PDU be sent, and how the response is returned (asynchronously) to that application. LANsurveyor http://www.javvin.com/LANsurveyor. html CyberGauge http://www.javvin.com/CyberGauge. html Easy Network Service Monitor http://www.javvin.com/easy.html Business Card Scanner http://www.javvin.com/businesscard- scanner.html Color Cards and Picture Scanner http://www.javvin.com/colorcardscan- ner.html Portable Document Scan- ner http://www.javvin.com/portablescan- ner.html www.javvin.com www.networkdictionary. com [ Page 25 ]
    • Architecture for SNMP Management Frameworks December 2002 Network Dictionary http://www.javvin.com/networkdiction- ary.html Network Protocols Map http://www.javvin.com/map.html Network Security Map http://www.javvin.com/securitymap. html Wireless Communications Technology Map http://www.javvin.com/wirelessmap. html Network Protocols Hand- book http://www.javvin.com/model.html TCP/IP Quick Guide http://www.javvin.com/tcpipguide.html Ethernet Quick Guide http://www.javvin.com/ethernetguide. html Packet Analyzer http://www.javvin.com/packet.html DiskShare http://www.javvin.com/diskshare.html DiskAccess 4.6.2. Scenario Diagram for a Command Responder Applica- http://www.javvin.com/diskaccess.html tion LANsurveyor This diagram shows how a Command Responder or Notification Receiver application registers for han- http://www.javvin.com/LANsurveyor. dling a pduType, how a PDU is dispatched to the application after an SNMP message is received, and how html the Response is (asynchronously) send back to the network. CyberGauge http://www.javvin.com/CyberGauge. html Easy Network Service Monitor http://www.javvin.com/easy.html Business Card Scanner http://www.javvin.com/businesscard- scanner.html Color Cards and Picture Scanner http://www.javvin.com/colorcardscan- ner.html Portable Document Scan- ner http://www.javvin.com/portablescan- ner.html www.javvin.com www.networkdictionary. com [ Page 26 ]
    • Architecture for SNMP Management Frameworks December 2002 Network Dictionary http://www.javvin.com/networkdiction- ary.html Network Protocols Map http://www.javvin.com/map.html Network Security Map http://www.javvin.com/securitymap. html Wireless Communications Technology Map http://www.javvin.com/wirelessmap. html Network Protocols Hand- book http://www.javvin.com/model.html TCP/IP Quick Guide http://www.javvin.com/tcpipguide.html Ethernet Quick Guide http://www.javvin.com/ethernetguide. html Packet Analyzer http://www.javvin.com/packet.html DiskShare http://www.javvin.com/diskshare.html DiskAccess http://www.javvin.com/diskaccess.html 5. Managed Object Definitions for SNMP Man- LANsurveyor agement Frameworks http://www.javvin.com/LANsurveyor. html SNMP-FRAMEWORK-MIB DEFINITIONS ::= BEGIN CyberGauge http://www.javvin.com/CyberGauge. IMPORTS html MODULE-IDENTITY, OBJECT-TYPE, OBJECT-IDENTITY, Easy Network Service snmpModules FROM SNMPv2-SMI Monitor TEXTUAL-CONVENTION FROM SNMPv2-TC MODULE-COMPLIANCE, OBJECT-GROUP FROM SNMPv2-CONF; http://www.javvin.com/easy.html Business Card Scanner snmpFrameworkMIB MODULE-IDENTITY http://www.javvin.com/businesscard- LAST-UPDATED quot;2002040000Zquot; scanner.html ORGANIZATION quot;SNMPv3 Working Groupquot; Color Cards and Picture CONTACT-INFO quot;WG-EMail: snmpv3@lists.tislabs.com Subscribe: snmpv3-request@lists.tislabs.com Scanner http://www.javvin.com/colorcardscan- Co-Chair: Russ Mundy ner.html Network Associates Laboratories Portable Document Scan- postal: 5204 Omega Drive, Suite 300 ner Rockville, MD 20850-460 USA http://www.javvin.com/portablescan- EMail: mundy@tislabs.com ner.html phone: + 30-947-707 www.javvin.com Co-Chair & www.networkdictionary. Co-editor: David Harrington com Enterasys Networks [ Page 27 ]
    • Architecture for SNMP Management Frameworks December 2002 Network Dictionary postal: 35 Industrial Way P. O. Box 5005 http://www.javvin.com/networkdiction- Rochester, New Hampshire 03866-5005 ary.html USA Network Protocols Map EMail: dbh@enterasys.com phone: + 603-337-264 http://www.javvin.com/map.html Co-editor: Randy Presuhn Network Security Map BMC Software, Inc. http://www.javvin.com/securitymap. postal: 24 North First Street html San Jose, California 953 Wireless Communications USA Technology Map EMail: randy_presuhn@bmc.com phone: + 408-546-006 http://www.javvin.com/wirelessmap. html Co-editor: Bert Wijnen Network Protocols Hand- Lucent Technologies book postal: Schagen 33 http://www.javvin.com/model.html 346 GL Linschoten Netherlands TCP/IP Quick Guide EMail: bwijnen@lucent.com http://www.javvin.com/tcpipguide.html phone: +3 348-680-485 quot; DESCRIPTION quot;The SNMP Management Architecture MIB Ethernet Quick Guide http://www.javvin.com/ethernetguide. Copyright (C) The Internet Society (2002). This html version of this MIB module is part of RFC 34; see the RFC itself for full legal notices. Packet Analyzer quot; http://www.javvin.com/packet.html REVISION quot;2002040000Zquot; -- 4 October 2002 DiskShare DESCRIPTION quot;Changes in this revision: http://www.javvin.com/diskshare.html - Updated various administrative information. - Corrected some typos. DiskAccess - Corrected typo in description of SnmpEngineID that led to range overlap for 27. http://www.javvin.com/diskaccess.html - Changed '255a' to '255t' in definition of SnmpAdminString to align with current SMI. LANsurveyor - Reworded 'reserved' for value zero in http://www.javvin.com/LANsurveyor. DESCRIPTION of SnmpSecurityModel. html - The algorithm for allocating security models should give 256 per enterprise block, rather CyberGauge than 255. http://www.javvin.com/CyberGauge. - The example engine ID of 'abcd' is not html legal. Replaced with '800002b80466263'H based on example enterprise 696, string 'abc'. Easy Network Service - Added clarification that engineID should Monitor persist across re-initializations. http://www.javvin.com/easy.html This revision published as RFC 34. quot; Business Card Scanner REVISION quot;999090000Zquot; -- 9 January 999 http://www.javvin.com/businesscard- DESCRIPTION quot;Updated editors' addresses, fixed typos. scanner.html Published as RFC 257. Color Cards and Picture quot; Scanner REVISION quot;997200000Zquot; -- 20 November 997 DESCRIPTION quot;The initial version, published in RFC 227. http://www.javvin.com/colorcardscan- quot; ner.html ::= { snmpModules 0 } Portable Document Scan- ner -- Textual Conventions used in the SNMP Management Architecture *** http://www.javvin.com/portablescan- ner.html SnmpEngineID ::= TEXTUAL-CONVENTION www.javvin.com STATUS current DESCRIPTION quot;An SNMP engine's administratively-unique identifier. Objects of this type are for identification, not for addressing, even though it is possible www.networkdictionary. that an address may have been used in the generation of a specific value. com [ Page 28 ]
