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
/2011111111111111111111000000000000network bitshost bits

An access list must match the network 172.16.0.0/20. Access lists use a wildcard mask, the inverse of the subnet mask. What is the third octet x of the wildcard mask?

/20
x =
2.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 =
3.Medium
/24 → /2511111111111111111111111110000000network bitshost bits

The network 192.168.68.0/24 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?

192.168.68.0/24/25subnet 2 (subnet 1 starts at .0)
x =
4.Medium
/?11111111111111111111100000000000network bitshost bits

A department needs 1745 host addresses in a single subnet. What is the longest prefix length p (smallest subnet) that is big enough?

1745 hosts
p =
5.Hard

The network 192.168.134.0/24 is split with VLSM for these LANs: A: 59 hosts, B: 23 hosts, C: 60 hosts, D: 12 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: 59B: 23C: 60D: 12
x =
6.Hard
last octet = 142112806403201618141201networkhost

A host has the address 10.20.60.142/27. What is the fourth octet x of its network address?

10.20.60.142/27
x =

Answer key

  1. 1. x = 15
  2. 2. p = 27
  3. 3. x = 128
  4. 4. p = 21
  5. 5. x = 128
  6. 6. x = 128

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