Why punishment backfires here
Jumping is attention-seeking, and for many dogs even a scolding counts as attention. Kneeing the dog, stepping on paws, or yelling can reduce jumping in the moment while making greetings tense and exciting, which feeds the next jump. Worse, if everyone in the household responds differently, the dog learns that jumping sometimes works, and sometimes is the hardest schedule to extinguish.
Step 1: Four on the floor pays
For one week, become a treat dispenser for paws on the ground. Any time your dog is standing or sitting calmly near a person, mark and reward. You are building a bank account for the behavior you want before you ever address the jumping directly.
Step 2: Train the greeting
Have a family member approach. If paws leave the floor, the person turns sideways and becomes boring, no eye contact, no talking, no pushing. The instant all four paws hit the floor, the person turns back, says "yes," and treats. Repeat. Most dogs connect the dots within a few sessions: jumping makes people vanish, paws down makes people appear with treats.
Step 3: Manage real life
While training, prevent rehearsal. Put the dog behind a baby gate or on a leash when the doorbell rings. Ask visitors to ignore the dog for the first minute. Give guests a treat to toss for calm behavior. Every unmanaged jump at the front door is a training session in the wrong direction.
For kids, add extra management. Kids are exciting, unpredictable, and at face height. Train greetings with calm adults first, then add kids with the dog on leash and an adult handling treats.
Make it stick
Consistency across the household is everything. One person who lets the dog jump "because it is cute" will keep the behavior alive for everyone. Agree on the rules, post them on the fridge if you must, and give it two to three weeks. Behaviors that earned attention for months do not vanish overnight, but they do fade when the payoff stops.