    • Architecture for SNMP Management Frameworks December 2002 Network Dictionary The value for this object may not be all zeros or all 'ff'H or the empty (zero length) string. http://www.javvin.com/networkdiction- ary.html The initial value for this object may be configured via an operator console entry or via Network Protocols Map an algorithmic function. In the latter case, the following example algorithm is recom- mended. http://www.javvin.com/map.html In cases where there are multiple engines on the same system, the use of this algorithm Network Security Map is NOT appropriate, as it would result in all of those engines ending up with the same http://www.javvin.com/securitymap. ID value. html Wireless Communications 1) The very first bit is used to indicate how the rest of the data is composed. Technology Map 0 - as defined by enterprise using former methods that existed before SNMPv3. See http://www.javvin.com/wirelessmap. item 2 below. html Network Protocols Hand- 1 - as defined by this architecture, see item 3 below. book http://www.javvin.com/model.html Note that this allows existing uses of the engineID (also known as AgentID [RFC90]) to co-exist with any new uses. TCP/IP Quick Guide http://www.javvin.com/tcpipguide.html 2) The snmpEngineID has a length of 2 octets. The first four octets are set to the binary equivalent of the agent's SNMP management Ethernet Quick Guide private enterprise number as assigned by the Internet Assigned Numbers Authority http://www.javvin.com/ethernetguide. (IANA). For example, if Acme Networks has been assigned { enterprises 696 }, the html first four octets would be assigned '000002b8'H. Packet Analyzer The remaining eight octets are determined via one or more enterprise-specific methods. http://www.javvin.com/packet.html Such methods must be designed so as to maximize the possibility that the value of this object will be unique in the agent's administrative domain. For example, it may be the DiskShare IP address of the SNMP entity, or the MAC address of one of the interfaces, with each http://www.javvin.com/diskshare.html address suitably padded with random octets. If multiple methods are defined, then it is recommended that the first octet indicate the method being used and the remaining DiskAccess octets be a function of the method. http://www.javvin.com/diskaccess.html 3) The length of the octet string varies. LANsurveyor The first four octets are set to the binary equivalent of the agent's SNMP management http://www.javvin.com/LANsurveyor. private enterprise number as assigned by the Internet Assigned Numbers Authority html (IANA). For example, if Acme Networks has been assigned { enterprises 696 }, the first four octets would be assigned '000002b8'H. CyberGauge http://www.javvin.com/CyberGauge. The very first bit is set to 1. For example, the above value for Acme Networks now html changes to be Easy Network Service '800002b8'H. Monitor http://www.javvin.com/easy.html The fifth octet indicates how the rest (6th and following octets) are formatted. The values for the fifth octet are: Business Card Scanner http://www.javvin.com/businesscard- 0 - reserved, unused. scanner.html Color Cards and Picture  - IPv4 address (4 octets) lowest non-special IP address Scanner 2 - IPv6 address (6 octets) lowest non-special IP address http://www.javvin.com/colorcardscan- ner.html 3 - MAC address (6 octets) lowest IEEE MAC address, canonical order Portable Document Scan- ner 4 - Text, administratively assigned Maximum remaining length 27 http://www.javvin.com/portablescan- ner.html 5 - Octets, administratively assigned Maximum remaining length 27 www.javvin.com 6-27 - reserved, unused www.networkdictionary. 128-255 - as defined by the enterprise Maximum remaining length 27 com [ Page 29 ]
    • Architecture for SNMP Management Frameworks December 2002 Network Dictionary quot; SYNTAX OCTET STRING (SIZE(5..32)) http://www.javvin.com/networkdiction- ary.html SnmpSecurityModel ::= TEXTUAL-CONVENTION Network Protocols Map STATUS current DESCRIPTION quot;An identifier that uniquely identifies a http://www.javvin.com/map.html Security Model of the Security Subsystem within this SNMP Management Architec- ture. Network Security Map http://www.javvin.com/securitymap. The values for securityModel are allocated as follows: html Wireless Communications - The zero value does not identify any particular security model. Technology Map - Values between  and 255, inclusive, are reserved for standards-track Security Mod- http://www.javvin.com/wirelessmap. els and are managed by the Internet Assigned Numbers Authority (IANA). html - Values greater than 255 are allocated to enterprise-specific Security Models. An en- Network Protocols Hand- terprise-specific securityModel value is defined to be: book http://www.javvin.com/model.html enterpriseID * 256 + security model within enterprise TCP/IP Quick Guide For example, the fourth Security Model defined by the enterprise whose enterpriseID http://www.javvin.com/tcpipguide.html is  would be 259. This scheme for allocation of securityModel values allows for a maximum of 255 Ethernet Quick Guide standards- based Security Models, and for a maximum of 256 Security Models per http://www.javvin.com/ethernetguide. enterprise. html It is believed that the assignment of new securityModel values will be rare in practice Packet Analyzer because the larger the number of simultaneously utilized Security Models, the larger http://www.javvin.com/packet.html the chance that interoperability will suffer. Consequently, it is believed that such a range will be sufficient. In the unlikely event that the standards committee finds this DiskShare number to be insufficient over time, an enterprise number can be allocated to obtain an http://www.javvin.com/diskshare.html additional 256 possible values. DiskAccess Note that the most significant bit must be zero; hence, there are 23 bits allocated for various organizations to design and define non-standard securityModels. This limits http://www.javvin.com/diskaccess.html the ability to define new proprietary implementations of Security Models to the first 8,388,608 enterprises. LANsurveyor http://www.javvin.com/LANsurveyor. It is worthwhile to note that, in its encoded form, the securityModel value will nor- html mally require only a single byte since, in practice, the leftmost bits will be zero for most messages and sign extension is suppressed by the encoding rules. CyberGauge http://www.javvin.com/CyberGauge. As of this writing, there are several values of securityModel defined for use with SNMP html or reserved for use with supporting MIB objects. They are as follows: Easy Network Service 0 reserved for 'any' Monitor  reserved for SNMPv http://www.javvin.com/easy.html 2 reserved for SNMPv2c 3 User-Based Security Model (USM) Business Card Scanner quot; http://www.javvin.com/businesscard- SYNTAX INTEGER(0 .. 247483647) scanner.html Color Cards and Picture Scanner SnmpMessageProcessingModel ::= TEXTUAL-CONVENTION STATUS current http://www.javvin.com/colorcardscan- DESCRIPTION quot;An identifier that uniquely identifies a Message ner.html Processing Model of the Message Processing Subsystem within this SNMP Manage- Portable Document Scan- ment Architecture. ner http://www.javvin.com/portablescan- The values for messageProcessingModel are allocated as follows: ner.html www.javvin.com - Values between 0 and 255, inclusive, are reserved for standards-track Message Processing Models and are managed by the Internet Assigned Numbers Authority (IANA). www.networkdictionary. com - Values greater than 255 are allocated to enterprise-specific Message Processing Mod- [ Page 30 ]
