Troubleshooting Cisco Data Center Infrastructure (DCIT) Practice Exam Test
Prepare confidently for the Troubleshooting Cisco Data Center Infrastructure (DCIT) certification exam with our expertly crafted practice test designed to simulate the real exam environment. This practice test offers a deep dive into essential topics such as Cisco UCS troubleshooting, Nexus switch configurations, Fabric Interconnect management, and data center networking protocols. Each question is carefully developed to reflect the latest industry standards and Cisco exam blueprints, ensuring you study the most relevant material.
Our DCIT practice test features detailed explanations for every question, helping you understand core concepts and learn from your mistakes. Whether you are a network engineer, data center professional, or IT specialist, this practice test will sharpen your troubleshooting skills, boost your confidence, and improve your chances of passing the exam on your first try.
Key Features:
400 updated multiple-choice questions aligned with the current DCIT exam objectives
In-depth explanations for every answer to reinforce learning
Covers critical topics including UCS service profiles, fabric extenders, VPC troubleshooting, FCoE, and Cisco Nexus switch operations
Realistic exam simulation to track your progress and identify areas for improvement
Suitable for both beginners and experienced professionals aiming to validate their data center troubleshooting expertise
Boost your career potential and validate your data center infrastructure troubleshooting skills with this indispensable practice test. Start practicing today and take a decisive step toward earning your Cisco DCIT certification!
Sample Questions and Answers
1. Which Cisco tool is primarily used for diagnosing hardware issues in Nexus switches?
A) Cisco Prime Infrastructure
B) Cisco DCNM
C) Cisco Nexus Dashboard Fabric Controller (NDFC)
D) Cisco Nexus Operating System (NX-OS) CLI
Answer: C) Cisco Nexus Dashboard Fabric Controller (NDFC)
Explanation: NDFC provides centralized fabric management and health diagnostics, including hardware monitoring for Nexus switches, making it ideal for hardware issue diagnosis.
2. When a Cisco Nexus switch port status shows “err-disabled,” what is the most likely cause?
A) The port is administratively shut down
B) The port has detected a security violation or error condition
C) The port is operational but not forwarding traffic
D) The port has been powered off remotely
Answer: B) The port has detected a security violation or error condition
Explanation: An err-disabled port means the switch has shut down the port due to a detected error such as BPDU guard violation or link flapping, requiring manual intervention or configured recovery.
3. Which command would you use to verify the status of a port channel on a Cisco Nexus switch?
A) show interface status
B) show port-channel summary
C) show vlan brief
D) show running-config interface port-channel
Answer: B) show port-channel summary
Explanation: This command displays the status, member interfaces, and operational state of port channels on Cisco Nexus switches.
4. What is the primary function of Cisco FabricPath in data center infrastructure?
A) Layer 2 multipath forwarding
B) Layer 3 routing protocol
C) Security policy enforcement
D) Virtual machine orchestration
Answer: A) Layer 2 multipath forwarding
Explanation: FabricPath enables multipath forwarding and scalable Layer 2 fabric, eliminating spanning-tree limitations and improving data center performance.
5. What troubleshooting step should be taken first if a server connected to a Nexus switch is unreachable?
A) Replace the server’s network card
B) Check physical connectivity and cabling
C) Upgrade the NX-OS firmware
D) Reset the server’s operating system
Answer: B) Check physical connectivity and cabling
Explanation: Physical layer issues are the most common cause of connectivity problems; always verify cables, transceivers, and physical connections first.
6. Which feature allows Cisco Nexus switches to detect loops caused by misconfigurations in the Layer 2 network?
A) Spanning Tree Protocol (STP)
B) Cisco FabricPath
C) VLAN Trunking Protocol (VTP)
D) Cisco TrustSec
Answer: A) Spanning Tree Protocol (STP)
Explanation: STP is designed to detect and prevent Layer 2 loops by blocking redundant links.
7. In a Nexus 9000 environment, which NX-OS command displays CPU utilization per process?
A) show processes cpu
B) show system resources
C) show cpu statistics
D) show processes memory
Answer: A) show processes cpu
Explanation: This command provides detailed CPU utilization statistics for individual processes on the device.
8. What is the default VDC resource allocation for CPU and memory on a Cisco Nexus switch?
A) 50% CPU and 50% memory
B) 75% CPU and 25% memory
C) 80% CPU and 20% memory
D) 100% CPU and 100% memory
Answer: A) 50% CPU and 50% memory
Explanation: By default, Cisco Nexus switches allocate 50% CPU and 50% memory to each VDC to ensure fair resource distribution.
