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
/2411111111111111111111111100000000network bitshost bits

How many usable host addresses H are there in an IPv4 subnet with prefix /24?

/24
H =
2.Easy
/1711111111111111111000000000000000network bitshost bits

An access list must match the network 172.16.0.0/17. Access lists use a wildcard mask, the inverse of the subnet mask. What is the third octet x of the wildcard mask?

/17
x =
3.Medium
/?11111111111111111111111000000000network bitshost bits

A department needs 316 host addresses in a single subnet. What is the longest prefix length p (smallest subnet) that is big enough?

316 hosts
p =
4.Medium
/24 → /2811111111111111111111111111110000network bitshost bits

The network 192.168.10.0/24 must be divided into at least 16 equal subnets. If you borrow as few bits as possible, how many usable hosts H does each subnet have?

192.168.10.0/2416 subnets
H =
5.Hard
last octet = 254112816413211618141201networkhost

A host has the address 10.20.7.254/25. What is the last number (fourth octet) x of its subnet's broadcast address?

10.20.7.254/25
x =
6.Hard
last octet = 62012806413211618141201networkhost

A host has the address 10.20.106.62/25. What is the fourth octet x of the last usable host address in its subnet?

10.20.106.62/25
x =

Answer key

  1. 1. H = 254
  2. 2. x = 127
  3. 3. p = 23
  4. 4. H = 14
  5. 5. x = 255
  6. 6. x = 126

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