LEARN. PRACTICE. GROW.Concept and mechanism
CCNP Enterprise requires a core exam and an eligible concentration. This course begins with the six ENCOR v1.2 domains rather than every concentration in full. Architecture separates functions a dashboard view can conflate. In Catalyst SD-WAN, Manager handles management, Controller participates in control, Validator handles orchestration, and WAN edges operate the data plane. In SD-Access, LISP supports control, VXLAN encapsulated transport, and TrustSec policy. This separation helps form hypotheses: losing management access does not automatically demonstrate interruption of every flow, and observing an existing flow does not prove every control capability is healthy.
Guided application
In a fictional design, two circuits share a duct and two routers each support six hundred megabits per second. Critical load is eight hundred fifty. Normal combined capacity suffices, but losing one router leaves a two-hundred-fifty deficit; the duct remains a shared failure domain. Compare collapsed-core and three-tier designs through required scale, maintenance, and isolation. QoS does not create physical capacity. Policing can drop bursts despite a low long-term average; shaping can reduce that effect while introducing queue waiting. Measure application tradeoffs and timing distribution instead of selecting a policy only by name. Architecture acceptance should include what remains functional during failure and maintenance.
Two 600-Mb/s devices cannot sustain 850 Mb/s after losing one.
Common pitfalls
Distinct contracts as physical diversity; active traffic as healthy management; QoS as added capacity.
Related topics: Virtualization, VRFs, and overlays · Switching and adjacency formation · Routing and IP services
Design and accept service under degraded conditions too.
Reference: Financial vertical SD-Access and SD-WAN validated profile · 350-401 ENCOR v1.2, effective 2026-03-19; core component of CCNP Enterprise