Network Segmentation

What is Network Segmentation?

Network Segmentation is a security practice that divides a network into smaller, isolated segments or zones. This approach improves security by limiting access between segments, reducing the attack surface, and containing potential breaches to prevent lateral movement by attackers.

Types of Segmentation

Macrosegmentation

• Department-based – Separate segments for HR, Finance, IT
• Function-based – Production, development, testing environments
• Data sensitivity – Public, internal, confidential, restricted zones
• User groups – Employees, contractors, guests

Microsegmentation

• Application-level – Individual applications or services
• User-level – Specific user or device access
• Workload-based – Virtual machines or containers
• API-level – Individual API endpoints

Implementation Methods

Physical Segmentation

• Air gaps – Complete physical separation
• Separate networks – Different hardware and cabling
• Dedicated infrastructure – Isolated servers and switches

Logical Segmentation

• VLANs – Virtual Local Area Networks
• Subnets – IP address-based separation
• Firewalls – Traffic filtering between segments
• Software-defined networking – Programmatic control

Benefits

• Containment – Limits the spread of malware and attacks
• Access Control – Restricts unauthorized access to sensitive areas
• Performance – Reduces network congestion and improves speed
• Compliance – Helps meet regulatory requirements
• Monitoring – Easier to detect and respond to threats

Best Practices

• Segment by data sensitivity – Isolate critical systems
• Apply least privilege – Only allow necessary communication
• Monitor inter-segment traffic – Log and analyze all connections
• Regular testing – Verify segmentation effectiveness
• Documentation – Maintain clear network architecture diagrams
• Automation – Use tools to enforce segmentation policies
• Regular reviews – Update segmentation as network evolves