Create a Host Discovery Scan

Knowing what hosts are on your network is the first step to any vulnerability assessment. Launch a host discovery scan to see what hosts are on your network (and associated information such as IP address, FQDN, operating systems, and open ports, if available). After you have a list of hosts, you can choose what hosts you want to target in a specific vulnerability scan.

Note: Hosts discovered by a host discovery scan do not count towards your license limit, if applicable. For more information, see License Utilization.

The following overview describes a typical workflow of creating and launching a host discovery scan, then creating a follow-up scan that target-discovered hosts that you choose. In Tenable Nessus Essentials and Tenable Nessus Professional trials, a wizard walks you through a simplified version of this process. You can always manually launch a host discovery scan or follow-up scan using the workflow outlined in this overview.

  1. In the top navigation bar, click Scans.

    The My Scans page appears.

  2. In the upper right corner, click the New Scan button.

    The Scan Templates page appears.

  3. Under Discovery, click the Host Discovery template.
  4. Configure the host discovery scan:
    • For Name, enter a name for the scan.

    • For Targets, enter targets as hostnames, IPv4 addresses, or IPv6 addresses.

      Tip: For IP addresses, you can use CIDR notation (for example, 192.168.0.0/24), a range (for example, 192.168.0.1-192.168.0.255), or a comma-separated list (for example, 192.168.0.0,192.168.0.1). For more information, see Scan Targets.

    • (Optional) Configure the remaining settings.

  5. To launch the scan immediately, click the down button, and then click Launch.

    Tenable Nessus runs the host discovery scan, and the My Scans page appears.

  6. In the scans table, click the row of a completed host discovery scan.

    The scan's results page appears.

  7. In the Hosts tab, view the hosts that Tenable Nessus discovered, and any available associated information, such as IP address, FQDN, operating system, and open ports.

  1. In the top navigation bar, click Scans.

    The My Scans page appears.

  2. In the scans table, click the row of your completed host discovery scan.

    The scan's results page appears.

  3. Click the Hosts tab.

    Tenable Nessus displays a table of scanned hosts.

  4. Select the check box next to each host you want to scan in your new scan.

    At the top of the page, the More button appears.

  5. Click the More button.

    A drop-down box appears.

  6. Click Create Scan.

    The Scan Templates page appears.

  7. Select a scan template for your new scan.

    Tenable Nessus automatically populates the Targets list with the hosts you previously selected.

  8. Configure the rest of the scan settings, as described in Scan and Policy Settings.

  9. To launch the scan immediately, click the down button, and then click Launch.

    Tenable Nessus saves and launches the scan.