ELI5: What is Logical segmentation?

Instead of building actual walls, you use invisible lines on the floor to divide a room into sections. Logical segmentation uses software rules to split one network into separate zones without needing different physical cables.

Definition

Logical segmentation creates network boundaries using software-defined mechanisms rather than separate physical hardware. Technologies like VLANs, subnets, and software-defined networking (SDN) enable the creation of isolated network segments on shared physical infrastructure. Logical segmentation is more cost-effective and flexible than physical segmentation while providing meaningful security boundaries.

Key Details

  • VLANs: tag-based isolation at Layer 2; same physical switch can host multiple isolated VLANs
  • Subnets: Layer 3 boundaries that require routing between them; can enforce access control via ACLs
  • Software-defined networking (SDN): programmatic creation and management of network segments
  • Traffic between logical segments can be inspected and filtered by routers and firewalls
  • VLAN hopping attacks are a risk if VLAN configurations are not properly hardened

Connections