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
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 =
2.Easy
/2611111111111111111111111111000000network bitshost bits

How many usable host addresses H are there in an IPv4 subnet with prefix /26?

/26
H =
3.Medium
/24 → /2811111111111111111111111111110000network bitshost bits

The network 192.168.28.0/24 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 broadcast address of subnet 9?

192.168.28.0/24/28subnet 9 (subnet 1 starts at .0)
x =
4.Medium
/?11111111111111111111100000000000network bitshost bits

A department needs 1262 host addresses in a single subnet. What is the longest prefix length p (smallest subnet) that is big enough?

1262 hosts
p =
5.Hard
last octet = 47012806413201618141211networkhost

A host has the address 10.20.158.47/29. What is the fourth octet x of the last usable host address in its subnet?

10.20.158.47/29
x =
6.Hard
third octet = 151112806403211608141211networkhost

A host has the address 172.20.151.196/19. What is the third octet x of its subnet's broadcast address?

172.20.151.196/19
x =

Answer key

  1. 1. x = 192
  2. 2. H = 62
  3. 3. x = 143
  4. 4. p = 21
  5. 5. x = 46
  6. 6. x = 159

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