    • Architecture for SNMP Management Frameworks December 2002 Network Dictionary els. An enterprise messageProcessingModel value is defined to be: http://www.javvin.com/networkdiction- enterpriseID * 256 + ary.html messageProcessingModel within enterprise Network Protocols Map For example, the fourth Message Processing Model defined by the enterprise whose http://www.javvin.com/map.html enterpriseID is  would be 259. Network Security Map This scheme for allocating messageProcessingModel values allows for a maximum of http://www.javvin.com/securitymap. 255 standards- based Message Processing Models, and for a maximum of 256 Message html Processing Models per enterprise. Wireless Communications Technology Map It is believed that the assignment of new messageProcessingModel values will be rare in practice because the larger the number of simultaneously utilized Message Process- http://www.javvin.com/wirelessmap. ing Models, the larger the chance that interoperability will suffer. It is believed that html such a range will be sufficient. In the unlikely event that the standards committee finds Network Protocols Hand- this number to be insufficient over time, an enterprise number can be allocated to ob- book tain an additional 256 possible values. http://www.javvin.com/model.html Note that the most significant bit must be zero; hence, there are 23 bits allocated for TCP/IP Quick Guide various organizations to design and define non-standard messageProcessingModels. http://www.javvin.com/tcpipguide.html This limits the ability to define new proprietary implementations of Message Process- ing Models to the first 8,388,608 enterprises. Ethernet Quick Guide It is worthwhile to note that, in its encoded form, the messageProcessingModel value http://www.javvin.com/ethernetguide. will normally require only a single byte since, in practice, the leftmost bits will be zero html for most messages and sign extension is suppressed by the encoding rules. Packet Analyzer As of this writing, there are several values of messageProcessingModel defined for use http://www.javvin.com/packet.html with SNMP. They are as follows: DiskShare 0 reserved for SNMPv http://www.javvin.com/diskshare.html  reserved for SNMPv2c 2 reserved for SNMPv2u and SNMPv2* DiskAccess 3 reserved for SNMPv3 quot; http://www.javvin.com/diskaccess.html SYNTAX INTEGER(0 .. 247483647) LANsurveyor SnmpSecurityLevel ::= TEXTUAL-CONVENTION http://www.javvin.com/LANsurveyor. STATUS current html DESCRIPTION quot;A Level of Security at which SNMP messages can be sent or with which operations are being processed; in particular, one of: CyberGauge http://www.javvin.com/CyberGauge. noAuthNoPriv - without authentication and without privacy, html authNoPriv - with authentication but without privacy, authPriv - with authentication and with privacy. Easy Network Service Monitor These three values are ordered such that noAuthNoPriv is less than authNoPriv and http://www.javvin.com/easy.html authNoPriv is less than authPriv. quot; Business Card Scanner SYNTAX INTEGER { noAuthNoPriv(), http://www.javvin.com/businesscard- authNoPriv(2), scanner.html authPriv(3) Color Cards and Picture } Scanner SnmpAdminString ::= TEXTUAL-CONVENTION http://www.javvin.com/colorcardscan- DISPLAY-HINT quot;255tquot; ner.html STATUS current Portable Document Scan- DESCRIPTION quot;An octet string containing administrative ner information, preferably in human-readable form. http://www.javvin.com/portablescan- ner.html To facilitate internationalization, this information is represented using the ISO/IEC www.javvin.com IS 0646- character set, encoded as an octet string using the UTF-8 transformation format described in [RFC2279]. www.networkdictionary. Since additional code points are added by amendments to the 0646 standard from com time to time, implementations must be prepared to encounter any code point from [ Page 3 ]
    • Architecture for SNMP Management Frameworks December 2002 Network Dictionary 0x00000000 to 0x7fffffff. Byte sequences that do not correspond to the valid UTF-8 encoding of a code point or are outside this range are prohibited. http://www.javvin.com/networkdiction- ary.html The use of control codes should be avoided. Network Protocols Map When it is necessary to represent a newline, the control code sequence CR LF should http://www.javvin.com/map.html be used. The use of leading or trailing white space should be avoided. Network Security Map For code points not directly supported by user interface hardware or software, an alter- http://www.javvin.com/securitymap. native means of entry and display, such as hexadecimal, may be provided. html Wireless Communications For information encoded in 7-bit US-ASCII, the UTF-8 encoding is identical to the Technology Map US-ASCII encoding. http://www.javvin.com/wirelessmap. UTF-8 may require multiple bytes to represent a single character / code point; thus the html length of this object in octets may be different from the number of characters encoded. Network Protocols Hand- Similarly, size constraints refer to the number of encoded octets, not the number of book characters represented by an encoding. http://www.javvin.com/model.html Note that when this TC is used for an object that is used or envisioned to be used as an TCP/IP Quick Guide index, then a SIZE restriction MUST be specified so that the number of sub-identifiers http://www.javvin.com/tcpipguide.html for any object instance does not exceed the limit of 128, as defined by [RFC3416]. Note that the size of an SnmpAdminString object is measured in octets, not charac- Ethernet Quick Guide ters. http://www.javvin.com/ethernetguide. quot; html SYNTAX OCTET STRING (SIZE (0..255)) Packet Analyzer http://www.javvin.com/packet.html -- Administrative assignments *************************************** DiskShare snmpFrameworkAdmin http://www.javvin.com/diskshare.html OBJECT IDENTIFIER ::= { snmpFrameworkMIB  } snmpFrameworkMIBObjects DiskAccess OBJECT IDENTIFIER ::= { snmpFrameworkMIB 2 } snmpFrameworkMIBConformance http://www.javvin.com/diskaccess.html OBJECT IDENTIFIER ::= { snmpFrameworkMIB 3 } LANsurveyor -- the snmpEngine Group ******************************************** http://www.javvin.com/LANsurveyor. html snmpEngine OBJECT IDENTIFIER ::= { snmpFrameworkMIBObjects  } snmpEngineID OBJECT-TYPE CyberGauge SYNTAX SnmpEngineID http://www.javvin.com/CyberGauge. MAX-ACCESS read-only html STATUS current DESCRIPTION quot;An SNMP engine's administratively-unique identifier. Easy Network Service This information SHOULD be stored in non-volatile storage so that it remains constant Monitor across re-initializations of the SNMP engine. http://www.javvin.com/easy.html quot; ::= { snmpEngine  } Business Card Scanner http://www.javvin.com/businesscard- snmpEngineBoots OBJECT-TYPE scanner.html SYNTAX INTEGER (..247483647) Color Cards and Picture MAX-ACCESS read-only Scanner STATUS current DESCRIPTION quot;The number of times that the SNMP engine has http://www.javvin.com/colorcardscan- (re-)initialized itself since snmpEngineID was last configured. ner.html quot; Portable Document Scan- ::= { snmpEngine 2 } ner http://www.javvin.com/portablescan- snmpEngineTime OBJECT-TYPE ner.html SYNTAX INTEGER (0..247483647) www.javvin.com UNITS quot;secondsquot; MAX-ACCESS read-only STATUS current www.networkdictionary. DESCRIPTION quot;The number of seconds since the value of com the snmpEngineBoots object last changed. When incrementing this object's value [ Page 32 ]
