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This feature module describes the addition of Event MIB support for Simple Network Management Protocol (SNMP) in Cisco IOS Release 12.1(3)T and Cisco IOS Release 12.0(12)S. It includes information on the benefits of the new feature, supported platforms, supported standards, and new Cisco IOS commands that can be used to monitor Event MIB activity.
This document includes the following sections:
The Event MIB provides the ability to monitor Management Information Base (MIB) objects on a local or remote system using SNMP and initiate simple actions whenever a trigger condition is met (for example, an SNMP trap can be generated when an object is modified). When notifications are triggered by events, the Network Management System (NMS) does not need to constantly poll managed devices to find out if something has changed.
When combined with the Expression MIB support introduced in Cisco IOS Release 12.0(5)T, Event MIB support in Cisco IOS software provides a flexible and efficient way to monitor complex conditions on network devices..
By allowing SNMP notifications to take place only when a specified condition is met, Event MIB support reduces the load on affected devices, significantly improving the scalability of network management solutions.
The Event MIB can be made to monitor any MIB object. However, the type of sampling dictates the types of objects that can be monitored.
Event MIB configuration is done with applications external to Cisco IOS software. One method for performing network monitoring of Event MIB conditions is to use a workstation to perform SNMP Gets and Sets on the SNMP agent running on the routing device. Another method is to use the functionality built in to a network management application (typically a GUI-based program running on a dedicated computer) which is compatible with Cisco IOS software.
For SNMP configuration information using Cisco IOS software, see the "Configuring SNMP Support" chapter of the Release 12.1 Cisco IOS Configuration Fundamentals Configuration Guide and the "SNMP Commands" chapter of the Release 12.1 Cisco IOS Configuration Fundamentals Command Reference.
For information on utilizing SNMP MIB features, see the appropriate documentation for your network management system.
For a complete description of the Event MIB, see the Event MIB file EVENT-MIB.my, available through Cisco Connection Online (CCO) at http://www.cisco.com/public/mibs/v2/.
For further information, see the Internet Draft document titled "Event MIB" available at http://ftp.ietf.org/internet-drafts/draft-ietf-disman-event-mib-10.txt.
The Event MIB is supported on the following platforms in Cisco IOS release 12.1(3)T:
The Event MIB is supported on the following platforms in Cisco IOS release 12.0(12)S:
Standards
No new or modiried standards are supported by this feature.
MIBs
This feature introduces the Event MIB.
The EVENT-MIB.my file can be downloaded from the Cisco MIB web site on CCO at http://www.cisco.com/public/sw-center/netmgmt/cmtk/mibs.shtml.
RFCs
At the time of the release of Cisco IOS Version 12.1(3)T (July 2000), the "Event MIB" is an "Internet Draft" and has not yet been given an RFC classification by the Internet Engineering Task Force (IETF).
Use of the Event MIB as described in this feature module assumes that you have configured SNMP on your routing devices and are using the SNMP features of an external network management tool (such as the UNIX-based SNMP ultility) or NMS (such as CiscoWorks2000).
The Event MIB allows a user or NMS to watch over specified objects and set event triggers based on existence, threshold and boolean tests. An event occurs when a trigger is fired; this means that a specified test on an object returns a value of "true". To create a trigger, a user or NMS configures a trigger entry in the mteTriggerTable of the Event MIB. This trigger entry specifies the object identifier (OID) of the object to be watched. For each trigger entry type (existence, theshold, and boolean triggers), corresponding tables (existence, threshold, and boolean tables) are populated with the information required for carrying out the test. The MIB can be configured so that when triggers are activated (fired), either an SNMP Set is performed, a notification is sent out to the interested host, or both.
Wildcarding is a powerful functionality provided by the Event MIB which allows you to monitor multiple instances of an object. You can specify a single OID for monitoring, or use wildcarding to specify a group of OIDs.
