Which tool or utility allows a user to watch network traffic in real time to identify a target?

The chosen answer, a sniffer, is correct because it is a specialized tool or utility designed to capture and analyze network traffic in real time. By monitoring the data packets that travel across the network, a sniffer allows users to view various details such as the source and destination IP addresses, protocol types, and the data contained within the packets. This capability is essential for network analysis, troubleshooting, and identifying potential security threats, as it helps administrators or security professionals to understand the traffic patterns and detect suspicious activities.

In contrast, port scanning is more about probing a remote server or device for open ports and services that are running, rather than observing live traffic. Antivirus software primarily focuses on detecting and preventing malware from executing on a system, providing protection against known threats but not capturing real-time network traffic. Similarly, port redirection refers to rerouting traffic from one port to another, which does not facilitate real-time traffic monitoring but instead alters the path taken by data packets. Therefore, the sniffer is the most suitable tool for the described purpose of monitoring network traffic in real time.