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

 

Question 141

What is the standard IPv6 loopback address used by a host to test its own network stack?

1. ::1
2. 127.0.0.1
3. fe80::1
4. ::ffff:0:1

Correct Answer: 1

Explanation:

In IPv6 architecture, the loopback address is represented as ::1, which is equivalent to the IPv4 loopback address of 127.0.0.1. When a host transmits a packet to ::1, the network stack processes the packet internally without sending any traffic out across physical network interfaces. This address is used by applications and network administrators to verify that the local TCP/IP protocol stack is properly installed, configured, and functioning correctly on the host operating system.

Question 142

Which protocol is utilized to synchronize system clocks across computer networks?

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

Correct Answer: 2

Explanation:

The Network Time Protocol is a core networking protocol designed to synchronize the internal clocks of computers, routers, switches, and other devices over packet-switched data networks. Maintaining accurate time synchronization is critical for enterprise environments to ensure precise log correlation, reliable security auditing, digital certificate validation, and synchronized operations across distributed database systems. NTP typically operates over User Datagram Protocol port 123, communicating hierarchically with high-precision time servers.

Question 143

What wildcard mask corresponds to a standard IPv4 subnet mask of 255.255.255.0 when configuring Access Control Lists?

1. 0.0.0.0
2. 0.0.0.255
3. 255.255.255.0
4. 255.255.255.255

Correct Answer: 2

Explanation:

When configuring Access Control Lists on Cisco routers, wildcard masks are utilized instead of traditional subnet masks to specify ranges of IP addresses. A wildcard mask is the inverse of a subnet mask, where binary zeros indicate that the corresponding IP address bits must match exactly, and binary ones indicate wildcard tolerance. For a subnet mask of 255.255.255.0, inverting every bit transforms the decimal values to 0.0.0.255, matching any host within the final 8-bit octet of that network segment.

Question 144

Which Cisco IOS command displays the active configuration currently stored in NVRAM?

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

Correct Answer: 2

Explanation:

The show startup-config command is executed in privileged EXEC mode within the Cisco IOS command-line interface to inspect the configuration file saved in non-volatile random-access memory. Unlike the running configuration, which resides in active RAM and is lost upon device reboot, the startup configuration represents the saved state that will be loaded when the device initializes. Network engineers use this command to verify whether recent configuration changes have been successfully saved to persistent memory.

Question 145

What is the primary operational advantage of deploying a multilayer switch in an enterprise network?

1. Encrypting all wireless data payloads against eavesdropping.
2. Providing high-speed Layer 2 switching and inter-VLAN Layer 3 routing.
3. Automatically assigning dynamic IP lease addresses to workstations.
4. Translating private internal addresses into public routable IPs.

Correct Answer: 2

Explanation:

A multilayer switch combines traditional hardware-based Layer 2 Ethernet frame switching with high-performance Layer 3 packet routing within a single device. By utilizing specialized Application-Specific Integrated Circuits, a multilayer switch can process inter-VLAN routing traffic at wire speeds without the latency penalty associated with external routers. This capability makes multilayer switches ideal for enterprise distribution and core layers where dense port configurations and rapid routing performance are required.

Question 146

Which IEEE standard defines wireless local area networks operating in the 2.4 GHz and 5 GHz frequency bands?

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

Correct Answer: 3

Explanation:

The IEEE 802.11 standard family governs wireless local area network technologies, defining the physical layer and medium access control specifications for wireless data communications. Over time, the 802.11 standard has evolved through various amendments such as 802.11b, 802.11a, 802.11g, 802.11n, and 802.11ac to deliver higher throughput, improved modulation techniques, and expanded frequency band utilization across 2.4 GHz and 5 GHz spectra.

Question 147

What field in the IPv4 header is utilized for Quality of Service classification and packet prioritization?

1. Time to Live
2. Differentiated Services Code Point
3. Protocol Identifier
4. Header Checksum

Correct Answer: 2

Explanation:

The Differentiated Services field, formerly known as the Type of Service field in the IPv4 header, is an 8-bit field utilized for Quality of Service packet classification and marking. Network administrators use the Differentiated Services Code Point values within this field to prioritize critical traffic types—such as Voice over IP and real-time video streaming—over standard best-effort traffic, ensuring lower latency and minimal jitter across congested enterprise network links.

