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
/2511111111111111111111111110000000network bitshost bits

How many usable host addresses H are there in an IPv4 subnet with prefix /25?

/25
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
/24 → /2811111111111111111111111111110000network bitshost bits

The network 10.201.225.0/24 is divided into equal subnets with prefix /28. How many subnets N are there?

10.201.225.0/24/28
N =
4.Medium
/?11111111111111111111100000000000network bitshost bits

A department needs 1877 host addresses in a single subnet. What is the longest prefix length p (smallest subnet) that is big enough?

1877 hosts
p =
5.Hard
third octet 225 … 226112816413201608040211commonvaries

A router has routes to these networks: 10.44.225.0/24, 10.44.226.0/24. What is the longest prefix length p of a single summary route that covers all of them?

10.44.225.0/24 … 10.44.226.0/24
p =
6.Hard
last octet = 4012806403201608140201networkhost

A host has the address 10.20.87.4/27. What is the fourth octet x of the last usable host address in its subnet?

10.20.87.4/27
x =

Answer key

  1. 1. H = 126
  2. 2. H = 2046
  3. 3. N = 16
  4. 4. p = 21
  5. 5. p = 22
  6. 6. x = 30

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