Free CCNA Cisco Certified Network Associate Test

CCNA Practice Exam | Free Cisco Certified Network Associate Test Prep by Exam Sage

Are you preparing for the Cisco Certified Network Associate (CCNA) certification and looking for a comprehensive, reliable practice test to sharpen your networking skills? ExamSage.com offers this free CCNA Practice Exam designed to help you confidently master all the essential topics and ace your certification exam.

What is the CCNA Practice Exam?

The CCNA certification is one of the most respected and sought-after credentials in the IT networking world. It validates your knowledge of networking fundamentals, routing and switching technologies, security concepts, IP addressing, and more. Our CCNA Practice Exam simulates the real exam environment with carefully crafted multiple-choice questions and detailed explanations that help reinforce your learning.

What Will You Learn?

By taking this free CCNA Practice Exam, you will:

• Test your understanding of key networking concepts like IP addressing, subnetting, and routing protocols.

• Gain hands-on experience with Cisco command-line interface (CLI) configurations.

• Learn how to troubleshoot common network issues using real-world scenarios.

• Understand security fundamentals, VLANs, wireless networking, and network automation basics.

• Improve your confidence and time management skills for the actual CCNA certification exam.

Topics Covered in This Exam

Our CCNA Practice Exam covers the following critical areas:

• Network Fundamentals: OSI and TCP/IP models, IPv4/IPv6 addressing, cabling, and network device types.

• Routing and Switching: Static and dynamic routing protocols (OSPF, EIGRP), VLANs, trunking, Spanning Tree Protocol.

• Network Access: Switch port configuration, VLANs, wireless networking basics.

• IP Connectivity: IP routing, packet forwarding, ACLs, NAT.

• Security Fundamentals: Device hardening, VPNs, firewalls, network security best practices.

• Automation and Programmability: Network automation concepts, Cisco DNA Center basics, REST APIs.

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• Free Access: No cost to practice, no registration required.

• Detailed Explanations: Every question comes with in-depth answers to clarify concepts.

• Realistic Questions: Questions reflect the latest CCNA exam blueprint and difficulty level.

• User-Friendly Interface: Easy navigation and instant feedback for efficient studying.

Prepare smarter and boost your chances of passing the CCNA exam with confidence. Start practicing now with Exam Sage’s free CCNA Practice Exam and take the first step towards becoming a certified Cisco networking professional!

CCNA Exam Questions and Answers

1. Which layer of the OSI model is responsible for reliable data transfer and flow control?

A. Network
B. Transport
C. Data Link
D. Session

Correct Answer: B. Transport

Explanation:
The Transport layer (Layer 4) is responsible for end-to-end communication, reliable data transfer, and flow control. It uses protocols like TCP (for reliable communication) and UDP (for faster, less reliable communication).

2. What is the default administrative distance of an OSPF route?

A. 90
B. 100
C. 110
D. 120

Correct Answer: C. 110

Explanation:
Administrative distance (AD) is a measure of the trustworthiness of a route. OSPF has a default AD of 110, making it less preferred than EIGRP (90) but more than RIP (120).

3. Which command is used to display the current routing table on a Cisco router?

A. show interfaces
B. show ip route
C. show running-config
D. show protocols

Correct Answer: B. show ip route

Explanation:
The show ip route command is used to display the routing table, showing learned routes, their sources, and metrics.

4. What is the subnet mask for a /26 prefix?

A. 255.255.255.0
B. 255.255.255.192
C. 255.255.255.224
D. 255.255.255.128

Correct Answer: B. 255.255.255.192

Explanation:
A /26 subnet means 26 bits are used for the network. This gives a subnet mask of 255.255.255.192 and allows for 64 IP addresses per subnet.

5. Which protocol uses port 23 and transmits data in plaintext?

A. SSH
B. FTP
C. Telnet
D. SNMP

Correct Answer: C. Telnet

Explanation:
Telnet uses TCP port 23 and transmits data, including credentials, in plaintext. It’s largely deprecated in favor of SSH.

6. What is the primary purpose of VLANs in a switched network?

A. Enhance routing between subnets
B. Increase broadcast domains
C. Reduce latency
D. Reduce collision domains

Correct Answer: B. Increase broadcast domains

Explanation:
VLANs logically segment a network into multiple broadcast domains, allowing better management and security without additional physical devices.

7. Which command is used to assign an IP address to a Cisco router interface?

A. set ip address
B. interface ip address
C. ip address
D. assign ip

Correct Answer: C. ip address

Explanation:
Within interface configuration mode, use the ip address [address] [subnet mask] command to assign an IP address.

8. What type of NAT allows many internal IPs to share one public IP?

A. Static NAT
B. Dynamic NAT
C. PAT
D. DNAT

Correct Answer: C. PAT

Explanation:
Port Address Translation (PAT) allows multiple internal devices to share a single public IP by differentiating using port numbers.

9. Which protocol is used to automatically assign IP addresses to devices?

A. DNS
B. ARP
C. DHCP
D. ICMP

Correct Answer: C. DHCP

Explanation:
The Dynamic Host Configuration Protocol (DHCP) automatically assigns IP addresses and other network configuration details.

10. What is the loopback IP address used for?

A. Communicating with a remote server
B. Troubleshooting remote networks
C. Testing local TCP/IP stack
D. Creating VPN tunnels

Correct Answer: C. Testing local TCP/IP stack

Explanation:
The loopback address (127.0.0.1) is used to verify that the TCP/IP stack is functioning properly on the local machine.

11. What is the purpose of a default gateway?

A. Translate domain names
B. Provide internet to all devices
C. Route packets outside the local subnet
D. Encrypt traffic

Correct Answer: C. Route packets outside the local subnet

Explanation:
The default gateway is the device that routes traffic destined for networks outside the local subnet.

12. In a Class C network, how many usable host IPs are available with a /27 subnet?

A. 32
B. 30
C. 62
D. 64

Correct Answer: B. 30

Explanation:
A /27 subnet gives 32 IP addresses total. 2 are reserved (network and broadcast), leaving 30 usable IPs.

13. Which of the following is a class B private IP address?

A. 10.0.0.1
B. 172.16.5.4
C. 192.168.0.1
D. 169.254.1.1

Correct Answer: B. 172.16.5.4

Explanation:
The 172.16.0.0 – 172.31.255.255 range is private Class B. 10.0.0.0 is Class A, and 192.168.0.0 is Class C.

14. Which protocol is used by ping?

A. TCP
B. UDP
C. ICMP
D. ARP

Correct Answer: C. ICMP

Explanation:
Ping uses the Internet Control Message Protocol (ICMP) to send echo requests and receive echo replies.

15. Which switching method reads the entire frame before forwarding?

A. Cut-through
B. Fragment-free
C. Store-and-forward
D. Fast-forward

Correct Answer: C. Store-and-forward

Explanation:
Store-and-forward switching waits to receive the entire frame and checks for errors before forwarding it.

16. What is the primary benefit of using IPv6 over IPv4?

A. Faster data transmission
B. Improved routing protocols
C. Larger address space
D. Encrypted headers

Correct Answer: C. Larger address space

Explanation:
IPv6 provides a vastly larger address space (128-bit vs. 32-bit), accommodating the growing number of devices.

17. What does STP prevent in a switched network?

A. Broadcasts
B. IP conflicts
C. Routing loops
D. Switching loops

Correct Answer: D. Switching loops

Explanation:
Spanning Tree Protocol (STP) prevents switching loops by creating a loop-free logical topology.

18. Which WAN technology uses cell-switching and fixed-length packets?

A. Frame Relay
B. MPLS
C. ATM
D. ISDN

Correct Answer: C. ATM

Explanation:
Asynchronous Transfer Mode (ATM) uses fixed-length cells (53 bytes), ideal for voice and video.

19. Which part of an IPv6 address is used for subnetting?

A. First 32 bits
B. First 48 bits
C. First 64 bits
D. Last 64 bits

Correct Answer: C. First 64 bits

Explanation:
In most IPv6 networks, the first 64 bits define the network/subnet, while the last 64 identify the host/interface.

20. What command secures access to privileged EXEC mode in Cisco IOS?

A. enable password
B. line console 0
C. enable secret
D. login

Correct Answer: C. enable secret

Explanation:
enable secret encrypts the password used to enter privileged EXEC mode, offering greater security than enable password.

21. What is the purpose of CDP in Cisco networks?

A. Monitor traffic
B. Discover directly connected devices
C. Assign IP addresses
D. Filter MAC addresses

Correct Answer: B. Discover directly connected devices

Explanation:
Cisco Discovery Protocol (CDP) identifies directly connected Cisco devices, showing info like hostname and IP.

22. Which protocol is used to synchronize clocks between network devices?

A. ICMP
B. SNMP
C. NTP
D. DNS

Correct Answer: C. NTP

Explanation:
Network Time Protocol (NTP) synchronizes clocks on network devices to a central time source.

23. Which type of IPv6 address is equivalent to IPv4’s public address?

A. Link-local
B. Unique local
C. Global unicast
D. Multicast

Correct Answer: C. Global unicast

Explanation:
Global unicast IPv6 addresses are routable on the Internet, similar to public IPv4 addresses.

24. Which dynamic routing protocol uses cost as its metric and is link-state?

A. RIP
B. EIGRP
C. BGP
D. OSPF

Correct Answer: D. OSPF

Explanation:
OSPF (Open Shortest Path First) is a link-state protocol that uses cost, typically based on bandwidth.

25. Which command saves the current running configuration to NVRAM?

A. copy run start
B. save config
C. write memory
D. copy running-config startup-config

Correct Answer: D. copy running-config startup-config

Explanation:
This command saves the running configuration so it persists after a reboot.

26. What is a characteristic of half-duplex communication?

A. Transmits in both directions simultaneously
B. Slower than full duplex
C. Uses multiple cables
D. Prevents collisions

Correct Answer: B. Slower than full duplex

Explanation:
Half-duplex allows transmission in both directions, but not at the same time, which may cause collisions and reduce speed.

