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 /17112806403201608040201oneszeros

Write the subnet mask of a /17 network in dotted-decimal notation. What is the value x of its third octet?

/17
x =
2.Easy
255.255.248.011111111111111111111100000000000network bitshost bits

A subnet has the mask 255.255.248.0. What is its prefix length p?

255.255.248.0
p =
3.Medium
/24 → /2611111111111111111111111111000000network bitshost bits

The network 192.168.10.0/24 must be divided into at least 4 equal subnets. If you borrow as few bits as possible, how many usable hosts H does each subnet have?

192.168.10.0/244 subnets
H =
4.Medium
/?11111111111111111111100000000000network bitshost bits

A department needs 1942 host addresses in a single subnet. What is the longest prefix length p (smallest subnet) that is big enough?

1942 hosts
p =
5.Hard
last octet = 125012816413211618140211networkhost

A host has the address 10.20.222.125/30. What is the last number (fourth octet) x of its subnet's broadcast address?

10.20.222.125/30
x =
6.Hard
third octet = 168112806413201618040201networkhost

A host has the address 172.20.168.130/17. What is the third octet x of its subnet's broadcast address?

172.20.168.130/17
x =

Answer key

  1. 1. x = 128
  2. 2. p = 21
  3. 3. H = 62
  4. 4. p = 21
  5. 5. x = 127
  6. 6. x = 255

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