Event MIB and Expression MIB Enhancements

This document provides information about the several existing Simple Network Management Protocol (SNMP) MIBs that are enhanced and new SNMP MIBs that are added.

Finding Feature Information

Your software release may not support all the features documented in this module. For the latest caveats and feature information, see Bug Search Tool and the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the feature information table.

Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/​go/​cfn. An account on Cisco.com is not required.

Information about Event MIB and Expression MIB

Event MIB

The Event MIB provides the ability to monitor MIB objects on a local or remote system using the SNMP, and initiates simple actions whenever a trigger condition is met. For example, an SNMP trap can be generated when an object is modified. When the notifications are triggered through events, the NMS does not need to constantly poll managed devices to track changes.

By allowing the SNMP notifications to take place only when a specified condition is met, Event MIB reduces the load on affected devices and improves the scalability of network management solutions.

The Event MIB operates based on event, object lists configured for the event, event action, trigger, and trigger test.

Events

The event table defines the activities to be performed when an event is triggered. These activities include sending a notification and setting a MIB object. The event table has supplementary tables for additional objects that are configured according to event action. If the event action is set to notification, notifications are sent out whenever the object configured for that event is modified.

Object List

The object table lists objects that can be added to notifications based on trigger, trigger test type, or the event that sends a notification. The Event MIB allows wildcarding, which enables you to monitor multiple instances of an object. To specify a group of object identifiers, you can use the wildcard option.

Trigger

The trigger table defines conditions to trigger events. The trigger table lists the objects to be monitored and associates each trigger with an event. An event occurs when a trigger is activated. To create a trigger, you should configure a trigger entry in the mteTriggerTable of the Event MIB. This trigger entry specifies the object identifier of the object to be monitored. Each trigger is configured to monitor a single object or a group of objects specified by a wildcard (*). The Event MIB process checks the state of the monitored object at specified intervals.

Trigger Test

The trigger table has supplementary tables for additional objects that are configured based on the type of test performed for a trigger. For each trigger entry type such as existence, threshold, or Boolean, the corresponding tables (existence, threshold, and Boolean tables) are populated with the information required to perform the test. The Event MIB allows you to set event triggers based on existence, threshold, and Boolean trigger types. When the specified test on an object returns a value of true, the trigger is activated. You can configure the Event MIB to send out notifications to the interested host when a trigger is activated.

Expression MIB

The Expression MIB allows you to create expressions based on a combination of objects. The expressions are evaluated according to the sampling method. The Expression MIB supports the following types of object sampling:

  • Absolute

  • Delta

  • Changed

If there are no delta or change values in an expression, the expression is evaluated when a requester attempts to read the value of the expression. In this case, all requesters get a newly calculated value.

For expressions with delta or change values, an evaluation is performed for every sampling. In this case, requesters get the value as of the last sample period.

Absolute Sampling

Absolute sampling uses the value of the MIB object during sampling.

Delta Sampling

Delta sampling is used for expressions with counters that are identified based on delta (difference) from one sample to the next. Delta sampling requires the application to do continuous sampling, because it uses the value of the last sample.

Changed Sampling

Changed sampling uses the changed value of the object since the last sample.

How to Configure Event MIB and Expression MIB

Configuring Event MIB Using SNMP

The Event MIB can be configured using SNMP directly. In this procedure, the Event MIB is configured to monitor the delta values of ifInOctets for all interfaces once per minute. If any of the samples exceed the specified threshold, a trap notification will be sent.

There are no Cisco software configuration tasks associated with the Event MIB. All configuration of Event MIB functionality must be performed though applications using SNMP. This section provides a sample configuration session using a network management application on an external device. See the “Additional References” section for information about configuring SNMP on your Cisco routing device.

All configuration of Event MIB functionality must be performed though applications using SNMP. The following section provides a step-by-step Event MIB configuration using SNMP research tools available for Sun workstations. The setany commands given below are executed using the SNMP application.


Note

These are not Cisco command line interface commands. It is assumed that SNMP has been configured on your routing device.

In this configuration, the objective is to monitor ifInOctets for all interfaces. The Event MIB is configured to monitor the delta values of ifInOctets for all interfaces once per minute. If any of the samples exceed the specified threshold of 30, a Trap notification will be sent.

There are five parts to the following example:

Setting the Trigger in the Trigger Table

Perform this task to set the trigger in the trigger table.

SUMMARY STEPS

    1.    setany -v2c $ADDRESS private mteTriggerEntryStatus.4.106.111.104.110.1 -i 5

    2.    setany -v2c $ADDRESS private mteTriggerValueID.4.106.111.104.110.1 -d 1.3.6.1.2.1.2.2.1.10

    3.    setany -v2c $ADDRESS private mteTriggerValueIDWildcard.4.106.111.104.110.1 -i 1

    4.    setany -v2c $ADDRESS private mteTriggerTest.4.106.111.104.110.1 -o '20'

    5.    setany -v2c $ADDRESS private mteTriggerFrequency.4.106.111.104.110.1 -g 60

    6.    setany -v2c $ADDRESS private mteTriggerSampleType.4.106.111.104.110.1 -i 2

    7.    setany -v2c $ADDRESS private mteTriggerEnabled.4.106.111.104.110.1 -i 1


DETAILED STEPS
     Command or ActionPurpose
    Step 1 setany -v2c $ADDRESS private mteTriggerEntryStatus.4.106.111.104.110.1 -i 5
     

    Creates a trigger row in the table with john as the mteOwner and 1 as the trigger name.

    • The index is given in decimal representation of the ASCII value of john.1.

     
    Step 2 setany -v2c $ADDRESS private mteTriggerValueID.4.106.111.104.110.1 -d 1.3.6.1.2.1.2.2.1.10
     

    Sets the mteTriggerValueID to the OID to be watched.

    • In this example, the OID to be monitored is ifInOctets.

