Midi Ports

Does anybody know how to assign physical midi ports so that the midi track only listens to a particular midi port and channel. Logic by default sums all incoming midi signals and all ports and channels and plays them on the out port assigned to the track when selected. Very annoying. I've seen people do this somehow in the environment of logic but I've never found a comprehensive explanation or tutorial.

If audio was routed this way in logic every time you select a track all incoming audio on any audio interface port would show up on the currently selected track. Why?

Really, all that I'm trying to do is what every other daw that I've used does. For instance Ableton Live midi tracks only receive midi signal on the midi port and channel assigned to that track.