CCNA Dc Storage Network Questions

75 of 154 questions · Page 1/3 · Dc Storage Network topic · Answers revealed

1
MCQeasy

A company wants to consolidate multiple physically separate Fibre Channel SANs into one switch infrastructure while keeping each SAN's traffic isolated. Which technology best achieves this?

A.Reduce the number of switches by using a single director
B.Virtual SANs (VSANs)
C.Use a single VSAN with extensive zoning
D.Deploy separate physical cabling for each SAN
AnswerB

VSANs create isolated logical fabrics over a physical infrastructure.

Why this answer

VSANs (Virtual SANs) allow multiple physically separate Fibre Channel SANs to be consolidated onto a single switch infrastructure by creating isolated virtual fabrics. Each VSAN maintains its own fabric services, such as name server and zone server, ensuring traffic isolation without requiring separate physical switches or cabling.

Exam trap

Cisco often tests the misconception that zoning alone provides the same isolation as VSANs, but zoning only controls device access within a single fabric, whereas VSANs provide complete fabric-level separation including separate control planes and fabric services.

How to eliminate wrong answers

Option A is wrong because reducing the number of switches by using a single director does not inherently isolate traffic; it simply consolidates hardware without providing logical separation. Option C is wrong because using a single VSAN with extensive zoning only controls which devices can communicate, but all traffic still shares the same fabric services and control plane, which can lead to instability and security risks. Option D is wrong because deploying separate physical cabling for each SAN defeats the purpose of consolidation and increases cost and complexity, whereas VSANs achieve isolation logically.

2
MCQhard

A large data center uses a Cisco Nexus 9000 switch with FCoE NPV feature. The switch is connected to an MDS 9700 upstream. The network team recently replaced the MDS 9700 with a new one. After the replacement, the FCoE hosts are unable to log in to the storage fabric. The Nexus switch shows that the FCoE NPV uplinks are up but no FLOGIs are being forwarded. The show npv flogi-table on the Nexus is empty. The upstream MDS shows that the uplinks are in VSAN 100, and the zoning is correct. The Nexus switch configuration includes 'feature npv' and 'npv enable' on the relevant interfaces. The FCoE VLAN 100 is mapped to VSAN 100. What is the most likely cause?

A.The upstream MDS is not configured to accept NPV connections
B.The FIP snooping policy is blocking the FLOGI traffic
C.The Nexus switch is missing the 'fcoe fka-adv-period' configuration
D.The FCoE hosts are not in the same VLAN as the FCoE NPV uplinks
AnswerA

The MDS needs NPIV enabled on the uplink interfaces to proxy FLOGIs from the Nexus.

Why this answer

The most likely cause is that the upstream MDS is not configured to accept NPV connections. For NPV to work, the upstream switch (MDS) must have NPIV enabled on the uplink interfaces. Without NPIV, the MDS will reject FLOGI requests from the Nexus.

Other options: FKA-adv-period affects keep-alives, not login; FIP snooping is on the Nexus but would not cause empty flogi-table if uplinks are up; VLAN mapping is correct.

3
MCQeasy

A network engineer is troubleshooting a slow backup performance between a backup server and a tape library connected via FC. The backup server is connected to a Cisco MDS switch at 8 Gbps, and the tape library is connected at 4 Gbps. The backup job is using hardware compression. Which factor is most likely limiting performance?

A.Port speed mismatch between the server and tape library
B.Insufficient buffer credits on the MDS switch
C.Hardware compression on the tape library
D.Half-duplex mode on the FC link
AnswerA

The slower device (4 Gbps) determines the link speed.

Why this answer

The backup server is connected at 8 Gbps while the tape library is connected at 4 Gbps. In Fibre Channel, the link speed is negotiated per port, and the end-to‑end flow is limited by the slowest link in the path. Even though the server can transmit at 8 Gbps, the tape library can only receive at 4 Gbps, creating a bottleneck that caps the backup throughput.

Hardware compression on the tape library does not cause this speed mismatch; it actually reduces the amount of data written to tape, but the physical link rate remains the limiting factor.

Exam trap

Cisco often tests the misconception that buffer credits are the primary cause of any FC performance issue, but here the persistent throughput limit is due to a static speed mismatch, not a dynamic credit starvation problem.

How to eliminate wrong answers

Option B is wrong because insufficient buffer credits typically cause frame drops and retransmissions under high load, not a consistent speed cap; the scenario describes a persistent throughput limit, not loss‑induced slowdown. Option C is wrong because hardware compression reduces the volume of data written to tape, which would improve backup performance, not limit it. Option D is wrong because Fibre Channel operates in full‑duplex mode by design; half‑duplex does not exist in FC standards (FC‑0 through FC‑4 all assume full‑duplex links).

4
MCQmedium

A large enterprise is deploying a new storage network for a VMware vSphere cluster with 200 VMs. The cluster uses vSphere 7 with vVols and requires a SAN that supports 16 Gbps FC. The storage team wants to use a Cisco MDS 9148S switch and has configured two VSANs: VSAN 100 for production and VSAN 200 for backup. The backup server is connected to VSAN 200. After the deployment, the backup administrator reports that backup jobs from the backup server to the storage array are failing. The storage array is connected to both VSANs via a single FC interface configured in 'auto' mode. The backup server is connected to an F-port in VSAN 200. The storage array's interface shows 'trunking' enabled and is in 'up' state. What is the most likely cause of the backup failure?

A.Configure the MDS switch interface connected to the storage array as a trunk port and ensure VSAN 200 is in the allowed list.
B.Move the backup server to VSAN 100 to match the production storage.
C.Change the storage array interface to 'F' mode to force it to be in a single VSAN.
D.Disable trunking on the storage array interface to prevent VSAN mismatch.
AnswerA

This allows the array to be in both VSANs and ensures the backup server can communicate with the array.

Why this answer

The storage array is connected to both VSANs via a single interface with trunking enabled, but the MDS switch interface connected to the array is not configured as a trunk port. Without trunking on the switch side, the interface can only belong to one VSAN (likely VSAN 100 by default), so traffic from the backup server in VSAN 200 cannot reach the storage array. Option A resolves this by configuring the switch interface as a trunk port and explicitly allowing VSAN 200 in the allowed VSAN list, enabling the array to communicate with both VSANs.

Exam trap

Cisco often tests the misconception that enabling trunking on the storage array alone is sufficient, when in fact both ends of the link must be configured as trunk ports for multi-VSAN traffic to pass.

How to eliminate wrong answers

Option B is wrong because moving the backup server to VSAN 100 would disrupt backup isolation and does not address the root cause—the switch interface is not trunking to carry VSAN 200 traffic. Option C is wrong because changing the storage array interface to 'F' mode would force it into a single VSAN, preventing it from serving both production and backup traffic, which is the opposite of what is needed. Option D is wrong because disabling trunking on the storage array interface would eliminate the ability to carry multiple VSANs, making the backup failure permanent; trunking is required to allow the single interface to participate in both VSANs.

5
Multi-Selecteasy

Which THREE of the following are required to configure FCoE NPV on a Cisco Nexus switch?

Select 3 answers
A.Enable FIP snooping.
B.Associate the FCoE VLAN with the VSAN.
C.Configure a storage VLAN.
D.Configure a VSAN for FCoE.
E.Enable FCoE on the switch.
AnswersA, B, E

FIP snooping prevents rogue FCoE devices.

Why this answer

FIP snooping is required on the NPV switch to inspect and validate FCoE Initialization Protocol (FIP) frames, preventing unauthorized FCoE devices from joining the fabric. Without FIP snooping, the NPV switch cannot properly forward FCoE traffic between the ENode and the upstream FCF, making it a mandatory configuration step for FCoE NPV.

Exam trap

Cisco often tests the distinction between configuring a VSAN on the NPV switch (which is incorrect) versus associating the FCoE VLAN with a VSAN (which is correct), leading candidates to mistakenly select 'Configure a VSAN for FCoE' as a required step.

6
Multi-Selecteasy

Which TWO commands are used to verify zoning configuration on a Cisco MDS switch? (Choose two.)

Select 2 answers
A.show zone
B.show fcns database
C.show flogi database
D.show vsan membership
E.show zoneset active
AnswersA, E

Displays all configured zones.

Why this answer

The 'show zone' command displays the configured zone database, including zone members and their aliases, which is essential for verifying zoning configuration. The 'show zoneset active' command shows the currently active zoneset that is enforced by the switch, confirming which zones are actually applied to traffic. Both commands directly verify zoning configuration on a Cisco MDS switch.

Exam trap

Cisco often tests the distinction between commands that show device login status (fcns, flogi) versus commands that show the actual zoning configuration (zone, zoneset active), leading candidates to mistakenly choose login-related commands as zoning verification tools.

7
MCQmedium

A storage administrator notices that a Fiber Channel link between a server and a Cisco MDS switch is flapping every few minutes. The server's HBA and the switch port are both configured for 16 Gbps. Which action is most likely to resolve the issue?

A.Increase the link timeout interval on the switch port
B.Replace the SFP module on the switch port with a compatible Cisco SFP
C.Configure the switch port speed to auto-negotiate
D.Change the admin state of the interface to shut and no shut
AnswerB

Faulty SFP is a common cause of link flapping.

Why this answer

Option C is correct because the most common cause of link flapping is an incompatible or faulty SFP. Replacing it with a compatible, genuine Cisco SFP resolves the issue. Option A is wrong because changing the admin state does not address the physical layer problem.

Option B is wrong because increasing the timeout may mask the flapping but not fix it. Option D is wrong because setting auto-negotiation does not guarantee link stability if the SFP is faulty.

8
Multi-Selectmedium

Which THREE of the following are required for a successful FCoE deployment on a Cisco MDS switch?

Select 3 answers
A.Enable the FCoE feature globally
B.Configure DCB with Priority Flow Control on the FCoE VLAN interfaces
C.Enable FIP snooping on the FCoE VLAN
D.Set the MTU to 9216 bytes on all FCoE interfaces
E.Create a VSAN and map to the FCoE VLAN
AnswersA, B, E

Required to run FCoE.

Why this answer

FCoE requires: enable FCoE feature, configure a VSAN for FCoE, and ensure DCB with PFC is configured. FIP snooping is optional but not required for basic operation. Jumbo frames are necessary but not a switch config step.

Options A, B, and D are correct. Options C and E are not mandatory.

9
Multi-Selecteasy

Which TWO statements about NPV configuration on a Cisco MDS switch are true? (Choose two.)

Select 2 answers
A.The core switch must have NPV enabled as well.
B.NPV mode is enabled globally with the 'npv enable' command.
C.All downstream interfaces must be F ports.
D.Interfaces connecting to the core switch must be configured as NP ports.
E.NPV mode is configured per VSAN.
AnswersB, D

Yes, 'npv enable' in global config.

Why this answer

Options A and B are correct. Others are incorrect.

10
MCQeasy

Which feature allows a single Fibre Channel port to log in with multiple N-port IDs, enabling a host to connect to multiple targets through one port?

A.FCoE
B.VSAN
C.NPIV
D.NPV
AnswerC

NPIV enables multiple N-port IDs per physical port.

