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
/2111111111111111111111100000000000network bitshost bits

How many usable host addresses H are there in an IPv4 subnet with prefix /21?

/21
H =
3.Medium
/?11111111111111111111111000000000network bitshost bits

A department needs 506 host addresses in a single subnet. What is the longest prefix length p (smallest subnet) that is big enough?

506 hosts
p =
4.Medium
/?11111111111111111111111110000000network bitshost bits

A department needs 72 host addresses in a single subnet. What is the longest prefix length p (smallest subnet) that is big enough?

72 hosts
p =
5.Hard
third octet 184 … 189112806413211618040201commonvaries

A router has routes to these networks: 10.246.184.0/24, 10.246.185.0/24, 10.246.186.0/24, 10.246.187.0/24, 10.246.188.0/24, 10.246.189.0/24. What is the longest prefix length p of a single summary route that covers all of them?

10.246.184.0/24 … 10.246.189.0/24
p =
6.Hard
last octet = 110012816413201618141201networkhost

A host has the address 10.20.222.110/27. What is the last number (fourth octet) x of its subnet's broadcast address?

10.20.222.110/27
x =

Answer key

  1. 1. H = 4094
  2. 2. H = 2046
  3. 3. p = 23
  4. 4. p = 25
  5. 5. p = 21
  6. 6. x = 127

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