Introduction

Ever wondered how big files travel across the internet? Long before we had slick cloud drives, we had FTP. FTP stands for File Transfer Protocol, and it’s a true classic of the digital world. Its only job is to move data from a server to your computer, or vice versa, using a network like the internet.

So, how does this old-school tech work? FTP uses a unique two-channel system, one for sending commands and another for the actual data. This client-server design is what made it so reliable for decades. While it might sound dated, FTP still plays a vital role in web development and data management. In this blog, we will discuss what FTP in computer networks is, its functioning, and practical examples where we will look into how you can transfer files using FTP. We will also discuss different types of FTP and modern File transfer alternatives to FTP.

What is FTP Protocol in Computer Networks?

FTP in computer networks stands for File Transfer Protocol. It is a standard communication protocol that is used to transfer files between computers over a network. FTP enables easy downloading, uploading, and managing of files, serving as a foundational tool for computer networks. It is widely used in the application layer of the OSI Model.

The FTP Protocol stands out from other protocols like HTTP, which can also transfer files between computers but are less specialized for this purpose. Computers connected through FTP can have different operating systems, directory structures, and character sets, but FTP has the tendency to handle these differences and make file transfers smooth and reliable.

It supports transferring files in formats like ASCII, EBCDIC, and binary (image). By default, ASCII is used, where each character is encoded in NVT ASCII, but the receiving system must be prepared to accept files in ASCII or EBCDIC modes. For binary files, FTP uses the image format as the default. To better understand the FTP Protocol, the CCNA Course will be helpful.

It is widely used for transferring web pages, software updates, and other data over the Internet. It can also be used for downloading files to computer from other servers.

History of FTP in Computer Networks

FTP has been around since the early days of the internet. It first came into existence in the early 1970s, initially developed for simple file transfers in academic and research settings. It has evolved over the decade to meet modern requirements.

1971: FTP was introduced with its first specification (RFC 114) by Abhay Bhushan, intended to allow file sharing on the ARPANET, the precursor of the Internet.

1985: The protocol was officially standardized with RFC 959. This revision became the standard guide, and it was widely used in various systems.

1990s: With the spread of the public Internet, the security vulnerability of FTP (transmission of data in clear text) became an issue. This prompted the creation of secure FTP equivalents, such as FTPS and SFTP.

Why is FTP important in networking?

While moving data between systems is very easy and not complicated, there are situations when it can go wrong. For instance:

• The file conventions between two systems could be different.
• Text and data may be represented differently by two separate systems.
• Separate directory structures could exist on two separate systems.

These issues are solved by the FTP protocol by creating two connections between hosts. Data transfer takes place over one connection, and the control connection occurs over a different connection.

So, FTP is widely used for transferring large files, maintaining websites, and sharing data across various devices. Businesses rely on it for seamless data exchange between servers and clients. Many organizations use it for backup solutions, collaborative projects, and large-scale file distribution. Therefore, it remains a trusted tool for industries handling significant data volumes.

How FTP Protocol works?

FTP in computer networks operates on a client-server model. The client requests to access the file stored on the server, and the server responds to the client’s request and sends the respective file. The client and the server communicate using two types of connections. These are –

1. Control connection
2. Data connection

Control Connection

The client and server communicate to send and receive commands through the control connection. FTP uses a control connection to transmit information such as user name, password, remote directory change commands, file retrieval, storage instructions, etc. It is initiated via port 21.

Data Connection

The data connection allows the transfer of file data between the client and server. It is initiated via port 20. FTP works via two different modes. These are:

1. Active Mode: When a client starts a session through a command channel, the server initiates a data connection and begins exchanging information with the client.

1. Passive Mode: The server sends the client the necessary information to initiate a data channel through the command channel. To avoid being blocked by firewalls and NAT routers, the client always uses passive mode while making connections.

A typical FTP protocol works as:

• The client establishes a control connection to the server using TCP port 21.
• The client sends a username and password to the server.
• The client sends commands to navigate to the desired directory on the server.
• The client requests a data connection mode (active or passive) from the server.
• The client and the server establish a data connection using TCP port 20 (active mode) or a random port (passive mode).
• The client sends commands to transfer files to or from the server over the data connection.
• The client closes the data connection after the file transfer is complete.
• The client sends a command to terminate the control connection.