     
    Step 3 setany -v2c $ADDRESS private mteTriggerValueIDWildcard.4.106.111.104.110.1 -i 1
     

    Sets the mteTriggerValueIDWildcard to TRUE to denote a object referenced through wildcarding.

     
    Step 4 setany -v2c $ADDRESS private mteTriggerTest.4.106.111.104.110.1 -o '20'
     

    Sets the mteTriggerTest to Threshold.

     
    Step 5 setany -v2c $ADDRESS private mteTriggerFrequency.4.106.111.104.110.1 -g 60
     

    Sets the mteTriggerFrequency to 60. This means that ifInOctets are monitored once every 60 seconds.

     
    Step 6 setany -v2c $ADDRESS private mteTriggerSampleType.4.106.111.104.110.1 -i 2
     

    Sets the sample type to Delta.

     
    Step 7 setany -v2c $ADDRESS private mteTriggerEnabled.4.106.111.104.110.1 -i 1
     

    Enables the trigger.

     

    Creating an Event in the Event Table

    Perform this task to create an event in the event table.

    SUMMARY STEPS

      1.    setany -v2c $ADDRESS private mteEventEntryStatus.4.106.111.104.110.101.118.101.110. 116 -i 5

      2.    setany -v2c $ADDRESS private mteEventEnabled.4.106.111.104.110.101.118.101.110.116 -i 1

      3.    setany -v2c $ADDRESS private mteEventEntryStatus.4.106.111.104.110.101.118.101.110. 116 -i 1


    DETAILED STEPS
       Command or ActionPurpose
      Step 1 setany -v2c $ADDRESS private mteEventEntryStatus.4.106.111.104.110.101.118.101.110. 116 -i 5
       

      Creates a row in the Event Table.

      • The mteOwner here is again john, and the event is mteEventName.

      • The default action is to send out a notification.

       
      Step 2 setany -v2c $ADDRESS private mteEventEnabled.4.106.111.104.110.101.118.101.110.116 -i 1
       

      Enables the Event.

       
      Step 3 setany -v2c $ADDRESS private mteEventEntryStatus.4.106.111.104.110.101.118.101.110. 116 -i 1
       

      Makes the EventRow active.

       

      Setting and Activating the Trigger Threshold in the Trigger Table

      Perform this task to set the trigger threshold in the trigger table.

      SUMMARY STEPS

        1.    setany -v2c $ADDRESS private mteTriggerThresholdRising.4.106.111.104.110.1 -i 30

        2.    setany -v2c $ADDRESS private mteTriggerThresholdRisingEventOwner.4.106.111.104.110.1 -D "owner"

        3.    setany -v2c $ADDRESS private mteTriggerEntryStatus.4.106.111.104.110.1 -i 1


      DETAILED STEPS
         Command or ActionPurpose
        Step 1 setany -v2c $ADDRESS private mteTriggerThresholdRising.4.106.111.104.110.1 -i 30
         

        Sets the Rising Threshold value to 30. Note that a row would already exist for john.1 in the Trigger Threshold Table.

         
        Step 2 setany -v2c $ADDRESS private mteTriggerThresholdRisingEventOwner.4.106.111.104.110.1 -D "owner"


        Example:
        setany -v2c $ADDRESS private mteTriggerThresholdRisingEvent.4.106.111.104.110.1 -D "event"
         

        Points to the entry in the Event Table that specifies the action to be performed.

         
        Step 3setany -v2c $ADDRESS private mteTriggerEntryStatus.4.106.111.104.110.1 -i 1
         

        Makes the trigger active.

         
        What to Do Next

        To confirm that the above configuration is working, ensure that at least one of the interfaces gets more than 30 packets in a minute. This should cause a trap to be sent out after one minute.

        Monitoring and Maintaining Event MIB

        Use the following commands to monitor Event MIB activity from the Cisco command line interface:

        Command

        Purpose

        debug management event mib

        Prints messages to the screen whenever the Event MIB evaluates a specified trigger. These messages are given in realtime and are intended to be used by technical support engineers for troubleshooting purposes.

        show management event

        Displays the SNMP Event values that have been configured on your routing device through the use of the Event MIB.

        Configuring Event MIB Using Command Line Interface

        The Event MIB can be configured using SNMP directly. In this procedure, the Event MIB is configured to monitor delta values of ifInOctets for all interfaces once per minute. If any of the samples exceed the specified threshold, a trap notification will be sent.

        Depending on your release, note that the Event MIB feature is enhanced to add command line interface commands to configure the events, event action, and trigger.

        This section contains the following tasks to configure the Event MIB:

        Configuring Scalar Variables

        Perform this task to configure scalar variables for Event MIB.

        Before You Begin

        To configure the scalar variables for Event MIB, you should be familiar with the Event MIB scalar variables.

        SUMMARY STEPS

          1.    enable

          2.    configure terminal

          3.    snmp mib event sample minimum value

          4.    snmp mib event sample instance maximum value

          5.    end


        DETAILED STEPS
           Command or ActionPurpose
          Step 1 enable


          Example:
          Device> enable
           

          Enables privileged EXEC mode.

          • Enter your password if prompted.

           
          Step 2 configure terminal


          Example:
          Device# configure terminal
           

          Enters global configuration mode.

           
          Step 3 snmp mib event sample minimum value


          Example:
          Device(config)# snmp mib event sample minimum 10
           

          Sets the minimum value for object sampling.

           
          Step 4 snmp mib event sample instance maximum value


          Example:
          Device(config)# snmp mib event sample instance maximum 50
           

          Sets the maximum value for object instance sampling.

           
          Step 5 end


          Example:
          Device(config)# end
           

          Exits global configuration mode and enters privileged EXEC mode.

           

          Configuring Event MIB Object List

          To configure the Event MIB, you need to set up a list of objects that can be added to notifications according to the trigger, trigger test, or event.

