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
/2511111111111111111111111110000000network bitshost bits

How many usable host addresses H are there in an IPv4 subnet with prefix /25?

/25
H =
2.Easy
/2411111111111111111111111100000000network bitshost bits

How many usable host addresses H are there in an IPv4 subnet with prefix /24?

/24
H =
3.Medium
/24 → /2511111111111111111111111110000000network bitshost bits

The network 192.168.154.0/24 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 broadcast address of subnet 2?

192.168.154.0/24/25subnet 2 (subnet 1 starts at .0)
x =
4.Medium
255.255.255.24011111111111111111111111111110000network bitshost bits

A subnet uses the mask 255.255.255.240. How many usable host addresses H does it have?

255.255.255.240
H =
5.Hard
last octet = 18012806403211608041201networkhost

A host has the address 10.20.224.18/29. What is the fourth octet x of its network address?

10.20.224.18/29
x =
6.Hard
third octet 179 … 181112806413211608041211commonvaries

A router has routes to these networks: 10.115.179.0/24, 10.115.180.0/24, 10.115.181.0/24. What is the longest prefix length p of a single summary route that covers all of them?

10.115.179.0/24 … 10.115.181.0/24
p =

Answer key

  1. 1. H = 126
  2. 2. H = 254
  3. 3. x = 255
  4. 4. H = 14
  5. 5. x = 16
  6. 6. p = 21

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