What Is FTP? FTP Clients and FTP Ports Explained

If you have ever downloaded a file from a website, the FTP is what allowed you to do so. Businesses and web developers use this popular protocol to securely upload and share large files with ease. In this article, we'll discuss the FTP meaning and basics, including what it's used for, how it works, and the FTP ports involved.

What does FTP stand for?

FTP stands for File Transfer Protocol. It's a shorter acronym for the standard communication protocol for sending files across the Internet.

What is FTP?

File Transfer Protocol (FTP) is a network protocol used to transfer files between computers over a TCP (Transmission Control Protocol) or UDP (User Datagram Protocol) connection, or, essentially, the Internet. Basically, it provides for a way for two computers connected to a server to transfer files. It originally served as a way to transfer files from physical device to physical device, but now it primarily operates through cloud servers.

There are two main uses for File Transfer Protocol: file sharing and web development. Businesses use File Transfer Protocol to easily transfer sensitive files between computers. Web developers use File Transfer Protocol to upload and download files to their websites' servers.

FIle transfer protocol (FTP) graphic illustration

File Transfer Protocol is capable of using TCP ports or UDP ports to establish data connections. Ports are crucial to the function of FTP, meaning if ports are not working properly, you need to use a port scanner to check their accessibility.

How does FTP work?

File Transfer Protocol is a client-server protocol that computers use to transfer files over a network. For two parties to share files using the protocol, the users need to utilize a web browser or FTP client to enter username and password credentials to the FTP server. Note that some servers lack password protection.

After establishing a connection, a complete data transfer requires two separate channels. The first channel, called the command channel, is used for the instructions and the response. The second channel is the data channel. This is where the transfer of files occurs.

The command channel uses TCP port 21, while the data channel uses TCP port 20.

Essentially, File Transfer Protocol works through these steps:

  1. The user logs in to or accesses an FTP server.
  2. The client then connects to and interacts with the server.
  3. The client can upload and download files on the server once the connection is established.

Active mode versus passive mode

Active mode is the traditional connection type. With active mode, the server dictates which port number to use. While in passive mode, the client can choose which port to use.

The reason there are two modes is because of firewalls, which can block certain port numbers. For example, say your firewall blocks port 20, which is the port used to transfer data. In this case, you could use passive mode to get around this block. With passive mode, your FTP client can change to use a different port for the client and server to transfer the data.

Uses of File Transfer Protocol

FTP, as established earlier, is primarily used for file sharing across networks. However, that isn't its only use. Other uses of File Transfer Protocol include:

  • Backup. Some organizations use FTP to secure data in remote servers. They use FTP to back up important data to different offsite servers, thus protecting the information should something happen to the primary servers.
  • Software distribution. Before cloud services and other protocols became integrated into modern systems, many software developers used FTP to transfer software and updates to users. Some developers still use this protocol for software distribution even in the age of more advanced technology.
  • Data migration. If an organization needs to move a mass amount of data from one system to another, FTP helps ensure that the transfer goes smoothly.
  • Website management. Website administrators use File Transfer Protocol to upload files or change data on their websites and servers. Because it has the ability to handle large files or multiple files at once, it's especially useful for extensive sites or sites that require a lot of monitoring and maintenance.
  • Network maintenance. Similarly, some network administrators find FTP useful when it comes to tasks like updating firmware on network devices.

Though File Transfer Protocol isn't the newest or even the most secure protocol available, many developers, administrators, and users find it helpful for a myriad of purposes.

How can I use File Transfer Protocol?

There are three main ways to use File Transfer Protocol: the command line, a web browser, and through a dedicated client software.

  1. Through the command line. The first, and oldest, method is to use a command line tool such as the Command prompt for Windows or Terminal for Mac or Linux. With this method, commands establish a connection to a File Transfer Protocol server port.
  2. Through a web browser. Another way is to use a web browser by typing "ftp.[web address].com" into the URL bar the same way you'd enter webpages. This method is helpful when attempting to upload or download large numbers of files.
  3. Through a dedicated client software. The last, and most common method, is to use a dedicated FTP client software. These are more reliable, faster, and more user-friendly than the other two methods. Popular free FTP clients providing FTP services include Cyberduck and FileZilla.

How to use an FTP client

To connect to an FTP server using an FTP client, you typically need to enter a username and password, host or server name, and FTP port number (data port 21). Once connected, File Transfer Protocol client interfaces usually allow you to drag and drop files to and from your hard drive into the server.

What is Secure File Transfer Protocol?

Traditional File Transfer Protocol operates with password protection. However, connection security ends there. The information sent lacks encryption over FTP, leaving it vulnerable to interception.

Creators of the protocol did not originally intend it to provide a secure channel to send and receive data. Thus, if a hacker were to intercept your transmission, they would be able to read everything with ease. This is also the case with Trivial File Transfer Protocol (TFTP), which operates faster than traditional FTP to transfer information.

Secure File Transfer Protocol is the File Transfer Protocol, but with additional protective measures added on. It uses SSH, or secure shell, security and encryption to block port scanning and password sniffing, as detailed above. It necessitates server authentication as well, which keeps hackers from intercepting information during transfers.

To encrypt the data you send, you should use TCP port 22 instead of TCP port 21 when establishing the connection. This will establish a Secure File Transfer Protocol connection. Encrypting your files will greatly reduce the chance of hackers stealing your personal information.

Frequently asked questions

Is FTP still being used?

Yes, many still use File Transfer Protocol today. Though it's not used as commonly as it was and some organizations are seeking a replacement, the protocol is still the standard for most.

What port is FTP?

FTP traditionally runs on port 21 and port 20 as the command port and the data port, respectively.

What does FTP mean?

FTP means File Transfer Protocol.

Is FTP a security risk?

On its own, yes, FTP can potentially be a security risk. File Transfer Protocol utilizes password protection, but it doesn't offer any additional security measures. Secure File Transfer Protocol, however, uses SSH to protect and encrypt your connection. If you're worried about the security of File Transfer Protocol, use Secure File Transfer Protocol.