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
fourth octet of /29112816413211618040201oneszeros

Write the subnet mask of a /29 network in dotted-decimal notation. What is the value x of its fourth octet?

/29
x =
2.Easy
255.255.252.011111111111111111111110000000000network bitshost bits

A subnet has the mask 255.255.252.0. What is its prefix length p?

255.255.252.0
p =
3.Medium
/24 → /2811111111111111111111111111110000network bitshost bits

The network 192.168.10.0/24 must be divided into at least 10 equal subnets. If you borrow as few bits as possible, how many usable hosts H does each subnet have?

192.168.10.0/2410 subnets
H =
4.Medium
/24 → /2511111111111111111111111110000000network bitshost bits

The network 192.168.133.0/24 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 network address of subnet 2?

192.168.133.0/24/25subnet 2 (subnet 1 starts at .0)
x =
5.Hard
third octet = 223112816403211618141211networkhost

A host has the address 172.20.223.42/22. What is the third octet x of its subnet's broadcast address?

172.20.223.42/22
x =
6.Hard
third octet 49 … 50012806413211608040211commonvaries

A router has routes to these networks: 10.90.49.0/24, 10.90.50.0/24. What is the longest prefix length p of a single summary route that covers all of them?

10.90.49.0/24 … 10.90.50.0/24
p =

Answer key

  1. 1. x = 248
  2. 2. p = 22
  3. 3. H = 14
  4. 4. x = 128
  5. 5. x = 223
  6. 6. p = 22

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