some cases, can search history ip, I often use http://www.securityspace.com/sprobe/doprobe.html. And more you can to search on google. And if the website have some can send requets features such as get remote image and more. any send requets features from website real server can be exploit. we can listen port on ourself server to get real ip other you can try bind ip address use hosts file to verify ip. more method need discovery for yourself . But these method is not adequate in all cases.