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
third octet of /20112816413211608040201oneszeros

Write the subnet mask of a /20 network in dotted-decimal notation. What is the value x of its third octet?

/20
x =
2.Easy
/2211111111111111111111110000000000network bitshost bits

How many usable host addresses H are there in an IPv4 subnet with prefix /22?

/22
H =
3.Medium
/?11111111111111111111110000000000network bitshost bits

A department needs 546 host addresses in a single subnet. What is the longest prefix length p (smallest subnet) that is big enough?

546 hosts
p =
4.Medium
255.255.255.22411111111111111111111111111100000network bitshost bits

A subnet uses the mask 255.255.255.224. How many usable host addresses H does it have?

255.255.255.224
H =
5.Hard
third octet 222 … 226112816403211618141201commonvaries

A router has routes to these networks: 10.125.222.0/24, 10.125.223.0/24, 10.125.224.0/24, 10.125.225.0/24, 10.125.226.0/24. What is the longest prefix length p of a single summary route that covers all of them?

10.125.222.0/24 … 10.125.226.0/24
p =
6.Hard
last octet = 230112816413201608141201networkhost

A host has the address 10.20.24.230/26. What is the last number (fourth octet) x of its subnet's broadcast address?

10.20.24.230/26
x =

Answer key

  1. 1. x = 240
  2. 2. H = 1022
  3. 3. p = 22
  4. 4. H = 30
  5. 5. p = 18
  6. 6. x = 255

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