Just had this issue myself for the last week, the wife finally annoyed me so I read everyone's different solutions and fixes but resetting the router didn't seem like a real fix to me so I went through all my settings and changed one item on my router, I enabled Jumbo Frames and bingo, started working. Router is Asus RT-N66U setting was under Advanced Settings > LAN > Switch Control. Obviously Jumbo Frames setting will not be in the same location on a different router, look over all your menus. Hopes this helps someone else.