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 172.16.0.0/17. Access lists use a wildcard mask, the inverse of the subnet mask. What is the third octet x of the wildcard mask?

/17

x =

2.Easy

How many usable host addresses H are there in an IPv4 subnet with prefix /23?

/23

H =

3.Medium

The network 192.168.32.0/24 is divided into /28 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 8?

192.168.32.0/24/28subnet 8 (subnet 1 starts at .0)

x =

4.Medium

The network 192.168.10.0/24 must be divided into at least 6 equal subnets. If you borrow as few bits as possible, how many usable hosts H does each subnet have?

192.168.10.0/246 subnets

H =

5.Hard

A router has routes to these networks: 10.189.194.0/24, 10.189.195.0/24, 10.189.196.0/24, 10.189.197.0/24, 10.189.198.0/24, 10.189.199.0/24. What is the longest prefix length p of a single summary route that covers all of them?

10.189.194.0/24 … 10.189.199.0/24

p =

6.Hard

A host has the address 10.20.31.136/29. What is the fourth octet x of its network address?

10.20.31.136/29

x =

Answer key

1. x = 127
2. H = 510
3. x = 112
4. H = 30
5. p = 21
6. x = 136

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