Network Segmentation

Network segmentation is a foundational security architecture principle that limits an attacker's ability to move freely across a network after initial compromise. By creating distinct network zones with controlled access points, organizations can enforce security policies tailored to the sensitivity and function of each segment.

Segmentation can be achieved through physical means such as separate switches and routers, or logically through VLANs, software-defined networking, and micro-segmentation technologies. Each approach offers different levels of granularity and management complexity. Micro-segmentation, in particular, provides fine-grained control at the workload level and is increasingly adopted in modern data center and cloud environments.

Effective segmentation requires careful planning around asset classification, data flow mapping, and access control policies. Critical systems like domain controllers, databases, and payment processing environments should reside in heavily restricted segments. Inter-segment traffic should be filtered through firewalls and monitored by intrusion detection systems. Regular audits ensure that segmentation rules remain effective as the network evolves.