Tenable Nessus Agent Installation Guide

Nessus Agents are lightweight programs that are installed locally on a host. Agents collect vulnerability, compliance and system data and report that information back to a manager. Nessus Agents currently support Windows, Mac and many flavors of Linux. To see the latest supported operating systems, visit docs.tenable.com and look for System Requirements in the Nessus documentation. Agents run under the local SYSTEM account in Windows or root on Unix-based operating systems, and require sufficient privileges to install software under that account on setup. Nessus Agents are packaged for installation on their respective platforms, and after installation, a scriptable command can be used to register the agent with Tenable.io Vulnerability Management or Tenable On-Prem Agent Managers (for Tenable.sc or Tenable.sc Continuous View). Once agents are connected, they send host and vulnerability reports back to one of these managers. Agents are also managed and updated via the managers.

 

PORTS/PROTOCOLS: By default, Nessus Agents communicate back to Tenable.io Vulnerability Management or On-Prem Agent Managers over TCP port 8834 for On-Prem Agent Manager or port 443 for Tenable.io. That communication is encrypted with AES-256 encryption,

Agents can be linked to Tenable.io using the following setup instructions. Once linked, they will automatically download all necessary plugins. This process takes several minutes and is required before an agent will return results.

 

Agent Setup

Windows

  1. Download the latest installer from
  2. Install the agent on your targets manually or via other third-party software deployment application.
  3. During installation, use the following options to link to this manager:
    • Host: sensor.cloud.tenable.com
    • Port: 443
    • Linking key: 7d880c6f12cdeda84807cdc83bcabbbbd10125a6fd02c6e1b3cd441dca5dd32c

 

macOS

  1. Download the latest installer from
  2. Install the agent on your targets manually or via other third-party software deployment application.
  3. After installing the agent, execute the following terminal command to link to this manager:
    • sudo /Library/NessusAgent/run/sbin/nessuscli agent link \
      --key=7d880c6f12cdeda84807cdc83bcabbbbd10125a6fd02c6e1b3cd441dca5dd32c \
      --host=sensor.cloud.tenable.com \
      --port=443

 

Linux

For Linux platforms, you can run the following command to both install and link, after modifying or removing the name and groups options.

curl -H 'X-Key: 7d880c6f12cdeda84807cdc83bcabbbbd10125a6fd02c6e1b3cd441dca5dd32c' 'https://cloud.tenable.com/install/agent?name=agent-name&groups=agent-gr…' | bash

Note - In the command above name should equal the host DNS name.  Group can be removed from the command as groups will be assigned manually.

Ex.: curl -H 'X-Key: 7d880c6f12cdeda84807cdc83bcabbbbd10125a6fd02c6e1b3cd441dca5dd32c' 'https://cloud.tenable.com/install/agent?name=FQDN.nebraska.edu' | bash

If for some reason the above command did not work, try the below steps to install the agent and activate manually.

Manual Agent Setup

  1. Download the latest installer from
  2. Install the agent on your targets manually or via other third-party software deployment application.
  3. During installation, use the following options to link to this manager:
    • Host: sensor.cloud.tenable.com
    • Port: 443
    • Linking key: 7d880c6f12cdeda84807cdc83bcabbbbd10125a6fd02c6e1b3cd441dca5dd32c