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Network Working Group                                            D. LeviRequest for Comments: 2573                           SNMP Research, Inc.Obsoletes:2273                                                 P. MeyerCategory: Standards Track                   Secure Computing Corporation                                                              B. Stewart                                                           Cisco Systems                                                              April 1999SNMP ApplicationsStatus of this Memo   This document specifies an Internet standards track protocol for the   Internet community, and requests discussion and suggestions for   improvements.  Please refer to the current edition of the "Internet   Official Protocol Standards" (STD 1) for the standardization state   and status of this protocol.  Distribution of this memo is unlimited.Copyright Notice   Copyright (C) The Internet Society (1999). All Rights Reserved.Abstract   This memo describes five types of SNMP applications which make use of   an SNMP engine as described in [RFC2571].  The types of application   described are Command Generators, Command Responders, Notification   Originators, Notification Receivers, and Proxy Forwarders.   This memo also defines MIB modules for specifying targets of   management operations, for notification filtering, and for proxy   forwarding.Table Of Contents1 Overview .....................................................21.1 Command Generator Applications .............................31.2 Command Responder Applications .............................31.3 Notification Originator Applications .......................31.4 Notification Receiver Applications .........................31.5 Proxy Forwarder Applications ...............................42 Management Targets ...........................................53 Elements Of Procedure ........................................63.1 Command Generator Applications .............................63.2 Command Responder Applications .............................93.3 Notification Originator Applications .......................143.4 Notification Receiver Applications .........................17Levi, et al.                Standards Track                     [Page 1]

RFC 2573                   SNMP Applications                  April 19993.5 Proxy Forwarder Applications ...............................193.5.1 Request Forwarding .......................................203.5.1.1 Processing an Incoming Request .........................203.5.1.2 Processing an Incoming Response ........................233.5.1.3 Processing an Incoming Internal-Class PDU ..............243.5.2 Notification Forwarding ..................................254 The Structure of the MIB Modules .............................284.1 The Management Target MIB Module ...........................284.1.1 Tag Lists ................................................294.1.2 Definitions ..............................................304.2 The Notification MIB Module ................................434.2.1 Definitions ..............................................434.3 The Proxy MIB Module .......................................554.3.1 Definitions ..............................................55   5 Identification of Management Targets in Notification        Originators ...............................................616 Notification Filtering .......................................62   7 Management Target Translation in Proxy  Forwarder  Applica-        tions .....................................................637.1 Management Target Translation for Request Forwarding .......637.2 Management Target Translation for Notification Forwarding        ...........................................................648 Intellectual Property ........................................659 Acknowledgments ..............................................6610 Security Considerations .....................................6711 References ..................................................6712 Editors' Addresses...........................................69A. Trap Configuration Example ..................................70B. Full Copyright Statement ....................................721.  Overview   This document describes five types of SNMP applications:     - Applications which initiate SNMP Read-Class, and/or Write-Class       requests, called 'command generators.'     - Applications which respond to SNMP Read-Class, and/or Write-Class       requests, called 'command responders.'     - Applications which generate SNMP Notification-Class PDUs, called       'notification originators.'     - Applications which receive SNMP Notification-Class PDUs, called       'notification receivers.'     - Applications which forward SNMP messages, called 'proxy       forwarders.'Levi, et al.                Standards Track                     [Page 2]

RFC 2573                   SNMP Applications                  April 1999   Note that there are no restrictions on which types of applications   may be associated with a particular SNMP engine.  For example, a   single SNMP engine may, in fact, be associated with both command   generator and command responder applications.   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",   "SHOULD", "SHOULD NOT", "RECOMMENDED",  "MAY", and "OPTIONAL" in this   document are to be interpreted as described in [RFC2119].1.1.  Command Generator Applications   A command generator application initiates SNMP Read-Class and/or   Write-Class requests, as well as processing the response to a request   which it generated.1.2.  Command Responder Applications   A command responder application receives SNMP Read-Class and/or   Write-Class requests destined for the local system as indicated by   the fact that the contextEngineID in the received request is equal to   that of the local engine through which the request was received.  The   command responder application will perform the appropriate protocol   operation, using access control, and will generate a response message   to be sent to the request's originator.1.3.  Notification Originator Applications   A notification originator application conceptually monitors a system   for particular events or conditions, and generates Notification-Class   messages based on these events or conditions.  A notification   originator must have a mechanism for determining where to send   messages, and what SNMP version and security parameters to use when   sending messages.  A mechanism and MIB module for this purpose is   provided in this document.  Note that Notification-Class PDUs   generated by a notification originator may be either Confirmed-Class   or Unconfirmed-Class PDU types.1.4.  Notification Receiver Applications   A notification receiver application listens for notification   messages, and generates response messages when a message containing a   Confirmed-Class PDU is received.Levi, et al.                Standards Track                     [Page 3]

RFC 2573                   SNMP Applications                  April 19991.5.  Proxy Forwarder Applications   A proxy forwarder application forwards SNMP messages.  Note that   implementation of a proxy forwarder application is optional.  The   sections describing proxy (4.5, 5.3, and 8) may be skipped for   implementations that do not include a proxy forwarder application.   The term "proxy" has historically been used very loosely, with   multiple different meanings.  These different meanings include (among   others):   (1)  the forwarding of SNMP requests to other SNMP entities without        regard for what managed object types are being accessed; for        example, in order to forward an SNMP request from one transport        domain to another, or to translate SNMP requests of one version        into SNMP requests of another version;   (2)  the translation of SNMP requests into operations of some non-        SNMP management protocol; and   (3)  support for aggregated managed objects where the value of one        managed object instance depends upon the values of multiple        other (remote) items of management information.   Each of these scenarios can be advantageous; for example, support for   aggregation of management information can significantly reduce the   bandwidth requirements of large-scale management activities.   However, using a single term to cover multiple different scenarios   causes confusion.   To avoid such confusion, this document uses the term "proxy" with a   much more tightly defined meaning.  The term "proxy" is used in this   document to refer to a proxy forwarder application which forwards   either SNMP messages without regard for what managed objects are   contained within those messages.  This definition is most closely   related to the first definition above.  Note, however, that in the   SNMP architecture [RFC2571], a proxy forwarder is actually an   application, and need not be associated with what is traditionally   thought of as an SNMP agent.   Specifically, the distinction between a traditional SNMP agent and a   proxy forwarder application is simple:Levi, et al.                Standards Track                     [Page 4]

RFC 2573                   SNMP Applications                  April 1999     -  a proxy forwarder application forwards SNMP messages to other        SNMP engines according to the context, and irrespective of the        specific managed object types being accessed, and forwards the        response to such previously forwarded messages back to the SNMP        engine from which the original message was received;     -  in contrast, the command responder application that is part of        what is traditionally thought of as an SNMP agent, and which        processes SNMP requests according to the (names of the)        individual managed object types and instances being accessed, is        NOT a proxy forwarder application from the perspective of this        document.   Thus, when a proxy forwarder application forwards a request or   notification for a particular contextEngineID / contextName pair, not   only is the information on how to forward the request specifically   associated with that context, but the proxy forwarder application has   no need of a detailed definition of a MIB view (since the proxy   forwarder application forwards the request irrespective of the   managed object types).   In contrast, a command responder application must have the detailed   definition of the MIB view, and even if it needs to issue requests to   other entities, via SNMP or otherwise, that need is dependent on the   individual managed object instances being accessed (i.e., not only on   the context).   Note that it is a design goal of a proxy forwarder application to act   as an intermediary between the endpoints of a transaction.  In   particular, when forwarding Confirmed Notification-Class messages,   the associated response is forwarded when it is received from the   target to which the Notification-Class message was forwarded, rather   than generating a response immediately when the Notification-Class   message is received.2.  Management Targets   Some types of applications (notification generators and proxy   forwarders in particular) require a mechanism for determining where   and how to send generated messages.  This document provides a   mechanism and MIB module for this purpose.  The set of information   that describes where and how to send a message is called a '   Management Target', and consists of two kinds of information:     -  Destination information, consisting of a transport domain and a        transport address.  This is also termed a transport endpoint.Levi, et al.                Standards Track                     [Page 5]

RFC 2573                   SNMP Applications                  April 1999     -  SNMP parameters, consisting of message processing model,        security model, security level, and security name information.   The SNMP-TARGET-MIB module described later in this document contains   one table for each of these types of information.  There can be a   many-to-many relationship in the MIB between these two types of   information.  That is, there may be multiple transport endpoints   associated with a particular set of SNMP parameters, or a particular   transport endpoint may be associated with several sets of SNMP   parameters.3.  Elements Of Procedure   The following sections describe the procedures followed by each type   of application when generating messages for transmission or when   processing received messages.  Applications communicate with the   Dispatcher using the abstract service interfaces defined in   [RFC2571].3.1.  Command Generator Applications   A command generator initiates an SNMP request by calling the   Dispatcher using the following abstract service interface:       statusInformation =              -- sendPduHandle if success                                        -- errorIndication if failure         sendPdu(         IN   transportDomain           -- transport domain to be used         IN   transportAddress          -- destination network address         IN   messageProcessingModel    -- typically, SNMP version         IN   securityModel             -- Security Model to use         IN   securityName              -- on behalf of this principal         IN   securityLevel             -- Level of Security requested         IN   contextEngineID           -- data from/at this entity         IN   contextName               -- data from/in this context         IN   pduVersion                -- the version of the PDU         IN   PDU                       -- SNMP Protocol Data Unit         IN   expectResponse            -- TRUE or FALSE              )   Where:     -  The transportDomain is that of the destination of the message.     -  The transportAddress is that of the destination of the message.Levi, et al.                Standards Track                     [Page 6]

RFC 2573                   SNMP Applications                  April 1999     -  The messageProcessingModel indicates which Message Processing        Model the application wishes to use.     -  The securityModel is the security model that the application        wishes to use.     -  The securityName is the security model independent name for the        principal on whose behalf the application wishes the message is        to be generated.     -  The securityLevel is the security level that the application        wishes to use.     -  The contextEngineID is provided by the command generator if it        wishes to explicitly specify the location of the management        information it is requesting.     -  The contextName is provided by the command generator if it        wishes to explicitly specify the local context name for the        management information it is requesting.     -  The pduVersion indicates the version of the PDU to be sent.     -  The PDU is a value constructed by the command generator        containing the management operation that the command generator        wishes to perform.     -  The expectResponse argument indicates that a response is        expected.   The result of the sendPdu interface indicates whether the PDU was   successfully sent.  If it was successfully sent, the returned value   will be a sendPduHandle.  The command generator should store the   sendPduHandle so that it can correlate a response to the original   request.   The Dispatcher is responsible for delivering the response to a   particular request to the correct command generator application.  The   abstract service interface used is:       processResponsePdu(              -- process Response PDU         IN   messageProcessingModel    -- typically, SNMP version         IN   securityModel             -- Security Model in use         IN   securityName              -- on behalf of this principal         IN   securityLevel             -- Level of Security         IN   contextEngineID           -- data from/at this SNMP entity         IN   contextName               -- data from/in this context         IN   pduVersion                -- the version of the PDULevi, et al.                Standards Track                     [Page 7]

RFC 2573                   SNMP Applications                  April 1999         IN   PDU                       -- SNMP Protocol Data Unit         IN   statusInformation         -- success or errorIndication         IN   sendPduHandle             -- handle from sendPdu              )   Where:     -  The messageProcessingModel is the value from the received        response.     -  The securityModel is the value from the received response.     -  The securityName is the value from the received response.     -  The securityLevel is the value from the received response.     -  The contextEngineID is the value from the received response.     -  The contextName is the value from the received response.     -  The pduVersion indicates the version of the PDU in the received        response.     -  The PDU is the value from the received response.     -  The statusInformation indicates success or failure in receiving        the response.     -  The sendPduHandle is the value returned by the sendPdu call        which generated the original request to which this is a        response.   The procedure when a command generator receives a message is as   follows:   (1)  If the received values of messageProcessingModel, securityModel,        securityName, contextEngineID, contextName, and pduVersion are        not all equal to the values used in the original request, the        response is discarded.   (2)  The operation type, request-id, error-status, error-index, and        variable-bindings are extracted from the PDU and saved.  If the        request-id is not equal to the value used in the original        request, the response is discarded.   (3)  At this point, it is up to the application to take an        appropriate action.  The specific action is implementation        dependent.  If the statusInformation indicates that the requestLevi, et al.                Standards Track                     [Page 8]

RFC 2573                   SNMP Applications                  April 1999        failed, an appropriate action might be to attempt to transmit        the request again, or to notify the person operating the        application that a failure occurred.3.2.  Command Responder Applications   Before a command responder application can process messages, it must   first associate itself with an SNMP engine.  The abstract service   interface used for this purpose is:       statusInformation =        -- success or errorIndication         registerContextEngineID(         IN   contextEngineID     -- take responsibility for this one         IN   pduType             -- the pduType(s) to be registered              )   Where:     -  The statusInformation indicates success or failure of the        registration attempt.     -  The contextEngineID is equal to the snmpEngineID of the SNMP        engine with which the command responder is registering.     -  The pduType indicates a Read-Class and/or Write-Class PDU.   Note that if another command responder application is already   registered with an SNMP engine, any further attempts to register with   the same contextEngineID and pduType will be denied.  This implies   that separate command responder applications could register   separately for the various pdu types.  However, in practice this is   undesirable, and only a single command responder application should   be registered with an SNMP engine at any given time.   A command responder application can disassociate with an SNMP engine   using the following abstract service interface:       unregisterContextEngineID(         IN   contextEngineID     -- give up responsibility for this one         IN   pduType             -- the pduType(s) to be unregistered              )   Where:     -  The contextEngineID is equal to the snmpEngineID of the SNMP        engine with which the command responder is cancelling the        registration.Levi, et al.                Standards Track                     [Page 9]

RFC 2573                   SNMP Applications                  April 1999     -  The pduType indicates a Read-Class and/or Write-Class PDU.   Once the command responder has registered with the SNMP engine, it   waits to receive SNMP messages.  The abstract service interface used   for receiving messages is:   processPdu(                     -- process Request/Notification PDU     IN   messageProcessingModel   -- typically, SNMP version     IN   securityModel            -- Security Model in use     IN   securityName             -- on behalf of this principal     IN   securityLevel            -- Level of Security     IN   contextEngineID          -- data from/at this SNMP entity     IN   contextName              -- data from/in this context     IN   pduVersion               -- the version of the PDU     IN   PDU                      -- SNMP Protocol Data Unit     IN   maxSizeResponseScopedPDU -- maximum size of the Response PDU     IN   stateReference           -- reference to state information          )                        -- needed when sending a response   Where:     -  The messageProcessingModel indicates which Message Processing        Model received and processed the message.     -  The securityModel is the value from the received message.     -  The securityName is the value from the received message.     -  The securityLevel is the value from the received message.     -  The contextEngineID is the value from the received message.     -  The contextName is the value from the received message.     -  The pduVersion indicates the version of the PDU in the received        message.     -  The PDU is the value from the received message.     -  The maxSizeResponseScopedPDU is the maximum allowable size of a        ScopedPDU containing a Response PDU (based on the maximum        message size that the originator of the message can accept).     -  The stateReference is a value which references cached        information about each received request message.  This value        must be returned to the Dispatcher in order to generate a        response.Levi, et al.                Standards Track                    [Page 10]

