Where is the drain pipe clogged
	
	
		The drain outside my basement door overflows and into my basement.  It is nasty and smells of sewer gas.  I have tried plunging, water pressure but nothing worked.  I have used a plumber's plunger at the sewer drain that is outside my yard but it did nothing.  It was dry.  The cleanout pipe was also checked and was dry.  I did notice that while plunging, the water in the basement water started bubbling.  When using the water pressure, the dirty water started coming up through the same toilet.  I never use this toilet, so I wouldn't think it would be clogged.  When I use my washer, the released water comes up through this drain.  The residue around the drain indicates matter from the third floor bathroom, which is always used.  Where is the clog, between the drain and the sewer or between the basement toilet and the outside drain?  Will snaking the drain work or should I snake the basement toilet?