FTP

Oprettet torsdag 18 juni 2020

Definition of FTP
File Transfer Protocol (FTP) is an application layer protocol. FTP is a mechanism provided by TCP/IP for transferring the file from client to server or from the server to the client. The issues resolved by FTP are, like two systems between whom the file is being exchanged may use different file convention or different way to represent text and data, or a different directory structure. To resolve these issue FTP has a list of commands.

To copy a file from one host to another FTP establishes two connection one for data transfer and one for the control connection. FTP uses TCP service for transferring the file. TCP’s port 20 is used for data connection, and TCP’s port 21 is used for the control connection.

The control connection remains opened till the entire interactive session remains and closed when the session ends. While the control connection is opened the data connection open and closed each time, the file is transferred.

FTPThe control connection uses simple rules for the communication. On the other hand, the data connection is more complex as it uses different commands for the variety of data being transferred. Although the user is authenticated at the time of the connection establishment still, FTP is not secure as the password provided by the user is a plain text as well as the data is also transferred in plain text, which can be intercepted by the attacker. The solution to this is to add SSL(Secure Socket Layer).

Another way to transfer the file securely is to use an independent protocol sftp (secure file transfer protocol). The sftp is a part of SSH protocol.
https://techdifferences.com/difference-between-ftp-and-tftp.html

Backlinks: Teknik 1wiki:Linux:Generelt:Netværk - Server - Services:FTP-TFTP