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Objective
The aim of this tool is to monitor and listen for SNMP traps and enable rapid recovery actions depending on the traps received, thereby ensuring optimal functioning of applications or devices that use SNMP traps.
SNMP Traps are network packets containing data about a component of the system. They are generated by an SNMP agent when certain conditions are met and then sent to an SNMP Trap listener. Many applications use SNMP traps to communicate information about their state.
Method (summary)
Listening for these SNMP traps is an essential way of ensuring the proper functioning of such applications.
| • | Launch the SNMP trap listening wizard |
| • | Specify which trap to listen to by giving its Enterprise OID or trap number |
| • | Set automatic acknowledgements of the traps and alert thresholds. |
Result
Once an SNMP trap containing the right information is received, it is possible to run recovery actions to quickly take care of the problem. You can:
| • | Wait for a specific SNMP trap matching up to two "varbinds" OIDs containing specific strings |
| • | Acknowledge a previously received SNMP trap with another trap |
Create or edit a SNMP Trap listening
To create a new SNMP trap listening, right-click the Application/Container icon in the PATROL Console and select KM Commands > New > SNMP Trap listening....
SNMP Trap Listening Wizard — Welcome Page
To edit an existing SNMP Trap listening, right-click the SNMP Trap listening icon in the PATROL Console and select KM Commands > Edit.
Step 1: Identifying the agent and the traps to listen to
SNMP Trap Listening Wizard — Agent identification Page
| • | IP address: IP address of the computer or device where the SNMP agent is running and that will send the SNMP traps. You can leave this field empty to listen to SNMP traps from multiple computers or devices. |
| • | Community: Specifies the SNMP community name in which the Agent will be listening. Public is usually the default community used. |
| • | Enterprise ID: Enterprise ID of the SNMP Trap. You may use wildcards. |
| • | Trap number: Trap number contained in the SNMP Trap (optional). |
| • | OID 1 & 2: First and second attached variables OID that should be contained within the SNMP trap (optional). It is also possible to enter the text that should be found (or not) within the OID content. |
| • | Case sensitive: Indicates whether or not the search for the content that should be found within the attached variable content will be case sensitive. |
All these pieces of information define the SNMP Trap that is expected. Monitoring Studio will react to the SNMP Trap received only if this information is found within the SNMP Trap. All other SNMP Traps will be ignored.
 | If you are unsure about the characteristics of the SNMP trap you want to detect, you will need to use a SNMP MIB Browser tool to understand the exact meaning of each trap. You can also use the Monitoring Studio built-in SNMP trap listener tool to view in real time the SNMP traps and their characteristics that are received by the PATROL Agent. Right-click on the main Monitoring Studio icon > KM commands > Tools > Real-time SNMP Trap Listener. |
| The SNMP trap listening port is actually a Patrol Agent configuration variable: /snmp/trap_port=162.You can set this variable to whatever port you want Monitoring Studio to listen on. |
 | The SNMP Agent emitting the traps should be configured to send them to the PATROL Agent where Monitoring Studio is installed and running. If the SNMP agent is not properly configured, Monitoring Studio will not receive any SNMP trap. |
Step 2: Automatic acknowledgement
SNMP Trap Listening Wizard — Automatic acknowledgement Page
| • | Acknowledge alert(s) if the following SNMP Trap is received: Check the box if you wish to acknowledge an alert thanks to an SNMP trap received that matches the criteria set. |
| • | Trap number: Enter the trap number that will acknowledge the alerts triggered by the specified trap. |
| • | OID1 & 2: Definition of the attached variables OID that should be contained within the SNMP trap to acknowledge a matching trap received. |
| • | Acknowledge alert(s) if the following timeout is reached: Check the box if you wish to acknowledge a matching SNMP trap after a certain time has been reached. |
| • | Timeout value: Time, in minutes, after which the matching SNMP Trap received, will be acknowledged. This value is only applicable if you have checked the "Acknowledge alert(s) if the following timeout is reached" box. |
| • | Action to be taken when the condition above is reached: |
| ▪ | Reset the MatchingTrapCount parameter to zero, i.e. clear all previous alerts |
| ▪ | Decrease the MatchingTrapCount by one; i.e. clear the previous alert |
Step 3: Monitoring Studio settings
SNMP Trap Listening Wizard — Settings Page
| • | Object display name: Label displayed in the PATROL Console. |
| • | Object internal identifier (ID): PATROL internal identifier of this monitored object. |
What thresholds do you want to set for the newly created instance? A drop-down list allows you to select the mode of setting alert thresholds:
| • | Use default thresholds: Uses the default thresholds set by Monitoring Studio |
| • | Set custom thresholds: Allows you to customize the thresholds for all parameters of the instance |
| • | Use default thresholds and customize them: Sets the default Monitoring Studio thresholds on certain parameters (see list of parameters with default thresholds) and then allows you to customize any/all of them. This is mainly intended to help save time if you wish to customize the thresholds of just one of many parameters for the instance, and leave the default settings for the others. |
| If you select Use default thresholds and customize them; on clicking Finish, the Set Thresholds panel will appear, certain parameters for the instance may appear with an asterisk symbol - indicating that they already have thresholds. You can then customize (any/all) the thresholds of the parameters as per your specific needs. |
| • | Do not set any thresholds for now: No thresholds will be set on any parameter of the instance, and as a result no alerts will be triggered. Monitoring Studio will poll the object and return the output of the polling, but will not raise any alerts until you set thresholds. |
 | Thresholds can be set or modified at anytime by right-clicking on the instance > KM commands > Set Thresholds. |
SNMP Trap listening objects are instances of the SW_SNMP_TRAPS class.
See Also
SNMP Browser tool
SNMP Trap Listener tool
SW_SNMP_TRAPS
Although SNMP Trap listening seems to work, no trap matches my criteria
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