Simple Network Management Protocol (SNMP) 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.

Abstract

This document describes five types of Simple Network Management Protocol (SNMP) applications which make use of an SNMP engine as described in STD 62, RFC 3411. The types of application described are Command Generators, Command Responders, Notification Originators, Notification Receivers, and Proxy Forwarders.

This document also defines Management Information Base (MIB) modules for specifying targets of management operations, for notification filtering, and for proxy forwarding. This document obsoletes RFC 2573.

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 ...........................    4
   2       Management Targets .....................................    5
   3       Elements Of Procedure ..................................    6
   3.1     Command Generator Applications .........................    6
   3.2     Command Responder Applications .........................    9
   3.3     Notification Originator Applications ...................   14
   3.4     Notification Receiver Applications .....................   17
   3.5     Proxy Forwarder Applications ...........................   19
   3.5.1   Request Forwarding .....................................   21
   
   3.5.1.1 Processing an Incoming Request .........................   21
   3.5.1.2 Processing an Incoming Response ........................   24
   3.5.1.3 Processing an Incoming Internal-Class PDU ..............   25
   3.5.2   Notification Forwarding ................................   26
   4       The Structure of the MIB Modules .......................   29
   4.1     The Management Target MIB Module .......................   29
   4.1.1   Tag Lists .....................,........................   29
   4.1.2   Definitions ..................,.........................   30
   4.2     The Notification MIB Module ............................   44
   4.2.1   Definitions ............................................   44
   4.3     The Proxy MIB Module ...................................   56
   4.3.1   Definitions ............................................   57
   5       Identification of Management Targets in
           Notification Originators ...............................   63
   6       Notification Filtering .................................   64
   7       Management Target Translation in
           Proxy Forwarder Applications ...........................   65
   7.1     Management Target Translation for
           Request Forwarding .....................................   65
   7.2     Management Target Translation for
           Notification Forwarding ................................   66
   8       Intellectual Property ..................................   67
   9       Acknowledgments ........................................   67
   10      Security Considerations ................................   69
   11      References .............................................   69
   A.      Trap Configuration Example .............................   71
           Editors' Addresses .....................................   73
           Full Copyright Statement ...............................   74

1. Overview

This document describes five types of SNMP applications:

   - Applications which initiate SNMP Read-Class, and/or Write-Class
     requests, called 'command generators.'
   
   - Applications which respond to SNMP Read-Class, and/or Write-Class
     requests, called 'command responders.'

• Applications which generate SNMP Notification-Class PDUs, called 'notification originators.'

• Applications which receive SNMP Notification-Class PDUs, called 'notification receivers.'

• Applications which forward SNMP messages, called 'proxy forwarders.'

Note that there are no restrictions on which types of applications may be associated with a particular SNMP engine. For example, a single SNMP engine may, in fact, be associated with both command generator and command responder applications.

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119].

1.1. Command Generator Applications

A command generator application initiates SNMP Read-Class and/or Write-Class requests, and processes responses to requests which it generated.

1.2. Command Responder Applications

A command responder application receives SNMP Read-Class and/or Write-Class requests destined for the local system as indicated by the fact that the contextEngineID in the received request is equal to that of the local engine through which the request was received. The command responder application will perform the appropriate protocol operation, using access control, and will generate a response message to be sent to the request's originator.

1.3. Notification Originator Applications

A notification originator application conceptually monitors a system for particular events or conditions, and generates Notification-Class messages based on these events or conditions. A notification originator must have a mechanism for determining where to send messages, and what SNMP version and security parameters to use when sending messages. A mechanism and MIB module for this purpose is provided in this document. Note that Notification-Class PDUs generated by a notification originator may be either Confirmed-Class or Unconfirmed-Class PDU types.

1.4. Notification Receiver Applications

A notification receiver application listens for notification messages, and generates response messages when a message containing a Confirmed-Class PDU is received.

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 (3.5, 4.3, and 7) may be skipped for implementations that do not include a proxy forwarder application.

The term "proxy" has historically been used very loosely, with multiple different meanings. These different meanings include (among others):

(1) the forwarding of SNMP requests to other SNMP entities without

regard for what managed object types are being accessed; for example, in order to forward an SNMP request from one transport domain to another, or to translate SNMP requests of one version into SNMP requests of another version;

(2) the translation of SNMP requests into operations of some non-SNMP

       management protocol; and

(3) support for aggregated managed objects where the value of one

managed object instance depends upon the values of multiple other (remote) items of management information.

Each of these scenarios can be advantageous; for example, support for aggregation of management information can significantly reduce the bandwidth requirements of large-scale management activities.

However, using a single term to cover multiple different scenarios causes confusion.

To avoid such confusion, this document uses the term "proxy" with a much more tightly defined meaning. The term "proxy" is used in this document to refer to a proxy forwarder application which forwards either SNMP messages without regard for what managed objects are contained within those messages. This definition is most closely related to the first definition above. Note, however, that in the SNMP architecture [RFC3411], 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 SNMP messages to other SNMP engines according to the context, and irrespective of the specific managed object types being accessed, and forwards the response to such previously forwarded messages back to the SNMP engine from which the original message was received;

• in contrast, the command responder application that is part of what is traditionally thought of as an SNMP agent, and which processes SNMP requests according to the (names of the) individual managed object types and instances being accessed, is NOT a proxy forwarder application from the perspective of this document.

Thus, when a proxy forwarder application forwards a request or notification for a particular contextEngineID / contextName pair, not only is the information on how to forward the request specifically associated with that context, but the proxy forwarder application has no need of a detailed definition of a MIB view (since the proxy forwarder application forwards the request irrespective of the managed object types).

In contrast, a command responder application must have the detailed definition of the MIB view, and even if it needs to issue requests to other entities, via SNMP or otherwise, that need is dependent on the individual managed object instances being accessed (i.e., not only on the context).

Note that it is a design goal of a proxy forwarder application to act as an intermediary between the endpoints of a transaction. In particular, when forwarding Confirmed Notification-Class messages, the associated response is forwarded when it is received from the target to which the Notification-Class message was forwarded, rather than generating a response immediately when the Notification-Class message is received.

2. Management Targets

Some types of applications (notification generators and proxy forwarders in particular) require a mechanism for determining where and how to send generated messages. This document provides a mechanism and MIB module for this purpose. The set of information that describes where and how to send a message is called a 'Management Target', and consists of two kinds of information:

• Destination information, consisting of a transport domain and a transport address. This is also termed a transport endpoint.

• 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 [RFC3411].

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 to be generated.

• The securityLevel is the security level that the application wishes to use.

• The contextEngineID specifies the location of the management information it is requesting. Note that unless the request is being sent to a proxy, this value will usually be equal to the snmpEngineID value of the engine to which the request is being sent.

• The contextName specifies 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 Read-Class and/or Write-Class PDU.

Note that if another command responder application is already registered with an SNMP engine, any further attempts to register with the same contextEngineID and pduType will be denied. This implies that separate command responder applications could register separately for the various pdu types. However, in practice this is undesirable, and only a single command responder application should be registered with an SNMP engine at any given time.

A command responder application can disassociate with an SNMP engine using the following abstract service interface:

unregisterContextEngineID(

        IN   contextEngineID     -- give up responsibility for this one
        IN   pduType             -- the pduType(s) to be unregistered
             )

Where:

• The contextEngineID is equal to the snmpEngineID of the SNMP engine with which the command responder is cancelling the registration.

• The pduType indicates a Read-Class and/or Write-Class PDU.

Once the command responder has registered with the SNMP engine, it waits to receive SNMP messages. The abstract service interface used for receiving messages is:

   processPdu(                     -- process Request/Notification PDU
   
     IN   messageProcessingModel   -- typically, SNMP version
     IN   securityModel            -- Security Model in use
     IN   securityName             -- on behalf of this principal
     IN   securityLevel            -- Level of Security
     IN   contextEngineID          -- data from/at this SNMP entity
     IN   contextName              -- data from/in this context
     IN   pduVersion               -- the version of the PDU
     IN   PDU                      -- SNMP Protocol Data Unit
     IN   maxSizeResponseScopedPDU -- maximum size of the Response PDU
     IN   stateReference           -- reference to state information
          )                        -- needed when sending a response

Where:

• The messageProcessingModel indicates which Message Processing Model received and processed the message.

• The securityModel is the value from the received message.