There are nine tables in the Event MIB. They are:
The trigger entry is set in the trigger table. Each trigger is configured to watch a single object or a group of objects specified by a wildcard (*). The object-type can be any one of the types given below:
The Event MIB process checks the state of this watched object at predefined intervals. The interval can be configured through the mteTriggerFrequency object. The type of sampling that can be done on an object is of two types:
The test that can be done on the watched object is one or a combination of the following:
For each of the above tests the mteTrigger<Exist/Bool/Threshold>Startup can be true or false to indicate whether the trigger should be fired as soon as it is activated or not.
The Existence Test can be one or a combination of the following:
The Boolean test can be one of the following:
The Threshold test can be one of the following:
The Event Table has an entry for what type of action to take for the event. This could one or both of the following:
The Notification Table contains a list of objects corresponding to an entry in the Event Table. This list of objects is added to the notification sent out when the trigger fires.
The Set Table may contain an object for each event defined in the Event Table. When the trigger fires this object is set to the value specified in the table.
There are no Cisco IOS software configuration tasks associated with the Event MIB. The "Configuration Examples" section gives a sample configuration session using a network management application on an external device. See the "Related Documents" section for information on configuring SNMP on your Cisco routing device.
Use the following commands to monitor Event MIB activity from the Cisco IOS command-line interface:
| Command | Purpose |
|---|---|
Router#debug management event | Prints messages to the screen whenever a the Event MIB evaluates a specified trigger. These messages are are given in real-time, and are intended to be used by technical support engineers for troubleshooting purposes. |
Router#show management event | Displays the SNMP Event values that have been configured on your routing device through the use of the Event MIB. |
All configuration of Event MIB functionality must be performed though applications using SNMP. The following example 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 that these commands are not Cisco IOS CLI commands. This example assumes that SNMP has been configured on your routing device.
In this example, 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 four parts to the following example:
| Command | Purpose | |
|---|---|---|
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 sixty 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. |
| Command | Purpose | |
|---|---|---|
Step 1 | setany -v2c $ADDRESS private mteEventEntryStatus.4.106.111.104.110.101.118.101.110.11 6 -i 5 | Create a row in the Event Table. The mteOwner here is again "john" and mteEventName is "event". 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.4.106.111.104.110.101.118.101.110.11 6 -i 1 | Makes the EventRow active. |
| Command | Purpose | |
|---|---|---|
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 "john" 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 that is to be performed. |
| Command | Purpose | |
|---|---|---|
Step 1 | setany -v2c $ADDRESS private mteTriggerEntryStatus.4.106.111.104.110.1 -i 1 | Makes the trigger active. |
To confirm 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.
This section documents new commands. All other Cisco IOS commands used with this feature are documented in the Release 12.1 Cisco IOS Configuration Fundamentals Command Reference publication. The following commands are documented:
To display the SNMP Event values that have been configured on your routing device through the use of the Event MIB, use the show management event command in privileged EXEC mode.
show management eventSyntax Description
This command has no arguments or keywords.
Defaults
No default behavior or values.
Command Modes
Privileged EXEC
Command History
12.1(3)T This command was introduced.
Release
Modification
Usage Guidelines
For information on Event MIB functionality, read the EVENT-MIB.my file on your routing device, or download the file from the Cisco MIB website on CCO at http://www.cisco.com/public/sw-center/netmgmt/cmtk/mibs.shtml .
