Traceroute 是一个跟踪从 A 到 B 的路径的应用程序。（A 是您的位置，B 是您要跟踪的服务器）。
基本算法如下：
send UDP with TTL = 1
Server A1 received, and return ICMP packet to A because TTL is expired.
--> know first machine between. For example A1.
send UDP with TTL = 2
Server A1 received, and send this UDP to server A2.
Server A2 received, and return ICMP packet to A because TTL is expired
--> know second machine between. In this example is A2.
Do it until to B. …