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 /26112816403201608040201oneszeros

Write the subnet mask of a /26 network in dotted-decimal notation. What is the value x of its fourth octet?

/26
x =
3.Medium
/?11111111111111111111100000000000network bitshost bits

A department needs 1394 host addresses in a single subnet. What is the longest prefix length p (smallest subnet) that is big enough?

1394 hosts
p =
4.Medium
/?11111111111111111111100000000000network bitshost bits

A department needs 1831 host addresses in a single subnet. What is the longest prefix length p (smallest subnet) that is big enough?

1831 hosts
p =
5.Hard
last octet = 95012816403211618141211networkhost

A host has the address 10.20.213.95/30. What is the fourth octet x of the last usable host address in its subnet?

10.20.213.95/30
x =
6.Hard
third octet 22 … 25012806403211608141201commonvaries

A router has routes to these networks: 10.170.22.0/24, 10.170.23.0/24, 10.170.24.0/24, 10.170.25.0/24. What is the longest prefix length p of a single summary route that covers all of them?

10.170.22.0/24 … 10.170.25.0/24
p =

Answer key

  1. 1. H = 4094
  2. 2. x = 192
  3. 3. p = 21
  4. 4. p = 21
  5. 5. x = 94
  6. 6. p = 20

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