RFC 2573                   SNMP Applications                  April 1999   The procedure when a message is received is as follows.   (1)  The operation type is determined from the ASN.1 tag value        associated with the PDU parameter.  The operation type should        always be one of the types previously registered by the        application.   (2)  The request-id is extracted from the PDU and saved.   (3)  Any PDU type specific parameters are extracted from the PDU and        saved (for example, if the PDU type is an SNMPv2 GetBulk PDU,        the non-repeaters and max-repetitions values are extracted).   (4)  The variable-bindings are extracted from the PDU and saved.   (5)  The management operation represented by the PDU type is        performed with respect to the relevant MIB view within the        context named by the contextName (for an SNMPv2 PDU type, the        operation is performed according to the procedures set forth in        [RFC1905]).  The relevant MIB view is determined by the        securityLevel, securityModel, contextName, securityName, and the        class of the PDU type.  To determine whether a particular object        instance is within the relevant MIB view, the following abstract        service interface is called:       statusInformation =      -- success or errorIndication         isAccessAllowed(         IN   securityModel     -- Security Model in use         IN   securityName      -- principal who wants to access         IN   securityLevel     -- Level of Security         IN   viewType          -- read, write, or notify view         IN   contextName       -- context containing variableName         IN   variableName      -- OID for the managed object              )   Where:     -  The securityModel is the value from the received message.     -  The securityName is the value from the received message.     -  The securityLevel is the value from the received message.     -  The viewType indicates whether the PDU type is a Read-Class or        Write-Class operation.     -  The contextName is the value from the received message.Levi, et al.                Standards Track                    [Page 11]

RFC 2573                   SNMP Applications                  April 1999     -  The variableName is the object instance of the variable for        which access rights are to be checked.   Normally, the result of the management operation will be a new PDU   value, and processing will continue in step (6) below.  However, at   any time during the processing of the management operation:     -  If the isAccessAllowed ASI returns a noSuchView, noAccessEntry,        or noGroupName error, processing of the management operation is        halted, a PDU value is constructed using the values from the        originally received PDU, but replacing the error_status with an        authorizationError code, and error_index value of 0, and control        is passed to step (6) below.     -  If the isAccessAllowed ASI returns an otherError, processing of        the management operation is halted, a different PDU value is        constructed using the values from the originally received PDU,        but replacing the error_status with a genError code, and control        is passed to step (6) below.     -  If the isAccessAllowed ASI returns a noSuchContext error,        processing of the management operation is halted, no result PDU        is generated, the snmpUnknownContexts counter is incremented,        and control is passed to step (6) below.     -  If the context named by the contextName parameter is        unavailable, processing of the management operation is halted,        no result PDU is generated, the snmpUnavailableContexts counter        is incremented, and control is passed to step (6) below.   (6)  The Dispatcher is called to generate a response or report        message.  The abstract service interface is:   returnResponsePdu(     IN   messageProcessingModel   -- typically, SNMP version     IN   securityModel            -- Security Model in use     IN   securityName             -- on behalf of this principal     IN   securityLevel            -- same as on incoming request     IN   contextEngineID          -- data from/at this SNMP entity     IN   contextName              -- data from/in this context     IN   pduVersion               -- the version of the PDU     IN   PDU                      -- SNMP Protocol Data Unit     IN   maxSizeResponseScopedPDU -- maximum size of the Response PDU     IN   stateReference           -- reference to state information                                   -- as presented with the request     IN   statusInformation        -- success or errorIndication          )                        -- error counter OID/value if errorLevi, et al.                Standards Track                    [Page 12]

RFC 2573                   SNMP Applications                  April 1999   Where:     -  The messageProcessingModel is the value from the processPdu        call.     -  The securityModel is the value from the processPdu call.     -  The securityName is the value from the processPdu call.     -  The securityLevel is the value from the processPdu call.     -  The contextEngineID is the value from the processPdu call.     -  The contextName is the value from the processPdu call.     -  The pduVersion indicates the version of the PDU to be returned.        If no result PDU was generated, the pduVersion is an undefined        value.     -  The PDU is the result generated in step (5) above.  If no result        PDU was generated, the PDU is an undefined value.     -  The maxSizeResponseScopedPDU is a local value indicating the        maximum size of a ScopedPDU that the application can accept.     -  The stateReference is the value from the processPdu call.     -  The statusInformation either contains an indication that no        error occurred and that a response should be generated, or        contains an indication that an error occurred along with the OID        and counter value of the appropriate error counter object.   Note that a command responder application should always call the   returnResponsePdu abstract service interface, even in the event of an   error such as a resource allocation error.  In the event of such an   error, the PDU value passed to returnResponsePdu should contain   appropriate values for errorStatus and errorIndex.   Note that the text above describes situations where the   snmpUnknownContexts counter is incremented, and where the   snmpUnavailableContexts counter is incremented.  The difference   between these is that the snmpUnknownContexts counter is incremented   when a request is received for a context which unknown to the SNMP   entity.  The snmpUnavailableContexts counter is incremented when a   request is received for a context which is known to the SNMP entity,   but is currently unavailable.  Determining when a context isLevi, et al.                Standards Track                    [Page 13]

RFC 2573                   SNMP Applications                  April 1999   unavailable is implementation specific, and some implementations may   never encounter this situation, and so may never increment the   snmpUnavailableContexts counter.3.3.  Notification Originator Applications   A notification originator application generates SNMP messages   containing Notification-Class PDUs (for example, SNMPv2-Trap PDUs or   Inform PDUs).  There is no requirement as to what specific types of   Notification-Class PDUs a particular implementation must be capable   of generating.   Notification originator applications require a mechanism for   identifying the management targets to which notifications should be   sent.  The particular mechanism used is implementation dependent.   However, if an implementation makes the configuration of management   targets SNMP manageable, it MUST use the SNMP-TARGET-MIB module   described in this document.   When a notification originator wishes to generate a notification, it   must first determine in which context the information to be conveyed   in the notification exists, i.e., it must determine the   contextEngineID and contextName.  It must then determine the set of   management targets to which the notification should be sent.  The   application must also determine, for each management target, what   specific PDU type the notification message should contain, and if it   is to contain a Confirmed-Class PDU, the number of retries and   retransmission algorithm.   The mechanism by which a notification originator determines this   information is implementation dependent.  Once the application has   determined this information, the following procedure is performed for   each management target:   (1)  Any appropriate filtering mechanisms are applied to determine        whether the notification should be sent to the management        target.  If such filtering mechanisms determine that the        notification should not be sent, processing continues with the        next management target.  Otherwise,   (2)  The appropriate set of variable-bindings is retrieved from local        MIB instrumentation within the relevant MIB view.  The relevant        MIB view is determined by the securityLevel, securityModel,        contextName, and securityName of the management target.  To        determine whether a particular object instance is within the        relevant MIB view, the isAccessAllowed abstract service        interface is used, in the same manner as described in theLevi, et al.                Standards Track                    [Page 14]

RFC 2573                   SNMP Applications                  April 1999        preceding section.  If the statusInformation returned by        isAccessAllowed does not indicate accessAllowed, the        notification is not sent to the management target.   (3)  The NOTIFICATION-TYPE OBJECT IDENTIFIER of the notification        (this is the value of the element of the variable bindings whose        name is snmpTrapOID.0, i.e., the second variable binding) is        checked using the isAccessAllowed abstract service interface,        using the same parameters used in the preceding step.  If the        statusInformation returned by isAccessAllowed does not indicate        accessAllowed, the notification is not sent to the management        target.   (4)  A PDU is constructed using a locally unique request-id value, a        PDU type as determined by the implementation, an error-status        and error-index value of 0, and the variable-bindings supplied        previously in step (2).   (5)  If the notification contains an Unconfirmed-Class PDU, the        Dispatcher is called using the following abstract service        interface:       statusInformation =              -- sendPduHandle if success                                        -- errorIndication if failure         sendPdu(         IN   transportDomain           -- transport domain to be used         IN   transportAddress          -- destination network address         IN   messageProcessingModel    -- typically, SNMP version         IN   securityModel             -- Security Model to use         IN   securityName              -- on behalf of this principal         IN   securityLevel             -- Level of Security requested         IN   contextEngineID           -- data from/at this entity         IN   contextName               -- data from/in this context         IN   pduVersion                -- the version of the PDU         IN   PDU                       -- SNMP Protocol Data Unit         IN   expectResponse            -- TRUE or FALSE              )   Where:     -  The transportDomain is that of the management target.     -  The transportAddress is that of the management target.     -  The messageProcessingModel is that of the management target.     -  The securityModel is that of the management target.Levi, et al.                Standards Track                    [Page 15]

RFC 2573                   SNMP Applications                  April 1999     -  The securityName is that of the management target.     -  The securityLevel is that of the management target.     -  The contextEngineID is the value originally determined for the        notification.     -  The contextName is the value originally determined for the        notification.     -  The pduVersion is the version of the PDU to be sent.     -  The PDU is the value constructed in step (3) above.     -  The expectResponse argument indicates that no response is        expected.   Otherwise,   (6)  If the notification contains a Confirmed-Class PDU, then:        a)  The Dispatcher is called using the sendPdu abstract service            interface as described in step (4) above, except that the            expectResponse argument indicates that a response is            expected.        b)  The application caches information about the management            target.        c)  If a response is received within an appropriate time            interval from the transport endpoint of the management            target, the notification is considered acknowledged and the            cached information is deleted.  Otherwise,        d)  If a response is not received within an appropriate time            period, or if a report indication is received, information            about the management target is retrieved from the cache, and            steps a) through d) are repeated.  The number of times these            steps are repeated is equal to the previously determined            retry count.  If this retry count is exceeded, the            acknowledgement of the notification is considered to have            failed, and processing of the notification for this            management target is halted.  Note that some report            indications might be considered a failure.  Such report            indications should be interpreted to mean that the            acknowledgement of the notification has failed.Levi, et al.                Standards Track                    [Page 16]

RFC 2573                   SNMP Applications                  April 1999   Responses to Confirmed-Class PDU notifications will be received via   the processResponsePdu abstract service interface.   To summarize, the steps that a notification originator follows when   determining where to send a notification are:     -  Determine the targets to which the notification should be sent.     -  Apply any required filtering to the list of targets.     -  Determine which targets are authorized to receive the        notification.3.4.  Notification Receiver Applications   Notification receiver applications receive SNMP Notification messages   from the Dispatcher.  Before any messages can be received, the   notification receiver must register with the Dispatcher using the   registerContextEngineID abstract service interface.  The parameters   used are:     -  The contextEngineID is an undefined 'wildcard' value.        Notifications are delivered to a registered notification        receiver regardless of the contextEngineID contained in the        notification message.     -  The pduType indicates the type of notifications that the        application wishes to receive (for example, SNMPv2-Trap PDUs or        Inform PDUs).   Once the notification receiver has registered with the Dispatcher,   messages are received using the processPdu abstract service   interface.  Parameters are:     -  The messageProcessingModel indicates which Message Processing        Model received and processed the message.     -  The securityModel is the value from the received message.     -  The securityName is the value from the received message.     -  The securityLevel is the value from the received message.     -  The contextEngineID is the value from the received message.     -  The contextName is the value from the received message.Levi, et al.                Standards Track                    [Page 17]

RFC 2573                   SNMP Applications                  April 1999     -  The pduVersion indicates the version of the PDU in the received        message.     -  The PDU is the value from the received message.     -  The maxSizeResponseScopedPDU is the maximum allowable size of a        ScopedPDU containing a Response PDU (based on the maximum        message size that the originator of the message can accept).     -  If the message contains an Unconfirmed-Class PDU, the        stateReference is undefined and unused.  Otherwise, the        stateReference is a value which references cached information        about the notification.  This value must be returned to the        Dispatcher in order to generate a response.   When an Unconfirmed-Class PDU is delivered to a notification receiver   application, it first extracts the SNMP operation type, request-id,   error-status, error-index, and variable-bindings from the PDU.  After   this, processing depends on the particular implementation.   When a Confirmed-Class PDU is received, the notification receiver   application follows the following procedure:   (1)  The PDU type, request-id, error-status, error-index, and        variable-bindings are extracted from the PDU.   (2)  A Response-Class PDU is constructed using the extracted        request-id and variable-bindings, and with error-status and        error-index both set to 0.   (3)  The Dispatcher is called to generate a response message using        the returnResponsePdu abstract service interface.  Parameters        are:     -  The messageProcessingModel is the value from the processPdu        call.     -  The securityModel is the value from the processPdu call.     -  The securityName is the value from the processPdu call.     -  The securityLevel is the value from the processPdu call.     -  The contextEngineID is the value from the processPdu call.     -  The contextName is the value from the processPdu call.     -  The pduVersion indicates the version of the PDU to be returned.Levi, et al.                Standards Track                    [Page 18]

RFC 2573                   SNMP Applications                  April 1999     -  The PDU is the result generated in step (2) above.     -  The maxSizeResponseScopedPDU is a local value indicating the        maximum size of a ScopedPDU that the application can accept.     -  The stateReference is the value from the processPdu call.     -  The statusInformation indicates that no error occurred and that        a response should be generated.3.5.  Proxy Forwarder Applications   A proxy forwarder application deals with forwarding SNMP messages.   There are four basic types of messages which a proxy forwarder   application may need to forward.  These are grouped according to the   class of PDU type contained in a message.  The four basic types of   messages are:     -  Those containing Read-Class or Write-Class PDU types (for        example, Get, GetNext, GetBulk, and Set PDU types).  These deal        with requesting or modifying information located within a        particular context.     -  Those containing Notification-Class PDU types (for example,        SNMPv2-Trap and Inform PDU types).  These deal with        notifications concerning information located within a particular        context.     -  Those containing a Response-Class PDU type.  Forwarding of        Response PDUs always occurs as a result of receiving a response        to a previously forwarded message.     -  Those containing Internal-Class PDU types (for example, a Report        PDU).  Forwarding of Internal-Class PDU types always occurs as a        result of receiving an Internal-Class PDU in response to a        previously forwarded message.   For the first type, the proxy forwarder's role is to deliver a   request for management information to an SNMP engine which is   "closer" or "downstream in the path" to the SNMP engine which has   access to that information, and to deliver the response containing   the information back to the SNMP engine from which the request was   received.  The context information in a request is used to determine   which SNMP engine has access to the requested information, and this   is used to determine where and how to forward the request.Levi, et al.                Standards Track                    [Page 19]

