7.1.4.9 Lab – Identifying IPv4 Addresses Answers
Lab– Identifying IPv4 Addresses (Answers Version – Optional Lab)
Answers Note: Red font color or gray highlights indicate text that appears in the instructor copy only. Optional activities are designed to enhance understanding and/or to provide additional practice.
Objectives
Part 1: Identify IPv4 Addresses
Part 2: Classify IPv4 Addresses
Background / Scenario
In this lab, you will examine the structure of Internet Protocol version 4 (IPv4) addresses. You will identify the various types of IPv4 addresses and the components that help comprise the address, such as network portion, host portion, and subnet mask. Types of addresses covered include public, private, unicast, and multicast.
Answers Note: This optional activity can be done individually in class or assigned as homework. The lab can also be done in class with students working in pairs. If the lab is done in class, it should be followed up by discussion with correct answers. All public IP addresses used in this lab are owned by Cisco.
Required Resources
- Device with Internet access
- Optional: IPv4 address calculator
Part 1: Identify IPv4 Addresses
Step 1: In Part 1, you will be given several examples of IPv4 addresses and will complete tables with appropriate information.
Step 1: Analyze the table shown below and identify the network portion and host portion of the given IPv4 addresses.
The first two rows show examples of how the table should be completed.
Key for table:
N = all 8 bits for an octet are in the network portion of the address
n = a bit in the network portion of the address
H = all 8 bits for an octet are in the host portion of the address
h = a bit in the host portion of the address
| IP Address/Prefix | Network/Host
N,n = Network, H,h = Host |
Subnet Mask | Network Address |
| 192.168.10.10/24 | N.N.N.H | 255.255.255.0 | 192.168.10.0 |
| 10.101.99.17/23 | N.N.nnnnnnnh.H | 255.255.254.0 | 10.101.98.0 |
| 209.165.200.227/27 | N.N.N.nnnhhhhh | 255.255.255.224 | 209.165.200.224 |
| 172.31.45.252/24 | N.N.N.H | 255.255.255.0 | 172.31.45.0 |
| 10.1.8.200/26 | N.N.N.nnhhhhhh | 255.255.255.192 | 10.1.8.192 |
| 172.16.117.77/20 | N.N.nnnnhhhh.H | 255.255.240.0 | 172.16.112.0 |
| 10.1.1.101/25 | N.N.N.nhhhhhhh | 255.255.255.128 | 10.1.1.0 |
| 209.165.202.140/27 | N.N.N.nnnhhhhh | 255.255.255.224 | 209.165.202.128 |
| 192.168.28.45/28 | N.N.N.nnnnhhhh | 255.255.255.240 | 192.168.28.32 |
Step 2: Analyze the table below and list the range of host and broadcast addresses given a network/prefix mask pair.
The first row shows an example of how the table should be completed.
| IP Address/Prefix | First Host Address | Last Host Address | Broadcast Address |
| 192.168.10.10/24 | 192.168.10.1 | 192.168.10.254 | 192.168.10.255 |
| 10.101.99.17/23 | 10.101.98.1 | 10.101.99.254 | 10.101.99.255 |
| 209.165.200.227/27 | 209.165.200.225 | 209.165.200.254 | 209.165.200.255 |
| 172.31.45.252/24 | 172.31.45.1 | 172.31.45.254 | 172.31.45.255 |
| 10.1.8.200/26 | 10.1.8.193 | 10.1.8.254 | 10.1.8.255 |
| 172.16.117.77/20 | 172.16.112.1 | 172.16.127.254 | 172.16.127.255 |
| 10.1.1.101/25 | 10.1.1.1 | 10.1.1.126 | 10.1.1.127 |
| 209.165.202.140/27 | 209.165.202.129 | 209.165.202.158 | 209.165.202.159 |
| 192.168.28.45/28 | 192.168.28.33 | 192.168.28.46 | 192.168.28.47 |
Part 2: Classify IPv4 Addresses
In Part 2, you will identify and classify several examples of IPv4 addresses.
Step 1: Analyze the table shown below and identify the type of address (network, host, multicast, or broadcast address).
The first row shows an example of how the table should be completed.
| IP Address | Subnet Mask | Address Type |
| 10.1.1.1 | 255.255.255.252 | host |
| 192.168.33.63 | 255.255.255.192 | broadcast |
| 239.192.1.100 | 255.252.0.0 | multicast |
| 172.25.12.52 | 255.255.255.0 | host |
| 10.255.0.0 | 255.0.0.0 | host |
| 172.16.128.48 | 255.255.255.240 | network |
| 209.165.202.159 | 255.255.255.224 | broadcast |
| 172.16.0.255 | 255.255.0.0 | host |
| 224.10.1.11 | 255.255.255.0 | multicast |
Step 2: Analyze the table shown below and identify the address as public or private.
| IP Address/Prefix | Public or Private |
| 209.165.201.30/27 | Public |
| 192.168.255.253/24 | Private |
| 10.100.11.103/16 | Private |
| 172.30.1.100/28 | Private |
| 192.31.7.11/24 | Public |
| 172.20.18.150/22 | Private |
| 128.107.10.1/16 | Public |
| 192.135.250.10/24 | Public |
| 64.104.0.11/16 | Public |
Step 3: Analyze the table shown below and identify whether the address/prefix pair is a valid host address.
| IP Address/Prefix | Valid Host Address? | Reason |
| 127.1.0.10/24 | No | Loopback |
| 172.16.255.0/16 | Yes | Host address |
| 241.19.10.100/24 | No | Reserved |
| 192.168.0.254/24 | Yes | Host address |
| 192.31.7.255/24 | No | Broadcast |
| 64.102.255.255/14 | Yes | Host address |
| 224.0.0.5/16 | No | Multicast |
| 10.0.255.255/8 | Yes | Host address |
| 198.133.219.8/24 | Yes | Host address |
Reflection
Why should we continue to study and learn about IPv4 addressing if the available IPv4 address space is depleted?
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Many organizations will continue to use the private IPv4 address space for their internal networking needs. The public IPv4 addresses will be used for many years to come.