9. What is a common cause of high packet drops on a Cisco Nexus switch interface?
A) Link negotiation mismatch
B) Incorrect VLAN assignment
C) High CPU utilization on the switch
D) Misconfigured QoS policies
Answer: D) Misconfigured QoS policies
Explanation: Incorrect QoS configurations can cause packet drops due to improper traffic shaping or policing.
10. Which of the following is true about Cisco OTV (Overlay Transport Virtualization)?
A) It requires a Layer 3 routing protocol on the underlay
B) It operates at Layer 2 only
C) It is a proprietary protocol for SAN fabrics
D) It cannot support multicast traffic
Answer: A) It requires a Layer 3 routing protocol on the underlay
Explanation: OTV encapsulates Layer 2 traffic over a Layer 3 network, requiring an underlay routing protocol for transport.
11. If a Nexus switch shows high memory usage but low CPU utilization, what could be the cause?
A) Memory leak or excessive buffer usage
B) Misconfigured routing protocol
C) Faulty CPU cores
D) Link aggregation errors
Answer: A) Memory leak or excessive buffer usage
Explanation: High memory usage with low CPU often points to memory leaks or buffering issues in queues.
12. Which command helps verify LLDP neighbor information on a Nexus switch?
A) show lldp neighbors
B) show cdp neighbors
C) show mac address-table
D) show interface status
Answer: A) show lldp neighbors
Explanation: LLDP (Link Layer Discovery Protocol) is used to discover directly connected neighbors and their capabilities.
13. In a Cisco UCS environment, what is the role of the Fabric Interconnect?
A) Acts as the central management point for UCS servers and networking
B) Provides storage area network (SAN) services
C) Acts as a backup firewall
D) Connects virtual machines within the hypervisor
Answer: A) Acts as the central management point for UCS servers and networking
Explanation: Fabric Interconnects provide unified management and connectivity for UCS blade servers and rack servers.
14. When troubleshooting a vPC peer link flapping issue, what is a likely cause?
A) Misconfigured VLAN allowed list on the trunk
B) Incorrect VDC assignment
C) Mismatched vPC domain IDs
D) High CPU usage on Nexus switches
Answer: A) Misconfigured VLAN allowed list on the trunk
Explanation: VLAN inconsistencies on the vPC peer link can cause link flapping and instability.
15. What is the purpose of the “show system internal interface” command in Nexus switches?
A) Display detailed interface statistics and internal counters
B) Show IP routing table
C) Show the switch’s uptime
D) Display hardware inventory
Answer: A) Display detailed interface statistics and internal counters
Explanation: This command helps troubleshoot low-level interface issues by showing internal stats.
16. Which protocol does Cisco Data Center Network Manager (DCNM) use to monitor SAN fabric health?
A) SNMP
B) Fibre Channel Protocol (FCP)
C) Fibre Channel Management Protocol (FCMP)
D) Fibre Channel Fabric Services (FC-FS)
Answer: D) Fibre Channel Fabric Services (FC-FS)
Explanation: FC-FS provides management and fabric services to monitor SAN health.
17. What NX-OS command would you use to clear the MAC address table on a Nexus switch?
A) clear mac address-table dynamic
B) clear interface mac-address
C) clear vlan mac-address-table
D) reset mac address-table
Answer: A) clear mac address-table dynamic
Explanation: This command clears all dynamically learned MAC addresses.
18. Which of the following could cause a Cisco Nexus switch to reload unexpectedly?
A) Power supply failure
B) Excessive logging enabled on all interfaces
C) Disabled VDCs
D) Using static MAC addresses
Answer: A) Power supply failure
Explanation: Hardware failures such as power supply issues often cause unexpected reloads.
19. Which NX-OS command shows the current version of the installed software?
A) show version
B) show running-config
C) show system image
D) show boot
Answer: A) show version
Explanation: This command displays NX-OS version, uptime, and hardware details.
20. What is the purpose of the Cisco Fabric Extender (FEX)?
A) Extends the access layer to reduce management complexity
B) Provides WAN connectivity
C) Acts as a firewall for data center traffic
D) Performs Layer 3 routing
Answer: A) Extends the access layer to reduce management complexity
Explanation: FEX devices extend Nexus switch ports to remote locations while being managed by a parent switch.
21. If a Cisco Nexus switch cannot ping a directly connected device, what is a likely first step in troubleshooting?
A) Verify interface status and VLAN membership
B) Reboot the switch immediately
C) Update NX-OS firmware
D) Change IP addressing scheme
Answer: A) Verify interface status and VLAN membership
Explanation: Confirm that interfaces are up and VLANs are correctly configured before advanced troubleshooting.
