Switch unit, ethernet network, and method for activating components in an ethernet network

An Ethernet network comprising at least one switch unit that is connected to control units and/or additional switch units, the at least one switch unit comprising:

• a switch having a microprocessor, the switch having at least three ports that are connected to inputs and outputs of the at least one switch unit;
• a signal detector and generator adapted to detect and initiate a bus activity, the signal detector and generator being arranged between the at least three ports and the inputs and outputs of the at least one switch unit;
• and
• a memory, wherein, for each input and output, an allocation rule to the other inputs and outputs of the at least one switch unit is stored in the memory,
• wherein the at least one switch unit is configured such that, when a bus activity is detected at the signal detector and generator, assigned inputs and outputs of an input and output of the signal detector and generator are read out from the memory so that the signal detector and generator generates a bus activity at the assigned inputs and outputs.