Bathroom fixtures backing up into basement floor drain

You have a blockage downstream from the drain. Are you on city sewer or a septic tank? To check if the clog's in the sewer line from the house open up the house cleanout and flush a toilet. If the cleanout backs up then the clog's in the sewer line. If it backs up out of the floor drain the clog's between the floor drain and the cleanout. If the floor drain has a cleanout plug located under the strainer you can snake from there. Good luck, Tom