You can also view the articles that we explain Hacker Types and Attack Types.
Snort is a well-known open source intrusion detection and prevention. It analyze traffic, creates alerts, and record problematic packets. Rules can be customized based on a specific needs. You can download Snort, below.
https://www.snort.org
IPCop Firewall is a Linux firewall. It is used for Small Offices and Home Users. It has a very user friendly web-interface.You can download IPCop, below.
http://ipcop.org
Security Onion is a Network Security Monitoring and Intrusion Detection based on Linux. It contains Snort, Suricata, Sguil, Squert, argus, Xplico, tcpreplay, scapy, hping, and many other security tools.You can download Security Onion, here.
https://securityonion.net
You can also view the articles that we explain Hacker Types and Attack Types.