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Question 61

What is the function of the Spanning Tree Protocol root bridge?

1. Serving as the central reference point for calculating path costs across the switched topology.
2. Encrypting all data frames traversing through local area network trunk ports.
3. Automatically assigning IP addresses to client workstations connecting to switch ports.
4. Converting optical signals into electrical voltages across long-distance fiber links.

Correct Answer: 1

Explanation:

Within a switched network running the Spanning Tree Protocol, the root bridge serves as the logical center of the topology and acts as the reference point for all path cost calculations. Every switch in the bridged environment calculates its cumulative cost to reach this designated root bridge, ensuring that redundant physical links can be intelligently managed and blocked to prevent catastrophic broadcast storms. The bridge election process occurs automatically using bridge priorities and switch MAC addresses, identifying the device with the lowest priority value as the root bridge. This centralized reference point guarantees a stable, loop-free logical topology while maintaining high availability through automated path recalculation if primary links fail.

Question 62

Which command displays Cisco IOS software version and memory statistics?

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

Correct Answer: 2

Explanation:

The show version command is an essential diagnostic tool executed within the Cisco IOS command-line interface to retrieve vital hardware, software, and system telemetry data from a router or switch. When entered in privileged EXEC mode, it displays the exact Cisco IOS software image version currently running, system uptime statistics, configuration register settings, hardware platform model identification, amount and type of system memory installed, and interface hardware counts. Network engineers rely heavily on the show version command during inventory audits, software upgrade planning, and initial troubleshooting sessions to verify device specifications and system stability.

Question 63

What protocol provides dynamic router advertisement in IPv6 networks?

1. Dynamic Host Configuration Protocol version 6
2. Internet Control Message Protocol version 6 Neighbor Discovery
3. Address Resolution Protocol version 6
4. Routing Information Protocol next generation

Correct Answer: 2

Explanation:

In IPv6 networks, the Neighbor Discovery Protocol operating via Internet Control Message Protocol version 6 handles essential node-to-node communication, address resolution, and router discovery functions. Unlike IPv4 networks where hosts rely primarily on DHCP servers or static configurations for gateway details, IPv6 hosts utilize ICMPv6 Router Advertisement messages sent periodically by local routers. These advertisements supply critical network prefixes, default gateway addresses, and configuration flags that enable nodes to perform stateless address autoconfiguration seamlessly without requiring manual intervention or complex stateful server tracking across the local segment.

Question 64

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

1. Layer 2 Ethernet Switch
2. Traditional Network Hub
3. Enterprise Core Router
4. Passive Patch Panel

Correct Answer: 3

Explanation:

An enterprise core router operates primarily at Layer 3, the network layer of the OSI reference model. Its core responsibility is to examine incoming data packets, analyze destination IP addresses, evaluate routing tables and dynamic routing protocols, and forward packets across disparate network segments. Unlike Layer 2 switches that manage traffic within a single local area network using hardware MAC addresses, Layer 3 routers bridge distinct networks together, perform packet encapsulation adjustments, enforce security filtering, and manage traffic flow across wide area connections, making them foundational pillars of internetwork routing architecture.

Question 65

What is the primary function of the Network Time Protocol?

1. Synchronizing internal clocks of network devices across a common reference source.
2. Translating domain names into numerical IP addresses for packet forwarding.
3. Dynamically allocating IP address leases to client workstations on demand.
4. Monitoring interface error rates and CPU utilization metrics across routers.

Correct Answer: 1

Explanation:

The Network Time Protocol is a critical networking protocol designed to synchronize the clocks of computers, routers, switches, and servers over packet-switched data networks. Accurate time synchronization is indispensable for modern enterprise environments, as it enables precise log correlation, reliable security certificate validation, accurate billing records, and synchronized troubleshooting across distributed systems. NTP utilizes a hierarchical stratum architecture, allowing devices to reference highly accurate primary time sources such as atomic clocks or GPS receivers, ensuring that all network equipment operates with consistent, synchronized time stamps.

Question 66

Which IPv4 address type is used for broadcasting packets locally?

