The traffic from the user on Local-Client (10.0.1.10) pinging the IP address of Remote-FortiGate (10.200.3.1) will match the firewall policy with the service "PING traffic". According to the firewall policy:
* Policy ID 6 is set for PING traffic and uses the NAT IP pool "SNAT-Remote1", which is defined as
10.200.1.99.

The IPS sensor configuration shows that:
* The Microsoft.Windows.iSCSI.Target.DoS signature is set to "Monitor" with packet logging enabled, meaning that while traffic matching this signature will be allowed, it will also be logged for further analysis.
* The generic Windows filter is set to "Block," meaning that all other attacks matching this filter will be blocked. However, the sensor will not reset connections or log packets unless specified.
Therefore, the sensor will allow attackers matching the specific DoS signature while blocking other attacks against Windows.
References:
* FortiOS 7.4.1 Administration Guide: IPS Configuration

B. FortiGate will use the port1 route as the primary candidate.
FortiGate will use the port1 route as the primary candidate. It has better priority.

To configure redundant IPsec VPN tunnels on FortiGate with failover capability, the following two key configuration changes are required:
* A. Enable Dead Peer Detection (DPD): Dead Peer Detection is crucial for detecting if the remote peer is unreachable. By enabling DPD, FortiGate can quickly detect a dead tunnel, ensuring a faster failover to the secondary tunnel when the primary tunnel goes down.
* C. Configure a lower distance on the static route for the primary tunnel and a higher distance on the static route for the secondary tunnel: The static route with the lower distance (higher priority) will be used when both tunnels are operational. If the primary tunnel fails, the higher distance (lower priority) route for the secondary tunnel will take over, ensuring traffic is routed correctly.
The other options are not suitable:
* B. Enable Auto-negotiate and Autokey Keep Alive on the phase 2 configuration of both tunnels:
This option is not directly related to the requirements of failover between two IPsec VPN tunnels.
* D. Configure a higher distance on the static route for the primary tunnel and a lower distance on the static route for the secondary tunnel: This would prioritize the secondary tunnel over the primary tunnel, which is opposite to the desired configuration.
References
* FortiOS 7.4.1 Administration Guide - Configuring IPsec VPN, page 1320.
* FortiOS 7.4.1 Administration Guide - Redundant VPN Configuration, page 1335.

By default, DNS queries to FortiGuard servers use UDP port 53.