title: How Enterprise Library loads hierarchy of external configuration files
body: <p>Please, can someone clarify to me a loading process? Say, you have <code>app.config</code> file for your UI executable. You add Enterprise Library config sources in that file. Each config source refers to another config file, say, one for logging dll, one for data storage dll and one for services dll. In each aux configs you write sections related to Enterprise Library application blocks and some core sections from .NET <code>System.Configuration</code> namespace (for example, <code>connectionStrings</code>).</p>
  
  <p>Now, when configuration system initialized during UI startup, how this hierarchial configuration will be loaded?</p>
  
  <p>As I understand, Enterprise Library will load it's own configuration sections, and will follow file name links and load external configuration files for each <code>FileConfigurationSource</code>. And after will load it's own configuration sections from each external file, mixing them all together.</p>
  
  <p>What about core .NET sections? Will it be loaded also hierarchially by means of Enterprise Library, or I should use <code>configSource</code> attribute for this purpose?</p>