Pup Nipping Other Dogs Ankles

I took Bobby to the park as usual today and for the first time while he has been off his lead he came across another dog - a chocolate lab that I knew well from walking my previous dog, so I knew he had a good temperament.

Initially Bobby was a bit unsure and kept his distance, while the lab treated him with disdain and ignored him. After a while though Bobby started to get a bit bolder, running in circles around the lab and then charging in and looking as if he was going to nip its ankles.

He never actually made contact, pulled away at the last minute so no damage was done but I was a bit bothered by it - if he does it with a dog who was not so laid back there might be trouble.

Is this part of the puppy mouthing/biting thing, which I am trying to get him to stop doing with us, or something else do you think, and what is the best way to deal with it?

I have been doing all the training myself with him, so maybe he now needs to get to some classes where he learns how to be with dogs?

this is exactly what my dogs sister did when she was very young now shes always barking at other dogs. as a pup your dog is just playing but also testing its bounderies with other dogs.if he is not stopped by another dog or by you he will keep believeing it is exceptible and may become dog aggressive when he gets older. when he starts doin it try distracting him with a toy such as a tennis ball to discourage this behaviour

Thats what was in the back of my mind to be honest. I want him to be a well behaved dog with other dogs.

I wonder if I keep him on his lead would that help?