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
fourth octet of /28112816413211608040201oneszeros

Write the subnet mask of a /28 network in dotted-decimal notation. What is the value x of its fourth octet?

/28
x =
2.Easy
/2911111111111111111111111111111000network bitshost bits

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

/29
H =
3.Medium
/?11111111111111111111111000000000network bitshost bits

A department needs 299 host addresses in a single subnet. What is the longest prefix length p (smallest subnet) that is big enough?

299 hosts
p =
4.Medium
/20 → /2811111111111111111111111111110000network bitshost bits

The network 10.143.48.0/20 is divided into equal subnets with prefix /28. How many subnets N are there?

10.143.48.0/20/28
N =
5.Hard
third octet = 134112806403201608141201networkhost

A host has the address 172.20.134.42/19. What is the third octet x of its network address?

172.20.134.42/19
x =
6.Hard
last octet = 50012806413211608041201networkhost

A host has the address 10.20.98.50/27. What is the fourth octet x of the last usable host address in its subnet?

10.20.98.50/27
x =

Answer key

  1. 1. x = 240
  2. 2. H = 6
  3. 3. p = 23
  4. 4. N = 256
  5. 5. x = 128
  6. 6. x = 62

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