1. 127.0.0.1
2. 255.255.255.255
3. 192.168.1.1
4. 10.0.0.1

Correct Answer: 2

Explanation:

The IPv4 address 255.255.255.255 is designated as the limited broadcast address within internet protocol architecture. When a host transmits a packet destined for this specific address, the transmission is restricted to the local network segment and is never forwarded across routers by design. Network devices on the local segment process the broadcast packet immediately. This address is frequently utilized by bootstrap protocols, client discovery mechanisms, and service location requests where the sending node does not yet know the specific subnet mask or network identifier of its local environment.

Question 67

What mechanism prevents routing loops in distance-vector routing protocols?

1. Encrypting routing update packets using pre-shared cryptographic keys.
2. Implementing split horizon and route poisoning techniques.
3. Assigning a static administrative distance of one to all paths.
4. Requiring manual administrator approval for every route calculation.

Correct Answer: 2

Explanation:

Distance-vector routing protocols are inherently vulnerable to routing loops and slow convergence issues where incorrect metric updates circulate indefinitely. To mitigate these risks, protocols like RIP and EIGRP implement robust preventative mechanisms such as split horizon, route poisoning, and poisoned reverse. Split horizon ensures that a router never advertises a route back out the exact same interface it learned that route from, preventing feedback loops. Route poisoning actively advertises unreachable routes with an infinite metric, while hold-down timers give networks sufficient time to stabilize during topology changes.

Question 68

Which command saves the active running configuration to startup memory?

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

Correct Answer: 2

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 69

What protocol securely transfers files over encrypted SSH tunnels?

1. Trivial File Transfer Protocol
2. Secure File Transfer Protocol
3. File Transfer Protocol
4. Hypertext Transfer Protocol

Correct Answer: 2

Explanation:

Secure File Transfer Protocol is a network protocol designed to provide secure file transfer, file management, and file access capabilities over any reliable stream. Unlike legacy File Transfer Protocol, which transmits authentication credentials and data payloads in clear text across insecure networks, SFTP operates as a subsystem of Secure Shell, leveraging its robust encryption mechanisms. All data streams, passwords, and file contents are fully encrypted during transit, protecting sensitive organizational files against eavesdropping, interception, and tampering by malicious actors across both local and wide area networks.

Question 70

Which IEEE standard defines rapid spanning tree protocol operations?

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

Correct Answer: 3

Explanation:

The IEEE 802.1W standard formally defines the Rapid Spanning Tree Protocol, an evolutionary enhancement to the original IEEE 802.1D Spanning Tree Protocol. While traditional STP can take up to fifty seconds to transition ports through listening and learning states during a topology change, RSTP introduces rapid convergence capabilities that reduce failover times to mere milliseconds. By introducing new port roles and alternative path states, RSTP actively negotiates link status between adjacent switches, eliminating unnecessary delays and ensuring high availability across modern high-performance enterprise switching infrastructures.

Question 71

What is the primary benefit of deploying VLANs in switches?

1. Encrypting wireless data frames against unauthorized third-party interception.
2. Logically segmenting broadcast domains to improve network performance and security.
3. Automatically converting private IP addresses into public routable addresses.
4. Amplifying electrical signals across long copper cabling runs.

Correct Answer: 2

Explanation:

Deploying Virtual Local Area Networks allows network engineers to logically partition a physical switched infrastructure into multiple distinct broadcast domains. By grouping switch ports and connected devices according to department, security clearance, or operational function rather than physical location, organizations drastically reduce unnecessary broadcast traffic overhead. This logical isolation enhances overall network performance, optimizes bandwidth utilization, and strengthens security by preventing unauthorized lateral movement between isolated departmental segments without requiring dedicated physical switches for every unique network group.

Question 72

Which memory type stores the bootstrap startup configuration permanently?

1. Random Access Memory
2. Read-Only Memory
3. Non-Volatile Random Access Memory
4. Flash Memory

Correct Answer: 3

Explanation:

Non-Volatile Random Access Memory is a specialized type of computer memory used inside Cisco routers and switches to store the startup configuration file persistently. Unlike volatile RAM, which loses all data whenever power is interrupted or the device reboots, NVRAM retains its stored contents indefinitely without requiring constant electrical power. When a network device boots up, the operating system copies this startup configuration file from NVRAM into RAM, where it becomes the active running configuration that dictates ongoing device operations and routing behavior.

