SSH/SFTP Support

SSH/SFTP is a widely used standard file transfer protocol. It is a de facto standard as implemented by SSH, OpenSSH, and others.

You use the SSH/SFTP protocol to communicate between SFTP servers and SFTP clients.
Note: To correct common misconceptions, SSH/SFTP is not FTP over SSH, nor is it particularly like FTP at the protocol level.

SSH/SFTP has the following characteristics:

  • Tunneled through SSH
  • Widely deployed
  • Used by modern scp (secure copy program) commands
  • Firewall friendly (only one connection)

SSH/SCP is another protocol used to copy files between hosts on a network. It uses secsh for data transfer, and uses the same authentication and provides the same security as secsh. It requests passwords or passphrases if needed for authentication.

The SFTP Server adapter and the SFTP Client adapter support:

  • Version 2 SSH
  • Version 3 SFTP protocol, as supported by OpenSSH
  • Inbound scp commands using SSH/SCP protocol, as supported by OpenSSH
  • Transfers of files 150 Gigabytes or more in size
  • More than 150 concurrent inbound connections from trading partners to the SFTP Server adapter
  • More than 50 concurrent outbound connections from the SFTP Client adapter to trading partners
  • Ability to limit total concurrent sessions and sessions per user
  • Failed login attempt tracking and user account locking
  • Adapter access can be restricted to a selected user or group of users
  • Four methods of required remote user authentication - password, public key, password or public key, or password and public key
  • Importation of Host keys from OpenSSH format
  • Known host verification that requires adding hosts administratively
  • Resumption of transfers to and from the server
  • Random file access, to allow transfer resumption

Sterling B2B Integrator is compatible with most SFTP clients and SCP clients. The following clients have been tested and approved for interoperability with the SFTP Server adapter:

  • Sterling Connect:Enterprise® Secure Client (version 1.3.00)
  • Sterling Connect:Enterprise® Command Line Client (SFTP protocol version 3)
  • OpenSSH (version sftp)
  • GlobalSCAPE CuteFTP (professional version 7.0)
  • Filezilla (version 2.2.10)
    Note: To use Filezilla versions 2.2.11 through 2.2.26a, add the following phrase to the install/bin/tmp.sh file, in the JAVA_FLAGS parameter:

    -Dfilezilla.bug.workaround=true

Important: If you experience a timeout when resuming a file transfer on a very large file, increase the server response timeout value in your SFTP or SCP client to 60 seconds or more.