Why the Comparison Will Matter for 2026 Uptime
APIs now front every digital service, while load balancers keep traffic flowing to backend apps. Both are critical for availability – and both can hide DDoS blind spots if you never validate them under continuous and live conditions.
In 2025, DDoS attacks reached unprecedented scale, with Cloudflare reporting a record-breaking 11.5 Tbps attack in Q2. Their Q2 2025 DDoS Threat Report also highlighted a 358% year-over-year increase in total attacks during Q1, reaching 20.5 million incidents. These trends confirm that attack frequency and intensity are accelerating, and that relying on default configurations in gateways or load balancers are not acceptable.
API Gateway Basics
An API gateway is a Layer 7 control plane that centralizes routing, authentication, rate limits, and requests shaping for microservices. It excels at per-endpoint policies and usage analytics, and it often terminates Transport Layer Security (TLS). The risk lies in assuming those features double as DDoS controls. Without DDoS Testing, settings like burst limits, caching, and upstream retry behavior can fail under pressure or even amplify a flood, rather than mitigate it.
Load Balancer Basics
A load balancer distributes connections or requests across servers. In L4 mode, it balances TCP or UDP flows; in L7 mode, it inspects HTTP(S) and may perform SSL offload or header-based routing. Most load balancers include rate-limit and health-check features, but they are not purpose-built for DDoS mitigation. Configuration drift, auto-scaling thresholds, or timeout quirks can leave gaps you only find with DDoS Testing in production conditions.
Quick Comparison Table
| Control | Primary Role | Where DDoS Gaps Hide | What DDoS Testing Validates |
| API Gateway (L7) | Policy, auth, routing, quotas | Burst handling, token validation under load, cache behavior | Resilience to Layer 7 floods, per-endpoint limits, auth latency under pressure |
| Load Balancer (L4/L7) | Traffic distribution, failover, SSL offload | SYN/UDP attacks, connection table exhaustion, slowloris, timeout edges | Stability of connection handling, queue depth, failover behavior under stress |
| Shared | Availability and scale | DNS and upstream dependencies, misaligned thresholds | End-to-end availability under realistic attack mix |
Shared DDoS Blind Spots
- Volumetric floods that saturate upstream links before traffic even reaches the API gateway or load balancer.
- Layer 7 bursts that slip past CDN caches and hammer dynamic endpoints.
- DNS reflection and amplification attacks that spike packets-per-second (PPS) rates at the network edge.
- Auto-scaling race conditions, where new instances launch too slowly to stabilize load.
- Configuration drift across vendors and regions that erodes mitigations over time.
Closing the Gap with Continuous DDoS Testing
RADAR™ by Mazebolt validates every deployed layer – gateway, load balancer, WAF, scrubbing center, and CPE – with nondisruptive DDoS Testing on live production services. It runs continuously and nondisruptively, so you can identify DDoS misconfigurations without needing maintenance windows.
RADAR integrates with existing DDoS protections and produces audit-ready reports that track reduced risk exposure and improved, automated mitigation across OSI layers.
The Continuous DDoS Testing Cycle
- Map all public-facing services, API endpoints, and upstreams across OSI layers.
- Test continuously with nondisruptive DDoS simulation across L3/L4/L7 vectors.
- Identify DDoS vulnerabilities and misconfigurations in gateways, load balancers, and mitigations.
- Prioritize fixes by business impact and risk to critical services.
- Remediate with vendor-specific steps and confirm automated policies are optimized.
- Validate again to ensure vulnerabilities don’t return.
Compliance Lens – Global Rules Expect Proof, Not Promises
Around the world, cybersecurity regulations are shifting from trust-based claims to evidence-based accountability – requiring organizations to prove that their controls actually work under pressure. As of January 17, 2025, financial entities and any company operating in the EU are subject to the Digital Operational Resilience Act (DORA), which mandates robust ICT resilience and continuous testing across organizations and their critical third-party providers.The NIS2 Directive also applies to organizations operating in the EU. NIS2 technical guidance in 2025 details evidence organizations should produce to show that controls work in practice – including resilience for network and digital providers.
In the US, SEC rules require public companies to disclose material cyber incidents on Form 8-K Item 1.05 within four business days of determining materiality, which raises the bar for board-level readiness and documentation. NIST CSF 2.0 further formalizes continuous risk management and outcome-driven metrics that map cleanly to ongoing DDoS Testing.
UK and Canada echo the same resilience theme, reinforcing that availability is a global obligation, not just a regional one. RADAR’s automated, nondisruptive approach produces the kind of evidence these frameworks expect.
Key KPIs to Track – Residual PPS/BPS, TTM
To prove DDoS readiness across API gateways and load balancers, it’s essential to use clear, repeatable DDoS Testing metrics.
| KPI | What It Shows | Why It Matters |
| Time to Mitigate (TTM) | Seconds from first packet to stable bandwidth | Ensures automated mitigations trigger fast enough for SLAs |
| Residual PPS/BPS | Packets or bits hitting origin during an attack | Verifies scrubbing, gateway, and balancer policies actually block floods |
| False-Positive Rate | Legitimate traffic blocked by policies | Protects customer experience and revenue |
| Retest Pass Rate | Fixes that stayed fixed over time | Demonstrates drift control and continuous prevention |
Takeaways & Next Steps
API gateways and load balancers are essential to service availability, but they are not DDoS strategies by themselves. Continuous, nondisruptive DDoS testing closes the vulnerability gap by validating real behavior in live production environments, catching drift, and proving compliance using hard evidence. Explore the RADAR Continuous DDoS Testing tool to validate your gateways and load balancers and keep downtime off the balance sheet.
FAQ Snippet
Q1: Does RADAR DDoS Testing disrupt production services?
A: No. RADAR uses a patented, nondisruptive technique on the live production environment to validate deployed DDoS protections without impacting user services. [Case Study / Project File: PowerPoint Presentation- June 2025]
Q2: We already have premium DDoS mitigation. Why test?
A: Policy drift, new attack vectors, and dependency changes create blind spots over time. Continuous DDoS testing verifies that automated DDoS mitigations are working when you need them most – during a DDoS attack.
Q3: How does RADAR align to Gartner® CTEM?
A: The RADAR Map-Test-Identify-Prioritize-Remediate-Validate loop mirrors CTEM’s rolling phases and produces business-ready evidence. [Case Study / Project File: DDoS Testing: The Continuous, Nondisruptive Path to Gartner CTEM – FINAL- 2025]
Q4: What types of DDoS attacks (vectors) should we simulate when testing APIs?
A: Use a combination of:
- Layer 3/4 (L3/L4) volumetric floods – like SYN floods or UDP floods, to test network and transport-level resilience.
- Targeted Layer 7 (L7) bursts – such as HTTP floods hitting specific API endpoints, to mimic real-world app-level abuse.
- DNS amplification attacks – to simulate upstream traffic overloads.
- Authentication-heavy API endpoints – to stress-test how APIs handle login/token validation under pressure.
This mix reflects the real risk profile APIs face — affecting both API gateways and load balancers that manage traffic routing and security.
Q5: What proof do auditors expect?
A: Consistent KPIs like Residual PPS/BPS and TTM, plus retest evidence that fixes persist, mapped to NIST CSF 2.0 and EU rules like DORA.
Skim Outline
- Gateways and balancers need real DDoS validation.
- Continuous, nondisruptive DDoS tests expose hidden gaps.
- Global rules demand proof, not promises.
- KPIs show readiness and prevent