    • Architecture for SNMP Management Frameworks December 2002 Network Dictionary would cause it to exceed its maximum, snmpEngineBoots is incremented as if a re- initialization had occurred, and this object's value consequently reverts to zero. http://www.javvin.com/networkdiction- quot; ary.html ::= { snmpEngine 3 } Network Protocols Map snmpEngineMaxMessageSize OBJECT-TYPE http://www.javvin.com/map.html SYNTAX INTEGER (484..247483647) MAX-ACCESS read-only Network Security Map STATUS current http://www.javvin.com/securitymap. DESCRIPTION quot;The maximum length in octets of an SNMP message html which this SNMP engine can send or receive and process, determined as the minimum Wireless Communications of the maximum message size values supported among all of the transports available Technology Map to and supported by the engine. quot; http://www.javvin.com/wirelessmap. ::= { snmpEngine 4 } html Network Protocols Hand- -- Registration Points for Authentication and Privacy Protocols ** book http://www.javvin.com/model.html snmpAuthProtocols OBJECT-IDENTITY STATUS current TCP/IP Quick Guide DESCRIPTION quot;Registration point for standards-track http://www.javvin.com/tcpipguide.html authentication protocols used in SNMP Management Frameworks. quot; ::= { snmpFrameworkAdmin  } Ethernet Quick Guide http://www.javvin.com/ethernetguide. snmpPrivProtocols OBJECT-IDENTITY html STATUS current DESCRIPTION quot;Registration point for standards-track privacy Packet Analyzer protocols used in SNMP Management Frameworks. http://www.javvin.com/packet.html quot; ::= { snmpFrameworkAdmin 2 } DiskShare http://www.javvin.com/diskshare.html -- Conformance information ****************************************** DiskAccess snmpFrameworkMIBCompliances OBJECT IDENTIFIER ::= {snmpFrameworkMIBConformance } http://www.javvin.com/diskaccess.html snmpFrameworkMIBGroups OBJECT IDENTIFIER ::= {snmpFrameworkMIBConformance 2} LANsurveyor http://www.javvin.com/LANsurveyor. -- compliance statements html snmpFrameworkMIBCompliance MODULE-COMPLIANCE CyberGauge STATUS current http://www.javvin.com/CyberGauge. DESCRIPTION quot;The compliance statement for SNMP engines which html implement the SNMP Management Framework MIB. quot; Easy Network Service MODULE -- this module Monitor MANDATORY-GROUPS { snmpEngineGroup } http://www.javvin.com/easy.html ::= { snmpFrameworkMIBCompliances  } Business Card Scanner http://www.javvin.com/businesscard- -- units of conformance scanner.html Color Cards and Picture snmpEngineGroup OBJECT-GROUP Scanner OBJECTS { snmpEngineID, http://www.javvin.com/colorcardscan- snmpEngineBoots, ner.html snmpEngineTime, Portable Document Scan- snmpEngineMaxMessageSize ner } http://www.javvin.com/portablescan- STATUS current ner.html DESCRIPTION quot;A collection of objects for identifying and www.javvin.com determining the configuration and current timeliness values of an SNMP engine. quot; ::= { snmpFrameworkMIBGroups  } www.networkdictionary. com END [ Page 33 ]
    • Architecture for SNMP Management Frameworks December 2002 Network Dictionary 6. IANA Considerations http://www.javvin.com/networkdiction- ary.html Network Protocols Map This document defines three number spaces administered by IANA, one for security models, another for message processing models, and a third for SnmpEngineID formats. http://www.javvin.com/map.html 6.1. Security Models Network Security Map http://www.javvin.com/securitymap. The SnmpSecurityModel TEXTUAL-CONVENTION values managed by IANA are in the range from 0 to html 255 inclusive, and are reserved for standards-track Security Models. If this range should in the future prove Wireless Communications insufficient, an enterprise number can be allocated to obtain an additional 256 possible values. Technology Map http://www.javvin.com/wirelessmap. As of this writing, there are several values of securityModel defined for use with SNMP or reserved for use html with supporting MIB objects. They are as follows: Network Protocols Hand- 0 reserved for 'any' book  reserved for SNMPv http://www.javvin.com/model.html 2 reserved for SNMPv2c TCP/IP Quick Guide 3 User-Based Security Model (USM) http://www.javvin.com/tcpipguide.html 6.2. Message Processing Models Ethernet Quick Guide The SnmpMessageProcessingModel TEXTUAL-CONVENTION values managed by IANA are in the http://www.javvin.com/ethernetguide. range 0 to 255, inclusive. Each value uniquely identifies a standards-track Message Processing Model of html the Message Processing Subsystem within the SNMP Management Architecture. Packet Analyzer Should this range prove insufficient in the future, an enterprise number may be obtained for the standards http://www.javvin.com/packet.html committee to get an additional 256 possible values. DiskShare As of this writing, there are several values of messageProcessingModel defined for use with SNMP. They http://www.javvin.com/diskshare.html are as follows: DiskAccess 0 reserved for SNMPv  reserved for SNMPv2c http://www.javvin.com/diskaccess.html 2 reserved for SNMPv2u and SNMPv2* 3 reserved for SNMPv3 LANsurveyor http://www.javvin.com/LANsurveyor. 6.3. SnmpEngineID Formats html CyberGauge The SnmpEngineID TEXTUAL-CONVENTION's fifth octet contains a format identifier. The values http://www.javvin.com/CyberGauge. managed by IANA are in the range 6 to 127, inclusive. Each value uniquely identifies a standards-track html SnmpEngineID format. Easy Network Service 7. Intellectual Property Monitor http://www.javvin.com/easy.html The IETF takes no position regarding the validity or scope of any intellectual property or other rights that Business Card Scanner might be claimed to pertain to the implementation or use of the technology described in this document or http://www.javvin.com/businesscard- the extent to which any license under such rights might or might not be available; neither does it represent scanner.html that it has made any effort to identify any such rights. Information on the IETF's procedures with respect Color Cards and Picture to rights in standards-track and standards-related documentation can be found in RFC 2028. Copies of claims of rights made available for publication and any assurances of licenses to be made available, or the Scanner result of an attempt made to obtain a general license or permission for the use of such proprietary rights by http://www.javvin.com/colorcardscan- implementors or users of this specification can be obtained from the IETF Secretariat. ner.html Portable Document Scan- The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, ner or other proprietary rights which may cover technology that may be required to practice this standard. Please address the information to the IETF Executive Director. http://www.javvin.com/portablescan- ner.html 8. Acknowledgements www.javvin.com www.networkdictionary. This document is the result of the efforts of the SNMPv3 Working Group. Some special thanks are in order com to the following SNMPv3 WG members: [ Page 34 ]