Purpose of File Transfer Protocol in computer networks

FTP is designed to transfer files over networks with different operating systems, file systems, or architectures. Users using FTP in computer networks are able to access and alter files located on distant computers without worrying about the specifics of how the data are being moved or stored.

FTP Protocol is used for a variety of purposes, some of these are:

• Backup: It can be used to back up files from one computer to another.
• Software distribution: It can be used to download software updates or patches from a vendor’s server.
• Access and Data loading: FTP is frequently utilized to gain access to shared web hosting and cloud services, aiming to transfer data onto a server located remotely.

Types of FTP Protocol

There are several varieties of file transfer protocols available. Some of these are:

Secure FTP (SFTP)

SFTP stands for The SSH File Transfer Protocol. SFTP is a layer above SSH that provides all the security and authentication capabilities of SSH. This protocol is rapidly replacing FTP/S and has already overtaken legacy FTP. It provides the full range of features available via these protocols with high reliability and higher levels of security.

It shares nothing with traditional File Trasnfer Protocol except the purpose – moving files.

Here’s how SFTP differs:

Single Connection Design

• Uses one port (22) for everything

• Commands and data share the same channel

• Firewalls handle it better

• NAT traversal works smoothly

Protocol Integration

SFTP operates as an SSH subsystem. When you connect:

1. SSH handshake occurs first

2. Client and server negotiate encryption

3. Authentication happens (password or key)

4. SFTP subsystem activates

5. File operations begin

This integration means SFTP gets SSH improvements automatically. New encryption algorithms. Better key exchange methods. Enhanced authentication options.

Trivial FTP (TFTP)

TFTP is a simplified version of FTP that uses UDP instead of TCP for data transfer. Not all programs can use TCP because of its complexity and the features they don’t require. Regarding client-server interactions, TFTP’s simple structure and low cost make it suitable. TFTP is limited to File Transfer only and does not permit authentications.

TFTP is mainly used for bootstrapping network devices or transferring small files.

File Transfer Protocol Secure (FTPS)

File Transfer Protocol Secure (FTPS) is the secured variant of FTP, similar to Hypertext Transfer Protocol Secure. Transport Layer Security (TLS) and secure socket layer (SSL) safeguard these protocols. Using FTPS, companies may establish encrypted connections with their clients, partners, and end-users.

FTPS operates in two distinct modes:

Implicit FTPS

• Uses port 990 by default

• Assumes encryption from the start

• Client connects expecting SSL/TLS immediately

• No negotiation occurs

• Older method, less common today

Explicit FTPS

• Uses standard FTP port 21

• Starts as plain FTP connection

• Client requests security with “AUTH TLS” command

• Server agrees and switches to encrypted mode

• More flexible and widely supported

Note: FTPS requires SSL/TLS certificates. Organizations must purchase or generate these certificates. They expire and need renewal. This adds management overhead compared to basic FTP.

Hypertext Transfer Protocol (HTTP)

Hypertext Transfer Protocol, or HTTP, is a popular way to exchange data in the corporate world. This protocol is very easy to implement for server-to-client and client-to-client file transfers. The HTTP protocol is vulnerable to firewall-related challenges. However, compared to FTP, it is fundamentally insecure and lacks the ability to ensure data security and regulatory compliance. This protocol is implemented in situations where security concerns are not a factor.

FTP over Explicit SSL/TLS (FTPES)

FTPES isn’t a new protocol. It’s traditional FTP with security added. FTPES maintains FTP’s core behavior while wrapping communications in SSL/TLS encryption. It protects what FTP left exposed.

Here’s how FTPES differs:

Dual Mode Design

• Starts as regular FTP on port 21

• Upgrades to secure mode on request

• Maintains separate control and data channels

• Supports both encrypted and unencrypted sessions

Backward Compatibility

• Works with standard FTP servers

• Falls back to plain FTP if needed

• Clients choose security leve

• Legacy systems stay functional

Choosing the Right Protocol: FTP vs. FTPS vs. SFTP

File transfer protocols evolved to meet security demands. Understanding their differences helps you pick the right tool. Each protocol serves specific needs. Let’s examine how they work and when to use them.

