You can determine whether multiple websites are hosted on an IP address by analyzing the DNS records. If multiple names point to the same IP address, then the host header value is used to uniquely identify the website. DNS tools such as dig and nslookup can be used to identify domains returning similar IP addresses.

You can use the http://ipneighbour.com/ website to identify whether other websites are hosted on a given web server. The following example shows several websites related to Wikipedia hosted on the same IP address: