Segmentation (As opposed to Trunk and Drop) Each device should connect to a switch or hub and not a central trunk.
Media EtherNet/IP networks can include both copper pair wires and fiber optic cables. To switch between them, certain hardware requirements must be met, but the network is not limited to one or the other. There is a length limit depending on the speed you use within the network. Generally, it is good practice to limit a cable line to 100 meters. Finally, interference must be considered. It is not good practice to run media near strong electric or magnetic fields like those created by lights, motors, or arc welders.
For a more complete list of media considerations, physical requirements, or implementation specifics, read the ODVA’s “Network Infrastructure for EtherNet/IP” manual.