Feature	FTP	FTPS	SFTP
Encryption	None	SSL/TLS	SSH
Default Port	21 (control), 20 (data)	990 (implicit), 21 (explicit)	22
Authentication	Username/password (plaintext)	Username/password (encrypted)	Username/password, SSH keys
Data Channel	Separate connection	Separate connection (encrypted)	Single connection
Firewall Friendly	No	No	Yes
Protocol Base	TCP	TCP with SSL/TLS	SSH
Year Introduced	1971	1997	1997
Speed	Fastest	Slower than FTP	Moderate
Certificate Required	No	Yes	No

Choose FTP only for:

• Public file distribution

• Legacy system compatibility

• Internal networks with zero sensitive data

Choose FTPS when:

• Upgrading existing FTP infrastructure

• Compliance requires encryption

• Trading partners mandate FTPS

• Certificate infrastructure exists

Choose SFTP for:

• New implementations

• Automated file transfers

• Cloud deployments

• Maximum security requirements

• Simplified firewall management

File Transfer Protocol Commands

Here are the File Transfer Protocol Commands –

FTP Commands	Description
!	It allows shifting between operating systems and FTP.
?	It allows to print information about FTP commands.
append	It allows joining two files together.
ascii	It allows converting the file share mode to ASCII and is the default mode for many FTP programs.
binary	It fixes file share mode to binary.
bell	This command is used to alert by bell sound when any command is executed.
bye	It allows to exit and terminate the FTP session.
cd	It allows modification of the remote system’s directory.
close	It allows terminating FTP connections to remote systems.
dir	It allows to receive a list of contents in a remote directory.
delete	It allows deleting a file from the currently open remote directory.
debug	It allows activating and turning off debugging mode, and this command does not require a remote system connection.
disconnect	It allows terminating the FTP session.
FTP	It allows access to the FTP interpreter.
get	It allows to creation of duplicate data (one file) from the server to the client device.
hash	It allows a client to request a cryptographic hash of a file from the server-side FTP process.
help	It allows local help information to be presented. This command does not need a remote system connection.
lcd	It allows changes to be made to directories on your local system.
literal	It shares the argument with the remote system.
ls	It allows to present a list of names of files in the current remote directory.
mdelete	It allows deleting most files at once.
mdir	It allows listing the contents of multiple remote directories.
mget	It allows duplicating multiple data files from a remote computer to a local computer.
mkdir	It allows the creation of a new directory within an existing remote directory.
mls	This command shows a list of file names in multiple server directories.
mput	It allows multiple files to be duplicated from a user device to a server device.
open	This command allows the creation of a link with another computer system.
put	This command allows to duplication of a file from a user device to a server device.
pwd	It allows finding out the path name of the local directory of the remote system.
quit	It allows the FTP session to be terminated (like bye).
quote	It shares the argument with the remote system.
recv	It allows the recovery of files from a remote machine.
remotehelp	It allows for presenting remote system information.
rename	This command allows changing the name of a system file.
rmdir	It allows removing a directory from a local remote directory.
send	This command allows sending files.
status	This command allows to show the current state of the system.
type	It allows specifying the file share type.
user	This command shares the details of the new user.
verbose	It allows to turn verbose on/off.

These are the commands of File Transfer Protocol.

FTP Clients

An FTP client is a software that allows sharing of files by creating a connection between both the host computer and the remote server through the server’s domain, IP address, username and password. It enables the transmission of data and files in both directions between two computers that have a TCP network or Internet connection. It works on a client/server model where the host computer acts as the client and the remote FTP server acts as the central server.

Below are some of the following FTP clients:

• FileZilla: FileZilla is an open-source and free FTP client. It provides support for FTP, FTPS, and SFTP on Windows, macOS, and Linux.
• Transmit: Transmit is a macOS FTP client, and it provides support for FTP and SSH.
• WinSCP: It is a free SSH file share protocol available for Windows FTP clients that provides support for FTP, SSH, and SFTP.
• WS_FTP: It is another FTP client for Windows, and it provides support for SSH.

How to Transfer Files Using FTP

There are three ways via which you can transfer files using FTP. These are:

• Using an FTP Client

• Using the Command Line

• Using a Web Browser

Let us understand each in detail.

Using an FTP Client (e.g., FileZilla, WinSCP)

Below, we have discussed how you can use FileZilla to transfer your files with ease.

FTP clients make file transfers easy. FileZilla is free and works on most systems. Here’s how to use it:

1. Download and install FileZilla (FileZilla – The free FTP solution) from the official website. Run the installer and follow the prompts.

