BSCS : Network Fundamentals 2 — Questions and Answers
Question 1: Which layer of the OSI model is responsible for logical addressing and routing packets across networks?
- Data Link Layer
- Transport Layer
- Network Layer (Correct answer)
- Session Layer
Correct answer: Network Layer
The Network Layer (Layer 3) handles logical addressing (IP addresses) and determines the best path for routing packets between networks.
Question 2: What is the subnet mask for a /26 CIDR block?
- 255.255.255.192 (Correct answer)
- 255.255.255.128
- 255.255.255.224
- 255.255.255.240
Correct answer: 255.255.255.192
A /26 prefix means 26 bits are used for the network portion, leaving 6 bits for hosts, giving a subnet mask of 255.255.255.192.
Question 3: Which protocol uses a three-way handshake to establish a connection before data transfer?
- UDP
- ICMP
- TCP (Correct answer)
- ARP
Correct answer: TCP
TCP uses a SYN, SYN-ACK, ACK three-way handshake to establish a reliable connection before transmitting data.
Question 4: In classful IPv4 addressing, which range of first-octet values identifies a Class B network?
- 1–126
- 128–191 (Correct answer)
- 192–223
- 224–239
Correct answer: 128–191
Class B networks have first-octet values from 128 to 191 and use a default /16 subnet mask.
Question 5: What does ARP (Address Resolution Protocol) map?
- Domain names to IP addresses
- IP addresses to MAC addresses (Correct answer)
- Port numbers to services
- MAC addresses to VLAN IDs
Correct answer: IP addresses to MAC addresses
ARP resolves a known IP address to the corresponding MAC (physical) address on a local network segment.
Question 6: Which device operates at Layer 2 of the OSI model and forwards frames based on MAC address tables?
- Router
- Hub
- Switch (Correct answer)
- Repeater
Correct answer: Switch
A switch maintains a MAC address table and forwards Ethernet frames only to the port associated with the destination MAC address.
Question 7: What is the primary purpose of DHCP in a network?
- Translate domain names to IP addresses
- Automatically assign IP configuration to hosts (Correct answer)
- Encrypt network traffic
- Route packets between subnets
Correct answer: Automatically assign IP configuration to hosts
DHCP dynamically assigns IP addresses, subnet masks, default gateways, and DNS server addresses to client devices.
BSCS : Network Fundamentals 2
Which layer of the OSI model is responsible for logical addressing and routing packets across networks?