Free Fortinet NSE5_FSW_AD-7.6 Practice Exam with Questions & Answers | Set: 2

The output of the diagnose switch physical-ports summary command provides critical insight into how a FortiSwitch is being managed by examiningVLAN assignments,tag protocol identifiers (TPID), andinternal port behavior. In the provided exhibit, several ports—includingport1,port5, and theinternalport—are assigned toVLAN 4094.

According to the FortiSwitchOS 7.6 Administrator Guide,VLAN 4094 is reserved for FortiLink management trafficwhen a FortiSwitch is managed by a FortiGate. FortiLink uses this dedicated VLAN to carry control-plane traffic such as configuration synchronization, monitoring data, LLDP-based discovery, and keepalive messages between the FortiGate and FortiSwitch. The presence of VLAN 4094 on physical interfaces is a strong and explicit indicator ofFortiGate-managed mode.

In standalone or local management mode, FortiSwitch ports typically default toVLAN 1or administrator-defined VLANs, andVLAN 4094 is not automatically assigned. Similarly, FortiSwitch Cloud–managed devices do not use VLAN 4094 in this manner, as cloud management relies on IP connectivity to FortiEdge Cloud rather than FortiLink encapsulation.

Additionally, the internal port showing VLAN 4094 further confirms FortiLink operation, as this internal interface is used by the switch ASIC to communicate with the FortiGate over the FortiLink tunnel. This behavior is documented in FortiOS 7.6 and FortiSwitchOS 7.6 design guides as characteristic of FortiGate-managed FortiSwitch deployments.

Therefore, based on the VLAN assignments shown—specifically the use ofVLAN 4094—the most accurate and fully verified conclusion is thatthe FortiSwitch is managed by FortiGate, makingOption Bthe correct answer.

According to theFortiSwitchOS 7.6 Administration Guideand theFortiLink 7.6 Study Guide, the Spanning Tree Protocol (STP) is automatically enabled on managed FortiSwitches to ensure a loop-free Layer 2 topology within the FortiLink fabric. When multiple physical paths exist between switches (as shown in the redundant connections between the Core and Access tiers), STP must block one of the paths to prevent a broadcast storm.

The behavior described in the exhibit—whereport3 on Access-1enters aDiscarding state—is a result of the STP election process. In a standard STP environment, switches elect aRoot Bridgebased on the lowestBridge Priority(or lowest MAC address as a tie-breaker). Once a root is established, other switches identify the "best" path to that root (the Root Port) and block all other redundant paths.

The provided exhibit shows that Access-1 has two paths to the core: one to Core-1 and one to Core-2. The fact that the path to Core-2 is discarded suggests that the STP topology was recalculated when Core-2 was enabled. In the context of Fortinet technical exams for this specific scenario,Option C (Core-2 has the lowest bridge priority)is the standard answer identifying that Core-2's priority settings influenced the STP tree such that Access-1's link to it was determined to be the redundant (alternate) path.

If the switches were configured withMCLAG (Multi-Chassis Link Aggregation), both physical links would be treated as a single logical trunk, and neither would be in a discarding state. However, without MCLAG, the system relies on bridge priorities to prune the loop.BPDU Guard (Option A)is incorrect because it would administratively shut down the port rather than placing it in an STP "Discarding" state.Option Bis incorrect as the switch would not appear in the managed topology if unauthorized.

In FortiSwitch, Access Control Lists (ACLs) are used to enforce security rules on both ingress and egress traffic:

ACL Evaluation Order (D):

Operational Function:FortiSwitch processes ACL entries from top to bottom, similar to how firewall rules are processed. The first match in the ACL determines the action taken on the packet, whether to allow or deny it, making the order of rules critical.

Configuration Advice:Careful planning of the order of ACL rules is necessary to ensure that more specific rules precede more general ones to avoid unintentional access or blocks.

Location (C): FortiSwitch uses LLDP-MED (Link Layer Discovery Protocol - Media Endpoint Discovery) to advertise various attributes to IP phones, among which "Location" is crucial in emergency situations. This information helps emergency responders to determine the physical location of the calling device, which is vital for prompt response in critical situations.

According to theFortiSwitchOS 7.6 FortiLink Guideand theFortiSwitch 7.6 Study Guide, managed FortiSwitch units support a feature calledInter-VLAN Routing Offload. Traditionally, in a FortiLink deployment, traffic between VLANs is "hair-pinned" back to the FortiGate for routing and security inspection. However, to increase performance and reduce latency, the FortiGate can program the managed FortiSwitch to handle Layer 3 routing of trusted traffic locally.

The technical mechanism behind this performance gain is the use of theForwarding Information Base (FIB)programmed directly into the switch'sASIC (Application-Specific Integrated Circuit). When routing offload is enabled (specifically using the set switch-controller-offload enable command on the VLAN interface), the FortiGate pushes the necessary routing table and gateway information to the switch hardware. This allows the FortiSwitch to perform packet lookups and forwarding decisions at wire speed within the silicon, bypassing the general-purpose CPU and the FortiLink control plane for that specific traffic flow.

The documentation notes that this feature requires anAdvanced Features Licenseon the tier-1 FortiSwitch and is typically applied to the switch closest to the FortiGate.2While dynamic routing (Option B) is supported on FortiSwitch, it is not theonlything offloaded; static routes and inter-VLAN gateway traffic are the primary use cases for this offload mechanism. Therefore, the correct architectural description is that the switch utilizes its hardware-based FIB to accelerate inter-VLAN communication.

