It is better to host multiple cross-linked websites on different Class C IP ranges. This tool is very much useful in checking that if same class C IP range is hosting two or more domains and this thing helps us in knowing about duplicate IP addresses and class C blocks. You can enter minimum 2 URLs and maximum 20 URls in the the textbox to get the result.

Never share an IP address on other websites as it will have negative impact on your website and it will lower the Page Rank of your website. If by mistake you share your website's IP address on a website that has been blacklisted by search engines due to inappropriate content then it will have negative impact on your website as well.