N10-009 Practice Test 28 — 15 Questions

Question 1

A network administrator needs to monitor network devices using SNMP. The security policy requires that both authentication and data encryption must be enforced for all SNMP operations. Which SNMPv3 security level should be configured?

Accepted Answer

authPriv. The authPriv security level is correct because it enforces both authentication (via HMAC-MD5 or HMAC-SHA) and data encryption (via DES or AES) for SNMPv3 operations, satisfying the security policy requirement. SNMPv3 defines three security levels: noAuthNoPriv, authNoPriv, and authPriv, with authPriv being the only one that provides both authentication and encryption.

Answer

noAuthNoPriv

Answer

authNoPriv

Answer

noAuthPriv

Question 2

A network monitoring system alerts that a specific router interface has been flapping (repeatedly going up and down) for the past hour. Which of the following is the MOST likely cause of this behavior?

Accepted Answer

Faulty transceiver. A faulty transceiver is the most likely cause of interface flapping because physical-layer issues, such as a failing SFP or GBIC, can cause intermittent loss of signal or link synchronization. The router's interface detects the loss of carrier and brings the link down, then re-establishes it when the signal returns, creating a repeated up/down cycle. This is a common hardware failure mode distinct from software or configuration problems.

Answer

High CPU utilization on the router

Answer

Incorrect SNMP community string

Answer

Routing protocol misconfiguration

Question 3

A network administrator wants to collect performance data from network devices over time and receive alerts when thresholds are exceeded. Which protocol should be used?

Accepted Answer

SNMP. SNMP (Simple Network Management Protocol) is designed to collect performance data from network devices by polling MIB (Management Information Base) objects and can generate traps or inform requests to send alerts when thresholds are exceeded. This makes it the correct choice for proactive monitoring and threshold-based alerting.

Answer

syslog

Answer

NetFlow

Answer

ICMP

Question 4

A network administrator needs to connect two switches to allow multiple VLANs to traverse the link. Which protocol should be used to tag frames with VLAN information?

Accepted Answer

802.1Q. 802.1Q is the IEEE standard for VLAN tagging, which inserts a 4-byte tag into the Ethernet frame header to identify the VLAN membership of the frame. This allows multiple VLANs to traverse a single trunk link between switches, enabling inter-switch VLAN communication without requiring separate physical links per VLAN.

Answer

STP (Spanning Tree Protocol)

Answer

VTP (VLAN Trunking Protocol)

Answer

LACP (Link Aggregation Control Protocol)

Question 5

A network engineer is designing a wireless network for a large warehouse with many metal racks and heavy machinery that cause significant RF interference. The network must support a high density of IoT sensors and provide reliable connectivity. Which IEEE wireless standard should the engineer implement to best meet these requirements?

Accepted Answer

802.11ax (Wi-Fi 6). 802.11ax (Wi-Fi 6) is the correct choice because it introduces Orthogonal Frequency Division Multiple Access (OFDMA), which subdivides channels into smaller resource units (RUs) to serve multiple IoT sensors simultaneously, improving efficiency in dense, interference-heavy environments. Additionally, Wi-Fi 6 includes BSS Coloring, which reduces co-channel interference by allowing devices to ignore transmissions from overlapping basic service sets, and Target Wake Time (TWT), which schedules IoT sensor transmissions to conserve battery and reduce contention.

Answer

802.11ac (Wi-Fi 5)

Answer

802.11n (Wi-Fi 4)

Answer

802.11g (Wi-Fi 3)

Question 6

A network administrator wants to monitor network devices using SNMP. The security policy requires both authentication and encryption of SNMP packets. Which SNMP version and security level should be configured?

Accepted Answer

SNMPv3 with authPriv. SNMPv3 is the only version that supports both authentication and encryption. The security level 'authPriv' enables both authentication (via HMAC-MD5 or HMAC-SHA) and encryption (via CBC-DES or CFB128-AES), meeting the policy requirement. SNMPv1 and SNMPv2c use only plaintext community strings with no security, while 'authNoPriv' provides authentication without encryption.

Answer

SNMPv2c with a community string

Answer

SNMPv3 with authNoPriv

Answer

SNMPv1 with a community string

Question 7

A network administrator needs to maintain a record of all configuration changes made to network switches, including the date, time, and the administrator who made the change. Which document should be used for this purpose?

Accepted Answer

Change management log. A change management log is the correct document because it is specifically designed to record configuration changes, including the date, time, and the administrator responsible. This log provides an audit trail for network devices, ensuring compliance and facilitating troubleshooting by tracking who made what change and when.

Answer

Network topology diagram

Answer

Baseline configuration report

Answer

Incident report

Question 8

A network administrator wants to centrally monitor the status of all network devices and receive alerts when an interface goes down. Which protocol and feature combination should the administrator use?

Accepted Answer

SNMP with traps. SNMP traps provide unsolicited, asynchronous notifications from network devices to the management station when specific events occur, such as an interface going down. This allows the administrator to receive immediate alerts without continuously polling each device, making it the ideal protocol and feature combination for real-time status monitoring and alerting.

