NeSSi2 is a network simulation tool designed for facilitating research and development in the domains of network security and network analysis. It stands out due to its ability to simulate complex network interactions and cybersecurity events such as intrusion detection systems, making it a valuable tool for assessing and enhancing network security protocols and algorithms. NeSSi2 provides an extensible platform, allowing users to integrate custom plugins and scenarios, which is crucial for accurate network modeling and security analysis.