HP Network Direr Software Products manual Configurable Poll Rates for Active Monitoring

Key Concepts 685

Configurable Poll Rates for Active Monitoring

When you are monitoring a device using an active monitoring technique (i.e. either full or response monitoring mode), 3Com Network Director polls the device on a regular basis with requests for device state information. The more frequently 3Com Network Director polls the device, the more management traffic it will generate to that device and, assuming the device is responding to request, the more traffic the device will generate in response.

If an actively monitored device is a remote device then the more frequently that device is polled, the more traffic will be generated on the WAN links on the route to that site as a result of the monitoring. If a large number of remote devices are being monitored, particularly if they are being monitored in full monitoring mode, then frequent polling can generate a large amount of traffic over the WAN links. This may result in higher latency on these links, and may even lead to the links becoming oversubscribed.

To avoid this situation, 3Com Network Director allows you to control the rate at which actively monitored devices are polled. By decreasing the poll rate you can reduce the amount of traffic generated by active monitoring.

See “Monitoring Techniques” on page 276 for more details of active monitoring and “Monitoring Mode” on page 296 for more details of full and response monitoring modes.

Configurable Monitoring Modes

3Com Network Director has different monitoring modes that it can use to monitor the devices in your network. These monitoring modes vary in the level of detail they can provide you about the state of the devices in your network, and also vary in the level of traffic they generate on your network.

When monitoring a single site network the level of traffic generated by the monitoring process is not normally an issue. However, when monitoring a multi-site network large amounts of monitoring traffic to and from remote sites can increase the latency of WAN links, possibly even causing them to become oversubscribed.