NAT in Action – Real World Examples & Simple Diagrams

In the previous post, we talked about what NAT (Network Address Translation) is and how it helps your home or office devices share a single internet connection.

Now, let’s take a closer look at how NAT actually works, what types of NAT exist, and how it plays out in real-world situations like gaming, hosting, or using video calls.

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📊 A Simple Diagram of NAT at Home

Let’s visualize a basic home setup:

+-----------------------------+
|         Home Wi-Fi Router    |
|    Public IP: 103.21.45.18   |
+---------------+---------------+
|
---------------------------
|             |            |
Phone        Laptop       Printer
IP:           IP:          IP:
192.168.0.2  192.168.0.3  192.168.0.4

All three devices share the same public IP (103.21.45.18), but have different private IPs inside the home. Your router’s NAT feature handles translating between them, keeping everything in sync.

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💬 Real-World Scenario #1: Video Calls or Online Games

Let’s say you're playing a multiplayer game or on a Zoom call:

1. Your gaming PC (192.168.0.5) sends traffic to the game server.

2. NAT changes the IP to your public IP and keeps track of the port used.

3. The game server replies to your public IP + port.

4. NAT checks its memory and says:
   “Ah, this reply is for 192.168.0.5 – I’ll send it back there!”

This is where PAT (Port Address Translation) kicks in—it uses different ports to keep multiple connections from different devices separated.

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🧰 Real-World Scenario #2: Hosting a Server at Home

If you're hosting a game server or a local website and want friends to access it over the internet, you’ll run into an issue:

By default, NAT doesn’t let outside traffic come in.

This is by design, for safety.

But you can set up something called Port Forwarding:

• Tell your router: “Hey, if someone connects to my public IP on port 8080, send it to my PC at 192.168.0.5:8080.”

This lets external users access your server without exposing everything else.

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⚙️ Different Types of NAT – Quick & Easy Breakdown

Type	Description	Common Use
Static NAT	One fixed private IP ↔ one fixed public IP	Corporates, data centers
Dynamic NAT	Private IPs use a pool of public IPs	Less common at home
PAT (NAT Overload)	Many private IPs share one public IP using ports	Most home networks

Most home users are using PAT—you might see it called NAT Overload.

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🧩 Issues You Might Face with NAT

Here are a few real-world hiccups caused by NAT:

• "Strict NAT Type" in online games – Makes it harder to connect to other players.
• Peer-to-peer apps (like torrents or video chats) might have trouble unless ports are forwarded.
• Double NAT – Happens when you’re behind two routers (like an ISP modem + your own router). It can break some services.

👉 Pro tip: You can use DMZ (not recommended for security), UPnP, or manually forward ports to fix these.

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🧠 Bonus Tip: Check Your IPs

• What’s my public IP?
  Just Google: what is my IP

• Private IP (on phone or PC)?

  • On Windows: ipconfig in Command Prompt

  • On macOS/Linux: ifconfig or look in Network Settings

  • On Android: Go to Wi-Fi settings → your network → Advanced

  • On iPhone: Settings → Wi-Fi → (i) on your connected network

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🎯 Final Thoughts

NAT is one of those tech things that just works in the background—but once you understand it, a whole new layer of the internet makes sense. From better gaming setups to hosting your own site or solving weird connection problems, knowing how NAT functions is super handy.

So next time you’re tinkering with your router settings or wondering why your game says “NAT Type: Strict”... now you know what’s going on!