2. Open FileZilla and look at the top toolbar. You’ll see fields for Host, Username, Password, and Port.

3. Enter your server details:

• Host: Type your server address (like ftp.example.com)

• Username: Enter your FTP username

• Password: Type your FTP password

• Port: Use 21 for standard FTP (or leave blank)

4. Click “Quickconnect” to establish the connection. A successful connection shows your local files on the left and server files on the right.

5. Navigate directories by double-clicking folders. The left panel shows your computer. The right panel shows the server.

6. Upload files by dragging them from left to right. Download by dragging from right to left.

7. Monitor transfers in the bottom panel. Green means success. Red indicates errors.

8. Disconnect when done by clicking the disconnect button or closing FileZilla.

Using the Command Line

Command line FTP works on any system. It’s fast once you know the commands. The process differs slightly between operating systems.

For Windows:

1. Open Command Prompt by pressing Windows+R, typing “cmd”, and hitting Enter.

2. Type ftp and press Enter to start the FTP program.

3. Connect to your server with: open ftp.example.com

4. Enter credentials when prompted. Type your username, press Enter, then type your password.

5. List files using dir or ls commands.

6. Change directories with cd foldername to navigate.

7. Download files using: get filename.txt

8. Upload files using: put localfile.txt

9. Exit by typing bye or quit.

For macOS/Linux:

1. Open Terminal from Applications or by pressing Ctrl+Alt+T.

2. Connect directly with: ftp ftp.example.com

3. Login with your username and password when asked.

4. Navigate using standard Unix commands:

• ls to list files

• cd to change directories

• pwd to show current directory

5. Transfer files:

• get remotefile.txt downloads to your current local directory

• put localfile.txt uploads from your current local directory

6. Use binary mode for non-text files: Type binary before transferring images or programs.

7. Close connection with exit or quit.

Using a Web Browser

Browsers offer basic FTP access. This method works for quick downloads but has limits.

1. Open your web browser (Chrome, Firefox, Safari, or Edge).

2. Type the FTP address in the address bar: ftp://ftp.example.com

3. Enter credentials in the popup window. Some servers allow anonymous access.

4. Browse folders by clicking on them. The browser displays files like a basic directory listing.

5. Download files by clicking on them. Files will be downloaded to your default download folder.

Security note: Standard FTP sends data unencrypted. For sensitive files, use SFTP or FTPS instead. These protocols add encryption to protect your data during transfer.

Advantages of File Transfer Protocol

FTP protocol has several advantages as a file transfer protocol, such as:

• Transfer large files: The feature of FTP protocol to transmit a vast number of files, regardless of their size, is its most useful feature. When you need to transfer terabytes of data all at once, FTP can manage the task both effortlessly and quickly, avoiding inefficiencies and lost time in the process.
• Transfer multiple directories at once: Enhance your workflow efficiency by transmitting multiple directories simultaneously without the need for frequent monitoring of the transfer progress. Additionally, you can transmit individual files or directories as needed. It is possible to continue working while the transfers occur in the background.
• Control over your transfers: It allows the user to resume a disrupted transfer in case of a lost connection without initiating the process. Certain FTP clients offer the capability to schedule data transfers, allowing users to determine the degree of automation they desire.
• WordPress management: FTP is also essential for working with WordPress sites because it establishes a direct link to the site’s files, you can perform things like installing and deactivating WordPress plugins and themes by hand or make modifications to the core WordPress files. Likewise, FTP may be used to identify and fix typical website problems, including incompatibility with external resources, conflicts between themes, and internal server failures.

Disadvantages of FTP Protocol

There are several disadvantages of using File Transfer Protocol. Here are some of the key drawbacks:

• Lack of Security: It transfers data in plain text, making it vulnerable to interception and unauthorized access.
• Firewall and NAT Issues: FTP’s separate control and data connections can cause problems when passing through firewalls and NAT devices.
• Lack of Error Checking: It lacks built-in error checking and resuming capabilities, requiring entire file transfers to restart if interrupted.
• Limited Scalability: It struggles to handle high loads and large numbers of concurrent connections efficiently.
• Lack of Standardization: FTP Protocol variations and extensions can cause compatibility issues between different clients and servers.

Why Standard FTP Is No Longer Secure? 

FTP served its purpose well for decades. But the internet has changed. What worked in 1971 fails to protect data today. Understanding these weaknesses helps you make better choices for file transfers. 

The 1970s Design Problem

FTP emerged in 1971 at MIT. Back then, the internet was ARPANET – a small network of trusted institutions. Only universities and government agencies had access. Security wasn’t the priority. Speed and functionality were.