27. Which protocol supports unequal-cost load balancing?

A. RIP
B. OSPF
C. BGP
D. EIGRP

Correct Answer: D. EIGRP

Explanation:
EIGRP supports unequal-cost load balancing using the variance command to distribute traffic across multiple paths.

28. Which mode is used to configure VLANs on a Cisco switch?

A. User EXEC mode
B. Global configuration mode
C. VLAN configuration mode
D. Interface configuration mode

Correct Answer: C. VLAN configuration mode

Explanation:
VLANs are created using vlan [id] in VLAN configuration mode under global configuration.

29. What is the purpose of a trunk port on a switch?

A. Connects two end-user devices
B. Tags VLAN traffic
C. Blocks unnecessary traffic
D. Assigns default VLANs

Correct Answer: B. Tags VLAN traffic

Explanation:
Trunk ports carry multiple VLANs and use tagging (e.g., IEEE 802.1Q) to distinguish traffic.

30. Which field in an Ethernet frame is used to identify the receiving host?

A. Source MAC
B. Destination MAC
C. IP address
D. EtherType

Correct Answer: B. Destination MAC

Explanation:
The destination MAC address ensures the frame reaches the correct host on a LAN segment.

31. What type of address is FF02::1 in IPv6?

A. Global unicast
B. Anycast
C. Link-local
D. Multicast

Correct Answer: D. Multicast

Explanation:
FF02::1 is an IPv6 multicast address that targets all nodes on the local link. Multicast in IPv6 begins with FF00::/8.

32. Which of the following describes a trunk port on a switch?

A. Connects end devices
B. Can only carry traffic for one VLAN
C. Carries multiple VLANs
D. Blocks BPDU traffic

Correct Answer: C. Carries multiple VLANs

Explanation:
A trunk port is configured to carry traffic for multiple VLANs across switches, using tagging protocols like IEEE 802.1Q.

33. What does the switchport mode access command do?

A. Enables a trunk port
B. Assigns a port to all VLANs
C. Forces a port into access mode
D. Creates a default gateway

Correct Answer: C. Forces a port into access mode

Explanation:
switchport mode access configures a port as an access port, allowing it to carry traffic for only one VLAN.

34. What does the TTL field in an IP packet help prevent?

A. Unauthorized access
B. Packet duplication
C. Routing loops
D. Fragmentation

Correct Answer: C. Routing loops

Explanation:
The TTL (Time to Live) field is decremented by one at each router. When it hits zero, the packet is discarded, preventing infinite loops.

35. What is the first step in the DHCP process?

A. DHCP Offer
B. DHCP Discover
C. DHCP Request
D. DHCP Acknowledge

Correct Answer: B. DHCP Discover

Explanation:
The DHCP process begins with the client broadcasting a DHCP Discover message to find available DHCP servers.

36. What is the purpose of the ARP protocol?

A. To find domain names
B. To resolve IP to MAC addresses
C. To provide encryption
D. To update routing tables

Correct Answer: B. To resolve IP to MAC addresses

Explanation:
Address Resolution Protocol (ARP) maps an IP address to a MAC address on a local network, essential for Ethernet communication.

37. Which IPv4 address is reserved for loopback testing?

A. 0.0.0.0
B. 255.255.255.255
C. 127.0.0.1
D. 169.254.0.1

Correct Answer: C. 127.0.0.1

Explanation:
The loopback address (127.0.0.1) is used for testing the internal network stack of a device. It never leaves the device.

38. What Cisco IOS command enables a router interface?

A. activate
B. ip enable
C. interface up
D. no shutdown

Correct Answer: D. no shutdown

Explanation:
Cisco interfaces are administratively down by default. The no shutdown command brings them up.

39. What is the purpose of ACLs (Access Control Lists) on routers?

A. Assign IP addresses
B. Encrypt traffic
C. Filter traffic based on rules
D. Perform NAT translation

Correct Answer: C. Filter traffic based on rules

Explanation:
ACLs are used to permit or deny traffic based on IP addresses, ports, and protocols, thereby improving security and control.

40. What is the primary difference between TCP and UDP?

A. UDP is encrypted
B. TCP provides error correction and connection management
C. TCP is faster than UDP
D. UDP guarantees delivery

Correct Answer: B. TCP provides error correction and connection management

Explanation:
TCP is a connection-oriented protocol that ensures reliability via acknowledgments, sequencing, and retransmissions. UDP is connectionless and does not guarantee delivery.

41. What is the subnet mask for a /26 network?

A. 255.255.255.128
B. 255.255.255.192
C. 255.255.255.224
D. 255.255.255.240

Answer: B. 255.255.255.192
Explanation:
A /26 prefix means 26 bits are reserved for the network, leaving 6 bits for hosts. This corresponds to a subnet mask of 255.255.255.192.

42. What routing protocol is considered a hybrid protocol?

A. RIP
B. EIGRP
C. OSPF
D. BGP

Answer: B. EIGRP
Explanation:
EIGRP (Enhanced Interior Gateway Routing Protocol) combines features of both distance-vector and link-state protocols, making it a hybrid.

43. Which command is used to view the routing table on a Cisco router?

A. show ip interface brief
B. show route
C. show ip route
D. show interfaces

Answer: C. show ip route
Explanation:
The show ip route command displays the current IP routing table on a Cisco device.

44. What does the 802.1Q protocol do?

A. Encrypts VLAN traffic
B. Assigns MAC addresses
C. Tags frames with VLAN ID
D. Authenticates devices

Answer: C. Tags frames with VLAN ID
Explanation:
802.1Q is the standard VLAN trunking protocol that tags Ethernet frames with VLAN identifiers.

45. Which device operates only at Layer 2 of the OSI model?

A. Router
B. Switch
C. Firewall
D. Repeater

Answer: B. Switch
Explanation:
A basic switch operates at Layer 2 (Data Link), forwarding traffic based on MAC addresses.

46. What does NAT accomplish in a network?

A. Provides encryption
B. Blocks external traffic
C. Maps private IPs to public IPs
D. Assigns MAC addresses

Answer: C. Maps private IPs to public IPs
Explanation:
Network Address Translation (NAT) translates private IP addresses to a public IP to allow internet access.

47. What is the administrative distance of OSPF?

A. 100
B. 110
C. 90
D. 120

Answer: B. 110
Explanation:
OSPF has an administrative distance of 110, used to determine route preference.

48. What layer of the OSI model is responsible for encryption and compression?

A. Network
B. Session
C. Presentation
D. Transport

Answer: C. Presentation
Explanation:
The Presentation layer (Layer 6) handles data format translation, encryption, and compression.

49. What is the primary role of a default gateway?

A. Translate domain names
B. Connect LANs together
C. Route traffic to remote networks
D. Provide dynamic IPs

Answer: C. Route traffic to remote networks
Explanation:
The default gateway routes traffic from a local network to devices in other networks or the internet.

50. Which protocol is used to monitor and manage network devices?

A. FTP
B. SNMP
C. SMTP
D. NTP

Answer: B. SNMP
Explanation:
Simple Network Management Protocol (SNMP) is used to monitor and manage network hardware.

51. Which layer of the OSI model does a router operate in?

A. Layer 2
B. Layer 3
C. Layer 4
D. Layer 5

Answer: B. Layer 3
Explanation:
Routers operate at Layer 3 (Network), making decisions based on IP addresses.

52. What is the range of well-known TCP/UDP ports?

A. 0–1023
B. 1024–49151
C. 49152–65535
D. 0–65535

Answer: A. 0–1023
Explanation:
Ports 0–1023 are known as well-known ports and are assigned to common protocols like HTTP (80), FTP (21), etc.

53. What command is used to save the running configuration to NVRAM?

A. write mem
B. save
C. copy running-config startup-config
D. store-config

Answer: C. copy running-config startup-config
Explanation:
This command saves the current configuration to startup-config in NVRAM to persist after reboot.

54. Which protocol helps prevent switching loops?

A. VTP
B. STP
C. RIP
D. BGP

Answer: B. STP
Explanation:
The Spanning Tree Protocol (STP) prevents Layer 2 switching loops by blocking redundant paths.

55. What address type is 169.254.x.x?

A. Loopback
B. Multicast
C. APIPA
D. Broadcast

Answer: C. APIPA
Explanation:
Automatic Private IP Addressing (APIPA) assigns an IP in the 169.254.0.0/16 range when DHCP fails.

56. What is the function of CDP in Cisco networks?

A. Manages VLANs
B. Discovers neighboring Cisco devices
C. Authenticates users
D. Assigns IP addresses

Answer: B. Discovers neighboring Cisco devices
Explanation:
Cisco Discovery Protocol (CDP) enables Cisco devices to share and discover hardware info on directly connected links.

57. Which command is used to enable RIP routing?

A. enable rip
B. router rip
C. rip enable
D. ip rip routing

Answer: B. router rip
Explanation:
To configure RIP routing, use the router rip command in global configuration mode.

58. How many usable hosts are there in a /30 subnet?

A. 2
B. 4
C. 6
D. 14

Answer: A. 2
Explanation:
A /30 subnet provides 4 IPs total: 2 usable, 1 network address, and 1 broadcast address.

59. What protocol is used by ping?

A. UDP
B. ICMP
C. TCP
D. SNMP

Answer: B. ICMP
Explanation:
Ping uses Internet Control Message Protocol (ICMP) to send echo requests and receive echo replies.

60. Which command displays interface status in a Cisco device?

A. show interface
B. show ip
C. show interface status
D. show ip route

Answer: A. show interface
Explanation:
The show interface command shows detailed info about interface status, errors, and bandwidth usage.

61. What is the maximum length of a UTP Ethernet cable per the standard?

A. 50 meters
B. 100 meters
C. 185 meters
D. 500 meters

Answer: B. 100 meters
Explanation:
UTP (Unshielded Twisted Pair) Ethernet cables should not exceed 100 meters for reliable signal integrity.

62. What protocol does a router use to determine the MAC address of a next-hop IP?

A. DNS
B. ARP
C. DHCP
D. NTP

Answer: B. ARP
Explanation:
Routers use ARP (Address Resolution Protocol) to map an IP address to a MAC address on the same subnet.

