Alright, let's get this out of the way: if you're running anything vaguely important on AWS and you think the standard freebie CloudFront/ALB WAF is "good enough," I've got some sobering news for you. I'm the guy who changes CRMs annually because something always breaks, so naturally, I applied the same restless skepticism to my infrastructure. This year's project: stress-testing AWS's DDoS posture before committing a dime to Shield Advanced.
The setup was painfully simple:
- A mid-tier EC2 instance running a web app with a public-facing ALB.
- The control group: Standard AWS infrastructure (implicit DDoS mitigations) + the free Managed Rules on the WAF.
- The test group: Same setup, but with Shield Advanced enabled (the $3000/month one, because of course you have to commit annually).
- The weapon: A rented "stress testing" service (we all know what that means) capable of generating several attack vectors—volumetric, SSL/TLS renegotiation, and a slowloris-style application layer attack.
The results were, frankly, embarrassing for the "standard" protection.
**Without Shield Advanced:**
- The volumetric attack (just a simple UDP flood) was mitigated *eventually*. Latency spiked to unacceptable levels for a solid 8 minutes before traffic normalized. The docs call this "always-on network monitoring," but the response time felt like a manual review.
- The SSL/TLS attack sailed right through. The free WAF doesn't even look at that. The instance CPU pinned at 100% for the duration.
- The slowloris attack was partially caught by the free AWSManagedRulesKnownBadInputs rule set, but not before it consumed 50% of available connections on the ALB. Performance degradation was immediate and noticeable.
**With Shield Advanced:**
- The volumetric attack was nullified almost instantly. We're talking sub-minute. The traffic graph looked like a cliff edge. This is the 24/7 DRT (DDoS Response Team) they brag about. It's the main differentiator.
- The SSL/TLS attack was identified and mitigated. Shield Advanced includes specific "attack signatures" for these resource exhaustion attacks that the standard WAF lacks.
- The slowloris attack was handled identically to the free tier. No improvement here—application layer is still squarely on the WAF's shoulders, and the rule sets were the same.
My conclusions, for anyone considering the jump:
- The vaunted "always-on" detection in the free tier is sluggish. If your business can tolerate 10+ minutes of degraded performance or outage during a volumetric attack, save your money.
- Shield Advanced is **only** about faster, more automated response to infrastructure layer (L3/L4) attacks. It does not magically make your WAF smarter. You are still responsible for tuning those rules, which is a part-time job in itself.
- The real value, which I couldn't test, is supposedly in cost protection. They promise to cover scaling costs (like CloudFront/ELB) and DRT labor during an event. Given AWS's pricing, that could be the only reason to justify the $36k/year if you're a target. But it's a bet, an insurance policy with opaque payout rules.
In the end, it feels like another vendor lock-in play. You're paying a premium for a faster, automated version of what they already provide minimally for free, plus some vague financial assurances. It made me wonder if a third-party, cloud-agnostic solution would offer more transparency and control. But that's a migration for next year.