title: Apache and Content-Range
body: <p>I am trying to implement support for Content-Range in PHP-generated files. When a browser sends Range request my script gives correct bytes and it works well.
  But while testing how Content-Range looks when downloading a PDF from Apache server I realized the first request from a web browser to my server does not contain Range header but somehow server still doesn't return full file and only 32 kB.</p>
  
  <p>On this screenshot you can see that Firefox sends 5 requests to Apache for my_pdf.pdf and Apache each time responds with 32-192 kB. The whole PDF is 28 MB. Requests 2-5 do contain Range request. But the first request- highlighted does not. You can see on the right that Content-Length is 28 MB but that Apache returned only 32 kB.</p>
  
  <p>So my question is- how did Apache know to return only 32 kB and not the whole 28 MB PDF file?</p>
  
  <p><a href="https://i.stack.imgur.com/29McL.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/29McL.png" alt="enter image description here"></a></p>