www.example.com
This syntax targets the main domain, which is a common way to configure a web rating override for the home page of a website.
example.com
This syntax also correctly targets the main domain without specifying a subdomain (like "www"), which is valid for configuring a web rating override for the entire site, including the home page.

In this scenario, the FortiGate device is using a Virtual IP (VIP) to map the public IP address (203.0.113.2) to the internal IP address of the web server (172.16.1.10). The fact that the administrator does not see any sniffer output for incoming traffic suggests that the FortiGate is not responding to ARP requests for the public IP address (203.0.113.2).
Enabling arp-reply in the VIP configuration allows the FortiGate to respond to ARP requests for the public IP, thereby allowing traffic to reach the FortiGate, which will then forward it to the web server based on the VIP mapping.

When SSL certificate inspection is enabled on a FortiGate device, the system uses the following three pieces of information to identify the hostname of the SSL server:
* Server Name Indication (SNI) extension in the client hello message (B): The SNI is an extension in the client hello message of the SSL/TLS protocol. It indicates the hostname the client is attempting to connect to. This allows FortiGate to identify the server's hostname during the SSL handshake.
* Subject Alternative Name (SAN) field in the server certificate (C): The SAN field in the server certificate lists additional hostnames or IP addresses that the certificate is valid for. FortiGate inspects this field to confirm the identity of the server.
* Subject field in the server certificate (D): The Subject field contains the primary hostname or domain name for which the certificate was issued. FortiGate uses this information to match and validate the server's identity during SSL certificate inspection.
The other options are not used in SSL certificate inspection for hostname identification:
* Host field in the HTTP header (A): This is part of the HTTP request, not the SSL handshake, and is not used for SSL certificate inspection.
* Serial number in the server certificate (E): The serial number is used for certificate management and revocation, not for hostname identification.
References
* FortiOS 7.4.1 Administration Guide - SSL/SSH Inspection, page 1802.
* FortiOS 7.4.1 Administration Guide - Configuring SSL/SSH Inspection Profile, page 1799.

When SD-WAN is enabled on FortiGate, the load balancing algorithm for Equal-Cost Multi-Path (ECMP) is configured using the load-balance-mode parameter under SD-WAN settings. However, if SD-WAN is disabled, the ECMP load balancing algorithm can be configured under config system settings. This flexibility allows FortiGate to control traffic routing behavior based on the network configuration and requirements.
References:
* FortiOS 7.4.1 Administration Guide: ECMP Configuration

The Reverse Path Forwarding (RPF) check is run on the first sent packet of any new session to ensure that the packet arrives on a legitimate interface. This check protects the network from IP spoofing attacks by verifying that a return route exists from the receiving interface back to the source IP address. If the route is invalid or not found, the packet is discarded. Options B and C are incorrect because RPF checks are performed on the first sent packet, not the reply packet.
References:
* FortiOS 7.4.1 Administration Guide: Reverse Path Forwarding (RPF) Check