Design lenses
What this lens evaluates Whether the design serves the business - its priorities, risk appetite, economics, and obligations - before any technology is chosen. The Practical brief leads with business intent; this lens is how you convert that intent into requirements and constraints that bound every later decision. The questions it forces
Design lenses
What this lens evaluates Whether each plane of the network is designed to scale, converge, fail gracefully, and be operated - and whether day-2 operations (monitoring, change, automation) are designed in, not bolted on. This is one of the heaviest domains in the blueprint. The questions it forces * Control plane:
Design lenses
What this lens evaluates Whether the topology delivers resilience, scalability, modularity, and clean addressing, converges fast enough, and can migrate from today's state - the structural heart of the design, and one of the largest domains. The questions it forces * Is the topology hierarchical/modular with bounded failure domains?
Design lenses
What this lens evaluates Whether the network delivers the specific services and applications the business runs - with the right QoS, multicast, network services, and segmentation - to meet application SLAs. The network exists to carry services; this lens keeps the design application-driven. The questions it forces * What are the application
Design lenses
What this lens evaluates Whether security is woven through every layer of the design - identity, segmentation, perimeter, hardening, and compliance - rather than bolted on at the edge. Security is risk- and compliance-driven, and it touches every other lens. The questions it forces * What is the threat model and the
Design lenses
Warning: These are tempting wrong answers Each trap below looks reasonable and is often the offered option a candidate reaches for first. The CCDE-correct move is in the fix. These patterns are distilled from worked practice scenarios and generalised (and AI-updated) - they are answer-selection discipline, not new