Fukuoka University Preemptively Protects Entire Campus Network with Infoblox Threat Defense™

THE CHALLENGES

Securing an Expansive and Unmanaged Frontier

For Fukuoka University, the adoption of Infoblox NIOS DDI successfully stabilized core network management by replacing manual, command-line tasks with an intuitive graphical user interface (GUI) and automated processes. This transition virtually eliminated operational errors, providing the team with a reliable, standardized baseline for DNS, DHCP and IP address management (DDI).

However, this newfound stability was tested by a rapidly expanding digital footprint that today encompasses 420 network switches and 650 wireless access points, creating a high-density environment capable of handling 30,000 simultaneous connections. By 2020, the team recognized that the widespread adoption of bring-your-own-device (BYOD) terminals and guest access had rendered traditional security models obsolete. This effectively borderless network of unmanaged hardware and diverse operating systems created persistent blind spots that were beyond the reach of legacy tools.

With nearly 28,000 users on campus, security models, like endpoint detection and response (EDR) or network detection and response (NDR), were economically and operationally impossible to deploy. “Licensing for that many people is simply not feasible; we couldn’t afford it,” says Fujimura. “Besides, unless we made it a requirement for network access, it wouldn’t be effective.” The university needed a way to see and stop critical threats earlier without touching the client side.

THE SOLUTION

A Foundation of Visibility and Automated Defense

Fujimura and the network team realized that the most effective way to improve campus network resilience and protect 28,000 users was to secure the one thing every device has in common: the DNS layer.

The university added Infoblox Threat Defense™, a Protective DNS solution, to its existing Infoblox DNS infrastructure, establishing a foundational security layer that intercepts malicious activity at the very first stage of a connection— before an attack can even reach the network. The solution automatically blocks access to phishing sites, fake domains, malware distribution sites and command-and-control (C2) servers by denying DNS resolution to known malicious destinations.

Alongside Protective DNS, the university implemented Outbound Port 53 Blocking (OP53B) to prevent users and applications from bypassing authorized DNS services by sending queries directly to external DNS servers. As a result, every DNS request is routed through the university’s Infoblox infrastructure, where it is inspected and subject to consistent security policies across both managed and unmanaged devices alike. Centralizing DNS resolution also eliminated the “shadow” communications paths used by modern applications and malware to evade defenses, giving the network team visibility into traffic that was previously hidden and eliminating a very real blind spot for network teams.

Fukuoka further strengthened the integrity of its DNS infrastructure through Domain Name System Security Extensions (DNSSEC), which uses digital signatures to validate DNS responses and helps ensure users are directed only to legitimate destinations. This additional layer of protection helps mitigate the risk of digital tampering, such as DNS cache poisoning. Together, these capabilities provide a resilient foundation for campus-wide network security.

By shifting protection to the DNS layer, the university gained earlier visibility into threats while preventing malicious connections before they reach user devices, all without deploying additional software to thousands of student and faculty endpoints. “Everyone has to use DNS, and we don’t have to change anything on the client side for students and others,” explains Fujimura. “In terms of cost-effectiveness and ease of deployment, it was the most efficient approach.”

THE RESULT

Robust Security without Compromising Performance

Consolidating NIOS DDI and Threat Defense on a single Infoblox platform delivered immediate operational benefits. The “frequent” errors of the BIND era have completely vanished while previously complex tasks, like key security rollouts and DNSSEC updates, are now fully automated. Seiichirou Hiraoka of NTT West, the university’s technical team, estimates that Infoblox automation saves the university 120 to 170 hours annually on DNS management alone.

The security impact is equally significant. In a single month, Protective DNS blocked more than 34 million name resolution attempts, the majority associated with unauthorized DNS over HTTPS (DoH) traffic. By preventing DoH from circumventing the university’s authorized DNS infrastructure, the team maintains centralized visibility and control over DNS activity. Protective DNS also continues to detect and block malicious activity, including connections to malware distribution sites and C2 infrastructure.

This enhanced visibility allows the team to understand broader network-wide trends while identifying risks at the individual device level. During one sampling period, the university identified 256 IP addresses engaged in potentially malicious non-DoH activity, enabling the team to prioritize investigations and focus limited resources on the highest-risk endpoints. “Having Infoblox in place means we can detect threats before they even happen,” says Hiraoka. “It’s been a very easy solution to implement and maintain. Even with a large number of users, the cost and operational overhead are minimal.”

Crucially, the university has strengthened its security posture without compromising the user experience. Despite enforcing stricter controls over unauthorized DNS communication, the IT team has received zero complaints from students or staff. For Fujimura, that seamless experience is what ultimately matters: “Thanks to Infoblox, our education, research and medical services are operating smoothly and without interruption.”