目前,分布式拒绝服务攻击发生非常普遍,严重威胁到互联网络安全。然而,对于分布式拒绝服务攻击至目前为止还没有非常有效的抵御策略。本文主要讲述分布式拒绝服务攻击的原理及实现方法,并通过实验研究连接次数与实效t的关系,最后介绍目前基于分布式拒绝服务攻击的防范策略。 At present, distributed denial of service attacks occur very often, a serious threat to the Internet security. However, there has not been a very effective defensive strategy for distributed denial-of-service attacks so far. This paper mainly discusses the principle and implementation of distributed denial of service attacks, and studies the relationship between the number of connections and the actual effect through experiments. Finally, the current defense strategy based on distributed denial of service attacks is introduced.