100-150 Practice Test 23 — 15 Questions

Question 1

While testing a new 100-meter copper cable run, the technician notices that the signal is very weak at the far end, resulting in intermittent drops. What is the most likely cause of this signal weakening?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

Attenuation. Attenuation is the weakening of a signal as it travels over distance through a medium. In copper cables, signal loss increases with length and frequency, so a 100-meter run may experience significant attenuation, causing weak signal and intermittent drops. This is the most likely cause of the described symptom.

Answer

Crosstalk

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Dispersion

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Refraction

Question 2

Which of the following scenarios best demonstrates the function of the Network layer in the OSI model?

Accepted Answer

A router determining the best path to reach a remote subnet.. The Network layer is responsible for logical addressing and routing. When data must travel between different networks, the Network layer determines the optimal path using routing protocols and IP addressing. This is critical for global network connectivity, as it allows packets to traverse multiple routers and hop between disparate subnetworks to reach their final destination across the internet or enterprise infrastructure.

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A switch forwarding a frame based on a destination MAC address.

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A client establishing a TCP three-way handshake with a server.

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A browser displaying an HTML page retrieved from a web server.

Question 3

A network administrator is setting up a small office network with a single Cisco router and multiple switches. The administrator wants to ensure that devices on different VLANs can communicate with each other. Which feature should be configured on the router?

Accepted Answer

Router-on-a-stick with subinterfaces. Router-on-a-stick is a technique that uses a single physical router interface with multiple subinterfaces, each configured for a different VLAN. The router then routes traffic between these subinterfaces, enabling inter-VLAN communication. This is an efficient and common solution for small networks where multiple physical router interfaces are not available.

Answer

Spanning Tree Protocol on the router

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Port mirroring on the switch

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Dynamic ARP Inspection on the switch

Question 4

A network administrator is troubleshooting a connectivity issue between two hosts on the same VLAN. The administrator uses the 'show mac address-table' command on the switch and notices that the MAC address of one host appears on multiple ports. What is the most likely cause of this behavior?

Accepted Answer

A switching loop exists in the network.. A MAC address appearing on multiple ports is a strong indicator of a switching loop. In a loop, broadcast and unknown unicast frames are flooded endlessly, and the switch learns the source MAC address from different ports as frames traverse the loop in both directions. This causes MAC address flapping, which can destabilize the network.

Answer

Port security is misconfigured and allowing the MAC address on multiple ports.

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The switch's CAM table is corrupted and needs to be cleared.

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The host is connected to multiple switch ports via a dual-homed NIC.

Question 5

A help desk technician receives a call from an employee who says they received a text message claiming to be from the bank's fraud department, asking them to click a link and confirm their online banking password. The employee has not clicked the link. Which type of attack is this?

Accepted Answer

Smishing. The message arrived as an SMS text impersonating a bank, which is the defining characteristic of smishing. Vishing requires a voice call, whaling targets executives, and pharming relies on DNS or hosts file manipulation rather than a text lure. Recognizing the delivery channel is the key to correctly classifying the social engineering attack.

Answer

Pharming

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Whaling

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Vishing

Question 6

A help desk technician is troubleshooting a Windows workstation that cannot reach any resources on the local subnet. The technician runs ipconfig /all and notices the workstation has an IP address of 192.168.1.50 with a subnet mask of 255.255.255.0, but the default gateway field is blank. The workstation can ping other hosts on the same subnet. What is the most likely cause of the inability to reach remote networks?

Accepted Answer

The default gateway is missing, so the workstation cannot forward traffic to remote networks.. The workstation can ping local hosts, so the local IP and subnet mask are functional. The missing default gateway means the host has no route for destinations outside its own subnet. Without a gateway, packets for remote networks are dropped, which explains why only local communication works. Assigning the correct gateway address restores remote connectivity.

Answer

The DNS server address is not configured, preventing name resolution for remote hosts.

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The workstation is configured with an APIPA address and cannot communicate off-subnet.

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The workstation has an incorrect subnet mask, preventing it from identifying remote networks.

Question 7

A network technician is tasked with connecting two distribution switches located in separate buildings 500 meters apart. Which media type should be selected to ensure reliable connectivity and high bandwidth without the need for repeaters?

Accepted Answer

Single-mode fiber optic cabling. Optical fiber provides the necessary distance capabilities for a 500-meter run, which significantly exceeds the 100-meter limit of standard copper UTP cabling. In an industrial or outdoor environment, fiber is also immune to electromagnetic interference from heavy machinery or power lines. Understanding media limitations ensures that network technicians select the appropriate physical layer components to maintain signal integrity.

Answer

Category 6 UTP cabling

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Shielded Twisted Pair (STP) cabling

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Category 5e crossover cabling

Question 8

A small office wants to keep its wireless network traffic private so that neighbors cannot read the data being transmitted. Which technology should be enabled on the wireless access point to encrypt traffic between clients and the access point?

