Did you know it is considered better to host multiple cross-linked websites on different Class C IP ranges?
This nifty tool checks if the same Class C IP range is hosting several domains, which can help you find duplicate IP addresses and Class C blocks. Just enter a minimum of two, or more to 20, names of domain (one domain per line) in the large text box and begin your test.
Once you share an Ip with other websites, it could have a negative effect on the PR and SEO efforts on your own website. Once you share an Ip with other websites which have been blacklisted or intentionally blocked by se's because of inappropriate content, it has a negative effect on your website aswell.
Please let us know that if you want more functions in this small software, we will listen your suggestion and add them :)