Network segmentation


Network segmentation in computer networking is the act or practice of splitting a computer network into subnetworks, each being a network segment. Advantages of such splitting are primarily for boosting performance and improving security.

Advantages

When a cyber-criminal gains unauthorized access to a network, segmentation or “zoning” can provide effective controls to limit further movement across the network. PCI-DSS, and similar standards, provide guidance on creating clear separation of data within the network, for example separating the network for Payment Card authorizations from those for Point-of-Service or customer wi-fi traffic. A sound security policy entails segmenting the network into multiple zones, with varying security requirements, and rigorously enforcing the policy on what is allowed to move from zone to zone.

Controlling visitor access

Finance and Human Resources typically need access via their own VLAN to their application servers because of the confidential nature of the information they process and store. Other groups of personnel may require their own segregated networks, such as server administrators, security administration, managers and executives.
Third parties are usually required to have their own segments, with different administration passwords to the main network, to avoid attacks via a compromised, less well protected, third party site.

Means of segregation

Segregation is typically achieved by a combination of firewalls and VLANs.
Software-Defined Networking can allow the creation and management of micro-segmented networks.