title: Where do the IIS server variables SERVER_NAME and HTTP_HOST come from?
body: <p>Our ASP.NET application is not working at a customer installation because ServerVariables["SERVER_NAME"] and ServerVariables["HTTP_HOST"] return the string "Arcplan". </p>
  
  <p>URLs which we build on the server are then incorrect (we use Request.Url.Authority which appears to use these ServerVariables internally).</p>
  
  <p>The value "Arcplan" stored in the ServerVariables does not correspond to the name of the server or web site or anything that I can find. Maybe the computer was renamed and it used to be called Arcplan?</p>
  
  <p>Does anyone know where IIS gets these values from? Are they stored in a config file somewhere?</p>