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Question 21

What does a switch do when receiving an unknown frame?

1. Drops the frame immediately without forwarding.
2. Floods the frame out all ports except the receiving port.
3. Sends an error message back to the source device.
4. Stores the frame in nvram for future analysis.

Correct Answer: 2

Explanation:

When a Layer 2 switch receives an incoming Ethernet frame with a destination MAC address that does not currently exist within its Content Addressable Memory table, it executes a process known as unknown unicast flooding. The switch floods the frame out of all active ports belonging to the same VLAN, excluding the port on which the frame was originally received. This ensures that the target device, regardless of its port location, receives the transmission. Once the destination device responds, the switch records the source MAC address and associated port in its table to prevent future flooding for that specific address pair.

Question 22

Which protocol dynamically resolves IP addresses to MAC addresses?

1. Domain Name System.
2. Address Resolution Protocol.
3. Dynamic Host Configuration Protocol.
4. Simple Network Management Protocol.

Correct Answer: 2

Explanation:

The Address Resolution Protocol is an essential networking protocol operating within the Internet Protocol suite used to map logical Layer 3 IPv4 addresses to physical Layer 2 MAC addresses. When a host needs to transmit data across a local area network segment, it knows the destination IP address but requires the corresponding hardware MAC address to build a valid Ethernet frame header. The sending device broadcasts an ARP request packet containing the target IP address. The node assigned that IP address responds with its unique hardware MAC address, allowing the sender to cache the mapping and complete frame encapsulation successfully.

Question 23

What is the primary function of an edge router?

1. Connecting an enterprise local network to an external wide area network.
2. Providing high-speed switching between internal department workstations.
3. Translating domain names into numerical IP addresses.
4. Managing printer queues and file shares across the campus.

Correct Answer: 1

Explanation:

An edge router, often referred to as a boundary router, is positioned at the perimeter of an enterprise network to connect local area network infrastructure to external wide area networks or Internet Service Provider connections. It handles critical tasks such as external routing protocol exchanges, public-to-private Network Address Translation, border security policy enforcement, and VPN tunnel termination. By serving as the gateway between internal private networks and the public internet, the edge router manages external traffic flow, enforces perimeter security, and protects internal assets from unauthorized external access threats.

Question 24

Which command displays the IP routing table on Cisco routers?

1. show running-config
2. show ip route
3. show interfaces brief
4. show ip arp

Correct Answer: 2

Explanation:

The show ip route command is one of the most frequently utilized diagnostic commands within the Cisco IOS command-line interface. When executed in privileged EXEC mode, it displays the router’s current active IP routing table. This output details directly connected networks, static routes, and dynamically learned routes via protocols like OSPF or EIGRP. Network engineers examine this table to verify route metrics, next-hop IP addresses, exit interfaces, and administrative distances, making it an indispensable tool for troubleshooting reachability issues, validating routing protocol convergence, and verifying network path selection.

Question 25

What is the maximum segment length for standard UTP cabling?

1. 50 meters
2. 100 meters
3. 185 meters
4. 500 meters

Correct Answer: 2

Explanation:

According to ANSI/TIA and ISO/IEC cabling standards, the maximum allowable length for a horizontal unshielded twisted pair or shielded twisted pair copper cable run in an Ethernet network is 100 meters. This specific limit comprises a maximum of 90 meters of permanent solid-core link cable installed within building walls or cable trays, combined with a maximum of 10 meters of stranded patch cables utilized at the telecommunications closet and workstation ends. Exceeding this 100-meter threshold introduces excessive signal attenuation, propagation delay, and jitter, leading to high bit error rates and dropped packets across the connection.

Question 26

Which IPv6 address scope is limited to the local link?

1. Global Unicast Address
2. Unique Local Address
3. Link-Local Address
4. Multicast Address

Correct Answer: 3

Explanation:

An IPv6 Link-Local Address is automatically configured on every IPv6-enabled interface as soon as the protocol is initialized, utilizing the reserved prefix fe80::/10. Link-local addresses are strictly non-routable, meaning routers will never forward packets containing link-local source or destination addresses outside the local network segment. These addresses are essential for fundamental neighbor discovery, router solicitation, and basic local communication between neighboring nodes on the exact same physical or logical link before global or unique local addressing is established.

Question 27

What type of route has an administrative distance of one?

