The best way to secure your server is with a good firewall.
A firewall is like a bouncer: he allows all the good traffic in, while keeping all the bad traffic out of the club. In this scenario, the club of course is your website.
Cybersecurity tip courtesy of Duncan Garcia from Liquid Web.
Check out our firewall: https://www.liquidweb.com/products/add-ons/firewalls-vpn/