Zeek (formerly Bro)Intrusion Detection
Zeek is a network analysis framework that focuses on network security monitoring. Zeek provides a platform for general network traffic analysis while bridging the gap between academic opinions of security and operational security.
Security OnionIntrusion Detection
Security Onion is an open source platform used for intrusion detection, enterprise security monitoring, and log management. The tool features an easy-to-use setup wizard that quickly creates sensors for enterprises.
Suricata is an open source network for threat detection. Suricata is capable of detecting intrusions in real-time and offers functionality for inline intrusion prevention (IPS), network security monitoring (NSM) and offline pcap processing. Suricata inspects network traffic using rules and signature language. Suricata’s development team focuses on security, usability and efficiency.
Snort is an open source network intrusion detection and prevention system.
OSSEC is a Intrusion Detection System. Use OSSEC to secure your business through configuration tools, custom alerts, rules, and writing scripts.
EasyIDS is an open source Intrusion Detection System with a beginner-friendly design.