Network Segmentation

Network Segmentation is the practice of dividing a computer network into smaller, isolated subnetworks to enhance security, improve performance, and reduce risk across IT, IoT, OT, and IoMT environments.

By separating devices, such as servers, workstations, medical devices, industrial controllers, and IoT endpoints, into distinct segments with controlled access policies, organizations can prevent lateral movement during cyberattacks, contain breaches, and manage network traffic more efficiently.

Network segmentation uses access control policies enforced through Network Access Control (NAC) solutions, firewalls, VLANs, and security group tags to restrict which devices can communicate with each other. Modern approaches include:

• Macro segmentation: Grouping devices by broad categories (e.g., medical devices, IT systems, OT assets)
• Microsegmentation: Creating granular policies for individual devices or small groups based on function, risk, and behavior
• Dynamic segmentation: Using identity-based controls (such as Security Group ACLs) that follow devices as they move across the network

Effective segmentation reduces an organization’s attack surface by limiting what compromised devices can access. It’s a critical component of zero trust architectures (ZTA) and helps organizations:

• Prevent ransomware and malware from spreading laterally
• Protect critical infrastructure and high-value assets
• Meet compliance requirements (HIPAA, NERC CIP, PCI-DSS, NIS2)
• Reduce the impact and cost of security incidents

Unlike traditional flat networks, where all devices can communicate freely, segmented networks create security boundaries that contain threats and reduce organizational risk.