The Nessus vulnerability scanner is the gold standard for security professionals, but getting it up and running requires a valid activation code to unlock its full database of security "plugins".

Tenable Support Portal: For enterprise users, codes are often managed within the Tenable Support Portal under the "Activation Code" link in the left-hand navigation menu. How to Use Your Activation Code

Part 1: Understanding Nessus Versions (Crucial Before Getting a Code)

To get the "best" activation code, you must first understand which version of Nessus you are activating. Tenable offers three primary distributions: