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 /27?

/27

H =

2.Easy

How many usable host addresses H are there in an IPv4 subnet with prefix /26?

/26

H =

3.Medium

The network 192.168.122.0/24 is divided into /26 subnets, numbered 1, 2, 3, … from the lowest address (subnet 1 starts at .0). What is the fourth octet x of the broadcast address of subnet 4?

192.168.122.0/24/26subnet 4 (subnet 1 starts at .0)

x =

4.Medium

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 =

5.Hard

The network 192.168.138.0/24 is split with VLSM for these LANs: A: 3 hosts, B: 29 hosts, C: 99 hosts, D: 18 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: 3B: 29C: 99D: 18

x =

6.Hard

A router has routes to these networks: 10.242.146.0/24, 10.242.147.0/24, 10.242.148.0/24, 10.242.149.0/24. What is the longest prefix length p of a single summary route that covers all of them?

10.242.146.0/24 … 10.242.149.0/24

p =

Answer key

1. H = 30
2. H = 62
3. x = 255
4. H = 30
5. x = 160
6. p = 21

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