Other Network Considerations
Topology covers both physical and network considerations, but some requirements cover only the network. EtherNet/IP networks are full-duplex networks. As mentioned before, that allows for communication in both directions simultaneously. This is not a consideration unless you decide to use hubs, which can limit that full-duplex ability through their half-duplex operation.
You will need to decide, though, whether your network is isolated or integrated. An isolated network does not connect to any other outside network. An integrated network does connect outside the network, most commonly to the internet. Integrated networks have unique security concerns.