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
/2911111111111111111111111111111000network bitshost bits

How many usable host addresses H are there in an IPv4 subnet with prefix /29?

/29
H =
3.Medium
/16 → /1911111111111111111110000000000000network bitshost bits

The network 172.20.0.0/16 is divided into equal subnets with prefix /19. How many subnets N are there?

172.20.0.0/16/19
N =
4.Medium
/?11111111111111111111110000000000network bitshost bits

A department needs 595 host addresses in a single subnet. What is the longest prefix length p (smallest subnet) that is big enough?

595 hosts
p =
5.Hard
last octet = 101012816413201608140211networkhost

A host has the address 10.20.101.101/25. What is the fourth octet x of the last usable host address in its subnet?

10.20.101.101/25
x =
6.Hard
third octet 0 … 1012806403201608040201commonvaries

A router has routes to these networks: 10.26.0.0/24, 10.26.1.0/24. What is the longest prefix length p of a single summary route that covers all of them?

10.26.0.0/24 … 10.26.1.0/24
p =

Answer key

  1. 1. H = 126
  2. 2. H = 6
  3. 3. N = 8
  4. 4. p = 22
  5. 5. x = 126
  6. 6. p = 23

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