Coincidentally I have just setup the same environment.
On the configure stage of the fog client install, make sure that the server address (which defaults to fogserver) matches the ip address or DNS name of your server that is also defined in the certificate that can be found at
http://<Fog server address>/fog/management/other/ssl/srvpublic.crt

I’m assuming the client installer tries to download this certificate from your server and when it can’t find it, it fails