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
255.255.255.24811111111111111111111111111111000network bitshost bits

A subnet has the mask 255.255.255.248. What is its prefix length p?

255.255.255.248
p =
2.Easy
/2011111111111111111111000000000000network bitshost bits

How many usable host addresses H are there in an IPv4 subnet with prefix /20?

/20
H =
3.Medium
/24 → /2611111111111111111111111111000000network bitshost bits

The network 192.168.10.0/24 must be divided into at least 4 equal subnets. If you borrow as few bits as possible, how many usable hosts H does each subnet have?

192.168.10.0/244 subnets
H =
4.Medium
/24 → /2811111111111111111111111111110000network bitshost bits

The network 192.168.10.0/24 must be divided into at least 10 equal subnets. If you borrow as few bits as possible, how many usable hosts H does each subnet have?

192.168.10.0/2410 subnets
H =
5.Hard
third octet = 47012806413201618141211networkhost

A host has the address 172.20.47.16/23. What is the third octet x of its network address?

172.20.47.16/23
x =
6.Hard
last octet = 129112806403201608040211networkhost

A host has the address 10.20.158.129/25. What is the fourth octet x of the last usable host address in its subnet?

10.20.158.129/25
x =

Answer key

  1. 1. p = 29
  2. 2. H = 4094
  3. 3. H = 62
  4. 4. H = 14
  5. 5. x = 46
  6. 6. x = 254

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