          Before You Begin

          To configure the Event MIB object list, you should be familiar with the Event MIB objects and object identifiers, which can be added to notifications according to the event, trigger, or trigger test.

          SUMMARY STEPS

            1.    enable

            2.    configure terminal

            3.    snmp mib event object list owner object-list-owner name object-list-name object-number

            4.    object id object-identifier

            5.    wildcard

            6.    end


          DETAILED STEPS
             Command or ActionPurpose
            Step 1 enable


            Example:
            Device> enable
             

            Enables privileged EXEC mode.

            • Enter your password if prompted.

             
            Step 2 configure terminal


            Example:
            Device# configure terminal
             

            Enters global configuration mode.

             
            Step 3 snmp mib event object list owner object-list-owner name object-list-name object-number


            Example:
            Device(config)# snmp mib event object list owner owner1 name objectA 10
             

            Configures the Event MIB object list.

             
            Step 4 object id object-identifier


            Example:
            Device(config-event-objlist)# object id ifInOctets
             

            Specifies the object identifier for the object configured for the event.

             
            Step 5 wildcard


            Example:
            Device(config-event-objlist)# wildcard
             

            (Optional) Starts a wildcard search for object identifiers. By specifying a partial object identifier, you can obtain a list of object identifiers.

             
            Step 6 end


            Example:
            Device(config-event-objlist)# end
             

            Exits object list configuration mode.

             

            Configuring Event

            Perform this task to configure a management event.

            Before You Begin

            To configure a management event, you should be familiar with SNMP MIB events and object identifiers.

            SUMMARY STEPS

              1.    enable

              2.    configure terminal

              3.    snmp mib event owner event-owner name event-name

              4.    description event-description

              5.    enable

              6.    end


            DETAILED STEPS
               Command or ActionPurpose
              Step 1 enable


              Example:
              Device> enable
               

              Enables privileged EXEC mode.

              • Enter your password if prompted.

               
              Step 2 configure terminal


              Example:
              Device# configure terminal
               

              Enters global configuration mode.

               
              Step 3 snmp mib event owner event-owner name event-name


              Example:
              Device(config)# snmp mib event owner owner1 event EventA
               

              Enters event configuration mode.

               
              Step 4 description event-description


              Example:
              Device(config-event)# description "EventA is an RMON event"
               

              Describes the function and use of the event.

               
              Step 5 enable


              Example:
              Device(config-event)# enable
               

              Enables the event.

              Note   

              The event can be executed during an event trigger only if it is enabled.

               
              Step 6 end


              Example:
              Device(config-event)# end
               

              Exits event configuration mode.

               

              Configuring Event Action

              By configuring an event action, you can define the actions that an application can perform during an event trigger. The actions for an event include sending a notification, setting a MIB object and so on. You can set the event action information to either set or notification. The actions for the event can be configured only in event configuration mode.

              The following sections contain the tasks to configure an event action:

              Configuring Action Notification

              Perform this task to set the notification action for the event.

              SUMMARY STEPS

                1.    enable

                2.    configure terminal

                3.    snmp mib event owner event-owner name event-name

                4.    action notification

                5.    object id object-id

                6.    end


              DETAILED STEPS
                 Command or ActionPurpose
                Step 1 enable


                Example:
                Device> enable
                 

                Enables privileged EXEC mode.

                • Enter your password if prompted.

                 
                Step 2 configure terminal


                Example:
                Device# configure terminal
                 

                Enters global configuration mode.

                 
                Step 3 snmp mib event owner event-owner name event-name


                Example:
                Device(config)# snmp mib event owner owner1 name test
                 

                Enters event configuration mode.

                 
                Step 4 action notification


                Example:
                Device(config-event)# action notification
                 

                Sets the notification action for an event and enters action notification configuration mode.

                Note   

                If the event action is set to notification, a notification is generated whenever an object associated with an event is modified.

                 
                Step 5 object id object-id


                Example:
                Device(config-event-action-notification)# object id ifInOctets
                 

                Configures an object for action notification. When the object specified is modified, a notification will be sent to the host system.

                 
                Step 6 end


                Example:
                Device(config-event-action-notification)# end
                 

                Exits action notification configuration mode.

                 
                Configuring Action Set

                Perform this task to set actions for an event.

                SUMMARY STEPS

                  1.    action set

                  2.    object id object-id

                  3.    value integer-value

                  4.    end


                DETAILED STEPS
                   Command or ActionPurpose
                  Step 1 action set


                  Example:
                  Device(config-event)# action set
                   

                  Enters action set configuration mode.

                   
                  Step 2 object id object-id


                  Example:
                  Device(config-event-action-set)# object id ifInOctets
                   

                  Configures an object for action set.

                  • When the object specified is modified, a specified action will be performed.

                   
                  Step 3 value integer-value


                  Example:
                  Device(config-event-action-set)# value 10
                   

                  Sets a value for the object.

                   
                  Step 4 end


                  Example:
                  Device(config-event-action-set)# end
                   

                  Exits action set configuration mode.

                   

                  Configuring Event Trigger

                  By configuring an event trigger, you can list the objects to monitor, and associate each trigger to an event.

                  Perform this task to configure an event trigger.

                  SUMMARY STEPS

                    1.    enable

                    2.    configure terminal

                    3.    snmp mib event trigger owner trigger-owner name trigger-name

                    4.    description trigger-description

                    5.    frequency seconds

                    6.    object list owner object-list-owner name object-list-name

                    7.    object id object-identifier

                    8.    enable

                    9.    end


                  DETAILED STEPS
                     Command or ActionPurpose
                    Step 1 enable


                    Example:
                    Device> enable
                     

                    Enables privileged EXEC mode.

                    • Enter your password if prompted.

