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
/2911111111111111111111111111111000network bitshost bits

How many usable host addresses H are there in an IPv4 subnet with prefix /29?

/29
H =
2.Easy
/2011111111111111111111000000000000network bitshost bits

An access list must match the network 172.16.0.0/20. Access lists use a wildcard mask, the inverse of the subnet mask. What is the third octet x of the wildcard mask?

/20
x =
3.Medium
/24 → /2911111111111111111111111111111000network bitshost bits

The network 192.168.10.0/24 must be divided into at least 20 equal subnets. If you borrow as few bits as possible, how many usable hosts H does each subnet have?

192.168.10.0/2420 subnets
H =
4.Medium
/24 → /2911111111111111111111111111111000network bitshost bits

The network 192.168.10.0/24 must be divided into at least 30 equal subnets. If you borrow as few bits as possible, how many usable hosts H does each subnet have?

192.168.10.0/2430 subnets
H =
5.Hard
last octet = 144112806403211608040201networkhost

A host has the address 10.20.120.144/29. What is the fourth octet x of its network address?

10.20.120.144/29
x =
6.Hard

The network 192.168.157.0/24 is split with VLSM for these LANs: A: 5 hosts, B: 18 hosts, C: 7 hosts, D: 17 hosts, E: 56 hosts. Subnets are allocated from .0 upwards, the LAN with the most hosts first, each with the smallest subnet that fits. What is the fourth octet x of the network address of LAN D?

A: 5B: 18C: 7D: 17E: 56
x =

Answer key

  1. 1. H = 6
  2. 2. x = 15
  3. 3. H = 6
  4. 4. H = 6
  5. 5. x = 144
  6. 6. x = 96

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