ICND1 Network Fundamentals & IP Addressing 3 — Questions and Answers
Question 1: How many subnets are created when you borrow 3 bits from the host portion of a Class C address?
- 6
- 8 (Correct answer)
- 14
- 16
Correct answer: 8
Borrowing 3 bits yields 2^3 = 8 subnets (using the all-zeroes and all-ones subnets per modern practice).
Question 2: What type of IPv4 address is 169.254.10.5?
- Private
- Loopback
- APIPA / link-local (Correct answer)
- Multicast
Correct answer: APIPA / link-local
The 169.254.0.0/16 range is APIPA (Automatic Private IP Addressing), assigned when DHCP is unavailable.
Question 3: Which device operates at Layer 1 and simply regenerates the electrical signal?
- Bridge
- Hub (Correct answer)
- Switch
- Router
Correct answer: Hub
A hub is a Layer 1 device that repeats electrical signals out all ports without any intelligence.
Question 4: What is the decimal value of the binary number 11001010?
- 194
- 202 (Correct answer)
- 198
- 206
Correct answer: 202
128+64+8+2 = 202 (bits 7,6,3,1 are set).
Question 5: Which class of IP address uses the default subnet mask 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 mask of 255.255.0.0 (/16).
Question 6: A packet destined for 192.168.1.255 on a /24 network is sent as what type of transmission?
- Unicast
- Multicast
- Directed broadcast (Correct answer)
- Limited broadcast
Correct answer: Directed broadcast
192.168.1.255 is the directed (subnet) broadcast for 192.168.1.0/24, sent to all hosts on that subnet.
Question 7: Which layer of the TCP/IP model corresponds to OSI Layers 5, 6, and 7 combined?
- Transport
- Internet
- Network Access
- Application (Correct answer)
Correct answer: Application
The TCP/IP Application layer combines OSI Session (5), Presentation (6), and Application (7) layers.
ICND1 Network Fundamentals & IP Addressing 3
How many subnets are created when you borrow 3 bits from the host portion of a Class C address?