Modify System settings
System settings can specify how your data is stored, how often data is collapsed, how often objects are polled and rediscovered, how often statistics are collected from objects, the behavior of charts, the timeout and retry intervals for ICMP and SNMP communications, and the appearance of the tree view.
- Click File > Network Performance Monitor Settings.
- Specify the information on the Database tab:
- Nightly database maintenance runs at the specified time. Maintenance uses the values specified in Statistics Summarization to compact and delete data.
- Statistics summarization provides four customizable retention periods:
- Raw data retention
- Hourly data retention
- Daily data retention
- Event retention
Polling determines availability, status, network latency, and packet loss, and is normally done more frequently than statistics collection. Intervals apply to all objects added after your changes. If you want to overwrite the current polling intervals for your nodes, click Apply these settings to All.
Rediscovery validates the identity of monitored nodes, interfaces, and volumes and automatically adjusts for most changes in this information.
Statistics collection retrieves data from your device, interface traffic and errors, volume, and CPU usage. To overwrite the current statistics collection intervals for your nodes, click Apply these settings to All.
Statistics represent summaries, peaks, and averages collected over a period of time. Statistics represent not only the activity occurring at the time of the collection, but are calculated values summarizing total activity since the last collection.
- Specify whether or not to print charts in color or monochrome using differentiating symbols.
- Specify the default font size.
- Specify whether or not to automatically refresh charts.
The ICMP Timeout is the maximum amount of time (in milliseconds) Network Performance Monitor waits for a response from an IP address. Adjust this value to the minimum practical value possible to maximize performance. A good starting point is twice the maximum PING time across your network. A few days or weeks of observing your network response times will give you a good idea of what a practical minimum should be.
If no response is received, NPM changes the status of the node to a warning state. If the device remains unresponsive during the node warning interval, the node status changes to down. For more information about node warning intervals, see Modify Advanced settings
You can edit ICMP packet content to make sources identifiable or to adjust the size. The data payload size can vary from zero (0) to 200 bytes. Some network devices consider ICMP packets with data in the payload suspicious. Try adjusting the packet size to be less than 10 bytes or remove the data from the payload of the packet.
When adjusting ICMP payload data, a byte counter is provided above the Data Portion text box.
The SNMP Timeout setting determines the number of milliseconds the Network Performance Monitor application waits for a reply before assuming the packet is lost and trying again. This setting should normally be twice the maximum PING time to any device you are monitoring. After observing the unique behavior of your network, you can adjust these values to the lowest time possible to assure responsiveness from an active device.