Gatekeeper is an open source DDoS protection system that provides distributed defense capabilities against distributed denial of service attacks. The system is designed to handle high-bandwidth traffic scenarios and can scale to accommodate varying peak bandwidth requirements. It implements distributed algorithms to detect and mitigate multi-vector DDoS attacks across different attack patterns and methods. The platform targets network operators working in institutional environments, service providers, content delivery networks, and enterprise network infrastructures. It functions as a protective layer that monitors incoming network traffic and applies filtering mechanisms to block malicious requests while allowing legitimate traffic to pass through. Gatekeeper operates as a standalone protection system that can be deployed within existing network architectures to provide DDoS mitigation services without requiring proprietary hardware or vendor-specific solutions.