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 /21112816413211618040201oneszeros

Write the subnet mask of a /21 network in dotted-decimal notation. What is the value x of its third octet?

/21
x =
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 → /2711111111111111111111111111100000network bitshost bits

The network 10.40.177.0/24 is divided into equal subnets with prefix /27. How many subnets N are there?

10.40.177.0/24/27
N =
4.Medium
255.255.255.25211111111111111111111111111111100network bitshost bits

A subnet uses the mask 255.255.255.252. How many usable host addresses H does it have?

255.255.255.252
H =
5.Hard
last octet = 89012816403211618040211networkhost

A host has the address 10.20.49.89/29. What is the fourth octet x of the last usable host address in its subnet?

10.20.49.89/29
x =
6.Hard
last octet = 36012806413201608140201networkhost

A host has the address 10.20.225.36/29. What is the fourth octet x of the last usable host address in its subnet?

10.20.225.36/29
x =

Answer key

  1. 1. x = 248
  2. 2. H = 254
  3. 3. N = 8
  4. 4. H = 2
  5. 5. x = 94
  6. 6. x = 38

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