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
255.255.255.19211111111111111111111111111000000network bitshost bits

A subnet has the mask 255.255.255.192. What is its prefix length p?

255.255.255.192
p =
2.Easy
/2111111111111111111111100000000000network bitshost bits

An access list must match the network 172.16.0.0/21. Access lists use a wildcard mask, the inverse of the subnet mask. What is the third octet x of the wildcard mask?

/21
x =
3.Medium
/24 → /2911111111111111111111111111111000network bitshost bits

The network 192.168.21.0/24 is divided into /29 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 7?

192.168.21.0/24/29subnet 7 (subnet 1 starts at .0)
x =
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 = 94012816403211618141201networkhost

A host has the address 10.20.100.94/29. What is the fourth octet x of its network address?

10.20.100.94/29
x =
6.Hard
last octet = 248112816413211618040201networkhost

A host has the address 10.20.74.248/29. What is the fourth octet x of its network address?

10.20.74.248/29
x =

Answer key

  1. 1. p = 26
  2. 2. x = 7
  3. 3. x = 48
  4. 4. H = 14
  5. 5. x = 88
  6. 6. x = 248

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