RFC 2573                   SNMP Applications                  April 1999   For the second type, the proxy forwarder's role is to determine which   SNMP engines should receive notifications about management   information from a particular location.  The context information in a   notification message determines the location to which the information   contained in the notification applies.  This is used to determine   which SNMP engines should receive notification about this   information.   For the third type, the proxy forwarder's role is to determine which   previously forwarded request or notification (if any) the response   matches, and to forward the response back to the initiator of the   request or notification.   For the fourth type, the proxy forwarder's role is to determine which   previously forwarded request or notification (if any) the Internal-   Class PDU matches, and to forward the Internal-Class PDU back to the   initiator of the request or notification.   When forwarding messages, a proxy forwarder application must perform   a translation of incoming management target information into outgoing   management target information.  How this translation is performed is   implementation specific.  In many cases, this will be driven by a   preconfigured translation table.  If a proxy forwarder application   makes the contents of this table SNMP manageable, it MUST use the   SNMP-PROXY-MIB module defined in this document.3.5.1.  Request Forwarding   There are two phases for request forwarding.  First, the incoming   request needs to be passed through the proxy application.  Then, the   resulting response needs to be passed back.  These phases are   described in the following two sections.3.5.1.1.  Processing an Incoming Request   A proxy forwarder application that wishes to forward request messages   must first register with the Dispatcher using the   registerContextEngineID abstract service interface.  The proxy   forwarder must register each contextEngineID for which it wishes to   forward messages, as well as for each pduType.  Note that as the   configuration of a proxy forwarder is changed, the particular   contextEngineID values for which it is forwarding may change.  The   proxy forwarder should call the registerContextEngineID and   unregisterContextEngineID abstract service interfaces as needed to   reflect its current configuration.Levi, et al.                Standards Track                    [Page 20]

RFC 2573                   SNMP Applications                  April 1999   A proxy forwarder application should never attempt to register a   value of contextEngineID which is equal to the snmpEngineID of the   SNMP engine to which the proxy forwarder is associated.   Once the proxy forwarder has registered for the appropriate   contextEngineID values, it can start processing messages.  The   following procedure is used:   (1)  A message is received using the processPdu abstract service        interface.  The incoming management target information received        from the processPdu interface is translated into outgoing        management target information.  Note that this translation may        vary for different values of contextEngineID and/or contextName.        The translation should result in a single management target.   (2)  If appropriate outgoing management target information cannot be        found, the proxy forwarder increments the snmpProxyDrops counter        [RFC1907], and then calls the Dispatcher using the        returnResponsePdu abstract service interface.  Parameters are:     -  The messageProcessingModel is the value from the processPdu        call.     -  The securityModel is the value from the processPdu call.     -  The securityName is the value from the processPdu call.     -  The securityLevel is the value from the processPdu call.     -  The contextEngineID is the value from the processPdu call.     -  The contextName is the value from the processPdu call.     -  The pduVersion is the value from the processPdu call.     -  The PDU is an undefined value.     -  The maxSizeResponseScopedPDU is a local value indicating the        maximum size of a ScopedPDU that the application can accept.     -  The stateReference is the value from the processPdu call.     -  The statusInformation indicates that an error occurred and        includes the OID and value of the snmpProxyDrops object.        Processing of the message stops at this point.  Otherwise,Levi, et al.                Standards Track                    [Page 21]

RFC 2573                   SNMP Applications                  April 1999   (3)  A new PDU is constructed.  A unique value of request-id should        be used in the new PDU (this value will enable a subsequent        response message to be correlated with this request).  The        remainder of the new PDU is identical to the received PDU,        unless the incoming SNMP version and the outgoing SNMP version        support different PDU versions, in which case the proxy        forwarder may need to perform a translation on the PDU (A method        for performing such a translation is described in [COEX].)   (4)  The proxy forwarder calls the Dispatcher to generate the        forwarded message, using the sendPdu abstract service interface.        The parameters are:     -  The transportDomain is that of the outgoing management target.     -  The transportAddress is that of the outgoing management target.     -  The messageProcessingModel is that of the outgoing management        target.     -  The securityModel is that of the outgoing management target.     -  The securityName is that of the outgoing management target.     -  The securityLevel is that of the outgoing management target.     -  The contextEngineID is the value originally received.     -  The contextName is the value originally received.     -  The pduVersion is the version of the PDU to be sent.     -  The PDU is the value constructed in step (3) above.     -  The expectResponse argument indicates that a response is        expected.  If the sendPdu call is unsuccessful, the proxy        forwarder performs the steps described in (2) above.  Otherwise:   (5)  The proxy forwarder caches the following information in order to        match an incoming response to the forwarded request:     -  The sendPduHandle returned from the call to sendPdu,     -  The request-id from the received PDU.     -  the contextEngineID,     -  the contextName,Levi, et al.                Standards Track                    [Page 22]

RFC 2573                   SNMP Applications                  April 1999     -  the stateReference,     -  the incoming management target information,     -  the outgoing management information,     -  any other information needed to match an incoming response to        the forwarded request.        If this information cannot be cached (possibly due to a lack of        resources), the proxy forwarder performs the steps described in        (2) above.  Otherwise:   (6)  Processing of the request stops until a response to the        forwarded request is received, or until an appropriate time        interval has expired.  If this time interval expires before a        response has been received, the cached information about this        request is removed.3.5.1.2.  Processing an Incoming Response   A proxy forwarder follows the following procedure when an incoming   response is received:   (1)  The incoming response is received using the processResponsePdu        interface.  The proxy forwarder uses the received parameters to        locate an entry in its cache of pending forwarded requests.        This is done by matching the received parameters with the cached        values of sendPduHandle, contextEngineID, contextName, outgoing        management target information, and the request-id contained in        the received PDU (the proxy forwarder must extract the request-        id for this purpose).  If an appropriate cache entry cannot be        found, processing of the response is halted.  Otherwise:   (2)  The cache information is extracted, and removed from the cache.   (3)  A new Response-Class PDU is constructed, using the request-id        value from the original forwarded request (as extracted from the        cache).  All other values are identical to those in the received        Response-Class PDU, unless the incoming SNMP version and the        outgoing SNMP version support different PDU versions, in which        case the proxy forwarder may need to perform a translation on        the PDU.  (A method for performing such a translation is        described in [COEX].)   (4)  The proxy forwarder calls the Dispatcher using the        returnResponsePdu abstract service interface.  Parameters are:Levi, et al.                Standards Track                    [Page 23]

RFC 2573                   SNMP Applications                  April 1999     -  The messageProcessingModel indicates the Message Processing        Model by which the original incoming message was processed.     -  The securityModel is that of the original incoming management        target extracted from the cache.     -  The securityName is that of the original incoming management        target extracted from the cache.     -  The securityLevel is that of the original incoming management        target extracted from the cache.     -  The contextEngineID is the value extracted from the cache.     -  The contextName is the value extracted from the cache.     -  The pduVersion indicates the version of the PDU to be returned.     -  The PDU is the (possibly translated) Response PDU.     -  The maxSizeResponseScopedPDU is a local value indicating the        maximum size of a ScopedPDU that the application can accept.     -  The stateReference is the value extracted from the cache.     -  The statusInformation indicates that no error occurred and that        a Response PDU message should be generated.3.5.1.3.  Processing an Incoming Internal-Class PDU   A proxy forwarder follows the following procedure when an incoming   Internal-Class PDU is received:   (1)  The incoming Internal-Class PDU is received using the        processResponsePdu interface.  The proxy forwarder uses the        received parameters to locate an entry in its cache of pending        forwarded requests.  This is done by matching the received        parameters with the cached values of sendPduHandle.  If an        appropriate cache entry cannot be found, processing of the        Internal-Class PDU is halted.  Otherwise:   (2)  The cache information is extracted, and removed from the cache.   (3)  If the original incoming management target information indicates        an SNMP version which does not support Report PDUs, processing        of the Internal-Class PDU is halted.Levi, et al.                Standards Track                    [Page 24]

RFC 2573                   SNMP Applications                  April 1999   (4)  The proxy forwarder calls the Dispatcher using the        returnResponsePdu abstract service interface.  Parameters are:     -  The messageProcessingModel indicates the Message Processing        Model by which the original incoming message was processed.     -  The securityModel is that of the original incoming management        target extracted from the cache.     -  The securityName is that of the original incoming management        target extracted from the cache.     -  The securityLevel is that of the original incoming management        target extracted from the cache.     -  The contextEngineID is the value extracted from the cache.     -  The contextName is the value extracted from the cache.     -  The pduVersion indicates the version of the PDU to be returned.     -  The PDU is unused.     -  The maxSizeResponseScopedPDU is a local value indicating the        maximum size of a ScopedPDU that the application can accept.     -  The stateReference is the value extracted from the cache.     -  The statusInformation contains values specific to the Internal-        Class PDU type (for example, for a Report PDU, the        statusInformation contains the contextEngineID, contextName,        counter OID, and counter value received in the incoming Report        PDU).3.5.2.  Notification Forwarding   A proxy forwarder receives notifications in the same manner as a   notification receiver application, using the processPdu abstract   service interface.  The following procedure is used when a   notification is received:   (1)  The incoming management target information received from the        processPdu interface is translated into outgoing management        target information.  Note that this translation may vary for        different values of contextEngineID and/or contextName.  The        translation may result in multiple management targets.Levi, et al.                Standards Track                    [Page 25]

RFC 2573                   SNMP Applications                  April 1999   (2)  If appropriate outgoing management target information cannot be        found and the notification was an Unconfirmed-Class PDU,        processing of the notification is halted.  If appropriate        outgoing management target information cannot be found and the        notification was a Confirmed-Class PDU, the proxy forwarder        increments the snmpProxyDrops object, and calls the Dispatcher        using the returnResponsePdu abstract service interface.  The        parameters are:     -  The messageProcessingModel is the received value.     -  The securityModel is the received value.     -  The securityName is the received value.     -  The securityLevel is the received value.     -  The contextEngineID is the received value.     -  The contextName is the received value.     -  The pduVersion is the received value.     -  The PDU is an undefined and unused value.     -  The maxSizeResponseScopedPDU is a local value indicating the        maximum size of a ScopedPDU that the application can accept.     -  The stateReference is the received value.     -  The statusInformation indicates that an error occurred and that        a Report message should be generated.   Processing of the message stops at this point.  Otherwise,   (3)  The proxy forwarder generates a notification using the        procedures described in the preceding section on Notification        Originators, with the following exceptions:     -  The contextEngineID and contextName values from the original        received notification are used.     -  The outgoing management targets previously determined are used.     -  No filtering mechanisms are applied.Levi, et al.                Standards Track                    [Page 26]

RFC 2573                   SNMP Applications                  April 1999     -  The variable-bindings from the original received notification        are used, rather than retrieving variable-bindings from local        MIB instrumentation.  In particular, no access-control is        applied to these variable-bindings.     -  If the original notification contains a Confirmed-Class PDU,        then any outgoing management targets, for which the outgoing        SNMP version does not support and PDU types which are both        Notification-Class and Confirmed-Class PDUs, will not be used        when generating the forwarded notifications.     -  If, for any of the outgoing management targets, the incoming        SNMP version and the outgoing SNMP version support different PDU        versions, the proxy forwarder may need to perform a translation        on the PDU.  (A method for performing such a translation is        described in [COEX].)   (4)  If the original received notification contains an Unconfirmed-        Class PDU, processing of the notification is now completed.        Otherwise, the original received notification must contain a        Confirmed-Class PDU, and processing continues.   (5)  If the forwarded notifications included any Confirmed-Class        PDUs, processing continues when the procedures described in the        section for Notification Originators determine that either:     -  None of the generated notifications containing Confirmed-Class        PDUs have been successfully acknowledged within the longest of        the time intervals, in which case processing of the original        notification is halted, or,     -  At least one of the generated notifications containing        Confirmed-Class PDUs is successfully acknowledged, in which case        a response to the original received notification containing an        Confirmed-Class PDU is generated as described in the following        steps.   (6)  A Response-Class PDU is constructed, using the values of        request-id and variable-bindings from the original received        Notification-Class PDU, and error-status and error-index values        of 0.   (7)  The Dispatcher is called using the returnResponsePdu abstract        service interface.  Parameters are:     -  The messageProcessingModel is the originally received value.     -  The securityModel is the originally received value.Levi, et al.                Standards Track                    [Page 27]

RFC 2573                   SNMP Applications                  April 1999     -  The securityName is the originally received value.     -  The securityLevel is the originally received value.     -  The contextEngineID is the originally received value.     -  The contextName is the originally received value.     -  The pduVersion indicates the version of the PDU constructed in        step (6) above.     -  The PDU is the value constructed in step (6) above.     -  The maxSizeResponseScopedPDU is a local value indicating the        maximum size of a ScopedPDU that the application can accept.     -  The stateReference is the originally received value.     -  The statusInformation indicates that no error occurred and that        a Response-Class PDU message should be generated.4.  The Structure of the MIB Modules   There are three separate MIB modules described in this document, the   management target MIB, the notification MIB, and the proxy MIB.  The   following sections describe the structure of these three MIB modules.   The use of these MIBs by particular types of applications is   described later in this document:     -  The use of the management target MIB and the notification MIB in        notification originator applications is described insection 6.     -  The use of the notification MIB for filtering notifications in        notification originator applications is described insection 7.     -  The use of the management target MIB and the proxy MIB in proxy        forwarding applications is described insection 8.4.1.  The Management Target MIB Module   The SNMP-TARGET-MIB module contains objects for defining management   targets.  It consists of two tables and conformance/compliance   statements.Levi, et al.                Standards Track                    [Page 28]

