fallingAlarm

RMON-MIB::fallingAlarm #

The SNMP trap that is generated when an alarm entry crosses its falling threshold and generates an event that is configured for sending SNMP traps.

Variables #

  • alarmIndex
  • alarmVariable
  • alarmSampleType
  • alarmValue
  • alarmFallingThreshold

Definitions #

alarmIndex
An index that uniquely identifies an entry in the alarm table. Each such entry defines a diagnostic sample at a particular interval for an object on the device.
alarmVariable
The object identifier of the particular variable to be sampled. Only variables that resolve to an ASN.1 primitive type of INTEGER (INTEGER, Integer32, Counter32, Counter64, Gauge, or TimeTicks) may be sampled. Because SNMP access control is articulated entirely in terms of the contents of MIB views, no access control mechanism exists that can restrict the value of this object to identify only those objects that exist in a particular MIB view. Because there is thus no acceptable means of restricting the read access that could be obtained through the alarm mechanism, the probe must only grant write access to this object in those views that have read access to all objects on the probe. During a set operation, if the supplied variable name is not available in the selected MIB view, a badValue error must be returned. If at any time the variable name of an established alarmEntry is no longer available in the selected MIB view, the probe must change the status of this alarmEntry to invalid(4). This object may not be modified if the associated alarmStatus object is equal to valid(1).
alarmSampleType
The method of sampling the selected variable and calculating the value to be compared against the thresholds. If the value of this object is absoluteValue(1), the value of the selected variable will be compared directly with the thresholds at the end of the sampling interval. If the value of this object is deltaValue(2), the value of the selected variable at the last sample will be subtracted from the current value, and the difference compared with the thresholds. This object may not be modified if the associated alarmStatus object is equal to valid(1).
alarmValue
The value of the statistic during the last sampling period. For example, if the sample type is deltaValue, this value will be the difference between the samples at the beginning and end of the period. If the sample type is absoluteValue, this value will be the sampled value at the end of the period. This is the value that is compared with the rising and falling thresholds. The value during the current sampling period is not made available until the period is completed and will remain available until the next period completes.
alarmFallingThreshold
A threshold for the sampled statistic. When the current sampled value is less than or equal to this threshold, and the value at the last sampling interval was greater than this threshold, a single event will be generated. A single event will also be generated if the first sample after this entry becomes valid is less than or equal to this threshold and the associated alarmStartupAlarm is equal to fallingAlarm(2) or risingOrFallingAlarm(3). After a falling event is generated, another such event will not be generated until the sampled value rises above this threshold and reaches the alarmRisingThreshold. This object may not be modified if the associated alarmStatus object is equal to valid(1).

Meaning #

The RMON-MIB::fallingAlarm SNMP trap is generated when an alarm entry crosses its falling threshold and generates an event that is configured for sending SNMP traps. This trap indicates that a specific variable has fallen below a predetermined threshold, triggering an alarm event.

Impact #

The impact of this trap depends on the specific alarm configuration and the variable being monitored. However, in general, it may indicate a potential issue or anomaly in the system or network being monitored. The alarm event may trigger notifications, automated actions, or manual interventions to investigate and resolve the issue.

Diagnosis #

To diagnose the cause of this trap, follow these steps:

  1. Identify the alarmIndex, which uniquely identifies the alarm entry.
  2. Determine the alarmVariable, which is the object identifier of the variable being monitored.
  3. Check the alarmSampleType to understand how the variable is being sampled (absoluteValue or deltaValue).
  4. Review the alarmValue to see the current sampled value that triggered the falling alarm.
  5. Verify the alarmFallingThreshold to ensure it is set correctly.
  6. Check the system or network being monitored to identify the root cause of the alarm event.
  7. Analyze the alarm history to determine if this is a one-time event or a recurring issue.

Mitigation #

To mitigate the issue, follow these steps:

  1. Investigate and resolve the underlying cause of the alarm event.
  2. Adjust the alarmFallingThreshold if necessary to reduce false positives or improve sensitivity.
  3. Verify that the alarmVariable is correct and that the sampling method (alarmSampleType) is appropriate for the monitored variable.
  4. Consider implementing automatic actions or scripts to respond to falling alarm events, such as sending notifications or executing remediation scripts.
  5. Review and update the alarm configuration as needed to ensure it is aligned with the desired monitoring and notification policies.
Edit this page