Which statement best describes the security benefit of network segmentation?

• A. Eliminates the need for firewalls
• B. Makes monitoring harder
• C. Reduces blast radius and limits lateral movement
• D. Increases attack surface

Answer: (C)

Dividing a network into smaller, isolated segments with tight controls between them helps contain breaches. The key benefit is that it reduces blast radius and limits lateral movement. If someone gains access to one segment, the security boundaries—such as firewalls, ACLs, VLANs, and micro-segmentation—restrict traffic so they can’t freely reach other parts of the network. This containment makes it harder for attackers to move sideways, limits what they can affect, and speeds up detection and response because inter-segment activity can be monitored and controlled more precisely.

The other statements aren’t correct because segmentation doesn’t eliminate the need for firewalls; it relies on them to enforce boundaries. It generally makes monitoring easier, not harder, since traffic between segments is a defined, measurable boundary. And segmentation reduces the attack surface by compartmentalizing assets, not increasing it.