Designing and Managing Behavior Models - Configuring SNMP Settings for Nodes - Classifying the SNMP Version Configured on Nodes - How NerveCenter Classifies a Node's SNMP Version -
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How NerveCenter Classifies a Node's SNMP Version

There are two main ways that NerveCenter classifies nodes:

• Manually -- You can issue a classify command in NerveCenter Client to classify one, several, or all nodes in the database.
• Automatically -- NerveCenter can be configured to classify nodes when they are added to its database (discovered from a trap, added from a platform such as OpenView Network Node Manager, or imported from another NerveCenter).

For a detailed study of classification, refer to the white paper "OPEN NerveCenter: Node Classification," which ships with the NerveCenter online guides. Following is a summary of classification.

Each time NerveCenter attempts to classify a node, NerveCenter sends a series of classification requests (GetRequest messages) to the node. NerveCenter classifies the node based on the responses to these requests. Each request corresponds to an SNMP version -- either v1, v2c, or v3.

While classifying a node, NerveCenter attempts to detect the maximum supported version on the agent up to a maximum specified version, which you can configure in NerveCenter Administrator. So, for example, if you set a maximum classification version of v2c, NerveCenter never attempts to classify nodes any higher than v2c. (However, you can manually specify any version for a node and then test communication with the agent using that version.)

Based on the response to its messages, NerveCenter changes its SNMP version setting for the node.

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Caution    Note the following about node classification:

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• When NerveCenter attempts to classify a node, any existing version information for the node is lost during classification. For example, if the node was previously identified as SNMP v3 and is now changed (to v1, v2c, or Unknown), then the v3 related security information for the node is lost.
• If NerveCenter fails to classify the node, then the version of the node is set to "Unknown." NerveCenter cannot poll a node with an unknown version.
• A node must have correct version information, either supplied manually by the user or obtained via classification, before NerveCenter can poll the node or process a trap from the node.