Today’s internet connects billions of devices. Hackers, criminals, and state actors prowl networks constantly. The trust model from 1971 doesn’t matches our reality. FTP’s core design never adapted to these threats.

The Plaintext Problem

FTP’s biggest flaw is simple: everything travels as readable text. When you connect to an FTP server, your username flows across the network like a postcard. Anyone watching can read it. Your password follows the same path – completely exposed.

Here’s what happens during a typical FTP session:

1. You type your username. FTP sends “USER john.smith” across the network.

2. You enter your password. FTP sends “PASS MyPassword123” in plain view.

3. You transfer a file. Every byte moves without encryption.

Network administrators can see these credentials. So can anyone with packet-sniffing software. Free tools like Wireshark make this possible.

Common Attack Methods

FTP is not secure and is susceptible to various attacks. Below, we have discussed some of these attacks. 

• Packet Sniffing: Hackers use tools like Wireshark to capture FTP traffic. On public Wi-Fi, stealing passwords takes minutes. Free software makes this trivial for beginners.

• Spoofing Attacks: Attackers create fake FTP servers. They redirect your connection through DNS poisoning. You enter credentials, thinking it’s your real server. Hackers capture everything.

Man-in-the-Middle Attacks: Attackers position themselves between you and your server. They intercept all traffic. Files can be modified during transfer. Neither side detects the intrusion.

Modern File Transfer Alternatives for 2025

The file transfer landscape has transformed. While FTP served businesses for decades, modern demands require modern solutions. Today’s organizations need more than basic file movement. They need compliance tracking, automation, and seamless integration. Let’s explore the alternatives reshaping how businesses share data.

Managed File Transfer (MFT) Solutions

MFT platforms revolutionize the enterprise file movement. Think of MFT as file transfer with intelligence. These systems don’t just move files. They orchestrate, monitor, and secure the entire process.

Core MFT Capabilities:

Centralized Control

• Single dashboard for all transfers

• Real-time monitoring across systems

• Unified user management

• Policy enforcement from one location

Advanced Security

• End-to-end encryption by default

• Data loss prevention features

• Automatic PGP encryption

• Secure file storage and retention

Automation Engine

• Schedule transfers without human intervention

• Trigger workflows based on file arrival

• Integrate with business applications

• Handle errors and retries automatically

Compliance Features

• Detailed audit logs for every action

• Tamper-proof transaction records

• Built-in reporting for regulations

• Data retention policy enforcement

MFT systems transform file transfers into business processes. A bank can automatically collect transaction files from branches. The system validates each file. It encrypts sensitive data. It routes files to processing systems. Audit logs capture every step.

Cloud Storage Platforms

Cloud platforms changed how organizations think about files. No more FTP servers in closets. No more VPN configurations. Just simple, secure sharing through familiar interfaces.

Business-Grade Cloud Solutions Include:

Enterprise File Sync and Share

• Dropbox Business

• Box for Business

• Google Workspace

• Microsoft OneDrive for Business

These platforms offer more than storage. They provide:

• Version control for all files

• Real-time collaboration features

• Mobile access from any device

• Integration with productivity tools

• Advanced sharing permissions

• Activity tracking and reporting

API-Driven Platforms

Modern cloud services introduce robust APIs. Developers integrate file operations directly into applications. No separate transfer protocols needed. The cloud service handles security, scaling, and reliability.

Frequently Asked Questions

Q1. How Does FTP Work?

With FTP, you may send data over the Internet. The use of FTP requires access to the Internet. When a file is downloaded, it is sent from a server to the receiving device, but when it is uploaded, it is sent from the receiving device to the server.

Q2. Does FTP Use TCP or UDP?

For transport purposes, FTP only relies on the usage of the transmission control protocol (TCP) rather than the user datagram protocol (UDP).

Q3. What is FTP used for?

File Transfer Protocol (FTP) allows data exchange between computers connected through a Transmission Control Protocol (TCP) network, such as the Internet.

Q4. What is FTP in Linux?

The establishment of an FTP connection between two machines in Linux can be achieved through the utilization of the command “ftp.”

Conclusion

FTP in computer networks is a prominent protocol for transferring files over a network. It operates on the client-server model and uses two separate channels for communication: a control channel and a data channel. It has stood the test of time as a reliable tool for file transfers in computer networks. Understanding how it works, why it is important can help you make informed decision on whether use it or not.