Question 148

Which TCP port is utilized by default for secure web browsing over HTTPS?

1. Port 80
2. Port 443
3. Port 22
4. Port 53

Correct Answer: 2

Explanation:

Hypertext Transfer Protocol Secure utilizes TCP port 443 by default for encrypted web communications. While standard HTTP operates unencrypted over TCP port 80, HTTPS combines HTTP with Transport Layer Security or Secure Sockets Layer protocols to encrypt all transmitted data payloads, protect user authentication credentials, and ensure data integrity between web browsers and web servers.

Question 149

What is the primary functional difference between a Standard Access Control List and an Extended Access Control List?

1. Standard ACLs filter traffic based on source IP addresses only, while Extended ACLs filter on source, destination, protocol, and port numbers.
2. Standard ACLs operate at Layer 3, while Extended ACLs operate exclusively at Layer 2.
3. Standard ACLs are applied inbound only, whereas Extended ACLs are applied outbound only.
4. Standard ACLs use named parameters, while Extended ACLs use numbered parameters only.

Correct Answer: 1

Explanation:

Standard Access Control Lists evaluate incoming packets based solely on the source IP address, filtering traffic broadly without regard to destination or application type. In contrast, Extended Access Control Lists provide granular traffic filtering capabilities by inspecting source IP addresses, destination IP addresses, specific network layer protocols, and upper-layer transport ports, allowing administrators to enforce precise security policies and traffic control.

Question 150

Which Cisco IOS global configuration command enables encryption for all plain-text passwords stored in configuration files?

1. enable secret password
2. service password-encryption
3. line console 0 password
4. crypto key generate rsa

Correct Answer: 2

Explanation:

The service password-encryption command is a global configuration command in Cisco IOS that applies a weak cryptographic algorithm to obfuscate all plain-text passwords—such as console, auxiliary, and vty passwords—stored within running and startup configuration files. While this prevents casual observers from reading passwords in plain text on screen or in configuration backups, administrators should use the enable secret command for secure cryptographic password hashing on privileged EXEC access.

Question 151

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

1. Encrypting all data frames crossing trunk links.
2. Acting as the reference point for all path cost calculations in the switched topology.
3. Automatically assigning IP addresses to client workstations.
4. Translating private internal IP addresses into public routable IPs.

Correct Answer: 2

Explanation:

In Spanning Tree Protocol, the root bridge serves as the central focal point and reference node for the entire switched network topology. Every switch in the bridged domain calculates its path cost to reach this designated root bridge. Ports leading toward the root bridge are elected as root ports, while redundant paths are placed into a blocking state to eliminate loops. The switch with the lowest bridge priority and MAC address combination wins the root bridge election.

Question 152

Which IPv4 address belongs to the private address range defined in RFC 1918?

1. 8.8.8.8
2. 172.16.10.5
3. 192.168.255.256
4. 11.0.0.1

Correct Answer: 2

Explanation:

RFC 1918 defines specific blocks of IPv4 address space reserved for private internal networks that are not routable across the public internet. These reserved ranges include 10.0.0.0 to 10.255.255.255, 172.16.0.0 to 172.31.255.255, and 192.168.0.0 to 192.168.255.255. Among the options provided, 172.16.10.5 falls within the designated Class B private range, allowing organizations to reuse internal IP addresses while employing Network Address Translation for internet access.

Question 153

What is the standard maximum transmission unit size for an unfragmented Ethernet frame?

1. 576 bytes
2. 1500 bytes
3. 4096 bytes
4. 9000 bytes

Correct Answer: 2

Explanation:

The standard Maximum Transmission Unit size for an unfragmented Ethernet frame data payload is 1500 bytes. When combined with the 14-byte Ethernet header and the 4-byte Frame Check Sequence trailer, a standard standard Ethernet frame totals 1518 bytes. While jumbo frames can extend this payload limit to 9000 bytes or more on specialized high-speed switching infrastructure, 1500 bytes remains the universal baseline MTU across standard enterprise networking gear.

Question 154

Which protocol is used to monitor and manage network devices, operating primarily over UDP ports 161 and 162?

