Cisco CCNA Practice Test — Questions and Answers

Question 1: Which of the following statements concerning TCP and UDP are correct?

TCP is a secure protocol UDP is not secure. (Correct answer)
TCP is slower than UDP. (Correct answer)
UDP has guaranteed transmission
TCP has 8 bits header.
There is no error checking mechanism in UDP (Correct answer)

Correct answer: TCP is a secure protocol UDP is not secure.

Explanation: <br> The main difference between these protocols is that TCP is a connection-oriented protocol, while UDP is a connectionless one. Each of the protocols has its strengths and weaknesses. One is much faster, while the other is safer.

Question 2: Which of the wireless protocols is the most reliable?

WPA3 (Correct answer)
WPA2
WEP
WPA
None of them

Correct answer: WPA3

WPA3 is the latest and most secure wireless security protocol, offering significant improvements over its predecessors like WPA2, WPA, and WEP. It provides enhanced encryption, stronger authentication, and protection against brute-force attacks. These advancements make WPA3 the most reliable choice for securing modern wireless networks.

Question 3: What are the two main types of site-to-site VPNs?

Included Based VPN
Excluded Based VPN
Extranet Based VPN (Correct answer)
Intranet Based VPN (Correct answer)
Internet Based VPN

Correct answer: Extranet Based VPN

Site-to-site VPNs connect entire networks, rather than individual hosts, over a public network. Intranet-based VPNs connect different sites belonging to the *same* organization, allowing secure access to internal resources. Extranet-based VPNs connect different sites of *different* organizations, such as business partners or suppliers, enabling secure collaboration between them.

Question 4: Which of the protocols listed below is a routed protocol?

IP (Correct answer)
STP
OSPF
VTP
RIP

Correct answer: IP

A routed protocol is responsible for carrying user data across an internetwork, providing addressing and encapsulation for data packets. IP (Internet Protocol) is the primary routed protocol, enabling end-to-end communication across diverse networks. Routing protocols like OSPF and RIP, on the other hand, are used by routers to *exchange* routing information about how to reach networks using routed protocols.

Question 5: DSCP bits are____ bits.

3
2
6 (Correct answer)
4
5

Correct answer: 6

DSCP (Differentiated Services Code Point) is a field within the IP header used for Quality of Service (QoS) mechanisms. It consists of 6 bits, which allows for 64 different possible classifications (2^6 = 64) of network traffic. These classifications enable routers to prioritize different types of data, ensuring critical applications receive preferential treatment.

Question 6: What command is used to turn on the Cisco router interface?

no shutdown (Correct answer)
shutdown
run
activate

Correct answer: no shutdown

In Cisco IOS, network interfaces are often administratively shut down by default or can be manually disabled. The `no shutdown` command is used within the interface configuration mode to bring an interface up and enable it to send and receive traffic. This command is essential for activating a router's physical or logical connections.

Question 7: During a Traffic Exceed, QoS.... is the mechanism used. Exceed Traffic is buffered and transmitted again after a brief delay.

Traffic Shaping (Correct answer)
Traffic Determining
Traffic Monitoring
Traffic Selecting

Correct answer: Traffic Shaping

Traffic shaping is a Quality of Service (QoS) mechanism designed to manage and smooth out network traffic flow. When traffic exceeds a configured rate, traffic shaping buffers the excess packets and then transmits them at a regulated, consistent pace. This prevents bursts of data from overwhelming the network, reducing congestion and packet loss for critical applications.

Question 8: True/False: On Ethernet technology, CSMA/CD mechanisms prevent transmission at the same time.

A) False
B) True (Correct answer)

Correct answer: B) True

CSMA/CD (Carrier Sense Multiple Access with Collision Detection) is a media access control method used in half-duplex Ethernet networks. It ensures that devices listen for ongoing transmissions before sending data and detect collisions if they occur. Upon detecting a collision, devices stop transmitting, wait a random period, and then retransmit, effectively preventing simultaneous transmissions and managing shared media access.

Question 9: What are the REST's primary characteristics?

Lightweight
Flexible
Platform-agnostic
Scalable
All of them (Correct answer)

Correct answer: All of them

REST (Representational State Transfer) is an architectural style for designing networked applications, particularly web services. Its primary characteristics include being lightweight due to its use of standard HTTP methods, flexible in handling various data formats, platform-agnostic as it can be implemented across different technologies, and scalable because of its stateless nature. These attributes make REST a popular choice for modern API design.