Why this answer

NPIV (N_Port ID Virtualization) allows a single physical FC port to have multiple N_Port IDs, each with its own WWPN. This is used for virtualization. Option A is wrong because NPV is for switch-to-switch.

Option B is wrong because VSANs are for segmentation. Option D is wrong because FCoE is a different protocol.

11
MCQhard

A storage team is implementing zoning in a Fibre Channel fabric. They want a method where zone members are identified by their World Wide Port Name (WWPN) and the fabric enforces access based on that, without relying on switch port information. Which type is this?

A.Soft zoning using domain/port
B.Hard zoning using WWPN
C.Hard zoning using port WWN
D.Soft zoning using WWPN
AnswerD

Soft zoning filters by WWPN via name server.

Why this answer

Option A is correct: Soft zoning uses WWPN to define members and is enforced by the name server, not by the switch port. Hard zoning uses domain/port pairs. Option B is wrong because hard zoning uses port WWN is incorrect.

Option C is wrong: Hard zoning uses domain/port. Option D is wrong: Hard zoning does not use WWPN.

12
MCQeasy

A small business SAN consists of a single Cisco MDS 9148S switch with 16 Gb Fibre Channel ports. The storage array has four active paths to the switch, and four servers each have two HBAs. The administrator wants to ensure that all paths are utilized and that no single point of failure exists. Currently, all devices are in a single VSAN and zoning is permissive (default deny). After powering on all devices, the administrator notices that the storage array only logs in on two of its four ports. The other two ports show 'no light'. The switch has not been configured with any port settings. What is the most likely cause?

A.The switch ports need to have their speed manually configured to match the array.
B.The unused ports are in a different VSAN.
C.The zoning configuration prevents the array from logging in on those ports.
D.The storage array's other two ports are not physically connected or are disabled on the array end.
AnswerD

No light indicates the link is down; likely the cables are missing or ports disabled.

Why this answer

Default switch configuration does not disable ports; likely the other two ports on the storage array are not cabled or are administratively down. Option A is correct. Option B is wrong because port speed auto-negotiation usually works.

Option C is wrong because VSAN cannot disable ports. Option D is wrong because zoning does not affect link state.

13
MCQhard

In a Cisco UCS environment, which component provides the Fibre Channel connectivity to the SAN switches when using FCoE?

A.IOM (I/O Module)
B.Cisco VIC adapter
C.UCS Manager
D.UCS Fabric Interconnect
AnswerD

FI provides FCoE uplinks.

Why this answer

In a Cisco UCS environment, the Fabric Interconnect (FI) is the component that provides Fibre Channel connectivity to SAN switches when using FCoE. The FI integrates both Ethernet and Fibre Channel traffic, performing FCoE encapsulation and forwarding the Fibre Channel frames to the SAN via its native Fibre Channel uplink ports. This allows the UCS domain to connect directly to Fibre Channel SAN fabrics without requiring external FCoE-capable switches.

Exam trap

Cisco often tests the misconception that the IOM or VIC adapter directly provides Fibre Channel connectivity, when in fact the Fabric Interconnect is the central aggregation and conversion point for FCoE-to-FC traffic in a UCS domain.

How to eliminate wrong answers

Option A is wrong because the IOM (I/O Module) is a passive midplane or fabric extender that only aggregates traffic from the chassis to the Fabric Interconnects; it does not perform FCoE termination or provide native Fibre Channel uplinks to SAN switches. Option B is wrong because the Cisco VIC adapter is a server-side adapter that handles FCoE initialization and encapsulation at the host level, but it does not provide the final Fibre Channel connectivity to the SAN; that connectivity is provided upstream by the Fabric Interconnect. Option C is wrong because UCS Manager is the management plane software that configures and monitors the UCS domain, not a data-plane component that handles Fibre Channel connectivity.

14
MCQeasy

What is the purpose of NPIV (N_Port ID Virtualization) in a Fibre Channel SAN?

A.Provide encryption on Fibre Channel links.
B.Allow a single physical port to register multiple N_port IDs.
C.Enable multiple paths between initiator and target.
D.Allow a switch to act as an NPV device.
AnswerB

Enables virtualization.

Why this answer

NPIV allows a single physical Fibre Channel N_Port to register multiple unique N_Port IDs (FCIDs) with the fabric. This is essential for virtualizing Fibre Channel connectivity, enabling multiple virtual machines or logical partitions to share one physical HBA port while each appearing as a distinct initiator to the SAN.

Exam trap

Cisco often tests NPIV by confusing it with NPV (N_Port Virtualization) — the trap is that candidates mix up the port-level virtualization (NPIV) with the switch-level proxy mode (NPV), or assume NPIV is about multipathing or security.

How to eliminate wrong answers

Option A is wrong because encryption on Fibre Channel links is provided by FC-SP (Fibre Channel Security Protocol) or hardware-level encryption, not by NPIV. Option C is wrong because enabling multiple paths between initiator and target is the function of multipathing software (e.g., EMC PowerPath, native MPIO), not NPIV. Option D is wrong because a switch acting as an NPV device is the definition of N_Port Virtualization (NPV), which is a different technology that uses NPIV to proxy multiple N_Port IDs upstream, but the switch itself is not an NPV device; NPV is a mode for edge switches to reduce FCIDs.

15
Multi-Selectmedium

A team is configuring FCoE on a Cisco Nexus switch. Which TWO steps are mandatory to establish a lossless FCoE link?

Select 2 answers
A.Enable FCoE on the interface using the 'fcoe' command
B.Enable Priority Flow Control (PFC) as a separate CLI
C.Create a VSAN and map it to an FCoE VLAN
D.Configure DCBX to advertise and negotiate FCoE capabilities
E.Set the MTU to 9216 bytes to accommodate FCoE frames
AnswersA, D

FCoE must be enabled per interface.

Why this answer

Options A and C are correct. FCoE must be explicitly enabled on the interface. DCBX must be configured (or enabled) to negotiate PFC and other parameters for lossless operation.

Option B is incorrect: VSAN creation is part of FCoE configuration, but not mandatory on the interface level (VSANs are created globally). Option D is incorrect: MTU must be set to 2500 bytes (jumbo) for FCoE, not 9216. Option E is incorrect: PFC is enabled via DCBX, not as a separate command on the interface.

16
Multi-Selectmedium

Which TWO conditions require the use of NPIV in a Fibre Channel SAN? (Choose two.)

Select 2 answers
A.Connecting a tape library that uses multiple LUNs to a single host.
B.Connecting an NPV switch to an upstream switch.
C.Enabling FCoE transit over a lossless Ethernet network.
D.Connecting two switches over an ISL.
E.Virtualizing a server with multiple virtual machines each needing a separate WWPN.
AnswersA, E

NPIV can present multiple identities for LUN masking.

Why this answer

Option A is correct because NPIV (N_Port ID Virtualization) allows a single physical Fibre Channel N_Port to register multiple unique WWPNs (World Wide Port Names), enabling a tape library with multiple LUNs to present each LUN as a separate target to the host. Without NPIV, the host would see only one WWPN for the tape library, limiting LUN access and management flexibility.

Exam trap

The trap here is that candidates confuse NPIV with NPV (N_Port Virtualization) or assume NPIV is required for any multi-LUN device, but NPIV is specifically for virtualizing N_Port identities, not for general multi-LUN access or switch-to-switch links.

17
MCQmedium

A storage administrator reports that an FC initiator cannot log in to the SAN. The FC switch shows the following on the interface connected to the initiator: 'VSAN 100, State: Offline'. Which action should be taken to resolve the issue?

A.Create a zone including the initiator and target
B.Change the interface VSAN to match the initiator
C.Increase the number of buffer credits on the interface
D.Configure port speed manually on the switch interface
AnswerD

Forcing the port speed can stop flapping and bring the link online.

Why this answer

The interface state 'Offline' in VSAN 100 indicates a Layer 1 or Layer 2 issue, often caused by a speed mismatch between the FC initiator and the switch interface. Configuring the port speed manually on the switch interface forces the link to negotiate at a specific speed, resolving the mismatch and bringing the interface online. This is a common fix when auto-negotiation fails or the initiator does not support the default speed settings.

Exam trap

Cisco often tests the distinction between link-level issues (offline state) and fabric-level issues (zoning, VSAN membership), leading candidates to incorrectly choose zoning or VSAN changes when the root cause is a physical or speed mismatch.

How to eliminate wrong answers

Option A is wrong because zoning controls which devices can communicate (security/fabric login), but the interface is offline, meaning the physical or link-level parameters are not established yet; zoning cannot fix a down interface. Option B is wrong because the interface is already in VSAN 100 (as shown in the output), so changing the VSAN would not address the offline state; the issue is at the physical or link layer, not the VSAN membership. Option C is wrong because buffer credits manage flow control and buffer-to-buffer credit starvation, but they do not cause an interface to be offline; an offline state indicates a link-level problem (e.g., speed/negotiation), not a credit exhaustion issue.

18
MCQhard

An FCoE link between a Nexus switch and a storage array fails to come up. The switch is configured as an FCF. The administrator runs 'show interface ethernet 1/1' and sees the interface is up/up. Which command will most likely reveal the root cause?

A.show vlan id 100
B.show lldp neighbors interface ethernet 1/1
C.show fcoe database
D.show spanning-tree interface ethernet 1/1
AnswerC

Correct: Shows FCoE session and VLAN status.

Why this answer

Option D is correct because FCoE initialization involves multiple steps; 'show fcoe database' shows FCoE VLAN and login status. Option A is incorrect because LLDP is used for DCBX, not FCoE state. Option B is incorrect because spanning-tree does not affect FCoE.

Option C is incorrect because VLAN status does not show FCoE negotiation.

19
MCQhard

A Cisco MDS switch has the above configuration on two 16 Gbps FC interfaces. An engineer connects an initiator to fc1/2 and a target to fc1/1. The initiator cannot discover the target. What is the most likely cause?

A.The fc1/2 interface is configured as an F-port but the initiator requires an FL-port.
B.The fc1/1 interface is configured as dedicated rate-mode but the target expects shared.
C.The fc1/2 interface is configured as shared rate-mode which prevents F-port operation.
D.The fc1/1 interface is configured as an E-port but is connected to a storage target.
AnswerD

An E-port is for inter-switch links; the target should be connected to an F-port.

Why this answer

Option D is correct because the configuration shows interface fc1/1 with the command 'switchport mode E', which explicitly configures it as an E-port (expansion port). E-ports are used to interconnect two Fibre Channel switches, not to connect a storage target. When a target is connected to an E-port, the link will not come up properly because the target expects to be connected to an F-port (fabric port) or FL-port, preventing discovery by the initiator.

Exam trap

Cisco often tests the distinction between port types (E-port vs. F-port) and their allowed connections, trapping candidates who overlook that an E-port is strictly for switch-to-switch links, not for attaching end devices like targets or initiators.

How to eliminate wrong answers

Option A is wrong because the fc1/2 interface is configured as an F-port (via 'switchport mode F'), which is the correct port type for connecting an initiator; an FL-port is only needed if the initiator is an NL_Port (loop device), and there is no indication of an arbitrated loop. Option B is wrong because rate-mode (dedicated or shared) affects bandwidth allocation, not port type or device discovery; a target can operate with either rate-mode setting. Option C is wrong because shared rate-mode does not prevent F-port operation; F-ports can operate in shared rate-mode, and the initiator's failure to discover the target is unrelated to rate-mode.