                     
                    Step 2 configure terminal


                    Example:
                    Device# configure terminal
                     

                    Enters global configuration mode.

                     
                    Step 3 snmp mib event trigger owner trigger-owner name trigger-name


                    Example:
                    Device(config)# snmp mib event trigger owner owner1 name EventTriggerA
                     

                    Enables event trigger configuration mode for the specified event trigger.

                     
                    Step 4 description trigger-description


                    Example:
                    Device(config-event-trigger)# description “EventTriggerA is an RMON alarm.”
                     

                    Describes the function and use of the event trigger.

                     
                    Step 5 frequency seconds


                    Example:
                    Device(config-event-trigger)# frequency 120
                     

                    Configures the waiting time (number of seconds) between trigger samples.

                     
                    Step 6 object list owner object-list-owner name object-list-name


                    Example:
                    Device(config-event-trigger)# object list owner owner1 name ObjectListA
                     

                    Specifies the list of objects that can be added to notifications.

                     
                    Step 7 object id object-identifier


                    Example:
                    Device(config-event-trigger)# object id ifInOctets
                     

                    Configures object identifiers for an event trigger.

                     
                    Step 8 enable


                    Example:
                    Device(config-event-trigger)# enable
                     

                    Enables the event trigger.

                     
                    Step 9 end


                    Example:
                    Device(config-event-trigger)# end
                     

                    Exits event trigger configuration mode.

                     

                    Configuring Existence Trigger Test

                    You should configure this trigger type in event trigger configuration mode.

                    Perform this task to configure trigger parameters for the test existence trigger type.

                    SUMMARY STEPS

                      1.    test existence

                      2.    event owner event-owner name event-name

                      3.    object list owner object-list-owner name object-list-name

                      4.    type {present | absent | changed}

                      5.    startup {present | absent}

                      6.    end


                    DETAILED STEPS
                       Command or ActionPurpose
                      Step 1 test existence


                      Example:
                      Device(config-event-trigger)# test existence
                       

                      Enables test existence configuration mode.

                       
                      Step 2 event owner event-owner name event-name


                      Example:
                      Device(config-event-trigger-existence)# event owner owner1 name EventA
                       

                      Configures the event for the existence trigger test.

                       
                      Step 3 object list owner object-list-owner name object-list-name


                      Example:
                      Device(config-event-trigger-existence)# object list owner owner1 name ObjectListA
                       

                      Configures the list of objects for the existence trigger test.

                       
                      Step 4 type {present | absent | changed}


                      Example:
                      Device(config-event-trigger-existence)# type present
                       

                      Performs the specified type of existence test.

                      Existence tests are of the following three types:

                      • Present—Setting type to present tests if the objects that appear during the event trigger exist.

                      • Absent—Setting type to absent tests if the objects that disappear during the event trigger exist.

                      • Changed—Setting type to changed tests if the objects that changed during the event trigger exist.

                       
                      Step 5 startup {present | absent}


                      Example:
                      Device(config-event-trigger-existence)# startup present
                       

                      Triggers an event if the test is performed successfully.

                       
                      Step 6 end


                      Example:
                      Device(config-event-trigger-existence)# end
                       

                      Exits existence trigger test configuration mode.

                       

                      Configuring Boolean Trigger Test

                      You should configure this trigger test in event trigger configuration mode.

                      Perform this task to configure trigger parameters for the Boolean trigger type.

                      SUMMARY STEPS

                        1.    test boolean

                        2.    comparison {unequal | equal | less | lessOrEqual | greater | greaterOrEqual}

                        3.    value integer-value

                        4.    object list owner object-list-owner name object-list-name

                        5.    event owner event-owner name event-name

                        6.    startup

                        7.    end


                      DETAILED STEPS
                         Command or ActionPurpose
                        Step 1 test boolean


                        Example:
                        Device(config-event-trigger)# test boolean
                         

                        Enables Boolean trigger test configuration mode.

                         
                        Step 2 comparison {unequal | equal | less | lessOrEqual | greater | greaterOrEqual}


                        Example:
                        Device(config-event-trigger-boolean)# comparison unequal
                         

                        Performs the specified Boolean comparison test.

                        • The value for the Boolean comparison test can be set to unequal, equal, less, lessOrEqual, greater, or greaterOrEqual.

                         
                        Step 3 value integer-value


                        Example:
                        Device(config-event-trigger-boolean)# value 10
                         

                        Sets a value for the Boolean trigger test.

                         
                        Step 4 object list owner object-list-owner name object-list-name


                        Example:
                        Device(config-event-trigger-boolean)# object list owner owner1 name ObjectListA
                         

                        Configures the list of objects for the Boolean trigger test.

                         
                        Step 5 event owner event-owner name event-name


                        Example:
                        Device(config-event-trigger-boolean)# event owner owner1 name EventA
                         

                        Configures the event for the Boolean trigger type.

                         
                        Step 6 startup


                        Example:
                        Device(config-event-trigger-boolean)# startup
                         

                        Triggers an event if the test is performed successfully.

                         
                        Step 7 end


                        Example:
                        Device(config-event-trigger-boolean)# end
                         

                        Exits Boolean trigger test configuration mode.

                         

                        Configuring Threshold Trigger Test

                        You should configure this trigger test in event trigger configuration mode.

                        Perform this task to configure trigger parameters for the threshold trigger test.

                        SUMMARY STEPS

                          1.    test threshold

                          2.    object list owner object-list-owner name object-list-name

                          3.    rising integer-value

                          4.    rising event owner event-owner name event-name

                          5.    falling integer-value

                          6.    falling event owner event-owner name event-name

                          7.    delta rising integer-value

                          8.    delta rising event owner event-owner name event-name

                          9.    delta falling integer-value

                          10.    delta falling event owner event-owner name event-name

                          11.    startup {rising | falling | rising-or-falling}

                          12.    end


                        DETAILED STEPS
                           Command or ActionPurpose
                          Step 1 test threshold


                          Example:
                          Device(config-event-trigger)# test threshold
                           

                          Enables threshold trigger test configuration mode.