RFC 2573                   SNMP Applications                  April 1999   The first table, the snmpTargetAddrTable, contains information about   transport domains and addresses.  It also contains an object,   snmpTargetAddrTagList, which provides a mechanism for grouping   entries.   The second table, the snmpTargetParamsTable, contains information   about SNMP version and security information to be used when sending   messages to particular transport domains and addresses.   The Management Target MIB is intended to provide a general-purpose   mechanism for specifying transport address, and for specifying   parameters of SNMP messages generated by an SNMP entity.  It is used   within this document for generation of notifications and for proxy   forwarding.  However, it may be used for other purposes.  If another   document makes use of this MIB, that document is responsible for   specifying how it is used.  For example, [COEX] uses this MIB for   source address validation of SNMPv1 messages.4.1.1.  Tag Lists   The snmpTargetAddrTagList object is used for grouping entries in the   snmpTargetAddrTable.  The value of this object contains a list of tag   values which are used to select target addresses to be used for a   particular operation.   A tag value, which may also be used in MIB objects other than   snmpTargetAddrTagList, is an arbitrary string of octets, but may not   contain a delimiter character.  Delimiter characters are defined to   be one of the following characters:     -  An ASCII space character (0x20).     -  An ASCII TAB character (0x09).     -  An ASCII carriage return (CR) character (0x0D).     -  An ASCII line feed (LF) character (0x0B).   In addition, a tag value may not have a zero length.  Generally, a   particular MIB object may contain either     -  a single tag value, in which case the value of the MIB object        may not contain a delimiter character, or:     -  a MIB object may contain a list of tag values, separated by        single delimiter characters.Levi, et al.                Standards Track                    [Page 29]

RFC 2573                   SNMP Applications                  April 1999   For a list of tag values, these constraints imply certain   restrictions on the value of a MIB object:     -  There cannot be a leading or trailing delimiter character.     -  There cannot be multiple adjacent delimiter characters.4.1.2.  Definitions   SNMP-TARGET-MIB DEFINITIONS ::= BEGIN   IMPORTS       MODULE-IDENTITY,       OBJECT-TYPE,       snmpModules,       Counter32,       Integer32           FROM SNMPv2-SMI       TEXTUAL-CONVENTION,       TDomain,       TAddress,       TimeInterval,       RowStatus,       StorageType,       TestAndIncr           FROM SNMPv2-TC       SnmpSecurityModel,       SnmpMessageProcessingModel,       SnmpSecurityLevel,       SnmpAdminString           FROM SNMP-FRAMEWORK-MIB       MODULE-COMPLIANCE,       OBJECT-GROUP           FROM SNMPv2-CONF;   snmpTargetMIB MODULE-IDENTITY       LAST-UPDATED "9808040000Z"       ORGANIZATION "IETF SNMPv3 Working Group"       CONTACT-INFO           "WG-email:   snmpv3@lists.tislabs.com            Subscribe:  majordomo@lists.tislabs.com                        In message body:  subscribe snmpv3            Chair:      Russ MundyLevi, et al.                Standards Track                    [Page 30]

RFC 2573                   SNMP Applications                  April 1999                        Trusted Information Systems            Postal:     3060 Washington Rd                        Glenwood MD 21738                        USA            EMail:      mundy@tislabs.com            Phone:      +1-301-854-6889            Co-editor:  David B. Levi                        SNMP Research, Inc.            Postal:     3001 Kimberlin Heights Road                        Knoxville, TN 37920-9716            EMail:      levi@snmp.com            Phone:      +1 423 573 1434            Co-editor:  Paul Meyer                        Secure Computing Corporation            Postal:     2675 Long Lake Road                        Roseville, MN 55113            EMail:      paul_meyer@securecomputing.com            Phone:      +1 651 628 1592            Co-editor:  Bob Stewart                        Cisco Systems, Inc.            Postal:     170 West Tasman Drive                        San Jose, CA 95134-1706            EMail:      bstewart@cisco.com            Phone:      +1 603 654 2686"       DESCRIPTION           "This MIB module defines MIB objects which provide            mechanisms to remotely configure the parameters used            by an SNMP entity for the generation of SNMP messages."       REVISION    "9808040000Z"       DESCRIPTION "Clarifications, published asRFC2573."       REVISION    "9707140000Z"       DESCRIPTION "The initial revision, published asRFC2273."       ::= { snmpModules 12 }   snmpTargetObjects       OBJECT IDENTIFIER ::= { snmpTargetMIB 1 }   snmpTargetConformance   OBJECT IDENTIFIER ::= { snmpTargetMIB 3 }   SnmpTagValue ::= TEXTUAL-CONVENTION       DISPLAY-HINT "255a"       STATUS       current       DESCRIPTION           "An octet string containing a tag value.            Tag values are preferably in human-readable form.Levi, et al.                Standards Track                    [Page 31]

RFC 2573                   SNMP Applications                  April 1999            To facilitate internationalization, this information            is represented using the ISO/IEC IS 10646-1 character            set, encoded as an octet string using the UTF-8            character encoding scheme described inRFC 2279.            Since additional code points are added by amendments            to the 10646 standard from time to time,            implementations must be prepared to encounter any code            point from 0x00000000 to 0x7fffffff.            The use of control codes should be avoided, and certain            control codes are not allowed as described below.            For code points not directly supported by user            interface hardware or software, an alternative means            of entry and display, such as hexadecimal, may be            provided.            For information encoded in 7-bit US-ASCII, the UTF-8            representation is identical to the US-ASCII encoding.            Note that when this TC is used for an object that            is used or envisioned to be used as an index, then a            SIZE restriction must be specified so that the number            of sub-identifiers for any object instance does not            exceed the limit of 128, as defined by [RFC1905].            An object of this type contains a single tag value            which is used to select a set of entries in a table.            A tag value is an arbitrary string of octets, but            may not contain a delimiter character.  Delimiter            characters are defined to be one of the following:                -  An ASCII space character (0x20).                -  An ASCII TAB character (0x09).                -  An ASCII carriage return (CR) character (0x0D).                -  An ASCII line feed (LF) character (0x0B).            Delimiter characters are used to separate tag values            in a tag list.  An object of this type may only            contain a single tag value, and so delimiter            characters are not allowed in a value of this type.            Some examples of valid tag values are:Levi, et al.                Standards Track                    [Page 32]

RFC 2573                   SNMP Applications                  April 1999                - 'acme'                - 'router'                - 'host'            The use of a tag value to select table entries is            application and MIB specific."       SYNTAX       OCTET STRING (SIZE (0..255))   SnmpTagList ::= TEXTUAL-CONVENTION       DISPLAY-HINT "255a"       STATUS       current       DESCRIPTION           "An octet string containing a list of tag values.            Tag values are preferably in human-readable form.            To facilitate internationalization, this information            is represented using the ISO/IEC IS 10646-1 character            set, encoded as an octet string using the UTF-8            character encoding scheme described inRFC 2279.            Since additional code points are added by amendments            to the 10646 standard from time to time,            implementations must be prepared to encounter any code            point from 0x00000000 to 0x7fffffff.            The use of control codes should be avoided, except as            described below.            For code points not directly supported by user            interface hardware or software, an alternative means            of entry and display, such as hexadecimal, may be            provided.            For information encoded in 7-bit US-ASCII, the UTF-8            representation is identical to the US-ASCII encoding.            An object of this type contains a list of tag values            which are used to select a set of entries in a table.            A tag value is an arbitrary string of octets, but            may not contain a delimiter character.  Delimiter            characters are defined to be one of the following:                -  An ASCII space character (0x20).                -  An ASCII TAB character (0x09).Levi, et al.                Standards Track                    [Page 33]

RFC 2573                   SNMP Applications                  April 1999                -  An ASCII carriage return (CR) character (0x0D).                -  An ASCII line feed (LF) character (0x0B).            Delimiter characters are used to separate tag values            in a tag list.  Only a single delimiter character may            occur between two tag values.  A tag value may not            have a zero length.  These constraints imply certain            restrictions on the contents of this object:                - There cannot be a leading or trailing delimiter                  character.                - There cannot be multiple adjacent delimiter                  characters.            Some examples of valid tag lists are:                - An empty string                - 'acme router'                - 'host managerStation'            Note that although a tag value may not have a length of            zero, an empty string is still valid.  This indicates            an empty list (i.e. there are no tag values in the list).            The use of the tag list to select table entries is            application and MIB specific.  Typically, an application            will provide one or more tag values, and any entry            which contains some combination of these tag values            will be selected."       SYNTAX       OCTET STRING (SIZE (0..255))   --   --   -- The snmpTargetObjects group   --   --   snmpTargetSpinLock OBJECT-TYPE       SYNTAX      TestAndIncr       MAX-ACCESS  read-write       STATUS      current       DESCRIPTION           "This object is used to facilitate modification of table            entries in the SNMP-TARGET-MIB module by multipleLevi, et al.                Standards Track                    [Page 34]

RFC 2573                   SNMP Applications                  April 1999            managers.  In particular, it is useful when modifying            the value of the snmpTargetAddrTagList object.            The procedure for modifying the snmpTargetAddrTagList            object is as follows:                1.  Retrieve the value of snmpTargetSpinLock and                    of snmpTargetAddrTagList.                2.  Generate a new value for snmpTargetAddrTagList.                3.  Set the value of snmpTargetSpinLock to the                    retrieved value, and the value of                    snmpTargetAddrTagList to the new value.  If                    the set fails for the snmpTargetSpinLock                    object, go back to step 1."       ::= { snmpTargetObjects 1 }   snmpTargetAddrTable OBJECT-TYPE       SYNTAX      SEQUENCE OF SnmpTargetAddrEntry       MAX-ACCESS  not-accessible       STATUS      current       DESCRIPTION           "A table of transport addresses to be used in the generation            of SNMP messages."       ::= { snmpTargetObjects 2 }   snmpTargetAddrEntry OBJECT-TYPE       SYNTAX      SnmpTargetAddrEntry       MAX-ACCESS  not-accessible       STATUS      current       DESCRIPTION           "A transport address to be used in the generation            of SNMP operations.            Entries in the snmpTargetAddrTable are created and            deleted using the snmpTargetAddrRowStatus object."       INDEX { IMPLIED snmpTargetAddrName }       ::= { snmpTargetAddrTable 1 }   SnmpTargetAddrEntry ::= SEQUENCE {       snmpTargetAddrName         SnmpAdminString,       snmpTargetAddrTDomain      TDomain,       snmpTargetAddrTAddress     TAddress,       snmpTargetAddrTimeout      TimeInterval,       snmpTargetAddrRetryCount   Integer32,       snmpTargetAddrTagList      SnmpTagList,       snmpTargetAddrParams       SnmpAdminString,Levi, et al.                Standards Track                    [Page 35]

RFC 2573                   SNMP Applications                  April 1999       snmpTargetAddrStorageType  StorageType,       snmpTargetAddrRowStatus    RowStatus   }   snmpTargetAddrName OBJECT-TYPE       SYNTAX      SnmpAdminString (SIZE(1..32))       MAX-ACCESS  not-accessible       STATUS      current       DESCRIPTION           "The locally arbitrary, but unique identifier associated            with this snmpTargetAddrEntry."       ::= { snmpTargetAddrEntry 1 }   snmpTargetAddrTDomain OBJECT-TYPE       SYNTAX      TDomain       MAX-ACCESS  read-create       STATUS      current       DESCRIPTION           "This object indicates the transport type of the address            contained in the snmpTargetAddrTAddress object."       ::= { snmpTargetAddrEntry 2 }   snmpTargetAddrTAddress OBJECT-TYPE       SYNTAX      TAddress       MAX-ACCESS  read-create       STATUS      current       DESCRIPTION           "This object contains a transport address.  The format of            this address depends on the value of the            snmpTargetAddrTDomain object."       ::= { snmpTargetAddrEntry 3 }   snmpTargetAddrTimeout OBJECT-TYPE       SYNTAX      TimeInterval       MAX-ACCESS  read-create       STATUS      current       DESCRIPTION           "This object should reflect the expected maximum round            trip time for communicating with the transport address            defined by this row.  When a message is sent to this            address, and a response (if one is expected) is not            received within this time period, an implementation            may assume that the response will not be delivered.            Note that the time interval that an application waits            for a response may actually be derived from the value            of this object.  The method for deriving the actual time            interval is implementation dependent.  One such methodLevi, et al.                Standards Track                    [Page 36]

RFC 2573                   SNMP Applications                  April 1999            is to derive the expected round trip time based on a            particular retransmission algorithm and on the number            of timeouts which have occurred.  The type of message may            also be considered when deriving expected round trip            times for retransmissions.  For example, if a message is            being sent with a securityLevel that indicates both            authentication and privacy, the derived value may be            increased to compensate for extra processing time spent            during authentication and encryption processing."       DEFVAL { 1500 }       ::= { snmpTargetAddrEntry 4 }   snmpTargetAddrRetryCount OBJECT-TYPE       SYNTAX      Integer32 (0..255)       MAX-ACCESS  read-create       STATUS      current       DESCRIPTION           "This object specifies a default number of retries to be            attempted when a response is not received for a generated            message.  An application may provide its own retry count,            in which case the value of this object is ignored."       DEFVAL { 3 }       ::= { snmpTargetAddrEntry 5 }   snmpTargetAddrTagList OBJECT-TYPE       SYNTAX      SnmpTagList       MAX-ACCESS  read-create       STATUS      current       DESCRIPTION           "This object contains a list of tag values which are            used to select target addresses for a particular            operation."       DEFVAL { "" }       ::= { snmpTargetAddrEntry 6 }   snmpTargetAddrParams OBJECT-TYPE       SYNTAX      SnmpAdminString (SIZE(1..32))       MAX-ACCESS  read-create       STATUS      current       DESCRIPTION           "The value of this object identifies an entry in the            snmpTargetParamsTable.  The identified entry            contains SNMP parameters to be used when generating            messages to be sent to this transport address."       ::= { snmpTargetAddrEntry 7 }   snmpTargetAddrStorageType OBJECT-TYPE       SYNTAX      StorageTypeLevi, et al.                Standards Track                    [Page 37]

RFC 2573                   SNMP Applications                  April 1999       MAX-ACCESS  read-create       STATUS      current       DESCRIPTION           "The storage type for this conceptual row."       DEFVAL { nonVolatile }       ::= { snmpTargetAddrEntry 8 }   snmpTargetAddrRowStatus OBJECT-TYPE       SYNTAX      RowStatus       MAX-ACCESS  read-create       STATUS      current       DESCRIPTION           "The status of this conceptual row.            To create a row in this table, a manager must            set this object to either createAndGo(4) or            createAndWait(5).            Until instances of all corresponding columns are            appropriately configured, the value of the            corresponding instance of the snmpTargetAddrRowStatus            column is 'notReady'.            In particular, a newly created row cannot be made            active until the corresponding instances of            snmpTargetAddrTDomain, snmpTargetAddrTAddress, and            snmpTargetAddrParams have all been set.            The following objects may not be modified while the            value of this object is active(1):                - snmpTargetAddrTDomain                - snmpTargetAddrTAddress            An attempt to set these objects while the value of            snmpTargetAddrRowStatus is active(1) will result in            an inconsistentValue error."       ::= { snmpTargetAddrEntry 9 }   snmpTargetParamsTable OBJECT-TYPE       SYNTAX      SEQUENCE OF SnmpTargetParamsEntry       MAX-ACCESS  not-accessible       STATUS      current       DESCRIPTION           "A table of SNMP target information to be used            in the generation of SNMP messages."       ::= { snmpTargetObjects 3 }   snmpTargetParamsEntry OBJECT-TYPE       SYNTAX      SnmpTargetParamsEntryLevi, et al.                Standards Track                    [Page 38]

