SNMPv3 Applications

Status 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 © The Internet Society (1997). All Rights Reserved.

Abstract

This memo describes five types of SNMP applications which make use of an SNMP engine as described in [RFC2261]. 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 Contents

   1 Overview .....................................................    2
   1.1 Command Generator Applications .............................    3
   1.2 Command Responder Applications .............................    3
   1.3 Notification Originator Applications .......................    3
   1.4 Notification Receiver Applications .........................    3
   1.5 Proxy Forwarder Applications ...............................    3
   2 Management Targets ...........................................    5
   3 Elements Of Procedure ........................................    6
   3.1 Command Generator Applications .............................    6
   3.2 Command Responder Applications .............................    8
   3.3 Notification Originator Applications .......................   13
   3.4 Notification Receiver Applications .........................   16
   
   3.5 Proxy Forwarder Applications ...............................   18
   3.5.1 Request Forwarding .......................................   19
   3.5.1.1 Processing an Incoming Request .........................   19
   3.5.1.2 Processing an Incoming Response ........................   22
   3.5.1.3 Processing an Incoming Report Indication ...............   23
   3.5.2 Notification Forwarding ..................................   24
   4 The Structure of the MIB Modules .............................   27
   4.1 The Management Target MIB Module ...........................   27
   4.1.1 Tag Lists ................................................   28
   4.1.2 Definitions ..............................................   28
   4.2 The Notification MIB Module ................................   41
   4.2.1 Definitions ..............................................   42
   4.3 The Proxy MIB Module .......................................   53
   4.3.1 Definitions ..............................................   53
   5 Identification of Management Targets in Notification
        Originators ...............................................   59
   6 Notification Filtering .......................................   60
   7 Management Target Translation in Proxy  Forwarder
        Applications ..............................................   61
   7.1 Management Target Translation for Request Forwarding .......   61
   7.2 Management Target Translation for Notification Forwarding
        ...........................................................   62
   8 Intellectual Property ........................................   63
   9 Acknowledgments ..............................................   64
   10 Security Considerations .....................................   65
   11 References ..................................................   65
   12 Editors' Address ............................................   67
   A. Trap Configuration Example ..................................   68
   B. Full Copyright Statement ....................................   70

1. Overview

This document describes five types of SNMP applications:

       -  Applications which initiate SNMP Get, GetNext, GetBulk, and/or
          Set requests, called 'command generators.'

• Applications which respond to SNMP Get, GetNext, GetBulk, and/or Set requests, called 'command responders.'

• Applications which generate notifications, called 'notification originators.'

• Applications which receive notifications, called 'notification receivers.'

       -  Applications which forward SNMP Get, GetNext, GetBulk, and/or
          Set requests or notifications, called 'proxy forwarder.'

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.

1.1. Command Generator Applications

A command generator application initiates SNMP Get, GetNext, GetBulk, and/or Set requests, as well as processing the response to a request which it generated.

1.2. Command Responder Applications

A command responder application receives SNMP Get, GetNext, GetBulk, and/or Set 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 Trap and/or Inform 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.

1.4. Notification Receiver Applications

A notification receiver application listens for notification messages, and generates response messages when a message containing an Inform PDU is received.

1.5. 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 requests, notifications, and responses without regard for what managed objects are contained within requests or notifications. This definition is most closely related to the first definition above. Note, however, that in the SNMP architecture [RFC2261], 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:

• a proxy forwarder application forwards requests and/or notifications 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 Inform requests, the associated response is forwarded when it is received from the target to which the Inform request was forwarded, rather than generating a response immediately when an Inform request 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.

• 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 [RFC2261].

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.

• 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 PDU
         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 request 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 Get, GetNext, GetBulk, or Set 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.

• The pduType indicates a Get, GetNext, GetBulk, or Set 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.

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) If the SNMPv2 operation type is GetBulk, the non-repeaters and

max-repetitions values are extracted from the PDU and saved.

(4) The variable-bindings are extracted from the PDU and saved.

