The IDPS must produce audit records containing information to establish the source of the event, including, at a minimum, originating source address.

Associating the source of the event with detected events in the logs provides a means of investigating an attack or suspected attack. While auditing and logging are closely related, they are not the same. Logging is recording data about events that take place in a system, while auditing is the use of log records to identify security-relevant information such as system or user accesses. In short, log records are audited to establish an accurate history. Without logging, it would be impossible to establish an audit trail.