现在新手学 cisco 的，基本都在用 Dynamips和 PT ，但是很多新手不会使用 Dynamips，或许你看了这篇文章之后，至少会对 Dynamips有点认识，应该基本 都会用了。(Now the beginner's Cisco is basically using Dynamips and PT, but many novice will not use Dynamips. Maybe after you read this article, you will have a little understanding of Dynamips, and it should be basically used.)