20
Multi-Selecthard

Which TWO of the following are valid methods to recover from buffer credit loss on a Fibre Channel link?

Select 2 answers
A.Reduce the link speed.
B.Increase the BB_Credit value.
C.Enable WRED on the switch.
D.Use port channel to aggregate links.
E.Credit recovery using RDMA.
AnswersA, B

Lower speed reduces the number of credits needed to maintain the link.

Why this answer

Reducing the link speed is a valid method to recover from buffer credit loss because it decreases the number of frames transmitted per unit time, allowing the receiver's buffer credits to replenish and preventing further overrun. This is a temporary workaround that reduces the effective bandwidth but can stabilize the link when buffer credit starvation occurs due to distance or congestion.

Exam trap

Cisco often tests the misconception that increasing link speed or aggregating links (port channels) can solve buffer credit issues, but the correct approach is to either reduce speed or increase BB_Credits, as credit loss is a flow-control problem, not a bandwidth problem.

21
MCQmedium

A storage administrator needs to configure zoning while minimizing administrative overhead and allowing multiple initiators to access multiple targets without having to change zones when new members are added. Which zoning approach is best?

A.Zoning by naming using a zone alias for initiators and another for targets
B.Multiple initiator-multiple target zoning (all devices in one zone)
C.Single initiator-single target zoning
D.Single initiator-multiple target zoning (initiator-based)
AnswerA

Using zone aliases groups initiators and targets; adding new members to the alias automatically includes them in the zone, reducing overhead.

Why this answer

Option A is correct because zoning by name using zone aliases decouples the zone configuration from the physical port or WWN, allowing administrators to group initiators and targets into separate aliases. When new members are added to an alias, the zone automatically includes them without manual zone reconfiguration, minimizing administrative overhead while supporting multiple initiators and multiple targets.

Exam trap

Cisco often tests the distinction between zoning by WWN (hard zoning) versus zoning by alias (soft zoning), and the trap here is that candidates mistakenly choose 'multiple initiator-multiple target zoning' (Option B) thinking it is the simplest, but they overlook that it eliminates all isolation and violates Fibre Channel security best practices, whereas alias-based zoning provides both scalability and proper segmentation.

How to eliminate wrong answers

Option B is wrong because placing all devices in a single zone violates Fibre Channel best practices by creating a flat, non-segmented fabric that increases the risk of RSCN storms and reduces security, and it does not minimize overhead when adding members (the zone still exists but offers no isolation). Option C is wrong because single initiator-single target zoning creates a one-to-one mapping, which requires creating and managing many zones for multiple initiators and targets, increasing administrative overhead and not allowing multiple initiators to access multiple targets without zone changes. Option D is wrong because single initiator-multiple target zoning (initiator-based) requires a separate zone for each initiator, so adding a new initiator still requires creating a new zone, and it does not allow multiple initiators to access the same targets without additional zone modifications.

22
MCQmedium

A data center engineer is designing a Fibre Channel SAN for high availability. The design includes two MDS 9710 directors connected to multiple storage arrays. Which best practice should be followed when configuring NPV mode on the switches connecting the hosts?

A.Enable VSAN interop on the NPV switch to support multiple storage arrays
B.Connect each NPV switch to a single core switch for simplicity
C.Use FC trunking between NPV and core switches to increase bandwidth
D.Dual-home each NPV switch to two separate core switches for redundancy
AnswerD

Dual-homing ensures high availability.

Why this answer

Option D is correct because dual-homing each NPV switch to two separate core switches ensures that if one core switch fails, the NPV switch can still forward traffic through the other core switch. In NPV mode, the switch acts as a passthrough, and connecting to two separate core directors provides path redundancy without requiring the NPV switch to perform full Fibre Channel routing. This design aligns with high-availability best practices for Fibre Channel SANs.

Exam trap

Cisco often tests the misconception that FC trunking alone provides redundancy, but trunking only increases bandwidth and link aggregation, not failover independence; dual-homing to separate core switches is required for true high availability.

How to eliminate wrong answers

Option A is wrong because VSAN interop is not a feature of NPV mode; NPV switches inherit the VSAN configuration from the core switch and do not need interop enabled to support multiple storage arrays. Option B is wrong because connecting each NPV switch to a single core switch creates a single point of failure, violating high-availability design principles. Option C is wrong because FC trunking is used to aggregate multiple physical links into a single logical link for bandwidth, but it does not provide the necessary redundancy; dual-homing is the correct method for redundancy.

23
MCQeasy

Which statement about Fibre Channel buffer credits is true?

A.They are used for load balancing across multiple paths.
B.They control the flow of frames between directly connected ports.
C.They are allocated per VSAN.
D.They detect CRC errors in frames.
AnswerB

Buffer credits manage the number of outstanding frames.

Why this answer

Fibre Channel buffer credits implement a credit-based flow control mechanism between directly connected ports (Nx_Port to Fx_Port or E_Port to E_Port). Each port advertises its available buffer credits (BB_Credit) to the directly attached peer, and the sender can only transmit a frame when it has a positive credit count. This prevents frame loss due to buffer overflow at the receiver, ensuring lossless transmission over the link.

Exam trap

Cisco often tests the distinction between flow control (buffer credits) and error detection (CRC) or fabric-level features (VSANs, load balancing), so the trap here is confusing a link-level mechanism with higher-layer or fabric-wide functions.

How to eliminate wrong answers

Option A is wrong because load balancing across multiple paths is handled by multipathing software (e.g., EMC PowerPath, native OS MPIO) or Fibre Channel fabric-level routing (e.g., FSPF), not by buffer credits. Option C is wrong because buffer credits are allocated per physical port or per virtual interface (e.g., NPIV), not per VSAN; VSANs are logical fabric partitions that do not directly affect port-level buffer credit allocation. Option D is wrong because CRC error detection is performed by the Fibre Channel frame header and CRC field, verified by the receiving port hardware; buffer credits are a flow control mechanism, not an error detection mechanism.

24
MCQmedium

In a Fibre Channel SAN, flow control is managed by buffer credits. Which statement about buffer credits is accurate?

A.Buffer credits are allocated per VSAN to isolate traffic
B.Increasing buffer credits always improves I/O performance
C.Buffer credits are used in FCoE to ensure lossless delivery
D.Buffer credits help manage congestion and ensure lossless delivery over distance
AnswerD

BB_credits allow a sender to send multiple frames without waiting for acknowledgment.

Why this answer

Buffer credits are a flow control mechanism in Fibre Channel that manage congestion by tracking the number of frames a sender can transmit before receiving an acknowledgment. They ensure lossless delivery over distance by preventing buffer overflow at the receiver, which is critical for maintaining data integrity in SANs. Option D correctly states this dual role of congestion management and lossless delivery.

Exam trap

Cisco often tests the distinction between Fibre Channel buffer credits and FCoE's Priority Flow Control (PFC), so the trap here is confusing the two lossless mechanisms and assuming buffer credits apply to FCoE.

How to eliminate wrong answers

Option A is wrong because buffer credits are allocated per port, not per VSAN; VSANs isolate traffic at the fabric level, but buffer credits operate at the physical link level to manage frame flow. Option B is wrong because increasing buffer credits does not always improve I/O performance; it can help over long distances but may waste memory if set too high for short links, and performance gains depend on other factors like link speed and application workload. Option C is wrong because FCoE uses a different lossless mechanism based on IEEE 802.1Qbb Priority Flow Control (PFC), not Fibre Channel buffer credits; buffer credits are native to Fibre Channel, not FCoE.

25
MCQhard

A company is deploying a new SAN with two MDS 9148S switches in a single VSAN. They want to ensure that a failure of one switch does not affect storage traffic. Which technology should be implemented?

A.Implement FCoE to Ethernet storage.
B.Enable NPIV on all ports.
C.Configure a port channel between the switches.
D.Create a redundant fabric by connecting both switches to each storage array and host via multiple paths.
AnswerD

This provides path redundancy; if one switch fails, the other continues.

Why this answer

For redundancy in a single VSAN, using Inter-Switch Links (ISLs) between the two switches and enabling NPV on the edge switches (or simply having the switches in a fabric) is typical. However, the question implies two switches. For high availability, they should connect both switches with multiple ISLs and use VSAN-based trunking.

Option A is wrong because port channels are for link aggregation, not switch failure. Option B is wrong because FCoE is not relevant. Option D is wrong because NPIV is for port virtualization.

26
MCQmedium

A company is deploying FCoE in their data center. The design includes a Cisco Nexus 9000 switch with FEX modules. The storage team insists on using dedicated FCoE VLANs. Which best practice should be followed to ensure lossless behavior for FCoE traffic?

A.Configure traffic shaping on FCoE interfaces
B.Use the same VLAN for FCoE and IP traffic to reduce VLAN count
C.Disable flow control on all interfaces
D.Enable PFC on the switch for the FCoE VLAN
AnswerD

PFC provides lossless behavior for the CoS used by FCoE.

Why this answer

Option D is correct because FCoE requires lossless transport to prevent frame drops that could corrupt Fibre Channel frames. Priority Flow Control (PFC), defined in IEEE 802.1Qbb, enables pause frames on a per-priority basis, allowing the FCoE VLAN to be configured with a dedicated priority class that receives no-drop treatment. On Cisco Nexus 9000 switches, this is achieved by enabling PFC on the specific VLAN used for FCoE traffic, ensuring lossless behavior without affecting other traffic classes.

Exam trap

Cisco often tests the misconception that flow control (IEEE 802.3x) is sufficient for FCoE, but the trap here is that standard link-level flow control pauses all traffic on the link, whereas PFC provides granular per-priority lossless handling required for FCoE.

How to eliminate wrong answers

Option A is wrong because traffic shaping is a rate-limiting mechanism that smooths bursts but does not guarantee lossless delivery; FCoE relies on PFC for per-priority pause, not shaping. Option B is wrong because using the same VLAN for FCoE and IP traffic would mix lossless and lossy traffic, causing congestion and frame drops for FCoE; dedicated FCoE VLANs are a best practice to isolate lossless traffic. Option C is wrong because disabling flow control entirely removes the ability to pause traffic, which would cause FCoE frames to be dropped under congestion, violating the lossless requirement.

27
Multi-Selectmedium

An engineer is designing a SAN for a virtualized environment. Which two best practices should be followed for Fibre Channel zoning?

Select 2 answers
A.Use single-initiator zoning.
B.Use multiple initiators in a single zone.
C.Use soft zoning exclusively.
D.Disable zoning for performance.
E.Zone by WWPN rather than WWNN.
AnswersA, E

Simplifies troubleshooting and security.

Why this answer

Single-initiator zoning (also known as one-to-one zoning) is a best practice because it restricts each Fibre Channel zone to exactly one initiator (host HBA) and one or more target ports. This eliminates the risk of RSCN storms propagating across multiple initiators, reduces fabric instability, and simplifies troubleshooting by ensuring clear, predictable paths between each host and its storage.

Exam trap

Cisco often tests the misconception that soft zoning is sufficient for security, but the trap here is that soft zoning only filters name server queries and does not prevent a device from directly addressing another device's port if it knows the Fibre Channel address.

28
Multi-Selectmedium

An engineer is configuring a storage network with FCoE and must ensure that the FCoE traffic does not interfere with standard LAN traffic. Which two mechanisms should be implemented?

Select 2 answers
A.Use the same VLAN for FCoE and LAN.
B.Disable flow control on FCoE VLAN.
C.Enable PFC on the FCoE VLAN.
D.Assign FCoE traffic to a dedicated VLAN.
E.Use jumbo frames for LAN traffic only.
AnswersC, D

Provides lossless Ethernet.

Why this answer

Option C is correct because FCoE requires lossless transport to prevent frame drops that would corrupt Fibre Channel frames. Priority Flow Control (PFC), defined by IEEE 802.1Qbb, enables pause frames on a per-priority basis, allowing the FCoE VLAN to be configured as lossless while standard LAN traffic remains best-effort. This ensures FCoE traffic does not interfere with LAN traffic by isolating the flow control behavior.

Exam trap

The trap here is that candidates often think disabling flow control (Option B) is necessary to avoid interference, but FCoE actually requires flow control (PFC) to be enabled, and the key is to isolate it to a dedicated VLAN.

29
MCQeasy

Which of the following is a required characteristic of an FCoE SAN?

A.Jumbo frames must be enabled.
B.Spanning Tree Protocol must be disabled.
C.Link aggregation (LACP) is required.
D.Lossless Ethernet (PFC) must be enabled.
AnswerD

FCoE requires no-drop.

Why this answer

FCoE (Fibre Channel over Ethernet) requires a lossless Ethernet fabric to prevent frame drops, which would corrupt Fibre Channel frames. Priority Flow Control (PFC), defined in IEEE 802.1Qbb, enables lossless operation by pausing traffic on individual CoS queues, ensuring no-drop behavior for FCoE traffic. Without PFC, standard Ethernet's best-effort delivery would cause frame loss, breaking FCoE's reliability requirements.

Exam trap

Cisco often tests the misconception that jumbo frames are mandatory for FCoE, but the actual required characteristic is lossless Ethernet via PFC, as jumbo frames are optional and only improve efficiency.

How to eliminate wrong answers

Option A is wrong because jumbo frames are not a required characteristic of an FCoE SAN; while they can improve efficiency by reducing per-frame overhead, FCoE can operate with standard 1500-byte MTU, and the mandatory requirement is lossless Ethernet via PFC. Option B is wrong because Spanning Tree Protocol (STP) is not required to be disabled for FCoE; in fact, FCoE can run over STP-enabled networks, though dedicated FCoE SANs often use STP-disabled designs (e.g., vPC or FabricPath) for convergence, but disabling STP is not a mandatory characteristic. Option C is wrong because link aggregation (LACP) is not required for FCoE; FCoE can operate over single links or port channels, and while LACP can provide redundancy and bandwidth, it is not a prerequisite for FCoE functionality.

30
MCQmedium

A storage network engineer notices high buffer credit starvation counters on an inter-switch link. What is the most effective solution to reduce this issue?

A.Change the ISL port mode from E to F.
B.Reduce the ISL speed to 1 Gbps.
C.Increase the number of buffer credits on the ISL.
D.Enable QoS to prioritize buffer credit recovery.
AnswerC

More buffer credits accommodate longer distances and reduce starvation.

Why this answer

Buffer credit starvation indicates insufficient credits for the distance. Option B is correct. Option A is wrong because ISL ports should be E ports, not F.

Option C is wrong because reducing speed may not help. Option D is wrong because QoS can prioritize but not increase credits.

31
MCQeasy

An engineer needs to isolate storage traffic for different departments using Fibre Channel switches. Which technology should be used?

A.Zoning
B.Trunking
C.NPV (N-Port Virtualization)
D.VSAN (Virtual SAN)
AnswerD

Correct: VSANs create separate Fibre Channel fabrics for isolation.

Why this answer

VSAN (Virtual SAN) is the correct technology because it allows the engineer to create multiple isolated virtual SANs on a single physical Fibre Channel fabric. Each VSAN operates as an independent SAN with its own fabric services, security policies, and traffic isolation, enabling different departments to have dedicated storage traffic without interference.

Exam trap

Cisco often tests the distinction between zoning and VSANs, where candidates mistakenly believe that zoning alone provides full traffic isolation, but zoning only controls device communication within a single VSAN and does not isolate fabric services or management domains.

How to eliminate wrong answers

Option A is wrong because zoning only controls which devices can communicate within a single VSAN, but does not provide the complete isolation of fabric services and traffic that is required for separate departments. Option B is wrong because trunking in Fibre Channel refers to carrying multiple VSANs over a single ISL (Inter-Switch Link), not to isolating storage traffic for different departments. Option C is wrong because NPV (N-Port Virtualization) is used to aggregate multiple N-Ports into a single physical link to reduce domain IDs in a fabric, not to isolate traffic between departments.

32
MCQeasy

An administrator wants to ensure that a specific initiator can only access a single target LUN. Which zoning approach satisfies this requirement?

A.Use LUN zoning to map the initiator to a specific LUN ID.
B.Implement soft zoning based on domain IDs.
C.Configure a zone with the initiator WWPN and the target WWPN.
D.Place the initiator and target in different VSANs.
AnswerA

LUN zoning restricts access to a specific LUN on the target.

Why this answer

LUN zoning restricts access to specific LUNs. Option C is correct. Option A is wrong because WWPN zoning allows access to all LUNs on the target.

Option B is wrong because VSANs separate traffic but don't restrict LUNs. Option D is wrong because soft zoning is not enforced.

33
MCQhard

During a SAN performance analysis, a Fibre Channel link shows a high number of CRC errors. The link operates at 16 Gbps over a 10 km dark fiber. Which corrective action is least likely to resolve the issue?

A.Increase the buffer-to-buffer credit count on the link.
B.Replace the fiber cable with a single-mode fiber cable if multimode is used.
C.Clean all fiber connectors and inspect for damage.
D.Verify that the SFP+ optics match the fiber type and distance.
AnswerA

Buffer credits affect flow control, not physical errors.

Why this answer

CRC errors are often due to signal integrity. Option D is least likely because increasing credits does not fix physical layer issues. Option A corrects possible mismatch.

Option B can reduce attenuation. Option C proper cleaning.

34
MCQeasy

An engineer needs to connect a new server to an existing FC SAN. The server is located 50 km away from the data center. Which technology should be used to extend the FC SAN over this distance?

A.iSCSI
B.FCIP
C.FCoE
D.Direct FC connection with 10km optics
AnswerB

FCIP is designed to extend FC over long distances using IP networks.

Why this answer

FCIP (Fibre Channel over IP) is the correct choice because it encapsulates Fibre Channel frames inside TCP/IP packets, enabling the extension of FC SANs over long distances (beyond the 10 km limit of standard optics) by leveraging existing IP WAN infrastructure. This allows the 50 km connection while preserving native Fibre Channel semantics and fabric services.

Exam trap

Cisco often tests the distinction between FC extension protocols (FCIP) and alternative storage protocols (iSCSI, FCoE), trapping candidates who confuse 'extending FC' with 'replacing FC' or who assume long-reach optics can overcome distance limits without protocol adaptation.

How to eliminate wrong answers

Option A (iSCSI) is wrong because it is a storage networking protocol that carries SCSI commands over IP networks, not Fibre Channel frames, so it cannot extend an existing FC SAN; it would require native iSCSI initiators and targets. Option C (FCoE) is wrong because it maps Fibre Channel over Ethernet but is limited to data center bridging (DCB) environments with a maximum reach of typically 10 km over dark fiber, not 50 km. Option D (Direct FC connection with 10km optics) is wrong because standard Fibre Channel optics (e.g., 10 km SFP+) cannot achieve a 50 km link; even long-reach optics (e.g., 40 km) are impractical without repeaters, and FC is not designed for such distances without protocol extension.

35
MCQmedium

An MDS switch is configured with VSANs 100 and 200. The engineer wants to isolate traffic between two storage arrays on the same physical fabric. Which best practice should be applied?

A.Use zones within the same VSAN to separate arrays.
B.Place each array in a different VSAN.
C.Enable QoS to prioritize storage traffic.
D.Configure a port channel between the switches.
AnswerB

VSANs provide complete isolation.

Why this answer

Option B is correct because VSANs provide complete isolation of traffic at Layer 2, creating separate fabric topologies within the same physical infrastructure. Placing each storage array in a different VSAN ensures that Fibre Channel frames from one array never reach the other, even though they share the same MDS switch hardware. This is the recommended best practice for separating storage traffic that must not interact.

Exam trap

The trap here is that candidates confuse zoning with VSAN isolation, thinking that zones within a single VSAN provide the same level of separation, when in fact zones only restrict end-device communication while leaving fabric services and control traffic shared across the entire VSAN.

How to eliminate wrong answers

Option A is wrong because zones within the same VSAN only control which initiators can talk to which targets; they do not isolate broadcast traffic, fabric services, or control-plane frames, so the arrays would still share the same VSAN domain and could be affected by each other's events. Option C is wrong because QoS prioritizes traffic but does not provide isolation; it only manages bandwidth and latency, not security or Layer 2 separation. Option D is wrong because a port channel aggregates bandwidth and provides link-level redundancy between switches; it does not separate traffic between storage arrays on the same physical fabric.

36
MCQeasy

Which of the following is a benefit of using Fibre Channel over Ethernet (FCoE) in a data center?

A.It increases the maximum distance of Fibre Channel links.
B.It reduces cabling complexity by using a unified fabric.
C.It provides native Fibre Channel security.
D.It eliminates the need for zoning.
AnswerB

Convergence reduces cabling.

Why this answer

FCoE encapsulates Fibre Channel frames over Ethernet networks, allowing storage and data traffic to share the same physical infrastructure. This consolidation reduces cabling complexity and the number of required switches, adapters, and power/cooling overhead, which is the core benefit of a unified fabric.

Exam trap

Cisco often tests the misconception that FCoE eliminates Fibre Channel management features like zoning or security, when in fact it preserves them while only consolidating the physical transport layer.

How to eliminate wrong answers

Option A is wrong because FCoE does not increase the maximum distance of Fibre Channel links; native Fibre Channel can already reach up to 10 km (standard) or more with repeaters, while FCoE is typically limited to the same data center or campus Ethernet distance constraints (100 m for copper, up to 10 km with fiber). Option C is wrong because FCoE does not provide native Fibre Channel security; it inherits Ethernet security mechanisms (e.g., ACLs, 802.1AE MACsec) but does not include FC-SP (Fibre Channel Security Protocol) natively. Option D is wrong because FCoE still requires zoning (via ENode or FCoE-specific constructs like FCoE VLANs and FCoE Initialization Protocol) to control which initiators can access which targets, just as in native Fibre Channel.

37
MCQeasy

A Cisco MDS switch is connected to a Fibre Channel storage array and a host. The host cannot see the storage LUNs. The 'show flogi database' command on the MDS shows the host's WWPN, but the 'show fcns database' does not show the storage target. What is the most likely cause?

