Step 4: Enable SSH Server Authentication The P-7500 system is accessed through the Secure Shell (SSH) protocol. Telnet is not supported. The P-7500 system uses the SSH protocol to provide secure system access between the management server and devices. SSH provides greater security by encrypting all information before transmission across the network. Through Public Key Cryptography, SSH provides an encrypted terminal connection for server authentication with integrity checks and replay detection. Private keys are then used to transfer information across the network. Since the Internet Engineering Task Force (IETF) specifies SSH, SSH is widely deployed, commonly used, and secure interoperability is assured. There are currently two SSH protocols: SSH version 1 (SSHv1), and SSH version 2 (SSHv2). SSHv1 and SSHv2 are different, and incompatible, protocols. SSHv2 is considered more secure than SSHv1 and is currently being developed as the IETF standard. SSHv1 is based on the V1.5 protocol, while SSHv2 is based on the V2 protocol. SSHv2 is regarded as more secure than SSHv1, and is the only SSH protocol supported by the SSH daemon server on the P-7500 system. To enable a client to establish SSH connections with the P-7500 system: 1. Obtain and install a third-party commercial SSH client on the host computer from which you want to administer the P-7500 system. PuTTY is a well-known and free SSH client application that supports SSHv2. For information on obtaining PuTTY SSH software for use by a client application, see http://www.chiark.greenend.org.uk/~sgtatham/putty/. 2. The SSH server daemon starts when the P-7500 system starts. Once started, the daemon listens for traffic on TCP port 22. You have completed this procedure. Chapter 4