title: CURL --interface not working: "Couldn't bind to ..." error
body: <p>I'm trying to use curl with another IP address from the ones available in the server but I get this error:</p>
  
  <pre><code>curl --interface 41.141.41.23 http://www.google.com
  </code></pre>
  
  <p>curl: (45) Couldn't bind to 41.141.41.23 (its just an example address)</p>
  
  <p>It only lets me do it with the main one and only by the interface name:</p>
  
  <pre><code>curl --interface eth0 http://www.google.com
  </code></pre>
  
  <p>I'm using:</p>
  
  <p>Ubuntu 12.04</p>
  
  <p>curl 7.22.0 (x86_64-pc-linux-gnu) libcurl/7.22.0 OpenSSL/1.0.1 zlib/1.2.3.4 libidn/1.23 librtmp/2.3</p>