FTP is a group of standard protocols that allow interconnected or networked computers to transfer files and communicate over the internet. FTP server is a computer that offers access services and file storage on the internet, it handles all the data transmission between networked computers. FTP server waits for the client to connect to it and it uses the FTP protocol commands to do all the tasks such as uploading, listing directories, or downloading.
FTP is based on client/server architecture. A user is a client that supports FTP protocol through which it can connect to an FTP server on a remote host. The client can issue commands so that the remote server can execute them, after executing the commands the host server returns the results of execution to the client. For example, the user supplies a command and asks the server to forward the file. The server will reply to the request and will send the file to the client. After that, the user can put the file in the working directory. These types of processes are carried out by the FTP servers.
Working of FTP Server
FTP service is a TCP-based protocol, i.e., it is a file transfer protocol. By default, it uses port 20 (data port) and port 21 (command port). A user sends a service request to the server in the network. After that, the request is received by the server, which replies to the user’s request and supplies the user with the requested file transfer service. FTP uses a continuous connection communication method to keep the long control connections running. Based upon the type of mode of the connection the number of data ports can differ.
Types of Connections in FTP
Generally, in a session where transfer of file takes place, the FTP uses two separate types of connections i.e., Data connection and Control connection.
- Control Connection: The control connection is used for sending commands between the user and server. It is the primary connection and it uses port 21.
- Data Connection: Data connection is used only for transferring data. It establishes a connection between the DTP(Data Transfer Process) of the client and server, and it uses port 20.
Types of Connection Modes
The FTP server can support Active mode, Passive mode, or both modes.
- Active mode: In this mode, the user opens a port and listens while the server is actively-connected to it. Here the client can connect from any random port.
- Passive mode: In this mode, the server opens a port and, it passively listens to it and, the user also passively connects to it. The passive mode is used as default as a safety measure. Passive mode can be used when the user can’t receive connections i.e., in cases where the connection is blocked by a firewall.
Functions of FTP Server
- Sending large files by email is typically difficult for organisations. Large files frequently cause hiccups in the file sharing process for businesses handling enormous volumes of data. Organisations can easily share huge files by using the FTP server.
- Ensuring a high level of security when transmitting sensitive data across the network is the main reason to use FTP servers. To offer even more protection, FTP servers now allow other secure file transfer protocols as FTP Secure (FTPS) and SSH File Transfer Protocol (SFTP). Effective end-to-end encryption is ensured by these protocols to protect files while they are in transit.
- FTP servers assist businesses in streamlining the file-sharing procedure to address issues with productivity. Instead of sharing one file at a time, users can communicate enormous amounts of data when they have the appropriate software programme in place. The time needed to find a file is reduced when files are centrally stored, and workflow disruptions are prevented by scheduling transfers.
- By offering intelligent access controls, FTP servers enable companies to have more control over the data they handle. Based on permissions, administrators can quickly decide who can modify, publish, download, or share files because each user needs a particular set of permissions to access different types of data.
- Following a disaster, an efficient FTP server makes sure that organisational files and data are not lost or corrupted. Proactively storing data at different locations for simple restoration when necessary is made easier with continuous and automatic backup.
Types of FTP Server
- FTP Secure (FTPS): This protocol guarantees a safe file transfer by enhancing security beyond that of standard FTP. During data transmission across the network, it offers an extra layer of encryption utilising the Secure Sockets Layer (SSL) or Transport Layer Security (TLS) protocols.
- SSH File Transfer Protocol: The Secure Shell (SSH) protocol’s secure file transfer subsystem is called the SSH File Transfer Protocol (SFTP). One popular technique for safely sending files over distant systems is SFTP. In SFTP, commands and data are sent over a single, secure SSH connection in specially designed binary packets that are encrypted.
Communication with FTP server:
A user can communicate with the FTP server by using the telnet program via port 21.
>telnet mkcbt.wrt.it 21
Trying 69.198.63.156…
Connected to mkcbt.wrt.it.
Escape character is ‘^]’.
220 ProFTPD server (EV) [69.198.63.156]
The next step is to supply the username and password.
>USER mkcbt
331 password requires for mkcbt.
>PASS [REDACTED]
230 user mkcbt logged in
>PASV
227 entering passive mode (69,198,63,156,116,239).
