Designing and Managing Behavior Models - NerveCenter Support for SNMP v3 - Using the SNMP Test Version Poll -
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Using the SNMP Test Version Poll

When configuring an SNMP agent or if you encounter problems polling a node, you can test whether NerveCenter can communicate with the agent. NerveCenter provides an SNMP test poll that verifies communication with the node using the SNMP version specified for the node. If the agent is configured for SNMP v3, this poll helps you determine whether the agent is correctly configured for communication with NerveCenter.

If the poll fails to establish a connection for the specified SNMP version, a TestVersionFail error is displayed for the node, and polling will not happen for this node.

Testing SNMP v1 and v2c Agents

To test the agent on a node configured in NerveCenter with SNMP version 1 or 2c, the Test Version poll sends the agent an SNMP GetRequest for the system description. This operation is similar to the GetRequest issued by clicking the Get button on the Query Node tab of a node's definition window.

Testing SNMP v3 Agents

To test the agent on a node configured in NerveCenter with SNMP v3, the Test Version poll issues GetRequest messages for the following:

• Engine ID for a node
• Boots/timeticks if the security level on the node is either AuthNoPriv or AuthPriv
• SysObjectID for the node

To establish communication, NerveCenter sends a GetRequest for the node's sysobjectID. Before sending this GetRequest, however, NerveCenter first requires engine information such as engineID, engine boots, and time ticks. If this information is not known to NerveCenter, NerveCenter must send a request to the agent.

NerveCenter must obtain engine information in the following cases:

• When the SNMPv3 node has an 'v3InitFail' error status. This status indicates that the engineID for that node is not available to NerveCenter.
• NerveCenter first obtains the engine ID. Then, if the security level for the node is other than NoAuthNoPriv, NerveCenter obtains the boots and time ticks.
• When the SNMPv3 node has an error status of 'TimeSyncFail.' This status indicates that the engine boots and time ticks for that node are not available to NerveCenter.
• When someone has changed the Authentication and Privacy passwords in NerveCenter Administrator but did not update the passwords on the SNMP v3 agent.

  You must change the passwords on the agent and run the V3TestPoll to restore proper communication.

After obtaining the engine information, NerveCenter can send the SysObjectID request.

How To Use the Test Version Poll

Follow the steps below to verify communication with a node using the Test Version poll.

 
  To use the SNMP Test Version poll:

1. From the client's Admin menu, select Node List.

   The Node List window is displayed.

   Node List Window

   

   Click the thumbnail above to view full-sized image.

2. Right-click one or more nodes you want to test, then select Test Version.

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   Tip    You can also issue this poll for a particular node by selecting the node in the list, clicking the Open button, and selecting Test Version in the SNMP tab.

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The Status Bar indicates the status of the test. If the test fails to establish a connection for the specified SNMP version, a TestVersionFail error is displayed for the node .