Microsegmentation: the unsung hero of cybersecurity (and why it should be your top priority)

Let’s talk about the most overlooked tool in cybersecurity: microsegmentation. It’s not a buzzword. It’s not a luxury. It’s the backbone of resilience — and it’s time we moved it from the margins to the center of our strategy.

Here’s the simplest way I explain it: Microsegmentation isn’t about blocking access. It’s about reducing the blast radius. If one laptop gets compromised, microsegmentation ensures the attacker can’t move laterally to critical systems. It’s the difference between a contained spark and a wildfire.

Think of your network like an apartment building. You’ve got a locked front door — that’s your perimeter. But once someone gets inside, there’s no front desk checking IDs, no elevator security and the same outdated lock on every unit. An intruder can roam freely, entering any apartment they choose. Microsegmentation is the internal security system. It’s the keycard for the elevator, the camera in the hallway, the unique lock on your door. It’s what stops one compromised device from becoming a full-blown breach.

Let’s revisit the OPM breach. It didn’t start at OPM; it started at DOI. Attackers gained access through a compromised laptop and moved laterally across the network. Had we implemented microsegmentation, they wouldn’t have gotten past that first system. It’s a powerful reminder that one weak link can compromise an entire ecosystem.

But here’s the catch: not all microsegmentation solutions are created equal. Most are designed for IT — data centers, cloud workloads and user devices. That’s important. But it’s not enough.

In Q1 2025, agencies faced 2,678 cyberattacks per week. Many targeted operational technology (OT) systems, like water treatment controls, earthquake sensors and drone fleets. According to Fortinet’s 2025 OT report, 50% of organizations experienced one or more intrusions last year and those with lower maturity levels suffered disproportionately.

And we’ve already seen the consequences from a recent takeover of a foreign military OT system where military drones were hijacked mid-flight and redirected to strike unintended targets. Now imagine that happening to unmanned U.S. DoD nuclear assets or Hoover Dam. The implications aren’t just technical; they’re geopolitical, with national security and citizen safety implications. Microsegmentation is one of the few tools that can protect both IT and OT environments, making it essential for national security.

OT environments are different. They’re often built on legacy systems, lack patching and operate in real-time. You can’t just drop an agent or reroute traffic without risking downtime. That’s why agencies need solutions that are agentless, software-defined and tailored to the unique constraints of OT. Otherwise, you’re only protecting half the house.

And it’s cost-effective. Security teams don’t have months to deploy or years to see value. With the right integrations, microsegmentation can be enforced in hours—not weeks—by reusing existing tools. It’s cheaper to operate, requiring no new agents, fewer consoles and less training overhead. 

That means less disruption and faster time to impact. It’s also stronger in practice, offering richer telemetry and automated containment when something goes wrong. And for agencies navigating complex mandates, it aligns with compliance frameworks like ISO 27001, SWIFT CSP, NIS2, DORA and Cyber Essentials, making reporting and audits far less painful.

Microsegmentation also plays a critical role in enabling zero trust. It enforces least privilege at the network level. It’s not just about who gets in; it’s about what they can touch once they’re inside. For agencies building toward zero trust, microsegmentation isn’t an afterthought. It’s a foundation.

Despite all this, microsegmentation remains underutilized. According to TechTarget’s Enterprise Strategy Group, only 36% of organizations use it today, even though it’s foundational to zero trust. Why? Because 28% believe it’s too complex. But that perception is often rooted in outdated tooling. 

We need to stop treating microsegmentation like an optional upgrade. It’s not a niche tool; it’s the lock on every door, the guard in every hallway and the difference between inconvenience and catastrophe. And for agencies facing budget constraints, legacy infrastructure and rising OT threats, it’s the smartest investment you can make.

Lou Eichenbaum is the Federal CTO at ColorTokens. He previously served as CISO at the Department of the Interior. This is the final piece in a three-part contributed series.