title: ipython notebook listening on all IP addresses?
body: <p>When I launch IPython/Jupyter Notebook, I get the following warnings:</p>
  
  <pre><code>WARNING: The notebook server is listening on all IP addresses and not using encryption. This is not recommended.
  WARNING: The notebook server is listening on all IP addresses and not using authentication. This is highly insecure and not recommended.
  </code></pre>
  
  <p>What does "listening on all IP addresses" mean?  And how do I fix this?</p>