Monitoring Your Network - Monitoring Nodes - Using the NerveCenter Client - Querying Nodes -
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Querying Nodes

In addition to listing a node's current alarm instances, the NerveCenter Client can query a node to determine whether the node is up and whether its SNMP agent is up -- without using a behavior model. To determine whether a node is up or down, you send an ICMP ping to the node, and to determine the status of a node's SNMP agent, you send an SNMP GetRequest to the node asking for information about the system object.

 
  To query a node:

1. From the Client's Admin menu, choose Node List.

   The Node List window is displayed.

   Node List Window

   

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2. Double-click the name or IP address of the node in which you're interested.

   The Node Definition window is displayed and presents the definition of the node you selected.

   Node Definition Window

   

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3. Select the Query Node tab.

   The Query Node page is displayed.

   Query Node Page

   

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4. If the node you're querying is multihomed, select the IP address you want to use for the query from the IP Address drop-down list box.
5. Select the Ping or Get button.

   If you select the Ping button, NerveCenter pings the node, and the node's response is displayed in the Ping Result field. If there is no response, the node is unreachable.

   If you select the Get button, NerveCenter sends to the node an SNMP GetRequest asking for the values of the following MIB attributes: sysDescr, sysObjectID, and sysUpTime. If the node replies with a GetResponse message that contains the values of these attributes, NerveCenter displays the values in the System Description, System Object ID, and System Up Time fields. If the node does not respond, you can infer that the node's SNMP agent is down or that the node is unreachable.

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   Note    NerveCenter must know the node's SNMP version before it can perform a GetRequest message.

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