NSX Distributed Firewall as a Security Customs Network: A Practical Mental Model for East-West Zero Trust

This article presents a practical mental model for understanding VMware NSX Distributed Firewall (DFW) and microsegmentation, using the analogy of a security customs network. It emphasizes that workloads should not automatically trust each other based on network location; instead, connections should be evaluated based on identity, role, environment, destination, and policy. The article clarifies that DFW enforces policy close to workloads rather than centralizing traffic inspection. It covers key concepts like policy-based authorization, lateral movement prevention, and the shift from location-based to identity-based trust. This is valuable for IT professionals implementing Zero Trust security in virtualized data centers.