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
255.255.255.19211111111111111111111111111000000network bitshost bits

A subnet has the mask 255.255.255.192. What is its prefix length p?

255.255.255.192
p =
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 → /2311111111111111111111111000000000network bitshost bits

The network 10.52.16.0/20 is divided into equal subnets with prefix /23. How many subnets N are there?

10.52.16.0/20/23
N =
4.Medium
/24 → /2711111111111111111111111111100000network bitshost bits

The network 192.168.197.0/24 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 3?

192.168.197.0/24/27subnet 3 (subnet 1 starts at .0)
x =
5.Hard
third octet 136 … 141112806403201618040201commonvaries

A router has routes to these networks: 10.74.136.0/24, 10.74.137.0/24, 10.74.138.0/24, 10.74.139.0/24, 10.74.140.0/24, 10.74.141.0/24. What is the longest prefix length p of a single summary route that covers all of them?

10.74.136.0/24 … 10.74.141.0/24
p =
6.Hard
last octet = 218112816403211618041201networkhost

A host has the address 10.20.127.218/30. What is the fourth octet x of the last usable host address in its subnet?

10.20.127.218/30
x =

Answer key

  1. 1. p = 26
  2. 2. H = 510
  3. 3. N = 8
  4. 4. x = 64
  5. 5. p = 21
  6. 6. x = 218

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