From following the preceding recipes, a user should be able to understand the creation and selection of a policy. Once the policy has been decided upon, all the user needs to do is to identify the host to be scanned, select the policy, and click Scan. The general scan time for Nessus for a noncredential scan of a single host with few ports open will take a couple of minutes. As the number of hosts and ports keeps increasing, the time required for the scan also becomes high.
It is always recommended to inform the stakeholders before performing a Nessus scan, as it would allow an overhead of incident investigation on whether an attack was performed on the host and also inform network admins as to whether network bandwidth utilization may be higher than it is normally.