1、掌握FTP协议如何实现客户端和服务器端的交互 2、实践中对FTP协议的具体数据报的分析 Sniffer比课本上提供得数据包协议分析更为详尽。FTP协议就是不断得实现客户端和服务器端得交互，通过相互之间的数据包发送来进行文件的上传下载以及和客户端及服务器端的响应。对于FTP协议的分析能让我们更能体会到网络的双向以及及时响应的重要性，对于网络的具体认识有了进一步加深-one, grasp how to achieve FTP client and server side of the two interactive practice, the FTP protocol specific data analysis of Sniffer than textbooks to provide packet data from more detailed analysis of the agreement. FTP is constantly in achieving client and server in interaction, through the correlation between the data packets sent to the documents and to upload and download the client and server-side response. For the FTP protocol analysis allows us to appreciate better the two-way network and the importance of timely response, the network has been further deepened understanding