ZyXEL Communications 2 Plus 21.5 SSH, 21.6 How SSH Works

Chapter 21 Remote Management

21.5 SSH

You can use SSH (Secure SHell) to securely access the ZyWALL’s SMT or command line interface. Specify which interfaces allow SSH access and from which IP address the access can come.

Unlike Telnet or FTP, which transmit data in plaintext (clear or unencrypted text), SSH is a secure communication protocol that combines authentication and data encryption to provide secure encrypted communication between two hosts over an unsecured network. In the following figure, computer A on the Internet uses SSH to securely connect to the WAN port of the ZyWALL for a management session.

Figure 252 SSH Communication Over the WAN Example

21.6 How SSH Works

The following table summarizes how a secure connection is established between two remote hosts.

Figure 253 How SSH Works

1Host Identification

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