• The securityName is the value from the received message.

• The securityLevel is the value from the received message.

• The contextEngineID is the value from the received message.

• The contextName is the value from the received message.

• The pduVersion indicates the version of the PDU in the received message.

• The PDU is the value from the received message.

• The maxSizeResponseScopedPDU is the maximum allowable size of a ScopedPDU containing a Response PDU (based on the maximum message size that the originator of the message can accept).

• The stateReference is a value which references cached information about each received request message. This value must be returned to the Dispatcher in order to generate a response.

The procedure when a message is received is as follows:

(1) The operation type is determined from the ASN.1 tag value

associated with the PDU parameter. The operation type should always be one of the types previously registered by the application.

(2) The request-id is extracted from the PDU and saved.

(3) Any PDU type specific parameters are extracted from the PDU and

saved (for example, if the PDU type is an SNMPv2 GetBulk PDU, the non-repeaters and max-repetitions values are extracted).

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

(5) The management operation represented by the PDU type is performed

with respect to the relevant MIB view within the context named by the contextName (for an SNMPv2 PDU type, the operation is performed according to the procedures set forth in [RFC1905]). The relevant MIB view is determined by the securityLevel, securityModel, contextName, securityName, and the class of the PDU type. To determine whether a particular object instance is within the relevant MIB view, the following abstract service interface is called:

          statusInformation =      -- success or errorIndication
            isAccessAllowed(
            IN   securityModel     -- Security Model in use
            IN   securityName      -- principal who wants to access
            IN   securityLevel     -- Level of Security
            IN   viewType          -- read, write, or notify view
            IN   contextName       -- context containing variableName
            IN   variableName      -- OID for the managed object
                 )

Where:

• The securityModel is the value from the received message.

• The securityName is the value from the received message.

• The securityLevel is the value from the received message.

• The viewType indicates whether the PDU type is a Read-Class or Write-Class operation.

• The contextName is the value from the received message.

• The variableName is the object instance of the variable for which access rights are to be checked.

Normally, the result of the management operation will be a new PDU value, and processing will continue in step (6) below. However, at any time during the processing of the management operation:

• If the isAccessAllowed ASI returns a noSuchView, noAccessEntry, or noGroupName error, processing of the management operation is halted, a PDU value is constructed using the values from the originally received PDU, but replacing the error-status with an authorizationError code, and error-index value of 0, and control is passed to step (6) below.

• If the isAccessAllowed ASI returns an otherError, processing of the management operation is halted, a different PDU value is constructed using the values from the originally received PDU, but replacing the error-status with a genError code and the error-index with the index of the failed variable binding, 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 for generation of a report message.

• 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 for generation of a report message.

(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.

Note that the text above describes situations where the snmpUnknownContexts counter is incremented, and where the snmpUnavailableContexts counter is incremented. The difference between these is that the snmpUnknownContexts counter is incremented when a request is received for a context which is unknown to the SNMP entity. The snmpUnavailableContexts counter is incremented when a request is received for a context which is known to the SNMP entity, but is currently unavailable. Determining when a context is unavailable is implementation specific, and some implementations may never encounter this situation, and so may never increment the snmpUnavailableContexts counter.

3.3. Notification Originator Applications

A notification originator application generates SNMP messages containing Notification-Class PDUs (for example, SNMPv2-Trap PDUs or Inform PDUs). There is no requirement as to what specific types of Notification-Class PDUs a particular implementation must be capable of generating.

Notification originator applications require a mechanism for identifying the management targets to which notifications should be sent. The particular mechanism used is implementation dependent. However, if an implementation makes the configuration of management targets SNMP manageable, it MUST use the SNMP-TARGET-MIB module described in this document.

When a notification originator wishes to generate a notification, it must first determine in which context the information to be conveyed in the notification exists, i.e., it must determine the contextEngineID and contextName. It must then determine the set of management targets to which the notification should be sent. The application must also determine, for each management target, what specific PDU type the notification message should contain, and if it is to contain a Confirmed-Class PDU, the number of retries and retransmission algorithm.

The mechanism by which a notification originator determines this information is implementation dependent. Once the application has determined this information, the following procedure is performed for each management target:

(1) Any appropriate filtering mechanisms are applied to determine

whether the notification should be sent to the management target. If such filtering mechanisms determine that the notification should not be sent, processing continues with the next management target. Otherwise,

(2) The appropriate set of variable-bindings is retrieved from local

MIB instrumentation within the relevant MIB view. The relevant MIB view is determined by the securityLevel, securityModel, contextName, and securityName of the management target. To determine whether a particular object instance is within the relevant MIB view, the isAccessAllowed abstract service interface is used, in the same manner as described in the preceding section, except that the viewType indicates a Notification-Class operation. If the statusInformation returned by isAccessAllowed does not indicate accessAllowed, the notification is not sent to the management target.

(3) The NOTIFICATION-TYPE OBJECT IDENTIFIER of the notification (this

is the value of the element of the variable bindings whose name is snmpTrapOID.0, i.e., the second variable binding) is checked using the isAccessAllowed abstract service interface, using the same parameters used in the preceding step. If the statusInformation returned by isAccessAllowed does not indicate accessAllowed, the notification is not sent to the management target.

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

PDU type as determined by the implementation, an error-status and error-index value of 0, and the variable-bindings supplied previously in step (2).

(5) If the notification contains an Unconfirmed-Class PDU, the

Dispatcher is called using the following abstract service interface:

       statusInformation =              -- sendPduHandle if success
       
                                        -- errorIndication if failure
         sendPdu(
         IN   transportDomain           -- transport domain to be used
         IN   transportAddress          -- destination network address
         IN   messageProcessingModel    -- typically, SNMP version
         IN   securityModel             -- Security Model to use
         IN   securityName              -- on behalf of this principal
         IN   securityLevel             -- Level of Security requested
         IN   contextEngineID           -- data from/at this entity
         IN   contextName               -- data from/in this context
         IN   pduVersion                -- the version of the PDU
         IN   PDU                       -- SNMP Protocol Data Unit
         IN   expectResponse            -- TRUE or FALSE
              )

Where:

• The transportDomain is that of the management target.

• The transportAddress is that of the management target.

• The messageProcessingModel is that of the management target.

• The securityModel is that of the management target.

• 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 (4) above.

• The expectResponse argument indicates that no response is expected.

Otherwise,

(6) If the notification contains a Confirmed-Class PDU, then:

a) The Dispatcher is called using the sendPdu abstract service

interface as described in step (5) above, except that the expectResponse argument indicates that a response is expected.

b) The application caches information about the management

target.

c) If a response is received within an appropriate time interval

from the transport endpoint of the management target, the notification is considered acknowledged and the cached information is deleted. Otherwise,

d) If a response is not received within an appropriate time

period, or if a report indication is received, information about the management target is retrieved from the cache, and steps a) through d) are repeated. The number of times these steps are repeated is equal to the previously determined retry count. If this retry count is exceeded, the acknowledgement of the notification is considered to have failed, and processing of the notification for this management target is halted. Note that some report indications might be considered a failure. Such report indications should be interpreted to mean that the acknowledgement of the notification has failed, and that steps a) through d) need not be repeated.

Responses to Confirmed-Class PDU notifications will be received via the processResponsePdu abstract service interface.

To summarize, the steps that a notification originator follows when determining where to send a notification are:

• Determine the targets to which the notification should be sent.

• Apply any required filtering to the list of targets.

• Determine which targets are authorized to receive the notification.

3.4. Notification Receiver Applications

Notification receiver applications receive SNMP Notification messages from the Dispatcher. Before any messages can be received, the notification receiver must register with the Dispatcher using the registerContextEngineID abstract service interface. The parameters used are:

• The contextEngineID is an undefined 'wildcard' value. Notifications are delivered to a registered notification receiver regardless of the contextEngineID contained in the notification message.

• The pduType indicates the type of notifications that the application wishes to receive (for example, SNMPv2-Trap PDUs or Inform PDUs).

Once the notification receiver has registered with the Dispatcher, messages are received using the processPdu abstract service interface. Parameters are:

• The messageProcessingModel indicates which Message Processing Model received and processed the message.

• The securityModel is the value from the received message.

• The securityName is the value from the received message.

• The securityLevel is the value from the received message.

• The contextEngineID is the value from the received message.

• The contextName is the value from the received message.

