View Full Cisco 100-140 Exam Dumps and Practice Test Dumps

 

Question 1. Which command displays the IP configuration information on a Windows workstation?

1. ping
2. ipconfig
3. tracert
4. nslookup

Correct Answer: 2. ipconfig

Explanation :-

The ipconfig command displays IP configuration information on a Windows workstation, including the IPv4 or IPv6 address, subnet mask, and default gateway. Additional options such as /all provide more detailed information, including DNS servers and physical adapter details. The ping command is primarily used to test reachability, while tracert identifies the path packets take toward a destination. The nslookup command is used to query DNS information. Network administrators commonly use ipconfig as an initial troubleshooting command when verifying whether a workstation has received the expected network configuration.

Question 2. Which protocol is primarily responsible for automatically assigning IP addresses to network hosts?

1. DNS
2. FTP
3. DHCP
4. SSH

Correct Answer: 3. DHCP

Explanation :-

Dynamic Host Configuration Protocol (DHCP) automatically provides network configuration information to clients. A DHCP server can assign an IP address, subnet mask, default gateway, DNS server information, and other parameters according to its configuration. This reduces the need to manually configure every host and helps prevent duplicate addressing. DNS performs name resolution rather than IP address assignment. FTP is designed for file transfer, while SSH provides secure remote access. DHCP is especially useful in enterprise networks where large numbers of endpoints require consistent and centrally managed network configuration.

Question 3. Which device forwards Ethernet frames based primarily on MAC addresses?

1. Router
2. Firewall
3. Switch
4. Modem

Correct Answer: 3. Switch

Explanation :-

An Ethernet switch forwards frames by examining destination MAC addresses and using its MAC address table to determine the appropriate interface. When a switch learns the source MAC address of an incoming frame, it associates that address with the receiving port. This allows subsequent frames destined for that MAC address to be forwarded efficiently. Routers primarily make forwarding decisions using Layer 3 IP information, while firewalls enforce security policies based on configured traffic rules. A modem performs signal conversion and access functions depending on the network technology. Understanding the switch’s MAC-based forwarding behavior is fundamental to Ethernet network operation.

Question 4. Which IPv4 address is in a private address range?

1. 8.8.8.8
2. 172.20.10.5
3. 198.51.100.10
4. 203.0.113.25

Correct Answer: 2. 172.20.10.5

Explanation :-

The IPv4 private address ranges defined for private network use include 10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16. The address 172.20.10.5 falls within the 172.16.0.0 through 172.31.255.255 range and is therefore private. Private addresses are commonly used inside organizational networks and are not directly routable across the public Internet. Addresses such as 8.8.8.8 are publicly routable, while 198.51.100.0/24 and 203.0.113.0/24 are reserved for documentation and examples. Identifying address ranges is important when configuring routing, NAT, and network security.

Question 5. Which command is commonly used on Cisco IOS to display the current running configuration?

1. show running-config
2. show interfaces status
3. show ip route
4. show version

Correct Answer: 1. show running-config

Explanation :-

The show running-config command displays the configuration currently active in RAM on a Cisco IOS device. It is commonly used to inspect configured interfaces, routing protocols, access control lists, passwords, and other operational settings. show startup-config instead displays the configuration saved in NVRAM, which is normally loaded when the device boots. show ip route displays the routing table, while show version provides software, hardware, uptime, and related system information. Understanding the distinction between running and startup configurations is important because changes made to the running configuration may be lost after a reboot if they are not saved.

Question 6. What is the primary purpose of a default gateway on an IPv4 host?

1. To resolve domain names
2. To provide MAC addresses
3. To forward traffic destined for remote networks
4. To assign the host an IP address

Correct Answer: 3. To forward traffic destined for remote networks

Explanation :-

A default gateway provides an IPv4 host with a next-hop device, normally a router, for destinations outside the host’s local subnet. When a host determines that the destination address is not part of its directly connected network, it sends the packet to the configured default gateway. The router can then forward the traffic toward the remote network. DNS handles domain-name resolution, while DHCP can provide IP configuration parameters. A switch may provide local Layer 2 connectivity but does not normally serve as the default gateway unless it has Layer 3 routing capability. Correct gateway configuration is essential for communication beyond the local subnet.

Question 7. Which protocol translates a domain name such as www.example.com into an IP address?

1. DNS
2. DHCP
3. ARP
4. NTP

Correct Answer: 1. DNS

Explanation :-

The Domain Name System (DNS) translates human-readable domain names into IP addresses and can also provide other types of name-related information. When a user enters a domain name, a DNS resolver can query DNS infrastructure to obtain the corresponding address record. DHCP is responsible for dynamically assigning network configuration information, while ARP maps an IPv4 address to a MAC address on a local network. NTP synchronizes system clocks. DNS is therefore a fundamental service for Internet and enterprise applications because users and applications can use names instead of having to remember numerical IP addresses.

