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
/2011111111111111111111000000000000network bitshost bits

How many usable host addresses H are there in an IPv4 subnet with prefix /20?

/20
H =
2.Easy
fourth octet of /30112816413211618140201oneszeros

Write the subnet mask of a /30 network in dotted-decimal notation. What is the value x of its fourth octet?

/30
x =
3.Medium
/24 → /2811111111111111111111111111110000network bitshost bits

The network 192.168.143.0/24 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 network address of subnet 7?

192.168.143.0/24/28subnet 7 (subnet 1 starts at .0)
x =
4.Medium
/20 → /2311111111111111111111111000000000network bitshost bits

The network 10.39.176.0/20 is divided into equal subnets with prefix /23. How many subnets N are there?

10.39.176.0/20/23
N =
5.Hard
third octet 48 … 54012806413211608040201commonvaries

A router has routes to these networks: 10.230.48.0/24, 10.230.49.0/24, 10.230.50.0/24, 10.230.51.0/24, 10.230.52.0/24, 10.230.53.0/24, 10.230.54.0/24. What is the longest prefix length p of a single summary route that covers all of them?

10.230.48.0/24 … 10.230.54.0/24
p =
6.Hard
last octet = 19012806403211608041211networkhost

A host has the address 10.20.176.19/26. What is the last number (fourth octet) x of its subnet's broadcast address?

10.20.176.19/26
x =

Answer key

  1. 1. H = 4094
  2. 2. x = 252
  3. 3. x = 96
  4. 4. N = 8
  5. 5. p = 21
  6. 6. x = 63

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