View Full Cisco 100-150 Exam Dumps and Practice Test Dumps.

 

Question 181

What is the primary function of the Data Link layer of the OSI model?

1. Providing reliable end-to-end transport layer delivery across networks.
2. Managing physical media transmission using electrical and optical signals.
3. Providing node-to-node data transfer and physical addressing error detection.
4. Routing packets across disparate wide area network boundaries.

Correct Answer: 3

Explanation:

The Data Link layer, which is Layer 2 of the OSI reference model, is responsible for reliable node-to-node data transfer across a physical network segment. It encapsulates raw bits from the physical layer into logical frames, appends physical MAC addressing headers, and implements error detection mechanisms like the Frame Check Sequence trailer. By managing media access control and detecting transmission errors across local connections, the data link layer ensures clean frame delivery between adjacent network nodes before upper layers process the data.

Question 182

Which command verifies the operational status of all interfaces on a Cisco device?

1. show running-config
2. show ip interface brief
3. show ip route
4. show version

Correct Answer: 2

Explanation:

The show ip interface brief command is one of the most frequently utilized diagnostic commands within the Cisco IOS command-line interface. When executed, it generates a concise summary table displaying all physical and logical interfaces on the device, their assigned IPv4 addresses, physical layer operational status, and data link protocol states. Network engineers rely on this command during initial deployments and troubleshooting procedures to verify whether ports are up or down, confirm IP address configurations, and rapidly identify interface failures or misconfigurations across routers and switches.

Question 183

What protocol resolves human-readable domain names into numerical IP addresses?

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

Correct Answer: 3

Explanation:

The Domain Name System is a hierarchical and decentralized naming system used to translate human-readable fully qualified domain names into numerical IPv4 or IPv6 addresses required for network routing and host identification. Because remembering complex numerical IP addresses is impractical for human users, DNS servers map user-friendly names to their corresponding network addresses automatically. When a user enters a web address or application hostname into a system, a DNS query is dispatched to resolve the name into an actionable IP address, facilitating seamless communication across local area networks and the global internet infrastructure without manual intervention.

Question 184

Which IEEE standard governs wired Ethernet local area networks?

1. IEEE 802.11
2. IEEE 802.1Q
3. IEEE 802.1X
4. IEEE 802.3

Correct Answer: 4

Explanation:

The IEEE 802.3 standard family defines the physical layer and media access control specifications for wired Ethernet local area networks. Over decades of technological evolution, 802.3 has expanded from early coaxial implementations to encompass twisted pair copper cabling standards such as 10BASE-T, 100BASE-TX, and 1000BASE-T, as well as various optical fiber standards. In contrast, IEEE 802.11 governs wireless local area networks, IEEE 802.1Q specifies Virtual Local Area Network tagging on Ethernet frames, and IEEE 802.1X provides port-based network access control authentication mechanisms.

Question 185

What is the default subnet mask for a Class B IPv4 network?

1. 255.0.0.0
2. 255.255.0.0
3. 255.255.255.0
4. 255.255.255.255

Correct Answer: 2

Explanation:

In traditional classful IPv4 addressing, Class B networks are designated for medium to large-scale enterprise networks and utilize a default subnet mask of 255.255.0.0. In binary representation, this corresponds to sixteen network bits followed by sixteen host bits. This mask indicates that the first two octets of the IP address identify the specific network segment, while the final two octets are available for host device identification. This configuration allows a maximum of 65,534 usable host IP addresses per network segment after reserving the network identifier and broadcast addresses.

Question 186

Which switching method stores the entire frame and checks the FCS 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 by analyzing the Frame Check Sequence trailer to verify frame integrity, checking for mathematical errors, corrupted bits, 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, ensuring error-free transmission across the network.

Question 187

What protocol assigns dynamic IP configuration parameters to client hosts?

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

Correct Answer: 1

Explanation:

The Dynamic Host Configuration Protocol is a network management protocol used to automate the configuration of 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, allowing seamless client onboarding and mobility.

Question 188

Which routing protocol uses a hop count metric with a maximum limit of 15 hops?

1. Open Shortest Path First
2. Enhanced Interior Gateway Routing Protocol
3. Routing Information Protocol
4. Border Gateway Protocol

Correct Answer: 3

Explanation:

The Routing Information Protocol is a classic distance-vector routing protocol that utilizes a simple hop count metric to determine the best path to a destination network. Every router a packet must traverse along a given path counts as a single hop, with a metric value incrementing by one for each router crossed. RIP enforces a strict maximum hop count limit of fifteen hops to prevent infinite routing loops, meaning any destination requiring sixteen or more hops is considered completely unreachable. While easy to configure, this reliance solely on hop count limits RIP scalability in large network topologies.

Question 189

What type of IPv6 address is fe80::/10?