63. Which routing protocol is link-state?

A. EIGRP
B. RIP
C. OSPF
D. BGP

Answer: C. OSPF
Explanation:
Open Shortest Path First (OSPF) is a link-state protocol, which maintains a complete topology map.

64. What feature must be enabled for inter-VLAN communication?

A. NAT
B. Trunking
C. Routing
D. DHCP

Answer: C. Routing
Explanation:
For inter-VLAN communication, routing between VLANs must be enabled via a router or Layer 3 switch.

65. What is the command to configure an IP address on a Cisco router interface?

A. ip assign
B. interface ip
C. ip address 192.168.1.1 255.255.255.0
D. set ip address

Answer: C. ip address 192.168.1.1 255.255.255.0
Explanation:
Use ip address [IP] [Subnet Mask] in interface configuration mode to assign an IP.

66. What is the binary equivalent of the decimal number 192?

A. 10101010
B. 11000000
C. 10000001
D. 11111111

Answer: B. 11000000
Explanation:
The decimal number 192 converts to binary as 11000000.

67. What command displays VLAN information on a Cisco switch?

A. show vlan
B. show vlan brief
C. display vlan
D. vlan status

Answer: B. show vlan brief
Explanation:
The show vlan brief command displays VLAN IDs, names, and associated interfaces.

68. What is a benefit of using dynamic routing protocols over static routing?

A. Increased CPU usage
B. Manual route updates
C. Automatically adapts to topology changes
D. Requires no configuration

Answer: C. Automatically adapts to topology changes
Explanation:
Dynamic routing adjusts routes automatically when the network changes, which static routing does not.

69. What is the role of a DNS server?

A. Provides IP addresses to devices
B. Maps domain names to IP addresses
C. Encrypts web traffic
D. Routes internal emails

Answer: B. Maps domain names to IP addresses
Explanation:
DNS (Domain Name System) translates human-friendly domain names into IP addresses.

70. Which Cisco command enables an interface from shutdown state?

A. enable interface
B. activate
C. no shutdown
D. boot up

Answer: C. no shutdown
Explanation:
By default, interfaces may be administratively down. Use no shutdown to enable them.

71. Which IPv6 address type is equivalent to the IPv4 broadcast address?

A. Anycast
B. Multicast
C. Unicast
D. There is no IPv6 broadcast address

Answer: D. There is no IPv6 broadcast address
Explanation:
IPv6 does not use broadcast addressing. Instead, multicast and anycast are used for group communication.

72. What is the maximum number of hosts in a Class C network?

A. 254
B. 256
C. 512
D. 1024

Answer: A. 254
Explanation:
Class C networks have a default subnet mask of 255.255.255.0, allowing for 256 IP addresses; 254 usable hosts (excluding network and broadcast addresses).

73. Which command disables CDP on a Cisco interface?

A. no cdp enable
B. no cdp run
C. disable cdp
D. cdp off

Answer: A. no cdp enable
Explanation:
CDP can be disabled on a per-interface basis using no cdp enable.

74. What is the function of VTP?

A. Transmit VLAN info across switches
B. Encrypt VLAN data
C. Assign IP addresses dynamically
D. Prevent routing loops

Answer: A. Transmit VLAN info across switches
Explanation:
VLAN Trunking Protocol (VTP) manages and propagates VLAN configurations across Cisco switches in a domain.

75. Which of these is a classful routing protocol?

A. OSPF
B. EIGRP
C. RIP version 1
D. RIP version 2

Answer: C. RIP version 1
Explanation:
RIP v1 does not support subnet masks in routing updates and is classful.

76. What does the “show interfaces trunk” command display?

A. VLANs allowed on trunk ports
B. Status of trunk interfaces
C. IP addresses assigned to interfaces
D. Routing table information

Answer: B. Status of trunk interfaces
Explanation:
It shows trunk interface status, VLANs allowed, and trunking protocol info.

77. Which WAN technology uses labels to make forwarding decisions?

A. MPLS
B. Frame Relay
C. PPP
D. ATM

Answer: A. MPLS
Explanation:
Multiprotocol Label Switching (MPLS) uses labels to route packets efficiently through a WAN.

78. What is the function of a CSU/DSU device?

A. Routes packets between LANs
B. Converts digital signals for WAN connections
C. Provides DHCP services
D. Manages VLANs

Answer: B. Converts digital signals for WAN connections
Explanation:
CSU/DSU converts a digital data signal from a router into a format compatible with the WAN service provider.

79. Which protocol is used to negotiate link parameters automatically on Ethernet?

A. ARP
B. CDP
C. DTP
D. Auto-MDIX

Answer: D. Auto-MDIX
Explanation:
Auto-MDIX allows automatic crossover or straight-through cable detection and configuration on Ethernet ports.

80. What does the acronym VLAN stand for?

A. Virtual Local Area Network
B. Variable Local Access Network
C. Virtual Link Access Network
D. Verified LAN Access Node

Answer: A. Virtual Local Area Network
Explanation:
VLAN logically segments networks into smaller broadcast domains.

81. What does the command switchport mode access do?

A. Puts the port into trunk mode
B. Allows the port to carry multiple VLANs
C. Configures the port as an access port for a single VLAN
D. Disables the port

Answer: C. Configures the port as an access port for a single VLAN
Explanation:
This command sets the port to carry traffic for only one VLAN (non-trunk).

82. What is the default administrative distance of EIGRP?

A. 90
B. 110
C. 120
D. 100

Answer: A. 90
Explanation:
EIGRP’s administrative distance is 90, indicating its trustworthiness relative to other protocols.

83. Which of the following is a valid private IPv4 address?

A. 8.8.8.8
B. 172.16.0.1
C. 192.0.2.1
D. 198.51.100.1

Answer: B. 172.16.0.1
Explanation:
172.16.0.0 to 172.31.255.255 is part of private IP space.

84. What does the command ip helper-address do?

A. Enables DHCP server on the router
B. Forwards DHCP requests to a DHCP server on another subnet
C. Displays DHCP leases
D. Assigns static IP to hosts

Answer: B. Forwards DHCP requests to a DHCP server on another subnet
Explanation:
ip helper-address forwards UDP broadcasts like DHCP from clients to a DHCP server in a different subnet.

85. What device connects multiple networks and filters traffic based on IP addresses?

A. Switch
B. Router
C. Hub
D. Bridge

Answer: B. Router
Explanation:
Routers connect networks and make decisions using IP addresses.

86. What is the primary purpose of a Layer 3 switch?

A. Forward frames based on MAC addresses
B. Perform routing between VLANs
C. Broadcast packets to all ports
D. Encrypt data

Answer: B. Perform routing between VLANs
Explanation:
Layer 3 switches can perform routing functions in addition to switching.

87. What command enables OSPF on a Cisco router?

A. router ospf 1
B. enable ospf
C. ip ospf start
D. ospf router

Answer: A. router ospf 1
Explanation:
You enter OSPF configuration mode with router ospf [process-id].

88. What is the default subnet mask for a Class B IP address?

A. 255.255.0.0
B. 255.0.0.0
C. 255.255.255.0
D. 255.255.255.255

Answer: A. 255.255.0.0
Explanation:
Class B default subnet mask is 255.255.0.0.

89. What does ACL stand for?

A. Access Control List
B. Advanced Connection Layer
C. Access Control Link
D. Automated Control List

Answer: A. Access Control List
Explanation:
ACLs filter traffic and control access based on rules.

90. What is the purpose of the command show ip protocols?

A. Displays the routing table
B. Shows details of routing protocols running on the router
C. Displays IP interface configurations
D. Shows active IP sessions

Answer: B. Shows details of routing protocols running on the router
Explanation:
Displays protocol parameters like timers, networks, and neighbors.

91. What is a characteristic of the TCP protocol?

A. Connectionless
B. Unreliable
C. Connection-oriented
D. Used for streaming only

Answer: C. Connection-oriented
Explanation:
TCP establishes a reliable connection and ensures ordered delivery of packets.

92. What is the purpose of the switchport trunk encapsulation dot1q command?

A. Configures port security
B. Sets the trunking protocol to IEEE 802.1Q
C. Enables DHCP snooping
D. Converts the port to an access port

Answer: B. Sets the trunking protocol to IEEE 802.1Q
Explanation:
Configures a trunk port to use 802.1Q encapsulation for VLAN tagging.

93. Which routing protocol is primarily used on the Internet?

A. OSPF
B. EIGRP
C. BGP
D. RIP

Answer: C. BGP
Explanation:
Border Gateway Protocol (BGP) is used for routing between autonomous systems on the Internet.

94. What does a port security violation cause by default on a Cisco switch?

A. Shuts down the port
B. Drops unauthorized traffic and logs the violation
C. Sends an email alert
D. Reboots the switch

Answer: B. Drops unauthorized traffic and logs the violation
Explanation:
By default, port security drops unauthorized frames and generates a log; it does not shut down the port unless configured to do so.

95. What is the purpose of the command debug ip packet?

A. Enables debugging of IP packet forwarding on a router
B. Displays the IP routing table
C. Shows packet captures
D. Resets the IP stack

Answer: A. Enables debugging of IP packet forwarding on a router
Explanation:
This command shows detailed debugging info about IP packets processed by the router.

96. Which of these is NOT a valid IPv6 address?

A. 2001:0db8::1
B. ::1
C. 192.168.1.1
D. fe80::

Answer: C. 192.168.1.1
Explanation:
192.168.1.1 is an IPv4 address, not IPv6.

97. What is the maximum transmission unit (MTU) size for Ethernet?

A. 1500 bytes
B. 1400 bytes
C. 1200 bytes
D. 1600 bytes

Answer: A. 1500 bytes
Explanation:
Standard Ethernet MTU is 1500 bytes.

98. Which command will show you the MAC address table on a Cisco switch?

A. show mac address-table
B. show mac-table
C. show interfaces mac
D. show switch mac

Answer: A. show mac address-table
Explanation:
Displays learned MAC addresses and their associated ports.

99. What is the default VLAN on a Cisco switch?

A. VLAN 1
B. VLAN 10
C. VLAN 100
D. VLAN 0

Answer: A. VLAN 1
Explanation:
VLAN 1 is the default VLAN on Cisco switches.

