SD-WAN Engineer Advanced Practice Exam: Hard Questions 2025

A global enterprise is designing Prisma SD-WAN for 300 branches. Each branch has two Internet circuits and must continue to pass local Internet traffic during a hub/DC outage. The security team also mandates that all SaaS traffic be steered to a cloud security service, while private application traffic must prefer the closest DC but fail over to an alternate DC with minimal disruption. Which architecture best satisfies these requirements with the fewest operational dependencies?

You are planning an SD-WAN rollout for remote sites where one underlay is broadband (frequent jitter) and the other is LTE (low bandwidth, metered). Voice and VDI must remain stable, but large software updates should never consume LTE unless broadband is down. Which design approach best balances performance and cost while maintaining deterministic behavior during brownouts (high loss/jitter but link not fully down)?

A customer must integrate SD-WAN with an existing routing design where branches advertise multiple internal prefixes toward the WAN edge, but the organization wants to avoid asymmetric routing when SD-WAN dynamically changes egress paths per application. Which approach most effectively preserves symmetry while still enabling application-aware path selection?

During deployment, a branch has two WAN circuits. The SD-WAN overlay comes up on both links, but application steering never uses the secondary link even when you intentionally degrade the primary. Path monitoring shows probes on the secondary are failing intermittently. Underlay reachability between branch and hub is confirmed. Which configuration issue is the MOST likely root cause?

A company needs to deploy a new SD-WAN site with strict change control. They want to stage the device, validate overlay reachability, and ensure the correct SD-WAN policy is attached before the site starts forwarding production traffic. Which method best reduces risk and avoids accidental traffic leaks during turn-up?

After onboarding a branch, users report that only certain SaaS applications are being steered to the cloud security service; others exit locally despite the intent policy stating 'all SaaS to security service'. Inspection shows those apps use QUIC/HTTP3 and sometimes appear as unknown-udp. What is the best corrective action to meet intent without overblocking legitimate traffic?

Operations notices that SD-WAN constantly flips paths for a critical ERP app at several branches, even though users report only occasional mild latency spikes. The policy uses aggressive thresholds and very short probe intervals. What is the best operational tuning to reduce instability while preserving user experience protection?

A network team wants to validate that SD-WAN policy changes are improving outcomes for voice quality across regions. They need to prove whether improvements come from better path selection versus unrelated ISP improvements. Which approach provides the most defensible operational evidence?

A branch shows intermittent one-way audio on VoIP calls after an SD-WAN policy update. Bidirectional overlays are up, but packet captures show RTP egressing via WAN1 while return RTP arrives on WAN2. Firewall sessions are being created on different egress interfaces over time. Which is the MOST likely cause and best fix?

A company integrates SD-WAN with a SASE/cloud security service for Internet egress. After rollout, several branches intermittently fail to reach SaaS apps only when steered to the security service; local breakout works. Logs show the security tunnel is up, but traffic to large SaaS providers times out more frequently during peak hours. Which troubleshooting step is MOST likely to identify the root cause quickly?