• The pduVersion indicates the version of the PDU in the received message.

• The PDU is the value from the received message.

• The maxSizeResponseScopedPDU is the maximum allowable size of a ScopedPDU containing a Response PDU (based on the maximum message size that the originator of the message can accept).

• If the message contains an Unconfirmed-Class PDU, the stateReference is undefined and unused. Otherwise, the stateReference is a value which references cached information about the notification. This value must be returned to the Dispatcher in order to generate a response.

When an Unconfirmed-Class PDU is delivered to a notification receiver application, it first extracts the SNMP operation type, request-id, error-status, error-index, and variable-bindings from the PDU. After this, processing depends on the particular implementation.

When a Confirmed-Class PDU is received, the notification receiver application follows the following procedure:

   (1) The PDU type, request-id, error-status, error-index, and
   
       variable-bindings are extracted from the PDU.

(2) A Response-Class PDU is constructed using the extracted

request-id and variable-bindings, and with error-status and error-index both set to 0.

(3) The Dispatcher is called to generate a response message using the

returnResponsePdu abstract service interface. Parameters are:

• The messageProcessingModel is the value from the processPdu call.

• The securityModel is the value from the processPdu call.

• The securityName is the value from the processPdu call.

• The securityLevel is the value from the processPdu call.

• The contextEngineID is the value from the processPdu call.

• The contextName is the value from the processPdu call.

• The pduVersion indicates the version of the PDU to be returned.

• 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.

(4) After this, processing depends on the particular implementation.

3.5. Proxy Forwarder Applications

A proxy forwarder application deals with forwarding SNMP messages. There are four basic types of messages which a proxy forwarder application may need to forward. These are grouped according to the class of PDU type contained in a message. The four basic types of messages are:

• Those containing Read-Class or Write-Class PDU types (for example, Get, GetNext, GetBulk, and Set PDU types). These deal with requesting or modifying information located within a particular context.

• Those containing Notification-Class PDU types (for example, SNMPv2-Trap and Inform PDU types). These deal with notifications concerning information located within a particular context.

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

• Those containing Internal-Class PDU types (for example, a Report PDU). Forwarding of Internal-Class PDU types always occurs as a result of receiving an Internal-Class PDU in response to a previously forwarded message.

For the first type, the proxy forwarder's role is to deliver a request for management information to an SNMP engine which is "closer" or "downstream in the path" to the SNMP engine which has access to that information, and to deliver the response containing the information back to the SNMP engine from which the request was received. The context information in a request is used to determine which SNMP engine has access to the requested information, and this is used to determine where and how to forward the request.

For the second type, the proxy forwarder's role is to determine which SNMP engines should receive notifications about management information from a particular location. The context information in a notification message determines the location to which the information contained in the notification applies. This is used to determine which SNMP engines should receive notification about this information.

For the third type, the proxy forwarder's role is to determine which previously forwarded request or notification (if any) the response matches, and to forward the response back to the initiator of the request or notification.

For the fourth type, the proxy forwarder's role is to determine which previously forwarded request or notification (if any) the Internal- Class PDU matches, and to forward the Internal-Class PDU back to the initiator of the request or notification.

When forwarding messages, a proxy forwarder application must perform a translation of incoming management target information into outgoing management target information. How this translation is performed is implementation specific. In many cases, this will be driven by a preconfigured translation table. If a proxy forwarder application makes the contents of this table SNMP manageable, it MUST use the SNMP-PROXY-MIB module defined in this document.

3.5.1. Request Forwarding

There are two phases for request forwarding. First, the incoming request needs to be passed through the proxy application. Then, the resulting response needs to be passed back. These phases are described in the following two sections.

3.5.1.1. Processing an Incoming Request

A proxy forwarder application that wishes to forward request messages must first register with the Dispatcher using the registerContextEngineID abstract service interface. The proxy forwarder must register each contextEngineID for which it wishes to forward messages, as well as for each pduType. Note that as the configuration of a proxy forwarder is changed, the particular contextEngineID values for which it is forwarding may change. The proxy forwarder should call the registerContextEngineID and unregisterContextEngineID abstract service interfaces as needed to reflect its current configuration.

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 and the outgoing SNMP version support different PDU versions, in which case the proxy forwarder may need to perform a translation on the PDU. (A method for performing such a translation is described in [RFC2576].)

(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 from the processPdu call.

• The contextName is the value from the processPdu call.

• 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-Class PDU is constructed, using the request-id

value from the original forwarded request (as extracted from the cache). All other values are identical to those in the received Response-Class PDU, unless the incoming SNMP version and the outgoing SNMP version support different PDU versions, in which case the proxy forwarder may need to perform a translation on the PDU. (A method for performing such a translation is described in [RFC2576].)

(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 the (possibly translated) Response PDU.

• The maxSizeResponseScopedPDU is a local value indicating the maximum size of a ScopedPDU that the application can accept.

• The stateReference is the value extracted from the cache.

• The statusInformation indicates that no error occurred and that a Response PDU message should be generated.

3.5.1.3. Processing an Incoming Internal-Class PDU

A proxy forwarder follows the following procedure when an incoming Internal-Class PDU is received:

(1) The incoming Internal-Class PDU is received using the

processResponsePdu interface. The proxy forwarder uses the received parameters to locate an entry in its cache of pending forwarded requests. This is done by matching the received parameters with the cached values of sendPduHandle. If an appropriate cache entry cannot be found, processing of the Internal-Class PDU is halted. Otherwise:

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

(3) If the original incoming management target information indicates

an SNMP version which does not support Report PDUs, processing of the Internal-Class PDU is halted.

(4) The proxy forwarder calls the Dispatcher using the

returnResponsePdu abstract service interface. Parameters are:

• The messageProcessingModel indicates the Message Processing Model by which the original incoming message was processed.

• The securityModel is that of the original incoming management target extracted from the cache.

• The securityName is that of the original incoming management target extracted from the cache.

• The securityLevel is that of the original incoming management target extracted from the cache.

• The contextEngineID is the value extracted from the cache.

• The contextName is the value extracted from the cache.

• The pduVersion indicates the version of the PDU to be returned.

• The PDU is unused.

• The maxSizeResponseScopedPDU is a local value indicating the maximum size of a ScopedPDU that the application can accept.

• The stateReference is the value extracted from the cache.

• The statusInformation contains values specific to the Internal-Class PDU type (for example, for a Report PDU, the statusInformation contains the contextEngineID, contextName, counter OID, and counter value received in the incoming Report PDU).

3.5.2. Notification Forwarding

A proxy forwarder receives notifications in the same manner as a notification receiver application, using the processPdu abstract service interface. The following procedure is used when a notification is received:

(1) The incoming management target information received from the

processPdu interface is translated into outgoing management target information. Note that this translation may vary for different values of contextEngineID and/or contextName. The translation may result in multiple management targets.

(2) If appropriate outgoing management target information cannot be

found and the notification was an Unconfirmed-Class PDU, processing of the notification is halted. If appropriate outgoing management target information cannot be found and the notification was a Confirmed-Class PDU, the proxy forwarder increments the snmpProxyDrops object, and calls the Dispatcher using the returnResponsePdu abstract service interface. The parameters are:

• The messageProcessingModel is the 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 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 value from the processPdu call.

• 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, nor to the value of the variable-binding containing snmpTrapOID.0.

• If the original notification contains a Confirmed-Class PDU, then any outgoing management targets for which the outgoing SNMP version does not support any PDU types that are both Notification-Class and Confirmed-Class PDUs will not be used when generating the forwarded notifications.

• If, for any of the outgoing management targets, the incoming SNMP version and the outgoing SNMP version support different PDU versions, the proxy forwarder may need to perform a translation on the PDU. (A method for performing such a translation is described in [RFC2576].)

(4) If the original received notification contains an

Unconfirmed-Class PDU, processing of the notification is now completed. Otherwise, the original received notification must contain Confirmed-Class PDU, and processing continues.

(5) If the forwarded notifications included any Confirmed-Class PDUs,

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

• None of the generated notifications containing Confirmed-Class PDUs have been successfully acknowledged within the longest of the time intervals, in which case processing of the original notification is halted, or,

• At least one of the generated notifications containing Confirmed-Class PDUs is successfully acknowledged, in which case a response to the original received notification containing an Confirmed-Class PDU is generated as described in the following steps.

