Source: http://serverfault.com/questions/291539/risks-of-using-active-ftp-mode-instead-of-the-passive-mode In a nutshell: FTP connections consist of two streams: command (control) and data When a socket is opened and code does not explicitly bind to a port, the OS will consume a high numbered port in its ephemeral port range (sysctl -a | grep ip_local_port_range) Non-root processes must use ports >1024 Active Mode … Read moreRisks of using active FTP mode instead of the passive mode
Source: http://stackoverflow.com/questions/1699145/what-is-the-difference-between-active-and-passive-ftp Active and passive are the two modes that FTP can run in. FTP uses two channels between client and server, the command channel and the data channel, which are actually separate TCP connections. The command channel is for commands and responses, the data channel is for actually transferring files. It’s a nifty way … Read moreWhat is the difference between active and passive FTP?