If you're seeing this because you were given an IP address to update your DNS and you wanted to test to make sure it was a valid IP we can assure you that it is a valid IP, but you're testing it incorrectly. Please understand that web servers typically host more than a single site and use the Host header to identify which virtual host to load. This is a standard method of hosting and has been in place for quite some time, and yes it is even possible to use virtual hosts with SSL assuming reasonably modern browsers.
Ok, great! Now that you understand virtual hosts and how web servers use them you can still test the site you are trying to test with a simple change to your hosts file. The hosts file is another great part of modern computing because it lets you set a local DNS override just for your computer and it is the same format regardless of operating system.