Question

I am using an HttpWebRequest and passing in an Address which is an IP. I then set the host to a garbage value. When I call GetResponse() I am getting an OK even though I would expect this to fail since the host is garbage.

HttpWebRequest request = (HttpWebRequest)WebRequest.Create(String.Format("http://10.10.10.10/Default.aspx"));
request.Host = "blah.blah.blah";
request.ContentType = "text/xml";
using (HttpWebResponse response = (HttpWebResponse)request.GetResponse())
{
    if (response.StatusCode == HttpStatusCode.OK) { /*always enters here */ }
}

Why is the response coming back as OK? Shouldn’t the garbage host cause this to fail?

Answer 1

HttpWebRequest.Host Property:

Get or set the Host header value to use in an HTTP request independent from the request URI.

Using the Host property to explicitly specify a custom Host header value also affects areas caching, cookies, and authentication. When an application provides credentials for a specific URI prefix, the applications needs to make sure to use the URI containing the value of the Host header, not the target server in the URI.

So there is no effect of .Host to the general request, you change some additional behavior.