I have 4 intranet application that resides in IIS. The applications are simple and they have been made with classic asp. But there is a need one of them to expose it to our client outside the company. We have a pool of IP's (because we have a mail server-ms exchange) and we use one of IP's for the web server. So for this IP we made a port forwarding for port 80 to the web server. How must the IIS be configured to response also in internet requests except intranet?
I think the best thing to do would be to map a virtual directory for the application that you can then expose through a new site entry in IIS, using an externally accessible IP address.
I would caution against changing any IIS settings for your intranet for this. You will need to make sure the externally available site cannot access any other internal resources and lock it down with appropriate security measures.