How is a Network Intrusion Detection System (NIDS) typically deployed?

A Network Intrusion Detection System (NIDS) is typically deployed as a passive sniffer at network aggregation points because this allows it to effectively monitor and analyze traffic passing through the network without actively intervening or altering the data flow. By being placed at strategic locations, such as network switches or routers, a NIDS can capture a wide array of packets and analyze them for signs of unauthorized access, misuse, or other malicious activities.

This method of deployment is crucial as it provides a comprehensive view of the network traffic patterns and detects potential threats in real-time without impacting the performance or availability of the network itself. Passive monitoring is essential for maintaining the integrity of the data being transmitted, as an active intervention could inadvertently disrupt legitimate communications.

In contrast, deploying a NIDS as a standalone active agent on user devices would limit its visibility and effectiveness, as it would only be able to monitor individual devices rather than the entire network's traffic. Similarly, while NIDS can be used alongside a firewall for comprehensive security measures, they serve different purposes and are not necessarily reliant on one another for deployment. Placing them on individual laptops to monitor usage could also diminish their ability to detect network-wide threats, as it restricts their monitoring capabilities to a single endpoint rather than the