Executive Summary
Modernizing Network Resilience
Before this project began, Illinois’ network security relied on a traditional perimeter centric
approach: a few central firewalls were expected to defend a large, aging, and increasingly
interconnected environment. Over time, the network grew more complex, with legacy
applications, cloud services, and high-volume interagency traffic creating visibility gaps that
perimeter tools simply couldn’t address. Once a threat actor slipped past the outer defenses, there
were limited internal controls to detect and prevent lateral movement.
This created a reactive security posture that struggled to keep up with modern threats,
inconsistent enforcement across systems, and recurring audit findings.
To address these challenges, the State of Illinois set a clear project goal: to enhance the overall
network security posture and simplify network complexity by decentralizing security enforcement.
Rather than depending on perimeter firewalls, the State of Illinois continued down the path to a
Zero Trust future by adopting a microsegmentation framework that enforces security policies
directly on each endpoint. This shift reduces lateral movement risks, increases internal traffic
observability, and creates consistent protection levels across both legacy and modern
environments.
With this objective, the Illinois Department of Innovation & Technology (DoIT) successfully
deployed microsegmentation controls across 3,000 servers, providing granular visibility and
control over roughly 550 million daily traffic flows. This marks a major evolution in Illinois’
cybersecurity approach and aligns with a core pillar of the state’s strategic security roadmap:
proactive risk mitigation.
