How should I segment my network?

Start by separating: corporate workstations from servers, guest Wi-Fi from internal networks, IoT devices from business systems, and payment systems from general networks. Group systems by function and data sensitivity. Control traffic between segments with firewall rules. As security matures, move toward micro-segmentation for more granular control.

What is micro-segmentation?

Micro-segmentation applies segmentation at the individual workload or application level rather than the network level. It uses software-defined policies to control communication between specific servers, containers, or applications. This provides much more granular control than VLAN segmentation and is a key component of Zero Trust architecture.

Does network segmentation affect performance?

Properly implemented segmentation can actually improve performance by reducing broadcast traffic within segments. The overhead of inter-segment routing is minimal with modern network equipment. The key is proper planning: ensure frequently communicating systems are in the same segment and that inter-segment bandwidth is sufficient for legitimate traffic.

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Network Segmentation

Also known as:network zoningnetwork isolationVLAN segmentation

The practice of dividing a computer network into smaller, isolated subnetworks to improve security, performance, and manageability by limiting the spread of threats and controlling traffic flow between segments.

In-Depth Explanation

Network segmentation divides a network into smaller, isolated segments with controlled communication between them. This limits an attacker's ability to move laterally through the network if they breach one segment, containing the damage of a security incident.

Segmentation approaches:

Physical segmentation: Separate physical network infrastructure for each segment
VLAN segmentation: Virtual LANs dividing the network logically on shared infrastructure
Subnet segmentation: Using IP subnets with router-enforced access controls
Micro-segmentation: Granular, software-defined segmentation at the workload level
Software-defined networking (SDN): Programmable network segmentation

Common network segments:

Corporate network: Standard employee workstations and devices
Server network: Application and database servers
Management network: Network management and administration systems
Guest network: Isolated network for visitors and personal devices
IoT network: Internet of Things devices (printers, cameras, sensors)
PCI network: Cardholder data environment (for payment processing)
DMZ: Demilitarised zone for public-facing services

Benefits of segmentation:

Limits lateral movement of attackers and malware
Reduces the blast radius of security incidents
Improves compliance posture (e.g., PCI-DSS scope reduction)
Enables granular access control and monitoring
Improves network performance by reducing broadcast traffic
Simplifies troubleshooting and management

Business Context

Without segmentation, an attacker who compromises one device can potentially access every system on the network. Segmentation is one of the most effective ways to limit the damage of a breach and is recommended by the ACSC and required by frameworks like PCI-DSS.

How Clever Ops Uses This

Clever Ops designs and implements network segmentation for Australian businesses, creating isolated zones for different functions and data sensitivity levels. We configure VLAN segmentation, firewall rules between segments, and monitoring to detect unauthorised cross-segment traffic.

Example Use Case

"An Australian retail business segments their network into corporate, POS, guest Wi-Fi, and IoT zones. When ransomware infects a workstation on the corporate network, segmentation prevents it from reaching the POS systems, protecting payment data."