The senior security administrator wants to redesign the company DMZ to minimize the risks associated with both external and internal threats. The DMZ design must support security in depth, change…

A dual firewall DMZ places two distinct security boundaries between external and internal networks, satisfying the security-in-depth requirement by forcing an attacker to bypass two independently managed devices. Remote logging to a separate system ensures log integrity for incident reconstruction, since logs cannot be altered if the DMZ is compromised. Assigning a separate administrator to each firewall enforces separation of duties, directly supporting change management and configuration control processes.

A single firewall DMZ represents a single point of failure and does not provide security in depth, because compromising one device exposes both internal and external zones simultaneously.

A SaaS-based firewall introduces dependency on a third-party provider for a critical security control, which undermines internal change management processes and can complicate incident reconstruction due to limited or delayed log access.

A virtualized firewall running on a single physical host creates a single point of failure at the hardware layer, meaning a physical compromise or failure defeats all virtual instances and does not truly provide security in depth.