(6) A Response-Class PDU is constructed, using the values of

request-id and variable-bindings from the original received Notification-Class PDU, and error-status and error-index values of 0.

(7) The Dispatcher is called using the returnResponsePdu abstract

service interface. Parameters are:

• The messageProcessingModel is the 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 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 value from the processPdu call.

• The statusInformation indicates that no error occurred and that a Response-Class PDU message should be generated.

4. The Structure of the MIB Modules

There are three separate MIB modules described in this document, the management target MIB, the notification MIB, and the proxy MIB. The following sections describe the structure of these three MIB modules.

The use of these MIBs by particular types of applications is described later in this document:

• The use of the management target MIB and the notification MIB in notification originator applications is described in section 5.

• The use of the notification MIB for filtering notifications in notification originator applications is described in section 6.

• The use of the management target MIB and the proxy MIB in proxy forwarding applications is described in section 7.

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.

The Management Target MIB is intended to provide a general-purpose mechanism for specifying transport address, and for specifying parameters of SNMP messages generated by an SNMP entity. It is used within this document for generation of notifications and for proxy forwarding. However, it may be used for other purposes. If another document makes use of this MIB, that document is responsible for specifying how it is used. For example, [RFC2576] uses this MIB for source address validation of SNMPv1 messages.

4.1.1. Tag Lists

The snmpTargetAddrTagList object is used for grouping entries in the snmpTargetAddrTable. The value of this object contains a list of tag values which are used to select target addresses to be used for a particular operation.

A tag value, which may also be used in MIB objects other than snmpTargetAddrTagList, is an arbitrary string of octets, but may not contain a delimiter character. Delimiter characters are defined to be one of the following characters:

• An ASCII space character (0x20).

• An ASCII TAB character (0x09).

• An ASCII carriage return (CR) character (0x0D).

• An ASCII line feed (LF) character (0x0A).

In addition, a tag value within a tag list may not have a zero length. Generally, a particular MIB object may contain either

• a zero-length octet string representing an empty list, or

• a single tag value, in which case the value of the MIB object may not contain a delimiter character, or

• 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 characters.

4.1.2. Definitions

   SNMP-TARGET-MIB DEFINITIONS ::= BEGIN

IMPORTS

       MODULE-IDENTITY,
       OBJECT-TYPE,
       snmpModules,
       Counter32,
       Integer32
           FROM SNMPv2-SMI
       
       TEXTUAL-CONVENTION,
       TDomain,
       TAddress,
       TimeInterval,
       RowStatus,
       StorageType,

TestAndIncr

           FROM SNMPv2-TC

SnmpSecurityModel,
SnmpMessageProcessingModel,
SnmpSecurityLevel,
SnmpAdminString

           FROM SNMP-FRAMEWORK-MIB

MODULE-COMPLIANCE,
OBJECT-GROUP

           FROM SNMPv2-CONF;

snmpTargetMIB MODULE-IDENTITY

       LAST-UPDATED "200210140000Z"
       ORGANIZATION "IETF SNMPv3 Working Group"
       CONTACT-INFO
           "WG-email:   snmpv3@lists.tislabs.com
            Subscribe:  majordomo@lists.tislabs.com
                        In message body:  subscribe snmpv3
       
            Co-Chair:   Russ Mundy
                        Network Associates Laboratories
            Postal:     15204 Omega Drive, Suite 300
                        Rockville, MD 20850-4601
                        USA
            EMail:      mundy@tislabs.com
            Phone:      +1 301-947-7107
       
            Co-Chair:   David Harrington
                        Enterasys Networks
            Postal:     35 Industrial Way
                        P. O. Box 5004
                        Rochester, New Hampshire 03866-5005
                        USA
            EMail:      dbh@enterasys.com
            Phone:      +1 603-337-2614
       
            Co-editor:  David B. Levi
                        Nortel Networks
            Postal:     3505 Kesterwood Drive
                        Knoxville, Tennessee 37918
            EMail:      dlevi@nortelnetworks.com
            Phone:      +1 865 686 0432
       
            Co-editor:  Paul Meyer
                        Secure Computing Corporation
            Postal:     2675 Long Lake Road

Roseville, Minnesota 55113

EMail: paul_meyer@securecomputing.com

Phone: +1 651 628 1592

            Co-editor:  Bob Stewart
                        Retired"
       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.
       
            Copyright © The Internet Society (2002). This
            version of this MIB module is part of RFC 3413;
            see the RFC itself for full legal notices.
           "
       REVISION    "200210140000Z"             -- 14 October 2002
       DESCRIPTION "Fixed DISPLAY-HINTS for UTF-8 strings, fixed hex
                    value of LF characters, clarified meaning of zero
                    length tag values, improved tag list examples.
                    Published as RFC 3413."
       REVISION    "199808040000Z"             -- 4 August 1998
       DESCRIPTION "Clarifications, published as
                    RFC 2573."
       REVISION    "199707140000Z"             -- 14 July 1997
       DESCRIPTION "The initial revision, published as RFC2273."
       ::= { snmpModules 12 }
   
   snmpTargetObjects       OBJECT IDENTIFIER ::= { snmpTargetMIB 1 }
   snmpTargetConformance   OBJECT IDENTIFIER ::= { snmpTargetMIB 3 }

SnmpTagValue ::= TEXTUAL-CONVENTION

       DISPLAY-HINT "255t"
       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 2279.

Since additional code points are added by amendments to the 10646 standard from time to time, implementations must be prepared to encounter any code point from 0x00000000 to 0x7fffffff.

The use of control codes should be avoided, and certain

control codes are not allowed as described below.

For code points not directly supported by user interface hardware or software, an alternative means of entry and display, such as hexadecimal, may be provided.

For information encoded in 7-bit US-ASCII, the UTF-8 representation is identical to the US-ASCII encoding.

Note that when this TC is used for an object that is used or envisioned to be used as an index, then a SIZE restriction must be specified so that the number of sub-identifiers for any object instance does not exceed the limit of 128, as defined by [RFC1905].

An object of this type contains a single tag value

which is used to select a set of entries in a table.

A tag value is an arbitrary string of octets, but

may not contain a delimiter character. Delimiter

characters are defined to be one of the following:

- An ASCII space character (0x20).

• An ASCII TAB character (0x09).

• An ASCII carriage return (CR) character (0x0D).

- An ASCII line feed (LF) character (0x0A).

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.

Note that a tag value of 0 length means that no tag is defined. In other words, a tag value of 0 length would never match anything in a tag list, and would never select any table entries.

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 "255t"
       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 2279.

Since additional code points are added by amendments to the 10646 standard from time to time, implementations must be prepared to encounter any code point from 0x00000000 to 0x7fffffff.

The use of control codes should be avoided, except as described below.

For code points not directly supported by user interface hardware or software, an alternative means of entry and display, such as hexadecimal, may be provided.

For information encoded in 7-bit US-ASCII, the UTF-8 representation is identical to the US-ASCII encoding.

An object of this type contains a list of tag values which are used to select a set of entries in a table.

A tag value is an arbitrary string of octets, but

may not contain a delimiter character. Delimiter

characters are defined to be one of the following:

- An ASCII space character (0x20).

• An ASCII TAB character (0x09).

• An ASCII carriage return (CR) character (0x0D).

- An ASCII line feed (LF) character (0x0A).

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 list

                - 'acme'                    -- list of one tag
                
                - 'host router bridge'      -- list of several tags

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."
       DEFVAL { "" }
       ::= { snmpTargetAddrEntry 6 }

snmpTargetAddrParams OBJECT-TYPE

       SYNTAX      SnmpAdminString (SIZE(1..32))
       MAX-ACCESS  read-create
       STATUS      current
       DESCRIPTION
           "The value of this object identifies an entry in the
            snmpTargetParamsTable.  The identified entry
            contains SNMP parameters to be used when generating
            messages to be sent to this transport address."
       ::= { snmpTargetAddrEntry 7 }

snmpTargetAddrStorageType OBJECT-TYPE

       SYNTAX      StorageType
       MAX-ACCESS  read-create
       STATUS      current
       DESCRIPTION
           "The storage type for this conceptual row.
            Conceptual rows having the value 'permanent' need not
            allow write-access to any columnar objects in the row."
       
