Network segmentation is the process of dividing a computer network into smaller, isolated segments or zones, each with its own access controls and security policies. This is done to reduce the attack surface and prevent lateral movement in case of a breach.

The network is typically segmented into the following zones:

1. Internet Zone: Externally facing systems and services, such as web servers and firewalls.
2. Demilitarized Zone (DMZ): Systems and services that require external access, but are not critical to internal operations, such as email and VPN servers.
3. Intranet Zone: Internal systems and services, such as file and print servers, and employee workstations.
4. Sensitive Data Zone: Systems and services that handle sensitive data, such as financial or personal information, such as databases and application servers.
5. Management Zone: Systems and services used for network management, such as network devices and monitoring tools.

The rationale behind segmentation is to:

• Reduce the attack surface by limiting access to sensitive areas of the network
• Prevent lateral movement in case of a breach
• Improve security and compliance by applying targeted security policies and access controls
• Enhance network visibility and monitoring
• Simplify network management and troubleshooting