Which Protocols Are Used for File Sharing? A 2026 Guide to FTP, SFTP, SMB, and More

Key takeaways

• Remember the default ports: FTP uses 21 and 20, SFTP uses 22 over SSH, SMB uses 445, and NFS uses 2049.
• Use SFTP when you only need secure transfers and have SSH, and choose FTPS when existing FTP tooling must stay unchanged.
• Match protocol to platform: SMB for Windows shares, NFS for Linux and Unix storage, and rsync when you need efficient repeated syncing.

A file sharing protocol is the set of rules two systems use to move files between them. The right choice depends on your operating systems, whether the transfer is local or across the internet, and how much you care about encryption and speed. This guide compares the main protocols with their default ports and a plain recommendation for each.

File sharing protocols at a glance

Use this table to shortlist, then read the notes below for the detail that the table cannot hold.

FTP, SFTP and FTPS: what is the difference?

They sound alike but only two of them are secure. FTP sends data and, worse, your username and password in clear text, so anyone capturing the traffic can read them. It is fine on an isolated internal segment and nowhere else.

SFTP is a different protocol built on SSH. It runs over port 22, encrypts everything, and needs only one port open, which makes it firewall-friendly. FTPS is ordinary FTP wrapped in TLS; it keeps the FTP command style but adds encryption, at the cost of trickier firewall rules because of its separate data connections.

Rule of thumb: for new work that must cross the internet, choose SFTP. Keep FTPS only when you are tied to existing FTP software. Avoid plain FTP outside a trusted LAN.

SMB vs NFS: Windows shares vs Linux shares

Both give you a network drive, but they come from different worlds. SMB is the native protocol for Windows file and printer sharing and is what you use for a mapped drive such as \\server\share. Modern SMB 3.x supports encryption and is also spoken by Linux through Samba and by macOS.

NFS is the traditional choice on Linux and Unix. It is light and fast on a local network and integrates with Unix permissions. Older NFS relied on network trust rather than strong authentication, so for anything sensitive use NFSv4 with Kerberos.

Mixed environment? SMB is usually the safer default because every major operating system speaks it. Pure Linux fleet with high throughput needs? NFS often wins.

HTTP, HTTPS and WebDAV

You already use HTTP and HTTPS for file sharing every time you download something from a website. HTTPS adds TLS, so for any download that matters, serve it over HTTPS. WebDAV extends HTTP so clients can also write and edit files on the server, which is how some cloud drives and content systems expose storage. Run WebDAV over HTTPS, never plain HTTP, because credentials travel with each request.

rsync and TFTP

rsync is not a classic share; it copies only the parts of files that changed, which makes it the tool of choice for backups and keeping two directories in sync. Run it over SSH to encrypt the transfer. TFTP is the opposite of feature-rich: no authentication, UDP based, and used for jobs like PXE network boot and pushing firmware to routers and switches on a controlled network. Never expose TFTP to the internet.

How do you choose the right protocol?

1. Does the traffic cross an untrusted network? If yes, pick an encrypted protocol: SFTP, FTPS, HTTPS or SMB 3.x with encryption.
2. What systems are involved? Windows-centric: SMB. Linux-centric and high throughput: NFS. Mixed: SMB or SFTP.
3. What is the job? One-off or scripted transfers: SFTP. Backups and syncing: rsync. Web distribution: HTTPS. Device provisioning on a closed network: TFTP.
4. Firewall constraints? SFTP needs a single port, which is the easiest to allow safely.

What are the common mistakes?

• Using plain FTP over the internet and leaking credentials. Switch to SFTP.
• Confusing FTPS with SFTP in firewall rules. They use different ports and connection models.
• Exposing SMB (port 445) directly to the internet, a frequent ransomware entry point. Keep it behind a VPN.
• Leaving NFS on host-only trust for sensitive data instead of enabling Kerberos.

File sharing sits on top of core networking concepts, so if ports and the transport layer feel shaky, start with the OSI model and how layers map to protocols, then see how addresses are translated in our explainer on Network Address Translation. To watch any of these protocols on the wire and understand what is really being sent, our guide to Wireshark for packet analysis is a good next step. If you want to build networking from the ground up, the CCNA networking training covers protocols, ports and security in depth.

Related reading

• What Are the Different Networking Protocols? A Beginner-Friendly Guide to HTTP, TCP, UDP, FTP, and More
• What are the most common network protocols and how do they work?
• How to Securely Share Data Across Platforms: Encryption, Best Practices, and Tools