RFC 2573                   SNMP Applications                  April 1999       MAX-ACCESS  not-accessible       STATUS      current       DESCRIPTION           "A set of SNMP target information.            Entries in the snmpTargetParamsTable are created and            deleted using the snmpTargetParamsRowStatus object."       INDEX { IMPLIED snmpTargetParamsName }       ::= { snmpTargetParamsTable 1 }   SnmpTargetParamsEntry ::= SEQUENCE {       snmpTargetParamsName           SnmpAdminString,       snmpTargetParamsMPModel        SnmpMessageProcessingModel,       snmpTargetParamsSecurityModel  SnmpSecurityModel,       snmpTargetParamsSecurityName   SnmpAdminString,       snmpTargetParamsSecurityLevel  SnmpSecurityLevel,       snmpTargetParamsStorageType    StorageType,       snmpTargetParamsRowStatus      RowStatus   }   snmpTargetParamsName OBJECT-TYPE       SYNTAX      SnmpAdminString (SIZE(1..32))       MAX-ACCESS  not-accessible       STATUS      current       DESCRIPTION           "The locally arbitrary, but unique identifier associated            with this snmpTargetParamsEntry."       ::= { snmpTargetParamsEntry 1 }   snmpTargetParamsMPModel OBJECT-TYPE       SYNTAX      SnmpMessageProcessingModel       MAX-ACCESS  read-create       STATUS      current       DESCRIPTION           "The Message Processing Model to be used when generating            SNMP messages using this entry."       ::= { snmpTargetParamsEntry 2 }   snmpTargetParamsSecurityModel OBJECT-TYPE       SYNTAX      SnmpSecurityModel (1..2147483647)       MAX-ACCESS  read-create       STATUS      current       DESCRIPTION           "The Security Model to be used when generating SNMP             messages using this entry.  An implementation may             choose to return an inconsistentValue error if an             attempt is made to set this variable to a value             for a security model which the implementation doesLevi, et al.                Standards Track                    [Page 39]

RFC 2573                   SNMP Applications                  April 1999             not support."       ::= { snmpTargetParamsEntry 3 }   snmpTargetParamsSecurityName OBJECT-TYPE       SYNTAX      SnmpAdminString       MAX-ACCESS  read-create       STATUS      current       DESCRIPTION           "The securityName which identifies the Principal on            whose behalf SNMP messages will be generated using            this entry."       ::= { snmpTargetParamsEntry 4 }   snmpTargetParamsSecurityLevel OBJECT-TYPE       SYNTAX      SnmpSecurityLevel       MAX-ACCESS  read-create       STATUS      current       DESCRIPTION           "The Level of Security to be used when generating            SNMP messages using this entry."       ::= { snmpTargetParamsEntry 5 }   snmpTargetParamsStorageType OBJECT-TYPE       SYNTAX      StorageType       MAX-ACCESS  read-create       STATUS      current       DESCRIPTION           "The storage type for this conceptual row."       DEFVAL { nonVolatile }       ::= { snmpTargetParamsEntry 6 }   snmpTargetParamsRowStatus OBJECT-TYPE       SYNTAX      RowStatus       MAX-ACCESS  read-create       STATUS      current       DESCRIPTION           "The status of this conceptual row.            To create a row in this table, a manager must            set this object to either createAndGo(4) or            createAndWait(5).            Until instances of all corresponding columns are            appropriately configured, the value of the            corresponding instance of the snmpTargetParamsRowStatus            column is 'notReady'.            In particular, a newly created row cannot be madeLevi, et al.                Standards Track                    [Page 40]

RFC 2573                   SNMP Applications                  April 1999            active until the corresponding            snmpTargetParamsMPModel,            snmpTargetParamsSecurityModel,            snmpTargetParamsSecurityName,            and snmpTargetParamsSecurityLevel have all been set.            The following objects may not be modified while the            value of this object is active(1):                - snmpTargetParamsMPModel                - snmpTargetParamsSecurityModel                - snmpTargetParamsSecurityName                - snmpTargetParamsSecurityLevel            An attempt to set these objects while the value of            snmpTargetParamsRowStatus is active(1) will result in            an inconsistentValue error."       ::= { snmpTargetParamsEntry 7 }   snmpUnavailableContexts OBJECT-TYPE       SYNTAX       Counter32       MAX-ACCESS   read-only       STATUS       current       DESCRIPTION           "The total number of packets received by the SNMP            engine which were dropped because the context            contained in the message was unavailable."       ::= { snmpTargetObjects 4 }   snmpUnknownContexts OBJECT-TYPE       SYNTAX       Counter32       MAX-ACCESS   read-only       STATUS       current       DESCRIPTION           "The total number of packets received by the SNMP            engine which were dropped because the context            contained in the message was unknown."       ::= { snmpTargetObjects 5 }   --   --   -- Conformance information   --   --   snmpTargetCompliances OBJECT IDENTIFIER ::=                                           { snmpTargetConformance 1 }   snmpTargetGroups      OBJECT IDENTIFIER ::=                                           { snmpTargetConformance 2 }   --Levi, et al.                Standards Track                    [Page 41]

RFC 2573                   SNMP Applications                  April 1999   --   -- Compliance statements   --   --   snmpTargetCommandResponderCompliance MODULE-COMPLIANCE       STATUS      current       DESCRIPTION           "The compliance statement for SNMP entities which include            a command responder application."       MODULE -- This Module           MANDATORY-GROUPS { snmpTargetCommandResponderGroup }       ::= { snmpTargetCompliances 1 }   snmpTargetBasicGroup OBJECT-GROUP       OBJECTS {           snmpTargetSpinLock,           snmpTargetAddrTDomain,           snmpTargetAddrTAddress,           snmpTargetAddrTagList,           snmpTargetAddrParams,           snmpTargetAddrStorageType,           snmpTargetAddrRowStatus,           snmpTargetParamsMPModel,           snmpTargetParamsSecurityModel,           snmpTargetParamsSecurityName,           snmpTargetParamsSecurityLevel,           snmpTargetParamsStorageType,           snmpTargetParamsRowStatus       }       STATUS      current       DESCRIPTION           "A collection of objects providing basic remote            configuration of management targets."       ::= { snmpTargetGroups 1 }   snmpTargetResponseGroup OBJECT-GROUP       OBJECTS {           snmpTargetAddrTimeout,           snmpTargetAddrRetryCount       }       STATUS      current       DESCRIPTION           "A collection of objects providing remote configuration            of management targets for applications which generate            SNMP messages for which a response message would be            expected."       ::= { snmpTargetGroups 2 }Levi, et al.                Standards Track                    [Page 42]

RFC 2573                   SNMP Applications                  April 1999   snmpTargetCommandResponderGroup OBJECT-GROUP       OBJECTS {           snmpUnavailableContexts,           snmpUnknownContexts       }       STATUS      current       DESCRIPTION           "A collection of objects required for command responder            applications, used for counting error conditions."       ::= { snmpTargetGroups 3 }   END4.2.  The Notification MIB Module   The SNMP-NOTIFICATION-MIB module contains objects for the remote   configuration of the parameters used by an SNMP entity for the   generation of notifications.  It consists of three tables and   conformance/compliance statements.  The first table, the   snmpNotifyTable, contains entries which select which entries in the   snmpTargetAddrTable should be used for generating notifications, and   the type of notifications to be generated.   The second table sparsely augments the snmpTargetAddrTable with an   object which is used to associate a set of filters with a particular   management target.   The third table defines filters which are used to limit the number of   notifications which are generated using particular management   targets.4.2.1.  Definitions   SNMP-NOTIFICATION-MIB DEFINITIONS ::= BEGIN   IMPORTS       MODULE-IDENTITY,       OBJECT-TYPE,       snmpModules           FROM SNMPv2-SMI       RowStatus,       StorageType           FROM SNMPv2-TC       SnmpAdminString           FROM SNMP-FRAMEWORK-MIBLevi, et al.                Standards Track                    [Page 43]

RFC 2573                   SNMP Applications                  April 1999       SnmpTagValue,       snmpTargetParamsName           FROM SNMP-TARGET-MIB       MODULE-COMPLIANCE,       OBJECT-GROUP           FROM SNMPv2-CONF;   snmpNotificationMIB MODULE-IDENTITY       LAST-UPDATED "9808040000Z"       ORGANIZATION "IETF SNMPv3 Working Group"       CONTACT-INFO           "WG-email:   snmpv3@lists.tislabs.com            Subscribe:  majordomo@lists.tislabs.com                        In message body:  subscribe snmpv3            Chair:      Russ Mundy                        Trusted Information Systems            Postal:     3060 Washington Rd                        Glenwood MD 21738                        USA            EMail:      mundy@tislabs.com            Phone:      +1-301-854-6889            Co-editor:  David B. Levi                        SNMP Research, Inc.            Postal:     3001 Kimberlin Heights Road                        Knoxville, TN 37920-9716            EMail:      levi@snmp.com            Phone:      +1 423 573 1434            Co-editor:  Paul Meyer                        Secure Computing Corporation            Postal:     2675 Long Lake Road                        Roseville, MN 55113            EMail:      paul_meyer@securecomputing.com            Phone:      +1 651 628 1592            Co-editor:  Bob Stewart                        Cisco Systems, Inc.            Postal:     170 West Tasman Drive                        San Jose, CA 95134-1706            EMail:      bstewart@cisco.com            Phone:      +1 603 654 2686"       DESCRIPTION           "This MIB module defines MIB objects which provide            mechanisms to remotely configure the parameters            used by an SNMP entity for the generation ofLevi, et al.                Standards Track                    [Page 44]

RFC 2573                   SNMP Applications                  April 1999            notifications."       REVISION    "9808040000Z"       DESCRIPTION "Clarifications, published asRFC2573"       REVISION    "9707140000Z"       DESCRIPTION "The initial revision, published asRFC2273."       ::= { snmpModules 13 }   snmpNotifyObjects       OBJECT IDENTIFIER ::=                                             { snmpNotificationMIB 1 }   snmpNotifyConformance   OBJECT IDENTIFIER ::=                                             { snmpNotificationMIB 3 }   --   --   -- The snmpNotifyObjects group   --   --   snmpNotifyTable OBJECT-TYPE       SYNTAX      SEQUENCE OF SnmpNotifyEntry       MAX-ACCESS  not-accessible       STATUS      current       DESCRIPTION           "This table is used to select management targets which should            receive notifications, as well as the type of notification            which should be sent to each selected management target."       ::= { snmpNotifyObjects 1 }   snmpNotifyEntry OBJECT-TYPE       SYNTAX      SnmpNotifyEntry       MAX-ACCESS  not-accessible       STATUS      current       DESCRIPTION           "An entry in this table selects a set of management targets            which should receive notifications, as well as the type of            notification which should be sent to each selected            management target.            Entries in the snmpNotifyTable are created and            deleted using the snmpNotifyRowStatus object."       INDEX { IMPLIED snmpNotifyName }       ::= { snmpNotifyTable 1 }   SnmpNotifyEntry ::= SEQUENCE {       snmpNotifyName         SnmpAdminString,       snmpNotifyTag          SnmpTagValue,       snmpNotifyType         INTEGER,Levi, et al.                Standards Track                    [Page 45]

RFC 2573                   SNMP Applications                  April 1999       snmpNotifyStorageType  StorageType,       snmpNotifyRowStatus    RowStatus   }   snmpNotifyName OBJECT-TYPE       SYNTAX      SnmpAdminString (SIZE(1..32))       MAX-ACCESS  not-accessible       STATUS      current       DESCRIPTION           "The locally arbitrary, but unique identifier associated            with this snmpNotifyEntry."       ::= { snmpNotifyEntry 1 }   snmpNotifyTag OBJECT-TYPE       SYNTAX      SnmpTagValue       MAX-ACCESS  read-create       STATUS      current       DESCRIPTION           "This object contains a single tag value which is used            to select entries in the snmpTargetAddrTable.  Any entry            in the snmpTargetAddrTable which contains a tag value            which is equal to the value of an instance of this            object is selected.  If this object contains a value            of zero length, no entries are selected."       DEFVAL { "" }       ::= { snmpNotifyEntry 2 }   snmpNotifyType OBJECT-TYPE       SYNTAX      INTEGER {                       trap(1),                       inform(2)                   }       MAX-ACCESS  read-create       STATUS      current       DESCRIPTION           "This object determines the type of notification to            be generated for entries in the snmpTargetAddrTable            selected by the corresponding instance of            snmpNotifyTag.  This value is only used when            generating notifications, and is ignored when            using the snmpTargetAddrTable for other purposes.            If the value of this object is trap(1), then any            messages generated for selected rows will contain            Unconfirmed-Class PDUs.            If the value of this object is inform(2), then any            messages generated for selected rows will containLevi, et al.                Standards Track                    [Page 46]

RFC 2573                   SNMP Applications                  April 1999            Confirmed-Class PDUs.            Note that if an SNMP entity only supports            generation of Unconfirmed-Class PDUs (and not            Confirmed-Class PDUs), then this object may be            read-only."       DEFVAL { trap }       ::= { snmpNotifyEntry 3 }   snmpNotifyStorageType OBJECT-TYPE       SYNTAX      StorageType       MAX-ACCESS  read-create       STATUS      current       DESCRIPTION           "The storage type for this conceptual row."       DEFVAL { nonVolatile }       ::= { snmpNotifyEntry 4 }   snmpNotifyRowStatus OBJECT-TYPE       SYNTAX      RowStatus       MAX-ACCESS  read-create       STATUS      current       DESCRIPTION           "The status of this conceptual row.            To create a row in this table, a manager must            set this object to either createAndGo(4) or            createAndWait(5)."       ::= { snmpNotifyEntry 5 }   snmpNotifyFilterProfileTable OBJECT-TYPE       SYNTAX      SEQUENCE OF SnmpNotifyFilterProfileEntry       MAX-ACCESS  not-accessible       STATUS      current       DESCRIPTION           "This table is used to associate a notification filter            profile with a particular set of target parameters."       ::= { snmpNotifyObjects 2 }   snmpNotifyFilterProfileEntry OBJECT-TYPE       SYNTAX      SnmpNotifyFilterProfileEntry       MAX-ACCESS  not-accessible       STATUS      current       DESCRIPTION           "An entry in this table indicates the name of the filter            profile to be used when generating notifications using            the corresponding entry in the snmpTargetParamsTable.            Entries in the snmpNotifyFilterProfileTable are createdLevi, et al.                Standards Track                    [Page 47]

