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
/2111111111111111111111100000000000network bitshost bits

How many usable host addresses H are there in an IPv4 subnet with prefix /21?

/21
H =
2.Easy
fourth octet of /30112816413211618140201oneszeros

Write the subnet mask of a /30 network in dotted-decimal notation. What is the value x of its fourth octet?

/30
x =
3.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 =
4.Medium
/24 → /2711111111111111111111111111100000network bitshost bits

The network 192.168.10.0/24 must be divided into at least 8 equal subnets. If you borrow as few bits as possible, how many usable hosts H does each subnet have?

192.168.10.0/248 subnets
H =
5.Hard

The network 192.168.109.0/24 is split with VLSM for these LANs: A: 8 hosts, B: 17 hosts, C: 27 hosts, D: 4 hosts, E: 6 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: 8B: 17C: 27D: 4E: 6
x =
6.Hard
last octet = 193112816403201608040211networkhost

A host has the address 10.20.246.193/28. What is the fourth octet x of the last usable host address in its subnet?

10.20.246.193/28
x =

Answer key

  1. 1. H = 2046
  2. 2. x = 252
  3. 3. N = 4
  4. 4. H = 30
  5. 5. x = 32
  6. 6. x = 206

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