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
/2311111111111111111111111000000000network bitshost bits

How many usable host addresses H are there in an IPv4 subnet with prefix /23?

/23
H =
2.Easy
fourth octet of /26112816403201608040201oneszeros

Write the subnet mask of a /26 network in dotted-decimal notation. What is the value x of its fourth octet?

/26
x =
3.Medium
/24 → /2611111111111111111111111111000000network bitshost bits

The network 192.168.10.0/24 must be divided into at least 3 equal subnets. If you borrow as few bits as possible, how many usable hosts H does each subnet have?

192.168.10.0/243 subnets
H =
4.Medium
255.255.255.19211111111111111111111111111000000network bitshost bits

A subnet uses the mask 255.255.255.192. How many usable host addresses H does it have?

255.255.255.192
H =
5.Hard
third octet 141 … 148112806403201618140211commonvaries

A router has routes to these networks: 10.209.141.0/24, 10.209.142.0/24, 10.209.143.0/24, 10.209.144.0/24, 10.209.145.0/24, 10.209.146.0/24, 10.209.147.0/24, 10.209.148.0/24. What is the longest prefix length p of a single summary route that covers all of them?

10.209.141.0/24 … 10.209.148.0/24
p =
6.Hard
third octet 234 … 241112816413201618041201commonvaries

A router has routes to these networks: 10.136.234.0/24, 10.136.235.0/24, 10.136.236.0/24, 10.136.237.0/24, 10.136.238.0/24, 10.136.239.0/24, 10.136.240.0/24, 10.136.241.0/24. What is the longest prefix length p of a single summary route that covers all of them?

10.136.234.0/24 … 10.136.241.0/24
p =

Answer key

  1. 1. H = 510
  2. 2. x = 192
  3. 3. H = 62
  4. 4. H = 62
  5. 5. p = 19
  6. 6. p = 19

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