Describe an IPv4 Network Address and Subnet

Question 1

How many bits are in an IPv4 address?

Answer 1

32 bits

Question 2

What are the two main parts of an IPv4 address?

Answer 2

The network portion, and the host portion.

Question 3

What is the purpose of a subnet mask?

Answer 3

To divide the IP address into two portions - the network portion, and the host portion.

Question 4

How does a subnet mask determine the network and host portions of an IP address?

Answer 4

It uses binary ones (1s) to represent the network portion, and binary zeros (0s) to represent the host portion.

Question 5

What is the default subnet mask for a Class A IP address?

Answer 5

255.0.0.0

Question 6

What is the default subnet mask for a Class B IP address?

Answer 6

255.255.0.0

Question 7

What is the default subnet mask for a Class C IP address?

Answer 7

255.255.255.0

Question 8

What does CIDR stand for and how does it relate to subnetting?

Answer 8

CIDR stands for Classless Inter-Domain Routing. It allows for more flexible subnetting by using a suffix to indicate the number of bits used for the network portion, such as /24.

Question 9

How many usable hosts, and what is the subnet mask, for a /25 subnet?

Answer 9

126 hosts
255.255.255.128

Question 10

How many usable hosts, and what is the subnet mask, for a /26 subnet?

Answer 10

62 hosts
255.255.255.192

Question 11

How many usable hosts, and what is the subnet mask, for a /27 subnet?

Answer 11

30 hosts
255.255.255.224

Question 12

How many usable hosts, and what is the subnet mask, for a /28 subnet?

Answer 12

14 hosts
255.255.255.240

Question 13

How many usable hosts, and what is the subnet mask, for a /29 subnet?

Answer 13

6 hosts
255.255.255.248

Question 14

How many usable hosts, and what is the subnet mask, for a /30 subnet?

Answer 14

2 hosts
255.255.255.252

Question 15

What are the RFC1918 address ranges?

Answer 15

10.0.0.0/8

172.16.0.0/12

192.168.0.0/16