The paper gives more description of working principle of FTP protocol,the method to set FTP server based on Linux system as well as security service,etc. Several excellent FTP practical softwares are introduced also.

• 主要介绍了FTP协议的工作原理 ,基于Linux系统设置FTP服务的方法以及服务的安全性等问题 ,最后还介绍了几个优秀的FTP实用软件。