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
/2111111111111111111111100000000000network bitshost bits

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

/21
H =
2.Easy
/2311111111111111111111111000000000network bitshost bits

How many usable host addresses H are there in an IPv4 subnet with prefix /23?

/23
H =
3.Medium
/24 → /2611111111111111111111111111000000network bitshost bits

The network 192.168.103.0/24 is divided into /26 subnets, numbered 1, 2, 3, … from the lowest address (subnet 1 starts at .0). What is the fourth octet x of the broadcast address of subnet 4?

192.168.103.0/24/26subnet 4 (subnet 1 starts at .0)
x =
4.Medium
/?11111111111111111111111000000000network bitshost bits

A department needs 296 host addresses in a single subnet. What is the longest prefix length p (smallest subnet) that is big enough?

296 hosts
p =
5.Hard
last octet = 32012806413201608040201networkhost

A host has the address 10.20.102.32/30. What is the last number (fourth octet) x of its subnet's broadcast address?

10.20.102.32/30
x =
6.Hard
last octet = 110012816413201618141201networkhost

A host has the address 10.20.18.110/26. What is the fourth octet x of the last usable host address in its subnet?

10.20.18.110/26
x =

Answer key

  1. 1. H = 2046
  2. 2. H = 510
  3. 3. x = 255
  4. 4. p = 23
  5. 5. x = 35
  6. 6. x = 126

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