[CloudFlare] Understanding and Mitigating NTP DDoS

[quote=CloudFlare]Over the last couple of weeks you may have been hearing about a new tool in the DDoS arsenal: NTP-based attacks. These have become popular recently and caused trouble for some gaming web sites and service providers. We’d long thought that NTP might become a vector for DDoS attacks because, like DNS, it is a simple UDP-based protocol that can be persuaded to return a large reply to a small request. Unfortunately, that prediction has come true.[/quote]

http://blog.cloudflare.com/understanding-and-mitigating-ntp-based-ddos-attacks