22. When you type in a URL at your browser, you get the corresponding homepage within seconds. Briefly describes what happened at your host, the intermediate routers, and the related server, respectively. Read Section 1.5.2 before writing your answers so that your answer is precise, but do not assume you are running on Linux systems.22．当用户在浏览器中输入一个URL时，会在几秒钟内得到相应的网页。分别简要描述在主机、中间路由器以及相关的服务器上会发生什么。书写答案之前为了使你的答案更为准确，参阅第1.5.2节，但不一定要求运行在Linux系统之上。