How I can block specific IP's? And as I know, if I somehow block them, it will be not blocked again after reboot. How I can make a script which will block specific IP's?
答え1
You can add this rule. In --src you also can define various IPs seperated by , (and without spaces!)
iptables -A INPUT --src <the specific IP> -j DROP
Be careful not to lock yourself out though!
For keeping them after reboot read how-can-i-make-a-specific-set-of-iptables-rules-permanent
A quite complete and easy to maintain iptables setup I've found is
DigitalOcean: How to implement a basic firewall template with iptables on Ubuntu 14.04