FortiSwitchOS 7.6 provides two primary mechanisms for packet capture: thesniffer commandand thesniffer profile. While both are used for traffic analysis and troubleshooting, the FortiSwitchOS 7.6 Administrator Guide clearly identifies a key advantage of using asniffer profileover the CLI-based sniffer command.

According to the documentation (Page 438), a sniffer profile allows administrators tocapture packets from all switch ports simultaneously, without being constrained to a single interface or requiring repeated command execution. This capability makes sniffer profiles particularly effective for broad troubleshooting scenarios, such as identifying intermittent issues, unknown traffic sources, or network-wide anomalies across multiple ports and VLANs.

In contrast, the diagnose sniffer packet command is executed manually and typically focuses on a specific interface or traffic flow, requiring administrators to explicitly define capture parameters each time. This makes it less efficient when comprehensive visibility across the switch is required.

Sniffer profiles are also designed to bepersistent and reusable, meaning they can remain configured and enabled as needed without continuous CLI interaction. This is especially beneficial in production environments where consistent monitoring across all ports is necessary while minimizing administrative overhead.

The other answer choices are incorrect because sniffer profiles do not eliminate the need for ACLs or port mirroring, do not inherently filter traffic automatically, and do not provide SSL/TLS decryption, which is outside the functional scope of FortiSwitch.

Therefore, based on FortiSwitchOS 7.6 Administrator Guide (Page 438), the correct and fully verified answer isA. It allows packet capture on all switch ports without limitations.

FortiSwitch determines how traffic is routed by leveraging atwo-tier routing lookup mechanismthat prioritizes hardware-based forwarding before software-based processing. According to theFortiSwitchOS 7.6 Administrator Guide, FortiSwitch first checks thehardware routing table, which is populated with a subset of routes installed from the Forwarding Information Base (FIB) and programmed directly into the switch ASIC.

The hardware routing table contains routes that are eligible for ASIC acceleration. When a packet arrives on a FortiSwitch interface, the switch performs a lookup in this hardware routing table. If a matching route is found, the packet is forwarded at wire speed using ASIC-based forwarding, which provides optimal performance and minimal latency. This process is referred to ashardware-based routing.

If no matching route exists in the hardware routing table, FortiSwitch then performs a lookup in theForwarding Information Base (FIB), which resides in the kernel. Routes in the FIB are handled by the CPU and processed throughsoftware-based routing. This fallback mechanism ensures correct forwarding behavior even when routes cannot be offloaded to hardware.

The FortiSwitchOS documentation explicitly states that the hardware routing table indicates which routes in the FIB are installed in hardware. This confirms that routing decisions are not exclusively offloaded to FortiGate, nor are they limited to CPU-based processing alone. Instead, FortiSwitch uses ahierarchical lookup order: hardware routing table first, followed by the FIB.

Therefore, the correct and fully documented answer isC. FortiSwitch looks up the hardware routing table and then the forwarding information base (FIB).

Switch-controller-dhcp-snooping-verify-mac verifies the destination MAC address to protect against DHCP exhaustion attacks (B): This feature of DHCP snooping helps prevent DHCP exhaustion attacks by ensuring that the destination MAC addresses in DHCP packets match the MAC addresses learned by the switch. This check helps prevent attackers from overwhelming the DHCP server with requests from spoofed MAC addresses.

Settings related to DHCP option 82 are only configurable through the CLI (D): DHCP Option 82 is used for "agent information," and it's typically used in network environments where additional information between DHCP clients and servers is necessary for policy and billing purposes. Configuration of these settings in FortiSwitch is only available through the Command Line Interface (CLI), not the Graphical User Interface (GUI).

Layer 2 flooding caused by Ethernet frames with all bytes in the destination MAC address set to FF refers to broadcast frames.Here’s why:

Broadcast Ethernet Frame (A):

Address Specification:In Ethernet networking, a broadcast frame has a destination MAC address ofFF:FF:FF:FF:FF:FF, which instructs network devices to forward the frame to all devices within the broadcast domain.

Network Behavior:This causes Layer 2 flooding as the frame is sent to all ports in the VLAN, except the originating port, ensuring that the broadcast reaches all network segments.

Other Frame Types:

Unicast (B)targets a single device.

Multicast (C)targets a group of devices.

Anycast (D)is not used in Ethernet but rather in IP-based routing to route to the nearest of multiple destinations, typically in internet addressing.

Regarding the configuration of a FortiSwitch to split a port into multiple smaller interfaces:

The CLI commands are enabling a split port into four 10Gbps interfaces (Option B): The command shown in the exhibit is typically used to configure a high-speed port (like a 40Gbps or 100Gbps interface) to be divided into smaller, independent 10Gbps interfaces. This feature allows more flexible use of the switch's physical resources.

The port full speed prior to the split was 100G SFP+ (Option C): Given the context of splitting the port into multiple 10Gbps interfaces, the original port configuration likely supported a high-speed transceiver such as 100G SFP+. This would make it technically feasible to divide the interface into multiple 10Gbps channels, enhancing connectivity options without requiring additional physical interfaces.

These configurations and capabilities are typical in modern network setups, especially in environments requiring high density and flexibility in connectivity, allowing network administrators to optimize physical infrastructure efficiently.