Question 10: Instead of SNMP, SDN uses ____ as a network configuration management protocol.

Rest
Open Flow
SMTP
Netconf (Correct answer)

Correct answer: Netconf

SDN (Software-Defined Networking) centralizes network control and management, requiring programmatic configuration capabilities. While SNMP is primarily for monitoring, NETCONF (Network Configuration Protocol) is an XML-based protocol specifically designed for configuring network devices. It offers robust, programmatic configuration management, making it a suitable protocol for the automated and centralized control plane of SDN architectures.

Question 11: To learn an unknown MAC address, what does a PC broadcast?

ARP Reply
ARP Request (Correct answer)
ICMP Request
None of the above

Correct answer: ARP Request

When a PC needs to communicate with another device on the same local network but does not know its MAC address, it uses ARP (Address Resolution Protocol). The PC broadcasts an ARP Request packet containing the target device's IP address. The device with that specific IP address then responds with an ARP Reply, providing its MAC address to the requesting PC.

Question 12: The ____ protocol is used to manage network devices.

SNMP (Correct answer)
SMTP
RSTP
OSPF

Correct answer: SNMP

SNMP (Simple Network Management Protocol) is a widely used application-layer protocol for managing and monitoring network devices. It allows network administrators to collect information, modify configurations, and receive alerts about the status of routers, switches, servers, and other network equipment. SNMP is crucial for network operations, performance monitoring, and troubleshooting.

Question 13: Which of the following protocols is a Distance Vector Protocol?

BGP
RIP (Correct answer)
EIGRP
OSPF

Correct answer: RIP

Distance Vector routing protocols determine the best path to a destination based on the 'distance' (e.g., hop count) and the 'direction' (vector) to reach it, typically relying on information from directly connected neighbors. RIP (Routing Information Protocol) is a classic example of a distance vector protocol, using hop count as its primary metric and periodically exchanging full routing tables with its neighbors.

Question 14: To identify traffic bottlenecks between two sites, which router command is used?

SSH
Telnet
Ping
Trace (Correct answer)

Correct answer: Trace

The `traceroute` (or `trace` on Cisco devices, `tracert` on Windows) command is used to display the path and measure transit delays of packets across an IP network. By showing each router (hop) a packet traverses and the round-trip time to each hop, it helps identify where delays or bottlenecks might be occurring between two sites. This makes it ideal for diagnosing connectivity and performance issues.

Question 15: What are some examples of Denial of Service Attacks? (Choose three)

Smurfing (Correct answer)
TCP SYN Flood Attack (Correct answer)
Ping of Death (Correct answer)
ARP Spoofing
DNS Spoofing

Correct answer: Smurfing

Denial of Service (DoS) attacks aim to make a network service unavailable to legitimate users. A TCP SYN Flood overwhelms a server by sending numerous SYN requests without completing the three-way handshake. A Ping of Death involves sending oversized or malformed ICMP packets that can crash older systems. Smurfing is a distributed DoS attack that uses ICMP echo requests directed at an IP broadcast address to amplify traffic to a victim.

Question 16: If Dynamic ARP Inspection (DAI) is enabled,.... is checked, and this ARP packet is permitted if the incoming MAC address is in this table.

IP-MAC Binding Table (Correct answer)
MAC Table
RIB Table
None of the above

Correct answer: IP-MAC Binding Table

Dynamic ARP Inspection (DAI) is a security feature that prevents ARP spoofing and poisoning attacks by validating ARP packets. When DAI is enabled, it checks incoming ARP packets against the IP-MAC binding table, which is often populated by DHCP snooping. If an ARP packet's source IP-MAC address pair does not match an entry in this trusted table, the packet is dropped, preventing unauthorized ARP traffic.

Question 17: If each site has a centralized WLAN Controller and Access Points attached to it, this is...

Flexconnect Wireless Network Design
Classic Wireless Network Design
Centralized Wireless Network Design (Correct answer)
None of the above

Correct answer: Centralized Wireless Network Design

In a centralized wireless network design, a single or cluster of WLAN controllers manages all access points (APs) across different sites. The APs act as 'thin' clients, forwarding all wireless traffic to the central controller for processing, security, and management. This architecture simplifies management, provides consistent policy enforcement, and centralizes control over the entire wireless infrastructure.

