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
third octet of /18112816403201608040201oneszeros

Write the subnet mask of a /18 network in dotted-decimal notation. What is the value x of its third octet?

/18
x =
2.Easy
/2711111111111111111111111111100000network bitshost bits

How many usable host addresses H are there in an IPv4 subnet with prefix /27?

/27
H =
3.Medium
/24 → /2711111111111111111111111111100000network bitshost bits

The network 192.168.10.0/24 must be divided into at least 6 equal subnets. If you borrow as few bits as possible, how many usable hosts H does each subnet have?

192.168.10.0/246 subnets
H =
4.Medium
/16 → /1911111111111111111110000000000000network bitshost bits

The network 172.26.0.0/16 is divided into equal subnets with prefix /19. How many subnets N are there?

172.26.0.0/16/19
N =
5.Hard
third octet 230 … 232112816413201608141201commonvaries

A router has routes to these networks: 10.28.230.0/24, 10.28.231.0/24, 10.28.232.0/24. What is the longest prefix length p of a single summary route that covers all of them?

10.28.230.0/24 … 10.28.232.0/24
p =
6.Hard

The network 192.168.225.0/24 is split with VLSM for these LANs: A: 5 hosts, B: 17 hosts, C: 11 hosts, D: 18 hosts, E: 4 hosts. Subnets are allocated from .0 upwards, the LAN with the most hosts first, each with the smallest subnet that fits. What is the fourth octet x of the network address of LAN C?

A: 5B: 17C: 11D: 18E: 4
x =

Answer key

  1. 1. x = 192
  2. 2. H = 30
  3. 3. H = 30
  4. 4. N = 8
  5. 5. p = 20
  6. 6. x = 64

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