What is an SFTP Server?

What is an SFTP Server

An SFTP (SSH File Transfer Protocol) server is a server that enables secure file transfer, remote file access, and file management over the internet using the SSH protocol. SFTP servers allow clients to securely transfer files between the client and the server using encryption and authentication mechanisms provided by SSH.

In short, SFTP servers provide a simple, secure, and reliable way to retrieve or upload files both automatically and manually.

For a deep dive into SFTP - look at What is SFTP 

Key functions of an SFTP Server

All SFTP servers provide the ability to authenticate as a user and send and receive files, but some extend the core functionality to provide a higher level of control, file management, access controls, and auditing. 

Here is some of the functionality you can expect from an SFTP server:

1. Security: SFTP servers ensure secure file transfers by encrypting data during transmission, preventing unauthorized access to sensitive information. They use SSH for authentication and encryption, providing robust security features.

2. Authentication: SFTP servers typically support various authentication methods, including password-based authentication, public key authentication, and certificate-based authentication. This allows clients to securely authenticate themselves to the server before accessing files.

3. File Management: SFTP servers provide functionality for managing files and directories on the server. Clients can upload, download, delete, rename, and manipulate files and directories on the server using SFTP commands or client applications.

4. Access Control: SFTP servers often include access control mechanisms to restrict access to files and directories based on user permissions and privileges. Administrators can define access policies to ensure that only authorized users can access specific files and directories.

5. Logging and Auditing: SFTP servers typically maintain logs of file transfer activities, user authentication events, and other relevant information for auditing and compliance purposes. This allows administrators to monitor and track file transfer activities on the server.

6. Compatibility: SFTP servers are compatible with a wide range of client applications and operating systems, making them versatile solutions for file transfer and remote file access in various environments.

How do I connect to an SFTP server?

To connect to an SFTP server, you need a client and some connection details. The client is the piece of software that you are using to upload and download files from the SFTP server with. 

For example:

• Putty
• Bitvise
• FileZilla
• Transmit
• Cyberduck

When connecting, you will need the following from your SFTP server provider:

• Hostname (IE: sftp.couchdrop.io)
• Port (port 22 most of the time)
• Username and Password
• SSH key (optional)

What are some common SFTP servers?

There are many SFTP servers available today. Most SFTP servers can be installed on a Linux or Windows server relatively easily. These servers then listen on port 22 for incoming connections and provide access to the underlying file system on the server.   

Some commonly installed servers:

• Bitwise SFTP Server
• VSFTPD
• OpenSSH
  

OpenSSH is installed and deployed on 95% of devices today - so it's normally the best choice.

Cloud-hosted SFTP Servers

The next generation of SFTP servers are cloud-hosted and provided as SaaS services. Cloud-hosted SFTP servers offer significant advantages over self-hosted versions and can simplify the process of deploying and managing an SFTP server. 

Some companies that provide cloud-hosted SFTP servers

• Couchdrop - (https://couchdrop.io)
• Files.com - (https://files.com)
• SFTP to Go - (https://sftptogo.com)

We are biased, but if you are looking for an SFTP server - check out Couchdrop, it really is the most comprehensive and affordable option out there.