ACP Networking Fundamentals 2 — Questions and Answers
Question 1: Which protocol operates at Layer 3 of the OSI model and is responsible for logical addressing and routing?
- TCP
- IP (Correct answer)
- Ethernet
- ARP
Correct answer: IP
IP (Internet Protocol) operates at OSI Layer 3 and handles logical addressing and packet routing between networks.
Question 2: What is the default subnet mask for a Class B IPv4 address?
- 255.0.0.0
- 255.255.0.0 (Correct answer)
- 255.255.255.0
- 255.255.255.128
Correct answer: 255.255.0.0
Class B addresses (128.0.0.0–191.255.255.255) use a default subnet mask of 255.255.255.0, providing 16 network bits.
Question 3: Which switching method begins forwarding a frame as soon as the destination MAC address is read, before the full frame is received?
- Store-and-forward
- Cut-through (Correct answer)
- Fragment-free
- Adaptive switching
Correct answer: Cut-through
Cut-through switching forwards frames immediately after reading the destination MAC address, minimizing latency.
Question 4: What does the TTL field in an IP packet header primarily prevent?
- Packet fragmentation
- Routing loops causing infinite circulation (Correct answer)
- Duplicate packet delivery
- Out-of-order packet arrival
Correct answer: Routing loops causing infinite circulation
TTL (Time to Live) prevents packets from circulating indefinitely by decrementing at each hop and discarding the packet when TTL reaches zero.
Question 5: In a full-duplex Ethernet connection, what is eliminated compared to half-duplex?
- Broadcasts
- CSMA/CD collisions (Correct answer)
- Unicast traffic
- MAC address learning
Correct answer: CSMA/CD collisions
Full-duplex Ethernet eliminates CSMA/CD collisions by allowing simultaneous send and receive on separate wire pairs.
Question 6: Which address type is used to send a packet to all devices within a specific multicast group?
- Broadcast address
- Anycast address
- Multicast address (Correct answer)
- Unicast address
Correct answer: Multicast address
Multicast addresses (224.0.0.0–239.255.255.255) deliver packets to all members of a subscribed multicast group.
Question 7: What is the primary function of the Spanning Tree Protocol (STP) in a switched network?
- Assign IP addresses dynamically
- Prevent Layer 2 broadcast storms by eliminating loops (Correct answer)
- Encrypt traffic between switches
- Balance load across multiple uplinks
Correct answer: Prevent Layer 2 broadcast storms by eliminating loops
STP prevents Layer 2 loops and broadcast storms by blocking redundant paths while keeping them available for failover.
ACP Networking Fundamentals 2
Which protocol operates at Layer 3 of the OSI model and is responsible for logical addressing and routing?