SFTP is commonly used by businesses to securely transfer files so it is important to understand SFTP and that SFTP uses port 22.
Secure File Transfer Protocol
Although many think SFTP is an acronym for “Secure File Transfer Protocol”, it actually stands for SSH File Transfer Protocol. The encrypted protocol SSH (Secure Shell) is used to encrypt the connection before any files are transferred. This results in any and all files sent over SFTP being encrypted. There is no way to send files unencrypted over SFTP.
SFTP Uses Port 22
Since SFTP runs over the SSH protocol as a subsystem, SFTP uses port 22 by default. The SSH server at port 22 listens for client requests. The port number can be changed, if desired, for testing or other reasons.
The Internet Assigned Numbers Authority (IANA) assigned TCP port 22, UDP port 22 and SCTP port 22 for the SSH protocol. Described in the context of SSH-2, SFTP uses TCP.
How SFTP Server Authenticates with Client
Before an SFTP file transfer can occur, the client and server verify the connection via a three-way Transmission Control Protocol (TCP) handshake. The handshake occurs in a series of messages between the server and client to confirm both have access to the correct port (22) in the transport layer.
Next, the server authenticates the client using an SSH key pair. The key pair contains a public key, which both parties know, and a private key, which should only be known to the valid client.
Once SSH authentication is successfully completed, the file is transferred over the encrypted channel in packets. Each packet contains some of the data being transferred. At the receiving end, the packets are assembled into the original file.
For an in depth understanding of SFTP, please read What Is Secure File Transfer Protocol (SFTP)?
Using SFTP with Managed File Transfer Software
As file transfer volumes increase, SFTP begins to fall short as a complete file transfer solution. Keeping up with demands to onboard more partners, scale infrastructure and troubleshoot issues can overwhelm your IT team. Furthermore, sensitive, business-critical file transactions require additional protection, control and visibility to meet security and governance requirements.
Managed file transfer (MFT) solutions provide this required functionality. Thru is a cloud-based service that utilizes multiple protocols, including SFTP, to provide comprehensive end-to-end security; granular tracking, logging and retention settings; and high availability. Visit our secure file transfer page to learn more about the added security and visibility of Thru’s MFT»
FAQs
SFTP uses port 22 – this is the only port to configure, making SFTP quick and easy to implement.
Does SFTP use port 21 or 22? ›
Since SFTP runs over the SSH protocol as a subsystem, SFTP uses port 22 by default. The SSH server at port 22 listens for client requests. The port number can be changed, if desired, for testing or other reasons.
Is SFTP port 22 or 115? ›
By default, SFTP uses port 22 for the control connection.
Does SFTP use port 443? ›
SFTP Requires ports 22 or 990 to be open, which is prone to malware including the likes of infamous offenders like Wannacry, Sasser, Nimda, Petya/NotPetya, and more.
Is port 23 used for SFTP? ›
Unlike FTP over SSL/TLS (FTPS), SFTP only needs a single port to establish a server connection — port 22.
How do I know if SFTP port 22 is open? ›
How to check if port 22 is open in Linux
- Run the ss command and it will display output if port 22 opened: sudo ss -tulpn | grep :22.
- Another option is to use the netstat: sudo netstat -tulpn | grep :22.
- We can also use the lsof command to see if ssh port 22 status: sudo lsof -i:22.
The option to enable port 2222 for SFTP servers with VPC endpoints is available in all AWS Regions where Transfer Family is available. To learn more about how to configure an alternate port on your SFTP server, visit our documentation.
What is the difference between port 21 and port 22? ›
Anyway, port 21 is used for FTP protocol (and FTPS with explicit TLS/SSL encryption). Port 22 is used for SSH/SFTP protocol. WinSCP automatically uses the correct port number, when you specify the respective protocol. Usually it is not necessary to specify the port number explicitly.
How to connect to SFTP port 22? ›
Simply access the firewall settings to allow connections over port 22. For Linux, the process might involve installing SSH (if it isn't already installed) using your distribution's package manager, then allowing SSH/SFTP connections through your firewall with a command like sudo ufw allow ssh .
What is the difference between FTP and SFTP? ›
FTP is the traditional file transfer protocol. It's a basic way of using the Internet to share files. SFTP (or Secure File Transfer Protocol) is an alternative to FTP that also allows you to transfer files, but adds a layer of security to the process.
No, SFTP (Secure File Transfer Protocol) does not use TLS (Transport Layer Security). SFTP is actually an extension of the SSH (Secure Shell) protocol and, as such, it utilizes the security mechanisms provided by SSH, which include strong encryption, authentication, and data integrity.
What port does SFTP use for TLS? ›
The ports for each protocol are as follows:
- FTP: 21 (FTP) 10000-10099 (data transfer)
- FTPs: 989-990 (TLS 1.0/1.1) 10100-10199 (data transfer)
- FTPes: 21 (TLS 1.2/1.3) 10000-10099 (data transfer)
- SFTP: 22 (SSH)
Typically, SFTP is faster when compared to HTTPS for transferring larger files as it is typically designed for transferring files and can make more efficient use of bandwidth.
What is the best port for SFTP? ›
SFTP uses port number 22 by default, facilitating secure data movement over a single internet connection. This SFTP port assignment allows SFTP to offer enhanced security and simplicity compared to other protocols like FTP/S, which require multiple ports.
Does SFTP use port 115? ›
Simple File Transfer Protocol (SFTP), which uses the Transmission Control Protocol port number 115, is an unencrypted, simplified form of File Transfer Protocol (FTP). It is less powerful than FTP and contains certain helpful features that are missing from Trivial FTP (TFTP).
What is the TCP port for SFTP? ›
SFTP runs over an SSH session, usually on TCP port 22. It has been around since late 1990s. The acronym actually stands for "SSH File Transfer Protocol".
Does FTPS use port 21? ›
FTPS is configured in passive mode, with Port 21 for the initial connection and the port range of 4460 to 4500 for the data connection.
What network ports does SFTP use? ›
SFTP runs over an SSH session, usually on TCP port 22. It has been around since late 1990s. The acronym actually stands for "SSH File Transfer Protocol".
Does SFTP use TLS? ›
No, SFTP (Secure File Transfer Protocol) does not use TLS (Transport Layer Security). SFTP is actually an extension of the SSH (Secure Shell) protocol and, as such, it utilizes the security mechanisms provided by SSH, which include strong encryption, authentication, and data integrity.
Is FTP port 21 secure? ›
TCP port 21 is the default port used by File Transfer Protocol (FTP) to transfer files between systems over a network. An unrestricted inbound access to this port can allow attackers to connect to the FTP server and potentially exploit vulnerabilities, leading to unauthorized access or data exfiltration.