A.The zone configuration is incorrect.
B.The host and target are in different VSANs.
C.The storage target is not logged into the fabric.
D.The host is not in the name server database.
AnswerC

The 'show fcns database' shows only devices that have logged into the fabric; if the target is not logged in, it won't appear.

Why this answer

The 'show flogi database' command displays all devices that have completed the Fabric Login (FLOGI) process, which the host has done. However, the 'show fcns database' command lists only devices that have registered with the Fabric Name Server (via FDISC or FLOGI with PLOGI). Since the storage target is not in the name server database, it means the target has not logged into the fabric (or has not registered its FC-4 type/SCSI features), preventing the host from discovering its LUNs.

This is the most likely cause because the host can see its own WWPN in the FLOGI database but cannot see the target in the FCNS database.

Exam trap

Cisco often tests the distinction between FLOGI (physical login) and FCNS registration (name server entry), leading candidates to incorrectly assume that a device visible in 'show flogi database' must also be in the fabric name server database.

How to eliminate wrong answers

Option A is wrong because an incorrect zone configuration would still allow the host and target to appear in the FCNS database (zoning only restricts access, not registration); the issue is that the target is not even registered. Option B is wrong because if the host and target were in different VSANs, the host's FLOGI would not appear in the same VSAN's FLOGI database as the target's VSAN, but the host's WWPN is visible, implying they are in the same VSAN. Option D is wrong because the host is already in the name server database (as shown by the FLOGI entry, which typically triggers name server registration), so the problem is the target's absence, not the host's.

38
Multi-Selectmedium

Which TWO of the following are best practices when interconnecting two Cisco MDS 9700 directors via Fibre Channel ISLs?

Select 2 answers
A.Enable NPIV on the ISL ports to allow multiple FCIDs
B.Use Fibre Channel port channels to bundle multiple ISLs
C.Configure the ISL ports as trunking E_ports
D.Configure the ISL ports as F_ports to increase scalability
E.Use E_port configuration (not F_port) for inter-switch links
AnswersC, E

Trunking E_ports allow multiple VSANs on a single link.

Why this answer

Options A and C are correct. Using trunk mode allows multiple VSANs over a single ISL (E_port trunking). E_ports are the standard port type for ISLs.

Option B is incorrect because FC port channels are not used for ISLs (E_port trunking is used). Option D is incorrect: NPIV is used for host virtualization, not ISLs. Option E is incorrect: F_ports are for connecting hosts or targets.

39
MCQeasy

A Fibre Channel switch port is experiencing high latency due to insufficient buffer credits. What is the most likely cause?

A.CRC errors on the fibre optic cable
B.High oversubscription ratio on the port
C.Long-distance link between switches
D.VSAN ID mismatch between end devices
AnswerC

Correct: Long-distance links require more buffer credits to maintain throughput.

Why this answer

Option A is correct because buffer credits are used to manage the flow of frames across long-distance links. Option B is incorrect because oversubscription affects bandwidth, not buffer credits. Option C is incorrect because CRC errors indicate data corruption.

Option D is incorrect because VSAN mismatch prevents communication.

40
Multi-Selecteasy

Which TWO of the following Fibre Channel port types are used to connect end devices such as hosts or storage?

Select 2 answers
A.FL port
B.E port
C.N port
D.F port
E.NP port
AnswersC, D

N port is on the end device.

Why this answer

Port types: N port (host) and F port (switch facing host) connect end devices. E port is for ISL, NP port for NPV, and FL port for loop. Options A and D are correct.

Options B, C, and E are incorrect.

41
MCQhard

A large enterprise uses Cisco Nexus 5548UP switches in FCoE mode. The storage array is connected via native FC to an MDS 9700. The FCoE switches are connected to the MDS via FC uplinks. Recently, the storage team deployed a new FCoE initiator that requires access to a specific LUN. After configuring the zone and VSAN, the initiator cannot discover the target. The zone includes the pWWN of the target and the FCoE initiator's pWWN (derived from its MAC address). The initiator is in VSAN 100, and the target is in the same VSAN. The MDS show flogi database shows the initiator. The show fcoe database on the Nexus shows the initiator but the session is not active (state: FIP-VN_Port not logged in). The engineer checks the FIP snooping policy and notices that the FCoE VLAN to VSAN mapping is correct. What is the most likely issue?

A.The MDS does not have a route to the FCoE initiator's VSAN
B.The FCoE initiator is not using the correct VN_Port MAC address
C.The FIP snooping policy is blocking the FLOGI
D.The FCoE NPV is not enabled on the Nexus
AnswerC

FIP snooping uses ACLs to enforce zoning; if misconfigured, it can drop FLOGI frames.

Why this answer

The FCoE initiator appears in the FCoE database but is not logged in, indicating the FLOGI is being dropped. The FIP snooping policy on the Nexus switch may be blocking the FLOGI traffic because the initiator's MAC address is not in the allowed FCoE MAC list or the policy is misconfigured. Incorrect VN_Port MAC would prevent FCoE database entry, NPV is not required for FCoE native mode, and routing is not an issue within the same VSAN.

42
MCQhard

A data center uses FCoE on Nexus 9000 switches. The storage team reports inconsistent performance during peak times. Queuing drops are seen on the FCoE-enabled interfaces. Which QoS configuration change would best address the issue?

A.Enable WRED on the FCoE class
B.Increase MTU on the FCoE VLAN
C.Ensure sufficient buffer allocation for the no-drop class
D.Increase the number of pause frames on the no-drop class
AnswerC

Correct: Allocating more buffers to the no-drop class prevents drops.

Why this answer

In FCoE networks, lossless behavior is required for storage traffic, which is enforced by priority flow control (PFC) on the no-drop class. Queuing drops on FCoE-enabled interfaces indicate that the no-drop class is experiencing buffer exhaustion under congestion. Increasing buffer allocation for the no-drop class ensures that FCoE frames are not dropped, maintaining the lossless fabric required by Fibre Channel over Ethernet.

Exam trap

Cisco often tests the misconception that pause frames alone guarantee lossless delivery, but the trap is that insufficient buffer allocation for the no-drop class will still cause drops under burst conditions, regardless of pause frame configuration.

How to eliminate wrong answers

Option A is wrong because WRED (Weighted Random Early Detection) is a congestion avoidance mechanism for drop-tolerant traffic (e.g., best-effort), and enabling it on the FCoE no-drop class would cause random drops, violating the lossless requirement of FCoE. Option B is wrong because increasing MTU on the FCoE VLAN does not address queuing drops caused by buffer congestion; FCoE already uses jumbo frames (typically 2500 bytes), and MTU changes affect frame size, not buffer allocation or drop behavior. Option D is wrong because increasing the number of pause frames on the no-drop class would not solve buffer exhaustion; pause frames are used by PFC to signal backpressure, but if the buffer is already full, additional pause frames cannot prevent drops—proper buffer sizing is needed to absorb bursts.

43
MCQeasy

An engineer notices that a Fibre Channel link between two Cisco MDS 9000 series switches is flapping every few minutes. The interface counters show a high number of CRC errors. What is the most likely cause of this issue?

A.NPV mode enabled on the switch
B.Incorrect zoning configuration
C.Faulty SFP or optical cable
D.VSAN mismatch between switches
AnswerC

CRC errors point to physical layer problems.

Why this answer

CRC errors on a Fibre Channel link indicate physical-layer corruption of frames, typically caused by faulty optics, dirty or damaged fiber cables, or marginal signal integrity. Flapping occurs because the link repeatedly fails to maintain proper synchronization due to excessive bit errors, triggering port reset or re-initialization. A faulty SFP or optical cable directly introduces noise or attenuation that corrupts the data stream, leading to CRC errors and link instability.

Exam trap

Cisco often tests the distinction between physical-layer issues (CRC errors, flapping) and logical/configuration issues (VSAN mismatch, zoning, NPV), tempting candidates to select a configuration-based answer when the symptoms clearly point to a hardware fault.

How to eliminate wrong answers

Option A is wrong because NPV (N_Port Virtualization) mode is a switch feature that allows a switch to act as a proxy for end devices, reducing domain IDs; it does not cause physical-layer CRC errors or link flapping. Option B is wrong because incorrect zoning configuration affects which devices can communicate (access control) but does not introduce bit errors or physical-layer corruption on the link. Option D is wrong because a VSAN mismatch between switches prevents the link from coming up at all (the port will be isolated or disabled), not cause intermittent flapping with CRC errors.

44
MCQhard

A company has two data centers connected via a WAN link using an FCIP tunnel between two Cisco MDS 9700 switches. The FCIP link is configured on a GigabitEthernet port with an MTU of 1500 bytes and uses IPSec for encryption. Recently, storage replication traffic has become slow, and the administrator notices high TCP retransmissions on the FCIP interface. The administrator checks the bandwidth utilization and sees it is only 50% of the link capacity. The storage arrays report no errors or performance issues on their local switches. The administrator also verifies that the FCIP profile is configured correctly and that compression is enabled but not causing any errors. What is the most likely cause of the TCP retransmissions?

A.The WAN link has packet loss due to a duplex mismatch.
B.IPSec encryption introduces too much overhead.
C.The FCIP profile is configured with compression that is causing delays.
D.The TCP window size is too small for the latency.
AnswerA

Duplex mismatch causes errors and retransmissions, even at moderate utilization.

Why this answer

High TCP retransmissions indicate packet loss. A duplex mismatch between the MDS switch and the WAN router can cause packet loss, even if bandwidth utilization is moderate. Option D is correct.

Option A would cause low throughput without retransmissions. Option B adds overhead but typically does not cause retransmissions. Option C (compression) can add delay but not packet loss.

45
Drag & Dropmedium

Sequence the steps to configure a Cisco UCS Fabric Interconnect (FI) for the first time.

Drag steps to the numbered slots on the right, or tap a step then tap a slot.

Steps
Order

Why this order

Initial FI setup involves IP assignment, cluster mode, user creation, uplink config, and verification.

46
MCQhard

In a multipath Fibre Channel SAN, which component is responsible for selecting the active path for I/O operations?

A.The storage target
B.The Fibre Channel switch
C.The fabric name server
D.The initiator (host HBA and multipath driver)
AnswerD

Multipath software on the host decides which path to use.

Why this answer

In a multipath Fibre Channel SAN, the initiator (host HBA and multipath driver) is responsible for selecting the active path for I/O operations. The multipath driver, such as Cisco MDS N-Port Virtualization or native OS multipathing (e.g., Linux DM-Multipath), uses path selection policies (e.g., round-robin, least-queued, or active/passive) to choose the path for each I/O request. The storage target, switch, and fabric name server do not make per-I/O path decisions; they only provide connectivity or discovery services.

Exam trap

Cisco often tests the misconception that the Fibre Channel switch or storage array controls path selection, but in reality, the initiator's multipath driver is the sole decision-maker for active I/O paths.

How to eliminate wrong answers

Option A is wrong because the storage target (LUN or array controller) presents logical units but does not select the active path for I/O; it responds to commands sent by the initiator. Option B is wrong because the Fibre Channel switch forwards frames based on destination addresses and does not perform per-I/O path selection; it is unaware of multipath policies. Option C is wrong because the fabric name server provides device discovery and address resolution (e.g., FCNS queries) but does not participate in I/O path selection.