RFC 2573                   SNMP Applications                  April 1999            and deleted using the snmpNotifyFilterProfileRowStatus            object."       INDEX { IMPLIED snmpTargetParamsName }       ::= { snmpNotifyFilterProfileTable 1 }   SnmpNotifyFilterProfileEntry ::= SEQUENCE {       snmpNotifyFilterProfileName         SnmpAdminString,       snmpNotifyFilterProfileStorType     StorageType,       snmpNotifyFilterProfileRowStatus    RowStatus   }   snmpNotifyFilterProfileName OBJECT-TYPE       SYNTAX      SnmpAdminString (SIZE(1..32))       MAX-ACCESS  read-create       STATUS      current       DESCRIPTION           "The name of the filter profile to be used when generating            notifications using the corresponding entry in the            snmpTargetAddrTable."       ::= { snmpNotifyFilterProfileEntry 1 }   snmpNotifyFilterProfileStorType OBJECT-TYPE       SYNTAX      StorageType       MAX-ACCESS  read-create       STATUS      current       DESCRIPTION           "The storage type of this conceptual row."       DEFVAL { nonVolatile }       ::= { snmpNotifyFilterProfileEntry 2 }   snmpNotifyFilterProfileRowStatus OBJECT-TYPE       SYNTAX      RowStatus       MAX-ACCESS  read-create       STATUS      current       DESCRIPTION           "The status of this conceptual row.            To create a row in this table, a manager must            set this object to either createAndGo(4) or            createAndWait(5).            Until instances of all corresponding columns are            appropriately configured, the value of the            corresponding instance of the            snmpNotifyFilterProfileRowStatus column is 'notReady'.            In particular, a newly created row cannot be made            active until the corresponding instance ofLevi, et al.                Standards Track                    [Page 48]

RFC 2573                   SNMP Applications                  April 1999            snmpNotifyFilterProfileName has been set."       ::= { snmpNotifyFilterProfileEntry 3 }   snmpNotifyFilterTable OBJECT-TYPE       SYNTAX      SEQUENCE OF SnmpNotifyFilterEntry       MAX-ACCESS  not-accessible       STATUS      current       DESCRIPTION           "The table of filter profiles.  Filter profiles are used            to determine whether particular management targets should            receive particular notifications.            When a notification is generated, it must be compared            with the filters associated with each management target            which is configured to receive notifications, in order to            determine whether it may be sent to each such management            target.            A more complete discussion of notification filtering            can be found insection 6. of [RFC2573]."       ::= { snmpNotifyObjects 3 }   snmpNotifyFilterEntry OBJECT-TYPE       SYNTAX      SnmpNotifyFilterEntry       MAX-ACCESS  not-accessible       STATUS      current       DESCRIPTION           "An element of a filter profile.            Entries in the snmpNotifyFilterTable are created and            deleted using the snmpNotifyFilterRowStatus object."       INDEX {         snmpNotifyFilterProfileName,               IMPLIED snmpNotifyFilterSubtree }       ::= { snmpNotifyFilterTable 1 }   SnmpNotifyFilterEntry ::= SEQUENCE {       snmpNotifyFilterSubtree           OBJECT IDENTIFIER,       snmpNotifyFilterMask              OCTET STRING,       snmpNotifyFilterType              INTEGER,       snmpNotifyFilterStorageType       StorageType,       snmpNotifyFilterRowStatus         RowStatus   }   snmpNotifyFilterSubtree OBJECT-TYPE       SYNTAX      OBJECT IDENTIFIER       MAX-ACCESS  not-accessible       STATUS      current       DESCRIPTIONLevi, et al.                Standards Track                    [Page 49]

RFC 2573                   SNMP Applications                  April 1999           "The MIB subtree which, when combined with the corresponding            instance of snmpNotifyFilterMask, defines a family of            subtrees which are included in or excluded from the            filter profile."       ::= { snmpNotifyFilterEntry 1 }   snmpNotifyFilterMask OBJECT-TYPE       SYNTAX      OCTET STRING (SIZE(0..16))       MAX-ACCESS  read-create       STATUS      current       DESCRIPTION           "The bit mask which, in combination with the corresponding            instance of snmpNotifyFilterSubtree, defines a family of            subtrees which are included in or excluded from the            filter profile.            Each bit of this bit mask corresponds to a            sub-identifier of snmpNotifyFilterSubtree, with the            most significant bit of the i-th octet of this octet            string value (extended if necessary, see below)            corresponding to the (8*i - 7)-th sub-identifier, and            the least significant bit of the i-th octet of this            octet string corresponding to the (8*i)-th            sub-identifier, where i is in the range 1 through 16.            Each bit of this bit mask specifies whether or not            the corresponding sub-identifiers must match when            determining if an OBJECT IDENTIFIER matches this            family of filter subtrees; a '1' indicates that an            exact match must occur; a '0' indicates 'wild card',            i.e., any sub-identifier value matches.            Thus, the OBJECT IDENTIFIER X of an object instance            is contained in a family of filter subtrees if, for            each sub-identifier of the value of            snmpNotifyFilterSubtree, either:              the i-th bit of snmpNotifyFilterMask is 0, or              the i-th sub-identifier of X is equal to the i-th              sub-identifier of the value of              snmpNotifyFilterSubtree.            If the value of this bit mask is M bits long and            there are more than M sub-identifiers in the            corresponding instance of snmpNotifyFilterSubtree,            then the bit mask is extended with 1's to be the            required length.Levi, et al.                Standards Track                    [Page 50]

RFC 2573                   SNMP Applications                  April 1999            Note that when the value of this object is the            zero-length string, this extension rule results in            a mask of all-1's being used (i.e., no 'wild card'),            and the family of filter subtrees is the one            subtree uniquely identified by the corresponding            instance of snmpNotifyFilterSubtree."       DEFVAL { ''H }       ::= { snmpNotifyFilterEntry 2 }   snmpNotifyFilterType OBJECT-TYPE       SYNTAX      INTEGER {                       included(1),                       excluded(2)                   }       MAX-ACCESS  read-create       STATUS      current       DESCRIPTION           "This object indicates whether the family of filter subtrees            defined by this entry are included in or excluded from a            filter.  A more detailed discussion of the use of this            object can be found insection 6. of [RFC2573]."       DEFVAL { included }       ::= { snmpNotifyFilterEntry 3 }   snmpNotifyFilterStorageType OBJECT-TYPE       SYNTAX      StorageType       MAX-ACCESS  read-create       STATUS      current       DESCRIPTION           "The storage type of this conceptual row."       DEFVAL { nonVolatile }       ::= { snmpNotifyFilterEntry 4 }   snmpNotifyFilterRowStatus OBJECT-TYPE       SYNTAX      RowStatus       MAX-ACCESS  read-create       STATUS      current       DESCRIPTION           "The status of this conceptual row.            To create a row in this table, a manager must            set this object to either createAndGo(4) or            createAndWait(5)."       ::= { snmpNotifyFilterEntry 5 }   --   --   -- Conformance informationLevi, et al.                Standards Track                    [Page 51]

RFC 2573                   SNMP Applications                  April 1999   --   --   snmpNotifyCompliances OBJECT IDENTIFIER ::=                                           { snmpNotifyConformance 1 }   snmpNotifyGroups      OBJECT IDENTIFIER ::=                                           { snmpNotifyConformance 2 }   --   --   -- Compliance statements   --   --   snmpNotifyBasicCompliance MODULE-COMPLIANCE       STATUS      current       DESCRIPTION           "The compliance statement for minimal SNMP entities which            implement only SNMP Unconfirmed-Class notifications and            read-create operations on only the snmpTargetAddrTable."       MODULE SNMP-TARGET-MIB           MANDATORY-GROUPS { snmpTargetBasicGroup }           OBJECT snmpTargetParamsMPModel           MIN-ACCESS    read-only           DESCRIPTION               "Create/delete/modify access is not required."           OBJECT snmpTargetParamsSecurityModel           MIN-ACCESS    read-only           DESCRIPTION               "Create/delete/modify access is not required."           OBJECT snmpTargetParamsSecurityName           MIN-ACCESS    read-only           DESCRIPTION               "Create/delete/modify access is not required."           OBJECT snmpTargetParamsSecurityLevel           MIN-ACCESS    read-only           DESCRIPTION               "Create/delete/modify access is not required."           OBJECT snmpTargetParamsStorageType           SYNTAX INTEGER {               readOnly(5)           }           MIN-ACCESS    read-only           DESCRIPTIONLevi, et al.                Standards Track                    [Page 52]

RFC 2573                   SNMP Applications                  April 1999               "Create/delete/modify access is not required.                Support of the values other(1), volatile(2),                nonVolatile(3), and permanent(4) is not required."           OBJECT snmpTargetParamsRowStatus           SYNTAX INTEGER {               active(1)           }           MIN-ACCESS    read-only           DESCRIPTION               "Create/delete/modify access to the                snmpTargetParamsTable is not required.                Support of the values notInService(2), notReady(3),                createAndGo(4), createAndWait(5), and destroy(6) is                not required."       MODULE -- This Module           MANDATORY-GROUPS { snmpNotifyGroup }           OBJECT snmpNotifyTag           MIN-ACCESS    read-only           DESCRIPTION               "Create/delete/modify access is not required."           OBJECT snmpNotifyType           SYNTAX INTEGER {               trap(1)           }           MIN-ACCESS    read-only           DESCRIPTION               "Create/delete/modify access is not required.                Support of the value notify(2) is not required."           OBJECT snmpNotifyStorageType           SYNTAX INTEGER {               readOnly(5)           }           MIN-ACCESS    read-only           DESCRIPTION               "Create/delete/modify access is not required.                Support of the values other(1), volatile(2),                nonVolatile(3), and permanent(4) is not required."           OBJECT snmpNotifyRowStatus           SYNTAX INTEGER {               active(1)           }           MIN-ACCESS    read-onlyLevi, et al.                Standards Track                    [Page 53]

RFC 2573                   SNMP Applications                  April 1999           DESCRIPTION               "Create/delete/modify access to the                snmpNotifyTable is not required.                Support of the values notInService(2), notReady(3),                createAndGo(4), createAndWait(5), and destroy(6) is                not required."       ::= { snmpNotifyCompliances 1 }   snmpNotifyBasicFiltersCompliance MODULE-COMPLIANCE       STATUS      current       DESCRIPTION           "The compliance statement for SNMP entities which implement            SNMP Unconfirmed-Class notifications with filtering, and            read-create operations on all related tables."       MODULE SNMP-TARGET-MIB           MANDATORY-GROUPS { snmpTargetBasicGroup }       MODULE -- This Module           MANDATORY-GROUPS { snmpNotifyGroup,                              snmpNotifyFilterGroup }       ::= { snmpNotifyCompliances 2 }   snmpNotifyFullCompliance MODULE-COMPLIANCE       STATUS      current       DESCRIPTION           "The compliance statement for SNMP entities which either            implement only SNMP Confirmed-Class notifications, or both            SNMP Unconfirmed-Class and Confirmed-Class notifications,            plus filtering and read-create operations on all related            tables."       MODULE SNMP-TARGET-MIB           MANDATORY-GROUPS { snmpTargetBasicGroup,                              snmpTargetResponseGroup }       MODULE -- This Module           MANDATORY-GROUPS { snmpNotifyGroup,                              snmpNotifyFilterGroup }       ::= { snmpNotifyCompliances 3 }   snmpNotifyGroup OBJECT-GROUP       OBJECTS {           snmpNotifyTag,           snmpNotifyType,           snmpNotifyStorageType,           snmpNotifyRowStatus       }       STATUS      current       DESCRIPTION           "A collection of objects for selecting which managementLevi, et al.                Standards Track                    [Page 54]

RFC 2573                   SNMP Applications                  April 1999            targets are used for generating notifications, and the            type of notification to be generated for each selected            management target."       ::= { snmpNotifyGroups 1 }   snmpNotifyFilterGroup OBJECT-GROUP       OBJECTS {           snmpNotifyFilterProfileName,           snmpNotifyFilterProfileStorType,           snmpNotifyFilterProfileRowStatus,           snmpNotifyFilterMask,           snmpNotifyFilterType,           snmpNotifyFilterStorageType,           snmpNotifyFilterRowStatus       }       STATUS      current       DESCRIPTION           "A collection of objects providing remote configuration            of notification filters."       ::= { snmpNotifyGroups 2 }   END4.3.  The Proxy MIB Module   The SNMP-PROXY-MIB module, which defines MIB objects that provide   mechanisms to remotely configure the parameters used by an SNMP   entity for proxy forwarding operations, contains a single table.   This table, snmpProxyTable, is used to define translations between   management targets for use when forwarding messages.4.3.1.  Definitions   SNMP-PROXY-MIB DEFINITIONS ::= BEGIN   IMPORTS       MODULE-IDENTITY,       OBJECT-TYPE,       snmpModules           FROM SNMPv2-SMI       RowStatus,       StorageType           FROM SNMPv2-TC       SnmpEngineID,       SnmpAdminString           FROM SNMP-FRAMEWORK-MIBLevi, et al.                Standards Track                    [Page 55]

RFC 2573                   SNMP Applications                  April 1999       SnmpTagValue           FROM SNMP-TARGET-MIB       MODULE-COMPLIANCE,       OBJECT-GROUP           FROM SNMPv2-CONF;   snmpProxyMIB MODULE-IDENTITY       LAST-UPDATED "9808040000Z"       ORGANIZATION "IETF SNMPv3 Working Group"       CONTACT-INFO           "WG-email:   snmpv3@lists.tislabs.com            Subscribe:  majordomo@lists.tislabs.com                        In message body:  subscribe snmpv3            Chair:      Russ Mundy                        Trusted Information Systems            Postal:     3060 Washington Rd                        Glenwood MD 21738                        USA            EMail:      mundy@tislabs.com            Phone:      +1-301-854-6889            Co-editor:  David B. Levi                        SNMP Research, Inc.            Postal:     3001 Kimberlin Heights Road                        Knoxville, TN 37920-9716            EMail:      levi@snmp.com            Phone:      +1 423 573 1434            Co-editor:  Paul Meyer                        Secure Computing Corporation            Postal:     2675 Long Lake Road                        Roseville, MN 55113            EMail:      paul_meyer@securecomputing.com            Phone:      +1 651 628 1592            Co-editor:  Bob Stewart                        Cisco Systems, Inc.            Postal:     170 West Tasman Drive                        San Jose, CA 95134-1706            EMail:      bstewart@cisco.com            Phone:      +1 603 654 2686"       DESCRIPTION           "This MIB module defines MIB objects which provide            mechanisms to remotely configure the parameters            used by a proxy forwarding application."       REVISION    "9808040000Z"Levi, et al.                Standards Track                    [Page 56]

