1. Configure ssh to login via port 2243 and disable direct root access to the server.
Check port 2243 allready in use
vi /etc/services and search port number
Open /etc/ssh/sshd_config and change below lines
Port 2243
PermitRootLogin no
2. Configure iptables in the machine and block port 22 to deny ssh access from 192.168.1.9
iptables -A INPUT -p tcp --dport 2243 -s 192.168.1.42 -j REJECT
Check port 2243 allready in use
vi /etc/services and search port number
Open /etc/ssh/sshd_config and change below lines
Port 2243
PermitRootLogin no
2. Configure iptables in the machine and block port 22 to deny ssh access from 192.168.1.9
iptables -A INPUT -p tcp --dport 2243 -s 192.168.1.42 -j REJECT