(5) The management operation represented by the SNMPv2 operation type

is performed with respect to the relevant MIB view within the context named by the contextName, according to the procedures set forth in [RFC1905]. The relevant MIB view is determined by the securityLevel, securityModel, contextName, securityName, and SNMPv2 operation 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 or write operation.

• The contextName is the value from the received message.

• 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 contructed 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 contructed 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 error

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.

3.3. Notification Originator Applications

A notification originator application generates SNMP notification messages. A notification message may, for example, contain an SNMPv2-Trap PDU or an Inform PDU. However, a particular implementation is not required to be capable of generating both types of messages.

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, whether the notification message should contain an SNMPv2-Trap PDU or Inform PDU, and if it is to contain an Inform 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 the preceding section. If the statusInformation returned by isAccessAllowed does not indicate accessAllowed, the notification is not sent to the management target.

(3) A PDU is constructed using a locally unique request-id value, an

operation type of SNMPv2-Trap or Inform, an error-status and error-index value of 0, and the variable-bindings supplied previously in step (2).

(4) If the notification contains an SNMPv2-Trap 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.

• 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,

(5) If the notification contains an Inform 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.

Responses to Inform PDU notifications will be received via the processResponsePDU abstract service interface.

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.

• 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 SNMPv2-Trap 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 SNMPv2-Trap 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 an Inform PDU is received, the notification receiver application follows the following procedure:

(1) The SNMPv2 operation type, request-id, error-status, error-index,

and variable-bindings are extracted from the PDU.

(2) A Response 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.

• 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 PDU type contained in a message, or according to whether a report indication is contained in the message. The four basic types of messages are:

• Those containing PDU types which were generated by a command generator application (for example, Get, GetNext, GetBulk, and Set PDU types). These deal with requesting or modifying information located within a particular context.

• Those containing PDU types which were generated by a notification originator application (for example, SNMPv2-Trap and Inform PDU types). These deal with notifications concerning information located within a particular context.

• Those containing a Response PDU type. Forwarding of Response PDUs always occurs as a result of receiving a response to a previously forwarded message.

• Those containing a report indication. Forwarding of report indications always occurs as a result of receiving a report indication for 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.

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 report indication matches, and to forward the report indication 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.

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,

(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 is SNMPv2 or SNMPv3 and the outgoing SNMP version is SNMPv1, in which case the proxy forwarder must apply the translation rules as documented in [RFC1908].

(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,

• 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 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 PDU.

(4) If the incoming SNMP version is SNMPv1 and the outgoing SNMP

version is SNMPv2 or SNMPv3, the proxy forwarder must apply the translation rules documented in [RFC1908].

(5) 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 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 Report Indication

A proxy forwarder follows the following procedure when an incoming report indication is received:

(1) The incoming report indication 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 report indication is halted. Otherwise:

(2) The cache information is extracted, and removed from the cache.

(3) If the original incoming management target information indicates

SNMPv1, processing of the report indication is halted.

(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 contain the contextEngineID, contextName, counter OID, and counter value received in the report indication.

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.

(2) If appropriate outgoing management target information cannot be

found and the notification was a Trap, processing of the notification is halted. If appropriate outgoing management target information cannot be found and the notification was an Inform, 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.

• 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 for any of the outgoing management targets, the incoming SNMP version is SNMPv1 and the outgoing SNMP version is SNMPv2 or SNMPv3, the proxy forwarder must apply the translation rules as documented in [RFC1908].

• If for any of the outgoing management targets, the incoming SNMP version is SNMPv2 or SNMPv3, and the outgoing SNMP version is SNMPv1, this outgoing management target is not used when generating the forwarded notifications.

(4) If the original received notification contains an SNMPv2-Trap PDU,

processing of the notification is now completed. Otherwise, the original received notification must contain an Inform PDU, and processing continues.

(5) If the forwarded notifications included any Inform PDUs, processing

continues when the procedures described in the section for Notification Originators determine that either:

• None of the generated notifications containing Inform 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 Inform PDUs is successfully acknowledged, in which case a response to the original received notification containing an Inform PDU is generated as described in the following steps.

(6) A Response PDU is constructed, using the values of request-id and

variable-bindings from the original received Inform 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.

• 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 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 in section 6.