47
MCQhard

An engineer is troubleshooting a SAN that uses FCoE. The FCoE Initialization Protocol (FIP) discovery phase is failing for one server. The server is connected to a Cisco Nexus switch configured for FCoE. Which command should be checked first?

A.show vlan fcoe
B.show npv status
C.show dcbx parameters
D.show priority-flow-control
AnswerA

This command shows FCoE VLANs and VSAN mappings, which are critical for FIP.

Why this answer

FIP discovery requires VLAN and VSAN mapping. Option A is correct. Option B is wrong because DCBX is for link-level.

Option C is wrong because NPV is for FC. Option D is wrong because priority flow control is separate.

48
Multi-Selecteasy

Which TWO of the following are valid methods to configure zoning in a Cisco MDS 9000 series switch?

Select 2 answers
A.IP address zoning
B.MAC address zoning
C.Domain/port (DID) zoning
D.Interface (fc-port) zoning
E.pWWN zoning
AnswersC, E

Uses FC domain ID and port number, another standard method.

Why this answer

Valid zoning methods are pWWN (World Wide Name) and domain/port (DID) zoning. Interface zoning is not standard; IP and MAC addresses are not used in FC zoning.

49
MCQhard

A Cisco MDS switch is configured as an NPV switch to connect to a core switch. Which statement about NPV operation is true?

A.The NPV switch allocates FC IDs to end devices from its own pool.
B.The NPV switch uses FDISC to register multiple N-Port IDs from a single physical link.
C.The NPV switch requires at least one VSAN to be defined as a fabric VSAN.
D.The NPV switch performs fabric login (FLOGI) on behalf of all attached end devices.
AnswerB

NPV uses FDISC to multiplex multiple N-Port IDs over the NP uplink to the core.

Why this answer

In N_Port Virtualization (NPV) mode, a Cisco MDS switch acts as a passthrough device that aggregates multiple end-device N_Ports onto a single uplink to a core Fibre Channel switch. The NPV switch uses the Fabric Discovery (FDISC) protocol to register multiple N_Port IDs (NPIV) from a single physical link, allowing each end device to obtain its own FC ID from the core switch. This is correct because NPV does not assign FC IDs itself but relies on the core switch for fabric login and address assignment.

Exam trap

Cisco often tests the misconception that an NPV switch performs fabric login or assigns FC IDs locally, when in fact it only forwards FLOGI/FDISC requests to the core switch and never allocates addresses itself.

How to eliminate wrong answers

Option A is wrong because an NPV switch does not allocate FC IDs from its own pool; it forwards FLOGI/FDISC requests to the core switch, which assigns FC IDs from the fabric's address space. Option C is wrong because NPV does not require any VSAN to be defined as a fabric VSAN; NPV switches operate in a passthrough mode and do not participate in fabric services like VSAN-based zoning or name server. Option D is wrong because the NPV switch does not perform FLOGI on behalf of end devices; each end device performs its own FLOGI (or FDISC for NPIV) to the core switch, and the NPV switch merely forwards these requests.

50
MCQeasy

Refer to the exhibit. The interface fc1/1 is configured as an E_port. The connected switch also has an E_port configured. However, the interface shows an 'init' state. What is the most likely cause?

A.The domain ID is not configured on either switch.
B.The speed on the remote switch interface is set to 8000 Mbps.
C.The port VSAN on the local interface is different from the remote.
D.The remote switch interface is not configured as a trunk.
AnswerB

E_ports require matching speed settings to establish a link.

Why this answer

The 'init' state on an E_port indicates that the link is up but the port is still initializing the Exchange Link Parameters (ELP) and Exchange Switch Capabilities (ESC) protocols. If the remote switch interface speed is set to 8000 Mbps (8 Gbps) while the local interface is configured for a different speed (e.g., 4 Gbps or 16 Gbps), the speed negotiation will fail, preventing the E_port from transitioning to the 'online' state. Cisco MDS switches require matching speed settings on both ends of an E_port for successful initialization.

Exam trap

Cisco often tests the distinction between 'init' and 'isolated' states, where candidates mistakenly attribute VSAN mismatch or domain ID issues to 'init', but the correct cause is often a speed mismatch or incompatible port parameters during ELP negotiation.

How to eliminate wrong answers

Option A is wrong because the domain ID is assigned dynamically via the principal switch selection process during fabric formation; an unconfigured domain ID does not prevent E_port initialization but may cause a domain ID conflict later. Option C is wrong because a mismatched port VSAN between local and remote interfaces would cause the port to enter an 'isolated' state, not 'init', as VSAN mismatch is detected after ELP exchange. Option D is wrong because E_ports are inherently trunk ports in Fibre Channel; the concept of a 'trunk' in this context refers to VSAN trunking, which is optional and not required for basic E_port operation.

51
MCQmedium

Refer to the exhibit. A new host is connected to interface fc1/3. It is not appearing in the flogi database. The switch is in NPV mode. What is the most likely reason?

A.The FCID is already allocated.
B.The host's WWPN is already in use by another device.
C.The interface is configured as an NP port.
D.The interface is in a different VSAN than the host's FLOGI.
E.The host's HBA is not compatible with NPV.
AnswerC

An NP port expects connection to a core switch, not a host; thus hosts cannot log in through it.

Why this answer

In NPV mode, a switch does not perform FLOGI processing locally; instead, it forwards FLOGI requests upstream to the core switch. For an interface to participate in NPV, it must be configured as an NP port (N_Port proxy). If interface fc1/3 is not explicitly configured as an NP port, it will not accept or forward FLOGI frames from the host, so the host never appears in the flogi database.

Exam trap

Cisco often tests the distinction between NPV mode and standard Fibre Channel switching, where candidates mistakenly assume that simply connecting a host to an NPV switch will automatically result in a FLOGI entry, ignoring the mandatory NP port configuration on the interface.

How to eliminate wrong answers

Option A is wrong because an FCID allocation conflict would generate a specific error during FLOGI, but the host is not even appearing in the flogi database, indicating the FLOGI never reached the fabric. Option B is wrong because a duplicate WWPN would cause a login rejection or conflict, but again the host would still attempt FLOGI and appear briefly; the absence from the database suggests no FLOGI was processed. Option D is wrong because VSAN mismatch would cause the FLOGI to be dropped or rejected, but the host would still attempt to send a FLOGI and the interface would show some activity; the complete lack of appearance points to a port-mode issue.

Option E is wrong because HBA compatibility with NPV is not a common restriction; NPV is designed to work with standard Fibre Channel HBAs, and incompatibility would manifest as link issues, not a silent failure to appear in the flogi database.

52
MCQmedium

Refer to the exhibit. The interface shows CRC errors. What is the most likely cause of these errors?

A.Insufficient buffer credits for the distance.
B.The port is configured as F port but should be E port.
C.Speed mismatch between the ports.
D.Faulty SFP or fiber cable.
AnswerD

CRC errors are typically caused by signal degradation from hardware.

Why this answer

CRC errors often indicate physical layer issues such as optics or cable problems. Option B is correct. Option A is wrong because credit starvation would show credit timeouts.

Option C is wrong because speed mismatch would cause link failures. Option D is wrong because the port is operational mode F.

53
MCQhard

On a Cisco MDS 9700, an engineer configures an FC port channel with 4 member interfaces. The connected storage array also supports port channels. Which load-balancing algorithm provides the best distribution of I/O when the array uses multiple LUNs per target?

A.Source ID (SID) and Destination ID (DID)
B.Source and destination port ID
C.Source FC ID (OXID) and destination FC ID (RXID)
D.Source and destination WWPN
AnswerC

Using exchange IDs (OXID/RXID) provides per-exchange load balancing, spreading I/O across LUNs better.

Why this answer

Option B is correct because per-exchange load balancing distributes I/Os between same initiator-target pair, ideal for multiple LUNs. Other options may not distribute well.

54
Matchingmedium

Match each Cisco NX-OS feature to its description.

Drag a concept onto its matching description — or click a concept then click the description.

Concepts
Matches

Virtual device context for partitioning a switch

Virtual routing and forwarding for network segmentation

Virtual PortChannel for multi-homing with loop prevention

Fabric Extender for remote linecard connectivity

Power-On Auto Provisioning for zero-touch deployment

Why these pairings

These features are essential for NX-OS configuration and management.

55
MCQhard

Refer to the exhibit. A server with WWPN 10:00:00:00:c9:2b:1a:5f is zoned to two storage ports in zone Server1_Storage1 and to one storage port in zone Server1_Storage2. The server can access the LUNs through the first zone but not through the second. What is the most likely cause?

A.The second zone does not include the second storage controller's port
B.The storage port 20:00:00:00:c9:2b:1a:6c is in a different VSAN
C.The zone set has not been activated
D.The server is not allowed to be in multiple zones
AnswerA

The server may need both storage paths to access LUNs; missing port causes no path.

Why this answer

The second zone Server1_Storage2 only has the server and one storage port. The server should have also a member for the second storage controller path. Option D best fits: the zone is missing the other storage controller's WWPN.

Option A (zone set activation) unlikely as the other zone works. Option B (multiple zones per server) is fine. Option C (VSAN mismatch) not indicated.

56
Multi-Selectmedium

A storage administrator is troubleshooting a Fibre Channel SAN where initiators cannot log in to a target. The administrator verifies that the VSAN is configured correctly and that zoning is in place. Which two additional checks should be performed to resolve the issue?

Select 2 answers
A.Ensure NPIV is enabled on the F-port.
B.Confirm that FCID persistence is not enabled with invalid static FCIDs.
C.Verify that port security is not blocking the initiator WWPN.
D.Verify the FCoE VLAN ID matches on both ends.
E.Check that LUN masking has been applied on the target.
AnswersB, C

Invalid static FCID persistence can cause login failures if the FCID is already in use or conflicting.

Why this answer

In a Fibre Channel SAN, FCID persistence assigns a specific FCID to a device each time it logs in. If an invalid static FCID is configured (e.g., an FCID that conflicts with another device or is outside the allowed range), the initiator may fail to log in because the switch cannot assign the requested address. This is a common cause of login failures even when VSAN and zoning are correctly configured.

Exam trap

Cisco often tests the distinction between fabric-level login issues (like FCID persistence or port security) and storage-level issues (like LUN masking), leading candidates to incorrectly select LUN masking as a cause of login failure.

57
MCQmedium

A Fibre Channel fabric has multiple initiators and targets. The engineer wants to ensure that only specific hosts can access specific storage volumes. Which zoning practice is most secure?

A.Zoning by storage array aliases
B.Single-initiator zoning with WWPNs
C.Using VSANs instead of zones
D.Soft zoning with domain/port IDs
AnswerB

Correct: Single-initiator zoning is the most secure practice.

Why this answer

Option A is correct because single-initiator zoning restricts each initiator to its own zone, preventing unauthorized access. Option B is incorrect because zone aliases don't affect security. Option C is incorrect because VSANs provide broad isolation, not granular.

Option D is incorrect because soft zoning is less secure (no RSCN filtering).

