中文摘要：

介绍了Do S攻击的概念、原理、攻击手段、危害性及其难以防范的原因,并阐述了Do S攻击的防范技术,最后预测了Do S攻击技术和防范技术的未来发展趋势。

英文摘要：

The concept principle, means of attack, harmfulness of DoS attack and the cause of its hard to prevent were introduced. The DoS attack prevention technology was elaborated. Finally the future development trend of DoS attack technology and prevention technology were predicted.