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.

New worksheetPractise online with hints

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
/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
255.255.255.12811111111111111111111111110000000network bitshost bits

A subnet uses the mask 255.255.255.128. How many usable host addresses H does it have?

255.255.255.128
H =
4.Medium
/24 → /2911111111111111111111111111111000network bitshost bits

The network 192.168.99.0/24 is divided into /29 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 7?

192.168.99.0/24/29subnet 7 (subnet 1 starts at .0)
x =
5.Hard
third octet 52 … 55012806413211608140201commonvaries

A router has routes to these networks: 10.82.52.0/24, 10.82.53.0/24, 10.82.54.0/24, 10.82.55.0/24. What is the longest prefix length p of a single summary route that covers all of them?

10.82.52.0/24 … 10.82.55.0/24
p =
6.Hard
last octet = 220112816403211618140201networkhost

A host has the address 10.20.46.220/27. What is the last number (fourth octet) x of its subnet's broadcast address?

10.20.46.220/27
x =

Answer key

  1. 1. H = 2046
  2. 2. H = 126
  3. 3. H = 126
  4. 4. x = 48
  5. 5. p = 22
  6. 6. x = 223

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