RFC 2573                   SNMP Applications                  April 1999       DESCRIPTION "Clarifications, published asRFC2573."       REVISION    "9707140000Z"       DESCRIPTION "The initial revision, published asRFC2273."       ::= { snmpModules 14 }   snmpProxyObjects        OBJECT IDENTIFIER ::= { snmpProxyMIB 1 }   snmpProxyConformance    OBJECT IDENTIFIER ::= { snmpProxyMIB 3 }   --   --   -- The snmpProxyObjects group   --   --   snmpProxyTable OBJECT-TYPE       SYNTAX      SEQUENCE OF SnmpProxyEntry       MAX-ACCESS  not-accessible       STATUS      current       DESCRIPTION           "The table of translation parameters used by proxy forwarder            applications for forwarding SNMP messages."       ::= { snmpProxyObjects 2 }   snmpProxyEntry OBJECT-TYPE       SYNTAX      SnmpProxyEntry       MAX-ACCESS  not-accessible       STATUS      current       DESCRIPTION           "A set of translation parameters used by a proxy forwarder            application for forwarding SNMP messages.            Entries in the snmpProxyTable are created and deleted            using the snmpProxyRowStatus object."       INDEX { IMPLIED snmpProxyName }       ::= { snmpProxyTable 1 }   SnmpProxyEntry ::= SEQUENCE {       snmpProxyName               SnmpAdminString,       snmpProxyType               INTEGER,       snmpProxyContextEngineID    SnmpEngineID,       snmpProxyContextName        SnmpAdminString,       snmpProxyTargetParamsIn     SnmpAdminString,       snmpProxySingleTargetOut    SnmpAdminString,       snmpProxyMultipleTargetOut  SnmpTagValue,       snmpProxyStorageType        StorageType,       snmpProxyRowStatus          RowStatus   }Levi, et al.                Standards Track                    [Page 57]

RFC 2573                   SNMP Applications                  April 1999   snmpProxyName OBJECT-TYPE       SYNTAX      SnmpAdminString (SIZE(1..32))       MAX-ACCESS  not-accessible       STATUS      current       DESCRIPTION           "The locally arbitrary, but unique identifier associated            with this snmpProxyEntry."       ::= { snmpProxyEntry 1 }   snmpProxyType OBJECT-TYPE       SYNTAX      INTEGER {                       read(1),                       write(2),                       trap(3),                       inform(4)                   }       MAX-ACCESS  read-create       STATUS      current       DESCRIPTION           "The type of message that may be forwarded using            the translation parameters defined by this entry."       ::= { snmpProxyEntry 2 }   snmpProxyContextEngineID OBJECT-TYPE       SYNTAX      SnmpEngineID       MAX-ACCESS  read-create       STATUS      current       DESCRIPTION           "The contextEngineID contained in messages that            may be forwarded using the translation parameters            defined by this entry."       ::= { snmpProxyEntry 3 }   snmpProxyContextName OBJECT-TYPE       SYNTAX      SnmpAdminString       MAX-ACCESS  read-create       STATUS      current       DESCRIPTION           "The contextName contained in messages that may be            forwarded using the translation parameters defined            by this entry.            This object is optional, and if not supported, the            contextName contained in a message is ignored when            selecting an entry in the snmpProxyTable."       ::= { snmpProxyEntry 4 }   snmpProxyTargetParamsIn OBJECT-TYPELevi, et al.                Standards Track                    [Page 58]

RFC 2573                   SNMP Applications                  April 1999       SYNTAX      SnmpAdminString       MAX-ACCESS  read-create       STATUS      current       DESCRIPTION           "This object selects an entry in the snmpTargetParamsTable.            The selected entry is used to determine which row of the            snmpProxyTable to use for forwarding received messages."       ::= { snmpProxyEntry 5 }   snmpProxySingleTargetOut OBJECT-TYPE       SYNTAX      SnmpAdminString       MAX-ACCESS  read-create       STATUS      current       DESCRIPTION           "This object selects a management target defined in the            snmpTargetAddrTable (in the SNMP-TARGET-MIB).  The            selected target is defined by an entry in the            snmpTargetAddrTable whose index value (snmpTargetAddrName)            is equal to this object.            This object is only used when selection of a single            target is required (i.e. when forwarding an incoming            read or write request)."       ::= { snmpProxyEntry 6 }   snmpProxyMultipleTargetOut OBJECT-TYPE       SYNTAX      SnmpTagValue       MAX-ACCESS  read-create       STATUS      current       DESCRIPTION           "This object selects a set of management targets defined            in the snmpTargetAddrTable (in the SNMP-TARGET-MIB).            This object is only used when selection of multiple            targets is required (i.e. when forwarding an incoming            notification)."       ::= { snmpProxyEntry 7 }   snmpProxyStorageType OBJECT-TYPE       SYNTAX      StorageType       MAX-ACCESS  read-create       STATUS      current       DESCRIPTION           "The storage type of this conceptual row."       DEFVAL { nonVolatile }       ::= { snmpProxyEntry 8 }   snmpProxyRowStatus OBJECT-TYPELevi, et al.                Standards Track                    [Page 59]

RFC 2573                   SNMP Applications                  April 1999       SYNTAX      RowStatus       MAX-ACCESS  read-create       STATUS      current       DESCRIPTION           "The status of this conceptual row.            To create a row in this table, a manager must            set this object to either createAndGo(4) or            createAndWait(5).            The following objects may not be modified while the            value of this object is active(1):                - snmpProxyType                - snmpProxyContextEngineID                - snmpProxyContextName                - snmpProxyTargetParamsIn                - snmpProxySingleTargetOut                - snmpProxyMultipleTargetOut"       ::= { snmpProxyEntry 9 }   --   --   -- Conformance information   --   --   snmpProxyCompliances OBJECT IDENTIFIER ::=                                            { snmpProxyConformance 1 }   snmpProxyGroups      OBJECT IDENTIFIER ::=                                            { snmpProxyConformance 2 }   --   --   -- Compliance statements   --   --   snmpProxyCompliance MODULE-COMPLIANCE       STATUS      current       DESCRIPTION           "The compliance statement for SNMP entities which include            a proxy forwarding application."       MODULE SNMP-TARGET-MIB           MANDATORY-GROUPS { snmpTargetBasicGroup,                              snmpTargetResponseGroup }       MODULE -- This Module           MANDATORY-GROUPS { snmpProxyGroup }       ::= { snmpProxyCompliances 1 }Levi, et al.                Standards Track                    [Page 60]

RFC 2573                   SNMP Applications                  April 1999   snmpProxyGroup OBJECT-GROUP       OBJECTS {           snmpProxyType,           snmpProxyContextEngineID,           snmpProxyContextName,           snmpProxyTargetParamsIn,           snmpProxySingleTargetOut,           snmpProxyMultipleTargetOut,           snmpProxyStorageType,           snmpProxyRowStatus       }       STATUS      current       DESCRIPTION           "A collection of objects providing remote configuration of            management target translation parameters for use by            proxy forwarder applications."       ::= { snmpProxyGroups 3 }   END5.  Identification of Management Targets in Notification Originators   This section describes the mechanisms used by a notification   originator application when using the MIB module described in this   document to determine the set of management targets to be used when   generating a notification.   A notification originator uses each entry in the snmpNotifyTable to   find the management targets to be used for generating notifications.   Each active entry in this table identifies zero or more entries in   the snmpTargetAddrTable.  Any entry in the snmpTargetAddrTable whose   snmpTargetAddrTagList object contains a tag value which is equal to a   value of snmpNotifyTag is selected by the snmpNotifyEntry which   contains that instance of snmpNotifyTag.  Note that a particular   snmpTargetAddrEntry may be selected by multiple entries in the   snmpNotifyTable, resulting in multiple notifications being generated   using that snmpTargetAddrEntry.   Each snmpTargetAddrEntry contains a pointer to the   snmpTargetParamsTable (snmpTargetAddrParams).  This pointer selects a   set of SNMP parameters to be used for generating notifications.  If   the selected entry in the snmpTargetParamsTable does not exist, the   management target is not used to generate notifications.   The decision as to whether a notification should contain an   Unconfirmed-Class or a Confirmed-Class PDU is determined by the value   of the snmpNotifyType object.  If the value of this object is   trap(1), the notification should contain an Unconfirmed-Class PDU.Levi, et al.                Standards Track                    [Page 61]

RFC 2573                   SNMP Applications                  April 1999   If the value of this object is inform(2), then the notification   should contain a Confirmed-Class PDU, and the timeout time and number   of retries for the notification are the value of   snmpTargetAddrTimeout and snmpTargetAddrRetryCount.  Note that the   exception to these rules is when the snmpTargetParamsMPModel object   indicates an SNMP version which supports a different PDU version.  In   this case, the notification may be sent using a different PDU type   ([COEX] defines the PDU type in the case where the outgoing SNMP   version is SNMPv1).6.  Notification Filtering   This section describes the mechanisms used by a notification   originator application when using the MIB module described in this   document to filter generation of notifications.   A notification originator uses the snmpNotifyFilterTable to filter   notifications.  A notification filter profile may be associated with   a particular entry in the snmpTargetParamsTable.  The associated   filter profile is identified by an entry in the   snmpNotifyFilterProfileTable whose index is equal to the index of the   entry in the snmpTargetParamsTable.  If no such entry exists in the   snmpNotifyFilterProfileTable, no filtering is performed for that   management target.   If such an entry does exist, the value of snmpNotifyFilterProfileName   of the entry is compared with the corresponding portion of the index   of all active entries in the snmpNotifyFilterTable.  All such entries   for which this comparison results in an exact match are used for   filtering a notification generated using the associated   snmpTargetParamsEntry.  If no such entries exist, no filtering is   performed, and a notification may be sent to the management target.   Otherwise, if matching entries do exist, a notification may be sent   if the NOTIFICATION-TYPE OBJECT IDENTIFIER of the notification (this   is the value of the element of the variable bindings whose name is   snmpTrapOID.0, i.e., the second variable binding) is specifically   included, and none of the object instances to be included in the   variable-bindings of the notification are specifically excluded by   the matching entries.   Each set of snmpNotifyFilterTable entries is divided into two   collections of filter subtrees:  the included filter subtrees, and   the excluded filter subtrees.  The snmpNotifyFilterType object   defines the collection to which each matching entry belongs.Levi, et al.                Standards Track                    [Page 62]

RFC 2573                   SNMP Applications                  April 1999   To determine whether a particular notification name or object   instance is excluded by the set of matching entries, compare the   notification name's or object instance's OBJECT IDENTIFIER with each   of the matching entries.  For a notification name, if none match,   then the notification name is considered excluded, and the   notification should not be sent to this management target.  For an   object instance, if none match, the object instance is considered   included, and the notification may be sent to this management target.   If one or more match, then the notification name or object instance   is included or excluded, according to the value of   snmpNotifyFilterType in the entry whose value of   snmpNotifyFilterSubtree has the most sub-identifiers.  If multiple   entries match and have the same number of sub-identifiers, then the   lexicographically greatest instance of snmpNotifyFilterType among   those which match determines the inclusion or exclusion.   A notification name or object instance's OBJECT IDENTIFIER X matches   an entry in the snmpNotifyFilterTable when the number of sub-   identifiers in X is at least as many as in the value of   snmpNotifyFilterSubtree for the entry, and each sub-identifier in the   value of snmpNotifyFilterSubtree matches its corresponding sub-   identifier in X.  Two sub-identifiers match either if the   corresponding bit of snmpNotifyFilterMask is zero (the 'wild card'   value), or if the two sub-identifiers are equal.7.  Management Target Translation in Proxy Forwarder Applications   This section describes the mechanisms used by a proxy forwarder   application when using the MIB module described in this document to   translate incoming management target information into outgoing   management target information for the purpose of forwarding messages.   There are actually two mechanisms a proxy forwarder may use, one for   forwarding request messages, and one for forwarding notification   messages.7.1.  Management Target Translation for Request Forwarding   When forwarding request messages, the proxy forwarder will select a   single entry in the snmpProxyTable.  To select this entry, it will   perform the following comparisons:     -  The snmpProxyType must be read(1) if the request is a Read-        Class PDU.  The snmpProxyType must be write(2) if the request is        a Write-Class PDU.     -  The contextEngineID must equal the snmpProxyContextEngineID        object.Levi, et al.                Standards Track                    [Page 63]

RFC 2573                   SNMP Applications                  April 1999     -  If the snmpProxyContextName object is supported, it must equal        the contextName.     -  The snmpProxyTargetParamsIn object identifies an entry in the        snmpTargetParamsTable.  The messageProcessingModel,        securityLevel, security model, and securityName must match the        values of snmpTargetParamsMPModel,        snmpTargetParamsSecurityModel, snmpTargetParamsSecurityName, and        snmpTargetParamsSecurityLevel of the identified entry in the        snmpTargetParamsTable.   There may be multiple entries in the snmpProxyTable for which these   comparisons succeed.  The entry whose snmpProxyName has the   lexicographically smallest value and for which the comparisons   succeed will be selected by the proxy forwarder.   The outgoing management target information is identified by the value   of the snmpProxySingleTargetOut object of the selected entry.  This   object identifies an entry in the snmpTargetAddrTable.  The   identified entry in the snmpTargetAddrTable also contains a reference   to the snmpTargetParamsTable (snmpTargetAddrParams).  If either the   identified entry in the snmpTargetAddrTable does not exist, or the   identified entry in the snmpTargetParamsTable does not exist, then   this snmpProxyEntry does not identify valid forwarding information,   and the proxy forwarder should attempt to identify another row.   If there is no entry in the snmpProxyTable for which all of the   conditions above may be met, then there is no appropriate forwarding   information, and the proxy forwarder should take appropriate actions.   Otherwise, The snmpTargetAddrTDomain, snmpTargetAddrTAddress,   snmpTargetAddrTimeout, and snmpTargetRetryCount of the identified   snmpTargetAddrEntry, and the snmpTargetParamsMPModel,   snmpTargetParamsSecurityModel, snmpTargetParamsSecurityName, and   snmpTargetParamsSecurityLevel of the identified snmpTargetParamsEntry   are used as the destination management target.7.2.  Management Target Translation for Notification Forwarding   When forwarding notification messages, the proxy forwarder will   select multiple entries in the snmpProxyTable.  To select these   entries, it will perform the following comparisons:     -  The snmpProxyType must be trap(3) if the notification is an        Unconfirmed-Class PDU.  The snmpProxyType must be inform(4) if        the request is a Confirmed-Class PDU.Levi, et al.                Standards Track                    [Page 64]

