If you have a website and want to block certain IP addresses for IP Address will not be able to access your website, you simply create a file with a name. htaccess then place in the main directory of your website.
Inside the .htaccess file, fill in this script:
order deny,allow
#deny from one ip
deny from 192.168.0.100#deny from ip range 192.168.0.0.to 192.168.0.255
deny from 192.168.0
allow from all
ofc, you can change that ip with the real ip you want to blocked.