How DDoS Defense Works

Understanding the DDoS mitigation process helps you appreciate what happens behind the scenes during an attack.

The Basic Mitigation Flow

Step 1: Traffic Monitoring

• Continuous analysis of network traffic patterns
• Baseline establishment for "normal" traffic
• Real-time comparison to detect anomalies

Step 2: Attack Detection

• Automated systems identify suspicious traffic patterns
• Multiple detection methods working simultaneously
• Alerts triggered when thresholds exceeded

Step 3: Traffic Diversion

• Attack traffic redirected to scrubbing centers
• Methods: BGP routing, DNS redirection, GRE tunneling
• Legitimate users' traffic also diverted for cleaning

Step 4: Traffic Scrubbing

• Malicious traffic filtered and dropped
• Legitimate traffic identified and allowed through
• Multi-layered filtering applied

Step 5: Clean Traffic Delivery

• Only clean traffic forwarded to your infrastructure
• Delivered via secure tunnels or direct routing
• Normal service resumes for legitimate users

Step 6: Continuous Monitoring

• Ongoing analysis during mitigation
• Adaptation to evolving attack patterns
• Attack ends when malicious traffic stops

Always-On vs. On-Demand

Always-On Protection:

• All traffic continuously routed through scrubbing network
• Instant mitigation (no activation delay)
• Best for mission-critical services
• Minimal latency impact with proper architecture

On-Demand Protection:

• Traffic diverted only during detected attacks
• Lower baseline cost
• Activation delay: 5-15 minutes typically
• Suitable for less time-sensitive services

Hybrid Approach:

• Baseline always-on for critical services
• On-demand for secondary services
• Balances cost and protection

Key Success Factors

Scale:

• Scrubbing capacity must exceed attack size
• Distributed infrastructure handles regional attacks

Speed:

• Fast detection (seconds, not minutes)
• Rapid mitigation activation
• Quick adaptation to attack evolution

Precision:

• Distinguish legitimate from malicious traffic
• Minimize false positives
• Surgical filtering, not blanket blocking

Key Takeaway: Effective mitigation requires massive scale, rapid response, and intelligent filtering working together.

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