To effectively teach your puppy to leave the older dog alone you need to closely supervise and control their interactions. Your puppy is just being a puppy, so don't be mad at him, instead teach him what is and is not okay...and, again, to do that control the interactions between these two dog ALWAYS (for now). When they are allowed to interact, be very stern and direct at telling the puppy to stop, and ALWAYS ALWAYS ALWAYS enforce it. Then immediately change your demeanor and give the puppy something really fun and engaging to do - play with you, aniimate a toy, run squeal, whatever it takes to completely change his mindset! Boom, he's completely forgotten the negative and is now happy. Do this consistently and he'll catch on, but if you let it slide even 1 time in twenty, it'll take months longer for him to learn the concept.
It's not the size of the dog in the fight, it's the size of the fight in the dog. Mark Twain