Blarp - Kerio Personal Firewall FAQ FAQ for Kerio Personal Firewall. Kerio Personal Firewall (KPF) is a software agent that builds a barrier between your personal computer and the Internet. KPF is designed to protect your PC against attacks from both the Internet, and other computers in the local network. KPF controls all data flow in both directions – from the Internet to your computer and vice versa, and it can block all attempted communication allowing only what you choose to permit. This makes KPF an ideal solution for notebook computers that freely travel in and out of the corporate network, facing exposure to various risks as they connect from different locations.