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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1.Easy
third octet of /18112816403201608040201oneszeros

Write the subnet mask of a /18 network in dotted-decimal notation. What is the value x of its third octet?

/18
x =
2.Easy
third octet of /21112816413211618040201oneszeros

Write the subnet mask of a /21 network in dotted-decimal notation. What is the value x of its third octet?

/21
x =
3.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 =
4.Medium
/24 → /2811111111111111111111111111110000network bitshost bits

The network 192.168.136.0/24 is divided into /28 subnets, numbered 1, 2, 3, … from the lowest address (subnet 1 starts at .0). What is the fourth octet x of the network address of subnet 2?

192.168.136.0/24/28subnet 2 (subnet 1 starts at .0)
x =
5.Hard
last octet = 191112806413211618141211networkhost

A host has the address 10.20.236.191/28. What is the fourth octet x of the last usable host address in its subnet?

10.20.236.191/28
x =
6.Hard
last octet = 116012816413211608140201networkhost

A host has the address 10.20.11.116/29. What is the last number (fourth octet) x of its subnet's broadcast address?

10.20.11.116/29
x =

Answer key

  1. 1. x = 192
  2. 2. x = 248
  3. 3. H = 30
  4. 4. x = 16
  5. 5. x = 190
  6. 6. x = 119

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