100. What does the command ip route 0.0.0.0 0.0.0.0 192.168.1.1 configure?

A. Static default route
B. Dynamic route
C. Host route
D. Routing protocol

Answer: A. Static default route
Explanation:
This sets a default route, directing all traffic not in the routing table to 192.168.1.1.

101. Which of the following protocols is responsible for resolving IPv4 addresses to MAC addresses?

A. ARP
B. DNS
C. ICMP
D. DHCP

Answer: A. ARP
Explanation:
Address Resolution Protocol (ARP) maps IPv4 addresses to their corresponding MAC addresses within a local network.

102. What is the purpose of the show cdp neighbors command?

A. Displays directly connected Cisco devices
B. Lists all devices in the network
C. Shows IP routing table
D. Displays VLAN information

Answer: A. Displays directly connected Cisco devices
Explanation:
CDP (Cisco Discovery Protocol) helps identify directly connected Cisco devices and their interfaces.

103. In OSPF, what does the acronym DR stand for?

A. Dynamic Router
B. Designated Router
C. Data Router
D. Default Router

Answer: B. Designated Router
Explanation:
DR is elected on broadcast networks to reduce routing update traffic.

104. What type of address is FE80::/10 in IPv6?

A. Global unicast
B. Link-local
C. Multicast
D. Loopback

Answer: B. Link-local
Explanation:
FE80::/10 addresses are used for communication within the local network segment.

105. What command would you use to enable RIP routing on a router?

A. router rip
B. enable rip
C. ip routing rip
D. router enable rip

Answer: A. router rip
Explanation:
This command enters RIP routing configuration mode.

106. Which Ethernet frame type does Cisco switches use by default for trunking?

A. ISL
B. 802.1Q
C. SNAP
D. HDLC

Answer: B. 802.1Q
Explanation:
802.1Q is the IEEE standard for VLAN tagging on trunks, supported by all Cisco switches.

107. What is the main advantage of using OSPF over RIP?

A. Simpler configuration
B. Supports variable-length subnet masking (VLSM) and faster convergence
C. Works on non-IP protocols
D. Requires less CPU resources

Answer: B. Supports variable-length subnet masking (VLSM) and faster convergence
Explanation:
OSPF supports CIDR and converges faster than RIP.

108. Which command displays the current spanning tree status on a Cisco switch?

A. show spanning-tree
B. show stp
C. show spanning
D. show tree

Answer: A. show spanning-tree
Explanation:
Displays detailed information about the Spanning Tree Protocol operation on the switch.

109. What is the default administrative distance of OSPF?

A. 90
B. 100
C. 110
D. 120

Answer: C. 110
Explanation:
OSPF uses an administrative distance of 110.

110. What is the primary purpose of NAT (Network Address Translation)?

A. Encrypt data packets
B. Translate private IP addresses to public IP addresses
C. Route packets between VLANs
D. Provide DHCP services

Answer: B. Translate private IP addresses to public IP addresses
Explanation:
NAT allows devices on a private network to communicate with external networks using a public IP.

111. Which of the following is NOT a Layer 2 protocol?

A. ARP
B. CDP
C. IP
D. STP

Answer: C. IP
Explanation:
IP is a Layer 3 protocol, while ARP, CDP, and STP operate at Layer 2.

112. What is the maximum number of hosts on a subnet with mask 255.255.255.224?

A. 30
B. 32
C. 62
D. 64

Answer: A. 30
Explanation:
Subnet mask 255.255.255.224 (/27) provides 32 IP addresses, 30 usable hosts (subtracting network and broadcast).

113. Which protocol provides dynamic IP addresses to hosts?

A. DHCP
B. DNS
C. FTP
D. SMTP

Answer: A. DHCP
Explanation:
Dynamic Host Configuration Protocol (DHCP) assigns IP addresses dynamically to clients.

114. What is the default hello interval for OSPF on broadcast networks?

A. 10 seconds
B. 30 seconds
C. 60 seconds
D. 90 seconds

Answer: A. 10 seconds
Explanation:
OSPF routers send hello packets every 10 seconds on broadcast and point-to-point networks.

115. What command will show the running configuration of a Cisco router?

A. show running-config
B. show start-config
C. show config
D. show running

Answer: A. show running-config
Explanation:
Displays the current active configuration on the device.

116. What is the purpose of the switchport nonegotiate command?

A. Disables DTP negotiation on the port
B. Enables negotiation of VLANs
C. Enables trunking negotiation
D. Disables VLAN tagging

Answer: A. Disables DTP negotiation on the port
Explanation:
Stops the port from negotiating trunking using DTP.

117. What is the IPv6 loopback address?

A. ::1
B. 127.0.0.1
C. FE80::1
D. ::

Answer: A. ::1
Explanation:
::1 is the IPv6 equivalent of IPv4 127.0.0.1 (loopback address).

118. What does the acronym SSH stand for?

A. Secure Shell
B. Secure Socket Handler
C. Simple Shell Host
D. Secure Server Host

Answer: A. Secure Shell
Explanation:
SSH provides secure encrypted communication to manage network devices.

119. What is the main function of the traceroute command?

A. Displays the path packets take to a destination
B. Tests the reachability of a device
C. Displays the routing table
D. Shows interface statistics

Answer: A. Displays the path packets take to a destination
Explanation:
traceroute shows each hop from source to destination.

120. What Layer of the OSI model is responsible for logical addressing?

A. Data Link
B. Network
C. Transport
D. Physical

Answer: B. Network
Explanation:
Logical addressing (IP addressing) occurs at the Network Layer.

121. Which command will configure a router interface with IP address 192.168.1.1/24?

A. ip address 192.168.1.1 255.255.255.0
B. ip address 192.168.1.1 24
C. interface ip 192.168.1.1 255.255.255.0
D. set ip 192.168.1.1 255.255.255.0

Answer: A. ip address 192.168.1.1 255.255.255.0
Explanation:
This is the correct syntax to assign an IP address and subnet mask to an interface.

122. What does the command no shutdown do on a Cisco router interface?

A. Enables the interface
B. Disables the interface
C. Shuts down the router
D. Resets the interface

Answer: A. Enables the interface
Explanation:
Interfaces are shut down by default and must be enabled with no shutdown.

123. Which command is used to save the running configuration to startup configuration?

A. copy running-config startup-config
B. save config
C. write memory
D. Both A and C

Answer: D. Both A and C
Explanation:
Both commands save the current running configuration to NVRAM.

124. Which routing protocol supports unequal cost load balancing?

A. RIP
B. OSPF
C. EIGRP
D. BGP

Answer: C. EIGRP
Explanation:
EIGRP supports variance for unequal-cost load balancing.

125. What is the default port for SSH?

A. 22
B. 23
C. 21
D. 80

Answer: A. 22
Explanation:
SSH runs on TCP port 22.

126. Which command displays all active TCP connections on a router?

A. show tcp brief
B. show tcp connections
C. show ip sockets
D. show ip tcp brief

Answer: D. show ip tcp brief
Explanation:
Displays active TCP connections in a summarized form.

127. Which protocol provides time synchronization in networks?

A. NTP
B. FTP
C. SMTP
D. DNS

Answer: A. NTP
Explanation:
Network Time Protocol (NTP) synchronizes clocks across devices.

128. Which protocol is used to transfer files securely?

A. FTP
B. SFTP
C. TFTP
D. HTTP

Answer: B. SFTP
Explanation:
SFTP uses SSH for secure file transfer.

129. Which command can disable IPv6 on a Cisco interface?

A. no ipv6 enable
B. disable ipv6
C. ipv6 off
D. no ipv6 address

Answer: A. no ipv6 enable
Explanation:
This disables IPv6 processing on the interface.

130. What does the acronym VPN stand for?

A. Virtual Private Network
B. Virtual Public Network
C. Verified Private Node
D. Virtual Protected Network

Answer: A. Virtual Private Network
Explanation:
VPNs create secure encrypted tunnels over public networks.

131. What is the purpose of a VLAN in a network?

A. To increase broadcast domains
B. To create separate collision domains
C. To segment a network logically regardless of physical location
D. To replace routers

Answer: C. To segment a network logically regardless of physical location
Explanation:
VLANs (Virtual Local Area Networks) logically segment a network into different broadcast domains, which enhances security and reduces broadcast traffic, without changing the physical wiring.

132. Which command enables OSPF on a router for network 192.168.10.0/24?

A. router ospf 1 then network 192.168.10.0 0.0.0.255 area 0
B. router ospf 1 then network 192.168.10.0 255.255.255.0 area 0
C. router ospf 0 then network 192.168.10.0 0.0.0.255
D. router ospf 0 then network 192.168.10.0 255.255.255.0

Answer: A. router ospf 1 then network 192.168.10.0 0.0.0.255 area 0
Explanation:
OSPF network statements use wildcard masks (inverse subnet masks). The correct wildcard mask for a /24 subnet (255.255.255.0) is 0.0.0.255.

133. Which switching method stores the entire frame in memory before forwarding?

A. Cut-through
B. Fragment-free
C. Store-and-forward
D. Fast-forward

Answer: C. Store-and-forward
Explanation:
Store-and-forward switches buffer the entire frame and check for errors before forwarding, improving reliability but with higher latency.

134. What is the main difference between TCP and UDP?

A. TCP is connectionless; UDP is connection-oriented
B. TCP guarantees delivery and order of packets; UDP does not
C. TCP is faster than UDP
D. TCP uses ports; UDP does not

Answer: B. TCP guarantees delivery and order of packets; UDP does not
Explanation:
TCP is connection-oriented, providing reliable, ordered delivery, while UDP is connectionless and does not guarantee packet delivery or order.

135. What is a reason to use a static route instead of a dynamic routing protocol?

A. When the network is large and changes frequently
B. When routing decisions need to be automatic
C. When routes are simple and unlikely to change
D. When faster convergence is required

Answer: C. When routes are simple and unlikely to change
Explanation:
Static routes are manually configured and are ideal for small, stable networks without frequent changes.

