Nothing will alienate your neighbors faster than an inappropriately barking dog or one that barks at all hours of the day and night. On the other hand, it is comforting to know that your boxer could sound an alarm if needed. So, barking, as such, is not so bad, but excess, incessant barking is very bad.
The first way to address excess barking is to train your boxer to bark on command. After all, if he can bark on command, he can stop on command too, since he knows from other training what commands and their opposites mean (remember the on-and-off the furniture rules, jumping up on people and not jumping up on people?). If you train this, you have the added advantage to allowing your boxer to bark at strangers you don't know or in other situations where you might like to have a barking dog.
Barking is traditionally understood to occur for the following reasons: anxiety, boredom, and attention-seeking due to loneliness. In boxers, there may be one more category: barking out of sheer joy. The happy barker is not anxious, bored, or lonely but just overjoyed with life and wants to tell the world.
There are a number of ways to teach your dog to bark and not bark on command. The first is pretty direct. When your boxer barks, you say, “Good bark.” He will be very surprised and not understand what you are saying at first. Just like every other situation, if you are consistent with your praise, he will come to understand what “Good bark” means. And once he does, then you can tell him to bark, and he should bark. Once he will bark on command, you now have the option of saying, “No bark,” when he does bark. If you have trained your other alternative behaviors correctly and your boxer understands the command, your boxer should know what this means and stop barking.
A second way to train your boxer to bark on command is to make silly sounds yourself, including barking like a dog. Your boxer will look at you like you have lost your mind, but he generally gets the idea pretty quickly, and will make some kind of sound. When he does, praise him excitedly. If you do this several times a day for a week or so, your boxer should be able to bark on command pretty easily. Then, of course, once he can bark on command, you can also stop him more readily. Combining the two methods usually helps to get barking on command the fastest.
While putting barking on command while you are around can be an effective way to stop excess barking, if your boxer barks while you are not around, training him to bark on command may or may not help.
Since excess barking is usually a stress release of some kind, it is what as known as a self-rewarding behavior. In other words, it is worth it for him to bark because it helps to diffuse any negative emotions he might be feeling. This is the kind of barking that is harder to break. In these cases, especially since most people are out of their homes eight or more hours a day to work, barking can be a hard problem to address.
Most dogs that are tired are not inclined to bark. If you can get up an hour or so earlier to take your boxer for a long walk or run, you will do much to prevent problem barking. Or get up an hour earlier just to train him. Anything that tires him out will help to prevent barking. This helps especially if he is an anxious or bored barker. Another thing that can help is to hire a dog walker to take him for an additional walk during the day, or you can take him to doggy day care.
But what if you don't live in an area where dog walkers or doggy day care are available, and you commute so much that you don't have an extra hour in the morning to walk or train? Well, if you have still decided that a boxer does fit your lifestyle choices, you may need to get a bark collar.
The most humane bark collar is one that is instructional in that it emits a sound that is audible to humans before it emits a high-pitched sound audible only to dogs. The warning sound helps the dog to understand that if they do not stop barking, an unpleasant consequence, the high-pitched sound, will occur. This collar runs on batteries.
Another collar that has gained in popularity is a citronella collar. It releases citronella, a natural strong-smelling substance (not unpleasant to humans), if the dog barks. Dogs do not like the smell of citronella, so they will tend to stop barking when the collar releases the smell. This type of collar gives no other warning to alert the dog to the coming correction. Some citronella collars need batteries and vials of citronella to work. Some just need citronella.
The final collar is the original bark collar, which gives the dog a mild to strong shock if he barks. This collar is also battery operated and also gives no warning sound to let the dog know that a correction is coming.