title: How does Docker use ports 2375 and 4243?
body: <p>I see various instances of ports 2375 and 4243 being used for seemingly the same thing while searching the internet. Also, my local machine requires I use 2375 to connect whereas when I push it to our CI server it requires it be set to 4243.</p>
  
  <p>What does Docker use these ports for and how do they differ?</p>