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The IPSentry SNMP Monitoring Add-In provides you with the ability to query SNMP values on SNMP compliant devices and generate alerts when those values are either inaccessible or outside of your specified thresholds.

From the Entry Editor, set the Type of entry to Add-In, click Select Add-In and select the SNMP Monitor and Alert add-in.
Click on the Configure Add-In button.

SNMP Monitor Configuration - General Settings

SNMP Monitoring and Alerting Add-In Configuration

After selecting to Configure Add-in from the main IPSentry Entry Editor, you will be presented with the SNMP Monitor configuration options.

Tools - Import MIB File
Provides you with the ability to import a vendor specific MIB definition file.  Objects specified in the selected MIB (and imports) will appear in the OID Tree structure for selection.  When importing MIB files, be sure to obtain and identify all required supporting MIB definitions from the vendor.

The SNMP Import will prompt you for any MIB imports if it can not locate the MIB file within it's existing cache and you will need to locate the requested MIB definition in order to successfully continue with the import process.

Tools - Test Configuration
Performs a TEST monitor using the currently defined configuration parameters.
The add-in will return a message indicating whether the current values would or would not trigger alerts based on the results.

Tools - Reset OID Cache
Selecting this option resets the Add-In Cached OID tree to the defaults as distributed with the add-in.
A reset will limit the human readable object values available for selection and may require re-importing vendor specific MIBs.

Edit - Add Filter
See: Filters / Add (button)

Edit - Modify Filter
See: Filters / Modify (button)

Edit - Remove Filter
See: Filters / Remove (button)

Edit - Get Value
Selecting this option will attempt to query the defined host and obtain the value associated with the currently selected object.

Edit - Walk MIB
Selecting this option will start a walk of the SNMP MIB on the defined host starting at the currently selected object in the OID tree.  We highly recommend performing a walk only when you have selected a tree node that will contain data associated with the values for which you are searching.  Depending on the host you are walking, selecting to walk a MIB from the iso.org.dod.internet.mgmt.mib-2 level could return thousands upon thousands of values.  Getting closer to your target definition can reduce this to just a few values.

IP Address
Enter the IP Address or DNS name of the SNMP device you wish to monitor.
Each SNMP Add-In monitoring entry in IPSentry allows for one IP device yet provides the ability to monitor many values on that device.

Port
Enter the port number on which the SNMP agent is listening. The default is 161

Timeout
Enter the timeout, in milliseconds, that the SNMP add-in should wait for a response or successful connection when the device is queried.

Retry
Enter the number of attempts that should be made to get a response from the SNMP agent.

SNMP Version
Select the SNMP version to be used when communicating with the SNMP Manager or Device.
V1 = SNMPV1, V2 = SNMPV2c, V3 = SNMPV3

V1/V2c Community
Enter the read access community name required to read values from the specified host.  The default is 'public'

Static Reply Port
By default, the SNMP Monitor opens a dynamic port to receive the UDP SNMP Response from the specified host.  In rare instances, the SNMP host may only send responses to SNMP Get requests to a specific port.  In such a case, this field allows you to specify the port on which the SNMP Add-in should listen for responses from the host.  The default value is zero (0) which designates the listening port to dynamic.

V3 - Username
Enter the username required for read access on the SNMP v3 Device.

V3 - Password / Verify
Enter the password (and verify) required for read access on the SNMP v3 Device.

V3 - Auth
Select the authentication mechanism as defined by the SNMP v3 Device

V3 - Enc Password / Verify
Enter the encryption password as defined by the SNMP v3 Device

V3 - Engine ID
If required, enter a specific engine identifier.  By default this should remain unchanged as IPSentrySNMP.

Ignore Connection Failures
When this option is checked, the add-in will NOT return an ALERT STATE back to IPSentry if no values were retrieved from the SNMP device.  Use this if you only want to be alerted when values are outside of the defined thresholds, but connectivity to that device is not required.

Return Full Results
When the add-in triggers an alert, it sends back a failure notice message to IPSentry.  This message can be used in textual alerts such as Email & Alpha Paging using the %IPS_RECV_Fnnn% keyword.   Normally, the message contains only the SNMP variables and values that triggered the failure.  When you check this option, the return message contains all variables and their values even though only one may have triggered the alert.