58
MCQmedium

A server administrator reports that a newly provisioned application server cannot access its LUN on the storage array. The SAN zoning uses WWPNs. The administrator verifies that the server's HBA WWPN is correctly zoned with the storage port's WWPN. Which additional check should the engineer perform to isolate the issue?

A.Confirm that VSAN interop is enabled on the MDS switch
B.Verify that the zone set is activated and that the zones are in the active zone set
C.Ensure that the switch port is configured in F mode and local switching is enabled
D.Check whether FCIP is configured on the storage array
AnswerB

Zone set must be active for zoning to take effect.

Why this answer

Even if the WWPNs are correctly configured in the zone, the zone set must be activated for the zoning to take effect. Without activation, the zone configuration remains in the pending or offline zone set, and the Fibre Channel fabric will not enforce the access controls. The engineer should verify that the zone set is activated and that the zones appear in the active zone set using commands like 'show zoneset active' on the MDS switch.

Exam trap

Cisco often tests the distinction between configuring a zone and activating the zone set, because candidates assume that creating a zone automatically applies it to the fabric.

How to eliminate wrong answers

Option A is wrong because VSAN interop is not a standard feature on MDS switches; VSANs are isolated by default and inter-VSAN routing (IVR) would be needed for communication between VSANs, but this is unrelated to a LUN access issue within the same VSAN. Option C is wrong because switch ports in F mode (fabric port) are used to connect to N-port devices like HBAs, and local switching is enabled by default on MDS switches; neither setting would prevent a correctly zoned HBA from accessing its LUN. Option D is wrong because FCIP is used for extending Fibre Channel over IP networks, not for local SAN connectivity; it is irrelevant to a server accessing its LUN on a directly connected storage array.

59
MCQmedium

A medium-sized enterprise has a Cisco UCS environment with two Fabric Interconnects (FIs) in a cluster. There are 10 blade servers, each with a VIC 1340 adapter. The SAN consists of two MDS 9148S switches in a VSAN for storage. Each server is configured with two vHBAs (primary and secondary) connecting to the SAN via the FIs. Recently, after a firmware upgrade on the MDS switches, several servers are unable to boot from SAN. The storage administrator confirms that the storage array LUNs are accessible from the MDS switches. The UCS administrator reports that the vHBAs show a 'link down' status on the FI. Which action should be taken to resolve the issue?

A.Reconfigure the vHBAs on the UCS Manager with new WWPNs.
B.Check the storage array LUN masking and re-apply LUN access.
C.Verify the active zone set on the MDS switches and re-activate it if necessary.
D.Downgrade the MDS firmware to the previous version.
AnswerC

Firmware upgrade may deactivate the zone set.

Why this answer

The 'link down' status on the vHBAs indicates that the Fibre Channel fabric is not properly delivering the FLOGI (Fabric Login) response to the initiators. Since the storage LUNs are accessible from the MDS switches, the issue is likely that the active zone set was deactivated or not saved after the firmware upgrade, preventing the vHBAs from logging into the fabric. Re-activating the zone set on the MDS switches will re-establish the FC zones and allow the vHBAs to complete FLOGI and resume boot from SAN.

Exam trap

Cisco often tests the distinction between storage array LUN masking (target-side) and FC fabric zoning (switch-side); the trap here is that candidates assume a 'link down' on the vHBA must be a physical or HBA configuration issue, when in fact it is a fabric-level problem caused by missing or inactive zone sets after a switch upgrade.

How to eliminate wrong answers

Option A is wrong because changing WWPNs would require re-zoning and re-masking on both the MDS and storage array, and the problem is not related to WWPN exhaustion or duplication. Option B is wrong because the storage administrator confirmed LUNs are accessible from the MDS, so LUN masking is already correct; the issue is at the FC fabric layer, not the storage array. Option D is wrong because downgrading firmware is a disruptive workaround that does not address the root cause (zone set activation state), and the problem is likely a configuration persistence issue after upgrade, not a firmware bug.

60
MCQhard

An engineer is designing a SAN to connect hosts to two storage arrays for redundancy. The hosts are dual-attached to two MDS switches. Each storage array has two controllers, each with a single FC port. The engineer wants to avoid a single point of failure and ensure that each host can reach both storage controllers. Which design should be used?

A.Connect both HBAs of each host to the same switch, and create zones that include both HBAs and both storage ports.
B.Connect each host HBA to a separate switch, and zone each HBA to one storage controller port.
C.Use NPV mode to simplify connectivity.
D.Connect each host HBA to a different switch, and zone each HBA to a specific storage controller, using zones that cross VSANs.
E.Connect each host HBA to a different switch, and zone each HBA to both storage controller ports.
AnswerE

This provides redundant paths at every layer: HBA, switch, and controller.

Why this answer

Option E is correct because it provides full redundancy: each host HBA connects to a different MDS switch, and each HBA is zoned to both storage controller ports. This ensures that if a switch, HBA, or storage controller fails, the host can still reach at least one storage controller via the remaining path. The dual-zoning per HBA allows each host to access both controllers without a single point of failure, meeting the requirement for host-to-controller reachability.

Exam trap

Cisco often tests the misconception that connecting both HBAs to the same switch is acceptable for redundancy, but the trap here is that a single switch failure would cause complete loss of connectivity, so each HBA must be on a different switch to eliminate that single point of failure.

How to eliminate wrong answers

Option A is wrong because connecting both HBAs of each host to the same switch creates a single point of failure at the switch level; if that switch fails, the host loses all connectivity. Option B is wrong because zoning each HBA to only one storage controller port means that if that specific controller port fails, the host cannot reach the other controller, violating the requirement for full redundancy. Option C is wrong because NPV (N_Port Virtualization) mode is used to simplify Fibre Channel fabric connectivity by reducing domain IDs, but it does not address the zoning or redundancy requirements for host-to-controller access.

Option D is wrong because zoning across VSANs is unnecessary and adds complexity; VSANs are used for isolation, not for providing redundant paths, and this design does not ensure each host can reach both storage controllers.

61
Multi-Selectmedium

An engineer is tuning performance for a storage network. Which two practices improve FC SAN performance?

Select 2 answers
A.Disabling flow control.
B.Using single-initiator zoning.
C.Ensuring adequate buffer credits.
D.Enabling broadcast zoning.
E.Setting fabric login timeout to the maximum.
AnswersB, C

Reduces inter-initiator traffic.

Why this answer

Single-initiator zoning (Option B) reduces inter-switch link (ISL) traffic and prevents fabric-wide disruptions by ensuring that only one initiator can communicate with a specific set of target ports. This minimizes the number of Registered State Change Notifications (RSCNs) and simplifies troubleshooting, directly improving FC SAN performance by reducing control-plane overhead.

Exam trap

Cisco often tests the misconception that disabling flow control improves performance by reducing overhead, but in FC SANs, flow control (BB_Credit) is mandatory for lossless operation, and disabling it causes frame drops and retransmissions.

62
MCQeasy

A new storage administrator is configuring LUN masking on a Cisco MDS switch. The storage array presents two LUNs to the fabric with the same LUN ID (0) but to different target ports. The administrator wants to ensure that a specific host can access both LUNs. The host is connected to a single HBA port. The host will see both target ports in the same zone. After zoning, the host discovers both target ports but only sees the first LUN. The show flogi database shows the host's pWWN with two FC IDs assigned. What is the most likely issue?

A.The zone is misconfigured
B.The host is not configured for multipathing
C.There is a LUN ID conflict
D.The target LUNs are not masked to the host's pWWN
AnswerD

The storage array likely has LUN masking that only allows the first LUN for this host.

Why this answer

The host discovers both target ports via FLOGI but only sees the first LUN because the storage array has not been configured to mask the LUNs to the host's pWWN. LUN masking is an array-side access control that determines which initiator WWNs can see which LUNs; without it, the array defaults to presenting only the first LUN (LUN 0) to any initiator. The zone is correctly configured (both target ports are in the same zone and the host sees them), and the LUN ID conflict is irrelevant because the LUNs are on different target ports, so they can share the same LUN ID without conflict.

Exam trap

Cisco often tests the distinction between zoning (fabric-level connectivity) and LUN masking (array-level access control), trapping candidates who assume zoning alone grants LUN visibility.

How to eliminate wrong answers

Option A is wrong because the zone is correctly configured: the host discovers both target ports, proving the zone includes both target ports and the host's pWWN. Option B is wrong because multipathing is a host-side driver configuration that affects path failover and load balancing, not the visibility of LUNs; the host already sees both target ports, so multipathing would not cause one LUN to be hidden. Option C is wrong because a LUN ID conflict occurs when two LUNs with the same ID are presented to the same initiator from the same target port, but here the LUNs are on different target ports, so sharing LUN ID 0 is allowed and does not cause one LUN to disappear.

63
Multi-Selectmedium

Which TWO benefits does NPIV (N_Port ID Virtualization) provide in a Fibre Channel SAN? (Choose two.)

Select 2 answers
A.Enhances security by isolating traffic at the port level
B.Enables Fibre Channel connectivity for virtual machines
C.Increases throughput by aggregating bandwidth
D.Allows multiple VSANs on a single link
E.Reduces the number of physical ports needed for virtualized servers
AnswersB, E

Correct: VMs can have dedicated WWPNs.

Why this answer

Options A and D are correct. NPIV allows multiple virtual ports on a single physical port, reducing cabling and enabling virtualization. Option B is incorrect because NPIV does not improve security.

Option C is incorrect because NPIV does not create separate VSANs. Option E is incorrect because NPIV does not increase throughput.

64
MCQeasy

Which feature allows a Fibre Channel switch to use multiple links between two switches as a single logical link?

A.NPIV
B.NPV
D.SPAN
E.FCIP
AnswerC

SAN port channels bundle multiple ISL links into a single logical link.

Why this answer

SAN port channel (C) is correct because it allows multiple physical Fibre Channel links between two switches to be aggregated into a single logical link, providing load balancing and redundancy. This is achieved by bundling up to 16 physical ISLs into one logical interface, using a proprietary hashing algorithm to distribute frames across the member links while maintaining in-order delivery.

Exam trap

Cisco often tests the distinction between SAN port channel (link aggregation) and NPV/NPIV (virtualization features), so the trap here is confusing link aggregation with virtualization or tunneling protocols like FCIP.

How to eliminate wrong answers

Option A is wrong because NPIV (N_Port ID Virtualization) allows a single Fibre Channel N_Port to register multiple FC IDs, enabling virtualization, but it does not aggregate links. Option B is wrong because NPV (N_Port Virtualization) allows a switch to behave as a host to upstream switches, reducing domain IDs, but it does not bundle links. Option D is wrong because SPAN (Switched Port Analyzer) is a Cisco feature for mirroring traffic to a monitor port, not for link aggregation.

Option E is wrong because FCIP (Fibre Channel over IP) tunnels FC frames over IP networks for long-distance connectivity, but it does not combine multiple physical links into a single logical link between two FC switches.

65
Multi-Selectmedium

Which TWO statements about Fibre Channel zoning are correct? (Choose two.)

