Kona takes a minimum of one walk per day (RARELY one), usually three.

I walk him at 5am - our neighborhood is still quiet and we have a nice, one mile loop I take him on. Every few walks we take a different route, just to keep things interesting.

My wife, daughter and I will walk him other times of the day. Sometimes alone, sometimes in other combinations.

Today my daughter walked Kona alone (she does this often), and while they were out, Kona tried to jump on somebody as they passed by.

She couldn't read whether Kona was being aggressive, protective, or just wanted to meet him, but it gives me a little cause for concern.

I'm considering a muzzle strap on his harness; all advice welcome!

Mika does this sometimes... Nothing aggressive in our case, but still unacceptable.  You can work on desensitizing him to other people.  You can correct him when he does it or redirect him before he does it.  A harness offers zero correction... and, with our dogs, makes them pull harder. A "Leave It" command would also work in this case.

Additionally, he may need more than walks... I would guess a 5 mile run would help keep him focused on the task at hand.

I don't know how old your daughter is, but my 16 year old would get pulled off her feet if Max or Mika decided to bolt somewhere.  We use prong collars whenever she walks them alone.

Lastly, it may be worth enrolling in a group obedience class.  You daughter could even be the one who takes the class with the dog if she's old enough and it makes sense to you and the instructors.

My first bet is a friends with everyone dog to say hello BUT I not witness interaction.

I use a prong collar bone my guys. Gives me a way communicate with me dogs with minimal input. A slight flick the wrist and they slow down, a minimal upward flick they know to sit. May be helpful particularly for your daughter is you can trust her not to yank the dog.

I have only had kenzi try to jump on someone one time and it was a guy with a beard. She's been around guys with beards before but not an unkempt beard as this one was. I would focus on what could have been different about this person if this is a one-time or first-time thing. If you can pinpoint what could have been different I would work on desensitizing that rather than taking a dog that otherwise does well and implementing gear to thwart a behavior that's only happened one time.

#1 Prong collar, no harness. When he goes to jump up or charges another dog, give him a big firm snap correction. If your doing it right he should yelp. No verbal command, that way the correction is not from you, it's just happens every time he does the undesirable.

The way our trainer explained it, if a dog is running through the woods and smashes into a tree, he realizes real quick not to smash into trees. The tree is not being cruel, it's just cause and affect. Our boy has gotten much better. His biggest problem is over-excitement with other dogs. When we approach other dogs I get out a treat and get his attention on me and he gets a treat when we pass the other dog peacefully. It's a work in progress.

Z'ev used to go full on attack mode when seeing another dog, Ami full on let's play, ooo ooo a friend!!! I use prong collars and ecollars on both paired with a predictable pattern on walks. It's either see a car coming (we're on rural roads, no sidewalks) and get as close to the ditch as possible then sit. See another dog, then its heel and "on by" Fortunately, in our area a free running dog is extremely rare - free running usually means a dead dog from cars (very few cars so dogs don't get accustomed to them and the few that are are FAST. Also, very hilly so visibility is short.

At this point, Z'ev has been ecollar trained for almost 2 years and Ami for about 4, I rarely have to engage their collars these days, they wear them, know they are on, but the verbal command is enough. Off leash in the woods? That's different -a deer usually requires ecollar reminder.

Forgot to mention, another magic bullet for us is when he's being unruly I do some training move...quick 180 degree turn-arounds, quick 90 degree lefts with high knees. Brings his attention from the outside world back to you. Just going through your training routine before heading out on the walk usually helps a lot.

Thanks for all the help! - I'm running out for a prong collar soon!

He's had one other incident while walking with me, but it was a different setting - 4:30 am on the jetty (sidewalk on top), a fisherman climbed the rocks in front of us (with a short halibut! ). Something about his demeanor (worried I was F&G, just a bad dude, etc) set Kona off. VERY quickly he dropped low and leaped forward - aggressively, he was not trying to say hi! He's never done that with me before, so I'm trusting Kona's instincts - and focusing on walk training.

@dvflyer - re: 0 correction with a harness. We did find a method to control Kona with a harness: When Kona bolts forward, we convert the straight line shock laterally into a circle - I think similar to what @windfishin is describing.  But it doesn't give correction to the behavior as you mention.

Skatejoring has helped with indulging the pulling instinct too (and it's FUN!)

I think the prong collar will accelerate the rate of his training greatly!

Kona_18, make sure you get a Herm Sprenger. The tips rounded and the prongs are angled. Also, you probably VB only need the small with maybe an extra link or two.

Here's a link with info about sizing, using, buying.
https://leashesbydesign.com/page/

Kona- Here is an image on how to properly place a prong collar.  99% of the people I see are not doing it correctly.  It should be placed very high on the neck and adjusted so that it is tight and won't slip down.  It may seem unnatural at first.  A regular collar positioned in this fashion will also become instantly more effective but because they are smooth, they almost always work themselves lower on the dog's neck.

As Amy mentioned, Herm Sprenger is the brand to choose. I would avoid any quick release options. We even use Fur Saver collars in conjunction since prong collars have ocassionally come off. I ordered two off of Amazon. One of them I'm fairly sure is fake, so be aware of who you buy from.

Additionally (and anecdotally), I think using the prong collar may contribute to more knots in their fur around their ears... at least in our wooly coated Max. You may need to brush the area more often.

Ugh, Mike - the behind the ear tangles. Ami gets them all the time, prong collar or not. We have a before bed ritual - I hand feed a tablespoon or two of kibble, piece by piece with one hand while the other gentle rubs his ears (that's what he thinks) while exploring and detangling the days accumulation of mats. A never ending battle. Two days ago, he came in with about 30" of multiflora rose pruning caught in his rear pants!

As for the Herm Sprenger - the scissors quick release has a bad reputation. I use the side release buckle that is sold on the Leashes by Design gal. I've never had a problem with it. I do however, back up my prong collar with a large carabiner attached to the dead ring on the prong collar to his flat collar. Leashes by Design also sells a 6" connector to do the same thing - like a tiny mini leash with snaps on both ends.