ELI5: What is Physical segmentation?
It’s like having completely separate buildings instead of just separate rooms. Physical segmentation uses different cables, switches, and hardware to keep network sections truly apart — no shared walls at all.
Definition
Physical segmentation creates network boundaries using completely separate physical hardware — different switches, cabling, and network infrastructure — for each network zone, rather than using logical separation on shared hardware. Physical segmentation provides the strongest isolation guarantee but is the most expensive and inflexible approach.
Key Details
- Separate physical switches, routers, and cabling for each network zone
- Traffic cannot cross between segments at Layer 2 — physical separation eliminates VLAN hopping risks
- Used for the most sensitive environments: classified government networks, payment processing, OT/ICS networks
- Very expensive: requires duplicate hardware and cabling for each segment
- Management complexity increases as the number of physically separate networks grows
Connections
- Parent: network-segmentation — physical segmentation provides the strongest network isolation
- See also: air-gap