1. Directly connected route
2. Static route
3. OSPF dynamic route
4. EIGRP dynamic route

Correct Answer: 2

Explanation:

Administrative distance represents the trustworthiness or preference level of a routing information source, where lower values indicate higher reliability. In Cisco IOS routing architecture, a manually configured static route is assigned a default administrative distance of one, making it highly preferred over any dynamic routing protocol unless modified by an administrator. Directly connected routes hold an administrative distance of zero. Because static routes have an administrative distance of one, they will override dynamically learned routes to the same destination network unless overridden by floating static routes with higher administrative distance values.

Question 28

Which device operates at the physical layer of the OSI model?

1. Layer 2 Switch
2. Router
3. Network Hub
4. Multilayer Switch

Correct Answer: 3

Explanation:

A traditional network hub operates strictly at Layer 1, the physical layer of the OSI reference model. When a hub receives electrical or optical signals on one of its ports, it simply regenerates that signal and broadcasts it out all other active ports without examining header information, MAC addresses, or packet contents. Because hubs do not filter traffic or establish separate collision domains, all connected devices share a single collision domain and a single broadcast domain, leading to increased contention and potential performance degradation in busy network environments.

Question 29

What is the primary purpose of subnetting an IPv4 network?

1. Increasing available bandwidth on physical fiber optic links.
2. Dividing a single large network into smaller, manageable sub-networks.
3. Encrypting payload data against unauthorized third-party interception.
4. Converting private internal IP addresses into public routable addresses.

Correct Answer: 2

Explanation:

Subnetting is the strategic practice of dividing a single large physical IP network into multiple smaller, logically distinct sub-networks. By borrowing bits from the host portion of an IPv4 address and reallocating them to the network mask, network administrators reduce broadcast domain size, improve overall network performance, enhance security isolation between departments, and conserve scarce IPv4 address space. Subnetting enables efficient routing table summarization and structured organizational planning across complex enterprise network topologies.

Question 30

Which protocol provides secure remote command-line access to network devices?

1. Telnet
2. HTTP
3. Secure Shell
4. Simple Network Management Protocol

Correct Answer: 3

Explanation:

Secure Shell is a cryptographic network protocol designed for operating network services securely over an unsecured network. In enterprise networking environments, SSH is used as a secure replacement for legacy Telnet sessions when administrators remotely log into routers, switches, and firewalls to execute command line configurations. Unlike Telnet, which transmits all authentication credentials, usernames, passwords, and command keystrokes in plain text across the network where they can be easily intercepted, SSH encrypts all transmitted data streams to prevent unauthorized eavesdropping.

Question 31

What field in the IPv4 header prevents infinite routing loops?

1. Total Length
2. Time to Live
3. Protocol Identifier
4. Header Checksum

Correct Answer: 2

Explanation:

The Time to Live field in the IPv4 header is an 8-bit integer designed to prevent packets from circulating indefinitely inside a misconfigured routing loop. Every router that processes and forwards the packet decrements the TTL value by one. If the TTL counter reaches zero before the packet arrives at its final destination, the router drops the packet and generates an Internet Control Message Protocol Time Exceeded error message back to the original source host. This mechanism protects network bandwidth from exhaustion caused by routing loops.

Question 32

Which switching method checks the destination MAC address before forwarding?

1. Cut-through switching
2. Fragment-free switching
3. Store-and-forward switching
4. Direct-access switching

Correct Answer: 3

Explanation:

In store-and-forward switching, the switch receives the entire Ethernet frame into its internal memory buffer before taking any forwarding action. Once the complete frame is received, the switch performs a Cyclic Redundancy Check to verify frame integrity, checking for mathematical errors and runt frames. Only if the frame passes validation does the switch examine the destination MAC address, look up the forwarding table, and forward the frame out the appropriate egress port. This method ensures error-free transmission but introduces slightly higher latency than cut-through methods.

Question 33

What protocol is used to test network connectivity between hosts?

1. Address Resolution Protocol
2. Internet Control Message Protocol
3. Dynamic Host Configuration Protocol
4. Transmission Control Protocol

Correct Answer: 2

Explanation:

The Internet Control Message Protocol is a core auxiliary protocol utilized within the Internet Protocol suite for diagnostic, error reporting, and operational testing purposes. Network engineers and automated systems rely on ICMP echo request and echo reply messages, commonly executed via the ping command, to test end-to-end network connectivity, measure round-trip transmission latency, and verify host reachability. Additionally, ICMP generates essential administrative notification messages, such as destination unreachable and time exceeded alerts, when routing or packet delivery failures occur.

Question 34

Which cable type combines multiple fibers surrounded by protective cladding?

