Apple PowerBook Duo Dock (including Duo Dock Plus) - Manual (Page 25)

Connecting your Duo Dock to Ethernet
Before you can use your dock on a network, you must connect it to the
Ethernet network by connecting an Ethernet adapter and cable to the
Ethernet port on the dock. After connecting the dock, you must put the
PowerBook Duo in the dock and make sure your PowerBook can
communicate with the network.
With the appropriate Apple Ethernet adapter (or other compatible adapter),
you can connect your Duo Dock to an existing Ethernet network using thin
coax, 10BASE-T twisted pair, thick coax, or other standard cables. (See an
Apple-authorized dealer for more information on Apple Ethernet adapters for
your Duo Dock.)
Apple Ethernet
thin coax transceiver
Apple Ethernet
AUI adapter
Apple Ethernet
twisted-pair transceiver
19 Using Your Duo Dock on an EtherTalk Network