Using Cloudflare and Palo Alto Together on AWS

✅ Potential Benefits (Why People Do This)

  • Cloudflare: DDoS protection, WAF, CDN, TLS offload, bot protection — global edge network.
  • Palo Alto VM-Series: Layer 4-7 inspection, IPS/IDS, app-level policies, advanced logging, east-west traffic inspection within VPCs, integration with enterprise tooling.

⚠️ Potential Downsides

1️⃣ Latency and Performance

  • Cloudflare terminates TLS at edge, then re-encrypts to origin (your AWS app).
  • Introducing Palo Alto in-line can add latency and path complexity.
  • Improper design can cause hairpinning (traffic looping between VPCs/interfaces).

2️⃣ Cost Overhead

  • Palo Alto VM-Series is costly — licensing, compute, bandwidth.
  • Running both Cloudflare and Palo Alto may duplicate features and increase total cost.

3️⃣ Operational Complexity

  • Two security stacks mean two dashboards, two logging systems, two policy engines.
  • Increased burden on security and operations teams.
  • Clear ownership boundaries required (who manages Cloudflare vs Palo Alto?).

4️⃣ Debugging Complexity

  • Failures may require debugging across multiple layers:
    • Cloudflare edge rules
    • Cloudflare WAF
    • Palo Alto firewall policies
    • AWS NACLs, Security Groups, ALB settings

5️⃣ TLS / Encryption Conflicts

  • Careful design needed for TLS termination:
    • Cloudflare terminates TLS, then Palo Alto inspects plaintext? (often not desirable)
    • Cloudflare passes through TLS, Palo Alto inspects encrypted traffic (requires decryption licenses and proper configuration).
  • Improper handling can break mTLS or other sensitive integrations.

6️⃣ Overlap in Features

  • Cloudflare Advanced WAF is powerful.
  • Palo Alto WAF/IPS may introduce redundant protection.
  • Requires careful coordination to avoid double blocking and false positives.

7️⃣ Routing & Asymmetry

  • Improper architecture can cause asymmetric routing:
    • Inbound path through Cloudflare & Palo Alto.
    • Outbound path bypasses Palo Alto.
  • This can break stateful firewalling and cause unpredictable behavior.

Summary — When It Makes Sense vs Not

Situation Recommended Approach
Simple public web apps with Cloudflare Cloudflare alone often suffices
Complex apps needing deep inspection, East-West security Add Palo Alto, but plan architecture carefully
High traffic apps with latency sensitivity Be wary of inserting Palo Alto in-line unnecessarily
Highly regulated industries (finance, healthcare) Using both may be needed for compliance and reporting

✅ Recommendation: Simple Public Web Apps

For simple public web applications — marketing sites, basic informational apps, low-sensitivity data — Cloudflare alone typically provides sufficient protection:

  • Global DDoS protection
  • Advanced WAF and bot management
  • Global CDN and TLS termination
  • Minimal operational overhead

Adding Palo Alto in such scenarios may introduce unnecessary cost and complexity.

✅ Recommendation: Complex High-Traffic eCommerce Web Apps

For high-traffic eCommerce applications with sensitive data (PII, PCI), compliance needs, and fraud prevention requirements:

  • Use Cloudflare for edge security (DDoS, TLS, global CDN, bot mitigation).
  • Use Palo Alto VM-Series for:
    • Deep application inspection
    • Advanced IPS/IDS
    • East-West traffic security between microservices
    • Detailed logging and forensic analysis

For best performance, ensure traffic paths and TLS flows are carefully designed to avoid latency spikes and asymmetric routing.

Final Advice

  • Carefully design traffic path and TLS termination points.
  • Define clear responsibility boundaries between Cloudflare and Palo Alto management.
  • Monitor latency and debug complexity continuously.
  • Justify the cost of dual stack vs using either one effectively.