Networking Concepts - Practice MCQs for CCAT

Correct Answer: A - 7

OSI has 7 layers: Physical, Data Link, Network, Transport, Session, Presentation, Application.

Correct Answer: B - Network

Network Layer (Layer 3) handles routing and logical addressing.

Correct Answer: B - Connection-oriented

TCP is connection-oriented and provides reliable data transfer.

Correct Answer: B - Connectionless

UDP is connectionless, faster but unreliable.

Correct Answer: B - Network

IP addresses are Network Layer (Layer 3) addresses.

Correct Answer: A - Data Link

MAC addresses are Data Link Layer (Layer 2) addresses.

Correct Answer: C - TCP

HTTP uses TCP for reliable web page transfer.

Correct Answer: B - 53

DNS uses port 53 for domain name resolution.

Correct Answer: C - Identify network and host portion

Subnet mask separates network and host parts of IP address.

Correct Answer: B - IP to MAC

ARP (Address Resolution Protocol) converts IP address to MAC address.

Correct Answer: C - Transport

Transport layer provides end-to-end reliable data delivery between hosts.

Correct Answer: C - Error reporting and diagnostics

ICMP (Internet Control Message Protocol) is used for error reporting and ping.

Correct Answer: A - Router connecting to other networks

Default gateway is the router that forwards packets to other networks.

Correct Answer: C - Network Address Translation

NAT translates private IP addresses to public IP addresses and vice versa.

Correct Answer: B - Automatic IP address assignment

DHCP (Dynamic Host Configuration Protocol) automatically assigns IP addresses.

Correct Answer: C - 128

IPv6 addresses are 128 bits long, compared to 32 bits for IPv4.

Correct Answer: D - SYN, SYN-ACK, ACK

TCP connection uses SYN, SYN-ACK, ACK for three-way handshake.

Correct Answer: D - HTTPS

HTTPS uses port 443 for secure web communication.

Correct Answer: C - 127.0.0.1

127.0.0.1 is the loopback address used to test network on local machine.

Correct Answer: B - 0.0.0.0 to 127.255.255.255

Class A addresses range from 0.0.0.0 to 127.255.255.255 (first octet 0-127).

Correct Answer: D - 7

The OSI (Open Systems Interconnection) model has 7 layers: Physical, Data Link, Network, Transport, Session, Presentation, and Application.

Correct Answer: B - Network Layer

The Network Layer (Layer 3) handles routing, logical addressing (IP addresses), and path determination. Routers operate at this layer.

Correct Answer: C - TCP is connection-oriented and reliable; UDP is connectionless and unreliable

TCP (Transmission Control Protocol) is connection-oriented, provides reliable delivery with error checking and ordering. UDP (User Datagram Protocol) is connectionless, faster but doesn't guarantee delivery or order.

Correct Answer: D - To translate domain names to IP addresses

DNS (Domain Name System) translates human-readable domain names (like www.example.com) into IP addresses (like 93.184.216.34) that computers use to identify each other on the network.

Correct Answer: D - SMTP

SMTP (Simple Mail Transfer Protocol) is used for sending emails between servers. POP3 and IMAP are used for retrieving emails from a mail server.

Correct Answer: C - To divide an IP address into network and host portions

A subnet mask is used to divide an IP address into network and host portions. It helps routers determine which part of an IP address refers to the network and which part refers to the specific host.

Correct Answer: D - 80

HTTP uses port 80 by default. HTTPS uses port 443, FTP uses port 21, and SMTP uses port 25.

Correct Answer: A - 4

The TCP/IP model has 4 layers: Network Access (Link), Internet, Transport, and Application. It is a simplified version of the OSI model.

Correct Answer: A - Resolving IP addresses to MAC addresses

ARP maps an IP address to a physical (MAC) address on a local network. When a device knows the IP address but needs the MAC address to send a frame, it broadcasts an ARP request.

Correct Answer: B - 254

A /24 subnet has 8 host bits, giving 2⁸ = 256 addresses. Subtracting the network address and broadcast address, the usable host addresses are 256 - 2 = 254.

Correct Answer: D - Switch

A switch operates at the Data Link Layer (Layer 2) and uses MAC addresses to forward frames to the correct port. A router operates at Layer 3, and a hub operates at Layer 1.

Correct Answer: D - To automatically assign IP addresses to devices on a network

DHCP (Dynamic Host Configuration Protocol) automatically assigns IP addresses and other network configuration parameters to devices, eliminating the need for manual IP configuration.