       DEFVAL { nonVolatile }
       ::= { snmpTargetAddrEntry 8 }

snmpTargetAddrRowStatus OBJECT-TYPE

       SYNTAX      RowStatus
       MAX-ACCESS  read-create
       STATUS      current
       DESCRIPTION
           "The status of this conceptual row.

To create a row in this table, a manager must

set this object to either createAndGo(4) or

createAndWait(5).

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

In particular, a newly created row cannot be made active until the corresponding instances of snmpTargetAddrTDomain, snmpTargetAddrTAddress, and snmpTargetAddrParams have all been set.

            The following objects may not be modified while the
            value of this object is active(1):
                - snmpTargetAddrTDomain
                - snmpTargetAddrTAddress
            An attempt to set these objects while the value of
            snmpTargetAddrRowStatus is active(1) will result in
            an inconsistentValue error."
       ::= { snmpTargetAddrEntry 9 }

snmpTargetParamsTable OBJECT-TYPE

       SYNTAX      SEQUENCE OF SnmpTargetParamsEntry
       MAX-ACCESS  not-accessible
       STATUS      current
       DESCRIPTION
           "A table of SNMP target information to be used
            in the generation of SNMP messages."
       ::= { snmpTargetObjects 3 }

snmpTargetParamsEntry OBJECT-TYPE

       SYNTAX      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 (1..2147483647)
       MAX-ACCESS  read-create
       STATUS      current
       DESCRIPTION
           "The Security Model to be used when generating SNMP
             messages using this entry.  An implementation may
             choose to return an inconsistentValue error if an
             attempt is made to set this variable to a value
             for a security model which the implementation does
             not support."
       ::= { snmpTargetParamsEntry 3 }

snmpTargetParamsSecurityName OBJECT-TYPE

       SYNTAX      SnmpAdminString
       MAX-ACCESS  read-create
       STATUS      current
       DESCRIPTION
           "The securityName which identifies the Principal on
            whose behalf SNMP messages will be generated using
            this entry."
       ::= { snmpTargetParamsEntry 4 }

snmpTargetParamsSecurityLevel OBJECT-TYPE

       SYNTAX      SnmpSecurityLevel
       MAX-ACCESS  read-create
       STATUS      current
       DESCRIPTION
           "The Level of Security to be used when generating
            SNMP messages using this entry."
       ::= { snmpTargetParamsEntry 5 }

snmpTargetParamsStorageType OBJECT-TYPE

       SYNTAX      StorageType
       MAX-ACCESS  read-create
       STATUS      current
       DESCRIPTION
           "The storage type for this conceptual row.
            Conceptual rows having the value 'permanent' need not
            allow write-access to any columnar objects in the row."
       DEFVAL { nonVolatile }
       ::= { snmpTargetParamsEntry 6 }

snmpTargetParamsRowStatus OBJECT-TYPE

       SYNTAX      RowStatus
       MAX-ACCESS  read-create
       STATUS      current
       DESCRIPTION
           "The status of this conceptual row.

To create a row in this table, a manager must

set this object to either createAndGo(4) or

createAndWait(5).

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

In particular, a newly created row cannot be 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
            An attempt to set these objects while the value of
            snmpTargetParamsRowStatus is active(1) will result in
            an inconsistentValue error."
       ::= { snmpTargetParamsEntry 7 }

snmpUnavailableContexts OBJECT-TYPE

       SYNTAX       Counter32
       MAX-ACCESS   read-only
       STATUS       current
       DESCRIPTION
           "The total number of packets received by the SNMP
            engine which were dropped because the context
            contained in the message was unavailable."
       ::= { snmpTargetObjects 4 }

snmpUnknownContexts OBJECT-TYPE

       SYNTAX       Counter32
       MAX-ACCESS   read-only
       STATUS       current
       DESCRIPTION
           "The total number of packets received by the SNMP
            engine which were dropped because the context
            contained in the message was unknown."
       ::= { snmpTargetObjects 5 }
   
   --
   --
   -- Conformance information
   --
   --
   
   snmpTargetCompliances OBJECT IDENTIFIER ::=
                                           { snmpTargetConformance 1 }
   snmpTargetGroups      OBJECT IDENTIFIER ::=
                                           { snmpTargetConformance 2 }
   
   --
   --
   -- 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, the snmpNotifyFilterProfileTable, sparsely augments the snmpTargetParamsTable with an object which is used to associate a set of filters with a particular management target.

The third table, the snmpNotifyFilterTable, 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 "200210140000Z"
       ORGANIZATION "IETF SNMPv3 Working Group"
       CONTACT-INFO
           "WG-email:   snmpv3@lists.tislabs.com
            Subscribe:  majordomo@lists.tislabs.com
                        In message body:  subscribe snmpv3
       
            Co-Chair:   Russ Mundy
                        Network Associates Laboratories
            Postal:     15204 Omega Drive, Suite 300
                        Rockville, MD 20850-4601
                        USA
            EMail:      mundy@tislabs.com
            Phone:      +1 301-947-7107
       
            Co-Chair:   David Harrington
                        Enterasys Networks
            Postal:     35 Industrial Way
                        P. O. Box 5004
                        Rochester, New Hampshire 03866-5005
                        USA
            EMail:      dbh@enterasys.com
            Phone:      +1 603-337-2614
       
            Co-editor:  David B. Levi
                        Nortel Networks
            Postal:     3505 Kesterwood Drive
                        Knoxville, Tennessee 37918
            EMail:      dlevi@nortelnetworks.com
            Phone:      +1 865 686 0432
       
            Co-editor:  Paul Meyer
                        Secure Computing Corporation
            Postal:     2675 Long Lake Road
                        Roseville, Minnesota 55113
            EMail:      paul_meyer@securecomputing.com
            Phone:      +1 651 628 1592
       
            Co-editor:  Bob Stewart
                        Retired"

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.

            Copyright © The Internet Society (2002). This
            version of this MIB module is part of RFC 3413;
            see the RFC itself for full legal notices.
           "
       REVISION    "200210140000Z"             -- 14 October 2002
       DESCRIPTION "Clarifications, published as
                    RFC 3413."
       REVISION    "199808040000Z"             -- 4 August 1998
       DESCRIPTION "Clarifications, published as
                    RFC 2573."
       REVISION    "199707140000Z"             -- 14 July 1997
       DESCRIPTION "The initial revision, published as RFC2273."
       ::= { snmpModules 13 }
   
   snmpNotifyObjects       OBJECT IDENTIFIER ::=
                                             { snmpNotificationMIB 1 }
   snmpNotifyConformance   OBJECT IDENTIFIER ::=
                                             { snmpNotificationMIB 3 }
   
   --
   --
   -- The snmpNotifyObjects group
   --
   --

snmpNotifyTable OBJECT-TYPE

       SYNTAX      SEQUENCE OF SnmpNotifyEntry
       MAX-ACCESS  not-accessible
       STATUS      current
       DESCRIPTION
           "This table is used to select management targets which should
            receive notifications, as well as the type of notification
            which should be sent to each selected management target."
       ::= { snmpNotifyObjects 1 }

snmpNotifyEntry OBJECT-TYPE

       SYNTAX      SnmpNotifyEntry
       MAX-ACCESS  not-accessible
       STATUS      current
       DESCRIPTION
           "An entry in this table selects a set of management targets
            which should receive notifications, as well as the type of

notification which should be sent to each selected management target.

            Entries in the snmpNotifyTable are created and
            deleted using the snmpNotifyRowStatus object."
       INDEX { IMPLIED snmpNotifyName }
       ::= { snmpNotifyTable 1 }
   
   SnmpNotifyEntry ::= SEQUENCE {
       snmpNotifyName         SnmpAdminString,
       snmpNotifyTag          SnmpTagValue,
       snmpNotifyType         INTEGER,
       snmpNotifyStorageType  StorageType,
       snmpNotifyRowStatus    RowStatus
   }

snmpNotifyName OBJECT-TYPE

       SYNTAX      SnmpAdminString (SIZE(1..32))
       MAX-ACCESS  not-accessible
       STATUS      current
       DESCRIPTION
           "The locally arbitrary, but unique identifier associated
            with this snmpNotifyEntry."
       ::= { snmpNotifyEntry 1 }

snmpNotifyTag OBJECT-TYPE

       SYNTAX      SnmpTagValue
       MAX-ACCESS  read-create
       STATUS      current
       DESCRIPTION
           "This object contains a single tag value which is used
            to select entries in the snmpTargetAddrTable.  Any entry
            in the snmpTargetAddrTable which contains a tag value
            which is equal to the value of an instance of this
            object is selected.  If this object contains a value
            of zero length, no entries are selected."
       DEFVAL { "" }
       ::= { snmpNotifyEntry 2 }

snmpNotifyType OBJECT-TYPE

       SYNTAX      INTEGER {
                       trap(1),
                       inform(2)
                   }
       MAX-ACCESS  read-create
       STATUS      current
       DESCRIPTION
           "This object determines the type of notification to

be generated for entries in the snmpTargetAddrTable selected by the corresponding instance of snmpNotifyTag. This value is only used when generating notifications, and is ignored when
using the snmpTargetAddrTable for other purposes.