RFC 2573                   SNMP Applications                  April 1999     -  The contextEngineID must equal the snmpProxyContextEngineID        object.     -  If the snmpProxyContextName object is supported, it must equal        the contextName.     -  The snmpProxyTargetParamsIn object identifies an entry in the        snmpTargetParamsTable.  The messageProcessingModel,        securityLevel, security model, and securityName must match the        values of snmpTargetParamsMPModel,        snmpTargetParamsSecurityModel, snmpTargetParamsSecurityName, and        snmpTargetParamsSecurityLevel of the identified entry in the        snmpTargetParamsTable.   All entries for which these conditions are met are selected.  The   snmpProxyMultipleTargetOut object of each such entry is used to   select a set of entries in the snmpTargetAddrTable.  Any   snmpTargetAddrEntry whose snmpTargetAddrTagList object contains a tag   value equal to the value of snmpProxyMultipleTargetOut, and whose   snmpTargetAddrParams object references an existing entry in the   snmpTargetParamsTable, is selected as a destination for the forwarded   notification.8.  Intellectual Property   The IETF takes no position regarding the validity or scope of any   intellectual property or other rights that might be claimed to   pertain to the implementation or use of the technology described in   this document or the extent to which any license under such rights   might or might not be available; neither does it represent that it   has made any effort to identify any such rights.  Information on the   IETF's procedures with respect to rights in standards-track and   standards-related documentation can be found inBCP-11.  Copies of   claims of rights made available for publication and any assurances of   licenses to be made available, or the result of an attempt made to   obtain a general license or permission for the use of such   proprietary rights by implementors or users of this specification can   be obtained from the IETF Secretariat.   The IETF invites any interested party to bring to its attention any   copyrights, patents or patent applications, 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.Levi, et al.                Standards Track                    [Page 65]

RFC 2573                   SNMP Applications                  April 19999.  Acknowledgments   This document is the result of the efforts of the SNMPv3 Working   Group.  Some special thanks are in order to the following SNMPv3 WG   members:     Harald Tveit Alvestrand (Maxware)     Dave Battle (SNMP Research, Inc.)     Alan Beard (Disney Worldwide Services)     Paul Berrevoets (SWI Systemware/Halcyon Inc.)     Martin Bjorklund (Ericsson)     Uri Blumenthal (IBM T.J. Watson Research Center)     Jeff Case (SNMP Research, Inc.)     John Curran (BBN)     Mike Daniele (Compaq Computer Corporation)     T. Max Devlin (Eltrax Systems)     John Flick (Hewlett Packard)     Rob Frye (MCI)     Wes Hardaker (U.C.Davis, Information Technology - D.C.A.S.)     David Harrington (Cabletron Systems Inc.)     Lauren Heintz (BMC Software, Inc.)     N.C. Hien (IBM T.J. Watson Research Center)     Michael Kirkham (InterWorking Labs, Inc.)     Dave Levi (SNMP Research, Inc.)     Louis A Mamakos (UUNET Technologies Inc.)     Joe Marzot (Nortel Networks)     Paul Meyer (Secure Computing Corporation)     Keith McCloghrie (Cisco Systems)     Bob Moore (IBM)     Russ Mundy (TIS Labs at Network Associates)     Bob Natale (ACE*COMM Corporation)     Mike O'Dell (UUNET Technologies Inc.)     Dave Perkins (DeskTalk)     Peter Polkinghorne (Brunel University)     Randy Presuhn (BMC Software, Inc.)     David Reeder (TIS Labs at Network Associates)     David Reid (SNMP Research, Inc.)     Aleksey Romanov (Quality Quorum)     Shawn Routhier (Epilogue)     Juergen Schoenwaelder (TU Braunschweig)     Bob Stewart (Cisco Systems)     Mike Thatcher (Independent Consultant)     Bert Wijnen (IBM T.J. Watson Research Center)   The document is based on recommendations of the IETF Security and   Administrative Framework Evolution for SNMP Advisory Team. Members of   that Advisory Team were:Levi, et al.                Standards Track                    [Page 66]

RFC 2573                   SNMP Applications                  April 1999     David Harrington (Cabletron Systems Inc.)     Jeff Johnson (Cisco Systems)     David Levi (SNMP Research Inc.)     John Linn (Openvision)     Russ Mundy (Trusted Information Systems) chair     Shawn Routhier (Epilogue)     Glenn Waters (Nortel)     Bert Wijnen (IBM T. J. Watson Research Center)   As recommended by the Advisory Team and the SNMPv3 Working Group   Charter, the design incorporates as much as practical from previous   RFCs and drafts. As a result, special thanks are due to the authors   of previous designs known as SNMPv2u and SNMPv2*:     Jeff Case (SNMP Research, Inc.)     David Harrington (Cabletron Systems Inc.)     David Levi (SNMP Research, Inc.)     Keith McCloghrie (Cisco Systems)     Brian O'Keefe (Hewlett Packard)     Marshall T. Rose (Dover Beach Consulting)     Jon Saperia (BGS Systems Inc.)     Steve Waldbusser (International Network Services)     Glenn W. Waters (Bell-Northern Research Ltd.)10.  Security Considerations   The SNMP applications described in this document typically have   direct access to MIB instrumentation.  Thus, it is very important   that these applications be strict in their application of access   control as described in this document.   In addition, there may be some types of notification generator   applications which, rather than accessing MIB instrumentation using   access control, will obtain MIB information through other means (such   as from a command line).  The implementors and users of such   applications must be responsible for not divulging MIB information   that normally would be inaccessible due to access control.   Finally, the MIBs described in this document contain potentially   sensitive information.  A security administrator may wish to limit   access to these MIBs.11.  References   [COEX]      The SNMPv3 Working Group, Frye, R.,Levi, D., Wijnen, B.,               "Coexistence between Version 1, Version 2, and Version 3               of the Internet-standard Network Management Framework",               Work in Progress.Levi, et al.                Standards Track                    [Page 67]

RFC 2573                   SNMP Applications                  April 1999   [RFC1157]   Case, J., Fedor, M., Schoffstall, M. and J. Davin,               "Simple Network Management Protocol", STD 15,RFC 1157,               May 1990.   [RFC1213]   McCloghrie, K. and M. Rose, Editors, "Management               Information Base for Network Management of TCP/IP-based               internets: MIB-II", STD 17,RFC 1213, March 1991.   [RFC2578]   McCloghrie, K., Perkins, D. and J. Schoenwaelder,               "Structure of Management Information Version 2 (SMIv2)",               STD 58,RFC 2578, April 1999.   [RFC2579]   McCloghrie, K., Perkins, D. and J.  Schoenwaelder,               "Textual Conventions for SMIv2", STD 58,RFC 2579, April               1999.   [RFC1905]   SNMPv2 Working Group, Case, J., McCloghrie, K., Rose, M.               and S.  Waldbusser, "Protocol Operations for Version 2 of               the Simple Network Management Protocol (SNMPv2)",RFC1905, January 1996.   [RFC1907]   SNMPv2 Working Group, Case, J., McCloghrie, K., Rose, M.               and S.  Waldbusser, "Management Information Base for               Version 2 of the Simple Network Management Protocol               (SNMPv2)",RFC1905, January 1996.   [RFC1908]   SNMPv2 Working Group, Case, J., McCloghrie, K., Rose, M.               and S.  Waldbusser, "Coexistence between Version 1 and               Version 2 of the Internet-standard Network Management               Framework",RFC1905, January 1996.   [RFC2119]   Bradner, S., "Key words for use in RFCs to Indicate               Requirement Levels",BCP 14,RFC2119, March 1997.   [RFC2571] Harrington, D., Presuhn, R. and B. Wijnen, "An Architecture               for Describing SNMP Management Frameworks",RFC 2571,               April 1999.   [RFC2572]   Case, J., Harrington, D., Presuhn, R. and B. Wijnen,               "Message Processing and Dispatching for the Simple               Network Management Protocol (SNMP)",RFC 2572, April               1999.   [RFC2575]  Wijnen, B., Presuhn, R. and K. McCloghrie, "View-based               Access Control Model for the Simple Network Management               Protocol (SNMP)",RFC 2575, April 1999.Levi, et al.                Standards Track                    [Page 68]

RFC 2573                   SNMP Applications                  April 1999   [RFC2573] Levi, D. B., Meyer, P. and B. Stewart, "SNMP Applications",RFC 2573, April 1999.12.  Editors' Addresses   David B. Levi   SNMP Research, Inc.   3001 Kimberlin Heights Road   Knoxville, TN 37920-9716   U.S.A.   Phone: +1 423 573 1434   EMail: levi@snmp.com   Paul Meyer   Secure Computing Corporation   2675 Long Lake Road   Roseville, MN 55113   U.S.A.   Phone: +1 651 628 1592   EMail: paul_meyer@securecomputing.com   Bob Stewart   Cisco Systems, Inc.   170 West Tasman Drive   San Jose, CA 95134-1706   U.S.A.   Phone: +1 603 654 2686   EMail: bstewart@cisco.comLevi, et al.                Standards Track                    [Page 69]

RFC 2573                   SNMP Applications                  April 1999APPENDIX A - Trap Configuration Example   This section describes an example configuration for a Notification   Generator application which implements the snmpNotifyBasicCompliance   level.  The example configuration specifies that the Notification   Generator should send notifications to 3 separate managers, using   authentication and no privacy for the first 2 managers, and using   both authentication and privacy for the third manager.   The configuration consists of three rows in the snmpTargetAddrTable,   and two rows in the snmpTargetTable.          snmpTargetAddrName         SnmpAdminString,          snmpTargetAddrTDomain      TDomain,          snmpTargetAddrTAddress     TAddress,          snmpTargetAddrTimeout      TimeInterval,          snmpTargetAddrRetryCount   Integer32,          snmpTargetAddrTagList      SnmpAdminString,          snmpTargetAddrParams       SnmpAdminString,          snmpTargetAddrStorageType  StorageType,          snmpTargetAddrRowStatus    RowStatus        * snmpTargetAddrName        = "addr1"          snmpTargetAddrTDomain     = snmpUDPDomain          snmpTargetAddrTAddress    = 128.1.2.3/162          snmpTargetAddrTagList     = "group1"          snmpTargetAddrParams      = "AuthNoPriv-joe"          snmpTargetAddrStorageType = readOnly(5)          snmpTargetAddrRowStatus   = active(1)        * snmpTargetAddrName        = "addr2"          snmpTargetAddrTDomain     = snmpUDPDomain          snmpTargetAddrTAddress    = 128.2.4.6/162          snmpTargetAddrTagList     = "group1"          snmpTargetAddrParams      = "AuthNoPriv-joe"          snmpTargetAddrStorageType = readOnly(5)          snmpTargetAddrRowStatus   = active(1)        * snmpTargetAddrName        = "addr3"          snmpTargetAddrTDomain     = snmpUDPDomain          snmpTargetAddrTAddress    = 128.1.2.3/162          snmpTargetAddrTagList     = "group2"          snmpTargetAddrParams      = "AuthPriv-bob"          snmpTargetAddrStorageType = readOnly(5)          snmpTargetAddrRowStatus   = active(1)        * snmpTargetParamsName                   = "AuthNoPriv-joe"          snmpTargetParamsMPModel                = 3mLevi, et al.                Standards Track                    [Page 70]

RFC 2573                   SNMP Applications                  April 1999          snmpTargetParamsSecurityModel          = 3 (USM)          snmpTargetParamsSecurityName           = "joe"          snmpTargetParamsSecurityLevel          = authNoPriv(2)          snmpTargetParamsStorageType            = readOnly(5)          snmpTargetParamsRowStatus              = active(1)        * snmpTargetParamsName                   = "AuthPriv-bob"          snmpTargetParamsMPModel                = 3          snmpTargetParamsSecurityModel          = 3 (USM)          snmpTargetParamsSecurityName           = "bob"          snmpTargetParamsSecurityLevel          = authPriv(3)          snmpTargetParamsStorageType            = readOnly(5)          snmpTargetParamsRowStatus              = active(1)        * snmpNotifyName         = "group1"          snmpNotifyTag          = "group1"          snmpNotifyType         = trap(1)          snmpNotifyStorageType  = readOnly(5)          snmpNotifyRowStatus    = active(1)        * snmpNotifyName         = "group2"          snmpNotifyTag          = "group2"          snmpNotifyType         = trap(1)          snmpNotifyStorageType  = readOnly(5)          snmpNotifyRowStatus    = active(1)   These entries define two groups of management targets.  The first   group contains two management targets:                                first target      second target                                ------------      -------------       messageProcessingModel   SNMPv3            SNMPv3                securityModel   3 (USM)           3 (USM)                 securityName   "joe"             "joe"                securityLevel   authNoPriv(2)     authNoPriv(2)              transportDomain   snmpUDPDomain     snmpUDPDomain             transportAddress   128.1.2.3/162     128.2.4.6/162   And the second group contains a single management target:       messageProcessingModel   SNMPv3                securityLevel   authPriv(3)                securityModel   3 (USM)                 securityName   "bob"              transportDomain   snmpUDPDomain             transportAddress   128.1.5.9/162Levi, et al.                Standards Track                    [Page 71]

RFC 2573                   SNMP Applications                  April 1999Appendix B.  Full Copyright Statement   Copyright (C) The Internet Society (1999).  All Rights Reserved.   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 distributed, in whole or in part, without restriction of any   kind, provided that the above copyright notice and this paragraph are   included on all such copies and derivative works.  However, this   document itself may not be modified in any way, such as by removing   the copyright notice or references to the Internet Society or other   Internet organizations, except as needed for the purpose of   developing Internet standards in which case the procedures for   copyrights defined in the Internet Standards process must be   followed, or as required to translate it into languages other than   English.   The limited permissions granted above are perpetual and will not be   revoked by the Internet Society or its successors or assigns.   This document and the information contained herein is provided on an   "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING   TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING   BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION   HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.Acknowledgement   Funding for the RFC Editor function is currently provided by   the Internet Society.Levi, et al.                Standards Track                    [Page 72]

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