Azure Front Door: Global Load Balancing and CDN

Azure Front Door is a global entry point for web applications. It operates at Layer 7 (HTTP/S), using Anycast protocol to route users to the nearest Point of Presence (PoP), effectively accelerating your app performance via split TCP.

Global Load Balancing

flowchart TB
    UserUS[User US] -->|Anycast| PoPUS[PoP US]
    UserEU[User EU] -->|Anycast| PoPEU[PoP EU]
    
    PoPUS -->|Microsoft Backbone| WebUS[Web App US]
    PoPEU -->|Microsoft Backbone| WebEU[Web App EU]
    
    style PoPUS fill:#FFF3E0
    style PoPEU fill:#FFF3E0

WAF (Web Application Firewall)

Protect against SQL Injection and XSS at the edge.

{
  "policySettings": {
    "enabledState": "Enabled",
    "mode": "Prevention"
  },
  "customRules": [
    {
      "name": "BlockGeo",
      "priority": 100,
      "ruleType": "MatchRule",
      "action": "Block",
      "matchConditions": [
        {
          "matchVariable": "RemoteAddr",
          "operator": "GeoMatch",
          "matchValues": ["KP", "IR"] // Block countries
        }
      ]
    }
  ]
}

Key Takeaways

• Use Front Door for multi-region HTTP/S apps.
• Use **Traffic Manager** for non-HTTP protocols (DNS based).
• Split TCP capability reduces latency for data uploads/downloads.