Zero Trust Security Network Segmentation
Network segmentation divides a large network into smaller, separate sections. Each section gets its own access rules and its own boundary checks. Zero Trust Security relies on segmentation to stop attackers from moving freely once they breach one part of a system.
What a Segment Actually Is
A segment groups related systems together, such as all finance servers or all customer databases. Traffic moving between segments must pass through a checkpoint, similar to traffic between countries crossing a border. Traffic moving within one segment still faces checks under a Zero Trust model, just at a smaller scale.
A Diagram of a Segmented Network
Finance Segment ⇄ Checkpoint ⇄ HR Segment ⇄ Checkpoint ⇄ Marketing Segment ⇄ Checkpoint ⇄ Public Website Segment
An attacker who breaks into the public website segment hits a checkpoint before reaching marketing files. That same attacker hits another checkpoint before reaching HR or finance data.
Layman's Example: The Apartment Building
A large apartment building gives each tenant a key that opens their own unit and shared common areas only. A tenant's key never opens a different tenant's apartment door, even within the same building. A burglar who steals one tenant's key gains access to one apartment, not the whole building. Network segmentation copies this same containment design for digital systems.
Microsegmentation: Going Smaller Still
Microsegmentation breaks a network into very small zones, sometimes down to single applications or servers. A payment processing server might sit in its own tiny segment, separate from everything else in finance. This extreme separation limits an attacker to one small box, even after breaching a larger segment first.
Benefits of Network Segmentation
- Slows attacker movement across a company network significantly
- Limits the spread of malware infections to a smaller area
- Makes unusual traffic between segments easier to spot and investigate
- Allows different security rules for different types of data
A Common Mistake With Segmentation
Some companies create segments but forget to monitor traffic crossing between them. A checkpoint without monitoring resembles a locked door without a guard nearby. Zero Trust Security pairs segmentation with constant traffic monitoring to catch suspicious crossings quickly.
Key Takeaways
- Segmentation divides a network into smaller, separately guarded sections.
- Microsegmentation pushes this idea down to individual applications or servers.
- Segmentation slows attackers and limits how far a single breach can spread.
- Monitoring traffic between segments matters as much as creating the segments.