There are several smaller dogs that encounter problem with a bigger dog greeting them. There are also larger canines which will question the greeting of the smaller pup. Familiarity is the key as is exposure. The greater breeds that a puppy could be exposed to the better. The mystery of a strange creature dissipates whenever a similar foe continues to be foiled before.
The Most significant skill that the cute, cuddly canine learns is how it can say “hello” to its fellow dogs. The initial sniffing of the tail to the nose to nose greetings, your dog that does not learn the proper way to say “hello” is destined to have behavioral problems later in life. There’s a right way to get to know another dog and a wrong way.
Misbehaving pups that are too nosey or aggressive in their greetings often find out the hard way. From a nip about the nose to some guttural growl, the result would be harsh to him.