Accepted Answer

WPA2 with AES. Enabling WPA2 with AES on the access point encrypts the wireless frames so that only authorized clients with the correct pre-shared key or credentials can decrypt them. Neighbors capturing the radio signal see only ciphertext. The other listed measures either hide information or filter clients but leave the actual data readable.

Answer

DHCP snooping

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MAC address filtering

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SSID broadcast disabled

Question 9

In a high-density data center, a technician needs to connect a server to a fiber patch panel using a small form factor connector that supports a push-pull locking mechanism. Which connector should be used?

Accepted Answer

LC (Lucent Connector). Connector types are a vital part of media selection in modern networking. Small form factor connectors allow for higher port density on networking equipment. Choosing the correct connector ensures physical compatibility with transceivers and patch panels while providing the mechanical security needed for high-availability data center environments.

Answer

ST (Straight Tip)

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SC (Subscriber Connector)

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RJ-45

Question 10

Which of the following best describes the benefit of implementing a hierarchical network design model?

Accepted Answer

It simplifies network management and promotes scalability.. Hierarchical designs, such as the Cisco Core-Distribution-Access model, improve scalability, performance, and manageability. By separating functions into layers, administrators can apply policies and scale specific parts of the network without impacting the entire infrastructure. This modularity is essential for modern enterprise networks that require high availability and consistent performance across thousands of connected devices and diverse geographic locations.

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It eliminates the need for routing protocols.

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It forces all traffic to be processed by a single core router.

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It ensures that all devices operate at the same speed.

Question 11

Which THREE statements accurately describe the functions of a Layer 2 switch in a local area network?

Accepted Answer

Switches use MAC addresses to make forwarding decisions.. Layer 2 switches are the workhorses of local networks, providing high-speed connectivity by managing frame delivery. Unlike hubs, switches use hardware-based logic to segment the network and optimize traffic flow. Understanding how they build address tables and handle different types of traffic is essential for any technician responsible for maintaining or troubleshooting enterprise network infrastructure and ensuring data reaches its intended destination.

Answer

Switches route traffic between different VLANs using IP addresses.

Answer

Switches perform deep packet inspection to filter malicious traffic.

Question 12

As data moves down the OSI model from the Application layer to the Physical layer, what is the process called where each layer adds its own control information?

Accepted Answer

Encapsulation. Encapsulation is the fundamental process of wrapping data in a protocol header at each layer of the OSI model. This allows each layer to provide specific services, such as error checking or routing, without needing to understand the contents of the layers above it. It ensures that data is properly formatted for transmission across the network.

Answer

De-encapsulation

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Segmentation

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Modulation

Question 13

An administrator needs to subnet the 192.168.10.0/24 network into subnets that support at least 25 hosts each. Which CIDR mask provides the most efficient use of addresses while meeting the requirement?

Accepted Answer

/27. To support 25 hosts, the subnetwork must provide at least 27 usable IP addresses, accounting for network and broadcast IDs. The formula 2^n - 2 >= 25 indicates n=5 host bits are required, leaving 27 bits for the network portion. Using a /27 mask results in 30 usable hosts per subnet, which is the most efficient configuration compared to larger allocations that would waste addresses.

Answer

/25

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/26

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/28

Question 14

Which TWO of the following are primary benefits of using G.729 audio codec for voice traffic in bandwidth-constrained environments? (Choose two)

Accepted Answer

It significantly reduces the required bandwidth per voice call.. G.729 is a highly efficient compression algorithm designed to minimize bandwidth usage for voice communication. By reducing the payload size significantly compared to G.711, it allows more concurrent calls over limited WAN links. Recognizing codec efficiency is essential for network engineers, as improper codec selection can lead to link saturation, dropping packets, and severely degrading user experience during peak business hours.

Answer

It provides the highest possible audio fidelity for high-end telepresence.

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It is natively supported by every legacy analog endpoint without an adapter.

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It lowers the processing overhead on the gateway's DSP hardware.

Question 15

A network engineer is analyzing a packet capture and observes a TCP segment with the SYN flag set and the ACK flag not set. The engineer needs to determine the purpose of this segment in the TCP three-way handshake. What is the purpose of this TCP segment?

Accepted Answer

It is the first step in the three-way handshake, requesting to establish a connection.. A TCP segment with the SYN flag set and ACK flag not set is the initial SYN segment in the three-way handshake. It is sent by the client to initiate a connection and synchronize sequence numbers. The server responds with SYN-ACK, and the client sends an ACK to complete the handshake. This segment is not used for acknowledgment, completion, or termination.

Answer

It is the second step in the three-way handshake, acknowledging the request and synchronizing sequence numbers.

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It is the third step in the three-way handshake, completing the connection establishment.

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It is a segment used to terminate an existing TCP connection.