Question 18: True/False: The Internet Protocol (IP) is a connectionless protocol.

A) False
B) True (Correct answer)

Correct answer: B) True

The Internet Protocol (IP) is a connectionless protocol, meaning that each packet is treated independently without any prior connection establishment or guarantee of delivery. IP focuses on efficient, best-effort delivery of individual datagrams across networks. Reliability, ordering, and error checking are handled by higher-layer protocols like TCP.

Question 19: What is the broadcast address for a 192.168.145.0 Class C address with the default Subnet Mask?

192.168.145.0
192.168.145.1
192.168.0.0
192.168.145.255 (Correct answer)

Correct answer: 192.168.145.255

For a Class C address like 192.168.145.0 with the default subnet mask (255.255.255.0 or /24), the first three octets identify the network (192.168.145). The last octet is reserved for host addresses. The broadcast address is obtained by setting all host bits to 1, which for the last octet means 255. Therefore, the broadcast address is 192.168.145.255.

Question 20: What protocols are Link State Routing?

EIGRP
OSPF (Correct answer)
IS-IS (Correct answer)
RIP

Correct answer: OSPF

Link-state routing protocols build a complete topological map of the network. Each router exchanges Link State Advertisements (LSAs) with all other routers in its area, describing its directly connected links and their states. OSPF (Open Shortest Path First) and IS-IS (Intermediate System to Intermediate System) are the two most prominent examples of link-state routing protocols, known for their fast convergence and efficient routing.

Question 21: Which of the following technologies is Fast Ethernet?

100BASE-TX (Correct answer)
1000BASE-F
100BASE-5
100BASE2
100BASE-FX (Correct answer)

Correct answer: 100BASE-TX

Fast Ethernet refers to Ethernet standards that support a data rate of 100 Mbps. 100BASE-TX uses two pairs of unshielded twisted-pair (UTP) cable, while 100BASE-FX uses fiber optic cable. Both are common implementations of Fast Ethernet, providing a significant speed upgrade from the original 10 Mbps Ethernet standards.

Question 22: What are the RPVST+ states?

Forwarding
Learning
Blocking
Disabled
All of the above (Correct answer)

Correct answer: All of the above

RPVST+ (Rapid Per-VLAN Spanning Tree Plus) is a Cisco proprietary enhancement of RSTP, designed to prevent loops in switched networks. It utilizes several port states to achieve this: Blocking (prevents forwarding), Learning (learns MAC addresses but doesn't forward), Forwarding (forwards traffic), and Disabled (administratively shut down). These states ensure a loop-free topology while allowing for rapid convergence.

Question 23: What are the ones that are used with NAT?

Inside local
Outside global
Outside local
Inside global
All of the above (Correct answer)

Correct answer: All of the above

NAT (Network Address Translation) uses several terms to describe IP addresses from different perspectives during translation. 'Inside local' is the private IP address of a host on the internal network. 'Inside global' is the public IP address used to represent the inside local address to the outside world. 'Outside local' is the private IP address of an outside host as seen by the inside network, and 'Outside global' is the public IP address of an outside host.

Question 24: Which of these is the Cisco-developed Neighbour Discovery Protocol?

CDP (Correct answer)
ICMP
IGMP
CGMP

Correct answer: CDP

CDP (Cisco Discovery Protocol) is a Cisco proprietary Layer 2 protocol used to discover information about directly connected Cisco devices. It allows devices to share details such as device type, IOS version, capabilities, and connected interface. This protocol is invaluable for network documentation, troubleshooting, and managing Cisco-centric network environments.

Question 25: For a boot system, the router looks to....

Flash
RAM
NVRAM (Correct answer)
CPU

Correct answer: NVRAM

For a boot system, a Cisco router typically looks to NVRAM (Non-Volatile RAM) to find the startup configuration file. This file contains the saved configuration commands that the router loads and executes upon startup, including interface settings, routing protocols, and other operational parameters. While the IOS image might be in Flash, the configuration itself resides in NVRAM.

Cisco CCNA Practice Test

Which of the following statements concerning TCP and UDP are correct?