Question 73

What protocol resolves hostnames into numerical IP addresses dynamically?

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

Correct Answer: 2

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 74

Which layer of the OSI model ensures reliable packet delivery?

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

Correct Answer: 3

Explanation:

The Transport layer, which is Layer 4 of the OSI reference model, is fundamentally responsible for providing reliable, transparent, and error-checked end-to-end data delivery between communicating hosts. Protocols operating at this layer, such as Transmission Control Protocol, establish connection-oriented sessions, implement flow control mechanisms, utilize windowing to optimize bandwidth utilization, and perform error detection and retransmission of lost segments. This ensures that application data streams are delivered accurately, in correct sequence, and without corruption regardless of the underlying physical network infrastructure traversed.

Question 75

What is the default administrative distance of internal EIGRP?

1. 1
2. 90
3. 110
4. 120

Correct Answer: 2

Explanation:

Administrative distance represents the trustworthiness or preference level of a routing information source, where lower values indicate higher reliability in path selection. In Cisco IOS routing architecture, internal Enhanced Interior Gateway Routing Protocol routes are assigned a default administrative distance of 90. This value positions internal EIGRP as more preferred than OSPF at 110 and RIP at 120, but less preferred than static routes at 1. Understanding these default values is crucial for network engineers designing multi-protocol routing environments, fallback paths, and traffic engineering strategies across enterprise networks.

Question 76

Which protocol monitors network device health and operational status?

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

Correct Answer: 1

Explanation:

The Simple Network Management Protocol is an application-layer protocol utilized extensively in enterprise network management systems to monitor, configure, and track the operational health of network devices. SNMP allows network administrators to collect vital telemetry data—including CPU utilization, interface error counters, memory consumption, temperature thresholds, and traffic throughput volumes—from routers, switches, firewalls, and servers. By utilizing management information bases and variable bindings, SNMP agents report status updates and trap alerts to centralized management stations, enabling proactive incident detection and rapid troubleshooting.

Question 77

What command verifies active serial or Ethernet interface configurations?

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

Correct Answer: 2

Explanation:

The show running-config interface command is a targeted diagnostic command executed within the Cisco IOS command-line interface to inspect the precise configuration parameters applied to a specific physical or logical interface. While show ip interface brief provides a high-level summary table of all ports, drilling down with show running-config interface details exact line encapsulation methods, assigned IP subnet masks, access-group filters, speed and duplex settings, shutdown states, and routing protocol parameters. This command is invaluable for verifying granular port settings during troubleshooting and deployment tasks.

Question 78

Which routing metric is utilized by the Routing Information Protocol?

1. Bandwidth
2. Delay
3. Hop count
4. Cost

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 79

What device connects multiple computers within a single broadcast domain?

1. Layer 2 Ethernet Switch
2. Border Gateway Router
3. Firewall Appliance
4. Wide Area Network Modulator

Correct Answer: 1

Explanation:

A Layer 2 Ethernet switch is designed to connect multiple computers, printers, and workstations together within a single local area network segment, forming a unified broadcast domain. By utilizing hardware MAC address tables and dedicated port-based switching paths, the switch facilitates high-speed data forwarding and full-duplex communication between connected endpoints. Unlike routers that divide networks and filter broadcast traffic, a Layer 2 switch propagates broadcast and multicast frames across all ports within the same VLAN, enabling local network nodes to discover services and communicate efficiently.

Question 80

Which protocol establishes a three-way handshake before data transmission?

1. User Datagram Protocol
2. Transmission Control Protocol
3. Internet Protocol
4. Internet Control Message Protocol

Correct Answer: 2

Explanation:

Transmission Control Protocol is a core transport layer protocol that provides reliable, connection-oriented data delivery across IP networks. Before any application payload data can be exchanged, TCP initiates a formal connection establishment procedure known as the three-way handshake. The client sends a synchronization segment, the server responds with a synchronization-acknowledgment segment, and the client concludes the handshake with an acknowledgment segment. This rigorous process synchronizes initial sequence numbers, establishes session parameters, and ensures that both communicating hosts are ready for reliable, error-checked data transfer.