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

An access list must match the network 192.168.1.0/30. Access lists use a wildcard mask, the inverse of the subnet mask. What is the fourth octet x of the wildcard mask?

/30

x =

2.Easy

Write the subnet mask of a /30 network in dotted-decimal notation. What is the value x of its fourth octet?

/30

x =

3.Medium

The network 10.43.224.0/20 is divided into equal subnets with prefix /23. How many subnets N are there?

10.43.224.0/20/23

N =

4.Medium

A department needs 1147 host addresses in a single subnet. What is the longest prefix length p (smallest subnet) that is big enough?

1147 hosts

p =

5.Hard

A router has routes to these networks: 10.245.229.0/24, 10.245.230.0/24, 10.245.231.0/24, 10.245.232.0/24, 10.245.233.0/24, 10.245.234.0/24. What is the longest prefix length p of a single summary route that covers all of them?

10.245.229.0/24 … 10.245.234.0/24

p =

6.Hard

The network 192.168.110.0/24 is split with VLSM for these LANs: A: 9 hosts, B: 55 hosts, C: 20 hosts, D: 104 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 A?

A: 9B: 55C: 20D: 104

x =

Answer key

1. x = 3
2. x = 252
3. N = 8
4. p = 21
5. p = 20
6. x = 224

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