    • Architecture for SNMP Management Frameworks December 2002 Network Dictionary Harald Tveit Alvestrand (Maxware) Dave Battle (SNMP Research, Inc.) http://www.javvin.com/networkdiction- Alan Beard (Disney Worldwide Services) ary.html Paul Berrevoets (SWI Systemware/Halcyon Inc.) Network Protocols Map Martin Bjorklund (Ericsson) Uri Blumenthal (IBM T.J. Watson Research Center) http://www.javvin.com/map.html Jeff Case (SNMP Research, Inc.) John Curran (BBN) Network Security Map Mike Daniele (Compaq Computer Corporation) http://www.javvin.com/securitymap. T. Max Devlin (Eltrax Systems) html John Flick (Hewlett Packard) Wireless Communications Rob Frye (MCI) Technology Map Wes Hardaker (U.C.Davis, Information Technology - D.C.A.S.) David Harrington (Cabletron Systems Inc.) http://www.javvin.com/wirelessmap. Lauren Heintz (BMC Software, Inc.) html N.C. Hien (IBM T.J. Watson Research Center) Network Protocols Hand- Michael Kirkham (InterWorking Labs, Inc.) book Dave Levi (SNMP Research, Inc.) http://www.javvin.com/model.html Louis A Mamakos (UUNET Technologies Inc.) Joe Marzot (Nortel Networks) TCP/IP Quick Guide Paul Meyer (Secure Computing Corporation) http://www.javvin.com/tcpipguide.html Keith McCloghrie (Cisco Systems) Bob Moore (IBM) Russ Mundy (TIS Labs at Network Associates) Ethernet Quick Guide Bob Natale (ACE*COMM Corporation) http://www.javvin.com/ethernetguide. Mike O'Dell (UUNET Technologies Inc.) html Dave Perkins (DeskTalk) Peter Polkinghorne (Brunel University) Packet Analyzer Randy Presuhn (BMC Software, Inc.) http://www.javvin.com/packet.html David Reeder (TIS Labs at Network Associates) David Reid (SNMP Research, Inc.) DiskShare Aleksey Romanov (Quality Quorum) http://www.javvin.com/diskshare.html Shawn Routhier (Epilogue) Juergen Schoenwaelder (TU Braunschweig) DiskAccess Bob Stewart (Cisco Systems) Mike Thatcher (Independent Consultant) http://www.javvin.com/diskaccess.html Bert Wijnen (IBM T.J. Watson Research Center) LANsurveyor The document is based on recommendations of the IETF Security and Administrative Framework Evolu- http://www.javvin.com/LANsurveyor. tion for SNMP Advisory Team. Members of that Advisory Team were: html David Harrington (Cabletron Systems Inc.) CyberGauge Jeff Johnson (Cisco Systems) http://www.javvin.com/CyberGauge. David Levi (SNMP Research Inc.) html John Linn (Openvision) Russ Mundy (Trusted Information Systems) chair Easy Network Service Shawn Routhier (Epilogue) Monitor Glenn Waters (Nortel) http://www.javvin.com/easy.html Bert Wijnen (IBM T. J. Watson Research Center) Business Card Scanner As recommended by the Advisory Team and the SNMPv3 Working Group Charter, the design incorporates http://www.javvin.com/businesscard- as much as practical from previous RFCs and drafts. As a result, special thanks are due to the authors of scanner.html previous designs known as SNMPv2u and SNMPv2*: Color Cards and Picture Scanner Jeff Case (SNMP Research, Inc.) David Harrington (Cabletron Systems Inc.) http://www.javvin.com/colorcardscan- David Levi (SNMP Research, Inc.) ner.html Keith McCloghrie (Cisco Systems) Portable Document Scan- Brian O'Keefe (Hewlett Packard) ner Marshall T. Rose (Dover Beach Consulting) http://www.javvin.com/portablescan- Jon Saperia (BGS Systems Inc.) ner.html Steve Waldbusser (International Network Services) www.javvin.com Glenn W. Waters (Bell-Northern Research Ltd.) 9. Security Considerations www.networkdictionary. com [ Page 35 ]
    • Architecture for SNMP Management Frameworks December 2002 Network Dictionary 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. http://www.javvin.com/networkdiction- ary.html The level of security provided is determined by the specific Security Model implementation(s) and the Network Protocols Map specific Access Control Model implementation(s) used. http://www.javvin.com/map.html Applications have access to data which is not secured. Applications SHOULD take reasonable steps to protect the data from disclosure. Network Security Map http://www.javvin.com/securitymap. It is the responsibility of the purchaser of an implementation to ensure that: html Wireless Communications 1) an implementation complies with the rules defined by this architecture, Technology Map 2) the Security and Access Control Models utilized satisfy the security and access control needs of the http://www.javvin.com/wirelessmap. organization, html Network Protocols Hand- 3) the implementations of the Models and Applications comply with the model and application speci- book fications, http://www.javvin.com/model.html 4) and the implementation protects configuration secrets from inadvertent disclosure. TCP/IP Quick Guide http://www.javvin.com/tcpipguide.html This document also contains a MIB definition module. None of the objects defined is writable, and the in- formation they represent is not deemed to be particularly sensitive. However, if they are deemed sensitive in a particular environment, access to them should be restricted through the use of appropriately configured Ethernet Quick Guide Security and Access Control models. http://www.javvin.com/ethernetguide. html 10. References Packet Analyzer http://www.javvin.com/packet.html 10.1. Normative References DiskShare [RFC29] Bradner, S., quot;Key words for use in RFCs to Indicate Requirement Levelsquot;, BCP 4, RFC 29, http://www.javvin.com/diskshare.html March 997. DiskAccess [RFC2279] Yergeau, F., quot;UTF-8, a transformation format of ISO 0646quot;, RFC 2279, January 998. http://www.javvin.com/diskaccess.html [RFC2578] McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J., Rose, M. and S. Waldbusser, quot;Struc- LANsurveyor ture of Management Information Version 2 (SMIv2)quot;, STD 58, RFC 2578, April 999. http://www.javvin.com/LANsurveyor. [RFC2579] McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J., Rose, M. and S. Waldbusser, quot;Textual html Conventions for SMIv2quot;, STD 58, RFC 2579, April 999. CyberGauge [RFC2580] McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J., Rose, M. and S. Waldbusser, quot;Con- http://www.javvin.com/CyberGauge. formance Statements for SMIv2quot;, STD 58, RFC 2580, April 999. html Easy Network Service [RFC342] Case, J., Harrington, D., Presuhn, R. and B. Wijnen, quot;Message Processing and Dispatching for the Simple Network Management Protocol (SNMP)quot;, STD 62, RFC 342, December 2002. Monitor http://www.javvin.com/easy.html [RFC343] Levi, D., Meyer, P. and B. Stewart, quot;Simple Network Management Protocol (SNMP) Applica- Business Card Scanner tionsquot;, STD 62, RFC 343, December 2002. http://www.javvin.com/businesscard- [RFC344] Blumenthal, U. and