Question 8. Which IPv6 address type is used for communication with all nodes on the local link?

1. FF02::2
2. FF02::1
3. FE80::1
4. 2001:db8::1

Correct Answer: 2. FF02::1

Explanation :-

The IPv6 multicast address FF02::1 represents all nodes on the local link. Packets sent to this multicast address are delivered to IPv6 nodes that have joined the corresponding multicast group on that link. FF02::2 represents all IPv6 routers on the local link. Addresses beginning with FE80::/10 are link-local addresses and are used for communication on the local link, but they are unicast rather than the all-nodes multicast address. 2001:db8::/32 is reserved for documentation. Understanding IPv6 multicast addresses is important for neighbor discovery and other IPv6 network operations.

Question 9. Which OSI layer is responsible for logical addressing using IP addresses?

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

Correct Answer: 3. Network

Explanation :-

The Network layer, Layer 3 of the OSI model, is responsible for logical addressing and routing. IPv4 and IPv6 addresses operate at this layer, allowing routers to make forwarding decisions between different networks. The Data Link layer handles local frame delivery and technologies such as Ethernet MAC addressing. The Physical layer deals with transmission of bits over a physical medium, while the Transport layer provides functions such as end-to-end delivery using protocols such as TCP and UDP. Understanding OSI layers helps network administrators identify where a connectivity problem or protocol function operates.

Question 10. Which transport-layer protocol provides reliable, connection-oriented communication?

1. UDP
2. ICMP
3. ARP
4. TCP

Correct Answer: 4. TCP

Explanation :-

Transmission Control Protocol (TCP) provides connection-oriented and reliable transport services. It establishes a connection using a handshake process and uses sequence numbers, acknowledgments, retransmissions, and flow-control mechanisms to support reliable delivery. User Datagram Protocol (UDP) is connectionless and does not provide TCP’s built-in reliability mechanisms. ICMP is used for network-layer control and diagnostic messaging, while ARP is used to resolve IPv4 addresses to MAC addresses on local networks. Applications such as web services, email, and file transfers may use TCP when reliable, ordered delivery is required.

Question 11. Which Cisco IOS command displays a summary of IPv4 addresses and interface status?

1. show ip interface brief
2. show vlan brief
3. show arp
4. show cdp neighbors

Correct Answer: 1. show ip interface brief

Explanation :-

The show ip interface brief command provides a concise overview of router or Layer 3 switch interfaces. It commonly displays each interface, its assigned IP address, and the status and protocol state. This makes the command useful for quickly identifying interfaces that are administratively down, operationally down, or functioning normally. show vlan brief focuses on VLAN information, show arp displays ARP entries, and show cdp neighbors provides information about directly connected Cisco devices discovered through CDP. During initial troubleshooting, show ip interface brief is often useful for rapidly checking interface and addressing status.

Question 12. What does a VLAN primarily provide on a Layer 2 switch?

1. Physical separation of switch hardware
2. Logical segmentation of a Layer 2 network
3. Automatic encryption of Ethernet frames
4. Replacement of IP routing

Correct Answer: 2. Logical segmentation of a Layer 2 network

Explanation :-

A Virtual LAN (VLAN) logically separates a switched network into distinct Layer 2 broadcast domains. Devices assigned to different VLANs are logically separated even when they are connected to the same physical switch infrastructure. Communication between different VLANs requires Layer 3 routing, commonly through a router or multilayer switch. VLANs do not inherently encrypt Ethernet traffic or replace IP routing. They are widely used to organize users and devices, reduce broadcast-domain size, and support network segmentation. Proper VLAN configuration also helps administrators apply different policies and services to different logical groups of devices.

Question 13. Which command tests whether a remote IP host is reachable using ICMP Echo messages?

1. telnet
2. ping
3. ssh
4. ftp

Correct Answer: 2. ping

Explanation :-

The ping command uses ICMP Echo Request and Echo Reply messages to test IP-level reachability between hosts. It can help determine whether a destination responds and can provide information about round-trip time and packet loss. A failed ping does not always prove that a destination is unreachable because firewalls or security policies may block ICMP messages. Telnet and SSH are remote-access protocols, while FTP is used for file transfer. Ping is nevertheless one of the most common first-line diagnostic tools for testing basic network connectivity and identifying whether further troubleshooting is required.

Question 14. Which wireless standard operates in both the 2.4 GHz and 5 GHz frequency bands?

1. 802.11b
2. 802.11a
3. 802.11g
4. 802.11n

Correct Answer: 4. 802.11n

Explanation :-

IEEE 802.11n can operate in both the 2.4 GHz and 5 GHz frequency bands, depending on the implementation and configuration. It introduced improvements such as MIMO and channel bonding to increase wireless performance compared with earlier standards. 802.11b and 802.11g primarily operate in the 2.4 GHz band, while 802.11a operates in the 5 GHz band. Wireless administrators must consider frequency selection, channel availability, interference, client capabilities, and deployment requirements when configuring WLANs. Understanding which standards support each frequency band helps when planning compatibility and wireless coverage.