                           
                          Step 2 object list owner object-list-owner name object-list-name


                          Example:
                          Device(config-event-trigger-threshold)# object list owner owner1 name ObjectListA
                           

                          Configures the list of objects for the threshold trigger test.

                           
                          Step 3 rising integer-value


                          Example:
                          Device(config-event-trigger-threshold)# rising 100
                           

                          Sets the rising threshold to the specified value.

                           
                          Step 4 rising event owner event-owner name event-name


                          Example:
                          Device(config-event-trigger-threshold)# rising event owner owner1 name EventA
                           

                          Configures an event for the threshold trigger test for the rising threshold.

                           
                          Step 5 falling integer-value


                          Example:
                          Device(config-event-trigger-threshold)# falling 50
                           

                          Sets the falling threshold to the specified value.

                           
                          Step 6 falling event owner event-owner name event-name


                          Example:
                          Device(config-event-trigger-threshold)# falling event owner owner1 name EventB
                           

                          Configures an event for the threshold trigger test for the falling threshold.

                           
                          Step 7 delta rising integer-value


                          Example:
                          Device(config-event-trigger-threshold)# delta rising 30
                           

                          Sets the delta rising threshold to the specified value when the sampling method specified for the event trigger is delta.

                           
                          Step 8 delta rising event owner event-owner name event-name


                          Example:
                          Device(config-event-trigger-threshold)# delta rising event owner owner1 name EventC
                           

                          Configures an event for the threshold trigger test for the delta rising threshold.

                           
                          Step 9 delta falling integer-value


                          Example:
                          Device(config-event-trigger-threshold)# delta falling 10
                           

                          Sets the delta falling threshold to the specified value when the sampling method specified for the event trigger is delta.

                           
                          Step 10 delta falling event owner event-owner name event-name


                          Example:
                          Device(config-event-trigger-threshold)# delta falling event owner owner1 name EventAA
                           

                          Configures an event for the threshold target test for the delta falling threshold.

                           
                          Step 11 startup {rising | falling | rising-or-falling}


                          Example:
                          Device(config-event-trigger-threshold)# startup rising
                           

                          Triggers an event when the threshold trigger test conditions are met.

                           
                          Step 12 end


                          Example:
                          Device(config-event-trigger-threshold)# end
                           

                          Exits threshold trigger test configuration mode.

                           

                          Configuring Expression MIB Using SNMP

                          Expression MIB can be configured using SNMP directly.

                          There are no Cisco software configuration tasks associated with Expression MIB. All configurations of the Expression MIB functionality must be performed though applications using SNMP. This section provides a sample configuration session using a network management application on an external device. See the Additional References section for information about configuring SNMP on your Cisco routing device.

                          The following section provides a step-by-step Expression MIB configuration using SNMP research tools available for Sun workstations. The setany commands given below are executed using the SNMP application. Note that these commands are not Cisco command line interface commands. It is assumed that SNMP has been configured on your routing device.

                          In the following configuration, a wildcarded expression involving the addition of the counters ifInOctects and ifOutOctects are evaluated.

                          SUMMARY STEPS

                            1.    setany -v2c $SNMP_HOST private expResourceDeltaMinimum.0 -i 60

                            2.    setany -v2c $SNMP_HOST private expExpressionIndex.116.101.115.116 -g 9

                            3.    setany -v2c $SNMP_HOST private expNameStatus.116.101.115.116 -i 5

                            4.    setany -v2c $SNMP_HOST private expExpressionComment.9 -D "test expression"

                            5.    setany -v2c $SNMP_HOST private expExpression.9 -D '$1 + $2'

                            6.    setany -v2c $SNMP_HOST private expObjectID.9.1 -d ifInOctets

                            7.    setany -v2c $SNMP_HOST private expObjectSampleType.9.1 -i 2

                            8.    setany -v2c $SNMP_HOST private expObjectIDWildcard.9.1 -i 1

                            9.    setany -v2c $SNMP_HOST private expObjectStatus.9.1 -i 1

                            10.    setany -v2c $SNMP_HOST private expNameStatus.116.101.115.116 -i 1


                          DETAILED STEPS
                             Command or ActionPurpose
                            Step 1 setany -v2c $SNMP_HOST private expResourceDeltaMinimum.0 -i 60
                             

                            Sets the minimum delta interval that the system will accept.

                             
                            Step 2 setany -v2c $SNMP_HOST private expExpressionIndex.116.101.115.116 -g 9
                             

                            Sets the identification number used for identifying the expression.

                            • For example, expName can be 'test', which is ASCII 116.101.115.116.

                             
                            Step 3 setany -v2c $SNMP_HOST private expNameStatus.116.101.115.116 -i 5
                             

                            Creates an entry in the expNameStatusTable.

                            Note   

                            When an entry is created in the expNameTable, it automatically creates an entry in the expExpressionTable.

                             
                            Step 4 setany -v2c $SNMP_HOST private expExpressionComment.9 -D "test expression"
                             

                            Sets the object to a comment to explain the use or meaning of the expression.

                            • Here, the comment is "test expression".

                             
                            Step 5 setany -v2c $SNMP_HOST private expExpression.9 -D '$1 + $2'
                             

                            Sets the object expExpression to an expression that needs to be evaluated.

                            • In this expression, "$1" corresponds to "ifInOctets", "$2" corresponds to "ifOutOctets", and the expression signifies the addition of the two counter objects.

                             
                            Step 6 setany -v2c $SNMP_HOST private expObjectID.9.1 -d ifInOctets


                            Example:
                            setany -v2c $SNMP_HOST private expObjectID.9.2 -d ifOutOctets
                             

                            Specifies the object identifiers used in the expression mentioned in the above set for calculation.

