Why this talk. Co-SAGE interest in SSH and security:5: Security or security tool usage2: Configuring SSH3: VPN (1 specifically VPN tunneling via SSH)Added SSL since it fits some niches better. Layer model: insecure protocols. Application layer:RSH, Telnet, FTPTransport layer: TCP, UDPNetwork layer: IP, IPX, EtherTalkLink layer: Ethernet, PPPPhysical layer: CAT-5 cable, WirelessNetwork security? Confidentiality, Integrity, and Endpoint Authentication.