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
/2911111111111111111111111111111000network bitshost bits

How many usable host addresses H are there in an IPv4 subnet with prefix /29?

/29
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
/16 → /1811111111111111111100000000000000network bitshost bits

The network 172.27.0.0/16 is divided into equal subnets with prefix /18. How many subnets N are there?

172.27.0.0/16/18
N =
5.Hard
third octet = 148112806403211608140201networkhost

A host has the address 172.20.148.243/23. What is the third octet x of its network address?

172.20.148.243/23
x =
6.Hard

The network 192.168.226.0/24 is split with VLSM for these LANs: A: 52 hosts, B: 20 hosts, C: 3 hosts, D: 9 hosts, E: 13 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: 52B: 20C: 3D: 9E: 13
x =

Answer key

  1. 1. x = 15
  2. 2. H = 6
  3. 3. N = 32
  4. 4. N = 4
  5. 5. x = 148
  6. 6. x = 64

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