Lots of people struggle with installing the agent – which is why we are working on improving the process, but until then, we hope you find this article helpful.

Outlined below are some scenarios and troubleshooting steps that we believe – if followed carefully – should remediate the installation issue(s) you're facing. Please bear in mind, it can take a few minutes for the internal system to show on your targets page. If, by the end of this article, you're still having trouble, then please get in touch and we'll do our best to help. 💪

Could there have been a misstep during installation?

Checking the agent status is a great way to figure out if something went wrong during the installation process. And if it did, no worries the lower part of the article includes all the possible scenarios and how to remediate them!

Top tips:

  • Mistakes in the linking command are very common
    (lots of users forget to include the prefix in the name / NESSUS NAME which is what we need to connect your device with your account in the backend. If you omit this, the agent status output could show as linked and connected, but you won't see it in your target list. If you've done this, you'll need to unlink and link again).

  • Running the linking command in the wrong directory is pretty common
    so it's always worth reviewing these two as we'll be checking them first.

Do you have enough licenses?

The internal system won't show if you don't have enough licenses – you must have enough licenses to cover all of the internal targets that have been added to the platform, even if you haven't scanned them yet. (Unscanned external targets don't have any bearing on the license count).

(For example: All licenses will be considered "in use" in the following scenario:
You have 100 licenses, 97 are consumed, three internal targets have been added and are awaiting a scan.)

If you're short, you'll see a notification similar to this in your portal:

How to check your license count

If you're unsure about your current license count, then please head to the targets page. Clicking on 'Licenses' will show you which targets are consuming them, and when they'll be up for release (and can be used on new targets – more on that, here).

How to increase your license count

If you're out of licenses, then you can update your license count by following the instructions in this article.

Trial users

Please note that the trial entitles you to five licenses, which can be used to scan five targets (internal or external) as many times as you like for 14 days. Deleting the target will not release the license. If you have already used all five and would like to test the internal scanner, please get in touch with a member of the team via the chatbot.

Do you need to reboot your system?

Sounds simple – but sometimes turning your machine off and back on again, can do the trick.

Is your internal system connected to the internet?

The agent needs to be able to reach out to cloud.tenable.com on port 443 to return the results to the platform. To test this, open your browser and type: https://cloud.tenable.com

(Windows only)

Did you launch the agent installer correctly?

If you launched the installer after downloading it (step 1), rather than running the command (step 3), you will need to unlink your agent and relink again.


In the terminal, as Admin, run the following command
nessuscli agent unlink

Check that the unlink command worked
Run the agent status, it should return:

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

Link the agent (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 added your prefix and Device name)

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

Do you have anti-virus enabled?

If the answer is yes and you have an IT department, we'd recommend taking a screenshot of the process name in your task explorer (usually something like "nessusagent", "neagent" or similar) and sending it over to them; along with a note that says the agent needs to be able to reach out out to cloud.tenable.com on port 443.

None of these applicable?

Your best bet at this point would be to do the following:

  • Pop a note in the chatbot confirming that you have read this article and eliminated all of the above

  • Please send over:
    ➡️ A screenshot of your agent status command output
    ➡️ A screenshot of the exact linking command you ran (the very first time)
    ➡️ The name / nessus name

  • Hang tight whilst the team investigate.

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