136. In Spanning Tree Protocol, what is the purpose of the Root Bridge?

A. It serves as the central point of reference for path calculations
B. It blocks redundant links
C. It manages IP addressing
D. It assigns VLAN IDs

Answer: A. It serves as the central point of reference for path calculations
Explanation:
The Root Bridge is the logical center of the network, and all path calculations are based on it to prevent loops.

137. What type of IPv6 address is FF02::1?

A. Global unicast
B. Link-local unicast
C. Multicast
D. Anycast

Answer: C. Multicast
Explanation:
FF02::1 is the IPv6 multicast address for all nodes on the local link.

138. Which routing protocol is classified as a distance-vector protocol?

A. OSPF
B. EIGRP
C. RIP
D. IS-IS

Answer: C. RIP
Explanation:
RIP is a classic distance-vector routing protocol, relying on hop count and periodic updates.

139. Which command shows the interfaces and their IP addresses on a Cisco router?

A. show interfaces
B. show ip interface brief
C. show running-config
D. show ip route

Answer: B. show ip interface brief
Explanation:
This command displays a concise summary of interfaces, IP addresses, and their status.

140. Which protocol does ICMP work with?

A. TCP
B. UDP
C. IP
D. FTP

Answer: C. IP
Explanation:
ICMP (Internet Control Message Protocol) is a network layer protocol used with IP for diagnostic and error messages.

141. What is the default VLAN on Cisco switches?

A. VLAN 1
B. VLAN 10
C. VLAN 100
D. VLAN 0

Answer: A. VLAN 1
Explanation:
VLAN 1 is the default VLAN for management and all switch ports by default.

142. What is the maximum transmission unit (MTU) size for Ethernet frames?

A. 1280 bytes
B. 1500 bytes
C. 9000 bytes
D. 576 bytes

Answer: B. 1500 bytes
Explanation:
The standard Ethernet MTU is 1500 bytes, which is the largest payload size of the frame.

143. What type of address is used for one-to-one communication in networking?

A. Broadcast address
B. Multicast address
C. Unicast address
D. Anycast address

Answer: C. Unicast address
Explanation:
Unicast addresses identify a single unique device on the network.

144. What is the default subnet mask for a Class C IP address?

A. 255.0.0.0
B. 255.255.0.0
C. 255.255.255.0
D. 255.255.255.255

Answer: C. 255.255.255.0
Explanation:
Class C networks have a default subnet mask of 255.255.255.0, allowing for up to 254 hosts.

145. Which command disables CDP on an interface?

A. no cdp enable
B. shutdown cdp
C. cdp disable
D. no cdp run

Answer: A. no cdp enable
Explanation:
This command disables CDP on a specific interface; no cdp run disables globally.

146. What command can verify the VLANs configured on a switch?

A. show vlan brief
B. show vlan
C. Both A and B
D. show interfaces vlan

Answer: C. Both A and B
Explanation:
Both commands display VLAN information; show vlan brief provides a summary.

147. Which type of cable is used to connect two switches directly?

A. Straight-through cable
B. Crossover cable
C. Rollover cable
D. Coaxial cable

Answer: B. Crossover cable
Explanation:
Crossover cables connect similar devices like switch-to-switch or router-to-router.

148. What does the acronym DHCP stand for?

A. Dynamic Host Control Protocol
B. Dynamic Host Configuration Protocol
C. Dynamic Hypertext Configuration Protocol
D. Dynamic Host Communication Protocol

Answer: B. Dynamic Host Configuration Protocol
Explanation:
DHCP automatically assigns IP configuration parameters to hosts.

149. What is the maximum number of hosts possible on a /29 subnet?

A. 4
B. 6
C. 8
D. 14

Answer: B. 6
Explanation:
A /29 subnet (255.255.255.248) provides 8 IP addresses; 6 are usable (subtract network and broadcast).

150. Which command enables SSH on a Cisco router?

A. ip ssh version 2
B. crypto key generate rsa
C. Both A and B
D. enable ssh

Answer: C. Both A and B
Explanation:
Generate RSA keys first; then enable SSH version 2 for secure remote management.

151. What does the acronym MTU stand for?

A. Maximum Transmission Unit
B. Minimum Transfer Unit
C. Maximum Transfer Usage
D. Minimum Transmission Usage

Answer: A. Maximum Transmission Unit
Explanation:
MTU defines the largest packet size that can be transmitted.

152. What is the function of a default gateway?

A. Connects different VLANs
B. Routes traffic from a local network to external networks
C. Provides IP addresses dynamically
D. Filters broadcast traffic

Answer: B. Routes traffic from a local network to external networks
Explanation:
The default gateway acts as the exit point for traffic destined outside the local subnet.

153. What does the command show ip protocols display?

A. Active routing protocols and their settings
B. IP addresses on the router
C. DHCP leases
D. DNS server information

Answer: A. Active routing protocols and their settings
Explanation:
It shows configured routing protocols, timers, and neighbors.

154. Which protocol is used to automatically assign IP addresses to devices?

A. FTP
B. SMTP
C. DHCP
D. DNS

Answer: C. DHCP
Explanation:
DHCP automates IP configuration.

155. What is the command to create a standard access list that permits the network 192.168.10.0/24?

A. access-list 10 permit 192.168.10.0 0.0.0.255
B. access-list 10 permit 192.168.10.0 255.255.255.0
C. access-list 10 permit 192.168.10.0
D. ip access-list standard 10 permit 192.168.10.0

Answer: A. access-list 10 permit 192.168.10.0 0.0.0.255
Explanation:
Access lists use wildcard masks, so 0.0.0.255 matches a /24 subnet.

156. Which protocol is primarily used for secure remote login?

A. Telnet
B. FTP
C. SSH
D. HTTP

Answer: C. SSH
Explanation:
SSH encrypts remote management sessions, unlike Telnet.

157. What command is used to display the MAC address table on a switch?

A. show mac address-table
B. show arp
C. show mac
D. show interfaces

Answer: A. show mac address-table
Explanation:
Displays learned MAC addresses and associated ports.

158. What does the ping command test?

A. Route path to a destination
B. Network connectivity between devices
C. Port status
D. DNS resolution

Answer: B. Network connectivity between devices
Explanation:
ping sends ICMP Echo Requests to test reachability.

159. What is the function of a switch in a network?

A. Routes packets between networks
B. Filters and forwards frames within the same network
C. Provides IP addresses
D. Converts analog signals to digital

Answer: B. Filters and forwards frames within the same network
Explanation:
Switches operate at Layer 2 to forward frames based on MAC addresses.

160. Which Cisco IOS mode allows you to configure interface parameters?

A. User EXEC mode
B. Privileged EXEC mode
C. Global configuration mode
D. Interface configuration mode

Answer: D. Interface configuration mode
Explanation:
To configure interfaces, you enter interface configuration mode from global config mode.

161. What command is used to save the running configuration to the startup configuration on a Cisco device?

A. copy startup-config running-config
B. write memory
C. copy running-config startup-config
D. save config

Answer: C. copy running-config startup-config
Explanation:
This command saves the current running configuration to NVRAM, so it loads on reboot.

162. Which layer of the OSI model is responsible for logical addressing?

A. Data Link
B. Network
C. Transport
D. Session

Answer: B. Network
Explanation:
The Network layer manages logical addressing (e.g., IP addresses) and routing.

163. Which of the following is a link-state routing protocol?

A. RIP
B. EIGRP
C. OSPF
D. BGP

Answer: C. OSPF
Explanation:
OSPF is a link-state protocol that maintains a map of the network topology.

164. What is the default administrative distance (AD) of OSPF?

A. 90
B. 100
C. 110
D. 120

Answer: C. 110
Explanation:
OSPF has a default AD of 110, which determines its trustworthiness relative to other routing protocols.

165. Which layer of the OSI model handles error detection and frame sequencing?

A. Physical
B. Data Link
C. Network
D. Transport

Answer: B. Data Link
Explanation:
The Data Link layer provides error detection and frames sequencing within the local network.

166. What is the purpose of NAT in a network?

A. To assign IP addresses dynamically
B. To translate private IP addresses to public IP addresses
C. To encrypt data
D. To segment broadcast domains

Answer: B. To translate private IP addresses to public IP addresses
Explanation:
NAT allows devices with private IPs to communicate on the public internet by translating addresses.

167. What is the valid range of VLAN IDs in Cisco switches?

A. 1-1005
B. 1-4094
C. 1006-4094
D. 0-4095

Answer: B. 1-4094
Explanation:
Cisco switches support VLAN IDs from 1 through 4094, though 1002-1005 are reserved for legacy protocols.

168. What is the function of the Cisco IOS command show cdp neighbors?

A. Displays neighboring router IP addresses
B. Displays connected devices discovered via Cisco Discovery Protocol
C. Shows routing table neighbors
D. Shows IP address of all interfaces

Answer: B. Displays connected devices discovered via Cisco Discovery Protocol
Explanation:
CDP helps identify directly connected Cisco devices and their interface info.

169. What is the effect of the command switchport mode trunk on a switch port?

A. Configures the port to carry traffic for multiple VLANs
B. Configures the port to connect only to end devices
C. Disables VLAN tagging on the port
D. Assigns a port to VLAN 1

Answer: A. Configures the port to carry traffic for multiple VLANs
Explanation:
Trunk ports carry traffic from multiple VLANs, tagging frames with VLAN IDs.

170. Which protocol is used for resolving IP addresses to MAC addresses?

A. ARP
B. RARP
C. DNS
D. ICMP

Answer: A. ARP
Explanation:
Address Resolution Protocol (ARP) maps IPv4 addresses to MAC addresses on the local network.

171. Which command will display the router’s current routing table?

A. show ip route
B. show routing
C. show routes
D. show route

Answer: A. show ip route
Explanation:
Displays all known routes, including connected, static, and learned routes.

172. Which wireless security protocol is the most secure?

A. WEP
B. WPA
C. WPA2
D. WPA3

Answer: D. WPA3
Explanation:
WPA3 is the latest and most secure wireless encryption standard.

173. Which protocol is responsible for automatic assignment of IP addresses in IPv6?

A. DHCPv6
B. SLAAC
C. NAT
D. DNS

Answer: B. SLAAC
Explanation:
Stateless Address Autoconfiguration (SLAAC) allows IPv6 devices to assign their own addresses.

