If you are having issues with your internal agent, then it might be worth checking its status. The steps below will walk you through running the command, and interpreting the output.

N.B. This article assumes that nessuscli is installed in the default folder. The default folder for each operating system is:

  • MacOS: /Library/Nessus/run/sbin/

  • Windows: C:\Program Files\Tenable\Nessus Agent\

  • Linux: /opt/nessus_agent/sbin/


  1. Ensure you are running the command as Administrator. (Not admin?)

  2. Open: Command Prompt: Press Windows button (next to alt) + R; type cmd + hit return or Open search bar; type cmd, scroll down to command prompt + click to open

  3. In the terminal type "C:\Program Files\Tenable\Nessus Agent\nessuscli" agent status and hit return.

  4. Check out the options below:


  1. Open Terminal: Press command + space bar, and type terminal

  2. In the terminal type sudo /Library/NessusAgent/run/sbin/nessuscli agent status and hit return.

  3. Check out the options below:


  1. Open a terminal.

  2. In the terminal, type sudo /opt/nessus_agent/sbin/nessuscli agent status and hit return.

  3. Check out the options below:

👉 It says 'command not found' or "'nessuscli' is not recognized"

If the agent status command contains one of these errors:

  • command not found: nessuscli

  • 'nessuscli' is not recognized as an internal or external command

Then it means you that you are not running the command as an Administrator, or you are not in the right directory. The above commands assume that the Nessus agent is installed in one of the default locations, which are:

Linux: /opt/nessus_agent/sbin
MacOS: /Library/NessusAgent/run/sbin/
Windows: C:\Program Files\Tenable\Nessus Agent or similar.

Please ensure that you are running the commands as Administrator on Windows, or using sudo on MacOS and Linux. If you specified an alternative installation directory during setup, you will have to replace the default folder with the directory you specified in the commands above.

👉 It's not 'Running' and 'Not linked to a manager'

Running: No

Linked to: None
Link status: Not linked to a manager

Then it could mean one of two things:

  1. The agent hasn't installed:
    It is possible that your original install command contained errors (wrong filename, wrong path, DeviceName etc) and so we would recommend going back and trying the installation process again.

  2. Your system cannot reach out to tenable
    You need to check that you are connected to the internet and that the agent can reach out to cloud.tenable.com on port 443. (This is the only relevant firewall rule). When you are certain that the system is connected to the internet, try running the command again. If it still says "not linked to a manager" then you will need to try the installation process again.

👉 It's 'Running', but it is 'Not linked to a manager'

Running: Yes

Linked to: None
Link status: Not linked to a manager

Although it says 'running', the link status here tell us that something has gone wrong during the installation. To resolve this, you'll need to link again:

Link (again):

  1. Open the command terminal again – as Administrator

  2. Run the link command below
    (*Make sure you are in the right folder and have replaced DeviceName with your unique device name. Instruction on how to do that are here.)

    nessuscli agent link --host="cloud.tenable.com" --port="443" --key="819652a91d674e8d5be08e21299f1a3c69bd9806c72e24bc05df6b32b8db7fe1" --name="[DeviceName]"
  3. Check out the targets page to see if it has appeared.

👉 It's not 'Running', but is linked to a manager

Running: No
Linked to: cloud.tenable.com:443
Link status: connection has not been attempted

This means that the agent isn't running and you need to (re)start the service manually. To do this, reboot the internal system (if possible).

👉 It's Running and is linked, but I still can't see my internal system on the targets page. What now?

Running: Yes
Linked to: cloud.tenable.com:443
Link status: Connected to cloud.tenable.com:443

This means that it has linked to Tenable, but there is an underlying issue that is stopping it from working as intended.

Your best bet is to start over.

  1. Unlink the agent
    In the terminal, as Admin, run the following command: nessuscli agent unlink

  2. Check that the unlink command worked by running the agent status
    It should return:

    Linked to: None
    Link status: Not linked to a manager

  3. Uninstall the agent
    Follow the steps in the relevant OS guide (including any appended notes).

  4. Reboot the system.

  5. Re-add the internal system, following the steps in our installation articles.

  6. Check out the targets page to see if it has appeared.

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