IPv4 subnetting worksheet with answers

Free printable IPv4 subnetting worksheet: 6 problems from easy to exam level, with an answer key. Print it or save it as a PDF.

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Name: ____________________   Date: ____________

1.Easy
/2311111111111111111111111000000000network bitshost bits

How many usable host addresses H are there in an IPv4 subnet with prefix /23?

/23
H =
2.Easy
/2111111111111111111111100000000000network bitshost bits

How many usable host addresses H are there in an IPv4 subnet with prefix /21?

/21
H =
3.Medium
/?11111111111111111111100000000000network bitshost bits

A department needs 1973 host addresses in a single subnet. What is the longest prefix length p (smallest subnet) that is big enough?

1973 hosts
p =
4.Medium
/22 → /3011111111111111111111111111111100network bitshost bits

The network 10.62.124.0/22 is divided into equal subnets with prefix /30. How many subnets N are there?

10.62.124.0/22/30
N =
5.Hard
third octet 162 … 168112806413201608041201commonvaries

A router has routes to these networks: 10.108.162.0/24, 10.108.163.0/24, 10.108.164.0/24, 10.108.165.0/24, 10.108.166.0/24, 10.108.167.0/24, 10.108.168.0/24. What is the longest prefix length p of a single summary route that covers all of them?

10.108.162.0/24 … 10.108.168.0/24
p =
6.Hard
third octet 155 … 159112806403211618041211commonvaries

A router has routes to these networks: 10.157.155.0/24, 10.157.156.0/24, 10.157.157.0/24, 10.157.158.0/24, 10.157.159.0/24. What is the longest prefix length p of a single summary route that covers all of them?

10.157.155.0/24 … 10.157.159.0/24
p =

Answer key

  1. 1. H = 510
  2. 2. H = 2046
  3. 3. p = 21
  4. 4. N = 256
  5. 5. p = 20
  6. 6. p = 21

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