174. What is a characteristic of TCP?

A. Connectionless and unreliable
B. Connection-oriented and reliable
C. Uses broadcast to transmit data
D. Does not support flow control

Answer: B. Connection-oriented and reliable
Explanation:
TCP establishes connections and ensures data delivery with sequencing and acknowledgments.

175. What is the maximum number of hosts on a /26 subnet?

A. 62
B. 64
C. 126
D. 254

Answer: A. 62
Explanation:
A /26 subnet mask leaves 6 bits for hosts (2^6=64), subtracting 2 for network and broadcast leaves 62 usable hosts.

176. Which protocol is used for secure file transfers over SSH?

A. FTP
B. TFTP
C. SCP
D. HTTP

Answer: C. SCP
Explanation:
Secure Copy Protocol (SCP) uses SSH for secure file transfer.

177. What is the administrative distance of EIGRP?

A. 90
B. 100
C. 110
D. 120

Answer: A. 90
Explanation:
EIGRP has an administrative distance of 90 by default, making it more trusted than OSPF (110).

178. What type of IPv4 address is 169.254.1.1?

A. Private IP
B. Link-local address
C. Public IP
D. Broadcast address

Answer: B. Link-local address
Explanation:
169.254.x.x addresses are APIPA (Automatic Private IP Addressing), assigned when DHCP fails.

179. Which command is used to view the DHCP bindings on a Cisco router?

A. show ip dhcp binding
B. show dhcp lease
C. show ip dhcp leases
D. show dhcp bindings

Answer: A. show ip dhcp binding
Explanation:
Displays IP-to-MAC address mappings for DHCP clients.

180. What is the effect of issuing no shutdown on an interface?

A. Disables the interface
B. Enables the interface
C. Resets the interface
D. Clears interface statistics

Answer: B. Enables the interface
Explanation:
Interfaces are administratively down by default and need no shutdown to activate.

181. Which protocol is used to send email?

A. SMTP
B. FTP
C. HTTP
D. SNMP

Answer: A. SMTP
Explanation:
Simple Mail Transfer Protocol (SMTP) is used for sending emails.

182. What is the primary function of the Transport layer in the OSI model?

A. Data encryption
B. End-to-end communication and reliability
C. Physical transmission of data
D. Routing of packets

Answer: B. End-to-end communication and reliability
Explanation:
The Transport layer ensures complete data transfer between hosts using protocols like TCP and UDP.

183. What is the purpose of a broadcast address in IPv4?

A. Addressing a single host
B. Addressing all hosts in the subnet
C. Addressing all devices on the internet
D. Multicasting to a group of devices

Answer: B. Addressing all hosts in the subnet
Explanation:
The broadcast address sends packets to all hosts on a subnet.

184. Which Cisco IOS command displays information about interface errors?

A. show interfaces
B. show ip interface
C. show interfaces errors
D. show running-config

Answer: A. show interfaces
Explanation:
Displays detailed interface statistics, including errors, drops, and collisions.

185. What kind of IP address is 255.255.255.255?

A. Network address
B. Broadcast address
C. Default gateway
D. Subnet mask

Answer: B. Broadcast address
Explanation:
255.255.255.255 is the limited broadcast address used to communicate with all hosts on the local network.

186. What is the role of a DHCP relay agent?

A. Assign IP addresses to hosts
B. Forward DHCP requests between clients and servers on different subnets
C. Block unauthorized DHCP servers
D. Assign static IP addresses

Answer: B. Forward DHCP requests between clients and servers on different subnets
Explanation:
DHCP relay agents forward client requests across networks when servers are not local.

187. What is the default metric for RIP?

A. Hop count
B. Bandwidth
C. Delay
D. Cost

Answer: A. Hop count
Explanation:
RIP uses hop count to determine the best path.

188. What does a router do with a packet that has a TTL of 1?

A. Forwards it to the next hop
B. Drops the packet and sends an ICMP Time Exceeded message
C. Sends the packet to the broadcast address
D. Changes the TTL to 255 and forwards

Answer: B. Drops the packet and sends an ICMP Time Exceeded message
Explanation:
TTL prevents infinite looping; when it reaches zero, the packet is discarded.

189. Which command shows the configuration of a specific interface on a Cisco router?

A. show interfaces
B. show running-config interface [interface]
C. show ip interface brief
D. show interfaces status

Answer: B. show running-config interface [interface]
Explanation:
Displays detailed configuration specific to the interface.

190. What is the maximum number of hosts on a /30 subnet?

A. 2
B. 4
C. 6
D. 14

Answer: A. 2
Explanation:
A /30 subnet provides 4 IP addresses, 2 usable (network and broadcast addresses are reserved).

191. What is the purpose of the show version command on a Cisco device?

A. Displays the device’s current configuration
B. Shows the IOS version and device uptime
C. Lists connected devices
D. Shows interface status

Answer: B. Shows the IOS version and device uptime
Explanation:
show version provides important system information including IOS version, uptime, system image, and hardware details.

192. Which of the following protocols is connectionless?

A. TCP
B. UDP
C. FTP
D. SMTP

Answer: B. UDP
Explanation:
UDP is a connectionless protocol that does not guarantee delivery, order, or error checking.

193. What is the default encapsulation type on a Cisco router serial interface?

A. HDLC
B. PPP
C. Frame Relay
D. Ethernet

Answer: A. HDLC
Explanation:
Cisco routers use HDLC as the default Layer 2 encapsulation on serial interfaces unless otherwise configured.

194. What is the function of a VLAN trunk?

A. To increase bandwidth on a switch port
B. To carry traffic for multiple VLANs between switches
C. To assign IP addresses to VLANs
D. To segment collision domains

Answer: B. To carry traffic for multiple VLANs between switches
Explanation:
Trunks carry tagged frames from multiple VLANs over a single physical link.

195. Which protocol is used to synchronize clocks on devices in a network?

A. FTP
B. SNMP
C. NTP
D. DHCP

Answer: C. NTP
Explanation:
Network Time Protocol (NTP) synchronizes clocks of devices on the network.

196. What is the maximum length of a CAT5 Ethernet cable segment?

A. 100 meters
B. 10 meters
C. 1000 meters
D. 500 meters

Answer: A. 100 meters
Explanation:
Standard Ethernet limits cable runs to 100 meters to avoid signal degradation.

197. Which command is used to enable password encryption on Cisco devices?

A. enable secret
B. service password-encryption
C. password encryption aes
D. encrypt passwords

Answer: B. service password-encryption
Explanation:
This command encrypts plaintext passwords in the device configuration.

198. Which of the following is NOT a valid IPv6 address?

A. 2001:0db8::1
B. fe80::1
C. 192.168.1.1
D. ::1

Answer: C. 192.168.1.1
Explanation:
This is an IPv4 address, not IPv6.

199. What is the default administrative distance of static routes?

A. 0
B. 1
C. 90
D. 110

Answer: B. 1
Explanation:
Static routes have an AD of 1 by default, making them more trusted than dynamic routes.

200. What is the role of a Cisco access control list (ACL)?

A. To block unauthorized network access
B. To route packets
C. To assign IP addresses
D. To manage VLANs

Answer: A. To block unauthorized network access
Explanation:
ACLs filter network traffic to control access to network resources.

201. What type of IPv6 address starts with FE80::?

A. Global unicast
B. Link-local
C. Multicast
D. Anycast

Answer: B. Link-local
Explanation:
FE80::/10 addresses are used for local communication within a network segment.

202. What protocol uses port 443 by default?

A. HTTP
B. HTTPS
C. FTP
D. Telnet

Answer: B. HTTPS
Explanation:
HTTPS uses port 443 for secure web traffic.

203. What does the command show ip interface brief display?

A. Detailed interface configurations
B. Summary of interface status and IP addresses
C. Routing table information
D. VLAN assignments

Answer: B. Summary of interface status and IP addresses
Explanation:
This command gives a concise overview of all interfaces, their IPs, and operational status.

204. Which type of routing protocol is BGP?

A. Distance-vector
B. Link-state
C. Path-vector
D. Hybrid

Answer: C. Path-vector
Explanation:
BGP uses path-vector routing, based on AS-path information for inter-AS routing.

205. What is the default VLAN on Cisco switches?

A. VLAN 1
B. VLAN 10
C. VLAN 100
D. VLAN 99

Answer: A. VLAN 1
Explanation:
All switch ports belong to VLAN 1 by default.

206. What is a MAC address?

A. Logical address of a device
B. Physical hardware address of a network interface
C. IP address assigned by DHCP
D. Broadcast address

Answer: B. Physical hardware address of a network interface
Explanation:
MAC addresses uniquely identify network interfaces at Layer 2.

207. What is the purpose of the ping command?

A. To test reachability between hosts
B. To display routing table
C. To display interface configuration
D. To list active connections

Answer: A. To test reachability between hosts
Explanation:
Ping sends ICMP echo requests to check network connectivity.

208. What device operates primarily at the Data Link layer?

A. Router
B. Switch
C. Hub
D. Firewall

Answer: B. Switch
Explanation:
Switches forward frames based on MAC addresses at Layer 2.

209. Which protocol provides remote CLI access using encryption?

A. Telnet
B. SSH
C. FTP
D. HTTP

Answer: B. SSH
Explanation:
SSH encrypts the session, providing secure remote access.

210. What is a collision domain?

A. Network segment where devices share bandwidth and collisions can occur
B. Area of broadcast traffic
C. Group of VLANs
D. Number of hosts per subnet

Answer: A. Network segment where devices share bandwidth and collisions can occur
Explanation:
In shared media, collisions happen when two devices transmit simultaneously.

211. What is the primary benefit of using OSPF over RIP?

A. Simpler configuration
B. Faster convergence and scalability
C. Uses hop count metric only
D. Runs over WAN only

Answer: B. Faster convergence and scalability
Explanation:
OSPF is link-state and converges faster than RIP, which is distance-vector.

212. What does the command enable secret configure?

A. Console password
B. Encrypted privileged EXEC password
C. Password for user login
D. Enable password in plaintext

Answer: B. Encrypted privileged EXEC password
Explanation:
enable secret sets an encrypted password for privileged mode access.

