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
/2511111111111111111111111110000000network bitshost bits

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

/25
H =
3.Medium
/22 → /2911111111111111111111111111111000network bitshost bits

The network 10.138.52.0/22 is divided into equal subnets with prefix /29. How many subnets N are there?

10.138.52.0/22/29
N =
4.Medium
/24 → /2711111111111111111111111111100000network bitshost bits

The network 192.168.151.0/24 is divided into /27 subnets, numbered 1, 2, 3, … from the lowest address (subnet 1 starts at .0). What is the fourth octet x of the network address of subnet 6?

192.168.151.0/24/27subnet 6 (subnet 1 starts at .0)
x =
5.Hard
third octet 19 … 21012806403211608041211commonvaries

A router has routes to these networks: 10.238.19.0/24, 10.238.20.0/24, 10.238.21.0/24. What is the longest prefix length p of a single summary route that covers all of them?

10.238.19.0/24 … 10.238.21.0/24
p =
6.Hard
last octet = 80012816403211608040201networkhost

A host has the address 10.20.231.80/28. What is the fourth octet x of its network address?

10.20.231.80/28
x =

Answer key

  1. 1. H = 510
  2. 2. H = 126
  3. 3. N = 128
  4. 4. x = 160
  5. 5. p = 21
  6. 6. x = 80

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