Question 15. What is the purpose of ARP in an IPv4 Ethernet network?

1. To map an IPv4 address to a MAC address
2. To assign an IPv4 address dynamically
3. To encrypt IP packets
4. To calculate the shortest routing path

Correct Answer: 1. To map an IPv4 address to a MAC address

Explanation :-

Address Resolution Protocol (ARP) is used in IPv4 Ethernet networks to determine the MAC address associated with a known IPv4 address on the local network. When a host needs to send a frame to an IPv4 destination on the local subnet, it can use ARP to discover the destination MAC address. The resulting mapping may be stored temporarily in an ARP cache. DHCP assigns network configuration, encryption is handled by appropriate security protocols, and routing protocols determine paths between networks. ARP is therefore an important mechanism connecting Layer 3 IPv4 addressing with Layer 2 Ethernet delivery.

Question 16. Which subnet mask corresponds to the IPv4 prefix length /24?

1. 255.255.0.0
2. 255.255.255.128
3. 255.255.255.0
4. 255.255.255.252

Correct Answer: 3. 255.255.255.0

Explanation :-

An IPv4 /24 prefix contains 24 network bits and 8 host bits. Its dotted-decimal subnet mask is 255.255.255.0. This provides 256 total IPv4 addresses in the subnet, although traditional IPv4 subnetting reserves the network and broadcast addresses, leaving 254 addresses for hosts in a typical /24 subnet. A /25 uses 255.255.255.128, a /30 uses 255.255.255.252, and /16 uses 255.255.0.0. Correctly understanding prefix lengths and subnet masks is essential for IP addressing, subnet design, routing, and troubleshooting.

Question 17. Which Cisco IOS mode allows an administrator to configure global device settings?

1. User EXEC mode
2. Privileged EXEC mode
3. Global configuration mode
4. ROM monitor mode

Correct Answer: 3. Global configuration mode

Explanation :-

Global configuration mode is used to configure settings that affect the Cisco IOS device as a whole. An administrator normally enters it from privileged EXEC mode using the configure terminal command. From global configuration mode, the administrator can enter specific configuration submodes for interfaces, lines, routing protocols, VLANs, and other features. User EXEC mode provides limited monitoring access, while privileged EXEC mode provides access to higher-level operational commands and the ability to enter configuration mode. ROM monitor mode is primarily associated with low-level recovery and boot functions rather than routine device configuration.

Question 18. Which protocol is commonly used to securely access the command-line interface of a Cisco device remotely?

1. FTP
2. SSH
3. TFTP
4. HTTP

Correct Answer: 2. SSH

Explanation :-

Secure Shell (SSH) provides encrypted remote command-line access to network devices. It protects authentication information and interactive management traffic from being transmitted in clear text. Cisco administrators commonly configure SSH for secure remote management instead of relying on Telnet, which does not provide the same encryption for management sessions. FTP and TFTP are primarily file-transfer protocols, while HTTP provides web-based communication. Secure remote management is an important network security practice because administrative credentials and configuration commands can contain sensitive information.

Question 19. What is the primary purpose of NAT in an IPv4 network?

1. To translate between private and public IPv4 addresses
2. To replace Ethernet switching
3. To synchronize network clocks
4. To resolve hostnames into MAC addresses

Correct Answer: 1. To translate between private and public IPv4 addresses

Explanation :-

Network Address Translation (NAT) modifies IP addressing information as traffic passes between network boundaries. A common use is translating private IPv4 addresses used inside an organization into public IPv4 addresses for Internet communication. NAT can allow many internal hosts to share one or more public addresses, depending on the implementation. NAT does not replace Ethernet switching, synchronize clocks, or perform hostname-to-MAC resolution. Network administrators use different NAT forms, including static NAT, dynamic NAT, and Port Address Translation, to meet addressing and connectivity requirements.

Question 20. Which statement describes a broadcast domain?

1. A group of devices that receives all unicast frames
2. A group of interfaces connected only through fiber
3. A group of devices that can receive a Layer 2 broadcast without a Layer 3 boundary intervening
4. A group of routers that share the same routing protocol

Correct Answer: 3. A group of devices that can receive a Layer 2 broadcast without a Layer 3 boundary intervening

Explanation :-

A broadcast domain is a logical portion of a network in which a Layer 2 broadcast can reach participating devices without crossing a Layer 3 routing boundary. VLANs are commonly used to create separate broadcast domains on switches. Routers normally separate broadcast domains because broadcasts are not forwarded between interfaces by default. A broadcast domain is not defined by the physical transmission medium or by the routing protocol used between routers. Understanding broadcast domains is important when designing VLANs, controlling broadcast traffic, and determining where Layer 3 routing is required.