We are running Windows Server 2008 R2 with IIS 7.5 and have 4-5 Classic ASP sites to install. The main site is stored in wwwroot and the other sites are stored in folders below wwwroot.

We have 1 IP address for the server. How do I configure IIS to allow folks to browse/test the sites before domain names are pointed to te server?

When I setup one of the sites in a subfolder of wwwroot and assign a separate port to it, I receive a message stating:

Config Error Cannot add duplicate collection entry of type 'add' with unique key 
attribute 'value' set to 'index.asp'  

The error points to web.config in the given sites' folder as follows:

            <add path="*">
                    <add provider="ASP" verbosity="Verbose" />
                    <add provider="ASPNET" areas="Infrastructure,Module,Page,AppServices" verbosity="Verbose" />
                    <add provider="ISAPI Extension" verbosity="Verbose" />
                    <add provider="WWW Server" areas="Authentication,Security,Filter,StaticFile,CGI,Compression,Cache,RequestNotifications,Module,FastCGI" verbosity="Verbose" />
                <failureDefinitions statusCodes="400-999" verbosity="Error" />

How do I remedy this error and permit IIS to render the site?


Put each ASP app in its own site. Bind each site to the same IP, but use a different Host Header on each site. Register those host headers in your local DNS server.

  • Thanks. By local DNS server, do you mean the one on the web server? – SidC Oct 24 '12 at 0:14
  • I mean the DNS server that your local clients use to resolve DNS queries - if you're on an Active Directory domain, the DNS servers are usually the Domain Controllers. If you're not using AD and perhaps using a router to handle your DNS queries, you may have to resort to using entries in your hosts file (%SystemRoom%\System32\Drivers\etc\hosts) – Chris McKeown Oct 24 '12 at 7:55
  • This helped!! Is there a setting I need to change to browse each site by IP and port from a browser independent of the server? – SidC Oct 25 '12 at 22:26
  • You can't browse each site by ip address because they all run on the same ip address. You need to use a a valid URL to browse each site and you need to have each site configured with host headers for the relevant URL. So for www.mydomain1.com the host header would be www.mydomain1.com. – joeqwerty Oct 26 '12 at 15:52
  • @joeqwerty The domains in the host headers are live and hosted by another company at this time. Thus, when I browse ourdomain.com it resolves to the old server. How do we setup the new server to test prior to pointing the domains from the old server? – SidC Oct 26 '12 at 19:34

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