Computer Knowledge

Computer Networks

2,461 Questions

Computer networks involve the architecture, protocols, and security measures used for digital communication. This collection covers OSI model layers, IP addressing, data transmission, and cryptographic standards. These concepts are vital for the computer knowledge sections of banking and government exams.

OSI model layersNetwork protocolsIP subnet maskingData encryption standardsServer configurationsNetwork commands

Computer Networks Questions

Multiple choice

Which are the sub-layers of the Data Link Layer?

  1. MAC and ODP

  2. LLC and PPP

  3. LDP and MAC

  4. LLC and MAC
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The Data Link Layer (Layer 2 of the OSI model) is divided into two sub-layers: the Logical Link Control (LLC) sub-layer and the Media Access Control (MAC) sub-layer.

Multiple choice

Which encryption protocol provides network layer confidentiality?

  1. IPsec protocol suite

  2. Secure Sockets Layer

  3. Message Digest 5

  4. Secure Hash Algorithm 1
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

IPsec is a suite of protocols designed to provide security at the network layer, including confidentiality through encryption. SSL/TLS operates at the transport/application layer, while MD5 and SHA-1 are hashing algorithms, not encryption protocols.

Multiple choice

Wireshark is a ____________ tool.

  1. network protocol analysis

  2. network connection security

  3. connection analysis

  4. defending malicious packet-filtering
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Wireshark is a widely used network protocol analyzer. It allows users to capture and interactively browse the traffic running on a computer network.

Multiple choice

Which Nmap scan is does not completely open a TCP connection?

  1. SYN stealth scan

  2. TCP connect

  3. XMAS tree scan

  4. ACK scan
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A SYN stealth scan (half-open scan) sends a SYN packet to the target. If a SYN/ACK is received, the port is open, but the scanner sends an RST packet instead of completing the handshake, thus avoiding a full connection.

Multiple choice

What is fullform of NMAP?

  1. Network Mapping

  2. Network Management

  3. Network Mapper

  4. Network Monitoring
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Nmap stands for Network Mapper. It is a free and open-source utility for network discovery and security auditing.

Multiple choice

DDoS stands for _________________

  1. Direct Distribution of Server

  2. Distributed Denial of Service

  3. Direct Distribution of Service

  4. Distributed Denial of Server
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

DDoS is an acronym for Distributed Denial of Service. It involves multiple compromised systems flooding a target with traffic to make it unavailable.

Multiple choice

A packet with all flags set is which type of scan?

  1. Full Open

  2. Syn scan

  3. XMAS

  4. TCP connect
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

An XMAS scan sets the FIN, URG, and PUSH flags in a TCP packet. It is called an XMAS scan because the flags are 'lit up' like a Christmas tree.

Multiple choice

What are the three types of scanning?

  1. Port, network, and vulnerability

  2. Port, network, and services

  3. Grey, black, and white hat

  4. Server, client, and network
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Scanning in cybersecurity typically refers to port scanning, network scanning, and vulnerability scanning. These processes help identify open ports, active hosts, and security weaknesses.

Multiple choice

What port number does FTP use?

  1. 21

  2. 25

  3. 23

  4. 80
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

File Transfer Protocol (FTP) uses port 21 for the control connection. Port 20 is typically used for the data connection.

Multiple choice

What is the first step in establishing an IPsec VPN?

  1. detection of interesting traffic

  2. negotiation of ISAKMP policies

  3. creation of a tunnel to negotiate a security associat-policy

  4. creation of an IPsec tunnel between two IPsec peers
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Before any tunnel can be established, the gateway must identify traffic that is designated to be protected by the IPsec tunnel, which is known as interesting traffic.