CompTIA Network+ Network+ Networking Fundamentals 2 — Questions and Answers
Question 1: Which layer of the OSI model is responsible for logical addressing and routing packets between networks?
- Data Link
- Transport
- Network (Correct answer)
- Session
Correct answer: Network
The Network layer (Layer 3) handles logical addressing (IP) and routing packets across different networks.
Question 2: A device receives a frame but the destination MAC address does not match its own and it is not a broadcast. What does a switch do with this frame?
- Drops the frame immediately
- Forwards it out the correct port based on its MAC table (Correct answer)
- Sends it to the default gateway
- Broadcasts it to all ports
Correct answer: Forwards it out the correct port based on its MAC table
A switch uses its MAC address table to forward unicast frames out the specific port associated with the destination MAC.
Question 3: Which protocol operates at Layer 4 and provides connection-oriented, reliable data delivery?
- UDP
- ICMP
- TCP (Correct answer)
- ARP
Correct answer: TCP
TCP (Transmission Control Protocol) establishes a connection via a three-way handshake and guarantees reliable, ordered delivery.
Question 4: What is the purpose of a default gateway on a host?
- Resolve hostnames to IP addresses
- Assign IP addresses dynamically
- Forward traffic destined for remote networks (Correct answer)
- Filter incoming packets by port number
Correct answer: Forward traffic destined for remote networks
The default gateway is the router interface a host uses to send packets to destinations outside its local subnet.
Question 5: Which networking device operates at Layer 2 and uses MAC addresses to forward frames only to the appropriate port?
- Router
- Hub
- Switch (Correct answer)
- Repeater
Correct answer: Switch
A switch operates at the Data Link layer and makes forwarding decisions based on destination MAC addresses.
Question 6: What does the acronym CSMA/CD stand for and which network type uses it?
- Carrier Sense Multiple Access/Collision Detection — used in traditional wired Ethernet (Correct answer)
- Channel Switching Multiple Access/Collision Detection — used in Wi-Fi
- Carrier Sense Media Access/Circuit Detection — used in fiber optics
- Circuit Switched Multiple Access/Collision Delay — used in token ring
Correct answer: Carrier Sense Multiple Access/Collision Detection — used in traditional wired Ethernet
CSMA/CD (Carrier Sense Multiple Access/Collision Detection) is the access method used by traditional half-duplex Ethernet to detect and handle collisions.
Question 7: Which class of IPv4 address uses a default subnet mask of 255.255.0.0?
- Class A
- Class B (Correct answer)
- Class C
- Class D
Correct answer: Class B
Class B addresses (128.0.0.0–191.255.255.255) have a default subnet mask of 255.255.0.0 (/16).
CompTIA Network+ Network+ Networking Fundamentals 2
Which layer of the OSI model is responsible for logical addressing and routing packets between networks?