Examples
The following example shows sample output of the show management event command:
Router# show management event
Mgmt Triggers:
(1): Owner: aseem
(1): 01, Comment: TestEvent, Sample: Abs, Freq: 120
Test: Existence Threshold Boolean
ObjectOwner: aseem, Object: sethi
OID: ifEntry.10.3, Enabled 1, Row Status 1
Existence Entry: , Absent, Changed
StartUp: Present, Absent
ObjOwn: , Obj: , EveOwn: aseem, Eve: 09
Boolean Entry:
Value: 10, Cmp: 1, Start: 1
ObjOwn: , Obj: , EveOwn: aseem, Eve: 09
Threshold Entry:
Rising: 50000, Falling: 20000
ObjOwn: ase, Obj: 01 RisEveOwn: ase, RisEve: 09 , FallEveOwn: ase, FallEve: 09
Delta Value Table:
(0): Thresh: Rising, Exis: 1, Read: 0, OID: ifEntry.10.3 , val: 69356097
Mgmt Events:
(1): Owner: aseem
(1)Name: 09 , Comment: , Action: Set, Notify, Enabled: 1 Status: 1
Notification Entry:
ObjOwn: , Obj: , OID: ifEntry.10.1
Set:
OID: ciscoSyslogMIB.1.2.1.0, SetValue: 199, Wildcard: 2 TAG: , ContextName:
Object Table:
(1): Owner: aseem
(1)Name: sethi, Index: 1, OID: ifEntry.10.1, Wild: 1, Status: 1
To monitor the activities of the Event MIB in real time on your routing device, use the debug management event command in privileged EXEC mode. To stop output of debug messages to your screen, use the no form of this command.
debug management eventSyntax Description
This command has no arguments or keywords.
Defaults
Debugging output is disabled by default.
Command Modes
Privileged EXEC
Command History
12.1(3)T This command was introduced.
Release
Modification
Usage Guidelines
The debug management event command prints messages to the screen whenever the Event MIB evaluates a specified trigger. These messages are are given in real-time, and are intendended to be used by technical support engineers for troubleshooting purposes.
Examples
The following example shows sample output for this command:
Router# debug management event Event Process Bool: Owner aseem, Trigger 01 Event Bool process: invoke event Event Bool process: no wildcarding Event: OID ifEntry.10.3 Event getValue abs: 69847284 Event Bool process: Trigger Fired ! mteSetNotifyObjects: Event execOnFiring: sending notification Event: OID ifEntry.10.1 Event add_objects: Owner , Trigger Event add_objects: Owner aseem, Trigger sethi Event Found Owner: aseem Event Found Name: sethi Event: OID ifEntry.10.1 Event: sending trap with 7 OIDs Event: OID mteHotTrigger.0 Event: OID mteHotTargetName.0 Event: OID mteHotContextName.0 Event: OID ifEntry.10.3 Event: OID mteHotValue.0 Event: OID ifEntry.10.1 Event: OID ifEntry.10.1 Event mteDoSets: setting oid Event mteDoSets: non-wildcarded oid Event: OID ciscoSyslogMIB.1.2.1.0 Event Thresh Process: Owner aseem, Trigger 01 Event Thresh process: invoke rising event Event Thresh process: invoke falling event Event Thresh process: no wildcarding Event: OID ifEntry.10.3 Event getValue abs: 69847284 Event Existence Process: Owner aseem, Trigger 01 Event Exist process: invoke event Event Exist process: no wildcarding Event: OID ifEntry.10.3 Event getValue abs: 69847284 Event Check ExistTrigger for Absent Event Check ExistTrigger for Changed Router# no debug management event
IETF—Internet Engineering Task Force. The IETF is the body (supervised by the Internet Architecture Board) that defines Internet operating standards such as SNMP MIBs, and publishes RFCs for use by the Internet community. The IETF's web site address is http://www.ietf.org.
MIB---Management Information Base. The MIBs referred to in this document are MIB modules. These modules contain definitions of management information for use by SNMP network management systems.
OID—Object Identifier. The values for OIDs are defined in specific MIB modules.
NMS—Network Management System. An application or suite of applications designed to monitor networks using SNMP. CiscoView is one example of an NMS.
SNMP—Simple Network Management Protocol. Network management protocol used almost exclusively in TCP/IP networks. SNMP provides a means to monitor and control network devices, and to manage configurations, statistics collection, performance, and security.
Posted: Tue Sep 19 17:40:48 PDT 2000
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