This is a whitepaper describing techniques and defenses to mitigate against distributed denial of service attacks. Written in German.
You can download it from the following link: https://packetstormsecurity.com/files/download/94300/DDoS_Schutz_-_Abwehr_von_DDoS_Attacken.pdf
Source: https://packetstormsecurity.com/files/94300/How-To-Protect-Against-DDoS-Attacks.html