We are having some issues with configuring multiple EPiServer sites against one codebase. The default siteHosts (<siteHosts><add /></siteHosts>) is always getting used because it isn’t matching on other configured site hosts. For example, with http://www.someurl.com/ as one of additional sites in the configuration, it doesn’t match on it and uses the default site configuration instead. Upon investigation of the problem, I found that the HttpContext.Current.Request.Url.Host is different from the URL in the browser. The host is that of the computer name (http://somecomputer.domain.internal) instead of the IIS configured host name (http://www.someurl.com/). Any ideas as to what would be causing this? It seems to be something that EPiServer is doing to the Http Request object. This only happens with EPiServer sites which leads me to believe that the request is somehow modified by EPiServer. Please advise.
Do you have an enterprise license? It will not work with a "normal" license.
You do not include http/https in the sitehosts section? (you shouldn't)
Any proxy servers or firewalls involved in the infrastructure? There are several places that could be tampering with the network traffic... EPiServer does not behave like you describe unless you have some custom url rewriting code.