213. What is the maximum cable length for 1000Base-T Ethernet?

A. 10 meters
B. 100 meters
C. 1000 meters
D. 10 kilometers

Answer: B. 100 meters
Explanation:
1000Base-T (Gigabit Ethernet) over copper is limited to 100 meters.

214. What layer is responsible for logical addressing and routing?

A. Physical
B. Data Link
C. Network
D. Transport

Answer: C. Network
Explanation:
The Network layer manages IP addressing and packet forwarding.

215. Which of the following is a characteristic of UDP?

A. Connection-oriented
B. Reliable delivery
C. Low overhead, no connection setup
D. Uses sequence numbers

Answer: C. Low overhead, no connection setup
Explanation:
UDP provides minimal services with no connection establishment.

216. What is a characteristic of a default route (0.0.0.0/0)?

A. Used only in LANs
B. Routes all unknown traffic to a specific next hop
C. Has a metric of 255
D. Used to route multicast traffic

Answer: B. Routes all unknown traffic to a specific next hop
Explanation:
Default routes catch all traffic with no specific route in the table.

217. Which Cisco IOS command can be used to troubleshoot DNS issues?

A. show dns
B. ping with domain names
C. show ip dns
D. traceroute dns

Answer: B. ping with domain names
Explanation:
Pinging domain names tests DNS resolution functionality.

218. What is the use of the show ip protocols command?

A. Displays all IP protocol-related settings and routing protocols in use
B. Shows interface IP addresses
C. Displays VLAN information
D. Shows active sessions

Answer: A. Displays all IP protocol-related settings and routing protocols in use
Explanation:
This command summarizes routing protocols and parameters.

219. What does the acronym ACL stand for?

A. Access Control List
B. Automatic Configuration Link
C. Address Control Layer
D. Access Connection Line

Answer: A. Access Control List
Explanation:
ACLs are used to filter network traffic based on rules.

220. What is the purpose of Spanning Tree Protocol (STP)?

A. To prevent routing loops
B. To prevent Layer 2 switching loops
C. To improve bandwidth
D. To assign IP addresses

Answer: B. To prevent Layer 2 switching loops
Explanation:
STP disables redundant links to avoid broadcast storms and loops in Layer 2.

221. Which of the following IPv4 addresses is a private IP address?

A. 8.8.8.8
B. 192.168.10.5
C. 172.16.0.1
D. Both B and C

Answer: D. Both B and C
Explanation:
Private IPv4 ranges are 10.0.0.0–10.255.255.255, 172.16.0.0–172.31.255.255, and 192.168.0.0–192.168.255.255.

222. What does the show interfaces command display?

A. Routing protocols
B. Interface status, errors, and statistics
C. IP address assignments
D. VLAN information

Answer: B. Interface status, errors, and statistics
Explanation:
This command provides detailed interface-level info including up/down status, bandwidth, errors, and traffic statistics.

223. Which Layer 2 protocol uses a three-way handshake to establish a link?

A. HDLC
B. PPP
C. Ethernet
D. ARP

Answer: B. PPP
Explanation:
PPP uses LCP (Link Control Protocol) to establish, configure, and test the data-link connection.

224. What is the binary equivalent of the subnet mask 255.255.255.240?

A. 11111111.11111111.11111111.11110000
B. 11111111.11111111.11111111.00001111
C. 11111111.11111111.00000000.00000000
D. 11111111.11111111.11111111.11111100

Answer: A. 11111111.11111111.11111111.11110000
Explanation:
255 = 11111111 in binary, so 240 corresponds to 11110000.

225. How many usable hosts are there in a /29 subnet?

A. 6
B. 8
C. 14
D. 30

Answer: A. 6
Explanation:
/29 = 32 – 29 = 3 bits for hosts → 2³ = 8 addresses; subtract 2 for network and broadcast → 6 usable.

226. Which command can you use to configure an interface IP address on a Cisco router?

A. ip address 192.168.1.1 255.255.255.0 under interface configuration mode
B. interface ip address 192.168.1.1 255.255.255.0 in global mode
C. set ip 192.168.1.1 255.255.255.0 under interface mode
D. ip route 192.168.1.1 255.255.255.0

Answer: A. ip address 192.168.1.1 255.255.255.0 under interface configuration mode
Explanation:
Interface IP addresses are assigned in interface configuration mode.

227. What is the role of the Address Resolution Protocol (ARP)?

A. Resolves IP addresses to MAC addresses
B. Resolves MAC addresses to IP addresses
C. Provides IP addressing
D. Routes traffic between VLANs

Answer: A. Resolves IP addresses to MAC addresses
Explanation:
ARP maps Layer 3 IP addresses to Layer 2 MAC addresses on a local network.

228. Which IEEE standard defines Wi-Fi?

A. 802.3
B. 802.11
C. 802.1Q
D. 802.1D

Answer: B. 802.11
Explanation:
802.11 defines wireless LAN (Wi-Fi) standards.

229. What is the purpose of NAT in a network?

A. Translate private IP addresses to public IP addresses
B. Assign IP addresses automatically
C. Secure network traffic
D. Manage VLANs

Answer: A. Translate private IP addresses to public IP addresses
Explanation:
Network Address Translation (NAT) enables multiple devices on a private network to share a public IP address.

230. What is the default metric used by RIP?

A. Bandwidth
B. Hop count
C. Delay
D. Cost

Answer: B. Hop count
Explanation:
RIP uses hop count as its routing metric, limiting routes to a maximum of 15 hops.

231. What command can be used to configure a static route?

A. ip route 192.168.10.0 255.255.255.0 10.0.0.2
B. route add 192.168.10.0 255.255.255.0 10.0.0.2
C. static route 192.168.10.0 255.255.255.0 10.0.0.2
D. ip static-route 192.168.10.0 255.255.255.0 10.0.0.2

Answer: A. ip route 192.168.10.0 255.255.255.0 10.0.0.2
Explanation:
This command configures a static route to the specified network via the next-hop IP.

232. Which VLAN type is used for management purposes on Cisco switches?

A. VLAN 10
B. VLAN 100
C. VLAN 1
D. VLAN 99

Answer: D. VLAN 99 (commonly) or any configured management VLAN
Explanation:
Though VLAN 1 is default, it is recommended to use a separate VLAN (like 99) for management.

233. What does the switchport mode access command do on a Cisco switch?

A. Configures the port as a trunk port
B. Configures the port to only carry traffic for a single VLAN
C. Enables VLAN tagging
D. Disables the port

Answer: B. Configures the port to only carry traffic for a single VLAN
Explanation:
Access mode ports belong to only one VLAN and do not tag frames.

234. What is the command to save the running configuration to the startup configuration?

A. copy running-config startup-config
B. save config
C. write memory
D. Both A and C

Answer: D. Both A and C
Explanation:
copy running-config startup-config and write memory save the current config to persistent memory.

235. What is the use of the show ip route command?

A. Display current routing table entries
B. Show interface status
C. Display VLAN configurations
D. Show ACL rules

Answer: A. Display current routing table entries
Explanation:
It shows routes learned and configured on the router.

236. What is the default administrative distance of OSPF?

A. 90
B. 110
C. 120
D. 1

Answer: B. 110
Explanation:
OSPF has an AD of 110, lower than EIGRP but higher than static routes.

237. Which layer of the OSI model is responsible for end-to-end communication?

A. Data Link
B. Network
C. Transport
D. Session

Answer: C. Transport
Explanation:
The Transport layer ensures reliable end-to-end data delivery (TCP/UDP).

238. What is the maximum number of hosts in a Class C network?

A. 254
B. 256
C. 512
D. 1024

Answer: A. 254
Explanation:
Class C networks have a default mask of 255.255.255.0, providing 256 addresses, minus 2 reserved.

239. Which command enables OSPF routing on a Cisco router?

A. router ospf 1
B. ip ospf enable
C. enable ospf
D. ospf router 1

Answer: A. router ospf 1
Explanation:
This command enters OSPF router configuration mode with process ID 1.

240. What does the acronym DHCP stand for?

A. Dynamic Host Control Protocol
B. Dynamic Host Configuration Protocol
C. Direct Host Control Protocol
D. Distributed Host Configuration Protocol

Answer: B. Dynamic Host Configuration Protocol
Explanation:
DHCP automatically assigns IP addresses to hosts on a network.

241. Which Cisco IOS command disables a switch port?

A. shutdown
B. disable
C. no enable
D. port disable

Answer: A. shutdown
Explanation:
The shutdown command administratively disables an interface.

242. What does the show cdp neighbors command display?

A. Connected devices discovered via Cisco Discovery Protocol
B. Routing table entries
C. VLAN membership
D. IP addresses of remote hosts

Answer: A. Connected devices discovered via Cisco Discovery Protocol
Explanation:
CDP reveals directly connected Cisco devices.

243. What is the purpose of VTP in a Cisco network?

A. To route between VLANs
B. To synchronize VLAN information across switches
C. To encrypt VLAN traffic
D. To assign IP addresses to VLANs

Answer: B. To synchronize VLAN information across switches
Explanation:
VLAN Trunking Protocol helps manage VLAN configuration across multiple switches.

244. Which command can be used to enable SSH on a Cisco router?

A. ip ssh version 2
B. crypto key generate rsa
C. username admin secret password
D. All of the above

Answer: D. All of the above
Explanation:
Generating RSA keys, configuring SSH version, and setting user credentials are all needed for SSH.

245. What is the function of the command no shutdown on an interface?

A. Turns off the interface
B. Enables the interface
C. Resets the interface
D. Displays the interface status

Answer: B. Enables the interface
Explanation:
Interfaces are administratively down by default and must be enabled with no shutdown.

246. Which type of ACL can filter traffic based on source and destination IP address?

A. Standard ACL
B. Extended ACL
C. Named ACL
D. Dynamic ACL

Answer: B. Extended ACL
Explanation:
Extended ACLs filter traffic based on multiple parameters, including source and destination IPs.

