FTP is a file transfer protocol. On the website, if you want to share files with others, the most convenient way is to upload files to the FTP server, and others can download the required files through the FTP client program. FTP file transfer needs to be completed through the port. Generally required ports are: 1. Control link -—TCP port 2 1. Controller side. Used to send instructions to the server and wait for the server to respond. 2. Data link-TCP port 20. Data transmission port. Used to establish a data transmission channel. It is mainly used to send files from the client to the server, from the server to the client, and from the server to the client. In order to adapt to different network environments, FTP supports active connection and passive connection. These two modes are mainly aimed at the data link and have nothing to do with the control link. FTP security risks: First, FTP server software vulnerabilities. Second, clear the password. Third, the FTP flag. Fourthly, port scanning is carried out through FTP server. 5. Data hijacking. Security policy of FTP: 1. Use a more secure system and FTP service software. Second, use ciphertext to transmit user name and password. Third, change the logo of the service software. Fourth, strengthen the security of the protocol. SFTP is the abbreviation of Secure File Transfer Protocol, which is a secure file transfer protocol. It can provide a secure encryption method for transmitting files. Its grammatical function is almost the same as ftp. SFTP is a part of SSH, which is a safe way to transfer files to the Blogger server. it ...