Copyright Goodheart-Willcox Co., Inc. 482 Networking Fundamentals Th e Event Viewer allows network activities to be monitored that may indicate an attempted or successful system intrusion. Look at the Event Viewer security log events of a Windows Server 2016 system in Figure 15-26. Th e security log lists log- on events, successes and failures, dates, and times. By clicking a failed event in the security log, specifi cs about the event are revealed in more detail. Notice the Audit Failure event that is highlighted in middle pane in Figure 15-26. It refers to a failed cryptographic operation. Figure 15-25 An administrator can use the netstat utility to detect open ports on a computer. TCP and UDP Protocols Computer name or address Port number Name or address of remote computer Port number of remote computer Connection state Goodheart-Willcox Publisher Figure 15-26 The Event Viewer security log can be used to monitor the system for an attempted or successful system intrusion. Security log Audit failure Goodheart-Willcox Publisher