FTP (File Transfer Protocol) is a standard network protocol used for transferring computer files between a client and server. It uses separate connections for control commands and data transfer, with port 21 for control and port 20 for data by default. Some key FTP commands include RETR (retrieve a file) and STOR (store a file). While convenient, FTP has security issues as it transmits passwords and file contents in plaintext.

1. FILE TRANSFER PROTOCOL(FTP)
BY: VARNIT
YADAV
B.Tech(C.S.)
U.I.E.T.
B.B.A.U.

2. WHAT IS FTP?
The File Transfer Protocol (FTP) is a standard network
protocol used for the transfer of computer files from a
server to a client using the Client–server model on
a computer network.

3. HISTORY OF FTP SERVER
• Initially written by Abhay Bhushan.
• Until 1980, FTP ran on NCP.
• The protocol was later replaced by a TCP/IP
version, RFC 765 and RFC 959.

4. Basic model of FTP

5. Components of client
• User interface
• Client control process
• Client data transfer process
Components of server
• Server control process
• Server data transfer
process

6. TWO CONNECTIONS
• Control Connection
• Data Connection

7. CONTROL CONNECTION
• Port 21 is used for the control connection.
• Uses the NVT ASCII character set as used by TELNET.
• Communication is achieved through commands and
responses.

8. SOME FTP COMMANDS

9. SOME RESPONSES IN FTP

11. DATA CONNECTION
• Port 20 at the server site is used for the data connection.
• The client issues a passive open using an ephemeral port.
• Using the PORT command the client sends this port
number to the server.
• The server receives the port number and issues an active
open using port 20.

13. COMMUNICATION OVER DATA CONNECTION
The heterogeneity problem is resolved by defining three
attributes of communication: file type, data structure, and
transmission mode.

14. FILE TYPE
• ASCII file
•EBCDIC file
•Image file

15. DATA STRUCTURE
• File structure
• Record structure
• Page Structure

16. TRANSMISSION MODE
• Stream mode
• Block mode
• Compressed mode

17. FILE TRANSFER
•Retrieving a file (server to client)
• Storing a file (client to server)
• Directory listing (server to client)

18. SECURITY FOR FTP
• FTP requires a password, it is sent in plaintext,
which means it can be intercepted and used by an
attacker.
• The data transfer is in plaintext, which is
insecure.
• To be secure one can add a Secure Socket
Layer(SSL) between the FTP application layer

19. THANK YOU