247. What device uses ARP to map IP addresses to MAC addresses?

A. Router
B. Switch
C. Host
D. Firewall

Answer: C. Host
Explanation:
Hosts use ARP to resolve MAC addresses for local IP addresses.

248. Which command is used to enter privileged EXEC mode?

A. enable
B. privilege
C. exec
D. configure

Answer: A. enable
Explanation:
enable moves the user from user EXEC to privileged EXEC mode.

249. What is the maximum number of VLANs supported on a Cisco switch?

A. 64
B. 128
C. 255
D. 4096

Answer: D. 4096
Explanation:
VLAN IDs range from 1 to 4094, supporting up to 4096 VLANs.

250. Which routing protocol uses multicast address 224.0.0.5 to communicate between routers?

A. RIP
B. OSPF
C. EIGRP
D. BGP

Answer: B. OSPF
Explanation:
OSPF routers use multicast 224.0.0.5 to send hello packets.

251. Which of the following protocols is used to automatically assign IP addresses to devices on a network?

A) DNS
B) DHCP
C) FTP
D) ICMP

Answer: B) DHCP
Explanation: DHCP (Dynamic Host Configuration Protocol) automatically assigns IP addresses and other network configuration parameters to devices, allowing them to communicate on an IP network without manual configuration.

252. What is the function of the ARP protocol in a network?

A) To resolve IP addresses to MAC addresses
B) To translate domain names to IP addresses
C) To encrypt data packets
D) To establish TCP connections

Answer: A) To resolve IP addresses to MAC addresses
Explanation: ARP (Address Resolution Protocol) maps IP addresses to MAC addresses so devices can communicate on the local Ethernet network.

253. Which Cisco IOS command is used to view the current IP routing table?

A) show ip interface brief
B) show running-config
C) show ip route
D) show interfaces

Answer: C) show ip route
Explanation: The show ip route command displays the current routing table on a Cisco router, listing known networks and the paths to reach them.

254. What is the purpose of VLANs in a switched network?

A) To provide IP addressing to hosts
B) To create separate broadcast domains
C) To enable WAN connections
D) To configure routing between networks

Answer: B) To create separate broadcast domains
Explanation: VLANs (Virtual Local Area Networks) segment a physical LAN into multiple logical broadcast domains, improving security and reducing broadcast traffic.

255. Which routing protocol is a distance-vector protocol that uses hop count as its metric?

A) OSPF
B) EIGRP
C) RIP
D) BGP

Answer: C) RIP
Explanation: RIP (Routing Information Protocol) is a distance-vector routing protocol that uses hop count as its metric, with a maximum of 15 hops allowed.

256. Which of the following is a characteristic of OSPF?

A) It uses distance vector routing
B) It uses the Bellman-Ford algorithm
C) It supports classless routing
D) It only works with IPv4

Answer: C) It supports classless routing
Explanation: OSPF (Open Shortest Path First) is a link-state protocol supporting classless inter-domain routing (CIDR), enabling efficient IP address usage.

257. What does the command switchport mode trunk do on a Cisco switch port?

A) Sets the port to access mode for a single VLAN
B) Allows the port to carry traffic for multiple VLANs
C) Disables the port
D) Enables port security

Answer: B) Allows the port to carry traffic for multiple VLANs
Explanation: Configuring a switch port as a trunk allows it to carry traffic from multiple VLANs across a single physical link using VLAN tagging.

258. Which protocol is responsible for reliable delivery of data in TCP/IP?

A) UDP
B) IP
C) TCP
D) ICMP

Answer: C) TCP
Explanation: TCP (Transmission Control Protocol) provides reliable, connection-oriented communication with error checking and retransmission of lost packets.

259. Which command can be used to secure access to the Cisco device’s console port?

A) line vty 0 4
B) enable secret password
C) line console 0
D) password cisco

Answer: C) line console 0
Explanation: The command line console 0 enters console line configuration mode, where you can configure password and login settings to secure console access.

260. What does NAT stand for, and what is its primary purpose?

A) Network Address Translation; to translate private IP addresses to public IP addresses
B) Network Access Terminal; to provide remote access to networks
C) Network Authentication Tool; to verify user identities
D) Network Allocation Table; to allocate bandwidth

Answer: A) Network Address Translation; to translate private IP addresses to public IP addresses
Explanation: NAT allows multiple devices on a private network to share a single public IP address when accessing the internet.

261. Which layer of the OSI model is responsible for reliable end-to-end communication?

A) Network
B) Data Link
C) Transport
D) Physical

Answer: C) Transport
Explanation: The Transport layer (Layer 4) provides reliable communication through flow control, error detection, and retransmission mechanisms.

262. Which of the following is a valid IPv6 address format?

A) 192.168.1.1
B) FE80::1A2B:3C4D:5E6F:7G8H
C) 2001:0db8:85a3::8a2e:0370:7334
D) 255.255.255.0

Answer: C) 2001:0db8:85a3::8a2e:0370:7334
Explanation: IPv6 addresses use eight groups of four hexadecimal digits separated by colons, with “::” representing a series of zeros.

263. What is the default administrative distance of OSPF?

A) 90
B) 100
C) 110
D) 120

Answer: C) 110
Explanation: OSPF has a default administrative distance of 110, which determines its priority when multiple routing protocols learn about the same route.

264. Which command enables SSH on a Cisco device?

A) ip ssh enable
B) transport input ssh
C) crypto key generate rsa
D) enable ssh

Answer: C) crypto key generate rsa
Explanation: Generating RSA keys with crypto key generate rsa enables SSH on Cisco devices for secure remote management.

265. What is the maximum transmission unit (MTU) size of an Ethernet frame?

A) 1500 bytes
B) 1400 bytes
C) 9000 bytes
D) 512 bytes

Answer: A) 1500 bytes
Explanation: The MTU for standard Ethernet frames is 1500 bytes, which is the largest payload size without fragmentation.

266. Which layer of the OSI model do switches primarily operate on?

A) Layer 1
B) Layer 2
C) Layer 3
D) Layer 4

Answer: B) Layer 2
Explanation: Switches primarily operate at Layer 2 (Data Link Layer) to forward frames based on MAC addresses.

267. What protocol does a router use to dynamically learn routes from other routers?

A) ARP
B) DHCP
C) Routing Protocol
D) ICMP

Answer: C) Routing Protocol
Explanation: Routers use routing protocols like OSPF, EIGRP, or RIP to share routing information and dynamically learn routes.

268. What does the command show interfaces display on a Cisco router?

A) The routing table
B) Configuration of all interfaces
C) Status and statistics for all interfaces
D) Running configuration

Answer: C) Status and statistics for all interfaces
Explanation: The show interfaces command shows interface status, IP addressing, bandwidth, errors, and other statistics.

269. What is the purpose of the Spanning Tree Protocol (STP)?

A) To assign IP addresses
B) To prevent switching loops in a network
C) To encrypt VLAN traffic
D) To provide routing between VLANs

Answer: B) To prevent switching loops in a network
Explanation: STP prevents network loops by blocking redundant paths in a switched LAN topology.

270. Which type of NAT translates multiple private IP addresses to a single public IP address using different ports?

A) Static NAT
B) Dynamic NAT
C) PAT (Port Address Translation)
D) NAT64

Answer: C) PAT (Port Address Translation)
Explanation: PAT, also called NAT overload, allows multiple devices to share a single public IP by differentiating connections using port numbers.

271. In Cisco IOS, which command is used to enter privileged EXEC mode?

A) enable
B) configure terminal
C) exec
D) privileged

Answer: A) enable
Explanation: The enable command switches the user from user EXEC mode to privileged EXEC mode, where advanced commands are available.

272. Which protocol is used to transfer files securely over SSH?

A) FTP
B) TFTP
C) SCP
D) HTTP

Answer: C) SCP
Explanation: SCP (Secure Copy Protocol) transfers files securely over SSH connections.

273. What does the show ip interface brief command provide?

A) Summary of IP interfaces and their statuses
B) Detailed interface statistics
C) Routing table summary
D) VLAN configuration

Answer: A) Summary of IP interfaces and their statuses
Explanation: show ip interface brief provides a quick overview of all interfaces, their IP addresses, and whether they are up or down.

274. Which type of routing protocol is EIGRP classified as?

A) Distance vector
B) Link state
C) Hybrid
D) Path vector

Answer: C) Hybrid
Explanation: EIGRP is considered a hybrid routing protocol because it incorporates features of both distance vector and link-state protocols.

275. What is the function of a default gateway in a network?

A) To provide DNS services
B) To route traffic to other networks
C) To assign IP addresses
D) To manage network security

Answer: B) To route traffic to other networks
Explanation: A default gateway routes traffic from a local network to devices in other networks or the internet.

276. What type of address is FF:FF:FF:FF:FF:FF?

A) Unicast
B) Multicast
C) Broadcast
D) Anycast

Answer: C) Broadcast
Explanation: The MAC address FF:FF:FF:FF:FF:FF is the broadcast address used to send frames to all devices in a LAN.

277. Which wireless standard operates at 5 GHz and supports speeds up to 1.3 Gbps?

A) 802.11b
B) 802.11g
C) 802.11n
D) 802.11ac

Answer: D) 802.11ac
Explanation: 802.11ac operates in the 5 GHz band and supports high data rates up to 1.3 Gbps, ideal for modern Wi-Fi networks.

278. Which Cisco IOS command saves the running configuration to startup configuration?

A) copy startup-config running-config
B) copy running-config startup-config
C) write erase
D) reload

Answer: B) copy running-config startup-config
Explanation: This command saves the current active configuration to NVRAM so that it is used on the next reboot.

279. What does an ACL do in a Cisco router?

A) Manages VLANs
B) Filters traffic based on rules
C) Configures IP addresses
D) Monitors network performance

Answer: B) Filters traffic based on rules
Explanation: An Access Control List (ACL) filters inbound or outbound packets to permit or deny traffic based on IP addresses, ports, or protocols.

280. What type of IPv6 address is FE80::/10?

A) Global Unicast
B) Link-local
C) Multicast
D) Unique Local

Answer: B) Link-local
Explanation: Addresses in the FE80::/10 range are link-local addresses, used for communication within a single network segment.