Each managed device contains a management agent, which includes the protocol drivers as well as a database called a MIB (management information base). The MIB contains a set of variables which are appropriate to the device being managed. Some of these variables are event counters, which can be read to determine the status of the device. Other variables can be read or changed by the network manager, thus altering the configuration or operating parameters of the device. Management agents are often implemented in firmware on manageable devices, but may be loadable software for workstations or application servers.

Beyond these basic functions of viewing and controlling device variables, network management software may have additional features, such as the ability to access and control server consoles, the ability to discover and display node devices on the network, and the ability to set alarm thresholds and actions to be taken when a threshold is exceeded. Management software can be open or proprietary. Proprietary software is designed to manage the network devices and protocols for a specific vendors products, such as Digital Equipment or IBM, but now also generally includes provisions to handle open systems devices using industry standard management protocols such as SNMP.