According to the FortiGate / FortiOS 6.4.2 Administration Guide, the health check status command displays the status of the health check probes for each SD-WAN member interface. The output includes the following information:
* state: the current state of the interface, either alive or dead
* packet-loss: the percentage of packets lost during the health check
* latency: the average round-trip time in milliseconds
* jitter: the variation in latency
* mos: the mean opinion score, a measure of voice quality
* bandwidth: the available bandwidth in kilobits per second for each direction (up, down, bi)
* sla map: a bitmap that indicates which SLA criteria are met or failed Based on the exhibit, the following statements are correct:
* The health-check VPN_PING orders the members according to the lowest jitter. This means that the interface with the lowest jitter value is listed first, followed by the next lowest, and so on1. In the exhibit, the order is T_MPLS, T_INET_1, and T_INET_0.
* There is no SLA criteria configured for the health-check Level3_DNS. This means that the health check does not use any SLA parameters to determine the state of the interface2. In the exhibit, the sla map value is 0x0 for both port1 and port2, indicating that no SLA criteria are applied.

Based on the exhibit, the "corporate" zone contains no member (B). In the FortiGate GUI, zones without members do not display any interfaces listed under them, which is the case for the corporate zone in the exhibit. References: This conclusion is based on standard Fortinet GUI interpretation and the operational logic of SD-WAN zones as per Fortinet's guidelines and user interface standards.

SD-WAN zones are a group of interfaces that share the same SD-WAN settings, such as health check, SLA, and load balancing. Some characteristics of SD-WAN zones are:
An SD-WAN zone can contain different types of interfaces, such as physical, VLAN, aggregate, and tunnel interfaces1.
An SD-WAN zone can contain up to 512 members1.
You can use an SD-WAN zone in static route definitions, as long as the destination interface is also an SD-WAN zone1.
You can configure up to 32 SD-WAN zones per VDOM1.