B. Wijnen, quot;User-Based Security Model (USM) for Version 3 of the Simple scanner.html Network Management Protocol (SNMPv3)quot;, STD 62, RFC 344, December 2002. Color Cards and Picture Scanner [RFC345] Wijnen, B., Presuhn, R. and K. McCloghrie, quot;View-based Access Control Model (VACM) for http://www.javvin.com/colorcardscan- the Simple Network Management Protocol (SNMP)quot;, STD 62, RFC 345, December 2002. ner.html Portable Document Scan- [RFC346] Presuhn, R., Case, J., McCloghrie, K., Rose, M. and S. Waldbusser, quot;Protocol Operations for the Simple Network Management Protocol (SNMP)quot;, STD 62, RFC 346, December 2002. ner http://www.javvin.com/portablescan- [RFC347] Presuhn, R., Case, J., McCloghrie, K., Rose, M. and S. Waldbusser, quot;Transport Mappings for ner.html the Simple Network Management Protocol (SNMP)quot;, STD 62, RFC 347, December 2002. www.javvin.com [RFC348] Presuhn, R., Case, J., McCloghrie, K., Rose, M. and S. Waldbusser, quot;Management Informa- www.networkdictionary. tion Base (MIB) for the Simple Network Management Protocol (SNMP)quot;, STD 62, RFC 348, December 2002. com [ Page 36 ]
    • Architecture for SNMP Management Frameworks December 2002 Network Dictionary 10.2. Informative References http://www.javvin.com/networkdiction- ary.html [RFC1155] Rose, M. and K. McCloghrie, quot;Structure and Identification of Management Information for Network Protocols Map TCP/IP-based internetsquot;, STD 6, RFC 55, May 990. http://www.javvin.com/map.html [RFC57] Case, J., Fedor, M., Schoffstall, M. and J. Davin, quot;The Simple Network Management Protocolquot;, Network Security Map STD 5, RFC 57, May 990. http://www.javvin.com/securitymap. [RFC1212] Rose, M. and K. McCloghrie, quot;Concise MIB Definitionsquot;, STD 16, RFC 1212, March 1991. html Wireless Communications [RFC90] Case, J., McCloghrie, K., Rose, M. and S. Waldbusser, quot;Introduction to Community-based Technology Map SNMPv2quot;, RFC 90, January 996. http://www.javvin.com/wirelessmap. html [RFC909] McCloghrie, K., Editor, quot;An Administrative Infrastructure for SNMPv2quot;, RFC 909, February Network Protocols Hand- 996. book [RFC90] Waters, G., Editor, quot;User-based Security Model for SNMPv2quot;, RFC 90, February 996. http://www.javvin.com/model.html TCP/IP Quick Guide [RFC2028] Hovey, R. and S. Bradner, quot;The Organizations Involved in the IETF Standards Processquot;, BCP , RFC 2028, October 996. http://www.javvin.com/tcpipguide.html [RFC2576] Frye, R., Levi, D., Routhier, S. and B. Wijnen, quot;Coexistence between Version , Version 2, and Ethernet Quick Guide Version 3 of the Internet-Standard Network Management Frameworkquot;, RFC 2576, March 2000. http://www.javvin.com/ethernetguide. [RFC2863] McCloghrie, K. and F. Kastenholz, quot;The Interfaces Group MIBquot;, RFC 2863, June 2000. html Packet Analyzer [RFC340] Case, J., Mundy, R., Partain, D. and B. Stewart, quot;Introduction and Applicability Statements for Internet- Standard Management Frameworkquot;, RFC 340, December 2002. http://www.javvin.com/packet.html DiskShare Appendix A http://www.javvin.com/diskshare.html A. Guidelines for Model Designers DiskAccess http://www.javvin.com/diskaccess.html This appendix describes guidelines for designers of models which are expected to fit into the architecture defined in this document. LANsurveyor http://www.javvin.com/LANsurveyor. SNMPv and SNMPv2c are two SNMP frameworks which use communities to provide trivial authenti- html cation and access control. SNMPv and SNMPv2c Frameworks can coexist with Frameworks designed according to this architecture, and modified versions of SNMPv1 and SNMPv2c Frameworks could be CyberGauge designed to meet the requirements of this architecture, but this document does not provide guidelines for http://www.javvin.com/CyberGauge. that coexistence. html Within any subsystem model, there should be no reference to any specific model of another subsystem, or Easy Network Service to data defined by a specific model of another subsystem. Monitor http://www.javvin.com/easy.html Transfer of data between the subsystems is deliberately described as a fixed set of abstract data elements and primitive functions which can be overloaded to satisfy the needs of multiple model definitions. Business Card Scanner http://www.javvin.com/businesscard- Documents which define models to be used within this architecture SHOULD use the standard primi- scanner.html tives between subsystems, possibly defining specific mechanisms for converting the abstract data elements Color Cards and Picture into model-usable formats. This constraint exists to allow subsystem and model documents to be written Scanner recognizing common borders of the subsystem and model. Vendors are not constrained to recognize these borders in their implementations. http://www.javvin.com/colorcardscan- ner.html The architecture defines certain standard services to be provided between subsystems, and the architecture Portable Document Scan- defines abstract service interfaces to request these services. ner http://www.javvin.com/portablescan- Each model definition for a subsystem SHOULD support the standard service interfaces, but whether, or ner.html how, or how well, it performs the service is dependent on the model definition. www.javvin.com A.1. Security Model Design Requirements www.networkdictionary. com [ Page 37 ]
    • Architecture for SNMP Management Frameworks December 2002 A.1.1. Threats Network Dictionary http://www.javvin.com/networkdiction- ary.html A document describing a Security Model MUST describe how the model protects against the threats de- scribed under quot;Security Requirements of this Architecturequot;, section .4. Network Protocols Map http://www.javvin.com/map.html A.1.2. Security Processing Network Security Map Received messages MUST be validated by a Model of the Security Subsystem. Validation includes authen- http://www.javvin.com/securitymap. tication and privacy processing if needed, but it is explicitly allowed to send messages which do not require html authentication or privacy. Wireless Communications A received message contains a specified securityLevel to be used during processing. All messages requiring Technology Map privacy MUST also require authentication. http://www.javvin.com/wirelessmap. html A Security Model specifies rules by which authentication and privacy are to be done. A model may de- Network Protocols Hand- fine mechanisms to provide additional security features, but the model definition is constrained to using book (possibly a subset of) the abstract data elements defined in this document for transferring data between subsystems. http://www.javvin.com/model.html TCP/IP Quick Guide Each Security Model may allow multiple security protocols to be used concurrently within an implementa- http://www.javvin.com/tcpipguide.html tion of the model. Each Security Model defines how to determine which protocol to use, given the secu- rityLevel and the security parameters relevant to the message. Each Security Model, with its associated protocol(s) defines how the sending/receiving entities are identified, and