Here I detailed about Installation of APF(Advanced Policy Firewall),DDOS(DDoS is a type of DOS attack where multiple compromised systems, which are often infected with a Trojan, are used to target a single system causing a Denial of Service (DoS) attack), and RKHunter (routekit Hunter) And BFD(Broute Force Detection) Tools for Checking and Blocking unauthorized attempt of login or access to server