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

Correct Answer: 4

Explanation:

An IPv6 Link-Local Address is automatically configured on all IPv6-enabled interfaces 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, ensuring local connectivity.

Question 190

Which TCP flag initiates a connection during the three-way handshake?

1. ACK
2. FIN
3. SYN
4. RST

Correct Answer: 3

Explanation:

The Synchronize flag is utilized during the initial phase of the Transmission Control Protocol three-way handshake to establish a reliable connection between two network hosts. The connection sequence begins when the client sends a segment containing the SYN flag and an initial sequence number to the server. The server responds with a SYN-ACK segment acknowledging the request and providing its own sequence number. Finally, the client replies with an ACK packet, confirming receipt and completing the handshake so data transmission can commence securely.

Question 191

What is the primary function of a default gateway?

1. Encrypting payload data across insecure wireless links.
2. Forwarding packets destined for remote networks outside the local segment.
3. Dynamically assigning configuration parameters to client workstations.
4. Translating private internal IP addresses into public addresses.

Correct Answer: 2

Explanation:

The default gateway is a critical routing device, typically a router or multilayer switch, configured on a host to handle outbound traffic destined for networks outside the local subnet. When an end device needs to communicate with an IP address that resides on a different logical network, it cannot deliver the packet directly using Layer 2 MAC addresses. Instead, the host encapsulates the packet inside an Ethernet frame addressed to the hardware MAC address of the default gateway. The gateway receives the packet, strips the Layer 2 header, evaluates the Layer 3 destination IP address against its routing table, and forwards the packet toward its ultimate destination across wide area links or enterprise core routers.

Question 192

Which command displays the active configuration currently stored in RAM?

1. show startup-config
2. show running-config
3. show version
4. show flash

Correct Answer: 2

Explanation:

The show running-config command is an essential diagnostic and verification command executed in privileged EXEC mode within the Cisco IOS command-line interface. It displays the complete configuration file currently residing in the device’s random-access memory, representing all active parameters, interface assignments, routing protocols, access control lists, and security settings currently governing device operations. Network engineers examine the running configuration to verify recent changes before saving them to non-volatile random-access memory using the write memory or copy running-config startup-config commands.

Question 193

What protocol resolves logical IPv4 addresses to physical MAC addresses?

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

Correct Answer: 3

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 communicate with another device on the same local network segment, it knows the destination IP address but requires the corresponding hardware MAC address to construct a valid Ethernet frame. The sending host broadcasts an ARP request packet asking the owner of the target IP address to reply with its MAC address, enabling successful frame encapsulation and transmission.

Question 194

Which OSI layer handles logical addressing and packet routing across internetworks?

1. Physical Layer
2. Data Link Layer
3. Network Layer
4. Transport Layer

Correct Answer: 3

Explanation:

The Network layer, which is Layer 3 of the OSI reference model, is fundamentally responsible for logical addressing, path determination, and packet forwarding across disparate internetworks. Protocols operating at this layer, such as IPv4 and IPv6, assign unique logical addresses to host interfaces and utilize routing tables to determine the most efficient path for data packets to travel from source to destination. By abstracting physical hardware details, the network layer enables seamless internetwork communication across heterogeneous physical media types and complex routing topologies.

Question 195

What is the maximum distance for standard UTP copper cabling runs?

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 196

Which protocol reports network error conditions and operational diagnostics?

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 reply messages to test connectivity, while ICMP error reporting messages are generated automatically by routers and hosts when packet delivery fails. Examples include destination unreachable alerts, time exceeded notifications for expired TTL counters, and source quench messages, providing vital feedback for troubleshooting and maintaining healthy network operations.

Question 197

What command saves the active running configuration to persistent NVRAM?

1. copy running-config startup-config
2. copy startup-config running-config
3. write erase
4. reload system

Correct Answer: 1

Explanation:

The copy running-config startup-config command is executed in privileged EXEC mode within the Cisco IOS command-line interface to save the active configuration currently residing in random-access memory to non-volatile random-access memory. When a network device experiences a power loss or reboot, volatile RAM contents are wiped clean, while NVRAM contents persist across reboots. Therefore, administrators must explicitly save active configuration modifications to the startup configuration file using this command to ensure that recent interface changes, routing policies, and security settings are successfully loaded upon the next system boot.

Question 198

Which device operates at Layer 1 and simply regenerates electrical signals?

1. Layer 2 Switch
2. Enterprise 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 an electrical or optical signal 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, potential frame collisions, and performance degradation in busy network environments.

Question 199

What protocol secures remote device management sessions over encrypted connections?

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 utilized as a secure replacement for legacy Telnet sessions when network 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 intercepted easily, SSH encrypts all transmitted data streams using advanced cryptographic algorithms. This ensures that sensitive management traffic remains completely private and protected against unauthorized eavesdropping and man-in-the-middle attacks across both local and wide area networks.

Question 200

Which networking device creates separate collision domains for each individual 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.