title: Proxy Connection Error when trying to install packages with pip in anaconda environment
body: <p>I'm trying to install a package (tensorflow) utilizing pip in an anaconda environment <code>pip install --upgrade tensorflow</code> on Windows Server 2016, resulting in the following error:</p>
  
  <blockquote>
    <p>Retrying (Retry(total=4, connect=None, read=None, redirect=None, status=None)) after connection broken by 'ProxyError('Cannot connect to proxy.', NewConnectionError(': Failed to establish a new connection: [WinError 10061] No connection could be made because the target machine actively refused it',))': /simple/tensorflow/</p>
  </blockquote>
  
  <p>I'm in a corporate network and the proxy for anaconda is set.</p>
  
  <p>I've already tried the following things which don't help, the same error is still popping up:</p>
  
  <ul>
  <li>disabling firewall </li>
  <li>installing another package with pip (matplotlib)</li>
  <li>adding the flag <code>--proxy=http://myproxy.bla:8080</code> to the pip command </li>
  <li>adding the flag <code>trusted-host=pypi.python.org</code> to the pip command</li>
  <li>re-installing anaconda</li>
  <li>downloading the whl-file of tensorflow and <code>pip install</code> that. However, during that process, pip throws the error again when downloading any other package (e.g. astor)</li>
  <li>installation of other pip and python versions in other anaconda environments</li>
  </ul>
  
  <p>Any help or hint is appreciated!</p>