Arista ACE Specialist - WAN Routing study plan

Map the WAN/SD-WAN architecture building blocks (underlay, overlay, control plane, data plane) and write a one-paragraph definition of each from memory

Compare hub-and-spoke, full-mesh, and partial-mesh topologies and list two tradeoffs for each

Diagram the packet walk for a spoke-to-spoke flow across an SD-WAN overlay, labeling every encapsulation and lookup

Define the role of path selection inputs (link quality, policy, priority) and where each is evaluated

Configure and verify at least two dynamic routing protocols in a lab and capture neighbor/adjacency state

Explain how a routing protocol's metric and administrative distance interact to choose a best path

Trace a route from RIB to FIB and identify the exact point where ECMP or path preference is decided

Predict the outcome of three convergence scenarios (link down, neighbor reset, metric change) before testing them

Describe how overlay tunnels are established, keyed, and kept alive, and list the failure modes of each step

Configure a basic overlay between two sites and verify tunnel state end to end

Identify which traffic is eligible for overlay steering versus underlay breakout and justify the split

Document the control-plane versus data-plane responsibilities in your lab overlay

Build a policy that steers a named application class over a preferred path and a fallback path

Test policy behavior when the preferred path degrades and confirm the fallback triggers

Explain the order of evaluation among match criteria, action, and default behavior

List three ways a misconfigured policy silently sends traffic the wrong way and how to detect each

Instrument your lab to capture per-path latency, loss, and jitter and correlate them with steering decisions

Configure alerting or logging for path-quality threshold crossings

Reconstruct a steering decision from telemetry alone, without reading the config

Write the exact command or query sequence you would use to prove why traffic took path A instead of path B

Build a triage checklist that separates underlay, overlay, control-plane, and policy faults

Inject three faults (tunnel down, policy mismatch, routing loop) and diagnose each within a time box

Practice reading logs and show commands to localize a fault to a single layer before changing config

Document rollback steps for each fault you injected

Design a multi-site WAN from a written requirements brief, choosing topology, routing, and failover

Defend each design choice against at least two alternatives in writing

Identify the observability gaps in your design and specify what you would monitor to close them

Estimate convergence and failover time for your design and state the assumptions behind the estimate

Run a full timed practice pass across all four domains and score it by domain

Re-drill your two weakest subtopics until you can explain them without notes

Rebuild your one-page summary of evaluation order, path selection inputs, and triage layers

Review every missed item and convert each into a flashcard or lab task