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
/2211111111111111111111110000000000network bitshost bits

How many usable host addresses H are there in an IPv4 subnet with prefix /22?

/22
H =
2.Easy
/2311111111111111111111111000000000network bitshost bits

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

/23
H =
3.Medium
/20 → /2411111111111111111111111100000000network bitshost bits

The network 10.87.160.0/20 is divided into equal subnets with prefix /24. How many subnets N are there?

10.87.160.0/20/24
N =
4.Medium
/?11111111111111111111100000000000network bitshost bits

A department needs 1091 host addresses in a single subnet. What is the longest prefix length p (smallest subnet) that is big enough?

1091 hosts
p =
5.Hard
third octet 79 … 84012816403201618141211commonvaries

A router has routes to these networks: 10.33.79.0/24, 10.33.80.0/24, 10.33.81.0/24, 10.33.82.0/24, 10.33.83.0/24, 10.33.84.0/24. What is the longest prefix length p of a single summary route that covers all of them?

10.33.79.0/24 … 10.33.84.0/24
p =
6.Hard
last octet = 191112806413211618141211networkhost

A host has the address 10.20.81.191/26. What is the fourth octet x of the last usable host address in its subnet?

10.20.81.191/26
x =

Answer key

  1. 1. H = 1022
  2. 2. H = 510
  3. 3. N = 16
  4. 4. p = 21
  5. 5. p = 19
  6. 6. x = 190

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