                            • Here, the number "9", suffixed to the object expObjectID, corresponds to the unique identifier used for identifying the expression, and the number "1" following "9" is another unique identifier used for identifying an object within the expression. Set the expObjectID to the two objects used in forming the expression.

                             
                            Step 7 setany -v2c $SNMP_HOST private expObjectSampleType.9.1 -i 2


                            Example:
                            setany -v2c $SNMP_HOST private expObjectSampleType.9.2 -i 2
                             

                            Sets the type of sampling to be done for objects in the expression.

                            • There are two types of sampling: a) Absolute b) Delta. Here, the sample type has been set to "Delta".

                             
                            Step 8 setany -v2c $SNMP_HOST private expObjectIDWildcard.9.1 -i 1


                            Example:
                            setany -v2c $SNMP_HOST private expObjectIDWildcard.9.2 -i 1
                             

                            Specifies whether the expObjectID is wildcarded or not. In this case, both the expObjectID are wildcarded.

                             
                            Step 9 setany -v2c $SNMP_HOST private expObjectStatus.9.1 -i 1


                            Example:
                            setany -v2c $SNMP_HOST private expObjectStatus.9.2 -i 1
                             

                            Sets the rows in the expObjectTable to active.

                             
                            Step 10 setany -v2c $SNMP_HOST private expNameStatus.116.101.115.116 -i 1
                             

                            Sets the rows in the expNameTable to active so that the value of the expression can be evaluated.

                            • The value of the expression can now be obtained from the expValueTable.

                             

                            Configuring Expression MIB Using Command Line Interface

                            Expression MIB can be configured using SNMP directly. Depending on your release, you can find that the Expression MIB feature is enhanced to add command line interface commands to configure expressions. You should be familiar with expressions, object identifiers, and sampling methods before configuring Expression MIB.

                            The following sections contain the tasks to configure Expression MIB:

                            Configuring Expression MIB Scalar Objects

                            Expression MIB has the following scalar objects:

                            • expResourceDeltaMinimum

                            • expResourceDeltaWildcardInstanceMaximum

                            Perform this task to configure Expression MIB scalar objects.

                            SUMMARY STEPS

                              1.    enable

                              2.    configure terminal

                              3.    snmp mib expression delta minimum seconds

                              4.    snmp mib expression delta wildcard maximum number-of-instances

                              5.    end


                            DETAILED STEPS
                               Command or ActionPurpose
                              Step 1 enable


                              Example:
                              Device> enable
                               

                              Enables privileged EXEC mode.

                              • Enter your password if prompted.

                               
                              Step 2 configure terminal


                              Example:
                              Device# configure terminal
                               

                              Enters global configuration mode.

                               
                              Step 3 snmp mib expression delta minimum seconds


                              Example:
                              Device(config)# snmp mib expression delta minimum 20
                               

                              (Optional) Sets the minimum delta interval in seconds.

                              Note   

                              Application may use larger values for this minimum delta interval to lower the impact of constantly computing deltas. For larger delta sampling intervals, the application samples less often and has less overhead. By using this command, you can enforce a lower overhead for all expressions created after the delta interval is set.

                               
                              Step 4 snmp mib expression delta wildcard maximum number-of-instances


                              Example:
                              Device(config)# snmp mib expression delta maximum 120
                               

                              (Optional) Limits the maximum number of dynamic instance entries for wildcard delta objects in expressions.

                              • For a given delta expression, the number of dynamic instances is the number of values that meet all criteria to exist, times the number of delta values in the expression.

                              • There is no preset limit for the instance entries and it is dynamic based on a system’s resources.

                               
                              Step 5 end


                              Example:
                              Device(config)# end
                               

                              Exits global configuration mode.

                               

                              Configuring Expressions

                              Perform this task to configure an expression.

                              SUMMARY STEPS

                                1.    enable

                                2.    configure terminal

                                3.    snmp mib expression owner expression-owner name expression-name

                                4.    description expression-description

                                5.    expression expression

                                6.    delta interval seconds

                                7.    value type {counter32 | unsigned32 | timeticks | integer32 | ipaddress | octetstring | objectid | counter64}

                                8.    enable

                                9.    object object-number

                                10.    id object-identifier

                                11.    wildcard

                                12.    discontinuity object discontinuity-object-id [wildcard] [type {timeticks | timestamp | date-and-time}]

                                13.    conditional object conditional-object-id [wildcard]

                                14.    sample {absolute | delta | changed}

                                15.    end


                              DETAILED STEPS
                                 Command or ActionPurpose
                                Step 1 enable


                                Example:
                                Device> enable
                                 

                                Enables privileged EXEC mode.

                                • Enter your password if prompted.

                                 
                                Step 2 configure terminal


                                Example:
                                Device# configure terminal
                                 

                                Enters global configuration mode.

                                 
                                Step 3 snmp mib expression owner expression-owner name expression-name


                                Example:
                                Device(config-expression)# snmp mib expression owner owner1 name ExpA
                                 

                                Enables the expression to be configured.

                                 
                                Step 4 description expression-description


                                Example:
                                Device(config-expression)# description this expression is created for the sysLocation MIB object
                                 

                                Configures a description for the expression.

                                 
                                Step 5 expression expression


                                Example:
                                Device(config-expression)# expression ($1+$2)*800/$3
                                 

                                Configures the expression to be evaluated.

                                Note   

                                The expressions are in ANSI C syntax. However, the variables in an expression are defined as a combination of the dollar sign ($) and an integer that corresponds to the object number of the object used in evaluating the expression.

                                 
                                Step 6 delta interval seconds


                                Example:
                                Device(config-expression)# delta interval 180
                                 

                                Configures the sampling interval for objects in the expression if the sampling method is delta.

