To configure scan policies in Nessus, one must first have a functional copy of Nessus installed on the Kali Linux penetration-testing platform. Because Nessus is a licensed product, it does not come installed by default in Kali. For more information on how to install Nessus on Kali, refer to the Installing Nessus on Kali Linux recipe in Chapter 1, Getting Started. Additionally, at least one scan policy will need to be created prior to scanning with Nessus. For more information on creating scan policies in Nessus, refer to the preceding recipe.