41. What is the primary role of a firewall in a computer network?
- To assign IP addresses to all connected devices
- To boost the speed of the internet connection
- To monitor and control incoming and outgoing network traffic based on security rules
- To convert domain names into IP addresses
Answer : C Explanation: A firewall acts as a security barrier between a trusted internal network and untrusted external networks like the internet. It inspects traffic and enforces rules that allow or block data packets based on criteria such as IP address, port number, and protocol. Firewalls can be hardware-based, software-based, or both, and are a foundational component of any network security strategy.
42. In which network topology are all devices connected in a circular chain where a failure in one node can affect the entire network?
- Star topology
- Mesh topology
- Bus topology
- Ring topology
Answer : D Explanation: In a ring topology, each device is connected to exactly two neighboring devices, forming a closed circular loop. Data travels in one direction (unidirectional) or both directions (bidirectional, as in dual-ring). The main drawback is that a failure in any single node or cable segment can disrupt communication across the entire network — unless a dual-ring configuration is used for redundancy.
43. What does VPN stand for and what is it used for?
- Virtual Processing Network — used to speed up processors
- Virtual Private Network — creates a secure encrypted connection over a public network
- Verified Protocol Node — verifies network nodes
- Variable Packet Network — varies packet size for efficiency
Answer : B Explanation: A VPN (Virtual Private Network) establishes an encrypted tunnel between a user’s device and a VPN server over a public network like the internet. This protects data from interception and allows remote users to securely access private network resources as if they were physically on that network. VPNs are widely used by businesses for remote work and by individuals for privacy and bypassing geo-restrictions.
44. What is the main purpose of the Spanning Tree Protocol (STP) in a switched network?
- To segment a network into multiple VLANs
- To assign IP addresses to switches
- To prevent switching loops in Layer 2 networks with redundant paths
- To encrypt communication between two switches
Answer : C Explanation: STP (Spanning Tree Protocol) prevents Layer 2 switching loops that occur when multiple redundant paths exist between switches. Without STP, frames could loop endlessly, causing broadcast storms that crash the network. STP works by placing redundant ports in a blocking state so only one active, loop-free path exists between any two devices. RSTP (Rapid STP) is a faster-converging modern version of the protocol.
45. What does “bandwidth” mean in the context of computer networks?
- The physical length of a network cable
- The number of devices connected to a network
- The time delay for a packet to travel from source to destination
- The maximum rate of data transfer across a network connection, measured in bps
Answer : D Explanation: Bandwidth is the maximum capacity of a network connection to transfer data, measured in bits per second (bps), Megabits per second (Mbps), or Gigabits per second (Gbps). It represents how much data can flow through a connection at once — think of it like the width of a pipe. Higher bandwidth means more data can be transmitted simultaneously. Bandwidth is often confused with latency, which measures delay rather than capacity.
46. Which type of cyber attack attempts to make a server or network resource unavailable by overwhelming it with excessive traffic?
- Phishing
- SQL Injection
- Denial of Service (DoS)
- Man-in-the-Middle
Answer : C Explanation: A DoS (Denial of Service) attack floods a target server, service, or network with excessive traffic or requests, exhausting its resources and making it unavailable to legitimate users. When the attack is launched from thousands of compromised machines simultaneously, it is called a DDoS (Distributed Denial of Service) attack, which is far more powerful and harder to stop. These are among the most disruptive threats in modern network security.
47. Which protocol is responsible for sending outgoing emails from a client to a mail server?
- IMAP
- POP3
- HTTP
- SMTP
Answer : D Explanation: SMTP (Simple Mail Transfer Protocol) handles the sending and relaying of outgoing emails between clients and mail servers, and between mail servers themselves. It operates on port 25 (server-to-server) and port 587 (client-to-server submission). For receiving emails, POP3 (port 110) or IMAP (port 143) are used. IMAP is generally preferred over POP3 as it keeps emails on the server and supports multi-device access.
48. What is “latency” in computer networking?
- The maximum speed of a network connection
- The total data capacity of a network
- The time delay for a data packet to travel from its source to its destination
- The number of packets dropped during transmission
Answer : C Explanation: Latency is the time it takes for a data packet to travel from sender to receiver, measured in milliseconds (ms). It is also commonly called “ping.” Low latency is essential for real-time applications such as online gaming, video calls, and financial trading platforms, where even a few milliseconds of delay noticeably impacts performance. Latency is affected by physical distance, network congestion, and the number of hops a packet takes.
49. Which IEEE standard defines the Wi-Fi (Wireless LAN) technology used in most homes and offices today?
- IEEE 802.3
- IEEE 802.11
- IEEE 802.5
- IEEE 802.16
Answer : B Explanation: IEEE 802.11 is the family of standards that defines Wi-Fi (Wireless LAN) communication. It includes multiple versions: 802.11b/g/n (Wi-Fi 4), 802.11ac (Wi-Fi 5), and 802.11ax (Wi-Fi 6), each offering increasing speeds and range. IEEE 802.3 defines wired Ethernet, IEEE 802.5 defines Token Ring, and IEEE 802.16 defines WiMAX. Wi-Fi 6 (802.11ax) is currently the most widely deployed standard in modern devices.
50. What is the difference between HTTP and HTTPS?
- HTTPS is faster than HTTP in all situations
- HTTP uses port 443; HTTPS uses port 80
- HTTPS uses SSL/TLS encryption to protect data in transit; HTTP transmits data in plain text
- HTTP is only used for sending emails; HTTPS is used for file transfers
Answer : C Explanation: HTTPS (HyperText Transfer Protocol Secure) is the encrypted version of HTTP. It uses SSL/TLS (Secure Sockets Layer / Transport Layer Security) to encrypt all data exchanged between a user’s browser and a web server, protecting it from eavesdropping and tampering. HTTP transmits data as plain text, making it vulnerable to interception. HTTPS uses port 443 while HTTP uses port 80. Google also treats HTTPS as a ranking signal, making it important for SEO.