                                 
                                Step 7 value type {counter32 | unsigned32 | timeticks | integer32 | ipaddress | octetstring | objectid | counter64}


                                Example:
                                Device(config-expression)# value type counter32
                                 

                                Sets the specified value type for the expression.

                                 
                                Step 8 enable


                                Example:
                                Device(config-expression)# enable
                                 

                                Enables an expression for evaluation.

                                 
                                Step 9 object object-number


                                Example:
                                Device(config-expression)# object 2
                                 

                                Configures the objects that are used for evaluating an expression.

                                • The object number is used to associate the object with the variables in the expression. The variable corresponding to the object is $ and object number. Thus, the variable in the example used here corresponds to $10.

                                 
                                Step 10 id object-identifier


                                Example:
                                Device(config-expression-object)# id ifInOctets
                                 

                                Configures the object identifier.

                                 
                                Step 11 wildcard


                                Example:
                                Device(config-expression-object)# wildcard
                                 

                                (Optional) Enables a wildcarded search for objects used in evaluating an expression.

                                 
                                Step 12 discontinuity object discontinuity-object-id [wildcard] [type {timeticks | timestamp | date-and-time}]


                                Example:
                                Device(config-expression-object)# discontinuity object sysUpTime
                                 

                                (Optional) Configures the discontinuity properties for the object if the object sampling type is set to delta or changed. The discontinuity object ID supports normal checking for a discontinuity in a counter.

                                • Using the wildcard keyword, you can enable wildcarded search for objects with discontinuity properties.

                                • Using the type keyword, you can set value for objects with discontinuity properties.

                                 
                                Step 13 conditional object conditional-object-id [wildcard]


                                Example:
                                Device(config-expression-object)# conditional object mib-2.90.1.3.1.1.2.3.112.99.110.4.101.120.112.53
                                 

                                (Optional) Configures the conditional object identifier.

                                • Using the wildcard keyword, you can enable a wildcarded search for conditional objects with discontinuity properties.

                                 
                                Step 14 sample {absolute | delta | changed}


                                Example:
                                Device(config-expression-object)# sample delta
                                 

                                Enables the specified sampling method for the object. This example uses the delta sampling method.

                                You can set any of the three sampling methods: absolute, delta, and changed.

                                • Absolute sampling—Uses the value of the MIB object during sampling.

                                • Delta sampling—Uses the last sampling value maintained in the application. This method requires applications to do continuous sampling.

                                • Changed sampling—Uses the changed value of the object since the last sample.

                                 
                                Step 15 end


                                Example:
                                Device(config-expression-object)# end
                                 

                                Exits expression object configuration mode.

                                 

                                Configuration Examples for Event MIB and Expression MIB

                                Example: Configuring Event MIB from SNMP

                                The following example shows how to configure scalar variables for an event: 

                                Device# configure terminal
Device(config)# snmp mib event sample minimum 10
Device(config)# snmp mib event sample instance maximum 50
Device(config)# end

                                The following example shows how to configure object list for an event: 

                                Device# configure terminal
Device(config)# snmp mib event object list owner owner1 name objectA number 1
Device(config-event-objlist)# object id ifInOctets
Device(config-event-objlist)# wildcard
Device(config-event-objlist)# end

                                The following example shows how to configure an event: 

                                Device# configure terminal
Device(config)# snmp mib event owner owner1 event EventA
Device(config-event)# description “eventA is an RMON event.”
Device(config-event)# enable
Device(config-event)# end

                                The following example shows how to set the notification action for an event: 

                                Device(config-event)# action notification
Device(config-event-action-notification)# object id ifInOctets
Device(config-event-action-notification)# end

                                The following example shows how to set actions for an event: 

                                Device(config-event)# action set
Device(config-event-action-set)# object id ifInOctets
Device(config-event-action-set)# value 10
Device(config-event-action-set)# end

                                The following example shows how to configure trigger for an event: 

                                Device# configure terminal
Device(config)# snmp mib event trigger owner owner1 name EventTriggerA
Device(config-event-trigger)# description EventTriggerA is an RMON alarm.
Device(config-event-trigger)# frequency 120
Device(config-event-trigger)# object list owner owner1 name ObjectListA
Device(config-event-trigger)# object id ifInOctets
Device(config-event-trigger)# enable
Device(config-event-trigger)# end

                                The following example shows how to configure existence trigger test: 

                                Device(config-event-trigger)# test existence
Device(config-event-trigger-existence)# event owner owner1 name EventA
Device(config-event-trigger-existence)# object list owner owner1 name ObjectListA
Device(config-event-trigger-existence)# type present
Device(config-event-trigger-existence)# startup present
Device(config-event-trigger-existence)# end

                                The following example shows how to configure Boolean trigger test: 

                                Device(config-event-trigger)# test boolean
Device(config-event-trigger-boolean)# comparison unequal
Device(config-event-trigger-boolean)# value 10
Device(config-event-trigger-boolean)# object list owner owner1 name ObjectListA
Device(config-event-trigger-boolean)# event owner owner1 name EventA
Device(config-event-trigger-boolean)# startup
Device(config-event-trigger-boolean)# end

                                The following example shows how to configure threshold trigger test: 

                                Device(config-event-trigger)# test threshold
Device(config-event-trigger-threshold)# object list owner owner1 name ObjectListA
Device(config-event-trigger-threshold)# rising 100
Device(config-event-trigger-threshold)# rising event owner owner1 name EventA
Device(config-event-trigger-threshold)# falling 50
Device(config-event-trigger-threshold)# falling event owner owner1 name EventA
Device(config-event-trigger-threshold)# delta rising 30
Device(config-event-trigger-threshold)# delta rising event owner owner1 name EventA
Device(config-event-trigger-threshold)# delta falling 10
Device(config-event-trigger-threshold)# delta falling event owner owner1 name EventA
Device(config-event-trigger-threshold)# startup rising
Device(config-event-trigger-threshold)# end

