The invention relates to a method for operating an Ethernet-capable field-bus device that can be connected to an arbitrary Ethernet-based communications unit by means of which data is transmitted using a predetermined communications protocol stack. For this purpose, a network management channel is initially established between the Ethernet-capable field-bus device (50) and a management device (30) connected to the communications network (20) using an Ethernet-based network management protocol that is installed both in the field-bus device (50) and also in the management device (30). The communications protocol stack installed in the management device (20) is then transmitted using the predetermined network management protocol from the management device (30) to the Ethernet-capable field-bus device (50), where it is stored. In this way, it is guaranteed that useful data can be transmitted using the communications protocol stack from and to the field-bus device (50) via the Ethernet-based communications network (20).