Examples of Count-Based Threshold Monitoring

You want to monitor the connections between two sites to verify that your service provider is meeting their guaranteed throughput volume. You pay a fixed cost for a specific bandwidth over this WAN interface.

• Monitor for under-utilization which wastes money (less than 10%).

  Tip If you do not care about under-utilization, set Low Value and Low Value Rearm to 0% as shown in Example 2. The Low Value threshold is then disabled because it cannot be crossed.

• Monitor for over-utilization (greater than 80%), which might result in performance bottlenecks or service provider surcharges.

Note Sometimes an Interface's MIB-II ifspeed value is not reported accurately.

This might result in threshold calculations outside the 0.00 - 100.00 range. If this happens, the Interface threshold State set to "Unavailable." To correct the problem:

1. Access the Inventory workspace
2. Open Interface view.
3. Open the form for the Interface that is reporting a threshold state of "Unavailable."
4. Navigate to the General tab.
5. Enter a valid entry in Input Speed or Output Speed (this overrides the value returned by the device's SNMP agent so that NNMi can accurately calculate utilization thresholds).

You want to monitor an important Ethernet interface and be notified if it is getting overloaded.

An Ethernet interface configured for full-duplex operation has an acceptable operating range of 0-60%. When average utilization is greater than 60%, you want NNM to generate a High Threshold incident.

You want to monitor an important Ethernet interface and be notified if it is getting overloaded or if no data has passed through the interface during the polling interval. This might indicate a problem with the interface or its connection. If a formerly connected interface is Administratively Down, NNMi honors that and does not generate a fault condition.

This example monitors for the following:

• When the average utilization is greater than 60%

• When zero data is passing through the interface

  Tip The Low Value of 0.000000000000001 used in this example because it is the smallest value greater than zero available in NNMi. When you configure a Threshold, to use this value, simply type 1E-15 and press Enter. NNMi converts that Scientific Notation to the text string 0.000000000000001 (with 1 entered in the 15th position after the decimal).

You want to know any time an interface is dropping data. The acceptable limit for interface discards is 10%. A High Threshold situation occurs when the discard rate exceeds 10% and returns to Nominal when the discard rate drops below 5%.

You want to know if packet errors occur. The acceptable limit for packet errors is 2%. A High Threshold situation occurs when the error rate exceeds 2% and returns to normal when the error rate drops below 1%.