Test Config
Click this button to perform a test which will query the defined host for the specified filters......

OIDs (Object ID Tree)
This tab contains a list of all Objects loaded during previous MIB Definition Imports and currently contained in the MIB OID Cache.  Not all of these are available on the specified host and are specific to the SNMP device manufacturers specifications.

Use this list to traverse the available OID's.  You can right-click on an object in order to access the Edit menu options to query, walk, and add the value as a filter.

Walked (Walked Object ID Tree)
When you highlight an object in the OID Tree and hit the WALK button, the SNMP Add-in will begin issuing GET and GET NEXT requests to the SNMP device.   As the responses are returned, the Walked Tree listing will begin to be filled with objects and values available from the device.

Use the Walked Tree to see the various objects and values associated.  Especially with regards to tables and table entries. 

For example, a device such as a WAN router might have 2 or more interfaces with similar values.  Although the MIB defines an ifTable and associated objects, there would be multiple interface entries (1 and 2).  You would need to know which interface identity to use to monitor the WAN port and which identity to monitor the NET port.  Each of the interfaces will have a unique and distinct Object ID.

The Walked OID list contains all objects available for query from the device. 
Notice in the sample that we have multiple numbered entries under ifAdminStatus.
Each of these entries represent that value for the specified ifEntry in the ifTable.

In order to query a table entry, you must know the exact entry number or simply perform a walk on the table to obtain the ID.
 SNMP Mib Walk Values

You can double-click on a value to obtain the object value immediately.
SNMP Object Query

Filters [tab]

SNMP Monitoring and Alerting Add-In Configuration
This tab contains the list of SNMP query filters to be evaluating during a monitoring cycle.

Filters List
The filters list contains the list of SNMP query filters to be evaluating during a monitoring cycle.

OID
This column is the object ID to be queried on the specified host.

Name
The user defined 'display name' of the entry.  You may customize this name for use in the return results to better identify the value.  This value is also used in the graphing subsystem as a value reference.

Filter
This column contains the verbal representation of the filter you have defined on this object.

Current Value
This column contains the last value obtained after you click the "Query Values" button.

Query Values
Click this button to perform a query of all filter values and fill in the Current Value column of the filter list.

Add
Click this button to add a new object filter to the filters list.

Modify
Click this button to modify the currently selected filter.

Remove
Click this button to remove the currently selected filter from the filters list.

Object Properties

SNMP Monitoring and Alerting Add-In Configuration
This tab contains information regarding the currently selected object in the OID tree.

OID
Displays the object identifier for the currently selected object.

Name
Displays the name, as defined in the MIB Definition file, for the currently selected object

Full Path
Displays the full verbose object id of the currently selected object.

Type
Displays the object type of the currently selected object.

Description
Displays the description, as defined in the MIB definition file, for the currently selected object.

Syntax (within description)
The 'syntax' is the syntax ad defined by the MIB definition file and is for reference purposes.

Object Value

SNMP Monitoring and Alerting Add-In Configuration
This tab contains the object properties and the last obtained value of the selected object in the OID tree.

OID
Displays the object identifier for the currently selected object.

Name
Displays the name, as defined in the MIB Definition file, for the currently selected object

Full Path
Displays the full verbose object id of the currently selected object.

Type
Displays the object type of the currently selected object.

Value
Displays the value returned from a query to the defined host for the specified object.

Object Filter Details

SNMP Monitoring and Alerting Add-In Configuration

The SNMP Monitor allows many configuration options with regards to evaluating an object value.  The options available will depend on the object type being referenced as well as the comparison that you wish to make.

Calculate Rate
Enable the Calculate Rate option to have the SNMP add-in compare the most recent value with the previously obtained value and calculate the flow rate within the specified time frame.

Select the Rate Scale in units/second.

The SNMP object being queried should have a raw value of "octets" or bytes.   e.g. iso.org.dod.internet.mgmt.mib-2.interfaces.ifTable.ifEntry.ifInOctets...
The add-in will retain the previous value obtained and subtract that from the current value. 
The add-in will then calculate the number of seconds elapsed since the last value was obtained and then calculate the result as units per second.

