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
/2111111111111111111111100000000000network bitshost bits

How many usable host addresses H are there in an IPv4 subnet with prefix /21?

/21
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
/16 → /2011111111111111111111000000000000network bitshost bits

The network 172.25.0.0/16 is divided into equal subnets with prefix /20. How many subnets N are there?

172.25.0.0/16/20
N =
4.Medium
/24 → /2811111111111111111111111111110000network bitshost bits

The network 192.168.166.0/24 is divided into /28 subnets, numbered 1, 2, 3, … from the lowest address (subnet 1 starts at .0). What is the fourth octet x of the broadcast address of subnet 9?

192.168.166.0/24/28subnet 9 (subnet 1 starts at .0)
x =
5.Hard
last octet = 188112806413211618140201networkhost

A host has the address 10.20.16.188/27. What is the last number (fourth octet) x of its subnet's broadcast address?

10.20.16.188/27
x =
6.Hard
last octet = 6012806403201608141201networkhost

A host has the address 10.20.20.6/30. What is the last number (fourth octet) x of its subnet's broadcast address?

10.20.20.6/30
x =

Answer key

  1. 1. H = 2046
  2. 2. H = 126
  3. 3. N = 16
  4. 4. x = 143
  5. 5. x = 191
  6. 6. x = 7

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