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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1.Easy
/1711111111111111111000000000000000network bitshost bits

An access list must match the network 172.16.0.0/17. Access lists use a wildcard mask, the inverse of the subnet mask. What is the third octet x of the wildcard mask?

/17
x =
2.Easy
/2211111111111111111111110000000000network bitshost bits

How many usable host addresses H are there in an IPv4 subnet with prefix /22?

/22
H =
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 1584 host addresses in a single subnet. What is the longest prefix length p (smallest subnet) that is big enough?

1584 hosts
p =
5.Hard
last octet = 115012816413211608041211networkhost

A host has the address 10.20.154.115/29. What is the fourth octet x of the last usable host address in its subnet?

10.20.154.115/29
x =
6.Hard
last octet = 39012806413201608141211networkhost

A host has the address 10.20.192.39/26. What is the last number (fourth octet) x of its subnet's broadcast address?

10.20.192.39/26
x =

Answer key

  1. 1. x = 127
  2. 2. H = 1022
  3. 3. H = 62
  4. 4. p = 21
  5. 5. x = 118
  6. 6. x = 63

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