• The use of the notification MIB for filtering notifications in notification originator applications is described in section 7.

• The use of the management target MIB and the proxy MIB in proxy forwarding applications is described in section 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.

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.

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.

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 charaters.

4.1.2. Definitions

   SNMP-TARGET-MIB DEFINITIONS ::= BEGIN

IMPORTS

       TEXTUAL-CONVENTION,
       MODULE-IDENTITY,
       OBJECT-TYPE,

snmpModules,
Integer32

           FROM SNMPv2-SMI
       
       TDomain,
       TAddress,
       TimeInterval,
       RowStatus,
       StorageType,
       TestAndIncr
           FROM SNMPv2-TC
       SnmpSecurityModel,
       SnmpMessageProcessingModel,
       SnmpSecurityLevel,
       SnmpAdminString
           FROM SNMP-FRAMEWORK-MIB

OBJECT-GROUP

           FROM SNMPv2-CONF;

snmpTargetMIB MODULE-IDENTITY

       LAST-UPDATED "9711210000Z"
       ORGANIZATION "IETF SNMPv3 Working Group"
       CONTACT-INFO
           "WG-email:   snmpv3@tis.com
            Subscribe:  majordomo@tis.com
                        In message body:  subscribe snmpv3
       
            Chair:      Russ Mundy
                        Trusted Information Systems
            Postal:     3060 Washington Rd
                        Glenwood MD 21738
                        USA
            Email:      mundy@tis.com
            Phone:      +1-301-854-6889
       
            Co-editor:  David B. Levi
                        SNMP Research, Inc.
            Postal:     3001 Kimberlin Heights Road
                        Knoxville, TN 37920-9716
            E-mail:     levi@snmp.com
            Phone:      +1 423 573 1434
       
            Co-editor:  Paul Meyer
                        Secure Computing Corporation
            Postal:     2675 Long Lake Road
                        Roseville, MN 55113
            E-mail:     paul_meyer@securecomputing.com
            Phone:      +1 612 628 1592
       
            Co-editor:  Bob Stewart
                        Cisco Systems, Inc.
            Postal:     170 West Tasman Drive
                        San Jose, CA 95134-1706
            E-mail:     bstewart@cisco.com
            Phone:      +1 603 654 6923"
       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        "9707140000Z"
       DESCRIPTION
           "The initial revision."
       ::= { snmpModules 7 }
   
   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.

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 in RFC 2044.

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 sub-identifiers for any object instance do 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:

• '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 in RFC 2044.

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).

• 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 multiple
            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,
       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 method
            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."
       ::= { 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      StorageType
       MAX-ACCESS  read-create
       STATUS      current
       DESCRIPTION
           "The storage type for this conceptual row."
       ::= { 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 snmpTargetAddrTDomain

and snmpTargetAddrTAddress have both been set.

            The following objects may not be modified while the
            value of this object is active(1):
                - snmpTargetAddrTDomain
                - snmpTargetAddrTAddress"
       ::= { 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      SnmpTargetParamsEntry
       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 (0..254 | 256..2147483647)
       MAX-ACCESS  read-create
       STATUS      current
       DESCRIPTION
           "The Security Model to be used when generating SNMP
             messages using this entry."
       ::= { 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."
       ::= { 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 made 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"
       ::= { 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 mesage 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 mesage was unknown."
       
       ::= { snmpTargetObjects 5 }
   
   --
   --
   -- Conformance information
   --
   --
   
   snmpTargetCompliances OBJECT IDENTIFIER ::=
                                           { snmpTargetConformance 1 }
   snmpTargetGroups      OBJECT IDENTIFIER ::=
                                           { snmpTargetConformance 2 }
   
   --
   --
   -- 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 }

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 }
   
   END

4.2. 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-MIB

SnmpTagValue,
snmpTargetParamsName

           FROM SNMP-TARGET-MIB

MODULE-COMPLIANCE,
OBJECT-GROUP

           FROM SNMPv2-CONF;

snmpNotificationMIB MODULE-IDENTITY

       LAST-UPDATED "9711210000Z"
       ORGANIZATION "IETF SNMPv3 Working Group"
       CONTACT-INFO
           "WG-email:   snmpv3@tis.com
            Subscribe:  majordomo@tis.com
                        In message body:  subscribe snmpv3
       
