Firewall
You can install CSF firewall to protect your network, Installation commands :
cd /usr/src
rm -fv csf.tgz
wget https://download.configserver.com/csf.tgz
tar -xzf csf.tgz
cd csf
sh install.sh
To test CSF required modules :
perl /usr/local/csf/bin/csftest.pl
Don't worry if you cannot run all the features, so long as the script doesn't report any FATAL errors
Full installation manual : https://www.configserver.com/cp/csf.html
Secure SSH
Try not to use port 22 for SSH login. change it from /etc/ssh/sshd_config file to another number for example : 1527 and save it. Open the port number in your firewall rules and run :
service sshd restart