how secrets are configured. Ethernet Quick Guide http://www.javvin.com/ethernetguide. Authentication and Privacy protocols supported by Security Models are uniquely identified using Object html Identifiers. IETF standard protocols for authentication or privacy should have an identifier defined within the snmpAuthProtocols or the snmpPrivProtocols subtrees. Enterprise specific protocol identifiers should Packet Analyzer be defined within the enterprise subtree. http://www.javvin.com/packet.html For privacy, the Security Model defines what portion of the message is encrypted. DiskShare The persistent data used for security should be SNMP-manageable, but the Security Model defines whether http://www.javvin.com/diskshare.html an instantiation of the MIB is a conformance requirement. DiskAccess Security Models are replaceable within the Security Subsystem. Multiple Security Model implementations http://www.javvin.com/diskaccess.html may exist concurrently within an SNMP engine. The number of Security Models defined by the SNMP community should remain small to promote interoperability. LANsurveyor http://www.javvin.com/LANsurveyor. A.1.3. Validate the security-stamp in a received message html CyberGauge A Message Processing Model requests that a Security Model: http://www.javvin.com/CyberGauge. - verifies that the message has not been altered, html Easy Network Service - authenticates the identification of the principal for whom the message was generated. Monitor - decrypts the message if it was encrypted. http://www.javvin.com/easy.html Business Card Scanner Additional requirements may be defined by the model, and additional services may be provided by the model, but the model is constrained to use the following primitives for transferring data between subsys- http://www.javvin.com/businesscard- tems. Implementations are not so constrained. scanner.html Color Cards and Picture A Message Processing Model uses the processIncomingMsg primitive as described in section 4.4.2. Scanner http://www.javvin.com/colorcardscan- A.1.4. Security MIBs ner.html Portable Document Scan- Each Security Model defines the MIB module(s) required for security processing, including any MIB ner module(s) required for the security protocol(s) supported. The MIB module(s) SHOULD be defined con- http://www.javvin.com/portablescan- currently with the procedures which use the MIB module(s). The MIB module(s) are subject to normal ner.html access control rules. www.javvin.com The mapping between the model-dependent security ID and the securityName MUST be able to be de- termined using SNMP, if the model- dependent MIB is instantiated and if access control policy allows www.networkdictionary. access. com [ Page 38 ]
    • Architecture for SNMP Management Frameworks December 2002 A.1.5. Cached Security Data Network Dictionary http://www.javvin.com/networkdiction- ary.html For each message received, the Security Model caches the state information such that a Response message can be generated using the same security information, even if the Local Configuration Datastore is altered Network Protocols Map between the time of the incoming request and the outgoing response. http://www.javvin.com/map.html A Message Processing Model has the responsibility for explicitly releasing the cached data if such data is Network Security Map no longer needed. To enable this, an abstract securityStateReference data element is passed from the Secu- rity Model to the Message Processing Model. http://www.javvin.com/securitymap. html The cached security data may be implicitly released via the generation of a response, or explicitly released Wireless Communications by using the stateRelease primitive, as described in section 4.5.. Technology Map http://www.javvin.com/wirelessmap. A.2. Message Processing Model Design Requirements html Network Protocols Hand- An SNMP engine contains a Message Processing Subsystem which may contain multiple Message Pro- book cessing Models. http://www.javvin.com/model.html The Message Processing Model MUST always (conceptually) pass the complete PDU, i.e., it never for- TCP/IP Quick Guide wards less than the complete list of varBinds. http://www.javvin.com/tcpipguide.html A.2.1. Receiving an SNMP Message from the Network Ethernet Quick Guide Upon receipt of a message from the network, the Dispatcher in the SNMP engine determines the version http://www.javvin.com/ethernetguide. of the SNMP message and interacts with the corresponding Message Processing Model to determine the html abstract data elements. Packet Analyzer A Message Processing Model specifies the SNMP Message format it supports and describes how to deter- http://www.javvin.com/packet.html mine the values of the abstract data elements (like msgID, msgMaxSize, msgFlags, msgSecurityParam- eters, securityModel, securityLevel etc). A Message Processing Model interacts with a Security Model DiskShare to provide security processing for the message using the processIncomingMsg primitive, as described in http://www.javvin.com/diskshare.html section 4.4.2. DiskAccess A.2.2. Sending an SNMP Message to the Network http://www.javvin.com/diskaccess.html The Dispatcher in the SNMP engine interacts with a Message Processing Model to prepare an outgoing LANsurveyor message. For that it uses the following primitives: http://www.javvin.com/LANsurveyor. html - for requests and notifications: prepareOutgoingMessage, as described in section 4.2.1. CyberGauge - for response messages: prepareResponseMessage, as described in section 4.2.2. http://www.javvin.com/CyberGauge. html A Message Processing Model, when preparing an Outgoing SNMP Message, interacts with a Security Model to secure the message. For that it uses the following primitives: Easy Network Service Monitor - for requests and notifications: generateRequestMsg, as described in section 4.4.1. http://www.javvin.com/easy.html - for response messages: generateResponseMsg as described in section 4.4.3. Business Card Scanner http://www.javvin.com/businesscard- Once the SNMP message is prepared by a Message Processing Model, the Dispatcher sends the message to scanner.html the desired address using the appropriate transport. Color Cards and Picture Scanner A.3. Application Design Requirements http://www.javvin.com/colorcardscan- ner.html Within an application, there may be an explicit binding to a specific SNMP message version, i.e., a specific Portable Document Scan- Message Processing Model, and to a specific Access Control Model, but there should be no reference to any data defined by a specific Message Processing Model or Access Control Model. ner http://www.javvin.com/portablescan- Within an application, there should be no reference to any specific Security Model, or any data defined by ner.html a specific Security Model. www.javvin.com An application determines whether explicit or implicit access control should be applied to the operation, www.networkdictionary. and, if access control is needed, which Access Control Model should be used. com [ Page 39 ]
