Today we are going to discuss about FTP (File Transfer Protocol) and its applications. FTP was designed using as much flexibility as possible. Therefore, it can be used over networks other than TCP/IP, as well as being designed to have the capacity with exchanging flies with a wide variety of machines.
Definition of File Transfer Protocol (FTP):
FTP stands for file transfer protocol where exchanging the files take place from one host to another connected to internet. FTP is a client-server based protocol with the help of FTP server you can upload or download the files. There are two types of connections in TCP/IP protocol
1. Data connection
2. Control connection
The commands which are used in the FTP protocol are
1. ASCII based, sent over control channel
2. USER username
3. PASS password
4. LIST (return list of files in current directory)
5. RETR filename (retrieves file)
6. STOR filename (stores file onto remote host)
FTP mainly used for transferring files between the computers and gives the ability of the website designers to upload files to their web server.
History of FTP:
FTP was written by Abhay Bhushan in 1971 and it was published as RFC 114. FTP is a system file transfer protocol originally described in RFC 959 in 1980 and has undergone several changes and improvements since then. Other specifications were also came like, RFC 1579 (February 1994) which is firewall friendly, RFC 2228 (June 1997) for security extension, RFC 2428 (September 1998) it add support to the IPV6 which defines new type of passive mode.
How FTP works?
The file transfer protocol was one of the first attempts to make a standard means of exchanging flies on a TCP/IP network. File transfer protocol can restrict unauthorised users to intervene in the company process. If you are running a company and looking for an efficient way to transfer files in addition with secure communication just sign up for a FTP hosting service. That service will provide you a network with a secured FTP server.
FTP hosting service is effective, unlike email where you send flies from person to person. FTP hosting permits you to upload documents of any size or kind they can be then downloaded by the receiver of the files.
Whenever you are building a website you have to learn how to use FTP. So, some of the ways to use FTP which are listed below
1. FTP account
2. Adding sites to your client
3. Changing files or directory permissions
4. Editing files
5. Creating new files
6. Batching file downloads and uploads
Therefore, some of the drawbacks of the FTP are:
1. It is not a secure protocol
2. Data which is transferred is not encrypted
3. FTP used on only limited basis
4. Data sent in clear text
There are two modes in FTP
1. Active mode
2. Passive mode
The active and passive modes are the two connections in FTP which communicate with each other.
1. Client connects to port 20 of the server from random port and tells the server which port it has open for data transfer.
2. Server connects from port 21 to the random port specified by the client.
In active mode client requests for the data connection and server initiates the data connection with the client and establishes the connection .
1. Client connects to port 21 of the server from random port and server then specifies what port it has opened for data transfer.
2. Client then connects from random port to the random port specified by the server.
In passive mode client initiates both command channel as well as data channel to the server.
Now from above info you know what is FTP and its function. If we miss something comment in the section below we will be happy to update it.