What to do when the game server is under a DDoS attack?

 As someone in the gaming industry, I've weathered numerous DDoS storms. I know the gut-wrenching feeling when servers suddenly lag, players flood support channels, and ops teams pull all-nighters. Today, let's have a heart-to-heart about what to do when your game servers face a DDoS attack.

I. Understanding DDoS Attacks & Common Types

What is a DDoS attack?

See this diagram? Attackers act like malicious conductors, orchestrating "zombie devices" (infected PCs, cameras, even smart fridges) into botnets. These devices bombard your servers with traffic, like 100,000 people trying to squeeze into a 100-person store—legit players get locked out.

Common Attack Types

Table Notes: 5 stars = hardest to defend. CC attacks are toughest due to indistinguishability from normal traffic.

II. Building Defense Systems

2.1 Hardware Hardening

• Bandwidth Redundancy: Keep 30% extra bandwidth—like emergency highway lanes.
• Load Balancers: Distribute traffic across servers to prevent overload.
• Specialized Firewalls: Use next-gen firewalls with DDoS modules—server armor.

2.2 Software Protections

• Traffic Scrubbing: Cloud services filter malicious traffic automatically.
• IDS (Intrusion Detection): 24/7 monitoring for suspicious patterns.
• WAF (Web Application Firewall): Blocks malicious HTTP requests.

2.3 Network Architecture

• CDN Acceleration: Content Delivery Networks absorb attacks while speeding access.
• BGP High-Defense IPs: Auto-switches IPs under attack via multi-line routing.
• Hybrid Cloud: Host core services in private clouds, edge services in public clouds.

2.4 Backups & Disaster Recovery

• Data Backups: Daily full backups + real-time incremental backups.
• Offsite Servers: Deploy backups in another city for quick failover.
• Snapshots: Regular server "snapshots" enable rapid rollback.

III. During an Attack

3.1 Attack Identification

1. Traffic Alerts: Trigger alarms if bandwidth >80% for 5+ minutes.
2. Pattern Analysis: Check for identical requests, unusual geolocation spikes.
3. Service Checks: Use ping tests/port scans to confirm server responsiveness.

3.2 Emergency Response Flowchart

mermaid复制代码graph TD  A[Detect Abnormal Traffic] --> B{Identify Attack Type}  B -->|UDP/SYN Flood| C[Activate Traffic Scrubbing]  B -->|HTTP Flood| D[Adjust WAF Rules]  B -->|CC Attack| E[Enable CAPTCHA + Rate Limiting]  C --> F[Contact ISP to Block Malicious IPs]  D --> F  E --> F  F --> G[Monitor + Notify Players]

3.3 Actionable Steps

• Traffic Scrubbing: Login to CDN5 console and enable protection.
• **Nginx Rate Limiting*:

nginx复制代码# Nginx Configuration Examplelimit_req_zone $binary_remote_addr zone=one:10m rate=10r/s;server {  location /login {    limit_req zone=one burst=20 nodelay;  }}

IV. Proactive DDoS Prevention

Let's be real—DDoS is like the common cold now. Last month, a neighboring studio got hit, servers down for 3 hours, forums erupted. Attackers' botnets now number in the hundreds of thousands—your servers can't handle that flood alone. You need CDN partners.

CDN Anti-DDoS Strategies

• Traffic Dispersion: Spread requests across global nodes—divert the flood.
• Static Caching: Serve images/audio from CDN nodes, reducing server load.
• Smart Filtering: CDN WAFs block CC attacks while allowing legitimate traffic.

CDN Provider Comparison

Table Notes: 5 stars = strongest mitigation. Choose based on player locations and budget.

Additional Defenses

• Hardware: Triple your baseline bandwidth (e.g., 100Mbps → 300Mbps).
• Load Balancing: Use F5 or Nginx for Layer 7 balancing.
• Monitoring: Deploy Zabbix/Prometheus with 80% bandwidth alerts.
• Rate Limiting: Token Bucket algorithm for login attempts.

Defense is layered—CDN is the moat, but you need walls (hardware), guards (ops teams), and rations (emergency plans). Run quarterly drills to keep your team sharp. Remember: The best defense makes attackers think twice about cost vs. reward.

Need CDN advice? Reach out to CDN5 for expert guidance!