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
255.255.255.25211111111111111111111111111111100network bitshost bits

A subnet has the mask 255.255.255.252. What is its prefix length p?

255.255.255.252
p =
2.Easy
/2511111111111111111111111110000000network bitshost bits

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

/25
H =
3.Medium
/16 → /2111111111111111111111100000000000network bitshost bits

The network 172.26.0.0/16 is divided into equal subnets with prefix /21. How many subnets N are there?

172.26.0.0/16/21
N =
4.Medium
/24 → /2911111111111111111111111111111000network bitshost bits

The network 192.168.10.0/24 must be divided into at least 20 equal subnets. If you borrow as few bits as possible, how many usable hosts H does each subnet have?

192.168.10.0/2420 subnets
H =
5.Hard

The network 192.168.255.0/24 is split with VLSM for these LANs: A: 26 hosts, B: 5 hosts, C: 17 hosts, D: 106 hosts. Subnets are allocated from .0 upwards, the LAN with the most hosts first, each with the smallest subnet that fits. What is the fourth octet x of the network address of LAN B?

A: 26B: 5C: 17D: 106
x =
6.Hard
third octet 120 … 124012816413211618040201commonvaries

A router has routes to these networks: 10.63.120.0/24, 10.63.121.0/24, 10.63.122.0/24, 10.63.123.0/24, 10.63.124.0/24. What is the longest prefix length p of a single summary route that covers all of them?

10.63.120.0/24 … 10.63.124.0/24
p =

Answer key

  1. 1. p = 30
  2. 2. H = 126
  3. 3. N = 32
  4. 4. H = 6
  5. 5. x = 192
  6. 6. p = 21

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