Server-side protocols

SFTPPlus supports all main open standard file transfer protocols including:

  • FTP
  • Explicit FTPS / FTPES (over TLS)
  • Implicit FTPS / FTPIS (over SSL)
  • SFTP (over SSH version 2)
  • SCP (over SSH version 2)
  • HTTP
  • HTTPS

We continuously test the server to assure it fully complies with RFCs and de facto implementations.

An overview of the supported server-side protocols are in the Users Guide Protocols section.

Below is a non-exhaustive list of file transfer clients used for testing and validating the server:

  • WinSCP for SFTP
  • Filezilla for FTP / FTPS / SFTP
  • OpenSSH SCP and SFTP client
  • Putty SCP and SFTP client
  • cURL for FTP / FTPS / SFTP
  • Gnome Nautilus for FTP and SCP
  • Windows Explorer for FTP
  • WS_FTP LE
  • Core FTP LE
  • Cisco IOS/IOS-XE/IOS-XR/FXOS/ASA SCP and FTP

All file transfer protocols are standard TCP/IP servers for which ports can be forwarded, or the whole server can be contained inside a DMZ.

FTP / FTPS / SFTP / SCP

The server fully implements the file transfer protocol RFCs for FTP / FTPS and SFTP.

SCP protocol is not publicly documented or specified within a standard. Our implementation is based on OpenBSD SCP command line tools. SCP protocol is implemented as a stand-alone, embedded service and no external SCP binaries are required.

Some optional commands from FTP protocol are not available, but we are working to extend our coverage of available FTP commands. Please contact us if the list of implemented commands does not list a command you need. Secure FTP is provided in both implicit and explicit variants.

HTTP / HTTPS Server

The HTTP / HTTPS file transfer server is implemented based on an independent embedded HTTP server. You don't need to install an Apache HTTPD Server, Microsoft IIS or any other generic HTTP server.

The files are made available using a simple web based application which is designed to work with any web browser and can be used without JavaScript or Cookies.

If the browser supports JavaScript or Cookies, the web application will automatically make use of these features to improve functionality and user experience.

Further details are available at the HTTP and HTTPS service page in the documentation.