    • Architecture for SNMP Management Frameworks December 2002 Network Dictionary An application has the responsibility to define any MIB module(s) used to provide application-specific services. http://www.javvin.com/networkdiction- ary.html Applications interact with the SNMP engine to initiate messages, receive responses, receive asynchronous Network Protocols Map messages, and send responses. http://www.javvin.com/map.html A.3.1. Applications that Initiate Messages Network Security Map Applications may request that the SNMP engine send messages containing SNMP commands or notifica- http://www.javvin.com/securitymap. tions using the sendPdu primitive as described in section 4... html Wireless Communications If it is desired that a message be sent to multiple targets, it is the responsibility of the application to provide Technology Map the iteration. http://www.javvin.com/wirelessmap. html The SNMP engine assumes necessary access control has been applied to the PDU, and provides no access Network Protocols Hand- control services. book The SNMP engine looks at the quot;expectResponsequot; parameter, and if a response is expected, then the ap- http://www.javvin.com/model.html propriate information is cached such that a later response can be associated to this message, and can then TCP/IP Quick Guide be returned to the application. A sendPduHandle is returned to the application so it can later correspond the response with this message as well. http://www.javvin.com/tcpipguide.html A.3.2. Applications that Receive Responses Ethernet Quick Guide http://www.javvin.com/ethernetguide. The SNMP engine matches the incoming response messages to outstanding messages sent by this SNMP html engine, and forwards the response to the associated application using the processResponsePdu primitive, as described in section 4..4. Packet Analyzer http://www.javvin.com/packet.html A.3.3. Applications that Receive Asynchronous Messages DiskShare When an SNMP engine receives a message that is not the response to a request from this SNMP engine, it http://www.javvin.com/diskshare.html must determine to which application the message should be given. DiskAccess An Application that wishes to receive asynchronous messages registers itself with the engine using the http://www.javvin.com/diskaccess.html primitive registerContextEngineID as described in section 4..5. LANsurveyor An Application that wishes to stop receiving asynchronous messages should unregister itself with the http://www.javvin.com/LANsurveyor. SNMP engine using the primitive unregisterContextEngineID as described in section 4..5. html Only one registration per combination of PDU type and contextEngineID is permitted at the same time. CyberGauge Duplicate registrations are ignored. An errorIndication will be returned to the application that attempts to http://www.javvin.com/CyberGauge. duplicate a registration. html All asynchronously received messages containing a registered combination of PDU type and contextEngi- Easy Network Service neID are sent to the application which registered to support that combination. Monitor The engine forwards the PDU to the registered application, using the processPdu primitive, as described http://www.javvin.com/easy.html in section 4..2. Business Card Scanner http://www.javvin.com/businesscard- A.3.4. Applications that Send Responses scanner.html Color Cards and Picture Request operations require responses. An application sends a response via the returnResponsePdu primi- Scanner tive, as described in section 4..3. http://www.javvin.com/colorcardscan- The contextEngineID, contextName, securityModel, securityName, securityLevel, and stateReference ner.html parameters are from the initial processPdu primitive. The PDU and statusInformation are the results of Portable Document Scan- processing. ner http://www.javvin.com/portablescan- A.4. Access Control Model Design Requirements ner.html www.javvin.com An Access Control Model determines whether the specified securityName is allowed to perform the re- quested operation on a specified managed object. The Access Control Model specifies the rules by which www.networkdictionary. access control is determined. com [ Page 40 ]
    • Architecture for SNMP Management Frameworks December 2002 Network Dictionary The persistent data used for access control should be manageable using SNMP, but the Access Control Model defines whether an instantiation of the MIB is a conformance requirement. http://www.javvin.com/networkdiction- ary.html The Access Control Model must provide the primitive isAccessAllowed. Network Protocols Map Editors' Addresses http://www.javvin.com/map.html Network Security Map Bert Wijnen http://www.javvin.com/securitymap. Lucent Technologies html Schagen 33 Wireless Communications 346 GL Linschoten Technology Map Netherlands http://www.javvin.com/wirelessmap. Phone: +3 348-680-485 html EMail: bwijnen@lucent.com Network Protocols Hand- book http://www.javvin.com/model.html David Harrington Enterasys Networks TCP/IP Quick Guide Post Office Box 5005 http://www.javvin.com/tcpipguide.html 35 Industrial Way Rochester, New Hampshire 03866-5005 USA Ethernet Quick Guide http://www.javvin.com/ethernetguide. Phone: + 603-337-264 html EMail: dbh@enterasys.com Packet Analyzer http://www.javvin.com/packet.html Randy Presuhn BMC Software, Inc. DiskShare 24 North First Street http://www.javvin.com/diskshare.html San Jose, California 953 USA DiskAccess Phone: + 408-546-006 http://www.javvin.com/diskaccess.html Fax: + 408-965-0359 EMail: randy_presuhn@bmc.com LANsurveyor http://www.javvin.com/LANsurveyor. Full Copyright Statement html CyberGauge Copyright (C) The Internet Society (2002). All Rights Reserved. http://www.javvin.com/CyberGauge. html 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 implementation may be prepared, copied, published and Easy Network Service distributed, in whole or in part, without restriction of any kind, provided that the above copyright notice Monitor and this paragraph are included on all such copies and derivative works. However, this document itself http://www.javvin.com/easy.html 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 Business Card Scanner in which case the procedures for copyrights defined in the Internet Standards process must be followed, or http://www.javvin.com/businesscard- as required to translate it into languages other than English. scanner.html Color Cards and Picture The limited permissions granted above are perpetual and will not be revoked by the Internet Society or its Scanner successors or assigns. http://www.javvin.com/colorcardscan- This document and the information contained herein is provided on an quot;AS ISquot; basis and THE INTERNET ner.html SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIMS ALL WARRANTIES, Portable Document Scan- EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE ner OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WAR- http://www.javvin.com/portablescan- RANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. ner.html www.javvin.com Acknowledgement www.networkdictionary. Funding for the RFC Editor function is currently provided by the Internet Society. com [ Page 4 ]