title: By default, can a docker container call host's localhost UDP?
body: <p>I have a docker container, and also installed on the VM a daemon listening for UDP on port 8125. The container sends data with UDP protocol on this 8125 port.</p>
  
  <p>I was trying to open the port by starting the container with the <code>-p 8125:8125/udp</code>, but I'm getting the following error:</p>
  
  <pre><code>Error starting userland proxy: listen udp 0.0.0.0:8125: bind: address already in use
  </code></pre>
  
  <p>Which makes sense because the daemon is already listening on this port. </p>
  
  <p>So how can I configure Docker so that the container can send UDP payloads to the external daemon ?</p>