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
255.255.192.011111111111111111100000000000000network bitshost bits

A subnet has the mask 255.255.192.0. What is its prefix length p?

255.255.192.0
p =
2.Easy
/2111111111111111111111100000000000network bitshost bits

How many usable host addresses H are there in an IPv4 subnet with prefix /21?

/21
H =
3.Medium
/24 → /2811111111111111111111111111110000network bitshost bits

The network 192.168.173.0/24 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 broadcast address of subnet 9?

192.168.173.0/24/28subnet 9 (subnet 1 starts at .0)
x =
4.Medium
/24 → /2911111111111111111111111111111000network bitshost bits

The network 192.168.10.0/24 must be divided into at least 30 equal subnets. If you borrow as few bits as possible, how many usable hosts H does each subnet have?

192.168.10.0/2430 subnets
H =
5.Hard
third octet 160 … 166112806413201608040201commonvaries

A router has routes to these networks: 10.222.160.0/24, 10.222.161.0/24, 10.222.162.0/24, 10.222.163.0/24, 10.222.164.0/24, 10.222.165.0/24, 10.222.166.0/24. What is the longest prefix length p of a single summary route that covers all of them?

10.222.160.0/24 … 10.222.166.0/24
p =
6.Hard
third octet = 132112806403201608140201networkhost

A host has the address 172.20.132.126/18. What is the third octet x of its subnet's broadcast address?

172.20.132.126/18
x =

Answer key

  1. 1. p = 18
  2. 2. H = 2046
  3. 3. x = 143
  4. 4. H = 6
  5. 5. p = 21
  6. 6. x = 191

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