I am reconstructing (with a different machine) a network situation with a Windows Server 2008 R2 machine with IIS. For some years, I have run this using a Comcast Business connection. The previous server failed, and I'm replacing it. The router firmware (the way Comcast handles the connection to the Internet) seems to be correct (I specify the IP address of the server in the place for Port Forwarding--TCP, port 80).
But attempting to access the site via my publicly available site name (or its IP) yields "cannot display page." From within my home network, entering http://[that server's IP] gives the desired IIS result.
Can anyone suggest what might be going wrong here?