There are things that make us interesting to dogs. Sudden adrenaline rush when a dog runs out in front of you, they sense a change in smell. You can see when the dog is not in the mood, then you should slowly move away from it without turning your back or continue slowly where you went.
A raised and stiff tail is an indicator of aggressive behavior at a given moment. Now, if the dog walks at you from a certain distance, bend down and pretend to be picking up a stone (it distracts them). If they continue to approach a strong voice it is not a good idea if you are still approaching them (kicking the ground gives the best results). If you are very close to wearing any kind of spray in your bags, the strong odors deter them.
Dogs that fly like mutts out of the yard are not aggressive, especially if they bark, if they remain silent ... well then you have a real problem. The excursion function is "clear out of my territory" and it's generally nothing dangerous, I have a couple of them in the street they never did anything to me.
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From @sarakey