I have an old Seagate Central external hard-drive which has a USB-A and Ethernet port. It's meant to be connected to a router and accessed remotely; with the USB-A port used for chaining an additional drive.
I don't have access to connect the drive to my router though and I don't have a USB-A to USB-A cable at the moment to try that. I do have an Ethernet to Thunderbolt adapter so I've tried running an ethernet cable directly to my computer from the drive. In the network settings I activated the port and it immediately self-assigned itself an IP.
It showed up in the Finder sidebar but any attempt to open it in Finder fails.
I'm thinking that perhaps the port configuration is not correct or I need to be using a crossover-cable (I have some spare connectors I can swap out and make it a cross-over cable but not gonna do it unless I'm sure that's the problem).