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ssh (secure shell) - service name : sshd - log file /var/log/secure* /var/log/audit/audit.log - default configuration files and ssh ports /etc/ssh/sshd_config     --> openssh server configuration file /etc/ssh/ssh_config     --> openssh client configuration file ~/.ssh/     --> user ssh configuration directory ~/.ssh/authorized_keys    ---> lists public key (RSA or DSA) that can be used to log into the user's account /etc/nologin     --> if the file exists, sshd refuses to let anyone except root log in /etc/hosts.allow   /etc/hosts.deny     --> these two file are access control list that should be enforced by tcp-wrappers defined here - ssh default port    ---> tcp:22 - examples of using tcp wrappers for sshd allow ssh only from 192.168.1.2 172.16.23.12 put the line in /etc/hosts.allow sshd : 192.168.1.2 17...