As businesses grapple with the pandemic, millions of workers are no longer working in the traditional office behind the traditional perimeter. They are working from home, accessing data and network resources using unauthorized devices, unauthorized software and unsecured WiFi. This is where intrusion detection systems (IDS) come in. An IDS monitors the network for suspicious behavior and issues alerts when such activities are discovered. Snort is the oldest IDS and almost a de-facto standard IDS in the open-source world.”]
Source: https://www.csoonline.com/article/3596315/5-open-source-intrusion-detection-systems-for-smbs.html