Weird question, I know. My apartment comes with a modern/router combo that, for whatever reason, does not have an Ethernet port. So a friend advised me to purchase a modem, then connect it via coax cable to my apartment’s modem/router, then connect that to my PC via cat5. I did so, but the Ethernet connection on my PC shows no Internet. Is this possible to set up? Is there a software related step I’m missing to complete the connections?