Monitoring Your Network - Monitoring Nodes - Using the NerveCenter Client -
Using the NerveCenter Web Client Generating Reports

Using the NerveCenter Client

The NerveCenter Client enables you to perform two types of node-related tasks. First, it enables you to view a list of alarms that can be instantiated for a node and a list of the alarms that are currently instantiated for a node. Second, the NerveCenter Client enables you to quickly query a node to determine its status.

For further information about these subjects, see the following subsections:

Viewing Related Alarms

The NerveCenter Client can provide you with lists of:

The alarms that can be instantiated for a node.
The alarms that have been instantiated for a node. For each alarm instance, NerveCenter lists an alarm name, the enabled status of the alarm, the alarm's state, the subobject the alarm is monitoring, and the time at which the alarm instance was created. This information enables you to monitor the status of a node from the Node Definition window instead of the Alarm or Aggregate Alarm Summary window.

To view the alarms related to a node:

From the Client's Admin menu, choose Node List.
The Node List window is displayed.
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.
Select the Alarms tab.
The Alarms tab is displayed.

In this example, the only alarm that has been instantiated is IfLoad. This alarm instance is monitoring interface 2 and is in the state medium, indicating that there is a moderate level of traffic on this interface.
The other alarms in the list are alarms that will be instantiated if:
- All the necessary NerveCenter objects are enabled
- The conditions that the alarms are designed to monitor actually occur
  To see the documentation for an alarm, double-click the entry for an alarm to bring up the Alarm History window; then, click the Notes button.

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:

From the Client's Admin menu, choose Node List.
The Node List window is displayed.
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.
Select the Query Node tab.
The Query Node tab is displayed.
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.
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.

Viewing Parent Node Status

NerveCenter monitors parent-child relationships and uses this information for downstream alarm suppression, suppressing alarms from any nodes that are downstream from a down router. The Parents tab of the Node Definition window displays the status that is obtained from NerveCenter's SetNodeStatus Perl subroutines.

Designing and Managing Behavior Models

Open NerveCenter: Downstream Alarm Suppression

To view the status of parent nodes:

From the Client's Admin menu, choose Node List.
The Node List window is displayed.
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.
Select the Parents tab.
The Parents tab is displayed.
Select Refresh to update parent status information displayed in the window.

Using the NerveCenter Web Client	Generating Reports
	29 July 2003