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
255.255.255.24011111111111111111111111111110000network bitshost bits

A subnet has the mask 255.255.255.240. What is its prefix length p?

255.255.255.240
p =
3.Medium
/?11111111111111111111100000000000network bitshost bits

A department needs 1203 host addresses in a single subnet. What is the longest prefix length p (smallest subnet) that is big enough?

1203 hosts
p =
4.Medium
/24 → /2811111111111111111111111111110000network bitshost bits

The network 192.168.92.0/24 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 network address of subnet 10?

192.168.92.0/24/28subnet 10 (subnet 1 starts at .0)
x =
5.Hard
third octet = 168112806413201618040201networkhost

A host has the address 172.20.168.26/19. What is the third octet x of its subnet's broadcast address?

172.20.168.26/19
x =
6.Hard
last octet = 123012816413211618041211networkhost

A host has the address 10.20.87.123/28. What is the fourth octet x of the last usable host address in its subnet?

10.20.87.123/28
x =

Answer key

  1. 1. H = 510
  2. 2. p = 28
  3. 3. p = 21
  4. 4. x = 144
  5. 5. x = 191
  6. 6. x = 126

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