Computer Basics - Network Segmentation

Network Segmentation is a cybersecurity practice where a larger network is divided into smaller, isolated sections (or segments) to control traffic flow, improve security, and limit the spread of threats.

Key Goals of Network Segmentation:

  • Containment: Prevents attackers or malware from moving laterally across the network.

  • Access Control: Ensures that users, devices, or applications can only reach what they’re authorized to.

  • Performance: Reduces unnecessary traffic on parts of the network, improving efficiency.

  • Compliance: Helps meet regulatory requirements (e.g., PCI DSS, HIPAA) by isolating sensitive data environments.

Common Approaches:

  1. Physical Segmentation:
    Using separate hardware (switches, routers, firewalls) to isolate traffic.

  2. Logical Segmentation:
    Implemented with technologies like VLANs, firewalls, or software-defined networking (SDN).

Examples:

  • Keeping guest Wi-Fi separate from the corporate LAN.

  • Isolating critical systems (e.g., financial databases, medical devices) from the general IT network.

  • Separating development/test environments from production.

Benefits:

  • Limits the blast radius of cyberattacks.

  • Simplifies monitoring and detection of suspicious activity.

  • Reduces risk of unauthorized access to sensitive resources.

Challenges:

  • Requires careful planning and maintenance.

  • Improper segmentation can lead to misconfigurations or operational complexity.