v. In ice hockey, it means to barely miss a goal when a shot eludes the goaltender, yet deflects back into play after hitting either the left or right goalpost. A hard rubber puck shot at high velocity makes a "ringing" sound, much like that of a bell, when it hits the metal goalpost, thus "ring(ing) the post." You can also "ring the crossbar" if a rising shot hits the top bar connecting the goalposts. The goaltender is considered very lucky if he is bailed out by such an event.
Wisconsin would have beat Minnesota by an even greater margin if they didn't ring the post five times. Man their goalie is a great big sieve.