For me, too difficult to understand what you wrote.
So I just made a very simple configuration without internet.
My MED500X2 is now connected with a LAN cable on a simple switch that doesn't need to be configured. On that switch are also two PC's connected with a straight LAN cable, both W7, automatic assign of IP and DNS. Both PC's are accessible for everyone, so I can read/write on all drives.
On both PC's under the Network icon, I also see MEDE8ER. Clicking on MEDE8ER hoping to explore the connected hard drive, there is a popup saying: Windows cannot access \\MEDE8ER - Check the spelling of the name, there might be a problem with your network bla bla bla. error code 0x80070035: the network path was not found.
So, what can I do? I think I have to enable SAMBA on the MED500X2 but where is that menu?