1. Simple Network Management Protocol
2. Secure Shell Protocol
3. Network Time Protocol
4. Trivial File Transfer Protocol

Correct Answer: 1

Explanation:

Simple Network Management Protocol is an application-layer protocol used for monitoring and managing network-attached devices such as routers, switches, servers, and printers. SNMP utilizes User Datagram Protocol port 161 for agent polling requests and responses, and UDP port 162 for asynchronous alert notifications known as traps sent from managed devices back to a central network management station.

Question 155

What term describes the undesirable electrical signal interference caused by electromagnetic coupling between adjacent wire pairs in a copper cable?

1. Attenuation
2. Crosstalk
3. Latency
4. Jitter

Correct Answer: 2

Explanation:

Crosstalk is an electromagnetic phenomenon where a signal transmitted on one electrical circuit or wire pair creates an unwanted coupling effect on an adjacent circuit or wire pair. In unshielded twisted pair copper cabling, twisting the wire pairs tightly together helps cancel out external electromagnetic interference and internal crosstalk. Exceeding cabling distance limitations or improper termination can amplify crosstalk, leading to high bit error rates and network packet loss.

Question 156

Which Cisco IOS command mode is required to execute global configuration changes that affect the entire device?

1. User EXEC mode
2. Privileged EXEC mode
3. Global Configuration mode
4. Interface Configuration mode

Correct Answer: 3

Explanation:

Global Configuration mode is the centralized command mode in the Cisco IOS operating system where administrative changes affecting the entire device—such as setting the device hostname, configuring routing protocols, creating VLANs, or setting global security parameters—are executed. Administrators transition into this mode from privileged EXEC mode by typing the command configure terminal. Subsequent sub-modes, such as interface or line configuration modes, are accessed from within global configuration mode.

Question 157

What is the primary purpose of configuring a Syslog server in an enterprise environment?

1. Automatically assigning dynamic IP leases to client workstations.
2. Centrally collecting, storing, and analyzing system event logs and security alerts from network devices.
3. Resolving human-readable domain names into numerical IP addresses.
4. Translating private internal IP addresses into public routable addresses.

Correct Answer: 2

Explanation:

Syslog is a standardized protocol used by network devices, servers, and operating systems to transmit system log messages and security event notifications across an IP network to a centralized logging server. By aggregating logs from multiple routers, switches, and firewalls into a single repository, systems administrators can perform real-time monitoring, conduct forensic troubleshooting, and detect unauthorized security intrusion attempts efficiently.

Question 158

Which dynamic routing protocol is classified as an exterior gateway protocol and operates across the public internet between autonomous systems?

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

Correct Answer: 4

Explanation:

Border Gateway Protocol is an exterior gateway path-vector routing protocol designed to exchange routing and reachability information between distinct autonomous systems across the global internet. Unlike interior gateway protocols like OSPF or EIGRP that optimize path metrics within a single organization, BGP makes routing decisions based on path attributes, network policies, and autonomous system hop paths, serving as the foundational routing protocol of the internet backbone.

Question 159

What is the block size (total addresses per subnet) for an IPv4 subnet with a subnet mask of 255.255.255.224?

1. 16 addresses
2. 32 addresses
3. 64 addresses
4. 128 addresses

Correct Answer: 2

Explanation:

To determine the block size of an IPv4 subnet, subtract the decimal value of the final octet of the subnet mask from 256. For a subnet mask of 255.255.255.224, the final octet is 224. Subtracting 224 from 256 yields a block size of 32 total addresses per subnet. This corresponds to a /27 CIDR prefix, which provides 32 total addresses, of which 30 are usable for host device assignment after reserving the network identifier and broadcast addresses.

Question 160

Which IEEE standard defines Power over Ethernet, allowing electrical power to be transmitted alongside data over standard UTP copper cables?

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

Correct Answer: 1

Explanation:

The IEEE 802.3af standard, along with its higher-power successor 802.3at, defines Power over Ethernet technology. PoE enables network switches to transmit electrical direct current power alongside high-speed data signals over standard unshielded twisted pair copper cabling to powered devices such as IP security cameras, wireless access points, and VoIP desktop phones. This eliminates the need for separate electrical power wiring at every device installation location.