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

messages generated for selected rows will contain

Unconfirmed-Class PDUs.

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

messages generated for selected rows will contain

Confirmed-Class PDUs.

            Note that if an SNMP entity only supports
            generation of Unconfirmed-Class PDUs (and not
            Confirmed-Class PDUs), then this object may be
            read-only."
       DEFVAL { trap }
       ::= { snmpNotifyEntry 3 }

snmpNotifyStorageType OBJECT-TYPE

       SYNTAX      StorageType
       MAX-ACCESS  read-create
       STATUS      current
       DESCRIPTION
           "The storage type for this conceptual row.
            Conceptual rows having the value 'permanent' need not
            allow write-access to any columnar objects in the row."
       DEFVAL { nonVolatile }
       ::= { snmpNotifyEntry 4 }

snmpNotifyRowStatus OBJECT-TYPE

       SYNTAX      RowStatus
       MAX-ACCESS  read-create
       STATUS      current
       DESCRIPTION
           "The status of this conceptual row.
       
            To create a row in this table, a manager must
            set this object to either createAndGo(4) or
            createAndWait(5)."
       ::= { snmpNotifyEntry 5 }

snmpNotifyFilterProfileTable OBJECT-TYPE

       SYNTAX      SEQUENCE OF SnmpNotifyFilterProfileEntry
       MAX-ACCESS  not-accessible
       STATUS      current
       DESCRIPTION
           "This table is used to associate a notification filter
            profile with a particular set of target parameters."
       ::= { snmpNotifyObjects 2 }

snmpNotifyFilterProfileEntry OBJECT-TYPE

       SYNTAX      SnmpNotifyFilterProfileEntry
       MAX-ACCESS  not-accessible
       STATUS      current
       DESCRIPTION
           "An entry in this table indicates the name of the filter
            profile to be used when generating notifications using
            the corresponding entry in the snmpTargetParamsTable.
       
            Entries in the snmpNotifyFilterProfileTable are 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 for this conceptual row.
            Conceptual rows having the value 'permanent' need not
            allow write-access to any columnar objects in the row."
       DEFVAL { nonVolatile }
       ::= { snmpNotifyFilterProfileEntry 2 }
   
   snmpNotifyFilterProfileRowStatus OBJECT-TYPE
       SYNTAX      RowStatus
       MAX-ACCESS  read-create
       STATUS      current
       DESCRIPTION
           "The status of this conceptual row.

To create a row in this table, a manager must

set this object to either createAndGo(4) or

createAndWait(5).

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

            In particular, a newly created row cannot be made
            active until the corresponding instance of
            snmpNotifyFilterProfileName has been set."
       ::= { snmpNotifyFilterProfileEntry 3 }

snmpNotifyFilterTable OBJECT-TYPE

       SYNTAX      SEQUENCE OF SnmpNotifyFilterEntry
       MAX-ACCESS  not-accessible
       STATUS      current
       DESCRIPTION
           "The table of filter profiles.  Filter profiles are used
            to determine whether particular management targets should
            receive particular notifications.

When a notification is generated, it must be compared with the filters associated with each management target which is configured to receive notifications, in order to determine whether it may be sent to each such management target.

            A more complete discussion of notification filtering
            can be found in section 6. of [SNMP-APPL]."
       ::= { 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.  A more detailed discussion of the use of this
            object can be found in section 6. of [SNMP-APPL]."
       DEFVAL { included }
       ::= { snmpNotifyFilterEntry 3 }

snmpNotifyFilterStorageType OBJECT-TYPE

       SYNTAX      StorageType
       MAX-ACCESS  read-create
       STATUS      current
       DESCRIPTION
           "The storage type for this conceptual row.
            Conceptual rows having the value 'permanent' need not
       
            allow write-access to any columnar objects in the row."
       DEFVAL { nonVolatile }
       ::= { snmpNotifyFilterEntry 4 }

snmpNotifyFilterRowStatus OBJECT-TYPE

       SYNTAX      RowStatus
       MAX-ACCESS  read-create
       STATUS      current
       DESCRIPTION
           "The status of this conceptual row.
       
            To create a row in this table, a manager must
            set this object to either createAndGo(4) or
            createAndWait(5)."
       ::= { snmpNotifyFilterEntry 5 }
   
   --
   --
   -- Conformance 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 Unconfirmed-Class notifications and
            read-create operations on only the snmpTargetAddrTable."
       MODULE SNMP-TARGET-MIB
           MANDATORY-GROUPS { snmpTargetBasicGroup }
       
           OBJECT snmpTargetParamsMPModel
           MIN-ACCESS    read-only
           DESCRIPTION
               "Create/delete/modify access is not required."
       
           OBJECT snmpTargetParamsSecurityModel
           MIN-ACCESS    read-only
           DESCRIPTION
               "Create/delete/modify access is not required."
       
           OBJECT snmpTargetParamsSecurityName
           MIN-ACCESS    read-only
           DESCRIPTION
               "Create/delete/modify access is not required."
       
           OBJECT snmpTargetParamsSecurityLevel
           MIN-ACCESS    read-only
           DESCRIPTION
               "Create/delete/modify access is not required."
       
           OBJECT snmpTargetParamsStorageType
           SYNTAX INTEGER {
               readOnly(5)
           }
           MIN-ACCESS    read-only
           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 Unconfirmed-Class notifications with filtering, and
            read-create operations on all related tables."
       MODULE SNMP-TARGET-MIB
           MANDATORY-GROUPS { snmpTargetBasicGroup }
       MODULE -- This Module
           MANDATORY-GROUPS { snmpNotifyGroup,
                              snmpNotifyFilterGroup }
       ::= { snmpNotifyCompliances 2 }

snmpNotifyFullCompliance MODULE-COMPLIANCE

       STATUS      current
       DESCRIPTION
           "The compliance statement for SNMP entities which either
            implement only SNMP Confirmed-Class notifications, or both
            SNMP Unconfirmed-Class and Confirmed-Class notifications,
       
            plus filtering and read-create operations on all related
            tables."
       MODULE SNMP-TARGET-MIB
           MANDATORY-GROUPS { snmpTargetBasicGroup,
                              snmpTargetResponseGroup }
       MODULE -- This Module
           MANDATORY-GROUPS { snmpNotifyGroup,
                              snmpNotifyFilterGroup }
       ::= { snmpNotifyCompliances 3 }

snmpNotifyGroup OBJECT-GROUP

       OBJECTS {
           snmpNotifyTag,
           snmpNotifyType,
           snmpNotifyStorageType,
           snmpNotifyRowStatus
       }
       STATUS      current
       DESCRIPTION
           "A collection of objects for selecting which 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 "200210140000Z"
       ORGANIZATION "IETF SNMPv3 Working Group"
       CONTACT-INFO
           "WG-email:   snmpv3@lists.tislabs.com
            Subscribe:  majordomo@lists.tislabs.com
                        In message body:  subscribe snmpv3
       
            Co-Chair:   Russ Mundy
                        Network Associates Laboratories
            Postal:     15204 Omega Drive, Suite 300
                        Rockville, MD 20850-4601
                        USA
            EMail:      mundy@tislabs.com
            Phone:      +1 301-947-7107
            Co-Chair:   David Harrington
                        Enterasys Networks
            Postal:     35 Industrial Way
                        P. O. Box 5004
                        Rochester, New Hampshire 03866-5005
                        USA
            EMail:      dbh@enterasys.com
            Phone:      +1 603-337-2614
       
            Co-editor:  David B. Levi
                        Nortel Networks
            Postal:     3505 Kesterwood Drive
                        Knoxville, Tennessee 37918
            EMail:      dlevi@nortelnetworks.com
            Phone:      +1 865 686 0432
       
            Co-editor:  Paul Meyer
                        Secure Computing Corporation
            Postal:     2675 Long Lake Road
                        Roseville, Minnesota 55113
            EMail:      paul_meyer@securecomputing.com
            Phone:      +1 651 628 1592
       
            Co-editor:  Bob Stewart
                        Retired"
       DESCRIPTION
           "This MIB module defines MIB objects which provide
            mechanisms to remotely configure the parameters
            used by a proxy forwarding application.
       
