Monitoring Your Network - Monitoring Alarms - Viewing an Alarm Instance's History - Using the NerveCenter Client -
Using the NerveCenter Web Client      Reading Logged Data

Using the NerveCenter Client

This section explains how to view the history of an alarm instance using the NerveCenter Client. To view this information, you bring up the Client's Alarm History window.

 
  To open the Alarm History window:

  From the Alarm or Aggregate Alarm Summary window, double-click an alarm instance.

The Alarm History window is displayed.

The top pane in the Alarm History window displays the state diagram for the relevant alarm, and the list at the bottom of the window displays the transitions that have led to the alarm instance's current state. The data displayed for each transition is similar to that displayed for an alarm instance in the Alarm or Aggregate Alarm Summary window. The only new columns are From State, To State, and #. These columns hold the state of the alarm instance before the transition, the state of the instance after the transition, and the number of the transition (first, second, and so forth).

The preceding figure shows the history of an instance of the alarm IfErrorStatus, which monitors the percentage of error packets on an interface. As you can see, the instance first transitioned from low to high, and since then has bounced back and forth between the high and medium states. The times associated with the transitions (you can't see all of them) indicate that the instance has been in the high state most of the time.

There are several actions that you can take from the Alarm History window:

• If you click the first transition in the alarm-history list, the corresponding transition in the state diagram is highlighted.

  

  By selecting the transitions in order -- from first to last -- you can watch the history of the alarm instance in the state-diagram pane.

• When you select a transition from the transition list, the Node button and typically either the Poll, Mask, or Alarm button are enabled. Selecting an enabled button opens a definition window that presents a definition of one of the following objects:
  • The node that the alarm instance is monitoring.
  • The poll that generated the trigger that caused the transition.
  • The trap mask that generated the trigger that caused the transition.
  • The alarm that generated the trigger that caused the transition.
• If the Refresh button becomes enabled while you're viewing an alarm instance's history, the alarm instance has undergone a transition while you've had the Alarm History window open. Select the Refresh button, and NerveCenter will update the information about this latest transition to the transition list.