>telnet mkcbt.wrt.it 29819
Trying 69.198.63.156…
Connected to mkcbt.wrt.it
Escape character is ‘^]’.
>LIST
150 Opening BINARY mode data connection for file list.
226 Transfer complete
drwxrwx--- 2 mkcbt 2048 0 Nov 2 15:12.
drwxrwx--- 2 mkcbt 2048 0 Nov 2 15:12.
-rw-rw---- 2 mkcbt 2048 5 Nov 2 12:52. xp_gif
-rw-rw---- 2 mkcbt 2048 5 Nov 2 13:12. xc_txt
-rw-rw---- 2 mkcbt 2048 5 Nov 2 13:52. xpc_vid
-rw-rw---- 2 mkcbt 2048 5 Nov 2 14:27. gmarker
-rw-rw---- 2 mkcbt 2048 5 Nov 2 16:24. test
As can be seen above, the FTP server works when a client supplies the commands and then it delivers responses.
Commands used in FTP Server
- USER: Use a username to verify a user’s identity.
- PASS: Use a password to authenticate a user.
- CWD: Modify the current working directory
- PWD: Print the directory that is currently in use.
- LIST: Enumerate a directory’s contents.
- STOR: Stores a file on the server (uploads it).
- DELE: Clear out a file from the server.
- RNFR: Rename the “from” file .
- SITE: Carry out commands exclusive to a server.
- HELP: Find out more about FTP commands.
- QUIT: Remove your connection to the FTP server.
Advantages of FTP Server
- FTP servers offer a level of security.
- FTP server gives the user a level of control.
- FTP server allows a user to send big files at once.
- It improves workflow.
- It allows data recovery.
- It has a resumption facility i.e., it allows the transfer of files even after a break-in connection occurs.
Disadvantages of FTP Server
- All the files, passwords, and usernames are sent in unencrypted text.
- TLS 1.2 might not work over HTTPS as it is not always supported.
- It is possible to spoof servers to send data to an unpremeditated computer or on a random port.
Comparison of FTP Servers and Files Services
Large file sizes are no match for an FTP server’s capacity to handle them and enable safe, rapid transfers. Because FTP servers make it simple to upload, download, and manage data from a distance, they are the best choice in situations where file sharing and teamwork are the main objectives. Furthermore, FTP servers have sophisticated security features like SFTP and FTPS encryption protocols, guaranteeing the protection of your private information while it’s in transit.
The capabilities offered by File Services, however, go beyond simple file transfer. With cutting-edge features like file synchronisation, version control, access controls, and collaboration tools, they provide a centralised system for storing files. You can use File Services to track changes made to files, establish permissions for various individuals or groups, and construct an organised file hierarchy. It’s crucial to take your unique requirements and priorities into account when choosing between File Services and FTP servers. An FTP server would be a good option if effective file transfer and teamwork are your primary needs. File Services might be a better choice, though, if you require a more complete solution with file storage, organisation, and sophisticated collaboration tools.
The choice between File Services and FTP servers ultimately comes down to your organization’s size and makeup, the amount of data you need to handle, and the degree of control and protection you need. It is possible to make an informed choice and select the solution that best meets the requirements of your business by carefully weighing these considerations.
Frequently Asked Quetion on FTP server – FAQs
What is FTP Server?
FTP server is basically a computer that offers access services and file storage on the internet, it handles all the data transmission between networked computers.
How does FTP work?
Using the file transfer protocol (FTP), one can download, upload, and move files between computer systems and between locations on the Internet.
What is FTP authentication?
Users can utilise a digital certificate, a Kerberos service ticket, or their user ID and password to authenticate while connecting to the FTP server. If the administrator grants permission, a user may also connect anonymously. Refer to the FTP server configuration guidelines for anonymous FTP.
How can I set up an FTP server?
To access Internet Information Services (IIS) Manager, navigate to Start > Control Panel > Administrative Tools. Extend the local server after launching the IIS console. Select Add FTP Site with a right-click on the Sites menu. Enter the server’s IP address in the Binding and SSL Settings window.
What is SFTP?
The Secure File Transfer Protocol, or SFTP, is a secure file transfer protocol that offers a high level of security for file transfers both sending and receiving. It does this by using secure shell encryption.