What is network segmentation?
Network segmentation means separating systems into different network zones so that access can be controlled and incidents are easier to contain.
Simple example
Guest Wi-Fi is separated from office computers, and servers are placed in a separate protected network.
Why it matters
Segmentation can limit how far an attacker or malware can move after one system is compromised.
Common warning signs
- The activity is unexpected or unusual for the business context.
- The request or system behaviour creates pressure to act quickly.
- Normal approval, verification, or security processes are bypassed.
- There are signs of unauthorised access, data exposure, or system change.
- Staff are unsure whether the request, message, or system behaviour is legitimate.
Cyber Doc view
This term should be understood in business context, not only as a technical issue. Good protection usually combines clear processes, appropriate technical controls, staff awareness, and a calm response plan.
What to do
Proactive steps
- Separate guest, staff, server, and management networks where practical.
- Limit access between network zones.
- Document which systems need to communicate.
- Use firewall rules between segments.
- Review segmentation after business changes.
Reactive steps
- Isolate affected network segments during an incident.
- Block unnecessary movement between systems.
- Review traffic logs between segments.
- Check whether other zones were reached.
- Strengthen segmentation after recovery.
Related terms
- Lateral movement
- Firewall
- Incident response