A method for validating an Ethernet configuration of an automation system including several industrial devices, the method includes obtaining a device identifier for each of the industrial devices and indications of device ports and of device port connections. The method further includes obtaining device Ethernet parameters and instantiating a system object model of the Ethernet configuration of the automation system based on the device identifiers, the device ports and device port connections and the Ethernet parameters. The system object model allows applying predefined rules for generating a graph model representative of the Ethernet configuration. To the generated graph model cycle detection as known from graph theory may be applied by means of depth-first search. Based on the outcome of the cycle detection a validation result may be indicated. A generic Ethernet object model and a topology manager also are disclosed.