SNMP Traps

Devices runnining an agent send traps to the SNMP master to indicate errors, changes in status or other events. The capability to send traps is defined by the agent running on the host being monitored. Like SNMP Objects, Traps are also defined in either the public (MIB-II) or private (enterprise) MIBs for a given device. Traps are useful because they are sent when an error occurs and provide an instantaneous means of notification in real time. By utilizing this functionality, it is not necessary to poll a host at short intervals.

When an agent sends a trap, it can be identified by the SNMP master by its major and minor trap numbers and using the information in the appropriate MIB file, can be translated into a useful text message the administrator can understand. This assists pinpointing common problems with a device by having the device report exactly what failed.