Correct Answer: A - SYN, SYN-ACK, ACK sequence used to establish a connection

TCP uses a three-way handshake to establish a connection: the client sends SYN, the server responds with SYN-ACK, and the client sends ACK. This ensures both sides are ready to communicate.

Correct Answer: D - A hub broadcasts to all ports; a switch forwards to the specific port using MAC addresses

A hub broadcasts incoming data to all ports (Layer 1 device), while a switch learns MAC addresses and forwards data only to the specific port where the destination device is connected (Layer 2 device).

Correct Answer: A - A method of mapping private IP addresses to public IP addresses

NAT translates private IP addresses used within a local network to a public IP address for communication over the internet. It helps conserve the limited number of public IPv4 addresses.

Correct Answer: A - Class C

Class C IP addresses (192.0.0.0 to 223.255.255.255) have a default subnet mask of 255.255.255.0 (/24), allowing for 254 hosts per network.

Correct Answer: D - Sending error messages and operational information about network conditions

ICMP (Internet Control Message Protocol) is used for sending error messages (e.g., destination unreachable) and operational information. The ping and traceroute utilities use ICMP.

Correct Answer: A - End-to-end communication, error recovery, and flow control

The Transport Layer (Layer 4) provides end-to-end communication between hosts, including segmentation, error detection/recovery, flow control, and multiplexing. TCP and UDP operate at this layer.

Correct Answer: D - 4 subnets, 62 hosts each

A /26 subnet uses 2 additional bits for subnetting from a /24 network, giving 2² = 4 subnets. Each subnet has 6 host bits: 2⁶ - 2 = 62 usable hosts per subnet.

Correct Answer: A - A logical grouping of devices on a network regardless of physical location

A VLAN (Virtual Local Area Network) is a logical grouping of devices that can communicate as if they were on the same physical LAN, regardless of their actual physical location. It improves security and reduces broadcast traffic.

Correct Answer: A - POST

The POST method is used to submit data to a server for processing (e.g., form submissions). GET is used to retrieve data, DELETE to remove resources, and HEAD to get headers only.

Correct Answer: C - IPv4 uses 32-bit addresses; IPv6 uses 128-bit addresses

IPv4 uses 32-bit addresses (about 4.3 billion addresses), while IPv6 uses 128-bit addresses (about 3.4×10³⁸ addresses). IPv6 was developed to address the exhaustion of IPv4 addresses.

Correct Answer: C - The maximum number of hops the packet can traverse before being discarded

TTL (Time to Live) specifies the maximum number of router hops a packet can traverse. Each router decrements the TTL by 1. When TTL reaches 0, the packet is discarded, preventing infinite routing loops.

Correct Answer: A - FTP

FTP (File Transfer Protocol) is specifically designed for transferring files between systems over a network. It uses two connections: a control connection (port 21) and a data connection (port 20).

Correct Answer: B - A 48-bit hardware address permanently assigned to a network interface

A MAC (Media Access Control) address is a 48-bit (6-byte) hardware address burned into the network interface card (NIC). It is unique and used for communication within the same local network.

Correct Answer: C - Data translation, encryption, and compression

The Presentation Layer (Layer 6) handles data translation (format conversion), data encryption/decryption, and data compression. It ensures data from the application layer is in a readable format.

Correct Answer: D - A security system that monitors and controls incoming and outgoing network traffic based on rules

A firewall is a network security device or software that monitors and controls incoming and outgoing network traffic based on predetermined security rules, creating a barrier between trusted and untrusted networks.

Correct Answer: A - Flow control and reliable data transfer by allowing multiple frames to be sent before requiring acknowledgment

The sliding window protocol is used for flow control and reliable data transfer. It allows the sender to transmit multiple frames before needing an acknowledgment, improving throughput compared to stop-and-wait.

Correct Answer: B - Transport Layer

The Transport Layer (Layer 4) provides end-to-end error detection and correction. TCP uses checksums, sequence numbers, and acknowledgments to ensure reliable data delivery between endpoints.

Correct Answer: B - HTTP with encryption using SSL/TLS for secure communication

HTTPS (HTTP Secure) is HTTP with encryption using SSL/TLS protocols. It ensures that data transferred between the browser and server is encrypted, preventing eavesdropping and tampering. It uses port 443.