Network Segmentation

Simple Definition for Beginners:

Network segmentation is the practice of dividing a computer network into smaller, isolated segments or subnetworks to improve security, manage traffic flow, and enhance performance.

Common Use Example:

A company implements network segmentation to separate guest Wi-Fi traffic from internal network traffic, reducing the risk of unauthorized access to sensitive data and improving network performance for employees.

Technical Definition for Professionals:

Network segmentation involves partitioning a network into distinct segments or zones based on criteria such as user roles, applications, or security requirements. Key aspects of network segmentation include:

• Logical Segmentation:

o Divide the network logically using VLANs (Virtual Local Area Networks) or subnets to create isolated communication domains.

o Assign IP addresses, subnet masks, and routing rules to each segment to control traffic flow and communication between segments.

• Security Zones:

o Establish security zones or perimeters within the network, such as DMZ (Demilitarized Zone), internal LAN (Local Area Network), and guest networks.

o Implement firewall policies, access controls, and intrusion prevention systems (IPS) to enforce security policies between zones and protect critical assets.

• Access Control:

o Define access control policies based on user roles, device types, or authentication levels to restrict unauthorized access to sensitive resources.

o Use network access control (NAC) solutions to authenticate and authorize devices before granting network access, ensuring compliance with security policies.

• Traffic Segmentation:

o Segregate traffic types (e.g., data, voice, video) into separate segments to prioritize traffic, optimize bandwidth usage, and improve quality of service (QoS).

o Implement quality of service policies, traffic shaping, and prioritization mechanisms to manage bandwidth and reduce latency for critical applications.

• Isolation and Containment:

o Isolate critical systems, servers, or high-risk assets within dedicated segments to contain security incidents and limit the impact of breaches or malware outbreaks.

o Deploy network segmentation strategies like microsegmentation to granularly control communication flows between individual devices or services.

Network segmentation enhances network security by minimizing the attack surface, reducing lateral movement of threats, and providing better visibility and control over network traffic.