DDoS Readiness Testing Strengthens a Global DNS Provider’s Infrastructure

As a major DNS provider managing and registering global top-level domains, our client's organisation carries a significant responsibility: keeping the internet running smoothly for millions of users. Before launching a newly enhanced infrastructure, they needed confidence that it could withstand real-world pressures, including heavy peak traffic and the threat of DNS-based DDoS attacks. 

The reputational and financial stakes were high. With so much depending on their performance, the DNS provider sought a controlled yet realistic test environment to validate the robustness of their investment and operational readiness. 

The Task

To gain that assurance, the organisation commissioned two 90-minute DDoS attack tests. After completing NDAs and commercial agreements, detailed technical consultations ensured everyone was aligned on what success needed to look like. 

Together, we defined: 

• Compliance requirements 
• Test objectives 
• Risk and systems assessments 
• DDoS attack types and parameters 
• Infrastructure behaviour under load 

With rate-limiting temporarily removed, the staging environment was prepared for authentic performance testing. 

The Test

On the test day, the provider’s key stakeholders joined a live conference session to observe the test portal and communicate directly with our engineering team. With an emergency stop mechanism in place, they remained fully in control throughout. 

The attack simulation included: 

• 500,000 DNS queries per second 
• Mix of UDP record lookups 
• Normal and DNSSec-based queries 
• Additional volumetric stress tests across different data centres 

This allowed the team to see exactly how latency, responsiveness and user experience changed under high-pressure scenarios. 

The Results

The system performed strongly, passing the majority of tests and highlighting only a few unexpected behaviours, all of which were promptly analysed using detailed debugging information. 

Crucially, the testing: 

• Validated the investment in the new infrastructure 
• Confirmed the system could withstand likely attack vectors 
• Provided clarity on load thresholds, mitigation performance and operational resilience