N10-009 Practice Test 20 — 15 Questions

Question 1

A network technician needs to retrieve the operating system and uptime information from a router for inventory purposes. Which protocol is specifically designed for network management and monitoring?

Accepted Answer

SNMP. SNMP (Simple Network Management Protocol) is the standard protocol specifically designed for network management and monitoring. It allows a network management station to query managed devices (like routers) for system information, including operating system version and uptime, via OIDs (Object Identifiers) in the MIB (Management Information Base).

Answer

SMTP

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HTTP

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FTP

Question 2

A network administrator is creating a new VLAN 50 on a switch. After creating the VLAN, the administrator notices that the switch does not send VLAN information to other switches in the network. Which of the following is the most likely reason?

Accepted Answer

VTP mode is set to transparent.. When VTP mode is set to transparent, the switch does not originate or forward VTP advertisements, so VLAN changes made on it are not propagated to other switches. This explains why VLAN 50 was created locally but not shared with the rest of the network.

Answer

The trunk link is not configured.

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The VLAN is not allowed on the trunk.

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STP is blocking the VLAN.

Question 3

A network technician is troubleshooting a switch port that shows a link light but has a high number of CRC errors in the interface statistics. The port is connected to a workstation's network interface card (NIC). Both devices are set to autonegotiate. What is the MOST likely cause of the CRC errors?

Accepted Answer

A: Duplex mismatch between the switch port and the workstation NIC. CRC errors indicate that frames received by the switch have failed the Ethernet frame check sequence (FCS) validation, meaning the data was corrupted during transmission. When both devices are set to autonegotiate but one fails to correctly negotiate the duplex setting, a duplex mismatch occurs: one side operates at full duplex while the other operates at half duplex. This causes collisions on the half-duplex side, which corrupts frames and generates CRC errors, while the full-duplex side does not detect collisions and retransmits, leading to a high error count.

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B: VLAN mismatch between the switch and the workstation

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C: Incorrect MTU setting on the switch port

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D: Broadcast storm from a loop in the network

Question 4

An organization needs to authenticate network administrators and control which commands each administrator can execute on routers and switches. The solution must support granular per-command authorization and encrypt the entire session. Which protocol is best suited for this requirement?

Accepted Answer

TACACS+. TACACS+ is the correct choice because it separates authentication, authorization, and accounting (AAA) functions, allowing granular per-command authorization on routers and switches. It encrypts the entire session, including the username, password, and all command traffic, unlike RADIUS which only encrypts the password. This makes TACACS+ ideal for environments requiring strict command-level control and full session encryption.

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RADIUS

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LDAP

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Kerberos

Question 5

A network administrator notices that several workstations on the network are receiving IP addresses from an unknown source, causing intermittent connectivity issues. The DHCP server is located in the server room and is the only authorized DHCP server. Which security feature should be implemented on the access switches to prevent rogue DHCP servers from distributing IP addresses?

Accepted Answer

DHCP Snooping. DHCP Snooping is the correct security feature because it filters untrusted DHCP messages on access switches. By configuring ports connected to end-user workstations as untrusted, the switch drops DHCP server responses (OFFER, ACK) received on those ports, preventing rogue DHCP servers from distributing IP addresses. This ensures only the authorized DHCP server in the server room can provide IP configurations.

Answer

Dynamic ARP Inspection

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IP Source Guard

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Port Security

Question 6

An organization uses OSPF as its interior gateway protocol in a multi-area design. After a core router failure, the network takes several seconds to reconverge. Which technology can be implemented to improve convergence speed?

Accepted Answer

Configure BFD (Bidirectional Forwarding Detection). BFD provides sub-second failure detection times (as low as 50 ms) independent of the routing protocol, allowing OSPF to reconverge much faster than relying on its default dead timer intervals. By detecting link failures in milliseconds, BFD triggers OSPF to immediately recalculate routes, drastically reducing the convergence delay after a core router failure.

Answer

Implement LSA throttling

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Enable OSPF fast hello timers

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Convert all areas to stub areas

Question 7

A network administrator has completed a scheduled firmware upgrade on a core switch. After verifying successful operation, which document should the administrator update to reflect the new firmware version?

Accepted Answer

Change management log. The change management log is the correct document to update because it records all modifications to the network, including firmware upgrades, along with details such as the date, reason, and new version. This log ensures compliance with ITIL change management processes and provides an audit trail for troubleshooting and future changes. Updating it after a successful firmware upgrade is a standard operational procedure to maintain accurate change history.

Answer

Network logical topology diagram

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Rack diagram

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Inventory management system

Question 8

A network administrator is creating documentation for a new data center. Which type of diagram is BEST for showing the logical relationships between VLANs and their associated subnets?