22. Which of the following describes the purpose of Cisco ACI health scores?
A) Quantify fabric operational health and connectivity issues
B) Measure server CPU utilization
C) Display virtual machine performance metrics
D) Monitor SAN traffic rates
Answer: A) Quantify fabric operational health and connectivity issues
Explanation: Health scores indicate overall fabric status and pinpoint potential problems in ACI environments.
23. How does Cisco Nexus support failover between multiple supervisors?
A) Stateful switchover (SSO)
B) Manual reboot on failure
C) Using VRRP on supervisor modules
D) STP blocking alternate supervisor
Answer: A) Stateful switchover (SSO)
Explanation: SSO allows seamless supervisor failover with minimal traffic disruption.
24. Which tool is best suited for real-time traffic analysis on Cisco Nexus switches?
A) SPAN (Switched Port Analyzer)
B) SNMP traps
C) Cisco Prime Infrastructure reports
D) Syslog server
Answer: A) SPAN (Switched Port Analyzer)
Explanation: SPAN mirrors traffic to a monitoring port for real-time packet analysis.
25. What could cause a Nexus switch interface to show as “down/down”?
A) Physical layer problem like cable or transceiver failure
B) Interface administratively up but no IP assigned
C) VLAN mismatch on trunk ports
D) Incorrect access control list (ACL)
Answer: A) Physical layer problem like cable or transceiver failure
Explanation: Both the physical link and line protocol need to be up; if both are down, it’s often a physical layer issue.
26. In Cisco DCNM, which dashboard view is best for checking overall fabric health?
A) Fabric Health Dashboard
B) Device Configuration
C) User Access Management
D) License Management
Answer: A) Fabric Health Dashboard
Explanation: This dashboard provides a summary of fabric-wide health and alerts.
27. Which NX-OS feature allows automation of repetitive troubleshooting tasks?
A) Embedded Event Manager (EEM)
B) Cisco DNA Center
C) Cisco ACI
D) Cisco TrustSec
Answer: A) Embedded Event Manager (EEM)
Explanation: EEM scripts automate actions based on triggers, aiding troubleshooting and event response.
28. How can you verify if a Cisco Nexus switch interface has been configured for LLDP?
A) show lldp interface <interface>
B) show interface <interface> description
C) show cdp interface <interface>
D) show running-config interface <interface>
Answer: A) show lldp interface <interface>
Explanation: This command displays LLDP configuration and status per interface.
29. What is the default administrative distance of OSPF on Cisco Nexus switches?
A) 110
B) 90
C) 120
D) 1
Answer: A) 110
Explanation: OSPF has a default administrative distance of 110 on Cisco devices.
30. During a troubleshooting session, you notice the Nexus switch logs show frequent “CPU watchdog” messages. What is the most likely cause?
A) The CPU is overloaded or stuck in a loop
B) Interface errors on Ethernet ports
C) Configuration mismatch on VLANs
D) Power supply instability
Answer: A) The CPU is overloaded or stuck in a loop
Explanation: CPU watchdog messages indicate the CPU is not responding timely due to high load or stuck processes.
31. Which NX-OS command would you use to check the status of VDCs configured on a Cisco Nexus switch?
A) show vdc brief
B) show vdc status
C) show vdc all
D) show vdc membership
Answer: A) show vdc brief
Explanation: This command provides a summary of all Virtual Device Contexts (VDCs) including their state and resource allocation.
32. In a Cisco Nexus environment, what is the effect of a port security violation on a switch port by default?
A) The port shuts down and goes into err-disabled state
B) The switch sends an SNMP trap and allows traffic
C) The port drops packets from the violating MAC but remains active
D) The switch forwards traffic normally without any action
Answer: A) The port shuts down and goes into err-disabled state
Explanation: By default, port security violation triggers err-disabled status to prevent potential security threats.
33. What does the command show tech-support collect on a Nexus device?
A) Comprehensive diagnostic and system information for troubleshooting
B) Only interface counters and error logs
C) Current configuration and running processes
D) Software version and license details only
Answer: A) Comprehensive diagnostic and system information for troubleshooting
Explanation: show tech-support collects various logs, config files, and diagnostic data useful for deep troubleshooting.
34. Which Cisco Nexus component is responsible for controlling Layer 2 switching forwarding?
A) Supervisory Engine
B) Line Card
C) Fabric Module
D) Management Module
Answer: B) Line Card
Explanation: Line cards handle Layer 2 and Layer 3 forwarding of packets on Nexus modular switches.
