CCST Subnetting and CIDR Notation 1 — Questions and Answers
Question 1: What does CIDR stand for in networking?
- Classless Inter-Domain Routing (Correct answer)
- Classful Internet Domain Routing
- Common Internet Data Routing
- Cisco Inter-Domain Routing
Correct answer: Classless Inter-Domain Routing
CIDR stands for Classless Inter-Domain Routing, a method for allocating IP addresses and routing that replaced the older classful network system.
Question 2: Which subnet mask corresponds to the /24 prefix length in CIDR notation?
- 255.255.0.0
- 255.255.255.0 (Correct answer)
- 255.0.0.0
- 255.255.255.128
Correct answer: 255.255.255.0
A /24 prefix means 24 bits are set to 1 in the subnet mask, which equals 255.255.255.0 in dotted-decimal notation.
Question 3: How many usable host addresses are available in a /27 subnet?
- 32
- 30 (Correct answer)
- 28
- 16
Correct answer: 30
A /27 subnet has 5 host bits (32-27=5), giving 2^5=32 total addresses minus 2 (network and broadcast) = 30 usable hosts.
Question 4: What is the network address for the host 192.168.10.35/28?
- 192.168.10.32 (Correct answer)
- 192.168.10.16
- 192.168.10.48
- 192.168.10.0
Correct answer: 192.168.10.32
A /28 mask (255.255.255.240) has a block size of 16; the subnets are .0, .16, .32, .48 — host .35 falls in the .32 subnet.
Question 5: Which class of IPv4 addresses uses the 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) use a default subnet mask of 255.255.0.0, providing a /16 prefix.
Question 6: How many bits are in the host portion of a /26 subnet?
- 8
- 4
- 6 (Correct answer)
- 2
Correct answer: 6
IPv4 addresses have 32 bits total; subtracting the /26 prefix leaves 32-26=6 bits for the host portion.
Question 7: What is the broadcast address for the network 10.0.0.0/8?
- 10.255.255.254
- 10.0.0.255
- 10.255.255.255 (Correct answer)
- 10.0.255.255
Correct answer: 10.255.255.255
The broadcast address is the last address in the subnet; for 10.0.0.0/8, all host bits are set to 1, giving 10.255.255.255.
CCST Subnetting and CIDR Notation 1
What does CIDR stand for in networking?