1. Unshielded Twisted Pair
2. Shielded Twisted Pair
3. Coaxial Cable
4. Fiber Optic Cable

Correct Answer: 4

Explanation:

A fiber optic cable consists of one or more extremely thin strands of glass or plastic fiber encased in protective cladding and outer jackets. Data is transmitted across fiber optic cables as pulses of light generated by lasers or light-emitting diodes. Because optical transmission relies on light rather than electrical current, fiber optic cables are entirely immune to electromagnetic interference and radio frequency interference. They support significantly higher bandwidth capacities and much longer transmission distance limitations compared to traditional copper-based cabling media.

Question 35

What is the default administrative distance of a static route?

1. 0
2. 1
3. 90
4. 110

Correct Answer: 2

Explanation:

Administrative distance is the metric Cisco routers use to select the best path when two or more different routing protocols learn a route to the same destination network. Lower administrative distance values indicate higher trustworthiness. A static route configured manually by an administrator carries a default administrative distance of one, making it highly preferred over dynamic routing protocols. Directly connected interfaces have an administrative distance of zero. Understanding these default values is crucial for network design, backup route implementation, and traffic engineering.

Question 36

Which layer of the OSI model handles data encryption and formatting?

1. Physical Layer
2. Data Link Layer
3. Presentation Layer
4. Application Layer

Correct Answer: 3

Explanation:

The Presentation layer, which is Layer 6 of the OSI reference model, is responsible for ensuring that data sent from the application layer of one system can be read and interpreted by the application layer of another system. This layer handles data formatting, syntax translation, character set conversion, data compression, and cryptographic encryption or decryption services. By standardizing data representation formats, the presentation layer abstracts underlying operating system differences and ensures secure, compatible data exchanges across heterogeneous network environments.

Question 37

What is the primary purpose of VLAN trunking protocols?

1. Encrypting wireless data frames against unauthorized eavesdropping.
2. Carrying traffic for multiple VLANs across a single physical link.
3. Automatically assigning IP addresses to client workstations.
4. Translating private internal IP addresses into public addresses.

Correct Answer: 2

Explanation:

A VLAN trunk link is a specialized physical connection between switches or between a switch and a router configured to carry traffic belonging to multiple Virtual Local Area Networks simultaneously. To distinguish which frame belongs to which VLAN as traffic traverses the shared link, switches insert a VLAN identifier tag into the Ethernet frame header according to IEEE 802.1Q standards. Trunking eliminates the requirement of dedicating a separate physical switch port and cable for every single VLAN, maximizing port density and scalability.

Question 38

Which IPv4 address range is designated for private network use?

1. 8.8.8.0 through 8.8.8.255
2. 192.168.0.0 through 192.168.255.255
3. 172.32.0.0 through 172.63.255.255
4. 10.256.0.0 through 10.256.255.255

Correct Answer: 2

Explanation:

In accordance with Internet Engineering Task Force standards defined in RFC 1918, specific blocks of IPv4 address space are reserved for private internal use within organizational local area networks and are not routable across the public internet. These designated private ranges include 10.0.0.0 through 10.255.255.255, 172.16.0.0 through 172.31.255.255, and 192.168.0.0 through 192.168.255.255. Organizations utilize Network Address Translation gateways to translate these private internal source addresses into registered public IP addresses when communicating with external internet resources.

Question 39

What protocol automates IP address assignment on enterprise networks?

1. Domain Name System
2. Dynamic Host Configuration Protocol
3. Address Resolution Protocol
4. File Transfer Protocol

Correct Answer: 2

Explanation:

The Dynamic Host Configuration Protocol is a network management protocol used to automate the configuration of client devices connected to an IP network. Instead of manually assigning static IP addresses, subnet masks, default gateways, and DNS server addresses to every individual workstation, a DHCP server leases these configuration parameters dynamically from a predefined address pool. This eliminates manual configuration errors, optimizes IP address utilization through temporary lease expirations, and simplifies network administration across enterprise environments.

Question 40

Which networking device creates separate collision domains for each port?

1. Network Hub
2. Layer 2 Switch
3. Passive Patch Panel
4. Coaxial Repeater

Correct Answer: 2

Explanation:

A Layer 2 switch isolates collision domains by treating every individual switch port as an independent collision domain segment. Unlike legacy hubs where all connected devices share a single collision domain and contend for media access, a switch buffers frames and manages transmission access per port. This architectural advantage allows full-duplex communication where devices can transmit and receive data simultaneously without experiencing frame collisions, resulting in drastically improved network performance and throughput capacity across the local infrastructure.