What is Network Segmentation?
Turkish: Ağ Segmentasyonu
Network segmentation separates users, servers, and systems into controlled network zones to limit unauthorized access and attack spread.
What is Network Segmentation?
Network segmentation divides an organization network into controlled zones instead of leaving it as one flat environment. Common segments include employee devices, servers, guest Wi-Fi, production systems, payment environments, and management networks.
An employee laptop should not be able to reach the accounting database, a camera network should not reach production servers, and guest Wi-Fi should not see internal systems. Segmentation creates these boundaries with VLANs, subnets, firewall rules, access lists, or software-defined network policies.
How it is Implemented
- VLANs and subnets: Separate traffic into logical network zones.
- Firewall rules: Decide which protocols and ports may cross between segments.
- DMZ: Keeps internet-facing services away from the internal network.
- Microsegmentation: Applies finer-grained policies at server or workload level.
- Identity-based access: Uses user, device health, and role context in access decisions.
Security Role
Segmentation does not prevent every compromise; it limits lateral movement after one device or account is affected. It reduces the blast radius of ransomware, stolen VPN credentials, and misconfigured services.
If firewall rules are too broad, segmentation only exists on diagrams. With zero trust, each network crossing becomes a separate trust decision. A mature implementation includes rule ownership, log monitoring, and regular access reviews.
Related Terms
A firewall filters traffic between devices and networks using rules, allowing approved connections while blocking suspicious or unauthorized access.
SubnetA subnet divides an IP address range into smaller network sections for routing, security boundaries, and address management.
VLANA VLAN separates devices into logical network groups on shared hardware, isolating traffic and tightening access control.
Zero Trust SecurityZero Trust continuously validates each user, device, and request by identity, context, and permission instead of trusting network location.