title: xDebug remote_connect_back not working for AWS EC2 instance
body: <p>The EC2 instance (with Ubuntu 12.04) has setup of <strong>Apache 2.4.6</strong> and <strong>Php 5.5.6 + xDebug 2.2.2</strong>. Apache and PHP were built using make. Everything is working fine, except for xDebug.</p>
  
  <p>Contents of log file and php.ini</p>
  
  <p><strong>php.ini</strong></p>
  
  <pre><code>    zend_extension="/opt/php/lib/php/extensions/no-debug-zts-20121212/xdebug.so"
      xdebug.remote_enable=1
      xdebug.remote_handler=dbgp
      xdebug.remote_mode=req
      xdebug.idekey=xdebug
      xdebug.remote_port=9000
      xdebug.remote_connect_back=1
      xdebug.remote_log="/tmp/xdebug_remote_log.log"
      xdebug.extended_info=1
  </code></pre>
  
  <p><strong>/tmp/xdebug_remote_log.log</strong></p>
  
  <pre><code>    Log opened at 2013-11-29 13:18:35
      I: Checking remote connect back address.
      I: Remote address found, connecting to 117.197.126.1:9000.
      E: Could not connect to client. :-(
      Log closed at 2013-11-29 13:18:36
  </code></pre>
  
  <p>I've exactly the same setup of Apache 2.4.6 and PHP 5.5.6 on a <strong>local CentOS 6.3 machine, that works just fine</strong>.</p>