An FTP site is a server that enables you to upload and download files through the File Transfer Protocol (FTP). Many people use FTP sites to move large files or numerous files from one computer system to another across a network.
For instance, web administrators commonly use FTP sites to upload web pages and associated files from a local computer to a web server. Some organizations also use FTP sites to carry out automated site-to-site file transfers, also known as server-to-server. In cases like this, each organization would have its own FTP site.
How does file transfer protocol or FTP work?
The FTP protocol operates on a client-server model, where each FTP client initiates a connection with an FTP server. FTP servers typically listen on port 21. So, when an FTP client attempts to connect to a server, it does so at that server port number.
Every FTP connection consists of a command channel and a data channel. The FTP channel is where commands and responses to those commands are sent. The data channel is where the actual files go.
When we say that an FTP client initiates a connection with an FTP server, this takes place over the command channel. So, before any data connection can be established and any file transfer can ever happen, a command channel connection has to be established.
FTP transfers are carried out in either active mode or passive mode. In active mode, the FTP server initiates the data channel connection to the FTP client. In passive mode, the client initiates the data channel connection to the server. It’s important to understand the differences between active and passive FTP because you need to consider these when configuring your firewalls.
The FTP protocol runs on the Internet/Transmission Control Protocol (TCP/IP). TCP/IP provides reliable, connection-oriented communication. Thus, data packets are delivered in order and without errors. TCP/IP helps ensure that FTP carries out file transfers with minimal risk of data loss or corruption.
Every FTP file transfer involves two endpoints: an FTP client and an FTP server. Let’s discuss these two endpoints next.
How FTP servers work
An FTP server or FTP site provides file transfer services to FTP clients. A single FTP server, also called an FTP host, can simultaneously facilitate the transfer of files for multiple FTP clients. Users can use the server to share files with other users. The server can accept file transfer uploads from clients, store the uploaded files and make the files available for download.
While FTP servers usually listen for FTP client connection requests on port 21, you can use other port numbers. For instance, some admins configure their server to listen on port 990, 2121 or 2120. While using non-standard FTP ports is acceptable, ensure all your users are aware of the port number. Otherwise, they’ll have trouble connecting to your FTP site.
There are various FTP servers in the market. Some are proprietary, while others are open source. Some operating systems also come with a built-in FTP server upon installation. Linux and Windows Server, for instance, have an FTP server included by default.
The best FTP sites aren’t plain FTP servers, though. Rather, they’re multi-protocol managed file transfer (MFT) servers that support FTP and several other file transfer protocols. MFT servers like JSCAPE MFT Server by Redwood come with many security features that enable you to protect your FTP file transfers. They also have automation features that make implementing site-to-site FTP transfers almost effortless. Want a closer look? Request a product demo to see our secure automation features at work.
How to use an FTP client?
An FTP client is a software application that users use to initiate a connection with an FTP server or site and to upload and download files with that server. A user would typically enter the site’s IP address or hostname along with the port number to connect to an FTP site using an FTP client.
Unless the user is using anonymous FTP, the user would also have to enter its user account login credentials before it would be granted access permissions by the FTP server. Normally, these credentials would be the user’s username and password.
Most FTP clients, such as FileZilla and WinSCP, are standalone applications installed on your laptop or desktop. However, some clients, such as the Cerberus web client by Redwood, run on web browsers. The main advantage of browser-based clients is that users don’t have to install them.
What server operating system is best suited for an FTP site?
The ideal server operating system for an FTP site often depends on your organization's specific needs. For instance, you’ll need to factor in your specific requirements for security, ease of use and compatibility with existing systems. Most of our customers use Linux and Windows for their FTP servers. Let’s look at some of the pros and cons of using these operating systems.
Pros and cons of using Microsoft Windows for your FTP site
One of the biggest advantages of using Windows Server for an FTP site is the operating system’s ubiquity. Because Windows is so common, you can easily find people who can deploy, manage and maintain your FTP site. If you only need an FTP server, you can use Windows Server Internet Information Services (IIS) built-in FTP server. The popularity of Windows also means your FTP server will be compatible with other Windows-based systems in your IT infrastructure. For instance, you can easily integrate it with Active Directory to centralize user authentication.
On the flip side, since Windows is so widely used, cybercriminals often target it. For instance, there is more malware for Windows systems than other operating systems. Also, since Windows Server is proprietary, you’ll have to spend more on licensing costs than on, say, a free Linux distribution.
Pros and cons of using Linux for your FTP site
Many Linux distributions and the FTP servers with them offer free licensing. So, if you have IT staff skilled in Linux, you can bring down your upfront costs. Furthermore, all Linux distributions are open source. This gives you greater flexibility and control should you wish to customize your FTP infrastructure.
