$ sudo vim /etc/ssh/sshd_config
$ sudo vim /var/log/secure
Port 65531 # ssh port to modify the default 22
ListenAddress 192.168.1.X # ssh allows the IP address of the login
PermitRootLogin no # root prohibited via ssh
AllowUsers test@192.168.1.* # allows the user to test the IP 192.168.1. * Client Access Login
Compression no
Compression delayed
LoginGraceTime 6
MaxAuthTries 3
MaxSessions 6
PrintLastLog yes
ClientAliveInterval 900
ClientAliveCountMax 0
$ sudo ls -l /etc/ssh/*key
$ sudo chmod 0600 /etc/ssh/*key
$ sudo grep -i hostkey /etc/ssh/sshd_config
$ sudo ls -l /etc/ssh/*pub
$ sudo chmod 0644 /etc/ssh/*pub