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
255.255.255.22411111111111111111111111111100000network bitshost bits

A subnet has the mask 255.255.255.224. What is its prefix length p?

255.255.255.224
p =
2.Easy
/2811111111111111111111111111110000network bitshost bits

How many usable host addresses H are there in an IPv4 subnet with prefix /28?

/28
H =
3.Medium
/?11111111111111111111111110000000network bitshost bits

A department needs 125 host addresses in a single subnet. What is the longest prefix length p (smallest subnet) that is big enough?

125 hosts
p =
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

The network 192.168.131.0/24 is split with VLSM for these LANs: A: 19 hosts, B: 55 hosts, C: 10 hosts, D: 6 hosts, E: 11 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 E?

A: 19B: 55C: 10D: 6E: 11
x =
6.Hard
last octet = 90012816403211618041201networkhost

A host has the address 10.20.27.90/29. What is the last number (fourth octet) x of its subnet's broadcast address?

10.20.27.90/29
x =

Answer key

  1. 1. p = 27
  2. 2. H = 14
  3. 3. p = 25
  4. 4. H = 6
  5. 5. x = 96
  6. 6. x = 95

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