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Nessus Troubleshooting

Nessus server does not appear to be operational

  1. Verify that the Nessus scanner Status is Unable to Connect.
  2. SSH to the remote Nessus host to make sure the underlying operating system is operational.
  3. Confirm that the Nessus daemon is running (Linux example below):

    # service nessusd status
    nessusd (pid 3853) is running...

  4. If the Nessus service is not running, start the service:

    # service nessusd start
    Starting Nessus services:
    # ps -ef | grep nessusd
    root      8201  8200 60 11:41 pts/2    00:00:05 nessusd –q
    root      8206  7842  0 11:41 pts/2    00:00:00 grep nessusd

Cannot add a Nessus server

  1. Make sure the Nessus daemon was registered using the option for registration.
  2. Check connectivity from to the port the Nessus system is running on (e.g., 8834). For example, run:

    curl -k https://<scannerIPaddress>:<port>

Nessus scans fail to complete

  1. Ensure that the Nessus service is running on the Nessus host.
  2. Ensure that Nessus scanner is listed in under Resources and Nessus Scanners and that the status of the Nessus scanner is listed as Working.
  3. Click Edit to ensure that the IP address or hostname, port, username, password, and selected repositories for the Nessus scanner are all correct.
  4. Edit any incorrect entries to their correct state.
  5. Click Submit to attempt to reinitialize the Nessus scanning interface.
  6. Right click the scan results and click Scan Details to obtain a more detailed description of the error.

    If the scan details indicate a Blocking error, this is indicative of a license IP address count that has reached the limit. Either remove a repository to free up IP addresses or obtain a license for more IP addresses.

  7. Ensure that scan targets are permitted within the configured scan zones.

Nessus plugins fail to update

  1. Click System > Configuration.

    The Configuration page appears.

  2. Click License and ensure that the Nessus Activation Code is marked as Valid.
  3. Ensure that the user used to connect to the Nessus server is configured as an ‘admin’ class user.
  4. Ensure that the system is allowed outbound HTTPS connectivity to the Nessus Plugin Update Site. If it is not, refer to the Nessus 6.x Installation and Configuration Guide for information on offline plugin updates.
  5. Under System, Configuration, and Update in, ensure that Active Plugins is not set to Never.
  6. Manually test a plugin update under Plugins with Update Plugins.

    If successful, the line Active Plugins Last Updated updates to the current date and time.

  7. For all other Nessus plugin update issues, contact Tenable Support.

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