            Chair:      Russ Mundy
                        Trusted Information Systems
            Postal:     3060 Washington Rd
                        Glenwood MD 21738
                        USA
            Email:      mundy@tis.com
            Phone:      +1-301-854-6889
       
            Co-editor:  David B. Levi
                        SNMP Research, Inc.
            Postal:     3001 Kimberlin Heights Road
                        Knoxville, TN 37920-9716
            E-mail:     levi@snmp.com
            Phone:      +1 423 573 1434
            Co-editor:  Paul Meyer
                        Secure Computing Corporation
            Postal:     2675 Long Lake Road
                        Roseville, MN 55113
            E-mail:     paul_meyer@securecomputing.com
            Phone:      +1 612 628 1592
       
            Co-editor:  Bob Stewart
                        Cisco Systems, Inc.
            Postal:     170 West Tasman Drive
                        San Jose, CA 95134-1706
            E-mail:     bstewart@cisco.com
            Phone:      +1 603 654 6923"
       DESCRIPTION
           "This MIB module defines MIB objects which provide
            mechanisms to remotely configure the parameters
            used by an SNMP entity for the generation of
            notifications."
       REVISION    "9707140000Z"
       DESCRIPTION
           "The initial revision."
       ::= { snmpModules 8 }
   
   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,
       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."
       ::= { 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.

If the value of this object is trap(1), then any

messages generated for selected rows will contain

SNMPv2-Trap PDUs.

If the value of this object is inform(2), then any

messages generated for selected rows will contain

Inform PDUs.

            Note that if an SNMP entity only supports
            generation of traps (and not informs), 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."
       ::= { 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).

Until instances of all corresponding columns are appropriately configured, the value of the corresponding instance of the snmpNotifyRowStatus column is 'notReady'.

In particular, a newly created row cannot be made

active until the corresponding snmpNotifyTag has

been set."

       ::= { 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 created
            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."
       
       ::= { 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)."
       ::= { 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.  If the
            notification is matched by a filter, it is not sent to
            the management target with which the filter is
            associated."
       ::= { 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
       DESCRIPTION
           "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.

            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."
       DEFVAL { included }
       ::= { snmpNotifyFilterEntry 3 }

snmpNotifyFilterStorageType OBJECT-TYPE

       SYNTAX      StorageType
       MAX-ACCESS  read-create
       STATUS      current
       DESCRIPTION
           "The storage type of this conceptual row."
       ::= { 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 information
   --
   --
   
   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 Traps 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
           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 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-only
           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 Traps 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 Informs, or both SNMP Traps and SNMP
            Informs, 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 management
            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 }
   
   END

4.3. 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-MIB

SnmpTagValue,

           FROM SNMP-TARGET-MIB

MODULE-COMPLIANCE,
OBJECT-GROUP

           FROM SNMPv2-CONF;

snmpProxyMIB MODULE-IDENTITY

       LAST-UPDATED "9711210000Z"
       ORGANIZATION "IETF SNMPv3 Working Group"
       CONTACT-INFO
           "WG-email:   snmpv3@tis.com
            Subscribe:  majordomo@tis.com
                        In message body:  subscribe snmpv3
       
            Chair:      Russ Mundy
                        Trusted Information Systems
            Postal:     3060 Washington Rd
                        Glenwood MD 21738
                        USA
            Email:      mundy@tis.com
            Phone:      +1-301-854-6889
       
            Co-editor:  David B. Levi
                        SNMP Research, Inc.
            Postal:     3001 Kimberlin Heights Road
                        Knoxville, TN 37920-9716
            E-mail:     levi@snmp.com
            Phone:      +1 423 573 1434
       
            Co-editor:  Paul Meyer
                        Secure Computing Corporation
            Postal:     2675 Long Lake Road
                        Roseville, MN 55113
            E-mail:     paul_meyer@securecomputing.com
            Phone:      +1 612 628 1592
       
            Co-editor:  Bob Stewart
                        Cisco Systems, Inc.
            Postal:     170 West Tasman Drive
       
                        San Jose, CA 95134-1706
            E-mail:     bstewart@cisco.com
            Phone:      +1 603 654 6923"
       DESCRIPTION
           "This MIB module defines MIB objects which provide
            mechanisms to remotely configure the parameters
            used by a proxy forwarding application."
       REVISION    "9707140000Z"
       DESCRIPTION
           "The initial revision."
       ::= { snmpModules 9 }
   
   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
   }

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-TYPE

       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."
       ::= { snmpProxyEntry 8 }

snmpProxyRowStatus 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).

