The USB cable must be used to change the box to either a fixed internal
IP address for your subnet, or to DHCP to get an address from your
router automatically.
After you change it, you then must put the ethernet cable between
the box and your network and enter the internal IP address of the box.
If DHCP, you may need to read this address in the DHCP table in
your router, unless you have few devices connected and can guess it
(e.g. 192.168.1.10, 192.168.1.11, etc.)
It will not work unless you change the IP address or to DHCP first, since
the default IP address will not work in your network (unless you have subnet
192.168.0.xx), nor will it work when you directly connect the box to your PC.
Note to Mike: there seem to be a lot of standard networking questions
that pop-up, it would make a lot of sense to add a network FAQ to the
manual. Your setup section does not appear to be enough.
73,
Mitch DJ0QN / K7DX