            Copyright © The Internet Society (2002). This
            version of this MIB module is part of RFC 3413;
            see the RFC itself for full legal notices.
           "
       REVISION    "200210140000Z"             -- 14 October 2002
       DESCRIPTION "Clarifications, published as
                    RFC 3413."
       REVISION    "199808040000Z"             -- 4 August 1998
       DESCRIPTION "Clarifications, published as
                    RFC 2573."
       REVISION    "199707140000Z"             -- 14 July 1997
       DESCRIPTION "The initial revision, published as RFC2273."
       ::= { snmpModules 14 }
   
   snmpProxyObjects        OBJECT IDENTIFIER ::= { snmpProxyMIB 1 }
   snmpProxyConformance    OBJECT IDENTIFIER ::= { snmpProxyMIB 3 }
   
   --
   --
   -- The snmpProxyObjects group
   --
   --

snmpProxyTable OBJECT-TYPE

       SYNTAX      SEQUENCE OF SnmpProxyEntry
       MAX-ACCESS  not-accessible
       STATUS      current
       DESCRIPTION
           "The table of translation parameters used by proxy forwarder
            applications for forwarding SNMP messages."
       ::= { snmpProxyObjects 2 }

snmpProxyEntry OBJECT-TYPE

       SYNTAX      SnmpProxyEntry
       MAX-ACCESS  not-accessible
       STATUS      current
       DESCRIPTION
           "A set of translation parameters used by a proxy forwarder
            application for forwarding SNMP messages.
       
            Entries in the snmpProxyTable are created and deleted
            using the snmpProxyRowStatus object."
       INDEX { IMPLIED snmpProxyName }
       ::= { snmpProxyTable 1 }
   
   SnmpProxyEntry ::= SEQUENCE {
       snmpProxyName               SnmpAdminString,
       snmpProxyType               INTEGER,
       snmpProxyContextEngineID    SnmpEngineID,
       snmpProxyContextName        SnmpAdminString,
       snmpProxyTargetParamsIn     SnmpAdminString,
       snmpProxySingleTargetOut    SnmpAdminString,
       snmpProxyMultipleTargetOut  SnmpTagValue,
       snmpProxyStorageType        StorageType,
       snmpProxyRowStatus          RowStatus
   }

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.
            Conceptual rows having the value 'permanent' need not
            allow write-access to any columnar objects in the row."
       DEFVAL { nonVolatile }
       ::= { 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 all active entries in the snmpNotifyTable to find the management targets to be used for generating notifications. Each active entry in this table selects zero or more entries in the snmpTargetAddrTable. When a notification is generated, it is sent to all of the targets specified by the selected snmpTargetAddrTable entries (subject to the application of access control and notification filtering).

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 (this allows, for example, both traps and informs to be sent to the same target).

Each snmpTargetAddrEntry contains a pointer to the snmpTargetParamsTable (snmpTargetAddrParams). This pointer selects a set of SNMP parameters to be used for generating notifications. If the selected entry in the snmpTargetParamsTable does not exist, the management target is not used to generate notifications.

The decision as to whether a notification should contain an Unconfirmed-Class or a Confirmed-Class PDU is determined by the value of the snmpNotifyType object. If the value of this object is trap(1), the notification should contain an Unconfirmed-Class PDU.

If the value of this object is inform(2), then the notification should contain a Confirmed-Class PDU, and the timeout time and number of retries for the notification are the value of snmpTargetAddrTimeout and snmpTargetAddrRetryCount. Note that the exception to these rules is when the snmpTargetParamsMPModel object indicates an SNMP version which supports a different PDU version. In this case, the notification may be sent using a different PDU type ([RFC2576] defines the PDU type in the case where the outgoing SNMP version is SNMPv1).

6. Notification Filtering

This section describes the mechanisms used by a notification originator application when using the MIB module described in this document to filter generation of notifications.

A notification originator uses the snmpNotifyFilterTable to filter notifications. A notification filter profile may be associated with a particular entry in the snmpTargetParamsTable. The associated filter profile is identified by an entry in the snmpNotifyFilterProfileTable whose index is equal to the index of the entry in the snmpTargetParamsTable. If no such entry exists in the snmpNotifyFilterProfileTable, no filtering is performed for that management target.

If such an entry does exist, the value of snmpNotifyFilterProfileName of the entry is compared with the corresponding portion of the index of all active entries in the snmpNotifyFilterTable. All such entries for which this comparison results in an exact match are used for filtering a notification generated using the associated snmpTargetParamsEntry. If no such entries exist, no filtering is performed, and a notification may be sent to the management target.

Otherwise, if matching entries do exist, a notification may be sent if the NOTIFICATION-TYPE OBJECT IDENTIFIER of the notification (this is the value of the element of the variable bindings whose name is snmpTrapOID.0, i.e., the second variable binding) is specifically included, and none of the object instances to be included in the variable-bindings of the notification are specifically excluded by the matching entries.

   Each set of snmpNotifyFilterTable entries is divided into two
   collections of filter subtrees:  the included filter subtrees, and
   the excluded filter subtrees.  The snmpNotifyFilterType object
   defines the collection to which each matching entry belongs.

To determine whether a particular notification name or object instance is excluded by the set of matching entries, compare the notification name's or object instance's OBJECT IDENTIFIER with each of the matching entries. For a notification name, if none match, then the notification name is considered excluded, and the notification should not be sent to this management target. For an object instance, if none match, the object instance is considered included, and the notification may be sent to this management target. If one or more match, then the notification name or object instance is included or excluded, according to the value of snmpNotifyFilterType in the entry whose value of snmpNotifyFilterSubtree has the most sub-identifiers. If multiple entries match and have the same number of sub-identifiers, then the value of snmpNotifyFilterType, in the entry among those which match, and whose instance is lexicographically the largest, determines the inclusion or exclusion.

A notification name or object instance's OBJECT IDENTIFIER X matches an entry in the snmpNotifyFilterTable when the number of sub- identifiers in X is at least as many as in the value of snmpNotifyFilterSubtree for the entry, and each sub-identifier in the value of snmpNotifyFilterSubtree matches its corresponding sub- identifier in X. Two sub-identifiers match either if the corresponding bit of snmpNotifyFilterMask is zero (the 'wild card' value), or if the two sub-identifiers are equal.

7. Management Target Translation in Proxy Forwarder Applications

This section describes the mechanisms used by a proxy forwarder application when using the MIB module described in this document to translate incoming management target information into outgoing management target information for the purpose of forwarding messages. There are actually two mechanisms a proxy forwarder may use, one for forwarding request messages, and one for forwarding notification messages.

7.1. Management Target Translation for Request Forwarding

When forwarding request messages, the proxy forwarder will select a single entry in the snmpProxyTable. To select this entry, it will perform the following comparisons:

• The snmpProxyType must be read(1) if the request is a Read-Class PDU. The snmpProxyType must be write(2) if the request is a Write-Class PDU.

• The contextEngineID must equal the snmpProxyContextEngineID object.

• If the snmpProxyContextName object is supported, it must equal the contextName.

• The snmpProxyTargetParamsIn object identifies an entry in the snmpTargetParamsTable. The messageProcessingModel, security model, securityName, and securityLevel must match the values of snmpTargetParamsMPModel, snmpTargetParamsSecurityModel, snmpTargetParamsSecurityName, and snmpTargetParamsSecurityLevel of the identified entry in the snmpTargetParamsTable.

There may be multiple entries in the snmpProxyTable for which these comparisons succeed. The entry whose snmpProxyName has the lexicographically smallest value and for which the comparisons succeed will be selected by the proxy forwarder.

