Protecting Game Servers Against DDoS Attacks: UDP Flood Anatomy & Cloudflare WAF Rules
· 6 min read
Online game servers and community websites are frequent targets of Distributed Denial of Service (DDoS) attacks. Many multiplayer games use UDP as well as TCP. Their traffic requires protocol-aware filtering; a web application firewall alone does not protect a game server.
1. Anatomy of Infrastructure Attacks
- Volumetric Attacks (L3/L4):Bandwidth saturation attacks (NTP Amplification, DNS Reflection, UDP Flood) reaching hundreds of Gbps.
- Protocol State Exhaustion (TCP SYN Flood):Exhausting OS connection tracking tables by flooding spoofed SYN packets without completing the TCP three-way handshake.
- Application Layer Attacks (Layer 7 HTTP Flood):Simulating legitimate client requests targeting resource-intensive database queries or API endpoints.
2. Protecting HTTP & API Services with Cloudflare WAF
The first line of defense for web portals and APIs is hiding your server's Origin IP behind Cloudflare's global Anycast network:
- Enable Cloudflare Proxy (Orange Cloud):Prevents attackers from discovering your origin server IP via public DNS lookups.
- Cloudflare WAF Rate Limiting:Enforce strict per-IP request limits on sensitive POST endpoints (such as
/api/clicker.php) to block automated flood scripts. - Strict SSL & Origin Rules:Drop all direct non-Cloudflare traffic at the OS firewall level using
ufworiptables.