I have website that identifies users only by their IPs. That makes it very difficult to keep it secure against unwanted users/attackers. They can simply change their IP by using VPN services that provides them numerous variety of IPs. So what I want is to not just blocking one IP but entire IPs under subnets of a VPN service, once attacker used one of them.
How to block entire IPs of a VPN server by IP
security;ip address;vpn