350-601 Storage Network Practice Test 9 — 15 Questions

Question 1

Which TWO are required for FCoE communication on a Nexus switch configured as an FCF? (Choose two.)

Accepted Answer

A dedicated FCoE VLAN. In an FCoE FCF (Fabric Connect) configuration on a Nexus switch, a dedicated FCoE VLAN is required to carry FCoE traffic. This VLAN must be separate from standard Ethernet VLANs to prevent FCoE frames from being processed as regular Ethernet frames. Additionally, DCBX (Data Center Bridging Exchange) must be used to negotiate and enable Priority Flow Control (PFC) on the link, ensuring lossless behavior for FCoE traffic.

Answer

Jumbo frame support on the VLAN

Answer

VSAN configuration for the FCoE VLAN

Answer

NPV enabled on the switch

Question 2

A storage administrator notices that a newly deployed Fibre Channel initiator cannot log in to the SAN switch. The switch is configured for NPV mode. Which condition is most likely causing the issue?

Accepted Answer

NPIV is disabled on the upstream switch.. In NPV mode, the switch acts as a transparent proxy, forwarding FLOGI requests from initiators to the upstream NPIV-capable core switch. If NPIV is disabled on the upstream switch, it will reject the FLOGI because it cannot register multiple N-Port IDs on a single physical link, causing the initiator to fail login.

Answer

The initiator is not using a device alias.

Answer

The switch is configured for NPIV mode instead of NPV.

Answer

The switch port is configured as an E port.

Question 3

An engineer is designing a SAN extension over a WAN link using FCIP. The link has high latency (50 ms RTT). Which configuration is most critical to maintain performance?

Accepted Answer

Configure a large TCP window size.. FCIP encapsulates Fibre Channel frames over TCP/IP. High latency (50 ms RTT) means the TCP sender must wait longer for acknowledgments, which can stall the connection if the TCP window is too small. A large TCP window size (e.g., using window scaling per RFC 1323) allows more data to be in flight before requiring an ACK, thereby maintaining throughput and preventing performance collapse on high-latency WAN links.

Answer

Enable compression on the FCIP tunnel.

Answer

Increase the buffer-to-buffer credits.

Answer

Reduce the TCP MSS to 512 bytes.

Question 4

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?

Accepted Answer

Duplicate WWPNs exist in the fabric, causing device login conflicts.. The new storage array is configured with WWPNs that were previously used by decommissioned servers. When these WWPNs are introduced into the fabric, the switch detects duplicate WWPNs because the fabric name server still holds the old entries (or the devices are still logged in). This causes login conflicts, preventing the servers from correctly discovering the LUNs. The correct answer is B.

Answer

The NPV feature is enabled on the switch causing proxy login issues.

Answer

The new storage is not in the same VSAN as the servers.

Answer

The switch is running an older firmware that does not support the new storage.

Question 5

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

Accepted Answer

Use LUN zoning to map the initiator to a specific LUN ID.. LUN zoning (also known as LUN masking) allows the administrator to map a specific initiator to a particular LUN ID on a target, ensuring that the initiator can only access that single LUN. This is achieved by configuring access control at the storage array level, typically using the target's LUN masking feature, which restricts visibility to only the assigned LUN. Unlike WWPN zoning, which controls fabric-level access, LUN zoning provides granular per-LUN access control.

Answer

Implement soft zoning based on domain IDs.

Answer

Configure a zone with the initiator WWPN and the target WWPN.

Answer

Place the initiator and target in different VSANs.

Question 6

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?

Accepted Answer

Increase the number of buffer credits on the ISL.. High buffer credit starvation counters on an inter-switch link (ISL) indicate that the switch is running out of buffer credits to send frames, causing pauses in transmission. Increasing the number of buffer credits on the ISL directly addresses this by providing more credit pool for the link, allowing the switch to send more frames before needing acknowledgment, thus reducing starvation and improving throughput.

Answer

Change the ISL port mode from E to F.

Answer

Reduce the ISL speed to 1 Gbps.

Answer

Enable QoS to prioritize buffer credit recovery.

Question 7

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?

Accepted Answer

show vlan fcoe. The FCoE Initialization Protocol (FIP) discovery phase relies on FCoE VLANs being properly configured and active on the switch. The 'show vlan fcoe' command displays the FCoE VLANs and their status, which is the first place to check when FIP discovery fails because the server must be in the correct FCoE VLAN to discover the FCF (FCoE Forwarder). If the FCoE VLAN is missing or not mapped correctly, FIP discovery will fail.

Answer

show npv status

Answer

show dcbx parameters

Answer

show priority-flow-control

Question 8

A data center architect is designing a SAN with two MDS switches using VSANs. Which method ensures traffic isolation between departments while allowing sharing of a tape library?

Accepted Answer

Create separate VSANs for each department and a shared VSAN for the tape library with inter-VSAN routing (IVR).. It uses separate VSANs to isolate each department's traffic at Layer 2, while inter-VSAN routing (IVR) selectively allows the tape library to be shared across VSANs without merging them. IVR enables controlled communication between specific initiators and targets in different VSANs, preserving isolation for all other traffic.

