* vi /etc/ssh/sshd_config:
Port 22
Protocol 2
#Hostkey /etc/ssh/ssh_host_key
PermitRootLogin no
MaxStartups 5:50:10
X11Forwarding no
PrintLastLog yes
LogLevel VERBOSE
PasswordAuthentication no
PermitEmptyPasswords no
Banner /etc/issue
AllowGroups shellusers
* vi /etc/ssh/ssh_config
ForwardAgent no
ForwardX11 no
PasswordAuthentication no
CheckHostIP yes
Port 22
Protocol 2