Select 2 answers
A.Zoning can be used to prevent unauthorized access to storage targets.
B.Zoning is required to increase the distance between a host and storage.
C.Zoning can only be applied within a single VSAN.
D.Zoning is used to load balance traffic across multiple paths.
E.Hard zoning uses ACLs to enforce membership at the frame level.
AnswersA, E

Zoning restricts communication between specific ports.

Why this answer

Zoning is used for security and access control. Option A is correct because zoning restricts which devices can communicate. Option B is wrong because zoning does not provide load balancing.

Option C is correct because hard zoning enforces access at the switch level even if the initiator attempts to bypass. Option D is wrong because zoning is not for distance; flow control deals with distance. Option E is wrong because zoning is per VSAN, but can be across VSANs if using inter-VSAN routing, but not inherently.

66
MCQmedium

An administrator is troubleshooting a performance issue in an FC SAN. The initiator and target are in the same VSAN. The link is 16 Gbps but throughput is only 4 Gbps. The engineer checks the BB_Credit utilization and sees a high count of BB_Credit zero. What is the most likely cause?

A.Congestion on the target port
B.High link error rates
C.Incorrect zoning configuration
D.Buffer-to-buffer credit exhaustion
AnswerD

BB_Credit zero means the port has run out of credits, causing pauses and low throughput.

Why this answer

BB_Credit zero indicates buffer-to-buffer credit exhaustion, which pauses transmission and reduces throughput. This is typically due to distance or small credit pool. Link errors would show CRC errors, congestion would cause other symptoms, and zoning is unrelated.

67
MCQmedium

A data center uses a Cisco MDS 9710 director with multiple line cards. The storage network includes several host servers connected to the director via 16 Gbps FC connections. Recently, the engineering team deployed a new storage array that supports 32 Gbps FC. To take advantage of the higher speed, they upgraded the host HBAs to 32 Gbps. However, after the upgrade, some hosts are experiencing intermittent connection drops. The team notices that when a host disconnects, it takes approximately 30 seconds to reconnect. The link lights on the host and switch ports are green. The switch logs show 'VSAN 100: Port fc1/1 is down (link failure)' messages. No other errors are reported. The MDS line cards support 32 Gbps, and the ports are configured with the 'speed 32000' command. What is the most likely cause of the intermittent drops?

A.Insufficient buffer credits on the host ports
B.Incompatible SFP+ modules
C.Inconsistent zoning configuration
D.Mismatched port speed configuration between host and switch
AnswerD

A mismatch (e.g., host at 16 Gbps, switch at 32 Gbps) can cause intermittent link drops.

Why this answer

The most likely cause is a speed mismatch between the host HBA and the switch port. Although the switch port is set to 32 Gbps, the HBA might be set to auto-negotiate or default to 16 Gbps, causing instability. The 30-second reconnect time is typical of speed negotiation failures.

Incompatible SFPs would cause persistent link failure, buffer credits cause throughput drops but not disconnects, and zoning would block connectivity.

68
MCQmedium

An engineer is troubleshooting a SAN performance issue. The show interface counters command shows high output discard counts on a particular Fibre Channel interface. What is the most likely cause?

A.High CRC errors on the link.
B.Insufficient buffer credits on the transmitting port.
C.Insufficient bandwidth due to latency.
D.Mismatched zone configurations.
AnswerB

Output discards happen when the port runs out of buffer credits.

Why this answer

Output discards on an FC interface typically indicate that the port is out of buffer credits and frames are being discarded. Option A is wrong because CRC errors are different. Option B is wrong because high latency doesn't directly cause discards.

Option D is wrong because zoning mismatch would cause login issues, not discards.

69
MCQeasy

A company is deploying a new storage array with dual controllers. Each controller has two 16 Gbps Fibre Channel ports. The engineer wants to connect each controller to two separate MDS switches for redundancy. What is the recommended port type configuration on the MDS switches for the storage-facing ports?

A.F port
B.Configure the port as auto to allow negotiation
C.NP port
D.E port
AnswerA

F ports connect N ports of end devices.

Why this answer

Storage array ports typically operate as target ports, so the switch ports should be configured as F ports (fabric ports). Option A is correct. Option B (E port) is for ISL.

Option C (NP port) is for NPV. Option D (auto) may work but not recommended.

70
MCQhard

A data center engineer is designing a storage network for a virtualized environment with 100 hosts and 50 storage arrays. Each host requires 4 Gbps of bandwidth to storage, and each storage array provides 8 Gbps. All devices use 16 Gbps FC links. What is the minimum number of 16 Gbps FC links required to support the total bandwidth demand without oversubscription?

A.50
B.200
C.100
D.25
AnswerD

25 links provide 400 Gbps of bandwidth (16 Gbps each) to meet total demand.

Why this answer

The total bandwidth demand from hosts is 100 hosts × 4 Gbps = 400 Gbps. Each storage array provides 8 Gbps, so total storage bandwidth is 50 arrays × 8 Gbps = 400 Gbps. Since all links are 16 Gbps FC, the minimum number of links required to carry 400 Gbps without oversubscription is 400 / 16 = 25 links.

This assumes full-duplex links and no oversubscription in the fabric.

Exam trap

Cisco often tests the concept of aggregate bandwidth versus per-device bandwidth, leading candidates to incorrectly multiply host count by link speed or storage array count by link speed instead of summing the total bandwidth demand and dividing by link speed.

How to eliminate wrong answers

Option A (50) is wrong because it incorrectly assumes each storage array needs a dedicated 16 Gbps link, ignoring that the total bandwidth demand is 400 Gbps and 50 links would provide 800 Gbps, which is overkill and not minimal. Option B (200) is wrong because it mistakenly multiplies the number of hosts (100) by the per-host bandwidth (4 Gbps) and then divides by 8 Gbps (storage array bandwidth) or confuses link count with host count, leading to a gross overestimate. Option C (100) is wrong because it assumes each host requires a dedicated 16 Gbps link, ignoring that the aggregate demand is 400 Gbps and 100 links would provide 1600 Gbps, far exceeding the need.

71
Multi-Selecthard

Which THREE of the following are best practices for Fibre Channel zoning on Cisco MDS switches?

Select 3 answers
A.Make zones as specific as possible, avoiding device inclusion across multiple zones unnecessarily
B.Use WWPN-based zoning instead of port-based zoning
C.Always activate the zone set using the 'zone activate' command in configuration mode
D.Use hard zoning (access control list enforcement)
E.Use soft zoning with name server response filtering
AnswersA, B, C

Specific zones reduce complexity and security risks.

Why this answer

Zoning best practices: use WWPN zoning for stability, use read-only zone sets for audit, and minimize zone aliasing for clarity. Option A (hard zoning) is correct but not a best practice per se; hard zoning is default. The best practices are options B, C, and D.

Option E (soft zoning) is less secure.

72
MCQhard

A large financial institution operates a dual-fabric Fibre Channel SAN with two separate MDS 9710 directors. Each fabric has multiple storage arrays and hundreds of hosts. The SAN is configured with VSANs to isolate different environments (production, development, backup). Recently, the backup VSAN has been experiencing slow performance during backup windows. Analysis shows that the ISLs between the directors in the backup VSAN are heavily utilized (near 100%) while other ISLs have spare capacity. The backup traffic consists of large sequential reads and writes. The SAN administrator has confirmed that there are no CRC errors or link issues. The backup VSAN uses a single 16 Gbps ISL. Which of the following is the best solution to improve backup performance?

A.Add an additional 16 Gbps ISL and configure a port channel for the backup VSAN.
B.Reduce the buffer credit count on the backup VSAN ISLs to reduce latency.
C.Enable QoS to prioritize backup traffic over other traffic.
D.Implement IVR to route backup traffic through the other fabric.
AnswerA

Increases bandwidth and load balancing.

Why this answer

Adding an additional 16 Gbps ISL and configuring a port channel for the backup VSAN increases the available bandwidth for backup traffic, which consists of large sequential reads and writes that can fully utilize the link. Port channels provide load balancing across member links based on source/destination IDs, effectively distributing the backup traffic and reducing congestion on the single ISL. This directly addresses the near-100% utilization without introducing complexity or relying on other fabrics.

Exam trap

Cisco often tests the misconception that QoS or buffer tuning can solve bandwidth saturation issues, but the core problem here is insufficient aggregate bandwidth, which only adding physical links (via port channels) can resolve.

How to eliminate wrong answers

Option B is wrong because reducing buffer credits on the ISL would actually increase latency and potentially cause frame drops, worsening performance, especially for long-distance links; buffer credits are used to absorb link latency, not to reduce it. Option C is wrong because QoS prioritization does not increase available bandwidth; it only reorders traffic, and since backup traffic is already the only traffic on that VSAN, prioritizing it would have no effect on the high utilization. Option D is wrong because IVR (Inter-VSAN Routing) would route backup traffic through the other fabric, but that fabric's ISLs are also shared with other VSANs and may not have spare capacity; moreover, IVR introduces additional complexity and potential security risks without guaranteeing improved performance, and the problem is bandwidth scarcity within the backup VSAN itself.

73
Multi-Selecthard

Which THREE conditions can cause Fibre Channel buffer credit starvation? (Choose three.)

Select 3 answers
A.Frequent CRC errors causing retransmissions
B.Long-distance links with insufficient credits allocated
C.High oversubscription ratio on the ISL
D.Multiple VSANs configured on the same trunk
E.Inadequate number of credits allocated to the port
AnswersA, B, E

Correct: Retransmissions consume credits without releasing them.

Why this answer

Options A, C, and E are correct. Long distances require more credits; link errors cause credits to be consumed; small credit pools limit available credits. Option B is incorrect because oversubscription affects bandwidth, not credits.

Option D is incorrect because multiple VSANs don't directly starve credits.

74
MCQhard

During a SAN migration, an engineer connects new storage to an existing MDS switch. The new storage array is configured with WWPNs that were previously used by decommissioned servers. After zoning is updated, some servers fail to see the correct LUNs. What is the most likely cause?

A.The NPV feature is enabled on the switch causing proxy login issues.
B.Duplicate WWPNs exist in the fabric, causing device login conflicts.
C.The new storage is not in the same VSAN as the servers.
D.The switch is running an older firmware that does not support the new storage.
AnswerB

Reusing WWPNs without clearing the old entries leads to duplicate registrations.

Why this answer

Duplicate WWPNs cause confusion in the fabric. Option A is correct. Option B is wrong because zoning was updated.

Option C is wrong because NPV does not cause LUN issues. Option D is wrong because FLOGI would fail if there was a conflict.

75
MCQmedium

A storage administrator configures a new Cisco MDS switch and enables NPV mode. However, the upstream switch shows the NPV switch as an end device instead of a switch. What is the most likely reason?

A.The upstream switch port is configured as an E port.
B.NPIV is not enabled on the upstream switch.
C.The NPV switch has a domain ID that conflicts with the upstream switch.
D.The NPV switch is configured with N port mode.
AnswerB

Without NPIV, the upstream switch treats the NPV device as a regular end device.

Why this answer

NPV mode requires the upstream switch to have NPIV enabled. Option C is correct. Option A is wrong because NPV switches do not have their own domain ID.

Option B is wrong because F ports are correct. Option D is wrong because N port is initiator mode; NPV uses NP ports.

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