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

How many usable host addresses H are there in an IPv4 subnet with prefix /20?

/20

H =

2.Easy

An access list must match the network 192.168.1.0/27. Access lists use a wildcard mask, the inverse of the subnet mask. What is the fourth octet x of the wildcard mask?

/27

x =

3.Medium

The network 10.12.48.0/20 is divided into equal subnets with prefix /27. How many subnets N are there?

10.12.48.0/20/27

N =

4.Medium

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

The network 192.168.70.0/24 is split with VLSM for these LANs: A: 9 hosts, B: 6 hosts, C: 36 hosts, D: 16 hosts, E: 10 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: 6C: 36D: 16E: 10

x =

6.Hard

A router has routes to these networks: 10.146.61.0/24, 10.146.62.0/24, 10.146.63.0/24, 10.146.64.0/24, 10.146.65.0/24, 10.146.66.0/24, 10.146.67.0/24, 10.146.68.0/24. What is the longest prefix length p of a single summary route that covers all of them?

10.146.61.0/24 … 10.146.68.0/24

p =

Answer key

1. H = 4094
2. x = 31
3. N = 128
4. H = 6
5. x = 112
6. p = 17

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