Would it be on-topic at serverfault ? There are already some questions about this at security.stackexchange, for example [this one][1] which mentions a few options in the second answer, or [this other one][2] which mentions mitigation partners. [1]: http://security.stackexchange.com/questions/30352/how-to-mitigate-a-ddos-from-botnet-on-your-website-that-comes-from-random-ips [2]: http://security.stackexchange.com/questions/114/what-techniques-do-advanced-firewalls-use-to-protect-againt-dos-ddos