# DDoS Protection Specification

## Overview

DDoS protection via WAF, CDN, and rate limiting.

## WAF Rules

### Rule Categories

**1. IP Reputation**:
- Block known malicious IPs
- Rate limit suspicious IPs

**2. Request Patterns**:
- Detect bot patterns
- Block automated attacks

**3. Geographic**:
- Optional geographic restrictions
- Block high-risk regions

## CDN Integration

**Provider**: Cloudflare
**Benefits**: 
- DDoS mitigation
- Geographic distribution
- Caching

## Rate Limiting Strategies

### Rate Limit Levels

**Per IP**: 100 requests/minute
**Per API Key**: Based on tier
**Per Endpoint**: Varies by endpoint complexity

### Implementation

**Method**: Token bucket or sliding window
**Storage**: Redis for distributed rate limiting
**Headers**: Rate limit headers in responses

## IP Blocking and Whitelisting

### Blocking

**Automatic**: Block IPs exceeding rate limits
**Manual**: Admin can block specific IPs
**Temporary**: Auto-unblock after cooldown period

### Whitelisting

**Use Case**: Known good IPs (partners, internal)
**Implementation**: Bypass rate limits for whitelisted IPs

## References

- API Gateway: See `../api/api-gateway.md`
- Security Architecture: See `security-architecture.md`