Answer

Use FCIP tunnels for each department.

Answer

Create separate VSANs and merge them for the tape library.

Answer

Use one VSAN for all departments and one zone for each department.

Question 9

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?

Accepted Answer

NPIV is not enabled on the upstream switch.. When NPV mode is enabled on a Cisco MDS switch, it operates as an N-port proxy, requiring the upstream Fibre Channel switch to support NPIV (N_Port ID Virtualization). NPIV allows multiple FC IDs to be assigned to a single N port, which is essential for the NPV switch to present multiple end devices behind a single physical link. Without NPIV enabled on the upstream switch, the NPV switch is treated as a single end device (like a server HBA) rather than as a switch fabric element.

Answer

The upstream switch port is configured as an E port.

Answer

The NPV switch has a domain ID that conflicts with the upstream switch.

Answer

The NPV switch is configured with N port mode.

Question 10

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?

Accepted Answer

Increase the buffer-to-buffer credit count on the link.. CRC errors are physical layer issues caused by signal integrity problems such as dirty connectors, wrong fiber type, or excessive distance. Increasing the buffer-to-buffer credit count adjusts flow control and does not address signal integrity, making it the least likely to resolve CRC errors. The other options—replacing with single-mode fiber if multimode is used, cleaning connectors, and verifying SFP+ optics—directly target physical layer issues and are more likely to help.

Answer

Replace the fiber cable with a single-mode fiber cable if multimode is used.

Answer

Clean all fiber connectors and inspect for damage.

Answer

Verify that the SFP+ optics match the fiber type and distance.

Question 11

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

Accepted Answer

Connecting a tape library that uses multiple LUNs to a single host.. 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.

Answer

Connecting an NPV switch to an upstream switch.

Answer

Enabling FCoE transit over a lossless Ethernet network.

Answer

Connecting two switches over an ISL.

Question 12

Which THREE factors must be considered when implementing FCIP for SAN extension over a WAN? (Choose three.)

Accepted Answer

Jitter and packet loss characteristics.. FCIP (Fibre Channel over IP) tunnels encapsulate Fibre Channel frames over IP networks. Jitter and packet loss directly cause Fibre Channel timeouts and retransmissions, severely impacting storage performance. Unlike Fibre Channel over dedicated links, WAN characteristics like jitter and loss must be explicitly accounted for in FCIP design.

Answer

VSAN configuration on the remote MDS switch.

Answer

Buffer-to-buffer credit count on the FCIP tunnel.

Question 13

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

Accepted Answer

show zone. 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.

Answer

show fcns database

Answer

show flogi database

Answer

show vsan membership

Question 14

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

Accepted Answer

Faulty SFP or fiber cable.. CRC errors indicate that frames are being received with invalid checksums, which is typically caused by physical-layer issues such as a faulty SFP module or damaged fiber cable. These errors occur when the cyclic redundancy check computed by the receiver does not match the CRC appended by the sender, pointing to corruption during transmission. In Fibre Channel storage networks, a faulty SFP or cable is the most common root cause of CRC errors, as they directly affect signal integrity.

Answer

Insufficient buffer credits for the distance.

Answer

The port is configured as F port but should be E port.

Answer

Speed mismatch between the ports.

Question 15

A large enterprise data center has a disaster recovery site 100 km away. The SAN uses two MDS 9700 series switches at each site, connected via a dedicated dark fiber. Each link operates at 16 Gbps with a round-trip time of 2 ms. Recently, backup jobs to the remote storage array have been failing with timeout errors. The backup server is local to Site A, but the backup target is in Site B. The link utilization never exceeds 40%, and no errors are reported on the interfaces. The engineer suspects the issue is related to buffer credits. The current buffer credit count on the ISL is 16. The engineer calculates that for 16 Gbps over 100 km (2 ms RTT), they need at least 200 credits to maintain full throughput. Which action is most appropriate to resolve the issue?

Accepted Answer

Increase the buffer-to-buffer credit count to 300 on the ISL interfaces.. The timeout errors during backup are caused by buffer credit starvation, as the current credit count of 16 is insufficient for the 100 km distance (2 ms RTT) at 16 Gbps. Increasing the buffer-to-buffer credit count to 300 ensures enough credits to maintain full throughput, preventing credit starvation and associated timeouts. Option B is correct because it directly addresses the insufficient credit count. Option A (NPIV) is unrelated to buffer credits; NPIV allows multiple N-port logins, not credit management. Option C (reducing speed to 8 Gbps) would lower throughput and is not optimal. Option D (FCIP) is unnecessary because the existing dark fiber provides a direct Fibre Channel link; FCIP is for IP-based transport and does not help with buffer credit issues.

Answer

Enable NPIV on the ISL ports to allow multiple logins.

Answer

Configure the ISL to operate at 8 Gbps to reduce the buffer credit requirement.

Answer

Implement FCIP over the existing dark fiber to offload buffer credit management.