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 }

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 }
   
   END

5. 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 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 SNMPv2- Trap or Inform PDU is determined by the value of the snmpNotifyType object. If the value of this object is trap(1), the notification should contain an SNMPv2-Trap PDU. If the value of this object is inform(2), then the notification should contain an Inform PDU, and the timeout time and number of retries for the Inform are the value of snmpTargetAddrTimeout and snmpTargetAddrRetryCount. Note that the exception to these rules is when the snmpTargetParamsMPModel object indicates SNMPv1. In this case, the notification is sent as a Trap if the value of snmpNotifyTargetType is either trap(1) or inform(2).

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), and all of the object instances to be included in the variable-bindings of the notification, are not 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.

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. If none match, then the notification name or object instance is considered excluded, and the notification should not 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's 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 Get, GetNext, or GetBulk request. The snmpProxyType must be write(2) if the request is a Set request.

• 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.

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 a Trap. The snmpProxyType must be inform(4) if the request is an Inform.

• 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 in BCP-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.

9. 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:

Dave Battle (SNMP Research, Inc.)
Uri Blumenthal (IBM T.J. Watson Research Center)
Jeff Case (SNMP Research, Inc.)
John Curran (BBN)
T. Max Devlin (Hi-TECH Connections)
John Flick (Hewlett Packard)
David Harrington (Cabletron Systems Inc.)
N.C. Hien (IBM T.J. Watson Research Center)
Dave Levi (SNMP Research, Inc.)
Louis A Mamakos (UUNET Technologies Inc.)
Paul Meyer (Secure Computing Corporation)
Keith McCloghrie (Cisco Systems)
Russ Mundy (Trusted Information Systems, Inc.)
Bob Natale (ACE*COMM Corporation)
Mike O'Dell (UUNET Technologies Inc.)
Dave Perkins (DeskTalk)
Peter Polkinghorne (Brunel University)
Randy Presuhn (BMC Software, Inc.)
David Reid (SNMP Research, Inc.)
Shawn Routhier (Epilogue)
Juergen Schoenwaelder (TU Braunschweig)
Bob Stewart (Cisco Systems)
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:

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.

11. References

[RFC1157]

     Case, J., Fedor, M., Schoffstall, M. and J. Davin, "Simple Network
     Management Protocol", 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.

[RFC1902]

     Case, J., McCloghrie, K., Rose, M. and S. Waldbusser, "Structure of
     Management Information for Version 2 of the Simple Network
     Management Protocol (SNMPv2)", RFC 1902, January 1996.

[RFC1903]

     Case, J., McCloghrie, K., Rose, M. and S. Waldbusser, "Textual
     Conventions for Version 2 of the Simple Network Management Protocol
     (SNMPv2)", RFC 1903, January 1996.

[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)", RFC 1905, 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)", RFC 1907, 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", RFC 1908, January
     1996.

[RFC2261]

     Harrington, D., and B. Wijnen, "An Architecture for Describing SNMP
     Management Frameworks", RFC 2261, January 1998.

[RFC2262]

     Case, J., Harrington, D., and B. Wijnen, "Message Processing and
     Dispatching for the Simple Network Management Protocol (SNMP)", RFC
     2262, January 1998.

[RFC2265]

     Wijnen, B., Presuhn, R., and K. McCloghrie, "View-based Access
     Control Model for the Simple Network Management Protocol (SNMP)",
     RFC 2265, January 1998.

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: +1 612 628 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 6923
   EMail: bstewart@cisco.com

APPENDIX 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                = 3
          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   128.1.5.9:162

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