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.

For teachers: free to print, copy and use in class. Every new worksheet has new values and its own answer key. A link to ExamProblems on your course page is appreciated.

Name: ____________________   Date: ____________

1.Easy
255.255.255.24811111111111111111111111111111000network bitshost bits

A subnet has the mask 255.255.255.248. What is its prefix length p?

255.255.255.248
p =
2.Easy
255.255.192.011111111111111111100000000000000network bitshost bits

A subnet has the mask 255.255.192.0. What is its prefix length p?

255.255.192.0
p =
3.Medium
/24 → /2511111111111111111111111110000000network bitshost bits

The network 192.168.173.0/24 is divided into /25 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 2?

192.168.173.0/24/25subnet 2 (subnet 1 starts at .0)
x =
4.Medium
/?11111111111111111111100000000000network bitshost bits

A department needs 1715 host addresses in a single subnet. What is the longest prefix length p (smallest subnet) that is big enough?

1715 hosts
p =
5.Hard
last octet = 132112806403201608140201networkhost

A host has the address 10.20.167.132/26. What is the fourth octet x of the last usable host address in its subnet?

10.20.167.132/26
x =
6.Hard
last octet = 187112806413211618041211networkhost

A host has the address 10.20.193.187/30. What is the last number (fourth octet) x of its subnet's broadcast address?

10.20.193.187/30
x =

Answer key

  1. 1. p = 29
  2. 2. p = 18
  3. 3. x = 255
  4. 4. p = 21
  5. 5. x = 190
  6. 6. x = 187

Full step-by-step solutions: practise this topic on examproblems.com.