Note that when you select "Query Object", you will be shown the raw value and not the calculated value.
The calculated value of Units/Second will only be displayed during a full "Query Values" or "Test Config".
Note also that the result will be zero if no previous value is available.
Also, if the interface is reset and the value is set to zero, the base value will be zero.

Comparison Type
The comparison options available are as follows:

For all options,  MUST or MUST NOT is specified as the evaluation basis.

Be Equal To
Select this option to compare the returned value to a single specific value that you define as the threshold.  If the selected object is non-numeric, you will be given the option to apply case sensitivity to the comparison.
e.g.  MyComputerName is not equal to MYcomputerName (case sensitive)

Be Like
For non-numeric values, you may specify simple wild cards (*,?,#) as the comparison option.
e.g. MyComp* is like MyComputer, but it is not like "This is MyComputer"
e.g. *MyComp* would match both "MyComputer" and "This is MyComputer"
e.g. ?MyComp* would not match "MyComputer" but it would match "This is MyComputer"

Contain
For non numeric values, you can specify that the returned value contain specific text.

Be Greater Than
You will be able to specify a value of which the returned value should or should be greater than.

Be Less Than
You will be able to specify a value of which the returned value should or should be less than.

Be Within Range
You will be able to specify a low and high value range within which the returned value should or should not be found.

Have Changed
The add-in will compare the last value obtained to the most current value to see if that value has changed.

Have Increased
The add-in will compare the last value obtained to the most current value to see if that value has increased.

Have Decreased
The add-in will compare the last value obtained to the most current value to see if that value has decreased.

Have Changed By
Similar to the "Have Changed" option, you have the added option to specify a value by which a change is allowed or disallowed.

Have Increased By
Similar to the "Have Increased" option, you have the added option to specify a value by which a change is allowed or disallowed.

Have Decreased By
Similar to the "Have Decreased" option, you have the added option to specify a value by which a change is allowed or disallowed.

Object Filter Samples

Evaluating Rate based values

SNMP Monitoring and Alerting Add-In Configuration
In the above example, we are evaluating the ifInOctets value of the WAN interface (inbound traffic) and have specified that the calculated flow rate should be less than .7 Mbits/s
If the calculated Mbits/s rises above .7 Mbits/s, our alerts will be triggered.

 

Evaluating Changes, Increase, Decrease (delta)

SNMP Monitoring and Alerting Add-In Configuration
You may specify Delta based changes, increases, decreases whereby you specify the amount of change that may or may not be accepted and the base-line point.

Selecting Since Last Check will compare the returned value against the value obtained during the last poll.  The value obtained will be the new base-line for the next check.

Selecting Sine Last Change Trigger will cause evaluation of the returned value against the last value that caused a trigger to occur.  The base line value will only change when that value causes a critical trigger.  Otherwise, the base-line will remain unchanged.

Evaluating Changes, Increase, Decrease
SNMP Monitoring and Alerting Add-In Configuration
You may specify general Increase, Decrease, and Change detection which will evaluate the returned result against the value returned during the last check.

Evaluating Ranges

SNMP Monitoring and Alerting Add-In Configuration
You may specify a RANGE within which the returned value must or must lie. 

Evaluating Text (contain)

SNMP Monitoring and Alerting Add-In Configuration
When evaluating an object which returns a non-numeric value, you will be able to define whether the value should CONTAIN specific text.   This option is only useful on non-numeric values such as Octet String....
 

Importing MIB Definition Files

IPSentry SNMP Query Monitoring Add-in and Mib Browser

During a MIB Definition file import, the SNMP Monitor will attempt to locate any referenced definition in the cache based on previously loaded MIBs.   If the reference can not be resolved, you will be prompted to locate the MIB definition file so that external object references can be resolved.

Before importing MIBs, you can look at the text of the MIB definition file and identify what external references are going to be required by reviewing the IMPORTS section at the top of the MIB.  This section outlines what objects, identifiers, and other references will be made to external definitions which may require an additional MIB definition file.


This window is displayed when you double-click or select to Get Value  from the OID tree.  From this window, you have the option to add this object to your filter list and begin the Filter Configuration.

 



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