Boxer Dog Aggression

Question
I have been happily taking my 4yr old male boxer to the same dog walk for the past 3.5yrs.  He is always very sociable and goes to greet all dogs he meets in the hope of finding a playmate !  He is normally successful, however over the last couple of days we have met other boxers (a different dog each day - 1 male 1 female) and each time it has ended with the dogs fighting.  Can you suggest why this is happening is it a boxer thing ??  

Answer
Boxers recognize other Boxers.

They play rough-- they can literally stand and box one another when playing, bite each others mouths, ears, legs, etc.

They are extremely rough playing.

So are they playing- or can you be assured it is fighting?

No, fighting is not a Boxer-thing at all... rough Boxer-play is though.

Can you tell me more about your term for "fighting" so I can help? Give me examples, please.