While popular Linux distributions are backed by vibrant communities, less popular ones can leave you high and dry if you need technical assistance. For instance, if you encounter issues with your FTP server or want to equip it with security functions, you’ll struggle to find help.
Advantages of using a platform-independent FTP server
While Windows and Linux FTP site deployments are extremely popular, some businesses also use other operating systems. For instance, many of our customers also use UNIX and some even use macOS. Unless your company is deeply entrenched in a particular OS ecosystem, choosing an FTP solution that can run on any operating system may be best.
A platform-independent file transfer solution like JSCAPE MFT Server can seamlessly integrate with any OS. This flexibility lets you choose the best deployment for any specific use case. Not only that, if your deployment requirements change later on, you can easily migrate from one platform to another.
Sample use case: Leveraging a platform-independent file transfer solution for building out FTP sites
A global retailer in multiple countries and regions wanted to establish a company-wide infrastructure for facilitating FTP file exchanges between its headquarters and regional offices. These files included product catalogs, sales reports, marketing materials, inventory data, etc.
Incidentally, the retailer’s offices had their own OS preferences. This was due to regional preferences, legacy systems, local IT infrastructure and specific business requirements. Most of the company’s offices in Europe and Asia used UNIX and Linux, while most offices in the United States used Windows.
By leveraging a platform-independent file transfer solution, the retailer was able to build out its network of FTP sites while allowing its regional offices to work with their preferred OS. Since the regional offices didn’t have to adopt an unfamiliar OS, the implementation process was quick, seamless and cost-effective.
Are FTP sites still suitable for business use?
FTP sites used to be one of the most—if not THE most—widely used solutions for file sharing and transferring files across the internet. Today, however, businesses have to consider not only the speed and efficiency of a file transfer solution but also the level of security that the solution provides. Unfortunately, traditional FTP sites fail to meet that second consideration.
FTP sites that use plain FTP lack encryption, strong authentication and other security functions needed to protect personal information and other sensitive data often present in today’s file transfer workflows. These security functions aren’t just nice-to-haves. In many cases, they’re mandated by law or by regulatory bodies. In the US, for instance, FTP can’t meet the regulatory requirements of the Healthcare Insurance Portability and Accountability Act (HIPAA) or the Payment Card Industry Data Security Standard (PCI DSS).
To meet stringent regulatory requirements, businesses are shifting to file transfer sites running on more secure file transfer protocols, such as SSH file transfer protocol (SFTP) or FTP-over-SSL/TLS (FTPS). These secure FTP alternatives already come with built-in encryption and data integrity mechanisms that greatly enhance the security of business file transfers.
SFTP, which derives its security features from the underlying Secure Shell (SSH) protocol, also has strong authentication. You can use password-based authentication alongside public key authentication to deliver a 2-factor authentication system. Two-factor authentication will make breaking into your user accounts more difficult for a threat actor.
Although not as commonly used as SFTP’s key-based authentication, FTPS offers a similar authentication method. This method uses X.509 digital certificates and is called client certificate authentication. As with its encryption and data integrity functions, FTPS gets these capabilities from the Secure Sockets Layer/ Transport Layer Security (SSL/TLS) protocol.
If you’re wondering why SSL/TLS sounds familiar, it’s the same cryptographic protocol used to secure the Hypertext Transfer Protocol (HTTP). HTTP secured by SSL/TLS is called HTTPS. It’s the protocol used by popular web browsers like Chrome, Firefox, Edge and Safari to connect with modern websites.
Sample use case: Leveraging a multi-protocol solution for building out a versatile file transfer infrastructure
The global retailer discussed earlier wanted to exchange files with suppliers and other trading partners. While a few of their trading partners also used FTP, the rest had already shifted to secure file transfer protocols like SFTP and FTPS. Other trading partners even preferred Electronic Data Interchange (EDI)—aware protocols like Applicability Statement 2 (AS2).
Fortunately, the platform-independent solution the retailer was already using also happened to support multiple file transfer protocols. This enabled the retailer to meet their trading partners’ disparate protocol requirements without deploying additional file transfer solutions.
Test drive JSCAPE
There was a time when FTP sites were the logical choice for transferring files through a network. Not anymore. Traditional FTP sites are no longer enough to meet modern enterprises' advanced data transfer requirements. A secure, platform-independent, multi-protocol file transfer solution will put you in the best position to handle whatever file transfer requirements your trading partners may have. Test drive JSCAPE with a free trial to see how our features work together to support your file transfer needs.