You are configuring an SD-WAN rule to steer traffic to a business-critical application. The rule uses the 'Lowest Cost (SLA)' strategy with two members: a low-cost broadband link and an expensive MPLS link. The broadband link meets the SLA most of the time but occasionally experiences high latency. You want traffic to prefer the broadband link but fail over to MPLS when broadband violates the SLA. Which additional configuration is required to ensure the rule behaves as intended?
The 'Lowest Cost (SLA)' strategy selects the lowest-cost member that meets the SLA defined in an associated Performance SLA. Without a Performance SLA, the rule cannot determine SLA compliance, so it may always use the lowest-cost member regardless of latency. Creating a Performance SLA with appropriate thresholds and linking it to the rule ensures failover to MPLS when broadband violates the SLA.
Why this answer
The 'Lowest Cost (SLA)' strategy chooses the lowest-cost member that satisfies the SLA defined in a Performance SLA. The Performance SLA must be created separately and then referenced by the SD-WAN rule. Without it, the rule has no way to evaluate link health, so it may not fail over when the broadband link degrades.
Associating a Performance SLA with appropriate thresholds ensures the rule dynamically selects the MPLS link when broadband violates the SLA.
Exam trap
The trap here is assuming that the SD-WAN rule itself contains SLA thresholds, when in fact they are defined in a separate Performance SLA object.