SSH Tectia  
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    About This Document >>
    Installing SSH Tectia Server for IBM z/OS >>
    Getting Started with SSH Tectia Server for IBM z/OS >>
    Configuring the Server >>
    Configuring the Client >>
    Authentication >>
    File Transfer Using SFTP >>
    File Transfer Using Transparent FTP Tunneling >>
    Tunneling on the Command Line
        Local Tunnels >>
        Remote Tunnels >>
        Tunneling FTP on the Command Line >>
        Agent Forwarding
    Troubleshooting SSH Tectia Server for IBM z/OS >>
    Advanced Information >>
    Man Pages >>
    Log Messages >>

Tunneling on the Command Line

Tunneling is a way to forward otherwise unsecured TCP traffic through Secure Shell. Tunneling can provide secure application connectivity, for example, to POP3-, SMTP-, and HTTP-based applications that would otherwise be unsecured.

The Secure Shell v2 connection protocol provides channels that can be used for a wide range of purposes. All of these channels are multiplexed into a single encrypted tunnel and can be used for tunneling (forwarding) arbitrary TCP/IP ports.

The client-server applications using the tunnel will carry out their own authentication procedures, if any, the same way they would without the encrypted tunnel.

The protocol/application might only be able to connect to a fixed port number (e.g. IMAP 143). Otherwise any available port can be chosen for tunneling. For remote (incoming) tunnels, the ports under 1024 (the well-known service ports) are not allowed for the regular users, but are available only for system administrators (root privileges).

There are two basic kinds of tunnels: local and remote. They are also called outgoing and incoming tunnels, respectively. Agent forwarding is a special cases of a remote tunnel.

Local Tunnels

Remote Tunnels

Tunneling FTP on the Command Line

Agent Forwarding

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