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
/1811111111111111111100000000000000network bitshost bits

An access list must match the network 172.16.0.0/18. Access lists use a wildcard mask, the inverse of the subnet mask. What is the third octet x of the wildcard mask?

/18
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
/20 → /2811111111111111111111111111110000network bitshost bits

The network 10.68.208.0/20 is divided into equal subnets with prefix /28. How many subnets N are there?

10.68.208.0/20/28
N =
4.Medium
/?11111111111111111111111111100000network bitshost bits

A department needs 18 host addresses in a single subnet. What is the longest prefix length p (smallest subnet) that is big enough?

18 hosts
p =
5.Hard
last octet = 37012806413201608140211networkhost

A host has the address 10.20.38.37/29. What is the fourth octet x of the last usable host address in its subnet?

10.20.38.37/29
x =
6.Hard
last octet = 205112816403201618140211networkhost

A host has the address 10.20.53.205/28. What is the last number (fourth octet) x of its subnet's broadcast address?

10.20.53.205/28
x =

Answer key

  1. 1. x = 63
  2. 2. H = 254
  3. 3. N = 256
  4. 4. p = 27
  5. 5. x = 38
  6. 6. x = 207

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