Palo Alto Networks SD-WAN-Engineer Exam - Topic 4 Question 7 Discussion

Comprehensive and Detailed Explanation

This behavior describes the 'Best Available Path' logic inherent in Prisma SD-WAN's availability design.

SLA Thresholds: Path Quality Profiles act as filters to identify compliant paths.

Total Violation: If all configured 'Active' paths violate the SLA (e.g., Path A has 2% loss, Path B has 5% loss, and the threshold is 1%), the system does not drop the traffic (Option A) because maintaining connectivity is prioritized over perfect quality.

Selection Logic: The system enters a fallback state where it compares the available active paths and selects the 'Least Bad' one---the path that is closest to meeting the SLA (in this case, Path A with 2% loss).

Backup Paths: Traffic would only move to a Backup path (Option D) if the policy explicitly configures the backup path to engage upon SLA violation of the active set. However, strictly speaking, if only active paths are considered and all fail, it picks the best of the active group rather than blackholing the traffic.