Simple Network Management Protocol The SNMP sample has two parts: SNMPUTIL and TESTDLL. The SNMPUTIL sample demonstrates how to use the SNMP API to build SNMP manager applications on Windows NT. This is a command-line utility that lets you retrieve information from any SNMP agent in your network. The TESTDLL sample demonstrates how to build an extension agent DLL that works with the extendible SNMP agent. This DLL implements the toaster MIB and shows how new MIBs can be added to the agent through a DLL.