Reporting Services 2008: "HTTP status 401: Unauthorized" Issue

Question

I'm getting the error "The request failed with HTTP status 401: Unauthorized" whenever I try to list the reports on my reporting server. The weird thing is, it works when I run the asp.net application on my dev machine hitting the server reporting services web service url (http://www.example.com/reports/reportservice2005.asmx?wsdl) but when the asp.net app is installed on the server (running iis 7) hitting the same url I get the error. Here's my set up:

Server:

SQL Server Reporting services 2008 (not R2)

Web service url: http://www.example.com/reports/reportservice2005.asmx?wsdl

Client

Created a proxy ReportingServices2005.cs

Web.config has

Code to list reports:

<asp:ListView ID="lvReportList" runat="server">
<LayoutTemplate>
    <ul>
        <asp:PlaceHolder runat="server" ID="itemPlaceholder"></asp:PlaceHolder>
    </ul>
</LayoutTemplate>
<ItemTemplate>
    <li>
        <asp:HyperLink runat="server" ID="hpReportLink" NavigateUrl='<%#Eval("Url")%>'><%#Eval("Name")%></asp:HyperLink>
    </li>
</ItemTemplate>
<EmptyDataTemplate>
    <div>
        No reports to display.
    </div>
</EmptyDataTemplate>

Code Behind:

protected void Page_Load(object sender, EventArgs e)
{
if (!Page.IsPostBack)
{
    string rWebServiceUrl = ConfigurationManager.AppSettings["RSWebserviceUrl"];
    string reportServerFolder = ConfigurationManager.AppSettings["ReportServerFolder"];
    string domain = ConfigurationManager.AppSettings["RSDomain"];
    string userName = ConfigurationManager.AppSettings["RSUsername"];
    string password = ConfigurationManager.AppSettings["RSPassword"];

    objRS.Url = rWebServiceUrl;
    objRS.Credentials = new NetworkCredential(userName, password, domain);

    ReportingServices2005.CatalogItem[] items = objRS.ListChildren(reportServerFolder, false);

    var reportList = from p in items
                     select new
                     {
                         Name = p.Name,
                         Url = String.Format("{0}?reportPath={1}/{2}", ReportViewerUrl, reportServerFolder, p.Name)
                     };

    lvReportList.DataSource = reportList;
    lvReportList.DataBind();

}
}

Answer 1

After several hours of Googling numerous forums and articles, I found that a security feature in Windows Server called "loopback check" (http://support.microsoft.com/kb/926642) was causing the issue. It happened because I have both my report server and IIS server on the same machine and I was using the fully qualified domain name (FQDN: http://www.example.com/reportserver) to access the reports. I solved this by simply using the name of the server instead of the domain name i.e http://mymachinename/reportserver. I hope this helps someone.