Accepted Answer

Logical topology diagram. A logical topology diagram is the correct choice because it illustrates how devices communicate across the network, including the mapping of VLANs to their associated IP subnets. This type of diagram abstracts away physical cabling and device locations to focus on Layer 2 and Layer 3 relationships, such as VLAN IDs, subnet masks, and default gateways. It is essential for documenting network segmentation and troubleshooting inter-VLAN routing.

Answer

Physical topology diagram

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Wiring diagram

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Rack elevation diagram

Question 9

A network administrator is creating a performance baseline for a new VoIP application. Which metric is most critical to monitor in order to ensure good voice quality for end users?

Accepted Answer

Latency. Latency is the most critical metric for VoIP voice quality because it directly impacts the conversational flow. High latency (above 150 ms one-way, per ITU-T G.114) causes noticeable delays that disrupt natural conversation, leading to user dissatisfaction. While jitter and bandwidth are important, latency is the primary factor that degrades the interactive experience.

Answer

Bandwidth utilization

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Jitter

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Packet loss

Question 10

A company is deploying VoIP phones and wants to ensure voice packets receive priority over data packets on the network. Which technology should be implemented on the switches and routers?

Accepted Answer

Quality of Service (QoS). Quality of Service (QoS) is the correct technology because it allows network devices to classify, mark, and prioritize voice traffic (e.g., using DSCP EF or CoS 5) over data traffic, ensuring low latency, jitter, and packet loss for VoIP. Switches and routers use QoS queuing mechanisms like LLQ or CBWFQ to guarantee bandwidth for voice packets, which is essential for real-time communications.

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VLAN

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Spanning Tree Protocol (STP)

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Power over Ethernet (PoE)

Question 11

A network administrator is creating a standard operating procedure for firmware upgrades. Which step should be performed FIRST according to best practices?

Accepted Answer

Test the firmware in a lab environment. According to best practices for firmware upgrades, the first step should always be to test the new firmware in a non-production lab environment that mirrors the production setup. This validates compatibility, identifies potential bugs, and ensures the upgrade process works without risking network downtime or data loss. Only after successful lab testing should you proceed to backup the current configuration and schedule the upgrade during a maintenance window.

Answer

Schedule the upgrade during a maintenance window

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Back up the current configuration

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Notify users of the planned outage

Question 12

A network technician is explaining the difference between a hub and a switch to a junior technician. Which statement correctly describes a key difference between these devices?

Accepted Answer

A hub sends frames out all ports except the incoming port; a switch sends frames only to the port with the matching MAC address.. B is correct because a hub operates at Layer 1 (physical layer) and blindly repeats electrical signals out all ports except the incoming port, creating a single collision domain. In contrast, a switch operates at Layer 2 (data link layer) and uses the MAC address table to forward frames only to the specific port associated with the destination MAC address, reducing unnecessary traffic and creating separate collision domains per port.

Answer

A hub operates at Layer 2, while a switch operates at Layer 1.

Answer

A hub uses MAC addresses to make forwarding decisions, while a switch uses IP addresses.

Answer

A hub creates a separate collision domain for each port, while a switch creates a single collision domain.

Question 13

A company is deploying a new wireless network for employee devices and wants to use the most secure encryption method currently available for WPA2/3. Which encryption standard should be used?

Accepted Answer

AES. AES (Advanced Encryption Standard) is the most secure encryption method available for WPA2 and WPA3. WPA2 mandates AES-CCMP, and WPA3 uses AES-GCMP, both of which are based on the AES block cipher, providing strong confidentiality and integrity. This makes AES the correct choice for the highest security in modern Wi-Fi deployments.

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WEP

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TKIP

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DES

Question 14

A network engineer needs to connect two network segments that use different physical media: one segment uses copper Ethernet and the other uses fiber optic. The device must forward frames based on MAC addresses and must not perform any routing. Which device should the engineer choose?

Accepted Answer

Bridge. A bridge operates at Layer 2, forwarding frames based on MAC addresses while connecting different physical media (e.g., copper to fiber). It does not perform routing, making it the correct choice for this scenario. Unlike a media converter, a bridge also provides segmentation and collision domain isolation.

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Layer 3 switch

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Media converter

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Router

Question 15

A company is implementing a wireless network and needs to support high-density client environments with minimal interference. Which IEEE 802.11 standard operates in the 5 GHz band and provides the highest throughput among the options?

Accepted Answer

802.11ac. 802.11ac (Wi-Fi 5) operates exclusively in the 5 GHz band and supports up to 8 spatial streams, 256-QAM modulation, and channel bonding up to 160 MHz, yielding theoretical throughput exceeding 6.9 Gbps. This makes it the highest-throughput option among the listed standards for high-density environments with minimal interference, as the 5 GHz band offers more non-overlapping channels and less co-channel contention than 2.4 GHz.

Answer

802.11n

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802.11g

Answer

802.11b