What Is Network Segmentation?

Network segmentation helps organizations break complex infrastructures into smaller, controlled areas. Segmentation emerged as a security practice, but today it’s also essential to network performance, management, and scalability.

This article explains how network segmentation works, how it ties in with the zero trust approach, and the tools you can use to divide your network.

What is network segmentation, and how does it work?

Network segmentation is a cybersecurity practice that divides networks into small, isolated parts called segments. Each segment acts as a separate subnetwork with its own cybersecurity rules, workloads, users, applications, and devices.

The main goal of network segmentation is to reduce excessive connectivity.

In an unsegmented network, once attackers compromise one endpoint, they may be able to move laterally across systems and access sensitive assets. Segmentation limits this movement by placing boundaries between different environments. This can reduce the attack surface and make successful attacks less likely to affect the entire network.

Organizations use this practice to separate areas such as:

• Systems containing sensitive data 
• Development, testing, and production environments 
• Public and private networks 
• IoT and BYOD endpoints 

Key types of network segmentation

Network segmentation can be implemented in several ways depending on the organization’s technical means, network architecture flexibility, and goals. Organizations often combine several types of segmentation within one network.

From a technical perspective, segmentation is usually divided into physical and logical approaches.

Physical segmentation separates network areas using dedicated hardware, such as switches, routers, and network interfaces. This approach provides a high level of isolation but can be expensive and harder to scale compared to other types.

This type of segmentation is usually applied to:

• Critical infrastructure 
• Highly sensitive systems 
• Operational technology environments 
• Environments with strict regulatory or availability requirements 

Logical segmentation separates network traffic using software-defined or configuration-based controls. It’s more flexible than physical segmentation, as network engineers can create and adjust segments without rebuilding the physical layer. This makes it suitable for most enterprise environments where components change frequently.

From an architectural perspective, segmentation is often discussed as macrosegmentation or microsegmentation.

Macrosegmentation divides a network into broad security zones: production systems, guest networks, data centres, cloud workloads, etc. This approach helps reduce unnecessary connectivity between major parts of the organization and is often the first step toward a more controlled network architecture.

Microsegmentation works at a much deeper level. It defines granular policies for specific services, applications, or workflows. For example, a payment processing service can be allowed to communicate only with specific application components and databases, while all other traffic is blocked by default.

Benefits of network segmentation

The key benefits of segmenting a network are:

• Security incident localization. When an incident happens within a small segment of a network, it’s much harder for an attacker to move to other segments and affect more sensitive processes and data.
• Cybersecurity compliance. PCI DSS, NIST CSF, ISO 27001, and several cybersecurity frameworks recommend or rely on network segmentation controls to improve protection of sensitive systems and data. The goal here is improving data security for sensitive and financial records.
• Simplified network management. A small section of a network is easier to control than an entire organization’s infrastructure. Segmentation allows network engineers to tailor management tools to the needs of a specific segment: collect unique telemetry data, deploy additional monitoring tools, or simplify management overhead for the segments that don’t require high-level security.
• Improved network stability. Segmentation limits the range of network outages, incidents, and shutdowns due to maintenance and updates. Instead of affecting the entire network, these events are localized within one container.
• Network scalability and flexibility. Network engineers can copy, expand, upgrade, or disconnect specific segments of their network without affecting the whole network. Segmentation also allows them to enforce and edit policies for specific devices and resources quickly.

Network segmentation and zero trust

Network segmentation is an essential part of zero trust.

Zero trust is a cybersecurity approach based on the principle “never trust, always verify.” Instead of assuming that users, devices, or workloads inside the network are trustworthy, zero trust requires continuous authentication, authorization, and policy enforcement for every access request.

Network segmentation creates security boundaries that help enforce policies that define which systems can communicate, under what conditions, and for what purpose.

In particular, segmentation supports zero trust adoption by:

• Implementing strict controls for traffic movement within the network
• Helping to enforce the least privilege principle
• Making lateral movement difficult or impossible
• Enhancing network security mechanisms and making them more flexible

Network segmentation tools and controls

We already mentioned that network segmentation can be physical and logical. In the rest of this post, we’ll focus solely on logical segmentation tools and controls, as they don’t require additional hardware and physical network redesign.

There are six key ways to divide a network:

Improving network management with Apriorit

Building secure network management solutions is one of the key Apriorit’s domains.

We help companies ensure connectivity, performance, and protection of their networks by designing and delivering custom solutions.

When it comes to network segmentation, Apriorit can help with:

• Custom network management software development. We build solutions tailored to your infrastructure, security policies, and requirements.
• Network monitoring and observability. Our engineers can build a system that collects, processes, and visualizes traffic data across your network segments to detect misconfigurations, anomalies, and suspicious activity.
• Security-focused networking systems. We develop and improve tools for traffic inspection, filtering, firewall management, secure access, encryption, and policy enforcement.
• Software-defined networking. We help design flexible software-defined and cloud-ready networking solutions where segmentation policies can adapt to dynamic workloads and distributed environments.