Real-World Examples of Private and Public IP Usage

Understanding the difference between private and public IP addresses on paper is one thing. Seeing how they actually work in the real world is where it all clicks. In this post, we will walk through practical network scenarios that show exactly how these two types of addresses are used every day, in homes, businesses, and across the internet.

Quick Recap: Private vs. Public

Before diving into examples, here is a quick refresher. Private IP addresses are used inside networks and are not routable on the public internet. Public IP addresses are assigned by Internet Service Providers (ISPs) and are reachable from anywhere on the internet.

The three private IP address ranges are:

• 10.0.0.0 to 10.255.255.255
• 172.16.0.0 to 172.31.255.255
• 192.168.0.0 to 192.168.255.255

Everything else (outside these ranges) is considered a public IP address. Now, let us look at some real-world IP examples to see these in action.

Scenario 1: Your Home Network

When you connect your laptop to your home Wi-Fi, your router assigns it a private IP address, something like 192.168.1.105. Your phone might get 192.168.1.106. These addresses are only meaningful inside your home network.

Your router, however, has two IP addresses: one private-facing (like 192.168.1.1) and one public-facing (assigned by your ISP, such as 203.0.113.50). When you visit a website, your router performs Network Address Translation (NAT), replacing your private address with the public one before the traffic leaves your network.

You can check your private IP on a Windows machine by running:

ipconfig

You will see output similar to:

Wireless LAN adapter Wi-Fi:
   IPv4 Address. . . . . . . . . . . : 192.168.1.105
   Subnet Mask . . . . . . . . . . . : 255.255.255.0
   Default Gateway . . . . . . . . . : 192.168.1.1

To find your public IP, a website like whatismyip.com will show you the address your ISP has assigned to your router.

Scenario 2: A Small Business Office

In a typical small office, the IT team might configure the internal network using the 10.10.0.0/24 range. Workstations, printers, and servers all receive private addresses in this block. A single public IP address is assigned to the firewall by the ISP, and NAT handles all outbound traffic from every device behind it.

This is one of the most common IP address applications in business environments. It conserves public IP space and adds a layer of separation between internal resources and the outside world.

Scenario 3: Web Servers and Cloud Hosting

When a company hosts a public website, that web server needs a public IP address so users across the internet can reach it. For example, if you run the following command:

nslookup cisco.com

You will get back a public IP address like:

Name:    cisco.com
Address: 72.163.4.185

That address is publicly routable. Anyone on the internet can send traffic to it directly. This is a fundamental difference from the private addresses inside your home or office.

Scenario 4: Large Enterprise with Multiple Sites

Larger organizations often use the 10.0.0.0/8 private range because it provides millions of addresses. Each branch office might use a different subnet, such as 10.1.0.0/24 for headquarters and 10.2.0.0/24 for a remote office. These sites connect over a VPN or dedicated WAN link, allowing private address communication between locations without exposing internal traffic to the public internet.

This kind of design is one of the most important real-world IP examples for understanding how enterprise networks are structured.

Why This Matters for the CCST Exam

The CCST Networking exam expects you to recognize private address ranges and understand how they are applied in common network scenarios. You should be able to look at an IP address and identify whether it is private or public, and explain the role each plays in a network design. These are not abstract concepts; they are the foundation of how nearly every network on the planet operates.

What's Next

Now that you understand how private and public addresses are used in real-world situations, it is time to look at how IP addresses are broken down into network and host portions. The next post in this series covers subnet masks and how they define the boundaries of a network, a critical concept as you build toward full addressing fluency.