[Judi W]

Sorry to tell you this, but the socialization needs to go on continuously well until full adulthood and adult behaviors are solidified. The reason for this is that the doggy communication and social skills that work as a pup are not the same ones needed as an adolescent and certainly not the same ones expected within the species as an adult. Also, the dog is not looking at the world through the same eyes from one stage to another.

I don't know what kind of training classes you might have available where you are (if any), but if you can find some, jump in and stay there for a couple of more years. That way he will become accustomed to behaving in a mannerly way around other dogs and still listen to you. In the meantime, when you meet up with someone, yes, put on your leash, let him know that he can continue to listen to you and obey your instructions and not feel free to interact with the other dog without your express permission. Until he gets his head on straight, don't give him that permission. Put him in a sit while you say your hello's and chat (give yourself some distance so that he will be back from the other dog) and then go on your way before you get shunned. For a while, until he gets the idea, don't even go that close, simply step off to the side, call your hello and keep moving in a business like manner. It won't hurt him a bit to be called to heel now and then when on your walks. As he starts learning that part, then you can move closer and put him in a sit, then keep going. Expand upon this theme until he understands that you will control his behavior.