This is a common scenario. Older dogs often have trouble tolerating high energy pups. And it’s really not fair to expose an older dog to constant jumping, romping, and the general disorder that surrounds a hyper young pup.
For this reason, the older dog should be able to retreat any time he wishes. Having a playpen with a door for the older dog is a good method to resolve this. And you’ll want to place this in a quiet area of the home, but not completely isolated.
When you are home, you can close the door to the pen once your older dog has made his way there. For times that you are not home, keep both dogs in their own pens.
Be sure to carefully choose some engaging toys that will help keep the pup busy and distracted. Those that react to his movements or speak like the Pet Qwerks Animal Sounds Babble Ball
can be a lot more fun than pestering your older dog.
Harassment will generally resolve with time as the pup matures and calms down, and the older dog gets accustomed to the new one.
My young puppy is nipping at my other dog.
Young pups, and especially those that are teething, may have not learned all of the rules yet and/or teething pain may cause some lack of self-control.