Licensing Requirements

Agents are licensed through the product that manages them: Nessus Manager or

Nessus Manager

Nessus is available to operate either as a subscription or managed by Nessus requires a plugin feed Activation Code to operate in subscription mode. This code identifies which version of Nessus that Tenable licensed you to install and use, and if applicable, how many IP addresses you can scan, how many remote scanners you can link to Nessus, and how many Nessus Agents you can link to Nessus Manager. Nessus Manager licenses are specific to your deployment size, especially for large deployments or deployments with multiple Nessus Manager instances. Discuss your requirements with your Tenable Customer Success Manager.

You must obtain the Activation Code before starting the installation process and setting up Nessus.

Your activation code:

  • is a one-time code, unless your license or subscription changes, at which point Tenable issues you a new activation code.
  • must be used with the Nessus installation within 24 hours.
  • cannot be shared between scanners.
  • is not case-sensitive.
  • is required to manage Nessus offline.

    Note: For more information about managing Nessus offline, refer to the Nessus User Guide.

    Note: See the Obtain an Activation Code page and the Licensing and Downloading video for instructions on how to obtain and use an Activation Code.

For managed Nessus scanners, the Activation Code and plugin updates are managed from You must start Nessus before it communicates with, which it normally does not do without a valid Activation Code and plugins. To have Nessus ignore this requirement and start (so that it can get the information from, when you register your scanner, select Managed by SecurityCenter.