Understanding the server architecture

There are two primary components to WS_FTP Server.

• Listener. A listener acts as the gateway to one or more hosts. A listener accepts connections on a specific IP address and port over a specific protocol (either FTP or SSH), then routes the connection to the appropriate host.
  There are two types of listeners:
  • FTP. FTP listeners provide access to hosts via the FTP protocol. FTP listeners can be configured to provide simple FTP access, both FTP and SSL access, or SSL access only (Implicit SSL).
  • SSH. SSH listeners provide access to hosts using the SFTP protocol over SSH2.

    Note: When WS_FTP Server is installed, three listeners are created by default: one listens on all available IP addresses on port 21 for FTP connections; one listens on port 990 for Implicit SSL connections; and one listens on all available IP addresses on port 22 for SSH connections.

  For more information about listeners, see Setting Up Listeners. For more information about SSL, see Configuring SSL for a Host.

• Host. A host is the portion of the server that authenticates users and grants them access to the files and folders stored on the host. In addition to users and permissions, virtual folders, rules, notifications and SITE commands are defined and configured as part of the host. For more information about hosts, see Setting Up Hosts.