Authentic Fortinet Certification Exam NSE4_FGT_AD-7.6 Questions Answers

From the exhibits, there are three relevant firewall policies from LAN (port4) to WAN (port2), each using a different IP pool for source NAT:

TCP traffic

Service: ALL_TCP

Destination: BR1-FGT

IP Pool: SNAT-Pool → 100.65.0.49

PING traffic

Service: PING

Destination: all

IP Pool: SNAT-Remote1 → 100.65.0.99

IGMP traffic

Service: IGMP

Destination: all

IP Pool: SNAT-Remote → 100.65.0.149

The user on HQ-PC-1 (10.0.11.50) is pinging BR1-FGT (100.65.1.111). In FortiOS, policy matching is based on (among other fields) source, destination, and service, and the first matching policy in top-down order is applied.

Because the traffic is ICMP echo (ping), it matches the policy named PING traffic (service PING, destination all). That policy explicitly uses Use Dynamic IP Pool with SNAT-Remote1, which is configured with external IP 100.65.0.99.

Therefore, the source NAT IP used for this ping is 100.65.0.99.

According to the FortiOS 7.6 Troubleshooting and Administration guides, the diagnose debug flow command provides a step-by-step trace of how the FortiGate unit processes a packet.

First, the line "find a route: flag=00000000 gw-0.0.0.0 via port2" indicates that during the routing table lookup, the FortiGate matched the destination against its default route (represented by 0.0.0.0) and determined that the egress interface is port2. This confirms that the default gateway for this traffic is reachable via port2 (Statement A).

Second, the debug trace concludes with the messages "policy-2 Is matched, act-drop" and "Denied by forward policy check (policy 2)". This explicitly indicates that the packet successfully matched the criteria for firewall policy ID 2, and the action configured for that policy is set to Deny (Statement D).

Statement B is incorrect because a Reverse Path Forwarding (RPF) failure would be indicated by a specific "reverse path check fail, drop" message, which is absent here. Statement C is incorrect because the output shows "proto=1", which corresponds to ICMP (Ping) traffic. UDP traffic would be identified as protocol 17.

According to the FortiOS 7.6 High Availability (HA) Administration Guide and FGCP (FortiGate Clustering Protocol) requirements, the correct answers are B and D.

FGCP HA Cluster Mandatory Requirements (FortiOS 7.6)

When forming an HA cluster using FGCP, FortiGate devices must meet several strict compatibility and configuration requirements. Among the options given, the following two are mandatory:

✅ B. They must have the same number of configured VDOMs

In FortiOS HA, all cluster members must have the same VDOM configuration.

This includes:

Same number of VDOMs

Same VDOM names

This is required so configuration synchronization can occur correctly between members.

If VDOM counts differ, HA formation will fail.

✔ This is explicitly required and documented.

✅ D. They must have the same HA group ID

The HA group ID uniquely identifies an HA cluster on the network.

All FortiGate units intended to join the same cluster must share the same HA group ID.

If the group IDs differ, devices will not recognize each other as cluster peers.

✔ This is a fundamental FGCP requirement.

Why the Other Options Are Incorrect

❌ A. They must have the same hard drive configuration

Hard drive presence or size does not have to match for FGCP HA to function.

Disk differences may affect logging behavior, but they do not prevent HA cluster formation.

Therefore, this is not a required condition.

❌ C. They must have the heartbeat interfaces in the same subnet

Heartbeat interfaces must be:

Directly connected

In the same Layer 2 broadcast domain

They do not require IP addressing or being in the same IP subnet.

In many deployments, heartbeat interfaces have no IP addresses at all.

Therefore, “same subnet” is not a documented requirement.