ftp State Engine

The ftp state engine is used for FTP sessions. This state engine understands the control protocol used by FTP sessions including parsing PORT commands. It supports both traditional and PASV modes. The ftp service is typically the only service that uses this state engine.

The discriminator for the ftp state engine is the port number of the control connection, which is normally 21. The port number of the data session is always one less than the control connection unless this is overridden by the parameters below.

The ftp state engine has the following parameters:

• Lifetime of idle control session in seconds - Specifies the lifetime of an idle control session (default = 600 seconds)

• Lifetime of idle data session in seconds -Specifies the lifetime of an idle data session (default = 600 seconds)

• Flag value - Flag value is a set of bits. If bit 0x01 is set, non PASV data sessions are allowed to originate from a port other than one less than the control port. This feature is sometimes needed to communicate with FTP servers that incorrectly implement the FTP protocol so they do not need to run the data connection as root (default = 0).