A systems engineer is designing a wide area network (WAN) environment for a new organization. The WAN will connect sites holding information at various levels of sensitivity, from publicly available…

Placing firewalls only around critical devices creates isolated islands of protection but ignores lateral movement threats and the interconnectedness requirement, leaving gaps between segments of varying sensitivity.

Layering technologies solely at the environment perimeter is a traditional perimeter-centric model that fails in a highly interconnected WAN where threats can originate from internal sites or traverse trusted inter-site links without crossing the external perimeter.

Reverse proxies and shadow environments are application-layer techniques designed for web-facing service protection, not for securing a multi-site WAN carrying data of varying classification levels across diverse business processes.

Aligning risk across all interconnected elements reflects a holistic, defense-in-depth security architecture that accounts for the reality that highly interconnected environments cannot rely on a single control boundary. By ensuring that risk assessments, threat detection, and response capabilities are consistently applied to every node and link in the WAN, critical threats can be identified and mitigated regardless of where they originate. This approach directly addresses the challenge of mixed-sensitivity sites sharing a common network fabric.