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
/2311111111111111111111111000000000network bitshost bits

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

/23
H =
2.Easy
255.255.224.011111111111111111110000000000000network bitshost bits

A subnet has the mask 255.255.224.0. What is its prefix length p?

255.255.224.0
p =
3.Medium
/24 → /2511111111111111111111111110000000network bitshost bits

The network 192.168.41.0/24 is divided into /25 subnets, numbered 1, 2, 3, … from the lowest address (subnet 1 starts at .0). What is the fourth octet x of the network address of subnet 2?

192.168.41.0/24/25subnet 2 (subnet 1 starts at .0)
x =
4.Medium
255.255.240.011111111111111111111000000000000network bitshost bits

A subnet uses the mask 255.255.240.0. How many usable host addresses H does it have?

255.255.240.0
H =
5.Hard
third octet 168 … 174112806413201618040201commonvaries

A router has routes to these networks: 10.158.168.0/24, 10.158.169.0/24, 10.158.170.0/24, 10.158.171.0/24, 10.158.172.0/24, 10.158.173.0/24, 10.158.174.0/24. What is the longest prefix length p of a single summary route that covers all of them?

10.158.168.0/24 … 10.158.174.0/24
p =
6.Hard
third octet = 87012816403211608141211networkhost

A host has the address 172.20.87.226/19. What is the third octet x of its subnet's broadcast address?

172.20.87.226/19
x =

Answer key

  1. 1. H = 510
  2. 2. p = 19
  3. 3. x = 128
  4. 4. H = 4094
  5. 5. p = 21
  6. 6. x = 95

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