                                Example: Configuring Expression MIB from SNMP

                                The following example shows how to configure the Expression MIB by using the snmp mib expression command in global configuration mode: 

                                Device(config)# snmp mib expression owner pcn name exp6 
Device(config-expression)# description this expression is created for the sysLocation MIB object
Device(config-expression)# expression ($1+$2)*800/$3
Device(config-expression)# delta interval 120
Device(config-expression)# value type counter32
Device(config-expression)# enable
Device(config-expression)# object 2
Device(config-expression-object)# id ifInOctets
Device(config-expression-object)# wilcard
Device(config-expression-object)# discontinuity object sysUpTime
Device(config-expression-object)# conditional object mib-2.90.1.3.1.1.2.3.112.99.110.4.101.120.112.53 wildcard
Device(config-expression-object)# sample delta
Device(config-expression-object)# end

                                Additional References

                                Related Documents

                                Related Topic

                                Document Title

                                Cisco IOS commands

                                Cisco IOS Master Command List, All Releases

                                SNMP commands: complete command syntax, command mode, command history, defaults, usage guidelines, and examples

                                Cisco IOS SNMP Command Reference

                                Cisco implementation of RFC 1724, RIP Version 2 MIB Extensions

                                RIPv2 Monitoring with SNMP Using the RFC 1724 MIB Extensions feature module

                                DSP Operational State Notifications for notifications to be generated when a digital signaling processor (DSP) is used

                                DSP Operational State Notifications feature module

                                Standards and RFCs

                                Standard/RFC

                                Title

                                CBC-DES (DES-56) standard

                                Symmetric Encryption Protocol

                                STD: 58

                                Structure of Management Information Version 2 (SMIv2)

                                RFC 1067

                                A Simple Network Management Protocol

                                RFC 1091

                                Telnet terminal-type option

                                RFC 1098

                                Simple Network Management Protocol (SNMP)

                                RFC 1157

                                Simple Network Management Protocol (SNMP)

                                RFC 1213

                                Management Information Base for Network Management of TCP/IP-based internets:MIB-II

                                RFC 1215

                                Convention for defining traps for use with the SNMP

                                RFC 1901

                                Introduction to Community-based SNMPv2

                                RFC 1905

                                Common Management Information Services and Protocol over TCP/IP (CMOT)

                                RFC 1906

                                Telnet X Display Location Option

                                RFC 1908

                                Simple Network Management Protocol (SNMP)

                                RFC 2104

                                HMAC: Keyed-Hashing for Message Authentication

                                RFC 2206

                                RSVP Management Information Base using SMIv2

                                RFC 2213

                                Integrated Services Management Information Base using SMIv2

                                RFC 2214

                                Integrated Services Management Information Base Guaranteed Service Extensions using SMIv2

                                RFC 2271

                                An Architecture for Describing SNMP Management Frameworks

                                RFC 2570

                                Introduction to Version 3 of the Internet-standard Network Management Framework

                                RFC 2578

                                Structure of Management Information Version 2 (SMIv2)

                                RFC 2579

                                Textual Conventions for SMIv2

                                RFC 2580

                                Conformance Statements for SMIv2

                                RFC 2981

                                Event MIB

                                RFC 2982

                                Distributed Management Expression MIB

                                RFC 3413

                                SNMPv3 Applications

                                RFC 3415

                                View-based Access Control Model (VACM) for the Simple Network Management Protocol (SNMP)

                                RFC 3418

                                Management Information Base (MIB) for the Simple Network Management Protocol (SNMP)

                                MIBs

                                MIB

                                MIBs Link

                                • Circuit Interface Identification MIB

                                • Cisco SNMPv2

                                • Ethernet-like Interfaces MIB

                                • Event MIB

                                • Expression MIB Support for Delta, Wildcarding, and Aggregation

                                • Interfaces Group MIB (IF-MIB)

                                • Interfaces Group MIB Enhancements

                                • MIB Enhancements for Universal Gateways and Access Servers

                                • MSDP MIB

                                • NTP MIB

                                • Response Time Monitor MIB

                                • Virtual Switch MIB

                                To locate and download MIBs for selected platforms, releases, and feature sets, use Cisco MIB Locator found at the following URL:

                                http:/​/​www.cisco.com/​go/​mibs

                                Technical Assistance

                                Description

                                Link

                                The Cisco Support and Documentation website provides online resources to download documentation, software, and tools. Use these resources to install and configure the software and to troubleshoot and resolve technical issues with Cisco products and technologies. Access to most tools on the Cisco Support and Documentation website requires a Cisco.com user ID and password.

                                http:/​/​www.cisco.com/​cisco/​web/​support/​index.html

                                Feature Information for Event MIB and Expression MIB Enhancements

                                The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.

                                Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to . An account on Cisco.com is not required.
                                Table 1 Feature Information for Event MIB and Expression MIB Enhancements

                                Feature Name

                                Releases

                                Feature Information

                                Event MIB and Expression MIB Enhancements

                                12.2(33)SRE

                                12.2(50)SY

                                12.4(20)T

                                15.0(1)S

                                The Event MIB and Expression MIB feature introduces command line interface commands to configure the Event MIB and Expression MIB.

                                The following commands were introduced or modified: action (event), comparison, conditional object, delta (test threshold), delta interval, description (event), description (expression), description (trigger), discontinuity object (expression), enable (event), enable (expression), event owner, expression, falling (test threshold), frequency (event trigger), object (expression), object id, object list, rising (test threshold), sample (expression), snmp mib event object list, snmp mib event owner, snmp mib event trigger owner, snmp mib expression delta, snmp mib expression owner, startup (test boolean), startup (test existence), startup (test threshold), test (event trigger), type (test existence), value (test boolean), value type, and wildcard (expression).