35. What is the recommended method to update NX-OS on a Nexus switch without interrupting traffic?
A) Use ISSU (In-Service Software Upgrade)
B) Perform a cold reboot after upgrade
C) Upload new image and reload immediately
D) Disable all interfaces before upgrade
Answer: A) Use ISSU (In-Service Software Upgrade)
Explanation: ISSU allows upgrading software without downtime on supported Nexus models.
36. Which protocol helps detect Layer 2 loops in Cisco Nexus switches apart from STP?
A) UDLD (Unidirectional Link Detection)
B) LACP
C) OSPF
D) VRRP
Answer: A) UDLD (Unidirectional Link Detection)
Explanation: UDLD detects unidirectional links and prevents Layer 2 loops caused by cable or hardware faults.
37. When monitoring interface errors, which counter indicates frames discarded due to buffer overflow?
A) Output drops
B) CRC errors
C) Input errors
D) Collisions
Answer: A) Output drops
Explanation: Output drops usually mean the egress buffer is full, causing frames to be discarded.
38. What command would you use to check the status of the fabric ports on a Cisco Nexus switch?
A) show interface brief
B) show interface fabric-port status
C) show module status
D) show system fabric status
Answer: B) show interface fabric-port status
Explanation: This command displays the operational status of fabric ports.
39. What is the default behavior of Cisco Nexus switches when VLAN pruning is enabled on a trunk?
A) VLANs not in use on a trunk link are not forwarded
B) All VLANs are forwarded regardless of pruning
C) Only native VLAN traffic is pruned
D) VLAN pruning disables trunk ports
Answer: A) VLANs not in use on a trunk link are not forwarded
Explanation: VLAN pruning restricts unnecessary VLAN traffic on trunk links, optimizing bandwidth.
40. Which NX-OS command would display the current CPU utilization and interrupt statistics?
A) show processes cpu history
B) show system resources
C) show processes cpu sorted
D) show processes cpu
Answer: D) show processes cpu
Explanation: Displays CPU usage including interrupt, kernel, and user time statistics.
41. What does the “show logging onboard” command do on Cisco Nexus switches?
A) Displays logs stored on the onboard flash memory
B) Shows syslog server configuration
C) Clears the logging buffer
D) Shows real-time logs only
Answer: A) Displays logs stored on the onboard flash memory
Explanation: Useful for viewing logs saved locally for troubleshooting.
42. When using vPC, what is the purpose of the vPC peer keepalive link?
A) To monitor the health of the peer switch and prevent split-brain conditions
B) To carry user data traffic between peer switches
C) To synchronize VLAN configurations
D) To forward broadcast traffic only
Answer: A) To monitor the health of the peer switch and prevent split-brain conditions
Explanation: The peer keepalive link checks connectivity between vPC peers and helps avoid dual-active scenarios.
43. If a Cisco Nexus switch interface shows “input errors” increasing, what is a probable cause?
A) Physical layer issues like bad cables or faulty transceivers
B) High CPU utilization on the switch
C) Misconfigured IP address
D) Disabled port security
Answer: A) Physical layer issues like bad cables or faulty transceivers
Explanation: Input errors generally indicate physical issues impacting inbound traffic integrity.
44. Which troubleshooting tool on a Cisco Nexus switch allows real-time packet capture?
A) Embedded Packet Capture (EPC)
B) Wireshark built-in
C) NetFlow Analyzer
D) Cisco Prime Infrastructure
Answer: A) Embedded Packet Capture (EPC)
Explanation: EPC lets you capture and analyze traffic directly on the switch without external tools.
45. In Cisco ACI, which component is responsible for policy enforcement?
A) Leaf switches
B) Spine switches
C) APIC Controller
D) End hosts
Answer: A) Leaf switches
Explanation: Leaf switches enforce policies configured via the APIC controller on ingress and egress traffic.
46. What command can you use to check the FabricPath neighbor table on a Cisco Nexus switch?
A) show fabricpath adj
B) show fabricpath neighbor
C) show fabricpath topology
D) show fabricpath interface
Answer: A) show fabricpath adj
Explanation: Displays FabricPath adjacency information and neighbor details.
47. Which NX-OS feature allows for persistent configurations to survive reloads and crashes?
A) Configuration rollback
B) Configuration archive
C) Startup configuration
D) Running configuration
Answer: C) Startup configuration
Explanation: The startup config is saved and loaded on reload to ensure persistent device configuration.
