This set of rules is a compilation of protections against various attacks (smurf, xmas)
Ferm (for Easy Rule Making) ferm is a tool to maintain complex firewalls, without having the trouble to rewrite the complex rules over and over again. ferm allows the entire firewall rule set to be stored in a separate file, and to be loaded with one command. The firewall configuration resembles structured programming-like language, which can contain levels and lists.
Yoda-BZH