Computer Networks MCQs with Solutions to Practice Networking

Answer: b) A group of connected computers and devices that share resources and communicate   

Explanation: A computer network consists of multiple interconnected devices, such as computers, servers, and peripherals, which communicate and share resources like files, printers, or internet connections. This allows users to share data, collaborate, and access common resources more efficiently. 

Answer: b) Switch   

Explanation: Switches work at the Data Link layer (Layer 2), forwarding frames based on MAC addresses, improving efficiency compared to hubs. 

Answer: d) A personal area network (PAN)   

Explanation: Bluetooth is a wireless technology standard designed for exchanging data over short distances, typically between personal devices like smartphones, headphones, and computers. This forms a Personal Area Network (PAN), which has a limited range (usually within 10 meters) and is used for short-range communication. 

Answer: a) Overlay network   

Explanation: An overlay network is built on top of another network. It uses the infrastructure of an existing network (like the internet) to establish a virtual network that can provide additional features such as increased scalability, routing efficiency, or new forms of communication like peer-to-peer (P2P) networks or virtual private networks (VPNs). 

Answer: c) Open System Interconnection   

Explanation: The OSI model (Open Systems Interconnection) is a conceptual framework used to understand and implement standardized communication between computer systems. It divides the process of network communication into seven distinct layers, each with specific functions, ranging from physical hardware to software applications. 

Answer: d) Distributed system   

Explanation: A distributed system is a collection of independent computers that work together as a single system for users. This system allows multiple machines to cooperate and share resources, providing better performance, fault tolerance, and scalability, making it appear as a single coherent system to clients. 

Answer: b) Divide the IP address into network and host portions   

Explanation: Subnet masks separate the network and host parts of an IP address, enabling subnetting and efficient IP allocation. 

Answer: d) All of the above   

Explanation: A node refers to any device connected to a computer network, which can originate, route, or terminate data communication. Nodes include devices such as computers, routers, switches, servers, or any machine capable of receiving or transmitting data. 

Answer: b) Error control   

Explanation: The network layer is responsible for routing, forwarding, and inter-networking, which involves moving data across multiple networks. Error control is generally handled at the Data Link and Transport layers, where mechanisms like checksums and acknowledgments ensure data is transferred correctly. 

Answer: a) Multiplexing   

Explanation: Multiplexing is a method used in communication networks to combine multiple signals for transmission over a single communication channel or medium. This process maximizes the efficiency of data transmission, allowing multiple streams to coexist and reducing the need for additional channels. 

Answer: d) Router   

Explanation: A router is a network device responsible for forwarding data packets between different networks. It uses the destination IP address within the packet to determine the best path for forwarding the data across interconnected networks. 

Answer: c) Socket   

Explanation: A socket is an endpoint in a networked communication flow between two machines or processes. It is associated with a particular IP address and port number, allowing network applications to establish and maintain connections for data exchange. 

Answer: b) The Standby router assumes the Virtual IP and MAC address   

Explanation: HSRP provides high availability by allowing a Standby router to monitor the Active router. If the Active fails, the Standby takes over the virtual gateway IP almost instantaneously, ensuring no loss of connectivity for end-users.

Answer: c) Network layer   

Explanation: The data link layer is responsible for encapsulating packets from the network layer into frames for transmission across the physical medium. It ensures error detection and manages access to the shared communication medium, preparing the data for transmission. 

Answer: a) Switch   

Explanation: A switch is a network device used to connect multiple devices within a LAN, facilitating communication between them. PCs, smartphones, and servers are examples of edge devices, which connect to the network and directly interact with the end-users. 

Answer: b) SFTP   

Explanation: SFTP (Secure File Transfer Protocol) encrypts data during transfer, ensuring confidentiality and integrity compared to FTP. 

Answer: c) VTP (VLAN Trunking Protocol) 

Explanation: VTP allows a network manager to create or delete a VLAN on a "Server" switch and have that change propagate to all other "Client" switches in the same VTP domain. 

Answer: c) A distributed database system   

Explanation: The Domain Name System (DNS) is a distributed database system that translates domain names (e.g., www.example.com) into IP addresses. DNS servers are spread globally and work together to provide name resolution services, ensuring that users can access websites by entering domain names instead of numerical IP addresses. 

Answer: b) A file used to define and identify network attacks   

Explanation: In Intrusion Detection Systems (IDS) and Intrusion Prevention Systems (IPS), a signature is a set of rules or patterns that help identify known malicious activities or attacks on a network. The system compares network traffic with predefined signatures to detect potential threats. 

Answer: c) To reduce the number of OSPF adjacencies and LSA traffic.   

Explanation: In a broadcast network, the DR serves as the central point for routing information exchange. This prevents every router from forming a "full mesh" of adjacencies, significantly lowering network overhead. 

Answer: a) Flow control   

Explanation: Flow control is a technique used to manage the rate of data transmission between sender and receiver, preventing congestion. It ensures that a sender does not overwhelm a network or a receiver with too much data at once, allowing the network to operate smoothly without packet loss or delays. 

Answer: d) Pulse-code modulation   

Explanation: Optical fiber communication primarily uses pulse-code modulation (PCM), which is a method used to digitally represent analog signals. It converts analog signals into a digital bitstream for transmission, offering high-quality signal transmission with low error rates in fiber optic networks. 

Answer: b) To forward data to all connected devices   

Explanation: A network hub is a basic networking device that broadcasts incoming data to all devices connected to it. Unlike a switch or router, a hub does not filter or manage data traffic. It simply forwards incoming packets to all devices, regardless of their destination, which can lead to network inefficiency and congestion. 

Answer: c) Star topology   

Explanation: In a star topology, all devices (or nodes) are connected to a single central hub or switch. The hub acts as the central point of communication, directing data between devices. This topology is commonly used in local area networks (LANs) and offers easy troubleshooting since each device has a direct connection to the hub. 

Answer: a) To protect the network from unauthorized access   

Explanation: A firewall is a security device that monitors and controls incoming and outgoing network traffic based on predetermined security rules. It serves as a barrier between an internal network and external networks (such as the internet), preventing unauthorized access and protecting against various cyber threats. 

Answer: c) Ring topology   

Explanation: In a ring topology, devices are connected in a circular loop, where each device has exactly two neighbors. Data travels in one or both directions around the ring until it reaches its intended destination. This topology can offer efficient communication but may suffer from a single point of failure if any device or connection fails. 

Answer: a) Virtual Private Network   

Explanation: A Virtual Private Network (VPN) creates a secure, encrypted connection over a public network, such as the Internet, allowing users to access a private network remotely. It ensures privacy and security by encrypting data transmitted between the user's device and the VPN server, preventing eavesdropping and unauthorized access. 

Answer: c) Establishing, maintaining, and terminating connections   

Explanation: The transport layer (Layer 4 of the OSI model) is responsible for ensuring reliable communication between two devices over a network. It manages connections, flow control, and error recovery. Protocols such as TCP and UDP operate at this layer, providing mechanisms for reliable data transfer. 

Answer: c) SMTP   

Explanation: The Simple Mail Transfer Protocol (SMTP) is used for sending emails from a client to a server or between servers. It handles the process of relaying, sending, and receiving email messages across the Internet. 

Answer: b) To convert domain names into IP addresses   

Explanation: A DNS server resolves human-readable domain names (such as www.example.com) into machine-readable IP addresses. This enables users to access websites using easy-to-remember domain names instead of numerical IP addresses.