Answer

SNMP with polling

Answer

Syslog with severity levels

Answer

NetFlow with flow logs

Question 9

A network engineer is explaining to a manager why wireless networks often have lower throughput than wired Ethernet. Which of the following best describes the primary reason for this difference?

Accepted Answer

Wireless uses CSMA/CA which involves a collision avoidance mechanism that adds overhead, whereas wired Ethernet uses CSMA/CD which only responds after collision.. Option C is correct because wireless networks use CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance), which requires stations to perform a four-way handshake (RTS/CTS) and wait for an acknowledgment before transmitting. This collision avoidance mechanism introduces significant overhead, reducing effective throughput. In contrast, wired Ethernet uses CSMA/CD, which detects collisions after they occur and does not require such proactive overhead, allowing higher throughput.

Answer

Wireless uses a different MAC method that requires waiting for an acknowledgment, reducing available bandwidth.

Answer

Wireless operates at half-duplex, while wired Ethernet typically operates at full-duplex.

Answer

Wireless signals are subject to interference, but the MAC protocol is identical to Ethernet.

Question 10

A network administrator wants to ensure that SNMP traffic between the network monitoring server and managed devices is encrypted and provides authentication of the data origin. Which version of SNMP should be implemented?

Accepted Answer

C: SNMPv3. SNMPv3 is the correct choice because it provides both encryption (via the AuthPriv security level) and data origin authentication (via the AuthNoPriv or AuthPriv levels). Unlike earlier versions, SNMPv3 includes a security model that ensures confidentiality, integrity, and authentication, meeting the administrator's requirements.

Answer

A: SNMPv1

Answer

B: SNMPv2c

Answer

D: SNMPv2

Question 11

A network architect is designing a Software-Defined Networking (SDN) based network. Which of the following components is responsible for making centralized forwarding decisions and communicating those decisions to the physical switches using southbound APIs?

Accepted Answer

Control layer. In SDN architecture, the control layer (also known as the SDN controller) is the centralized entity responsible for making all forwarding decisions. It communicates these decisions to the physical switches via southbound APIs, such as OpenFlow, which program the flow tables in the data plane. This separation of the control plane from the data plane is the fundamental principle of SDN.

Answer

Application layer

Answer

Data plane

Answer

East-west interfaces

Question 12

A network engineer wants to segment a LAN into multiple broadcast domains without purchasing additional hardware. Which of the following technologies should be implemented?

Accepted Answer

VLANs. VLANs (Virtual Local Area Networks) allow a network engineer to logically segment a single physical LAN switch into multiple isolated broadcast domains without purchasing additional hardware. By assigning switch ports to different VLAN IDs, broadcast traffic is confined to ports within the same VLAN, effectively creating separate Layer 2 networks on the same switch infrastructure.

Answer

Subnetting

Answer

VPN

Answer

NAT

Question 13

Which of the following best describes the primary difference between a hub and a switch?

Accepted Answer

A hub broadcasts all frames to all ports; a switch forwards frames only to the destination port. A hub operates at Layer 1 (physical layer) and simply repeats electrical signals out all ports, causing all connected devices to receive every frame. A switch operates at Layer 2 (data link layer) and uses the MAC address table to forward frames only to the specific port where the destination device resides, reducing unnecessary traffic and improving network efficiency.

Answer

A switch is faster than a hub because it operates at Layer 3

Answer

A hub can segment collision domains; a switch cannot

Answer

Both hubs and switches operate at the same OSI layer but use different frame types

Question 14

A network engineer needs to install 15 wireless access points that each require 25W of power. The available switch provides PoE+ (802.3at) with a total power budget of 740W. The engineer also needs to connect 10 IP cameras that each require 12W. Which of the following should the engineer verify before proceeding with the installation?

Accepted Answer

The total power consumption of all devices does not exceed the switch's power budget.. The total power required is 15 APs × 25W + 10 cameras × 12W = 375W + 120W = 495W, which is well below the switch's 740W PoE+ budget. However, the engineer must verify that the cumulative power draw does not exceed the budget, as exceeding it would cause some ports to be denied power or shut down. This is the fundamental prerequisite for any PoE deployment.

Answer

The switch supports LLDP-MED for power negotiation.

Answer

All PoE devices are from the same manufacturer.

Answer

The cable length does not exceed 150 meters.

Question 15

A network engineer is designing a subnet for a department that requires exactly 50 usable host addresses. Which subnet mask provides the minimum number of usable host addresses while still accommodating the requirement?

Accepted Answer

/26. A /26 subnet mask (255.255.255.192) provides 2^(32-26) = 64 total addresses, of which 62 are usable (subtracting network and broadcast addresses). This is the smallest subnet that meets the requirement of exactly 50 usable hosts, as /27 yields only 30 usable addresses and /28 yields only 14, while /25 provides 126 usable addresses, which is more than necessary.

Answer

/27

Answer

/28

Answer

/25