Which two statements correctly describe what happens when traffic matches the implicit SD-WAN rule? (Choose two.)

When traffic does not match any explicitly configured SD-WAN rule, it is processed by the implicit SD-WAN rule (rule ID 0). The primary action of this rule is to forward the traffic using the standard routing table (FIB).

Consequently, the session is not associated with any user-defined SD-WAN service, which is what is meant by the session information displaying "no SD-WAN service id" (A).

Furthermore, the FortiOS order of operations dictates that policy routes are evaluated before SD-WAN rules. Therefore, for traffic to reach the SD-WAN rule evaluation stage and subsequently match the implicit rule, it must not have matched any entry in the policy route table (D).

B: This action is conditional. The implicit rule directs traffic to the FIB; ECMP is only used if multiple equal-cost routes to the destination exist in the FIB. It is not a guaranteed outcome.

C: This is incorrect. The implicit rule uses the best path(s) from the routing table, respecting administrative distance and metric. It does not simply use all available static routes regardless of their attributes.

E: The specific session flag vwldefault is not a documented flag in FortiOS for this behavior. While sessions may be flagged as maydirty, the combination with the non-standard vwldefault makes this option incorrect.

1. Fortinet FortiOS SD-WAN Architecture Guide 7.4.1

Page 11: "If traffic does not match any of the SD-WAN rules

it matches the implicit SD-WAN rule. The implicit rule forwards traffic based on the routing table." This supports the fallback mechanism and implies no specific SD-WAN service is applied (supporting A).

2. Fortinet FortiOS Handbook - Order of Operations 7.4.0

Page 7: This document outlines the packet flow

showing that "Policy-based routing" is checked before "SD-WAN." This confirms that for traffic to be evaluated by SD-WAN rules

it must not have matched a policy route (supporting D).

3. Fortinet FortiOS Handbook - Networking 7.4.0

Page 539: Describes Equal Cost Multi-Path (ECMP) routing. This section clarifies that ECMP is a function of the routing table when multiple equal-cost paths are available

confirming that its use is conditional

not absolute (refuting B).

4. Fortinet FortiOS CLI Reference 7.4.1

Page 1791 (diagnose sys sdwan session): The output for the implicit rule shows ruleid(0)

indicating it is tracked by an ID but corresponds to the default

non-service-specific rule (supporting the interpretation of A).