The outgoing management target information is identified by the value of the snmpProxySingleTargetOut object of the selected entry. This object identifies an entry in the snmpTargetAddrTable. The identified entry in the snmpTargetAddrTable also contains a reference to the snmpTargetParamsTable (snmpTargetAddrParams). If either the identified entry in the snmpTargetAddrTable does not exist, or the identified entry in the snmpTargetParamsTable does not exist, then this snmpProxyEntry does not identify valid forwarding information, and the proxy forwarder should attempt to identify another row.

If there is no entry in the snmpProxyTable for which all of the conditions above may be met, then there is no appropriate forwarding information, and the proxy forwarder should take appropriate actions.

Otherwise, The snmpTargetAddrTDomain, snmpTargetAddrTAddress, snmpTargetAddrTimeout, and snmpTargetRetryCount of the identified snmpTargetAddrEntry, and the snmpTargetParamsMPModel, snmpTargetParamsSecurityModel, snmpTargetParamsSecurityName, and snmpTargetParamsSecurityLevel of the identified snmpTargetParamsEntry are used as the destination management target.

7.2. Management Target Translation for Notification Forwarding

When forwarding notification messages, the proxy forwarder will select multiple entries in the snmpProxyTable. To select these entries, it will perform the following comparisons:

• The snmpProxyType must be trap(3) if the notification is an Unconfirmed-Class PDU. The snmpProxyType must be inform(4) if the request is a Confirmed-Class PDU.

• 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, security model, securityName, and securityLevel 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:

Harald Tveit Alvestrand (Maxware)
Dave Battle (SNMP Research, Inc.)
Alan Beard (Disney Worldwide Services)
Paul Berrevoets (SWI Systemware/Halcyon Inc.)

Martin Bjorklund (Ericsson)
Uri Blumenthal (IBM T.J. Watson Research Center)
Jeff Case (SNMP Research, Inc.)
John Curran (BBN)
Mike Daniele (Compaq Computer Corporation)
T. Max Devlin (Eltrax Systems)
John Flick (Hewlett Packard)
Rob Frye (MCI)
Wes Hardaker (U.C.Davis, Information Technology - D.C.A.S.) David Harrington (Enterasys Networks)
Lauren Heintz (BMC Software, Inc.)
N.C. Hien (IBM T.J. Watson Research Center)
Michael Kirkham (InterWorking Labs, Inc.)
Dave Levi (Nortel Networks)
Louis A Mamakos (UUNET Technologies Inc.)
Joe Marzot (Nortel Networks)
Paul Meyer (Secure Computing Corporation)
Keith McCloghrie (Cisco Systems)
Bob Moore (IBM)
Russ Mundy (TIS Labs at Network Associates)
Bob Natale (ACE*COMM Corporation)
Mike O'Dell (UUNET Technologies Inc.)
Dave Perkins (DeskTalk)
Peter Polkinghorne (Brunel University)
Randy Presuhn (BMC Software, Inc.)
David Reeder (TIS Labs at Network Associates)
David Reid (SNMP Research, Inc.)
Aleksey Romanov (Quality Quorum)
Shawn Routhier (Epilogue)
Juergen Schoenwaelder (TU Braunschweig)
Bob Stewart (Cisco Systems)
Mike Thatcher (Independent Consultant)
Bert Wijnen (Lucent Technologies)

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 (Enterasys Networks)
Jeff Johnson (Cisco Systems)
David Levi (Nortel Networks)
John Linn (Openvision)
Russ Mundy (Trusted Information Systems) chair
Shawn Routhier (Epilogue)
Glenn Waters (Nortel)
Bert Wijnen (Lucent Technologies)

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 (Enterasys Networks)
David Levi (Nortel Networks)
Keith McCloghrie (Cisco Systems)
Brian O'Keefe (Hewlett Packard)
Marshall T. Rose (Dover Beach Consulting)
Jon Saperia (BGS Systems Inc.)
Steve Waldbusser (International Network Services)
Glenn W. Waters (Bell-Northern Research Ltd.)

10. Security Considerations

The SNMP applications described in this document typically have direct access to MIB instrumentation. Thus, it is very important that these applications be strict in their application of access control as described in this document.

In addition, there may be some types of notification generator applications which, rather than accessing MIB instrumentation using access control, will obtain MIB information through other means (such as from a command line). The implementors and users of such applications must be responsible for not divulging MIB information that normally would be inaccessible due to access control.

Finally, the MIBs described in this document contain potentially sensitive information. A security administrator may wish to limit access to these MIBs.

11. References

11.1 Normative References

   [RFC2119]   Bradner, S., "Key words for use in RFCs to Indicate
               Requirement Levels", BCP 14, RFC 2119, March 1997.
   
   [RFC2578]   McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J.,
               Rose, M. and S. Waldbusser, "Structure of Management
               Information Version 2 (SMIv2)", STD 58, RFC 2578, April
               1999.
   
   [RFC2579]   McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J.,
               Rose, M. and S. Waldbusser, "Textual Conventions for
               SMIv2", STD 58, RFC 2579, April 1999.
   
   [RFC2580]   McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J.,
               Rose, M. and S. Waldbusser, "Conformance Statements for
               SMIv2", STD 58, RFC 2580, April 1999.
   
   [RFC3411]   Harrington, D., Presuhn, R. and B. Wijnen, "An
               Architecture for describing Simple Network Management
               Protocol (SNMP) Management Frameworks", STD 62, RFC 3411,
               December 2002.
   
   [RFC3412]   Case, J., Harrington, D., Presuhn, R. and B. Wijnen,
               "Message Processing and Dispatching for the Simple
               Network Management Protocol (SNMP)", STD 62, RFC 3412,
               December 2002.
   
   [RFC3415]   Wijnen, B., Presuhn, R. and K. McCloghrie, "View-based
               Access Control Model (VACM) for the Simple Network
               Management Protocol (SNMP)", STD 62, RFC 3415, December
               2002.
   
   [RFC3416]   Presuhn, R., Case, J., McCloghrie, K., Rose, M. and S.
               Waldbusser, "Protocol Operations for the Simple Network
               Management Protocol (SNMP)", STD 62, RFC 3416, December
               2002.
   
   [RFC3418]   Presuhn, R., Case, J., McCloghrie, K., Rose, M. and S.
               Waldbusser, "Management Information Base (MIB) for the
               Simple Network Management Protocol (SNMP)", STD 62, RFC
               3418, December 2002.

11.2 Informative References

   [RFC1157]   Case, J., Fedor, M., Schoffstall, M. and J. Davin,
               "Simple Network Management Protocol", STD 15, RFC 1157,
               May 1990.
   
   [RFC1213]   McCloghrie, K. and M. Rose, Editors, "Management
               Information Base for Network Management of TCP/IP-based
               internets:  MIB-II", STD 17, RFC 1213, March 1991.
   
   [RFC2576]   Frye, R.,Levi, D., Routhier, S. and B. Wijnen,
               "Coexistence between Version 1, Version 2, and Version 3
               of the Internet-standard Network Management Framework",
               RFC 2576, February 1999.

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, two rows in the snmpTargetTable, and two rows in the snmpNotifyTable.

      * 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    = 128.1.5.9/162
        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

Editors' Addresses

David B. Levi
Nortel Networks
3505 Kesterwood Drive
Knoxville, TN 37918
U.S.A.

   Phone: +1 865 686 0432
   EMail: dlevi@nortelnetworks.com

Paul Meyer
Secure Computing Corporation
2675 Long Lake Road
Roseville, MN 55113
U.S.A.

   Phone: +1 651 628 1592
   EMail: paul_meyer@securecomputing.com

Bob Stewart
Retired

Full Copyright Statement

Copyright © The Internet Society (2002). All Rights Reserved.

This document and translations of it may be copied and furnished to others, and derivative works that comment on or otherwise explain it or assist in its implementation may be prepared, copied, published and distributed, in whole or in part, without restriction of any kind, provided that the above copyright notice and this paragraph are included on all such copies and derivative works. However, this document itself may not be modified in any way, such as by removing the copyright notice or references to the Internet Society or other Internet organizations, except as needed for the purpose of developing Internet standards in which case the procedures for copyrights defined in the Internet Standards process must be followed, or as required to translate it into languages other than English.

The limited permissions granted above are perpetual and will not be revoked by the Internet Society or its successors or assigns.

This document and the information contained herein is provided on an "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.

Acknowledgement

Funding for the RFC Editor function is currently provided by the Internet Society.