> For the complete documentation index, see [llms.txt](https://book.bsdcn.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://book.bsdcn.org/ask/flat/chapter-36-file-transfer-protocol-ftp/di-36.1-jie-wen-jian-chuan-shu-xie-yi-ftp-gai-shu.md). # 36.1 Overview of File Transfer Protocol (FTP) The File Transfer Protocol (FTP) provides users with file upload and download services. ## Overview FTP (File Transfer Protocol) is one of the earliest application-layer protocols in the TCP/IP protocol suite, used for network file transfer. Setting up an FTP server on FreeBSD enables fast file transfer and sharing in both LAN and internet environments. This section introduces three commonly used FTP server software packages: | Software | Features | Use Cases and Target Users | | --------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------- | | Pure-FTPd | ISC license (functionally equivalent to the 2-clause BSD license), security-first, supports multiple operating systems, relatively complete implementation of the FTP protocol specification | Provides high flexibility for ISPs and hosting services, suitable for beginners | | ProFTPD | GPLv2 license, supports multiple operating systems, single main configuration file, strong extensibility | Suitable for users familiar with Apache HTTP Server (similar syntax) | | vsftpd | GPLv2 (with exception clauses) license, supports IPv6 and SSL encryption, supports virtual users, virtual IPs, fine-grained user and IP control, bandwidth limiting | Oriented towards production environments | ## Security of the FTP Protocol The standard FTP protocol transmission process is insecure: both passwords and data are sent in plaintext, and no encryption is applied by default. ~~Perhaps completely phasing out the FTP protocol is the only solution.~~ > **Note** > > Running an anonymous FTP server may pose potential risks. In particular, careful consideration should be given to whether anonymous users are allowed to upload files. FTP sites may become venues for unauthorized commercial software transactions, or even lead to more serious consequences. If anonymous FTP uploads are required, ensure that permissions are set correctly so that other anonymous users cannot read files before the administrator reviews them. ## FTP Client Usage Examples Using telnet to test the FTP service: ```sh # telnet localhost 21 Trying 127.0.0.1... Connected to localhost. Escape character is '^]'. 220 FTP Server ready quit 221 Goodbye. ``` The above command is used to test whether port 21 of the FTP service on the local host is available. Using the `ftp` command provides a convenient way to connect to an FTP server. Its basic usage is as follows: ```sh ftp [options] [IP address] ``` FTP commands: ```sh put Upload bell Sound a beep when file transfer is complete dir/ls Display files and folders in the current directory cd Change directory delete Delete a file get remote_file Download a remote file from the server bye End the session with the server ``` In addition, the following FTP protocol commands can be sent to the server via `quote`: ```sh quote acct [account_info] Submit account information (sends the ACCT command) quote feat Display the features supported by this server (sends the FEAT command) ``` Operation example: ```powershell PS C:\Users\ykla> ftp 192.168.179.150 # Connect to the specified FTP server using the FTP client Connected to 192.168.179.150. 220 Welcome to blah FTP service. 200 Always in UTF8 mode. User(192.168.179.150:(none)): ftptest 331 Please specify the password. Password: 230 Login successful. ftp> ls # List files and subdirectories in the current FTP directory 200 PORT command successful. Consider using PASV. 150 Here comes the directory listing. FreeBSD完全攻略QA版 (冯宝坤，陈子鸿编著, 冯宝坤, 陈子鸿编著, 冯宝坤, 陈子鸿).pdf FreeBSD技术内幕 ((美) Michael Urban，(美)Brian Tiemann著 智慧东方工作室译).pdf 哲学史期末.docx 马克思主义哲学原理.doc 226 Directory send OK. ftp: 288 bytes received in 0.00 seconds 96.00 KB/s. ftp> delete 哲学史期末.docx 250 Delete operation successful. ftp> dir # Display a detailed file listing of the current FTP directory, including permissions, size, and modification time 200 PORT command successful. Consider using PASV. 150 Here comes the directory listing. -rw------- 1 1003 14 147170778 Mar 06 15:39 FreeBSD完全攻略QA版 (冯宝坤，陈子鸿编著, 冯宝坤, 陈子鸿编著, 冯宝坤, 陈子鸿).pdf -rw------- 1 1003 14 47037557 Mar 06 15:39 FreeBSD技术内幕 ((美) Michael Urban，(美)Brian Tiemann著 智慧东方工作室译).pdf -rw------- 1 1003 14 591146 Oct 20 11:28 马克思主义哲学原理.doc 226 Directory send OK. ftp: 435 bytes received in 0.01 seconds 54.38 KB/s. ftp> get 马克思主义哲学原理.doc 200 PORT command successful. Consider using PASV. 150 Opening BINARY mode data connection for 马克思主义哲学原理.doc (591146 bytes). 226 Transfer complete. ftp: 591146 bytes received in 0.01 seconds 42224.71 KB/s. ftp> ls 200 PORT command successful. Consider using PASV. 150 Here comes the directory listing. FreeBSD完全攻略QA版 (冯宝坤，陈子鸿编著, 冯宝坤, 陈子鸿编著, 冯宝坤, 陈子鸿).pdf FreeBSD技术内幕 ((美) Michael Urban，(美)Brian Tiemann著 智慧东方工作室译).pdf 马克思主义哲学原理.doc 226 Directory send OK. ftp: 266 bytes received in 0.00 seconds 66.50 KB/s. ftp> lcd Local directory now C:\Users\ykla. ftp> put UOS使用打印机.pdf # Upload a local file to the FTP server 200 PORT command successful. Consider using PASV. 150 Ok to send data. 226 Transfer complete. ftp: 1269989 bytes sent in 0.04 seconds 36285.40 KB/s. ftp> dir 200 PORT command successful. Consider using PASV. 150 Here comes the directory listing. -rw------- 1 1003 14 147170778 Mar 06 15:39 FreeBSD完全攻略QA版 (冯宝坤，陈子鸿编著, 冯宝坤, 陈子鸿编著, 冯宝坤, 陈子鸿).pdf -rw------- 1 1003 14 47037557 Mar 06 15:39 FreeBSD技术内幕 ((美) Michael Urban，(美)Brian Tiemann著 智慧东方工作室译).pdf -rw------- 1 1003 14 1269989 Mar 27 15:13 UOS使用打印机.pdf -rw------- 1 1003 14 591146 Oct 20 11:28 马克思主义哲学原理.doc 226 Directory send OK. ftp: 515 bytes received in 0.01 seconds 46.82 KB/s. ftp> bye # Disconnect from the FTP server and exit the client 221 Goodbye. ``` FTP downloads files to the current working directory by default (i.e., the directory where the ftp command was started). --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. 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