Is there a way to access the website via IP rather then domain name e.g. http://192.168.0.99/web1/ or http://192.168.0.99/clientname/ ???
No, you can not access sites like this. But if you assign a different IP address to every site you can access them by IP.
external/internal ip address ?? So there's absolutely no way for me to access my sites using my external/internal ip address ?? That's a needed feature for test sites or pre production sites which there is not a domain name yet..