48. What does a “show interface transceiver” command display on a Nexus switch?
A) Details about SFP or QSFP module status and diagnostics
B) Interface speed and duplex settings
C) VLANs assigned to the interface
D) Current traffic statistics
Answer: A) Details about SFP or QSFP module status and diagnostics
Explanation: This command helps verify optical module health and capabilities.
49. If the output of show system internal flash shows very low free space, what issue might occur?
A) New files or logs cannot be saved, potentially impacting troubleshooting
B) The switch will immediately reboot
C) Interfaces will shut down automatically
D) CPU utilization will spike
Answer: A) New files or logs cannot be saved, potentially impacting troubleshooting
Explanation: Running out of flash space can prevent log storage or software upgrades.
50. What is the effect of enabling ‘storm control’ on a Nexus switch interface?
A) Limits the traffic rate of broadcast, multicast, or unicast to prevent network storms
B) Disables spanning tree on the port
C) Drops all traffic except DHCP
D) Enables VLAN pruning
Answer: A) Limits the traffic rate of broadcast, multicast, or unicast to prevent network storms
Explanation: Storm control protects the network from traffic floods that degrade performance.
51. How can you clear the error-disabled state on a Nexus switch port?
A) Manually re-enable the port with shutdown then no shutdown commands
B) Reload the switch only
C) Change the VLAN on the port
D) Clear the MAC address table
Answer: A) Manually re-enable the port with shutdown then no shutdown commands
Explanation: This resets the port state after error-disabled events.
52. What is a key benefit of using Cisco Nexus Distributed Firewall (DFW) in a data center?
A) Provides micro-segmentation with policy enforcement at the hypervisor level
B) Routes traffic between VLANs
C) Acts as a VPN concentrator
D) Performs WAN acceleration
Answer: A) Provides micro-segmentation with policy enforcement at the hypervisor level
Explanation: DFW enables fine-grained security policies to reduce lateral threat movement.
53. What is the purpose of the show cdp neighbors detail command?
A) Displays detailed Cisco Discovery Protocol info including IP address and platform of neighbors
B) Lists all VLANs configured on the switch
C) Shows current interface errors
D) Displays the switch running config
Answer: A) Displays detailed Cisco Discovery Protocol info including IP address and platform of neighbors
Explanation: Useful to identify connected Cisco devices and troubleshoot connectivity.
54. If a Cisco Nexus switch cannot join a vPC domain, what should you verify first?
A) vPC domain ID and peer keepalive link configuration
B) VLAN database
C) Routing protocol configuration
D) IP address of default gateway
Answer: A) vPC domain ID and peer keepalive link configuration
Explanation: Matching domain IDs and proper keepalive link setup are required for vPC formation.
55. What could cause a ‘port not forwarding’ problem on a Cisco Nexus switch?
A) Port is in spanning-tree blocking state
B) Port is assigned to the wrong VLAN
C) Port security violation occurred
D) All of the above
Answer: D) All of the above
Explanation: Any of these conditions can cause the port not to forward traffic.
56. What is the best way to troubleshoot multicast issues in Cisco Nexus environments?
A) Verify IGMP snooping and PIM configurations
B) Restart the multicast routing process
C) Disable spanning-tree on all switches
D) Increase interface bandwidth
Answer: A) Verify IGMP snooping and PIM configurations
Explanation: Proper multicast requires correct IGMP and PIM settings to manage group membership and routing.
57. Which command displays the firmware version of a Cisco UCS Fabric Interconnect?
A) show version
B) show firmware status
C) show system firmware
D) show ucs firmware
Answer: A) show version
Explanation: This provides detailed version info including firmware on UCS components.
58. What is the purpose of the show interface counters errors command on Cisco Nexus?
A) Displays error statistics for each interface
B) Clears interface error counters
C) Shows interface configuration
D) Displays interface status summary
Answer: A) Displays error statistics for each interface
Explanation: Helps identify physical or protocol issues by showing error counters.
59. Which protocol is used by Cisco Nexus switches for automatic discovery of neighboring switches?
A) Cisco Discovery Protocol (CDP)
B) LLDP
C) OSPF
D) STP
Answer: A) Cisco Discovery Protocol (CDP)
Explanation: CDP enables Cisco devices to discover and share info about neighbors.
60. What could be the cause if a Cisco Nexus switch shows inconsistent VLAN information in vPC?
A) VLAN configuration mismatch between vPC peers
B) Routing protocol misconfiguration
C) Incorrect IP addressing on management interface
D) STP disabled on the switch
Answer: A) VLAN configuration mismatch between vPC peers
Explanation: VLAN inconsistencies between peers can cause traffic forwarding issues in vPC setups.
